JP7615731B2 - Vehicle notification device - Google Patents

Description

The present invention relates to a vehicle warning device that warns the driver of the vehicle of the presence of an oncoming vehicle.

One such vehicle warning device (hereinafter also referred to as the "conventional device") warns the driver of the vehicle when the vehicle is stopped and the right turn indicator is activated, and the time it takes for an oncoming vehicle to reach the predicted right turn trajectory of the vehicle is less than a predetermined time (see, for example, Patent Document 1). This warning process is also referred to as the "oncoming vehicle warning process" or "notification process."

JP 2004-280453 A

The predicted right turn trajectory (i.e., the predicted driving route of the vehicle) can be obtained, for example, based on the steering angle of the vehicle at the current time. In this case, if the driver of the vehicle has not started a steering operation to turn right, the oncoming vehicle notification process is not executed.

However, it is desirable to start the oncoming vehicle notification process as early as possible (for example, before the driver starts steering to turn right). On the other hand, it is desirable to avoid unnecessarily executing the oncoming vehicle notification process as much as possible.

Therefore, one of the objectives of the present invention is to provide a vehicle warning device that is capable of initiating a warning operation to notify the driver of the presence of an oncoming vehicle early and is unlikely to perform an unnecessary warning operation.

The vehicle notification device (hereinafter referred to as the "device of the present invention") for achieving the above-mentioned objective includes a surrounding sensor, a turn signal, an alarm, and a control unit.

The surrounding sensor (front camera 41)
"Surrounding information" is acquired, which includes information about objects in the area ahead of the host vehicle and about markings on the road on which the host vehicle is traveling.

The direction indicator (direction indicator 43) is
The state of the light is changed from a non-operating state (light-off state) to an operating state (flashing state) by a predetermined operation by the driver of the vehicle.

The alarm (display 46 and speaker 47)
An "alert operation" is performed to alert the driver of the presence of another vehicle that the driver should be aware of.

The control units (ECU 21 to ECU 29, etc.)
The annunciator is controlled (see steps 630 and 640, etc.).

In addition, the control unit
Based on the surrounding information, a determination is made as to whether or not there is an "oncoming vehicle" that is another vehicle traveling in the "opposing lane" relative to the lane in which the vehicle is traveling, approaching the vehicle from in front of the vehicle, and whose "predicted driving path" is passing through a "specific direction" that is either to the right or left of the vehicle's current position.

Furthermore, the control unit
When it is determined that a "predetermined specific condition" is satisfied in either of the following cases: the turn indicator corresponding to the specific direction of the vehicle among the direction indicators is in the activated state, the presence of an oncoming vehicle is determined, and it is predicted that there is a high possibility that the vehicle will start turning in the specific direction, or the driver of the vehicle should be aware of the presence of the oncoming vehicle before the vehicle starts turning in the specific direction (see, for example, step 645: Yes, step 650: Yes, etc. in Figure 6), the alarm is caused to start the alarm operation (for example, step 630).

The specific direction is, for example, the right in left-hand traffic areas (areas where vehicles drive on the left side of the road) and the left in right-hand traffic areas (areas where vehicles drive on the right side of the road). In other words, the specific direction is the direction in which the host vehicle crosses the oncoming lane when turning right or left. If the host vehicle is driving in an area where the host vehicle drives on the left, and the oncoming vehicle's predicted driving path passes to the right of the host vehicle, the host vehicle may collide with the oncoming vehicle if the host vehicle turns right. Therefore, even before the host vehicle starts turning in a specific direction, when a predetermined specific condition is met, which is met when it is predicted (estimated) that the host vehicle is highly likely to start turning in the specific direction, a notification operation is initiated.

In other words, even if the driver of the vehicle has not started steering to turn right, the notification operation (oncoming vehicle notification process) is initiated when the specific conditions are met. On the other hand, if the specific conditions are not met, the notification operation is not initiated. Therefore, according to the device of the present invention, the notification operation (notifying the driver of the presence of an oncoming vehicle that the driver should be aware of) can be initiated before the driver starts steering, and the possibility of the notification operation being performed unnecessarily can be reduced.

In some embodiments of the device of the present invention,
The control unit
A determination is made based on the surrounding information as to whether or not a condition (i.e., a specific area condition) is met that is met when a specific area (e.g., a right-turn passing area) that includes a part of the area through which the vehicle passes when turning in the specific direction and that is predetermined for the vehicle does not include a dividing line on the specific direction side of a pair of (left and right) dividing lines that define the driving lane (i.e., a specific dividing line, see Lt1, Lt2, Lt3, Lt4, etc.) is not included based on the surrounding information (e.g., step 645).

Furthermore, the control unit
If it is determined that the specific area condition is met, it is determined that the specific condition is met, and the alarm is caused to start an alarm operation (for example, see the case where the process proceeds from "Yes" in step 645 to step 630).

If the vehicle's turn signal corresponding to the "specific direction" is activated and the specific area does not include a specific lane marking (if the specific area condition is met), it is highly likely that the vehicle is about to turn in the specific direction at the intersection. Therefore, in this case, a notification operation is initiated.

In some embodiments of the device of the present invention,
The control unit
determining whether a turning standby condition is satisfied based on the surrounding information;
determining that the specific condition is satisfied when it is determined that the turning standby condition is satisfied;
It is configured as follows.
The turning waiting condition is a condition that is met when the specific area includes the specific lane marking (step 645: No) and the vehicle's traveling speed is lower than a predetermined first threshold speed (Vth1) (step 650: Yes).

There are cases where the possibility of a collision with an oncoming vehicle increases when the vehicle turns in a specific direction at a location other than an intersection. In these cases, it is desirable to perform a notification operation.

When the host vehicle turns in a specific direction at a location other than an intersection, the specific lane marking is often included in the specific passing area. In addition, in many cases, the driver reduces the vehicle's traveling speed before turning the vehicle in a specific direction. Therefore, when the host vehicle is about to turn in a specific direction at a location other than an intersection, the turn waiting condition is met. Therefore, even when the host vehicle turns in a specific direction at a location other than an intersection, the notification operation can be performed appropriately.

On the other hand, for example, a driver may activate a turn signal corresponding to a specific direction to change lanes from the leftmost lane in a left-hand traffic area to a lane to the right of that lane (not an oncoming lane, but generally called an overtaking lane). In this case, the vehicle's traveling speed is often greater than the first threshold speed, so the turning wait condition is not met and therefore no notification operation is performed. This reduces the possibility that a notification operation is performed unnecessarily when a lane change is being performed.

In some embodiments of the device of the present invention (e.g., the first variant),
The control unit
A determination is made based on the surrounding information as to whether or not a preceding vehicle, which is another vehicle located immediately in front of the host vehicle, is present (step 820 in FIG. 8 );
When it is determined that the preceding vehicle is present, it is determined whether or not the speed of the preceding vehicle is greater than a predetermined preceding vehicle turning threshold speed (Vth2);
When it is determined that the speed of the preceding vehicle is greater than the preceding vehicle turning threshold speed, it is determined that the specific condition is satisfied (step 820: Yes).
It is configured as follows.

For example, the driver of the leading vehicle may start turning in a specific direction at an intersection without noticing the presence of an oncoming vehicle. Or, the driver of the leading vehicle may attempt to turn in a specific direction at an intersection before the oncoming vehicle reaches the intersection. In these cases, the driver of the vehicle may mistakenly believe that there is no oncoming vehicle. Therefore, in the above embodiment, when it is determined that the speed of the leading vehicle is greater than the leading vehicle turning threshold speed, it is determined that the specific condition is met, and a notification operation is performed.

In some embodiments of the device of the present invention (e.g., the second variant),
The control unit
determining whether or not a preceding vehicle, which is another vehicle located immediately before the host vehicle, is present based on the surrounding information;
If it is determined that the preceding vehicle is present, it is determined based on the surrounding information whether or not the preceding vehicle has started turning in the specific direction (step 1020 in FIG. 10 );
When it is determined that the preceding vehicle has started turning in the specific direction, it is determined that the specific condition is satisfied (step 1020: Yes).
It is configured as follows.

According to this aspect, even if the driver of the leading vehicle starts turning in a specific direction at an intersection without noticing the presence of an oncoming vehicle, or if the driver attempts to turn in a specific direction at an intersection before the oncoming vehicle reaches the intersection, it is determined that the specific condition is met. Therefore, a notification operation is performed.

In some embodiments of the device of the present invention (e.g., the third variant),
The control unit
Determine whether the oncoming lane in which the oncoming vehicle is traveling and the traveling lane of the host vehicle are adjacent to each other based on the surrounding information (step 1245 in FIG. 12 );
When it is determined that the oncoming lane in which the oncoming vehicle is traveling and the traveling lane of the host vehicle are adjacent to each other, it is determined that the specific condition is established (step 1245: Yes).
It is configured as follows.

When an oncoming vehicle is traveling in a lane adjacent to the driving lane on the specific direction side, if the turn signal of the vehicle's own vehicle corresponding to the specific direction is in an activated state, there is a high possibility that the vehicle will cross the lane in which the oncoming vehicle is traveling. In other words, when an oncoming vehicle is traveling in a lane adjacent to the driving lane on the specific direction side, the driver of the vehicle should be aware of the presence of the oncoming vehicle before the vehicle starts turning in the specific direction. Therefore, in the above embodiment, when it is determined that the oncoming lane in which the oncoming vehicle is traveling and the driving lane of the vehicle are adjacent to each other, it is determined that the specific condition is met. Therefore, in this case, a notification operation is performed.

In some embodiments of the device of the present invention (e.g., the third variant),
The control unit
Determine whether a lateral distance (|Dx|), which is a distance in a width direction of the host vehicle from the host vehicle to the oncoming vehicle, is smaller than a predetermined first threshold distance (Dth1) based on the surrounding information (step 1250 in FIG. 12 );
When it is determined that the lateral distance is smaller than the first threshold distance, it is determined that the specific condition is satisfied (step 1250: Yes).
It is configured as follows.

When the lateral distance from the host vehicle to the oncoming vehicle is small, if the turn signal of the host vehicle corresponding to the specific direction is in an activated state, there is a possibility that the host vehicle will approach the oncoming vehicle immediately after starting to operate it. In other words, when the lateral distance from the host vehicle to the oncoming vehicle is small, this is a case in which the driver of the host vehicle should be aware of the presence of the oncoming vehicle before the host vehicle starts to turn in the specific direction. Therefore, in the above embodiment, when it is determined that the lateral distance is smaller than the first threshold distance, it is determined that the specific condition is met. Therefore, in this case, a notification operation is performed.

In some embodiments of the device of the present invention (e.g., the fourth variant),
The control unit
Determine whether or not there is a crossing vehicle that is a vehicle different from the oncoming vehicle and whose predicted travel route intersects with the predicted travel route of the oncoming vehicle based on the surrounding information (step 1450 of FIG. 14 );
When the prohibition condition including the condition that the crossing vehicle is present is satisfied, the execution of the notification operation is prohibited (step 1450: No).
It is configured as follows.

In some embodiments of the device of the present invention (for example, a variant of the fourth variant),
The control unit
Determine whether or not there is a crossing vehicle that is a vehicle different from the oncoming vehicle and whose predicted travel route intersects with the predicted route of the host vehicle based on the surrounding information (step 1450 of FIG. 14 );
When the prohibition condition including the condition that the crossing vehicle is present is satisfied, the execution of the notification operation is prohibited (step 1450: No).
It is configured as follows.

When the driver of the vehicle recognizes a crossing vehicle, there is a high possibility that the driver will slow down the vehicle. Therefore, in some of the above embodiments, when prohibition conditions are met, including the condition that a crossing vehicle is present, the execution of the notification operation is prohibited. This reduces the possibility that the notification operation is executed unnecessarily.

In some embodiments of the device of the present invention (e.g., the sixth variant),
The control unit
Determine whether or not a lateral distance (|Dx|), which is a distance in a width direction of the host vehicle from the host vehicle to the oncoming vehicle, is equal to or greater than a lateral threshold distance (Dth3, Dth4) that increases as the traveling speed of the host vehicle increases (steps 1950 and 1955 in FIG. 19 ), based on the surrounding information;
When a prohibition condition including a condition that the lateral distance is equal to or greater than the lateral threshold distance is satisfied, the execution of the announcing operation is prohibited (step 1950: No, step 1955: No).
It is configured as follows.

The slower the vehicle's traveling speed, the longer the time (intersection arrival time) until the vehicle reaches the predicted traveling path of the oncoming vehicle (predicted path of the oncoming vehicle). In addition, the longer the distance between the vehicle and the oncoming vehicle in the vehicle width direction (lateral distance (|Dx|)), the longer the intersection arrival time. If the intersection arrival time is longer, the driver is more likely to recognize the presence of an oncoming vehicle before the vehicle reaches the predicted path of the oncoming vehicle. Therefore, in the above embodiment, if a prohibition condition is met that includes the condition that the lateral distance is equal to or greater than the lateral threshold distance, the execution of the notification operation is prohibited. This reduces the possibility of the notification operation being executed unnecessarily.

In the above "embodiment of comparing the lateral distance with the lateral threshold distance", more specifically,
The control unit
When the traveling speed of the host vehicle is equal to or lower than a fourth threshold speed (Vth4), it is determined based on the surrounding information whether or not a lateral distance, which is a distance in a width direction of the host vehicle from the host vehicle to the oncoming vehicle, is equal to or higher than a third threshold distance (Dth3) (steps 1945 and 1950 in FIG. 19 );
When a prohibition condition is satisfied, the execution of the notification operation is prohibited (step 1950: No), the prohibition condition including a condition that the traveling speed of the host vehicle is equal to or less than the fourth threshold speed and the lateral distance is equal to or greater than the third threshold distance is satisfied.
It is configured as follows.

Similarly, in the above "embodiment for comparing the lateral distance with the lateral threshold distance", more specifically, the control unit
When the traveling speed of the host vehicle is greater than a fourth threshold speed (Vth4), it is determined based on the surrounding information whether or not a "lateral distance, which is a distance in the width direction of the host vehicle from the host vehicle to the oncoming vehicle" is equal to or greater than a "fourth threshold distance (Dth4) greater than the third threshold distance" (steps 1945 and 1955 in FIG. 19 ).
When a prohibition condition is satisfied, the execution of the notification operation is prohibited (step 1955: No), the prohibition condition including a condition that the traveling speed of the host vehicle is higher than the fourth threshold and the lateral distance is equal to or greater than the fourth threshold distance is satisfied.
It is configured as follows.

Some embodiments of the device of the present invention (e.g., the seventh variant) are
A steering angle sensor (45) for detecting an operation angle of a steering wheel of the vehicle;
a brake pedal operation state sensor (48) for detecting an operation state of a brake pedal of the vehicle;
Equipped with.

Furthermore, the control unit of this embodiment determines whether a prohibition condition, the prerequisite for which is that all of the conditions described below are satisfied, is satisfied, and if the prohibition condition is satisfied, prohibits the execution of the notification operation.
- The detected operating angle (θs) is a value in the opposite direction to the direction that would turn the vehicle so as to cross the oncoming lane, or the detected steering angle is a value in the direction that would turn the vehicle so as to cross the oncoming lane and the magnitude of the steering angle is smaller than a threshold angle (θth) (Step 2050 in FIG. 20: Yes).
The detected operation state of the brake pedal indicates that the brake pedal is being operated (Step 2055 in FIG. 20: Yes).
The traveling speed of the host vehicle is equal to or lower than a fifth threshold speed (Vtht) (Step 2060 in FIG. 20: Yes).

If the driver of the vehicle recognizes the presence of an oncoming vehicle, there is a high possibility that the driver will decelerate the vehicle before starting to turn in the specific direction. Therefore, if the brake pedal is operated, there is a high possibility that the driver recognizes the presence of an oncoming vehicle. On the other hand, when the steering wheel is operated in the specific direction by an angle greater than the threshold angle (θth), there is a high possibility that the driver does not recognize the presence of an oncoming vehicle. Furthermore, when the traveling speed of the vehicle is greater than the fifth threshold speed, there is a high possibility that the driver does not recognize the presence of an oncoming vehicle. Therefore, according to the above embodiment, it is possible to reduce the possibility that a warning operation will be performed when there is a high possibility that the driver of the vehicle recognizes the presence of an oncoming vehicle.

In some embodiments of the device of the present invention (e.g., the fifth variant), the alarm includes a speaker (47) that produces sound and a display (46) that displays information.

Furthermore, the control unit
When it is determined that a longitudinal distance between the vehicle determined to be an oncoming vehicle and the own vehicle is smaller than a predetermined second threshold distance and a target traveling speed of the vehicle determined to be an oncoming vehicle is equal to or lower than a predetermined third threshold speed, it is determined that the vehicle determined to be an oncoming vehicle has stopped;
When it is determined that the vehicle that was determined to be the oncoming vehicle has stopped, a stop history indicating that it has been determined that the vehicle that was determined to be the oncoming vehicle has stopped is stored;
When it is determined that the specific condition is satisfied and the stop history is not stored, a notification operation using both the speaker and the display is started (step 1650 in FIG. 16: No, steps 1630 and 1632);
When it is determined that the specific condition is satisfied and the stop history is stored, a notification operation is started using the speaker without using the display (step 1650 in FIG. 16: Yes, step 1632).
It is configured as follows.

When an oncoming vehicle stops (temporarily stops), the time that the oncoming vehicle is within the field of vision of the driver of the vehicle increases. Therefore, the driver of the vehicle is more likely to notice the oncoming vehicle. Therefore, by performing a notification operation using the speaker without using the display when the stop history is stored, it is possible to reduce the possibility that the driver will find the display annoying.

Similarly, in some embodiments of the device of the present invention (e.g., a variant of the fifth variant),
The control unit
When it is determined that a longitudinal distance between the vehicle determined to be an oncoming vehicle and the own vehicle is smaller than a predetermined second threshold distance and a target traveling speed of the vehicle determined to be an oncoming vehicle is equal to or lower than a predetermined third threshold speed, it is determined that the vehicle determined to be an oncoming vehicle has stopped;
When it is determined that the vehicle that was determined to be the oncoming vehicle has stopped, a stop history indicating that it has been determined that the vehicle that was determined to be the oncoming vehicle has stopped is stored;
When it is determined that the specific condition is satisfied and the stop history is not stored, the notification operation is started;
prohibiting the notification operation when the stop history is stored when it is determined that the specific condition is satisfied;
It is configured as follows.

According to this embodiment, if it is highly likely that the driver of the vehicle is aware of the oncoming vehicle because the oncoming vehicle has stopped (stop history is stored), the notification operation is prohibited. Therefore, it is possible to reduce the possibility that the notification operation will be performed when it is highly likely that the driver of the vehicle is aware of the presence of an oncoming vehicle.

In some embodiments of the device of the present invention (e.g., the eighth variant),
The control unit
Determine whether or not a predetermined first notification end condition, which is established when it is highly likely that the host vehicle has stopped turning in the specific direction, is established based on a parameter corresponding to the detected steering angle (step 2210 in FIG. 22 );
When it is determined that the first notification end condition is satisfied during the execution of the notification operation, the notification operation is ended (step 2210 in FIG. 22 : Yes, step 640 in FIG. 22 ).
It is configured as follows.

The first notification termination condition is, for example, a condition that is met when the steering wheel of the vehicle is operated in the opposite direction to a specific direction at an angular velocity greater than a predetermined threshold angular velocity. If it is determined that the first notification termination condition is met based on the operation state, the notification operation is terminated.

In some embodiments of the device of the present invention (e.g., the eighth variant),
The control unit
When the state in which it is determined that the oncoming vehicle does not exist during the execution of the notification operation continues for a third threshold time or more (see steps 2255 and 2270 in FIG. 22), the notification operation is terminated (step 2265: Yes, step 640 in FIG. 22).
It is configured as follows.

There may be cases where an oncoming vehicle is temporarily determined not to exist when it is actually present due to a temporary decrease in the detection accuracy of the surrounding sensors. In this case, a situation may occur where the notification operation ends because it was erroneously determined that an oncoming vehicle does not exist, and then the notification operation is resumed immediately because it was correctly determined that an oncoming vehicle does exist. In this case, there is a high possibility that the driver will feel uncomfortable. Therefore, the notification operation continues until the state in which it is determined that an oncoming vehicle does not exist continues for the third threshold time. Then, the notification operation ends when it is certain that an oncoming vehicle does not exist.

In some embodiments of the device of the present invention,
The control unit
During the execution of the notification operation,
The direction indicator corresponding to the specific direction of the host vehicle changes from the activated state to the deactivated state (condition (C1)), and
When the vehicle is stopped (condition (C3),
and terminating the notification operation in at least one of the following cases:
(see step 635 in FIG. 6).

In the above description, in order to aid in understanding the present invention, the names and/or symbols used in the embodiments described below are enclosed in parentheses with respect to the configuration of the invention corresponding to the embodiments. However, each component of the present invention is not limited to the embodiments defined by the above names and/or symbols. Other objects, other features, and associated advantages of the present invention will be easily understood from the description of the embodiments of the present invention described below with reference to the drawings.

1 is a schematic diagram of a vehicle (this vehicle) on which a vehicle notification device (this notification device) according to an embodiment of the present invention is mounted. FIG. 2 is a block diagram of the notification device. 11 is a diagram showing an example in which the oncoming vehicle warning process is executed by the warning device based on a route crossing warning condition and a first advance warning condition. FIG. 11 is a diagram showing an example in which the oncoming vehicle warning process is executed by the warning device based on a route crossing warning condition and a second advance warning condition. FIG. FIG. 13 is a diagram showing an example in which the second advance notification condition is not satisfied. 4 is a flowchart showing an oncoming vehicle notification determination processing routine executed by the present notification device. 13 is a diagram showing an example in which an oncoming vehicle warning process is executed based on a third advance warning condition by a warning device (first modified device) for a vehicle according to a first modified embodiment of an embodiment of the present invention. FIG. 10 is a flowchart showing an oncoming vehicle notification determination process routine executed by a first modification device. 13 is a diagram showing an example in which an oncoming vehicle warning process is executed based on a fourth advance warning condition by a vehicle warning device (second modified device) according to a second modified embodiment of the present invention. FIG. 10 is a flowchart showing an oncoming vehicle notification determination process routine executed by a second modification device. A figure showing an example in which an oncoming vehicle warning process is executed based on the fifth advance warning condition or the sixth advance warning condition by a vehicle warning device (third modified device) according to a third modified embodiment of the present invention. 10 is a flowchart illustrating an oncoming vehicle notification determination process routine executed by a third modification device. 13 is a diagram showing an example in which an oncoming vehicle warning process is executed based on a seventh advance warning condition by a vehicle warning device (fourth modified device) according to a fourth modified example of an embodiment of the present invention. FIG. 13 is a flowchart showing an oncoming vehicle notification determination process routine executed by a fourth modification device. 13 is a diagram showing an example in which an oncoming vehicle warning process is executed by a vehicle warning device (fifth modified device) according to a fifth modified embodiment of the present invention, based on a stop history of an oncoming vehicle. FIG. 13 is a flowchart illustrating an oncoming vehicle notification determination process routine executed by a fifth modification device. 13 is a diagram showing an example in which an oncoming vehicle warning process is executed based on an eighth advance warning condition by a vehicle warning device (sixth modified device) according to a sixth modified embodiment of the present invention. FIG. 13 is a diagram showing an example in which the oncoming vehicle warning process is executed by the sixth modification device based on the ninth advance warning condition. FIG. 13 is a flowchart illustrating an oncoming vehicle notification determination process routine executed by a sixth modification device. 13 is a flowchart illustrating an oncoming vehicle notification determination process routine executed by a vehicle notification device (seventh modified device) according to a seventh modified example of the embodiment of the present invention. 13 is a flowchart illustrating an oncoming vehicle notification determination process routine executed by a vehicle notification device (eighth modified device) according to an eighth modified example of the embodiment of the present invention. 23 is a flowchart illustrating an oncoming vehicle notification end process routine executed by the eighth modification device.

(composition)
Hereinafter, a vehicle notification device (hereinafter also referred to as "this notification device") according to an embodiment of the present invention will be described with reference to the drawings. This notification device is applied to a vehicle 10 shown in Fig. 1. As can be seen from Fig. 2, which is a block diagram of this notification device, this notification device includes a vehicle control ECU 21 which is an electronic control unit (ECU). Hereinafter, the vehicle control ECU 21 will also be simply referred to as ECU 21.

The ECU 21 includes as its main components a microcomputer equipped with a CPU 31, a non-volatile memory 32, and a RAM 33. The CPU 31 sequentially executes predetermined programs (routines) to read data, perform numerical calculations, and output the results of the calculations. The non-volatile memory 32 includes a ROM and a readable and writable flash memory. The non-volatile memory 32 stores the programs executed by the CPU 31 and lookup tables (maps) referenced when the programs are executed. The RAM 33 temporarily stores data referenced by the CPU 31.

The ECU 21 is connected to a forward camera 41, a turn signal lever sensor 42, a direction indicator 43, a vehicle speed sensor 44, a steering angle sensor 45, a display 46, a speaker 47, and a brake pedal operation amount sensor (brake pedal operation state sensor) 48. For convenience, the forward camera 41 is also referred to as the "surroundings sensor." For convenience, the display 46 and the speaker 47 are also referred to as the "alarm."

(Configuration - Front camera)
The front camera 41 is disposed in a position near a rear view mirror (room mirror) (not shown) at the top of the passenger compartment of the vehicle 10 (see FIG. 1). The front camera 41 captures a "front image" of the area in front of the vehicle 10 at every predetermined time interval ΔTc (fixed value), and outputs data representing the front image (front image data) to the ECU 21. The horizontal field of view (angle of view, photographing area) of the front camera 41 is in the range from line Lc1 to line Lc2 (see FIG. 1).

The forward image last captured by the forward camera 41 is hereinafter also referred to as the "latest image." The forward image captured by the forward camera 41 immediately before the latest image (i.e., the forward image captured a time interval ΔTc before the time the latest image was captured) is hereinafter also referred to as the "previous image."

In the following description, as shown in FIG. 1, the axis along the left-right direction (vehicle width direction) of the vehicle 10 is referred to as the X-axis, and the axis along the front-rear direction of the vehicle 10 is referred to as the Y-axis. The front end of the vehicle 10, which is the center point of the vehicle 10 in the left-right direction, is the origin where X = 0 and Y = 0. The X coordinate is a positive value in the right direction in the direction of travel when the vehicle 10 moves forward, and a negative value in the left direction in the direction of travel when the vehicle 10 moves forward. The Y coordinate is a positive value in the forward direction of the vehicle 10, and a negative value in the rearward direction of the vehicle 10.

When the ECU 21 receives the forward image data, it detects (extracts) three-dimensional objects, including other vehicles and pedestrians, contained in the forward image, and a pair of dividing lines that define the driving lane (i.e., the lane in which the vehicle 10 is traveling). Hereinafter, the three-dimensional objects detected based on the forward image are also referred to as "camera-detected objects." For convenience, information related to the camera-detected objects and the driving lane detected based on the forward image is also referred to as "surrounding information."

To be more specific about the method of detecting camera-detected objects, the ECU 21 searches for "parts similar to any of the many pre-stored templates (i.e., patterns of other vehicles, pedestrians, etc.)" in the forward image in order to extract a three-dimensional object from the forward image. If the ECU 21 finds a part of the forward image (i.e., a part in the forward image showing a three-dimensional object) that is similar to one of the templates, it extracts the outline of the "three-dimensional object shown in the forward image" that corresponds to that template. That is, the ECU 21 extracts the outline of the three-dimensional object included in the forward image using a pattern matching method.

When the ECU 21 detects a three-dimensional target from the forward image, it acquires the type of the template that corresponds to the three-dimensional target (i.e., the corresponding template) as the type of the three-dimensional target. In this embodiment, the type of the three-dimensional target (i.e., the type of the template pre-stored in the ECU 21) includes "other vehicle."

Furthermore, the ECU 21 acquires the "left edge position" and the "right edge position" of the detected three-dimensional object relative to the vehicle 10 using a well-known method. The left edge position and the right edge position are each represented by a combination of an X coordinate value and a Y coordinate value.

The ECU 21 obtains the distance in the Y-axis direction between the front end of the vehicle 10 and the three-dimensional object as the vertical position Dy. Specifically, the ECU 21 obtains the smaller of the Y coordinate value of the left end position of the three-dimensional object and the Y coordinate value of the right end position of the three-dimensional object as the vertical position Dy.

In addition, the ECU 21 acquires the X-coordinate value of the three-dimensional object as the lateral position Dx. Specifically, the ECU 21 acquires the average value of the X-coordinate value of the left end position and the X-coordinate value of the right end position of the three-dimensional object as the lateral position Dx.

At this time, if the type of the three-dimensional target is "other vehicle" and the front (front end) of the three-dimensional target (i.e., the other vehicle) is included in the forward image, the ECU 21 acquires the positions of the left end position (i.e., the left corner of the front end of the other vehicle) and the right end position (i.e., the right corner of the front end of the other vehicle) of the front of the other vehicle included in the forward image, relative to the vehicle 10. Similarly, if the type of the three-dimensional target is "other vehicle" and the rear (rear end) of the three-dimensional target (i.e., the other vehicle) is included in the forward image, the ECU 21 acquires the positions of the left end position (i.e., the left corner of the rear end of the other vehicle) and the right end position (i.e., the right corner of the rear end of the other vehicle) of the rear of the other vehicle included in the forward image, relative to the vehicle 10.

If the three-dimensional object detected in the latest image is also detected in the previous image, the ECU 21 acquires the lateral relative velocity Vx, the longitudinal relative velocity Vy, and the target travel speed Vc of the three-dimensional object. The lateral relative velocity Vx represents the relative velocity of the three-dimensional object in the X-axis direction with respect to the vehicle 10. The longitudinal relative velocity Vy represents the relative velocity of the three-dimensional object in the Y-axis direction with respect to the vehicle 10. The target travel speed Vc represents the magnitude of the movement speed of the three-dimensional object relative to the road surface (ground).

More specifically, the ECU 21 obtains the difference between the "lateral position Dx obtained based on the latest image" and the "previous lateral position Dpx, which is the lateral position Dx obtained based on the previous image," as the lateral change amount ΔDx (i.e., ΔDx = Dx - Dpx). In addition, the ECU 21 obtains the lateral relative velocity Vx by dividing the lateral change amount ΔDx by the time interval ΔTc (i.e., Vx = ΔDx/ΔTc).

Similarly, ECU 21 obtains the difference between the "vertical position Dy obtained based on the latest image" and the "previous vertical position Dpy, which is the vertical position Dy obtained based on the previous image," as the vertical change amount ΔDy (i.e., ΔDy=Dy-Dpy). In addition, ECU 21 obtains the vertical relative velocity Vy by dividing the vertical change amount ΔDy by the time interval ΔTc (i.e., Vy=ΔDy/ΔTc).

Furthermore, the ECU 21 obtains the sum of the vehicle speed Vs, which is the traveling speed of the vehicle 10, and the longitudinal relative speed Vy as the target longitudinal speed Vcy (i.e., Vcy = Vs + Vy). In addition, the ECU 21 obtains the square root of the sum of the square of the target longitudinal speed Vcy and the square of the lateral relative speed Vx as the target traveling speed Vc (i.e., Vc = ( ^Vcy2 + ^Vx2 ) ^1/2 ).

Next, a method for detecting a pair of markings (specifically, a left marking and a right marking) that define the driving lane included in the forward image will be described. In this embodiment, the left marking and the right marking are road markings represented by solid or dashed lines in white or yellow. The right marking is, for example, either a center line or a lane boundary line. For convenience, the right marking is also referred to as a "specific marking."

Based on the gradients of hue, brightness, and saturation in the area corresponding to the road surface (ground) in the forward image, the ECU 21 extracts the boundary (demarcation line boundary) between the demarcation lines extending forward (distant) from the front end of the vehicle 10 and the area other than the demarcation lines. Based on the extracted demarcation boundary line, the ECU 21 obtains the positions of the left and right demarcation lines relative to the vehicle 10. The left demarcation line is represented by a set of combinations of "a certain Y coordinate value" and "the X coordinate value of the left demarcation line at that Y coordinate value." Similarly, the right demarcation line is represented by a set of combinations of "a certain Y coordinate value" and "the X coordinate value of the right demarcation line at that Y coordinate value."

In addition, the ECU 21 determines whether a marking line further to the right of the right marking line with respect to the vehicle 10 (hereinafter also referred to as the "adjacent right marking line") has been detected. The adjacent right marking line is a marking line that, together with the right marking line, defines the "lane adjacent to the right of the driving lane." The lane defined by the right marking line and the adjacent right marking line is hereinafter also referred to as the "right adjacent lane."

(Configuration: turn signal lever and turn signal lamp)
The turn signal lever sensor 42 shown in Fig. 2 detects the rotational position (specifically, any one of the neutral position, the right position, and the left position) of the turn signal lever 51a shown in Fig. 1, and outputs a signal indicating the rotational position to the ECU 21. The turn signal lever 51a is disposed on the steering column of the steering wheel 51 of the vehicle 10 so as to extend to the right with respect to the driver of the vehicle 10.

The turn signal lever 51a can rotate (tilt) a predetermined angle in the clockwise and counterclockwise directions with the base of the turn signal lever 51a (i.e., the fixed position of the turn signal lever 51a to the steering column) as the fulcrum (center of rotation). When the turn signal lever 51a is not operated by the driver, the turn signal lever 51a is in a neutral position.

The direction indicators 43 shown in FIG. 2 include a right indicator 43R and a left indicator 43L. The right indicator 43R is a turn signal lamp (yellow light) disposed at the right corner of the front end and the right corner of the rear end of the vehicle 10, as shown in FIG. 1. The left indicator 43L is a turn signal lamp disposed at the left corner of the front end and the left corner of the rear end of the vehicle 10.

The ECU 21 shown in FIG. 2 controls the direction indicator 43 according to the operation state of the turn signal lever 51a (i.e., the signal representing the rotational position received from the turn signal lever sensor 42). Specifically, when the rotational position of the turn signal lever 51a is in the right position (i.e., when the turn signal lever 51a is operated in the clockwise direction), the ECU 21 blinks the right indicator 43R. When the rotational position of the turn signal lever 51a is in the left position (i.e., when the turn signal lever 51a is operated in the counterclockwise direction), the ECU 21 blinks the left indicator 43L. When either the left indicator 43L or the right indicator 43R is blinking, the state of the blinking direction indicator is expressed as "activated state". When either the left indicator 43L or the right indicator 43R is not blinking, the state of the non-blinking direction indicator is expressed as "inactivated state".

(Composition - Other)
The vehicle speed sensor 44 detects the vehicle speed Vs, and outputs a signal indicative of the vehicle speed Vs to the ECU 21. The steering angle sensor 45 detects the steering angle θs, which is the rotation angle of the steering wheel 51, and outputs a signal indicative of the steering angle θs to the ECU 21.

When the steering wheel 51 is in the neutral position, the steering angle θs is "0". The steering angle θs is a positive value when the steering wheel 51 is rotated clockwise relative to the neutral position (i.e., θs>0). On the other hand, the steering angle θs is a negative value when the steering wheel 51 is rotated counterclockwise relative to the neutral position (i.e., θs<0).

The display 46 is a liquid crystal display (LCD) arranged on the instrument panel (not shown) of the vehicle 10 in a position visible to the driver of the vehicle 10. The characters, figures, etc. displayed on the display 46 are controlled by the ECU 21. The speaker 47 is arranged in the passenger compartment of the vehicle 10. The warning sounds, voice messages, etc. played by the speaker 47 are controlled by the ECU 21.

The brake pedal operation amount sensor 48 detects the brake pedal operation amount Bp, which is the amount of operation of the brake pedal 52 operated by the driver to reduce the vehicle speed Vs, and outputs a signal representing the brake pedal operation amount Bp to the ECU 21. When the brake pedal 52 is not operated, the brake pedal operation amount Bp is "0". The greater the amount of operation of the brake pedal 52, the greater the brake pedal operation amount Bp.

(Oncoming vehicle notification process)
Next, the "oncoming vehicle notification process" executed by the ECU 21 will be described on the assumption that the vehicle 10 is traveling in an area where a law stipulates that vehicles must travel on the left side of the road (a left-hand traffic area, for example, Japan or the UK). When the vehicle 10 is turning right and there is a high possibility of colliding with an "oncoming vehicle", the ECU 21 executes the oncoming vehicle notification process. Specifically, the ECU 21 causes the display 46 and the speaker 47 of the vehicle 10 to perform an operation (i.e., a notification operation) to "notify the driver of the vehicle 10 of the presence of an oncoming vehicle". The oncoming vehicle is another vehicle traveling in an oncoming lane, which is a lane opposite to the driving lane. The oncoming lane can be said to be a lane in which the determined vehicle travel direction is opposite to the vehicle travel direction in the driving lane on a road where driving lanes are formed.

The ECU 21 starts the oncoming vehicle warning process when at least one of the "route crossing warning condition", "first advance warning condition", and "second advance warning condition" is met. For convenience, each of the "route crossing warning condition", "first advance warning condition", and "second advance warning condition" is also referred to as a "specific condition". For convenience, the right in a left-hand traffic area (i.e., the turning direction in which the vehicle crosses with an oncoming vehicle going straight when attempting to turn) is also referred to as a "specific direction". In a right-hand traffic area, the right is the specific direction.

<<Route crossing notification conditions>>
The route crossing notification condition is met when all of the following conditions (A1) to (A4) are met.
Condition (A1): The right indicator 43R is activated (flashing).
Condition (A2): An oncoming vehicle is present.
Condition (A3): The "host vehicle predicted route" of the vehicle 10 and the "oncoming vehicle predicted route" of the oncoming vehicle intersect with each other.
Condition (A4): The intersection arrival time Tc is equal to or shorter than a predetermined first threshold time Tth1 (i.e., Tc≦Tth1).

Each of conditions (A1) to (A4) will be described with reference to FIG. 3. In FIG. 3, the current position of vehicle 10 is indicated by vehicle position 10a. In this example, the driver is attempting to turn vehicle 10 right at an intersection. Specifically, the driver is attempting to move vehicle 10 from vehicle position 10a to vehicle position 10b, vehicle position 10c, and then to vehicle position 10d. The dashed line Le1 indicates the driver's intended travel path of vehicle 10 (specifically, the path of movement of the front center of vehicle 10).

As described below, the presence of the other vehicle 61 is notified to the driver of the vehicle 10 by the oncoming vehicle notification process before the vehicle 10 reaches the vehicle position 10d. Therefore, there is a high possibility that the driver will stop the vehicle 10 when the vehicle 10 is located near the vehicle position 10c.

While vehicle 10 is traveling in the section from vehicle position 10a to vehicle position 10b, steering angle θs is 0°. After vehicle 10 passes vehicle position 10b, steering angle θs begins to increase, and vehicle 10 turns to the right. Thereafter, steering angle θs begins to decrease, and when vehicle 10 reaches vehicle position 10d, steering angle θs returns to 0°.

The driver starts the operation (flashing) of the right indicator 43R when the vehicle 10 reaches the vehicle position 10a. Therefore, condition (A1) is satisfied when the vehicle 10 reaches the vehicle position 10a.

The other vehicle 61 shown in FIG. 3 is a other vehicle detected based on a forward image (i.e., a camera-detected target whose target type is "vehicle"). The position of the other vehicle 61 when the vehicle 10 is at vehicle position 10a is indicated by other vehicle position 61a. The position of the other vehicle 61 when the vehicle 10 is at vehicle position 10b is indicated by other vehicle position 61b. The position of the other vehicle 61 when the vehicle 10 is at vehicle position 10c is indicated by other vehicle position 61c.

<<<<Conditions for determining an oncoming vehicle>>>
In this embodiment, the oncoming vehicle is a camera-detected object that satisfies all of the following conditions (a) to (e). That is, if all of the conditions (a) to (e) are satisfied, the condition (A2) is satisfied. That is, if all of the conditions (a) to (e) are satisfied, it is determined that an oncoming vehicle is present.
Condition (a): A camera-detected target is present, and the type of the target is a "vehicle."
Condition (b): The vertical position Dy of the target detected by the camera is a positive value (i.e., Dy>0).
Condition (c): The longitudinal relative velocity Vy of the target detected by the camera is a negative value (i.e., Vy<0).
Condition (d): The target travel speed Vc of the camera-detected target is equal to or greater than a predetermined threshold speed Vcth of other vehicles (i.e., Vc≧Vcth).
Condition (e): The camera-detected object is expected to pass to the right of the current position of the vehicle 10.

The other vehicle 61 is a camera-detected object whose object type is "vehicle," so condition (a) is met.

As can be seen from other vehicle positions 61a to 61c, when vehicle 10 is traveling in the section from vehicle position 10a to vehicle position 10c, other vehicle 61 is in front of vehicle 10. In other words, since the longitudinal position Dy of other vehicle 61 is a positive value during the period when vehicle 10 is traveling in this section, condition (b) is satisfied.

In addition, while vehicle 10 is traveling in the section from vehicle position 10a to vehicle position 10c, other vehicle 61 is approaching vehicle 10 in the fore-and-aft direction of vehicle 10. In other words, since the longitudinal relative speed Vy of other vehicle 61 is a negative value while vehicle 10 is traveling in this section, condition (c) is satisfied.

The other vehicle threshold speed Vcth related to condition (d) is preset to be approximately equal to the lower limit of the typical driving speed that the vehicle can assume when traveling straight through the intersection. Since the other vehicle 61 is traveling straight through the intersection, its target driving speed Vc is greater than the other vehicle threshold speed Vcth. Therefore, condition (d) is satisfied.

Next, condition (e) will be described. If the "anticipated path of the oncoming vehicle" of the camera-detected target intersects with the "right half line" of the vehicle 10, the ECU 21 determines that condition (e) is met. The anticipatory path of the oncoming vehicle is obtained based on the position (i.e., lateral position Dx and longitudinal position Dy) and speed (i.e., lateral relative velocity Vx and longitudinal relative velocity Vy) of the camera-detected target, on the assumption that the speed will be maintained unchanged.

In FIG. 3, the predicted oncoming vehicle route of the other vehicle 61 at the other vehicle position 61a is indicated by the dashed line Ls1. In this example, the other vehicle 61 is traveling straight. Therefore, the predicted oncoming vehicle route of the other vehicle 61 at the other vehicle position 61b is indicated by the section of the dashed line Ls1 in FIG. 3 that is lower on the paper than the other vehicle position 61b. Similarly, the predicted oncoming vehicle route of the other vehicle 61 at the other vehicle position 61c is indicated by the section of the dashed line Ls1 in FIG. 3 that is lower on the paper than the other vehicle position 61c.

The right half line of the vehicle 10 is a half line that extends rightward from the center of the front end of the vehicle 10 (i.e., the origin of the X-Y coordinate system) in the vehicle width direction (i.e., the X-axis direction) of the vehicle 10. In FIG. 3, the right half line of the vehicle 10 at vehicle position 10a is indicated by the dashed line Lra. The right half line of the vehicle 10 at vehicle position 10b is indicated by the dashed line Lrb. The right half line of the vehicle 10 at vehicle position 10c is indicated by the dashed line Lrc.

The dashed line Ls1 (i.e., the predicted path of the oncoming vehicle of the other vehicle 61) and the dashed line Lra intersect with each other at point Pra. Similarly, the dashed line Ls1 and the dashed line Lrb intersect with each other at point Prb, and the dashed line Ls1 and the dashed line Lrc intersect with each other at point Prc. Therefore, during the period when the vehicle 10 travels from vehicle position 10a to vehicle position 10c, condition (e) is satisfied.

Therefore, while vehicle 10 is traveling in the section from vehicle position 10a to vehicle position 10c, other vehicle 61 satisfies all of conditions (a) through (e), and thus condition (A2) is met.

Next, condition (A3) will be described. The predicted vehicle route is the predicted driving route of the vehicle 10, and is obtained based on the steering angle θs at the current time, on the assumption that the steering angle θs will be maintained unchanged. When the vehicle 10 is at the vehicle position 10a, the predicted vehicle route is indicated by the dashed line Lh1. As described above, the steering angle θs at this time is 0°, so the dashed line Lh1 is a straight line. The predicted vehicle route of the vehicle 10 at the vehicle position 10b is indicated by the section of the dashed line Lh1 in FIG. 3 that is above the vehicle position 10b on the paper.

As can be seen from FIG. 3, the predicted route of the vehicle when the vehicle 10 is at the vehicle position 10a (i.e., the dashed line Lh1) does not intersect with the predicted route of the oncoming vehicle of the other vehicle 61 (specifically, the other vehicle 61 at the other vehicle position 61a) (i.e., the dashed line Ls1). Similarly, the predicted route of the vehicle when the vehicle 10 is at the vehicle position 10b (i.e., the dashed line Lh1) does not intersect with the predicted route of the oncoming vehicle of the other vehicle 61 (specifically, the other vehicle 61 at the other vehicle position 61b) (i.e., the dashed line Ls1). Therefore, during the period when the vehicle 10 is traveling in the section from the vehicle position 10a to the vehicle position 10b, the condition (A3) is not satisfied. Therefore, during this period, the route intersection notification condition is not satisfied.

On the other hand, the predicted path of the vehicle 10 when the vehicle 10 reaches the vehicle position 10c is indicated by the dashed line Lh2. At this point, the steering angle θs is a positive value (steering angle θs>0), so as can be seen from the dashed line Lh2, the predicted driving path of the vehicle 10 curves to the right.

The dashed lines Lh2 and Ls1 intersect at point Ps2. Therefore, when the vehicle 10 is at vehicle position 10c, condition (A3) is satisfied.

Furthermore, condition (A4) will be described. The intersection arrival time Tc is the time it takes for the vehicle 10 to reach the intersection (point Ps2 in this example) between the predicted route of the vehicle and the predicted route of the oncoming vehicle. The ECU 21 obtains (calculates) the intersection arrival time Tc by dividing the distance (path) from the vehicle 10 to the intersection between the predicted route of the vehicle and the predicted route of the oncoming vehicle by the vehicle speed Vs. In this example, the intersection arrival time Tc becomes equal to the first threshold time Tth1 when the vehicle 10 reaches the vehicle position 10c. That is, the condition (A4) is met when the vehicle 10 reaches the vehicle position 10c.

Therefore, when the vehicle 10 reaches the vehicle position 10c, all of the conditions (A1) to (A4) are met, and thus the route crossing notification condition is met.

<<First advance notification condition>>
The first advance warning condition is satisfied when the above-mentioned "condition (A1) and condition (A2)" and the following condition (B3a) are all satisfied. That is, the first advance warning condition is satisfied when the following conditions are all satisfied.
Condition (A1): The right indicator 43R is activated (flashing).
Condition (A2): An oncoming vehicle is present.
Condition (B3a): The right lane marking is not included in the "right-turn passing area of the vehicle 10" described later. For convenience, the condition (B3a) is also referred to as the "specific area condition." The condition (B3a) is satisfied when it is predicted (estimated) that the host vehicle is highly likely to start turning in a specific direction.

The "right-turn passing area" of the vehicle 10 is an area diagonally forward to the right near the vehicle 10, and more specifically, is a pentagonal area with vertices at the center of the front end of the vehicle 10 (origin O), points Pa, Pb, Pc, and Pd. The X-Y coordinate values of points Pa, Pb, Pc, and Pd are Pa (0, Dy1), Pb (Dx1, Dy1), Pc (Dx1, Dy2), and Pd (Wd/2, 0), respectively. The right-turn passing area is an area that includes a part of the area through which the vehicle 10 passes when turning right (turning in a specific direction), and is predetermined for the vehicle 10, and is also referred to as the "specific area" for convenience.

Each of the distances Dx1, Dy1, and Dy2 is a fixed value that is determined in advance so that the right-turn passing area is "an area through which the vehicle 10 is likely to pass when the vehicle 10 turns right (i.e., when the vehicle 10 turns to the right)." The vehicle width Wd used to define the point Pd is the length of the vehicle 10 in the vehicle width direction (see FIG. 1). Note that Dy1>Dy2>0 and Dx1>Wd/2>0.

For example, when the vehicle 10 is at vehicle position 10a, the right-turn passing area is indicated by area Rpa. This area Rpa includes the right-hand lane marking Lt1. Therefore, at this point in time, condition (B3a) is not satisfied.

The right-turn passing area when the vehicle 10 is at vehicle position 10b is indicated by area Rpb, and the right-turn passing area when the vehicle 10 is at vehicle position 10c is indicated by area Rpc. Neither of these "areas Rpb and area Rpc" includes the lane line (right lane line) Lt1. That is, after the vehicle 10 reaches vehicle position 10b, the lane line (right lane line) Lt1 is no longer included in the right-turn passing area. Therefore, condition (B3a) is met after the vehicle 10 reaches vehicle position 10b. That is, in the example shown in FIG. 3, conditions (A1), (A2), and (B3a) are met when the vehicle 10 reaches vehicle position 10b, and thus the first advance warning condition is met.

In this way, the first advance warning condition is met at the time when the vehicle 10 reaches the vehicle position 10b, which is earlier than the time when the route crossing warning condition is met (the time when the vehicle 10 reaches the vehicle position 10c). Therefore, in this example, the oncoming vehicle warning process is started earlier.

<<Second advance notification condition>>
The second advance warning condition is satisfied when the above-mentioned "condition (A1) and condition (A2)" and the following "condition (B3b) and condition (B4)" are all satisfied. That is, the second advance warning condition is satisfied when the following conditions are all satisfied.
Condition (A1): The right indicator 43R is activated (flashing).
Condition (A2): An oncoming vehicle is present.
Condition (B3b): The right-turn passing area of the vehicle 10 includes a right lane marking.
Condition (B4): The vehicle speed Vs is smaller than a predetermined first threshold speed Vth1 (i.e., Vs<Vth1). The first threshold speed Vth1 is preset so as to be approximately equal to an upper limit (upper limit immediately before a right or left turn) of general driving speeds that the vehicle can attain when the vehicle starts to turn right (or left).
In addition, when both the condition (B3b) and the condition (B4) are satisfied, it is also expressed as the satisfaction of a “turn waiting condition.” The turn waiting condition is a condition that is satisfied when it is predicted (estimated) that there is a high possibility that the host vehicle will start turning in a specific direction.

Furthermore, the second advance warning condition will be described with reference to FIG. 4. In the example shown in FIG. 4, the current position of the vehicle 10 is indicated by vehicle position 10e. In this example, the driver is attempting to have the vehicle 10 cross the oncoming lane and enter the parking position Rs. Specifically, the driver is attempting to have the vehicle 10 reach vehicle position 10i from vehicle position 10e via vehicle positions 10f to 10h. The dashed line Le2 indicates the driving route of the vehicle 10 that is intended by the driver. The success or failure of each of the route crossing warning condition, the first advance warning condition, and the second advance warning condition in this case will be described in order.

The driver starts the operation (flashing) of the right indicator 43R when the vehicle 10 reaches the vehicle position 10f. Therefore, when the vehicle 10 reaches the vehicle position 10f, the condition (A1) is satisfied.

The other vehicle 62 shown in FIG. 4 is a other vehicle detected based on a forward image (i.e., a camera-detected target whose target type is "vehicle"). Therefore, the other vehicle 62 satisfies the above-mentioned condition (a).

The position of the other vehicle 62 when the vehicle 10 is at vehicle position 10e is indicated by other vehicle position 62e. The position of the other vehicle 62 when the vehicle 10 is at vehicle position 10f is indicated by other vehicle position 62f. The position of the other vehicle 62 when the vehicle 10 is at vehicle position 10g is indicated by other vehicle position 62g.

The predicted oncoming vehicle path of the other vehicle 62 located at the other vehicle position 62e is indicated by the dashed line Ls2. In this example, the target travel speed Vc of the other vehicle 62 is greater than the other vehicle threshold speed Vcth. Therefore, the other vehicle 62 satisfies condition (b).

In this example, the other vehicle 62 is traveling straight. Therefore, the predicted oncoming vehicle route of the other vehicle 62 at the other vehicle position 62f is indicated by the section located below the other vehicle position 62f on the paper of the dashed line Ls2 in FIG. 4. The predicted oncoming vehicle route of the other vehicle 62 at the other vehicle position 62g is indicated by the section located below the other vehicle position 62g on the paper of the dashed line Ls2 in FIG. 4.

As can be seen from FIG. 4, during the period when the vehicle 10 is traveling from vehicle position 10e to vehicle position 10g, the longitudinal position Dy of the other vehicle 62 is a positive value and the longitudinal relative velocity Vy is a negative value (i.e., Dy>0 and Vy<0). Therefore, during this period, the other vehicle 62 satisfies conditions (b) and (c).

The right half line of the vehicle 10 at vehicle position 10e is indicated by the dashed line Lre. The right half line of the vehicle 10 at vehicle position 10f is indicated by the dashed line Lrf. The right half line of the vehicle 10 at vehicle position 10g is indicated by the dashed line Lrg.

The dashed line Ls2 (i.e., the predicted path of the oncoming vehicle of the other vehicle 62) and the dashed line Lre intersect with each other at point Pre. Similarly, the dashed line Ls2 and the dashed line Lrf intersect with each other at point Prf, and the dashed line Ls2 and the dashed line Lrg intersect with each other at point Prg. Therefore, during the period when the vehicle 10 travels from vehicle position 10e to vehicle position 10g, condition (e) is satisfied.

Therefore, while the vehicle 10 is traveling in the section from vehicle position 10e to vehicle position 10g, the other vehicle 62 satisfies all of conditions (a) to (e), and condition (A2) is met. In other words, the other vehicle 62 is determined to be an oncoming vehicle.

The predicted path of the vehicle 10 when the vehicle 10 is at the vehicle position 10f is indicated by the dashed line Lh3. The dashed line Ls2 (i.e., the predicted path of the oncoming vehicle of the other vehicle 62) and the dashed line Lh3 do not intersect with each other. In other words, at this point in time, the condition (A3) is not satisfied.

Then, the predicted vehicle path when the vehicle 10 is at the vehicle position 10g is indicated by the dashed line Lh4. The dashed lines Ls2 and Lh4 intersect at the point Ps4. Therefore, at this point, the condition (A3) is satisfied.

In addition, the intersection arrival time Tc when the vehicle 10 is at the vehicle position 10g is equal to the first threshold time Tth1. Therefore, in other words, the condition (A4) is satisfied when the vehicle 10 reaches the vehicle position 10g.

Therefore, when the vehicle 10 reaches the vehicle position 10g, all of the conditions (A1) to (A4) are met, and thus the route crossing notification condition is met.

Next, we will explain whether the first advance warning condition is met. The right-turn passing area of the vehicle 10 at vehicle position 10e is indicated by area Rpe. Similarly, the right-turn passing area of the vehicle 10 at vehicle position 10f is indicated by area Rpf. The right-turn passing area of the vehicle 10 at vehicle position 10g is indicated by area Rpg.

As can be seen from FIG. 4, each of the regions Rpe, Rpf, and Rpg includes the right-hand demarcation line Lt2. Therefore, during the period when the vehicle 10 is traveling in the section from vehicle position 10e to vehicle position 10g, condition (B3a) is not satisfied. Therefore, the first advance warning condition is not satisfied during this period.

Furthermore, the satisfaction of the second advance warning condition will be explained. As described above, each of the regions Rpe, Rpf, and Rpg includes the right-hand demarcation line Lt2. Therefore, the condition (B3b) is satisfied during the period when the vehicle 10 is traveling in the section from vehicle position 10e to vehicle position 10g.

As described above, the first threshold speed Vth1 is set to the upper limit immediately before a right or left turn, and the driver of the vehicle 10 intends to make a right turn, so the vehicle speed Vs is smaller than the first threshold speed Vth1 during the period when the vehicle 10 is traveling in the section from vehicle position 10e to vehicle position 10g. Therefore, condition (B4) is satisfied during this period.

As described above, the driver activates the right indicator 43R when the vehicle 10 reaches vehicle position 10f, so condition (A1) is met at this point. Therefore, the second advance warning condition is met when the vehicle 10 reaches vehicle position 10f.

In this way, the second advance warning condition is met at the time when the vehicle 10 reaches the vehicle position 10f, which is earlier than the time when the route crossing warning condition is met (the time when the vehicle 10 reaches the vehicle position 10g). Therefore, in this example, the oncoming vehicle warning process is started earlier.

Next, the reason why the second advance warning condition includes condition (B4) will be explained with reference to FIG. 5. In FIG. 5, the current position of vehicle 10 is indicated by vehicle position 10j. The driver is attempting to change lanes of vehicle 10 from the driving lane to "a lane adjacent to the driving lane to the right of vehicle 10 (a lane whose set vehicle travel direction is the same as the vehicle travel direction in the driving lane, and which is generally also referred to as an "overtaking lane" or "adjacent lane").)" Specifically, the driver is attempting to move vehicle 10 from vehicle position 10j to vehicle position 10k and then to vehicle position 10m. The dashed line Le3 indicates the driver's intended travel route of vehicle 10.

The driver starts the operation of the right indicator 43R when the vehicle 10 reaches the vehicle position 10k. Therefore, when the vehicle 10 reaches the vehicle position 10k, the condition (A1) is satisfied. The driver stops the operation of the right indicator 43R when the vehicle 10 reaches the vehicle position 10m (i.e., when the lane change is completed).

The other vehicle 63 shown in FIG. 5 is a other vehicle detected based on the forward image (i.e., a camera-detected target whose target type is "vehicle"). The position of the other vehicle 63 when the vehicle 10 is at vehicle position 10j is indicated by other vehicle position 63j. The position of the other vehicle 63 when the vehicle 10 is at vehicle position 10k is indicated by other vehicle position 63k. The position of the other vehicle 63 when the vehicle 10 is at vehicle position 10m is indicated by other vehicle position 63m.

Although a detailed description is omitted, during the period when vehicle 10 is traveling in the section from vehicle position 10j to vehicle position 10m, other vehicle 63 satisfies the requirements for an oncoming vehicle (i.e., conditions (a) to (e)). Therefore, condition (A2) is met. On the other hand, during the period when vehicle 10 is traveling in the section from vehicle position 10j to vehicle position 10m, neither condition (A3) nor condition (A4) is met. In other words, the route crossing notification condition is not met during this period.

The right-turn passing area of the vehicle 10 at vehicle position 10j is indicated by area Rpj. Similarly, the right-turn passing area of the vehicle 10 at vehicle position 10k is indicated by area Rpk. The right-turn passing area of the vehicle 10 at vehicle position 10m is indicated by area Rpm.

The right-hand demarcation line of the driving lane of vehicle 10 at vehicle position 10j is demarcation line Lt3. The right-hand demarcation line of the adjacent lane is demarcation line Lt4. As can be seen from FIG. 5, each of regions Rpj and Rpk includes demarcation line Lt3. In addition, region Rpm includes demarcation line Lt4. Therefore, during the period when vehicle 10 is traveling in the section from vehicle position 10j to vehicle position 10m, condition (B3a) is not met. In other words, the first advance warning condition is not met during this period.

On the other hand, condition (B3b) is satisfied during the period when vehicle 10 is traveling in the section from vehicle position 10j to vehicle position 10m. In addition, vehicle speed Vs is greater than first threshold speed Vth1 during the period when vehicle 10 is traveling in the section from vehicle position 10j to vehicle position 10m. Therefore, condition (B4) is not satisfied during this period. That is, when vehicle 10 changes lanes as shown in FIG. 5, vehicle speed Vs is more likely to be greater than when vehicle 10 turns right as shown in FIG. 4. In this case, vehicle speed Vs is greater than first threshold speed Vth1, and therefore condition (B4) is not satisfied. That is, the second advance warning condition is not satisfied during this period.

Therefore, during the period when the vehicle 10 is traveling in the section from vehicle position 10j to vehicle position 10m, none of the route crossing notification condition, the first advance notification condition, and the second advance notification condition are met, and therefore the oncoming vehicle notification process is not executed. In other words, for example, even if the right indicator 43R is activated and an oncoming vehicle is present when changing lanes (i.e., even if conditions (A1), (A2), and (B3b) are met), condition (B4) is not met unless the driver reduces the vehicle speed Vs to turn the vehicle 10 right. Therefore, the second advance notification condition is not met when changing lanes, and therefore the oncoming vehicle notification process is not executed.

(Specific operation)
Next, a specific operation of the ECU 21 will be described. The CPU 31 (hereinafter, simply referred to as the "CPU") of the ECU 21 executes an "oncoming vehicle warning determination processing routine" shown in the flowchart of FIG.

Therefore, at an appropriate timing, the CPU starts processing from step 600 in FIG. 6 and proceeds to step 605 to determine whether the current state is a state in which the oncoming vehicle notification process (hereinafter also simply referred to as "notification process") is not being performed. In other words, the CPU determines whether the "notification operation using the display 46 and speaker 47" to notify the driver of the presence of an oncoming vehicle is currently being performed.

(Case A)
It is assumed that this routine is executed for the first time after the notification process is not being executed and the route crossing notification condition is satisfied.

According to this assumption, since the notification process is not currently being executed, the CPU judges "Yes" in step 605 and proceeds to step 610 to determine whether the right indicator 43R is in an activated state (is activated or not). In other words, the CPU determines whether the above-mentioned condition (A1) is satisfied.

According to the above assumption, the right indicator 43R is activated. Therefore, the CPU judges "Yes" in step 610 and proceeds to step 615 to determine whether an oncoming vehicle is present. In other words, the CPU determines whether condition (A2) is satisfied.

According to the above assumption, an oncoming vehicle is present. Therefore, the CPU judges "Yes" in step 615 and proceeds to step 620 to determine whether the predicted path of the host vehicle and the predicted path of the oncoming vehicle intersect with each other. In other words, the CPU determines whether condition (A3) is satisfied.

According to the above assumption, the predicted path of the vehicle and the predicted path of the oncoming vehicle intersect with each other. Therefore, the CPU judges "Yes" in step 620 and proceeds to step 625 to determine whether the intersection arrival time Tc is equal to or less than the first threshold time Tth1. In other words, the CPU judges whether the condition (A4) is satisfied.

According to the above assumption, the intersection arrival time Tc is less than or equal to the first threshold time Tth1. Therefore, the CPU judges "Yes" in step 625 and proceeds to step 630 to start the notification process.

Specifically, the CPU displays a symbol (oncoming vehicle warning symbol) on the display 46 indicating that the vehicle 10 is highly likely to collide with an oncoming vehicle. In addition, the CPU causes the speaker 47 to emit a warning sound (oncoming vehicle warning sound) indicating that the vehicle 10 is highly likely to collide with an oncoming vehicle. Next, the CPU proceeds to step 695 and ends the processing of this routine.

(Case B)
It is assumed that this routine is executed for the first time after the notification process is not executed and the first advance notification condition is satisfied. For example, in the example shown in FIG. 3, this assumption applies when this routine is executed for the first time after the vehicle 10 reaches the vehicle position 10b.

In this case, since both condition (A1) and condition (A2) are satisfied, the CPU judges "Yes" in each of steps 610 and 615 and proceeds to step 620. According to the above assumption, the route crossing notification condition is not satisfied (i.e., condition (A3) is not satisfied). Therefore, the CPU judges "No" in step 620 and proceeds to step 645 to determine whether the current state is a state in which "the right-turn passing area does not include a right-hand lane line." That is, the CPU judges whether condition (B3a) is satisfied (in other words, whether condition (B3b) is not satisfied).

According to the above assumption, the first advance notification condition is met (i.e., condition (B3a) is met), so the CPU judges "Yes" in step 645 and proceeds to step 630 to start the notification process.

(Case C)
It is assumed that this routine is executed for the first time after the notification process is not executed and the second advance notification condition is satisfied. For example, in the example shown in FIG. 4, this assumption applies to the case where this routine is executed for the first time after the vehicle 10 reaches the vehicle position 10f.

In this case, both conditions (A1) and (A2) are satisfied, while neither conditions (A3) nor (B3a) are satisfied. Therefore, the CPU judges "Yes" at each of steps 610 and 615, and then judges "No" at each of steps 620 and 645, and proceeds to step 650.

In step 650, the CPU determines whether the vehicle speed Vs is less than the first threshold speed Vth1. That is, the CPU determines whether the condition (B4) is satisfied. According to the above-mentioned assumption, the vehicle speed Vs is less than the first threshold speed Vth1, so the CPU determines "Yes" in step 650 and proceeds to step 630 to start the notification process.

(Case D)
Next, it is assumed that the notification process is being executed and the "notification end condition" is not satisfied. The notification end condition is a condition that is satisfied when the notification process should be ended, and will be described later.

In this case, since the notification process has already been executed, the CPU judges "No" at step 605 and proceeds to step 635 to judge whether the notification end condition is satisfied. According to the above assumption, since the notification end condition is not satisfied, the CPU judges "No" at step 635 and proceeds directly to step 695. In other words, after the notification process is started, the notification process continues for the period until the notification end condition is satisfied.

(Case E)
It is assumed that this routine is executed for the first time after the notification process is executed and the notification end condition is satisfied.

<<Conditions for ending notification>>
The notification end condition in this embodiment is a condition that is met when at least one of the following conditions (C1) to (C3) is met.
Condition (C1): The operation of the right indicator 43R has ended (the state of the right indicator 43R has changed from an activated state to a non-activated state).
Condition (C2): There is no longer an oncoming vehicle.
Condition (C3): The vehicle 10 stops (the vehicle speed Vs changes to "0").

For example, if another vehicle (i.e., an oncoming vehicle) decelerates and the target traveling speed Vc becomes smaller than the other vehicle threshold speed Vcth, condition (d) is no longer satisfied, and the other vehicle is no longer an oncoming vehicle. In this case, condition (C2) is satisfied, and the notification termination condition is satisfied. In addition, if the driver notices the presence of an oncoming vehicle and stops the vehicle 10 (i.e., when the vehicle speed Vs becomes "0"), condition (C3) is satisfied, and the notification termination condition is satisfied.

According to the above assumption, the notification termination condition is met, so the CPU judges "Yes" in step 635 and proceeds to step 640 to terminate the notification process. Specifically, the CPU terminates the display of the above-mentioned oncoming vehicle warning symbol on the display 46. In addition, the CPU terminates the generation of the oncoming vehicle warning sound by the speaker 47. The CPU then proceeds directly to step 695.

(Other cases)
If the notification process is not being performed and the condition (A1) is not satisfied, the CPU judges "No" in step 610 and proceeds directly to step 695. If the notification process is not being performed and the condition (A1) is satisfied but the condition (A2) is not satisfied, the CPU judges "No" in step 615 and proceeds directly to step 695. If the notification process is not being performed and the conditions (A1) to (A3) are satisfied but the condition (A4) is not satisfied, the CPU judges "No" in step 625 and proceeds directly to step 695. If the notification process is not being performed and the conditions (A1), (A2) and (B3b) are satisfied but the condition (B4) is not satisfied, the CPU judges "No" in step 650 and proceeds directly to step 695.

As described above, the notification device equipped with the ECU 21 executes the oncoming vehicle notification process at the timing when the first advance notification condition or the second advance notification condition is satisfied, even if the predicted route of the vehicle itself, which is acquired based on the steering angle θs of the vehicle 10, and the predicted route of the oncoming vehicle do not intersect with each other (i.e., even if the route intersection notification condition is not satisfied). That is, according to the notification device, it is possible to start the oncoming vehicle notification process early. In addition, as shown in the example of FIG. 5, when the vehicle 10 is changing lanes to the right (i.e., when the vehicle 10 is not about to turn right), the oncoming vehicle notification process is not executed. That is, the oncoming vehicle notification process is not operated unnecessarily.

(First Modification of the Notification Device)
Next, a first modified example (first modified device) of the present notification device will be described. The above-mentioned notification device executes the oncoming vehicle notification process when at least one of the route crossing notification condition, the first advance notification condition, and the second advance notification condition is satisfied. In contrast, the first modified device executes the oncoming vehicle notification process when at least one of the route crossing notification condition and the "third advance notification condition" is satisfied. The third advance notification condition is a condition whose success or failure is determined based on the state of the "preceding vehicle", which is another vehicle traveling in a position immediately before the vehicle 10. The difference will be described below.

<<Third advance notification condition>>
The third advance warning condition is satisfied when the above-mentioned conditions (A1) and (A2) and the following condition (D3) are all satisfied. That is, the third advance warning condition is satisfied when the following conditions are all satisfied:
Condition (A1): The right indicator 43R is activated (flashing).
Condition (A2): An oncoming vehicle is present.
Condition (D3): The target travel speed Vc of the preceding vehicle is greater than a predetermined second threshold speed Vth2 (i.e., Vc>Vth2). The second threshold speed Vth2 is preset so as to be approximately equal to the lower limit of a range of general travel speeds when a vehicle turns right. For convenience, the second threshold speed Vth2 is also referred to as the preceding vehicle turning threshold speed. When the target travel speed Vc of the preceding vehicle becomes greater than the second threshold speed Vth2 from a value equal to or less than the second threshold speed Vth2, it can be determined that the preceding vehicle has started to turn right (turn in a specific direction). Condition (D3) is a condition that is met when it is predicted (estimated) that there is a high possibility that the host vehicle will start turning in a specific direction.

The third advance notification condition will be explained with reference to FIG. 7. In FIG. 7, the current position of vehicle 10 is indicated by vehicle position 10n. In this example, the driver is attempting to turn vehicle 10 right at an intersection. Specifically, the driver is attempting to drive vehicle 10 from vehicle position 10n through vehicle position 10o to vehicle position 10p. The dashed line Le4 indicates the driving route of vehicle 10 that is intended by the driver.

The predicted vehicle route when the vehicle 10 is at vehicle position 10n is indicated by dashed line Lh5. The predicted vehicle route when the vehicle 10 is at vehicle position 10o is indicated by the section of dashed line Lh5 in FIG. 7 that is above vehicle position 10n.

The other vehicle 64 shown in FIG. 7 is a other vehicle detected based on the forward image (i.e., a camera-detected target whose target type is "vehicle"). The position of the other vehicle 64 when the vehicle 10 is at vehicle position 10n is indicated by other vehicle position 64n. The position of the other vehicle 62 when the vehicle 10 is at vehicle position 10o is indicated by other vehicle position 64o.

The driver starts the operation (flashing) of the right indicator 43R when the vehicle 10 reaches the vehicle position 10o. Therefore, when the vehicle 10 reaches the vehicle position 10o, the condition (A1) is satisfied.

Although a detailed description is omitted, at least during the "period when vehicle 10 is traveling in the section from vehicle position 10n to vehicle position 10o," other vehicle 64 meets the requirements of an oncoming vehicle, and thus condition (A2) is met. On the other hand, conditions (A3) and (A4) are met after vehicle 10 passes vehicle position 10o. In other words, neither condition (A3) nor condition (A4) is met at the time when vehicle 10 reaches vehicle position 10o. In this example, conditions (A3) and (A4) are met at the time when vehicle 10 reaches vehicle position 10o, and as a result, the route crossing notification condition is met.

The other vehicle 65 shown in FIG. 7 is a camera-detected target detected based on the forward image. The position of the other vehicle 65 when the vehicle 10 is at vehicle position 10n is indicated by other vehicle position 65n. The position of the other vehicle 65 when the vehicle 10 is at vehicle position 10o is indicated by other vehicle position 65o.

The vehicle control ECU 22 (hereinafter also simply referred to as "ECU 22") associated with the first transformation device determines that the other vehicle 65 is a preceding vehicle during the period when the vehicle 10 is traveling in the section from vehicle position 10n to vehicle position 10o.

<<<<Conditions for determining a preceding vehicle>>>>
More specifically, the preceding vehicle is a camera-detected object that satisfies all of the above-mentioned conditions (a) and (b) as well as the following conditions (f) and (g). That is, if all of conditions (a), (b), (f), and (g) are satisfied, it is determined that a preceding vehicle is present.
Condition (a): A camera-detected target is present, and the type of the target is a "vehicle."
Condition (b): The vertical position Dy of the target detected by the camera is a positive value (i.e., Dy>0).
Condition (f): The vertical position Dy of the target detected by the camera is smaller than a predetermined distance Dy3 (i.e., Dy<Dy3).
Condition (g): The left end position of the camera-detected target is on the left of the predicted vehicle path and the right end position is on the right of the predicted vehicle path.

The other vehicle 65 is a camera-detected object whose object type is "vehicle," so condition (a) is met. During the period when the vehicle 10 travels the section from vehicle position 10n to vehicle position 10o, the other vehicle 65 is in front of the vehicle 10, so the longitudinal position Dy is a positive value. Therefore, during this period, condition (b) is met.

As can be seen from FIG. 7, when the vehicle 10 is at the vehicle position 10n, the longitudinal position Dy of the other vehicle 65 is the distance Da, which is smaller than the distance Dy3 (i.e., Da<Dy3). Therefore, the condition (f) is satisfied.

At this point, the left end position of the other vehicle 65 is point Pe, and the right end position is point Pf. Point Pe (i.e., the left end position) is to the left of dashed line Lh5 (i.e., the predicted path of the vehicle), and point Pf (i.e., the right end position) is to the right of dashed line Lh5. Therefore, condition (g) is satisfied.

In this example, during the period when vehicle 10 travels in the section from vehicle position 10n to vehicle position 10o, both conditions (f) and (g) are met. That is, during the period when vehicle 10 travels in the section from vehicle position 10n to vehicle position 10o, conditions (a), (b), (f), and (g) are all met. Therefore, during this period, other vehicle 65 meets the requirements for a preceding vehicle.

In addition, in this example, the target travel speed Vc of the other vehicle 65 (i.e., the preceding vehicle) during the period when the vehicle 10 travels in the section from vehicle position 10n to vehicle position 10o is greater than the second threshold speed Vth2. That is, condition (D3) is satisfied during the period when the vehicle 10 travels in the section from vehicle position 10n to vehicle position 10o.

For example, if the driver of the other vehicle 65 attempts to turn right at an intersection without noticing the presence of an oncoming vehicle (in this example, the other vehicle 64), the target traveling speed Vc of the other vehicle 65 may be greater than the second threshold speed Vth2. Alternatively, if the driver of the other vehicle 65 attempts to turn the other vehicle 65 right before the other vehicle 64 reaches the intersection, the target traveling speed Vc of the other vehicle 65 may be greater than the second threshold speed Vth2. In these cases, the driver of the vehicle 10 may think that there is no oncoming vehicle and may attempt to start turning the vehicle 10 right following the other vehicle 65. In order to avoid such a situation from occurring, when condition (D3) is met in addition to condition (A1) and condition (A2), the oncoming vehicle notification process is executed.

Therefore, when the driver starts to operate the right indicator 43R when the vehicle 10 reaches the vehicle position 10o, the condition (A1) is met, and the third advance warning condition is met (before the route crossing warning condition is met). In other words, the oncoming vehicle warning process is started when the vehicle 10 reaches the vehicle position 10o.

(Specific Operation of the First Deformation Device)
The CPU 31 (hereinafter, also simply referred to as "CPU") of the ECU 22 associated with the first modification device executes an "oncoming vehicle notification determination processing routine" shown by a flowchart in Fig. 8 every time a predetermined time has elapsed, instead of the "oncoming vehicle notification determination processing routine" shown in Fig. 6. Note that steps shown in each of the flowcharts described below, in which the same processing as the steps shown in the flowchart in Fig. 6 is executed, are assigned the same step symbols as in Fig. 6.

Therefore, at an appropriate timing, the CPU starts processing from step 800 in FIG. 8 and executes processing of steps 605 and after. If the CPU determines "No" in step 620 (i.e., condition (A1) and condition (A2) are satisfied, but condition (A3) is not satisfied), it proceeds to step 820.

In step 820, the CPU determines whether a preceding vehicle is present, and if a preceding vehicle is present, determines whether the target traveling speed Vc of the preceding vehicle is greater than a second threshold speed (preceding vehicle turning threshold speed) Vth2. In other words, the CPU determines whether condition (D3) is satisfied.

If the target travel speed Vc of the preceding vehicle is greater than the second threshold speed Vth2 (i.e., if condition (D3) is met), the CPU judges "Yes" in step 820 and proceeds to step 630 to start the notification process. In other words, in this case, the third preceding notification condition is met. Next, the CPU proceeds to step 895 and ends the processing of this routine.

On the other hand, if the target travel speed Vc of the preceding vehicle is equal to or less than the second threshold speed Vth2 (i.e., both conditions (A1) and (A2) are satisfied, but condition (D3) is not satisfied), the CPU determines "No" in step 820 and proceeds directly to step 895. Note that even if there is no preceding vehicle, the CPU determines "No" in step 820 and proceeds directly to step 895.

As described above, the first modification device determines whether or not to execute the oncoming vehicle notification process based on the preceding vehicle. Therefore, even if the route crossing notification condition is not satisfied, the first modification device can execute the oncoming vehicle notification process at the timing when the third advance notification condition is satisfied. Therefore, according to the first modification device, it is possible to start the oncoming vehicle notification process early and the oncoming vehicle notification process is not operated unnecessarily. The CPU 31 of the ECU 22 may be configured to determine whether or not the "preceding vehicle has started to turn right (turn in a specific direction)" based on the forward image (history), and to determine that the condition (D3) is satisfied when it is determined that the preceding vehicle has started to turn right.

(Second Modification of the Notification Device)
Next, a second modified example (second modified device) of the present notification device will be described. The above-mentioned first modified device executes the oncoming vehicle notification process when at least one of the route crossing notification condition and the third advance notification condition is satisfied. In contrast, the second modified device executes the oncoming vehicle notification process when at least one of the route crossing notification condition and the "fourth advance notification condition" is satisfied. The differences will be described below.

<<Fourth advance notification condition>>
The fourth advance warning condition is satisfied when the conditions (A1), (A2), and the following condition (E3) are all satisfied: The preceding vehicle is a camera-detected target that satisfies all of the above-mentioned conditions (a), (b), (f), and (g).
Condition (A1): The right indicator 43R is activated (flashing).
Condition (A2): An oncoming vehicle is present.
Condition (E3): The vehicle that was determined to be the preceding vehicle starts turning to the right (i.e., making a right turn). Condition (E3) is satisfied when it is predicted (estimated) that the host vehicle is highly likely to start turning in a specific direction.

Next, the fourth advance notification condition will be described with reference to FIG. 9. In FIG. 9, the current position of vehicle 10 is indicated by vehicle position 10r. In this example, the driver is attempting to turn vehicle 10 right at an intersection. Specifically, the driver is attempting to move vehicle 10 from vehicle position 10r to vehicle position 10s, and then to vehicle position 10t. The dashed line Le5 indicates the driving route of vehicle 10 that is intended by the driver.

The predicted vehicle route when the vehicle 10 is at vehicle position 10r is indicated by dashed line Lh6. The predicted vehicle route when the vehicle 10 is at vehicle position 10s is indicated by the section of dashed line Lh6 in FIG. 9 that is above vehicle position 10s.

The other vehicle 66 shown in FIG. 9 is a other vehicle detected based on the forward image (i.e., a camera-detected target whose target type is "vehicle"). The position of the other vehicle 66 when the vehicle 10 is at vehicle position 10r is indicated by other vehicle position 66r. The position of the other vehicle 66 when the vehicle 10 is at vehicle position 10s is indicated by other vehicle position 66s.

The driver starts the operation (flashing) of the right indicator 43R when the vehicle 10 reaches the vehicle position 10r. Therefore, when the vehicle 10 reaches the vehicle position 10r, the condition (A1) is satisfied.

Although a detailed description is omitted, at least during the "period when vehicle 10 is traveling in the section from vehicle position 10r to vehicle position 10s," other vehicle 66 meets the requirements for an oncoming vehicle, and thus condition (A2) is met. On the other hand, conditions (A3) and (A4) are met after vehicle 10 passes vehicle position 10s. In other words, neither condition (A3) nor condition (A4) is met at the time when vehicle 10 reaches vehicle position 10s. In this example, conditions (A3) and (A4) are met at the time when vehicle 10 reaches vehicle position 10s, and as a result, the route crossing notification condition is met.

Next, condition (E3) will be described using another vehicle 67 shown in FIG. 9 as an example. The driver of the other vehicle (i.e., the preceding vehicle) 67 may turn right at the intersection without noticing the presence of the other vehicle 66 (i.e., the oncoming vehicle). Alternatively, the driver of the other vehicle 67 may attempt to make a right turn at the intersection before the other vehicle 66 reaches the intersection. In such a case, the driver of the vehicle 10 may mistakenly believe that there is no oncoming vehicle (i.e., the other vehicle 66). Therefore, when conditions (A1) and (A2) exist, if condition (E3) is met (i.e., the preceding vehicle starts to turn right), the oncoming vehicle notification process is executed.

The other vehicle 67 is a camera-detected object detected based on the forward image. The position of the other vehicle 67 when the vehicle 10 is at vehicle position 10r is indicated by other vehicle position 67r. The position of the other vehicle 65 when the vehicle 10 is at vehicle position 10s is indicated by other vehicle position 67s.

Although detailed description is omitted, during the period when vehicle 10 travels in the section from vehicle position 10r to vehicle position 10s, other vehicle 67 satisfies conditions (a), (b), and (f).

The left end position of the other vehicle 67 at the other vehicle position 67r is indicated by point Pg, and the right end position is indicated by point Ph. The left end position of the other vehicle 67 at the other vehicle position 67s is indicated by point Pi, and the right end position is indicated by point Pj.

As can be seen from FIG. 9, point Pg, which is the left end position of other vehicle position 67r, is to the left of dashed line Lh6 (i.e., the predicted path of vehicle 10 when vehicle position 10r is present), and point Ph, which is the right end position of other vehicle position 67r, is to the right of dashed line Lh6. Therefore, when vehicle 10 is at vehicle position 10r, condition (g) is satisfied, and therefore, at this point in time, other vehicle 67 is determined to be a leading vehicle.

On the other hand, point Pi, which is the left end position of other vehicle position 67s, and point Pj, which is the right end position of other vehicle position 67s, are both to the right of dashed line Lh6 (i.e., the predicted vehicle path of vehicle 10 at vehicle position 10s). More specifically, other vehicle position 67s indicates the position of other vehicle 67 immediately after the left end position transitions from the left to the right of dashed line Lh6. That is, at the time when vehicle 10 reaches vehicle position 10s, the leading vehicle (other vehicle 67) has moved to the right of vehicle 10 relative to the predicted vehicle path (dashed line Lh6). In other words, the other vehicle that was determined to be the leading vehicle at this time has started to turn to the right. Therefore, condition (E3) is satisfied at this time.

Therefore, when the vehicle 10 reaches the vehicle position 10s, in addition to the conditions (A1) and (A2), the condition (E3) is newly satisfied, and thus the fourth advance notification condition is satisfied (before the route crossing notification condition is satisfied).

(Specific Operation of the Second Deformation Device)
The CPU 31 (hereinafter also referred to simply as "CPU") of the vehicle control ECU 23 (hereinafter also referred to simply as "ECU 23") associated with the second transformation device executes an "oncoming vehicle notification determination processing routine" shown in the flowchart of Figure 10 every time a predetermined time has elapsed, instead of the "oncoming vehicle notification determination processing routine" shown in Figure 6.

Therefore, at an appropriate timing, the CPU starts processing from step 1000 in FIG. 10 and executes processing of steps 605 and after. If the CPU determines "No" in step 620 (i.e., condition (A1) and condition (A2) are satisfied, but condition (A3) is not satisfied), it proceeds to step 1020.

In step 1020, the CPU determines whether or not a preceding vehicle was present immediately before this time point, and if a preceding vehicle was present, determines whether or not this routine is being executed for the first time after the vehicle determined to be the preceding vehicle started to turn to the right. In other words, the CPU determines whether or not this routine is being executed for the first time after condition (E3) is satisfied.

If condition E3 is satisfied, the CPU judges "Yes" in step 1020 and proceeds to step 630 to start the notification process. In other words, in this case, the third advance notification condition is satisfied. Next, the CPU proceeds to step 1095 to end the processing of this routine.

On the other hand, if the preceding vehicle has not started turning to the right (if condition E3 is not met), the CPU determines "No" in step 1020 and proceeds directly to step 1095.

As described above, the second modification device determines whether or not to execute the oncoming vehicle notification process based on the preceding vehicle. Therefore, even if the route crossing notification condition is not satisfied, the second modification device can execute the oncoming vehicle notification process at the timing when the fourth advance notification condition is satisfied. Therefore, according to the second modification device, it is possible to start the oncoming vehicle notification process early and the oncoming vehicle notification process is not operated unnecessarily.

(Third Modification of the Notification Device)
A third modified example of the present notification device (third modified device) executes oncoming vehicle notification processing when at least one of the route crossing notification condition, the "fifth advance notification condition", and the "sixth advance notification condition" is satisfied.

<<Fifth advance notification condition>>
The fifth advance warning condition is satisfied when the above-mentioned conditions (A1) and (A2) and the following condition (F3) are all satisfied. That is, the fifth advance warning condition is satisfied when the following conditions are all satisfied:
Condition (A1): The right indicator 43R is activated (flashing).
Condition (A2): An oncoming vehicle is present.
Condition (F3): An oncoming vehicle is traveling in the adjacent lane to the right. That is, the oncoming lane in which the oncoming vehicle is traveling is adjacent to the lane in which the vehicle 10 is traveling. Condition (F3) is satisfied when the driver of the host vehicle should be aware of the presence of an oncoming vehicle before the host vehicle starts to turn in a specific direction.

<<Sixth advance notification condition>>
The sixth advance warning condition is satisfied when the above-mentioned conditions (A1) and (A2) and the following condition (F4) are all satisfied. That is, the sixth advance warning condition is satisfied when the following conditions are all satisfied:
Condition (A1): The right indicator 43R is activated (flashing).
Condition (A2): An oncoming vehicle is present.
Condition (F4): The magnitude of the lateral position Dx of the oncoming vehicle (lateral distance |Dx|) is smaller than a predetermined first threshold distance Dth1 (i.e., lateral distance |Dx|<Dth1). The first threshold distance Dth1 is set to a value that is slightly larger than the width of the travel lane in many cases. Condition (F4) is a condition that is satisfied when the driver of the host vehicle should recognize the presence of an oncoming vehicle before the host vehicle starts to turn in a specific direction.

The fifth and sixth advance warning conditions will be described in detail with reference to FIG. 11. In FIG. 11, the current position of the vehicle 10 is indicated by vehicle position 10u. In this example, the driver is changing lanes to the adjacent lane to the right (right side), and then intends to turn the vehicle 10 right at the intersection. Specifically, the driver is intending to make the vehicle 10 travel from vehicle position 10u to vehicle position 10y via vehicle positions 10v and 10x. The dashed line Le6 indicates the driving route of the vehicle 10 that the driver intends.

The other vehicle 68 shown in FIG. 11 is a other vehicle detected based on a forward image (i.e., a camera-detected target whose target type is "vehicle"). The position of the other vehicle 68 when the vehicle 10 is at vehicle position 10u is indicated by other vehicle position 68u. The position of the other vehicle 68 when the vehicle 10 is at vehicle position 10v is indicated by other vehicle position 68v. The position of the other vehicle 68 when the vehicle 10 is at vehicle position 10w is indicated by other vehicle position 68w. The position of the other vehicle 68 when the vehicle 10 is at vehicle position 10x is indicated by other vehicle position 68x.

The predicted oncoming vehicle path of the other vehicle 68 at the other vehicle position 68u is indicated by the dashed line Ls3. In this example, the other vehicle 68 is traveling straight.

The driver starts the operation (flashing) of the right indicator 43R when the vehicle 10 reaches the vehicle position 10u. Therefore, when the vehicle 10 reaches the vehicle position 10u, the condition (A1) is satisfied.

Although a detailed description is omitted, at least during the "period in which vehicle 10 is traveling in the section from vehicle position 10u to vehicle position 10x," other vehicle 68 satisfies the requirements for an oncoming vehicle (conditions (a) to (e) described above). Therefore, condition (A2) is met. In addition, after vehicle 10 reaches vehicle position 10x, both conditions (A3) and (A4) are met, and as a result, the route crossing notification condition is met.

Next, the satisfaction of the fifth advance warning condition will be described. When the driving assistance ECU 24 associated with the third modification device determines that the condition (A2) is satisfied (i.e., an oncoming vehicle is present) and that an intermediate lane, which will be described later, does not exist, the driving assistance ECU 24 determines that the condition (F3) is satisfied. That is, when the ECU 24 determines that an oncoming vehicle is present and that an intermediate lane does not exist, the ECU 24 determines that the oncoming vehicle is traveling in the adjacent lane to the right.
The intermediate lane is another lane located between the oncoming lane in which an oncoming vehicle is traveling and the driving lane of the vehicle 10. The ECU 24 determines that an intermediate lane exists when the following condition (x1) and condition (x2) are both satisfied.
Condition (x1): Both the right lane marking and the adjacent right lane marking are detected.
Condition (x2): The predicted path of the oncoming vehicle (in this example, the dashed line Ls3) is located to the right of the adjacent right lane marking with respect to the vehicle 10.

Specifically, when the vehicle 10 is at vehicle position 10u, the dividing line Lm1 is detected as the right dividing line and the dividing line Lm2 is detected as the adjacent right dividing line, and an intermediate lane defined by the dividing line Lm1 and the dividing line Lm2 exists. In this case, the predicted path of the oncoming vehicle (dashed line Ls3) is to the right of the adjacent right dividing line (dividing line Lm2) relative to the vehicle 10. Therefore, since the conditions (x1) and (x2) are satisfied, the ECU 24 determines that an intermediate lane exists, and therefore determines that the condition (F3) is not satisfied at this point in time.

After that, when the vehicle 10 reaches the vehicle position 10v, the lane marking Lm2 is detected as the right lane marking and the lane marking Lm3 is detected as the adjacent right lane marking. The dashed line Ls3 (i.e., the predicted route of the oncoming vehicle) is to the left of the lane marking Lm3 with respect to the vehicle 10. Therefore, in this case, since there is no intermediate lane (i.e., the other vehicle 68 is traveling in the adjacent lane to the right), the condition (F3) is met, and thus the fifth advance warning condition is met.

Next, we will explain whether the sixth advance warning condition is met. When the vehicle 10 is at the vehicle position 10u, the magnitude |Dx| of the lateral position Dx of the other vehicle 68 at the other vehicle position 68u is greater than the first threshold distance Dth1. Therefore, at this point in time, the condition (F4) is not met.

After that, when the vehicle 10 is changing lanes from the driving lane to the adjacent lane to the right of the vehicle 10 (i.e., the lane defined by the dividing line Lm1 and the dividing line Lm2), the magnitude |Dx| of the lateral position Dx of the other vehicle 68 decreases. Then, when the vehicle 10 reaches the vehicle position 10w, the magnitude |Dx| of the lateral position Dx of the other vehicle 68 becomes smaller than the first threshold distance Dth1. Therefore, the condition (F4) is met when the vehicle 10 reaches the vehicle position 10w, and the sixth advance warning condition is met.

(Specific Operation of the Third Transformation Device)
The CPU 31 (hereinafter, also referred to simply as the "CPU") of the driving assistance ECU 24 relating to the third modification device executes an "oncoming vehicle notification determination processing routine" shown by the flowchart in FIG. 12 instead of the "oncoming vehicle notification determination processing routine" shown in FIG. 6 every time a predetermined time has elapsed.

Therefore, at an appropriate timing, the CPU starts processing from step 1200 in FIG. 12 and executes processing of steps 605 and after. If the CPU judges "No" in step 620 (i.e., condition (A1) and condition (A2) are satisfied, but condition (A3) is not satisfied), it proceeds to step 1245.

In step 1245, the CPU determines whether an oncoming vehicle is traveling in the adjacent lane to the right. That is, the CPU determines whether condition (F3) is satisfied.

If the oncoming vehicle is traveling in the adjacent lane to the right (i.e., if condition (F3) is met), the CPU judges "Yes" in step 1245 and proceeds to step 630 to start the notification process.

On the other hand, if the oncoming vehicle is not traveling in the adjacent lane to the right (i.e., if condition (F3) is not met), the CPU determines "No" in step 1245 and proceeds to step 1250. In step 1250, the CPU determines whether the lateral distance |Dx|, which is the magnitude of the lateral position Dx of the oncoming vehicle, is smaller than the first threshold distance Dth1. In other words, the CPU determines whether condition (F4) is met.

If the magnitude |Dx| of the lateral position Dx of the oncoming vehicle is smaller than the first threshold distance Dth1 (i.e., if condition (F4) is satisfied), the CPU judges "Yes" in step 1250 and proceeds to step 630. On the other hand, if the magnitude |Dx| of the lateral position Dx of the oncoming vehicle is equal to or larger than the first threshold distance Dth1 (i.e., if condition (F4) is not satisfied), the CPU judges "No" in step 1250 and proceeds directly to step 1295, terminating the processing of this routine.

As described above, the third modification device can start the oncoming vehicle notification process when an oncoming vehicle is traveling in the adjacent lane to the right. In other words, the oncoming vehicle notification process can be executed at an appropriate timing.

(Fourth Modification of the Notification Device)
Next, a fourth modified example of the present notification device (fourth modified device) executes an oncoming vehicle notification process when at least one of the route crossing notification condition and the "seventh advance notification condition" is satisfied.

<<Seventh advance notification condition>>
The seventh advance warning condition is satisfied when the above-mentioned "condition (A1), condition (A2) and condition (B3a)" and the following condition (G4) are all satisfied. That is, the seventh advance warning condition is satisfied when the above-mentioned first advance warning condition is satisfied and further condition (G4) is satisfied.
Condition (A1): The right indicator 43R is activated (flashing).
Condition (A2): An oncoming vehicle is present.
Condition (B3a): The right-turn passing area of the vehicle 10 does not include a right lane marking.
Condition (G4): There is no "crossing vehicle" as described later.

The seventh advance notification condition will be described with reference to FIG. 13. In FIG. 13, the current position of vehicle 10 is indicated by vehicle position 10z. In this example, the driver is attempting to turn vehicle 10 right at an intersection. Specifically, the driver is attempting to make vehicle 10 travel from vehicle position 10z to vehicle position 10C via vehicle position 10A and vehicle position 10B. The dashed line Le7 indicates the driving route of vehicle 10 that is intended by the driver.

The other vehicle 69 shown in FIG. 13 is a other vehicle detected based on a forward image (i.e., a camera-detected target whose target type is "vehicle"). The position of the other vehicle 69 when the vehicle 10 is at vehicle position 10z is indicated by other vehicle position 69z. The position of the other vehicle 69 when the vehicle 10 is at vehicle position 10A is indicated by other vehicle position 69A. The position of the other vehicle 69 when the vehicle 10 is at vehicle position 10B is indicated by other vehicle position 69B.

The predicted oncoming vehicle path of the other vehicle 69 at the other vehicle position 69z is indicated by the dashed line Ls4. In this example, the other vehicle 69 is traveling straight.

The driver starts the operation (flashing) of the right indicator 43R when the vehicle 10 reaches the vehicle position 10z. Therefore, when the vehicle 10 reaches the vehicle position 10z, the condition (A1) is satisfied.

Although a detailed description is omitted, at least "during the period when vehicle 10 is traveling in the section from vehicle position 10z to vehicle position 10B," other vehicle 69 satisfies the requirements for an oncoming vehicle (i.e., conditions (a) to (e)). Therefore, condition (A2) is met. On the other hand, conditions (A3) and (A4) are met after vehicle 10 passes vehicle position 10A. In other words, neither condition (A3) nor condition (A4) is met at the time when vehicle 10 reaches vehicle position 10A. In this example, conditions (A3) and (A4) are met at the time when vehicle 10 is moving from vehicle position 10A to vehicle position 10B, and as a result, the route crossing notification condition is met.

On the other hand, when the vehicle 10 reaches the vehicle position 10A, the right lane marking is no longer included in the area Rpn, which is the right turn passing area of the vehicle 10. In other words, the condition (B3a) is met when the vehicle 10 reaches the vehicle position 10A.

The other vehicle 71 shown in FIG. 13 is a other vehicle detected based on a forward image (i.e., a camera-detected target whose target type is "vehicle"). The position of the other vehicle 71 when the vehicle 10 is at vehicle position 10z is indicated by other vehicle position 71z. The position of the other vehicle 71 when the vehicle 10 is at vehicle position 10A is indicated by other vehicle position 71A. The position of the other vehicle 71 when the vehicle 10 is at vehicle position 10B is indicated by other vehicle position 71B.

The vehicle control ECU 25 (hereinafter also simply referred to as "ECU 25") associated with the fourth modification device determines that the other vehicle 71 is a crossing vehicle at least "during the period when the vehicle 10 is traveling in the section from vehicle position 10z to vehicle position 10B."

More specifically, a crossing vehicle is a camera-detected object that satisfies all of the above-mentioned condition (a) and the following conditions (h) and (i). That is, if all of the "conditions (a), (h), and (i)" listed below are satisfied, the ECU 25 determines that a crossing vehicle is present. As a result, the ECU 25 determines that the condition (G4) is not satisfied. For convenience, the condition that a crossing vehicle is present is also referred to as a "prohibited condition."
Condition (a): A camera-detected target is present, and the type of the target is a "vehicle."
Condition (h): The camera-detected object is a different object (other vehicle) from the oncoming vehicle, and the "estimated crossing vehicle path" of the camera-detected object and the estimated oncoming vehicle path of the oncoming vehicle intersect with each other.
Condition (i): The crossing time Tr is equal to or less than a predetermined second threshold time Tth2 (i.e., Tr≦Tth2).

Since the other vehicle 71 is a camera-detected object whose object type is "vehicle", condition (a) is satisfied. Condition (h) will now be described. The predicted crossing vehicle path is the predicted travel path of the camera-detected object. The predicted crossing vehicle path is obtained based on the position (i.e., lateral position Dx and longitudinal position Dy) and speed (i.e., lateral relative velocity Vx and longitudinal relative velocity Vy) of the camera-detected object, on the assumption that its speed and direction of movement will remain unchanged.

In FIG. 13, the predicted crossing vehicle path of other vehicle 71 at other vehicle position 71z is indicated by dashed line Ls5. In this example, other vehicle 71 is traveling straight. Therefore, the predicted oncoming vehicle path of other vehicle 71 at other vehicle position 71A is indicated by the section located to the right of other vehicle position 71A on the paper by dashed line Ls5 in FIG. 13. Similarly, the predicted oncoming vehicle path of other vehicle 71 at other vehicle position 71B is indicated by the section located below and to the right of other vehicle position 71B on the paper by dashed line Ls5 in FIG. 13.

As can be seen from FIG. 13, dashed line Ls4 and dashed line Ls5 intersect with each other at point Ps5. In other words, the predicted crossing vehicle path of other vehicle 71 and the predicted oncoming vehicle path of other vehicle 69 intersect with each other at least during the "period when vehicle 10 is traveling in the section from vehicle position 10z to vehicle position 10B," so condition (h) is satisfied.

Next, condition (i) will be described. The intersection time Tr is the time it takes for a camera-detected object that has the predicted crossing vehicle path as its predicted path to reach the predicted path of an oncoming vehicle. The intersection time Tr of the other vehicle 71 at the current time (i.e., the time when the vehicle 10 is at vehicle position 10z) is the time it takes for the other vehicle 71 to travel from the other vehicle position 71z to point Ps5. In this example, the intersection time Tr becomes equal to the second threshold time Tth2 when the vehicle 10 reaches vehicle position 10z. Therefore, condition (i) is satisfied at least during the "period when the vehicle 10 is traveling in the section from vehicle position 10z to vehicle position 10B".

In other words, condition (G4) is not met because the other vehicle 71 satisfies the requirements for a crossing vehicle (i.e., conditions (a), (h), and (i)) at least during the "period in which the vehicle 10 is traveling in the section from vehicle position 10z to vehicle position 10B." Therefore, the seventh advance notification condition is not met. Therefore, the ECU 25 starts the notification process when the vehicle 10 reaches vehicle position 10B (i.e., when the route crossing notification condition is met).

(Specific Operation of the Fourth Transformation Device)
The CPU 31 (hereinafter, also referred to simply as "CPU") of the ECU 25 relating to the fourth modification device executes an "oncoming vehicle notification determination processing routine" shown by the flowchart in Figure 14 instead of the "oncoming vehicle notification determination processing routine" shown in Figure 6 every time a predetermined time has elapsed.

Therefore, at an appropriate timing, the CPU starts processing from step 1400 in FIG. 14 and executes processing of steps 605 and after. If the CPU judges "No" in step 620 (i.e., condition (A1) and condition (A2) are satisfied, but condition (A3) is not satisfied), it proceeds to step 645.

If the CPU judges "Yes" in step 645 (i.e., condition (B3a) is satisfied), it proceeds to step 1450 and judges whether or not there is no crossing vehicle. In other words, the CPU judges whether or not condition (G4) is satisfied.

If there is no crossing vehicle (i.e., condition (G4) is met), the CPU judges "Yes" in step 1450 and proceeds to step 630. In other words, in this case, the seventh advance notification condition is met, so the CPU starts the notification process.

On the other hand, if a crossing vehicle is present, the CPU determines "No" in step 1450 and proceeds to step 1495, terminating processing of this routine.

If the judgment condition of step 645 is not met (i.e., if condition (B3a) is not met), the CPU judges "No" at step 645 and proceeds directly to step 1495.

As described above, the fourth modified device determines whether the prohibition condition is met based on whether a crossing vehicle is present. Therefore, the fourth modified device does not unnecessarily activate the oncoming vehicle notification process.

(Fifth Modification of the Present Notification Device)
A fifth modified example of the present notification device (fifth modified device) executes an oncoming vehicle notification process when at least one of the route crossing notification condition and the first advance notification condition is satisfied.

However, when the first advance warning condition is met, the vehicle control ECU 26 (hereinafter also referred to simply as "ECU 26") associated with the fifth modified device executes both the "first warning process" and the "second warning process" as oncoming vehicle warning processes when there is no "stop history" for the oncoming vehicle (when it is not retained). In contrast, when the first advance warning condition is met, and there is a "stop history" for the oncoming vehicle (when it is retained), only the second warning process is executed as oncoming vehicle warning processes.

The first notification process is a notification process that is executed using the display 46 without using the speaker 47. The second notification process is a notification process that is executed using the speaker 47 without using the display 46. The process in which both the first notification process and the second notification process are executed is the same as the oncoming vehicle notification process executed by the ECU 21 described above. In other words, it can be said that the ECU 21 described above is configured to start both the first notification process and the second notification process when at least one of the route crossing notification condition, the first advance notification condition, and the second advance notification condition is satisfied.

When the first advance warning condition is met, if there is a "stop history" for the oncoming vehicle, the ECU 26 issues a warning using the speaker 47 without using the display 46. In contrast, when the first advance warning condition is met, if there is no "stop history" for the oncoming vehicle, the ECU issues a warning using both the display 46 and the speaker 47.

Next, the above-mentioned stopping history will be explained. When the longitudinal position Dy of the oncoming vehicle is smaller than the predetermined second threshold distance Dth2 and the target traveling speed Vc of the oncoming vehicle is equal to or less than the predetermined third threshold speed Vth3, the ECU 26 determines that the oncoming vehicle has stopped. In the fifth modified example, the third threshold speed Vth3 is "0". When the ECU 26 determines that the oncoming vehicle has stopped, it retains the stopping history related to the oncoming vehicle from the time when the determination was made.

An example of an oncoming vehicle whose stopping history is stored will be described with reference to FIG. 15. In FIG. 15, the current position of vehicle 10 is indicated by vehicle position 10F. Vehicle 10 has reached vehicle position 10F via vehicle positions 10D and 10E. Solid line Le8 indicates the route that vehicle 10 has already traveled.

The driver starts the operation (flashing) of the right indicator 43R when the vehicle 10 reaches the vehicle position 10E. Therefore, when the vehicle 10 reaches the vehicle position 10E, the condition (A1) is satisfied.

In this example, the driver is attempting to turn vehicle 10 right at an intersection without traffic lights. Specifically, the driver is attempting to drive vehicle 10 from vehicle position 10F, through vehicle position 10G, to vehicle position 10H. The dashed line Le9 indicates the driver's intended travel route for vehicle 10.

The pedestrian 81 shown in FIG. 15 has just crossed the road by walking on the crosswalk. The current position of the pedestrian 81 is indicated by pedestrian position 81F. The position of the pedestrian 81 at the time when the vehicle 10 is at vehicle position 10D is indicated by pedestrian position 81D. The position of the pedestrian 81 at the time when the vehicle 10 is at vehicle position 10E is indicated by pedestrian position 81E. The solid line Lw1 indicates the path that the pedestrian 81 has already walked.

The other vehicle 72 is a vehicle detected based on the forward image (i.e., a camera-detected target whose target type is "vehicle") and is a vehicle recognized as an oncoming vehicle. The position of the other vehicle 72 during the period when the vehicle 10 travels from vehicle position 10D to vehicle position 10E is indicated by the other vehicle position 72D. More specifically, because a pedestrian 81 was walking on the crosswalk in front of the other vehicle 72, the other vehicle 72 was stopped at the other vehicle position 72D during the period when the vehicle 10 traveled from vehicle position 10D to vehicle position 10E.

After that (i.e., after the pedestrian 81 has completed crossing the road), the other vehicle 72 resumes traveling. The position of the other vehicle 72 at the time when the vehicle 10 is at vehicle position 10F is indicated by the other vehicle position 72F. The solid line Ls6 indicates the route that the other vehicle 72 has already traveled.

The position of the other vehicle 72 at the time when the vehicle 10 is at vehicle position 10G is indicated by the other vehicle position 72G. The predicted oncoming vehicle route of the other vehicle 72 at the other vehicle position 72F is indicated by the dashed line Ls7. In this example, the other vehicle 72 is traveling straight. Therefore, the predicted oncoming vehicle route of the other vehicle 72 at the other vehicle position 72G is indicated by the section that is below the other vehicle position 72G of the dashed line Ls7 in FIG. 15.

In this example, the other vehicle 72 has a stopping history after the other vehicle 72 reaches the other vehicle position 72D. More specifically, at the time when the vehicle 10 reaches the vehicle position 10D (the time when the other vehicle 72 reaches the other vehicle position 72D), the target traveling speed Vc of the other vehicle 72 becomes equal to the third threshold speed Vth3 (=0), and the longitudinal position Dy of the other vehicle 72 at that time is smaller than the second threshold distance Dth2. Therefore, the ECU 26 determines that the other vehicle 72, which is an oncoming vehicle, has stopped. Therefore, the other vehicle 72 started traveling at the time when the vehicle 10 reached the vehicle position 10E, but the stopping history of the other vehicle 72 is retained (exists).

Although a detailed description is omitted, at least during the "period when vehicle 10 is traveling in the section from vehicle position 10F to vehicle position 10G," other vehicle 72 satisfies the requirements for an oncoming vehicle (i.e., conditions (a) to (e)), so condition (A2) is met. However, at the time when vehicle 10 reaches vehicle position 10F, neither condition (A3) nor condition (A4) is met. Note that in this example, after vehicle 10 reaches vehicle position 10G, conditions (A3) and (A4) are met, and as a result, the route crossing notification condition is met.

In addition, when the vehicle 10 reaches the vehicle position 10F, the right lane marking is no longer included in the area Rpo, which is the right-turn passing area of the vehicle 10. In other words, the condition (B3a) is met when the vehicle 10 reaches the vehicle position 10F. Therefore, the first advance warning condition is met when the vehicle 10 reaches the vehicle position 10F.

In this case (i.e., when the first advance warning condition is satisfied), as described above, the vehicle control ECU 26 of the fifth modified device executes only the second warning process as the oncoming vehicle warning process when there is a "stop history" for the oncoming vehicle. Therefore, in the above example, since there is a stop history for the oncoming vehicle (i.e., the other vehicle 72), the ECU 26 starts the second warning process (warning process executed using the speaker 47) when the vehicle 10 reaches the vehicle position 10F and the first advance warning condition is satisfied. After that, when the vehicle 10 reaches the vehicle position 10G (i.e., when the route crossing warning condition is satisfied), the ECU 26 starts the first warning process. That is, the ECU 26 executes the first warning process (warning process executed using the display 46) in addition to the second warning process.

In contrast, if there is no history of the other vehicle 72 stopping, the ECU 26 starts both the first notification process and the second notification process when the vehicle 10 reaches the vehicle position 10F.

(Specific Operation of the Fifth Transformation Device)
The CPU 31 (hereinafter, also referred to simply as "CPU") of the driving assistance ECU 26 relating to the fifth modified device executes an "oncoming vehicle notification determination processing routine" shown by the flowchart in FIG. 16 every time a predetermined time has elapsed, instead of the "oncoming vehicle notification determination processing routine" shown in FIG. 6.

Therefore, at an appropriate timing, the CPU starts processing from step 1600 in FIG. 16 and proceeds to step 1605 to determine whether the second notification process is not being executed. In other words, when both the first notification process and the second notification process are being executed, or when only the second notification process is being executed, the CPU determines "No" in step 1605 and proceeds to step 635.

If the judgment condition of step 635 is not met (i.e., the notification end condition is not met), the CPU judges "No" at step 635 and proceeds to step 610.

In addition, if the second notification process is not being executed when the CPU proceeds to step 1605, the CPU determines "Yes" in step 1605 and proceeds to step 610.

If the CPU judges "Yes" in step 625 (i.e., the route crossing notification condition is met), it proceeds to step 1630 and executes the first notification process. More specifically, if the first notification process is not being executed (i.e., if the first notification process has not already started), the CPU starts the first notification process by displaying an oncoming vehicle warning symbol on the display 46. On the other hand, if the first notification process is being executed, the CPU continues executing the first notification process.

Then, the CPU proceeds to step 1632 and executes the second notification process. More specifically, if the second notification process is not being executed (i.e., if the second notification process has not already started), the CPU starts the second notification process by causing the speaker 47 to emit an oncoming vehicle warning sound. On the other hand, if the second notification process is being executed, the CPU continues executing the second notification process. After that, the CPU proceeds to step 1695 and ends the processing of this routine.

If the CPU judges "Yes" in step 645 (i.e., the route crossing notification condition is not satisfied, but the first advance notification condition is satisfied because condition (B3a) is satisfied), the CPU proceeds to step 1650. In step 1650, the CPU judges whether a stopping history for the oncoming vehicle is stored (exists).

If a stopping history for the oncoming vehicle is stored (exists), the CPU judges "Yes" in step 1650 and proceeds to step 1632, where it executes the second notification process as the oncoming vehicle notification process. On the other hand, if a stopping history is not stored (does not exist) for the oncoming vehicle, the CPU judges "No" in step 1650 and proceeds to steps 1630 and 1632. As a result, both the "first notification process and the second notification process" are executed as the oncoming vehicle notification process.

According to the fifth modified device, the fulfillment of the prohibition condition is determined based on whether or not there is a stopping history of the oncoming vehicle. Therefore, according to the fifth modified device, the oncoming vehicle notification process is not activated unnecessarily.

In addition, according to the fifth modified device, when the prohibition condition is satisfied, the second notification process is not executed, and only the first notification process is executed. This reduces the possibility that the driver will feel annoyed due to the execution of the notification process.

For convenience, the condition that is met when a stop history related to an oncoming vehicle is stored (exists) is also referred to as a "prohibition condition (stop history prohibition condition)." Furthermore, in the modified fifth modified device, when the stop history prohibition condition is met, not only the second notification process but also the first notification process may be prohibited. In other words, when the CPU determines "Yes" at step 1650 in FIG. 16, it may proceed directly to step 1695 without proceeding to step 1632.

(Sixth Modification of the Present Notification Device)
A sixth modified example of the present notification device (sixth modified device) executes oncoming vehicle notification processing when at least one of the route crossing notification condition, the "eighth advance notification condition" and the "ninth advance notification condition" is satisfied.

<<Eighth advance notification condition>>
The eighth advance warning condition is satisfied when the above-mentioned "condition (A1), condition (A2) and condition (B3a)" and the below-described "condition (H4a) and condition (H5a)" are all satisfied. That is, the eighth advance warning condition is satisfied when the following conditions are all satisfied.
Condition (A1): The right indicator 43R is activated (flashing).
Condition (A2): An oncoming vehicle is present.
Condition (B3a): The right-turn passing area of the vehicle 10 does not include a right lane marking.
Condition (H4a): The vehicle speed Vs of the vehicle 10 is equal to or lower than a predetermined fourth threshold speed Vth4 (i.e., Vs≦Vth4).
Condition (H5a): The magnitude of the lateral position Dx of the oncoming vehicle (lateral distance |Dx|) is smaller than a predetermined third threshold distance Dth3 (i.e., |Dx|<Dth3). The third threshold distance Dth3 is preset so as to be approximately equal to the upper limit value of the magnitude of the lateral position Dx (lateral distance |Dx|) that the oncoming vehicle can have when traveling in a lane adjacent to the traveling lane (adjacent lane to the right).

<<Ninth advance notification condition>>
The ninth advance warning condition is satisfied when the above-mentioned "condition (A1), condition (A2) and condition (B3a)" and the below-described "condition (H4b) and condition (H5b)" are all satisfied. That is, the ninth advance warning condition is satisfied when the following conditions are all satisfied.
Condition (A1): The right indicator 43R is activated (flashing).
Condition (A2): An oncoming vehicle is present.
Condition (B3a): The right-turn passing area of the vehicle 10 does not include a right lane marking.
Condition (H4b): The vehicle speed Vs of the vehicle 10 is greater than a fourth threshold speed Vth4 (i.e., Vs>Vth4).
Condition (H5b): The magnitude of the lateral position Dx of the oncoming vehicle (lateral distance |Dx|) is smaller than a predetermined fourth threshold distance Dth4 (i.e., |Dx|<Dth4). The fourth threshold distance Dth4 is a value larger than the third threshold distance Dth3 (i.e., Dth3<Dth4) and is preset so as to substantially coincide with the upper limit value of the magnitude of the lateral position Dx (lateral distance |Dx|) that the oncoming vehicle can take when it is traveling in "a lane adjacent to the right adjacent lane with respect to the vehicle 10."

In addition, "condition (H4a) and condition (H5a)" included in the eighth advance warning condition and "condition (H4b) and condition (H5b)" included in the ninth advance warning condition can be summarized as the following condition (H6).
Condition (H6): The magnitude of the lateral position Dx of the oncoming vehicle (lateral distance |Dx|) is smaller than a lateral threshold distance (Dxyth) that increases as the vehicle speed Vs of the vehicle 10 increases.

The eighth advance notification condition will be described with reference to FIG. 17. In FIG. 17, the current position of vehicle 10 is indicated by vehicle position 10J. In this example, the driver is attempting to turn vehicle 10 right at an intersection. Specifically, the driver is attempting to drive vehicle 10 from vehicle position 10J, via vehicle position 10K and vehicle position 10L, to vehicle position 10M. The dashed line Le10 indicates the driving route of vehicle 10 that is intended by the driver.

The other vehicle 73 shown in FIG. 17 is a other vehicle detected based on a forward image (i.e., a camera-detected target whose target type is "vehicle"). The position of the other vehicle 73 when the vehicle 10 is at vehicle position 10J is indicated by other vehicle position 73J. The position of the other vehicle 73 when the vehicle 10 is at vehicle position 10K is indicated by other vehicle position 73K. The position of the other vehicle 73 when the vehicle 10 is at vehicle position 10L is indicated by other vehicle position 73L.

The predicted oncoming vehicle path of the other vehicle 73 at the other vehicle position 73J is indicated by the dashed line Ls8. In this example, the other vehicle 73 is traveling straight.

The driver starts the operation (flashing) of the right indicator 43R when the vehicle 10 reaches the vehicle position 10J. Therefore, when the vehicle 10 reaches the vehicle position 10J, the condition (A1) is satisfied.

Although a detailed description is omitted, at least during the "period when vehicle 10 is traveling in the section from vehicle position 10J to vehicle position 10L," other vehicle 73 satisfies the requirements for an oncoming vehicle (i.e., conditions (a) to (e)). Therefore, condition (A2) is met during this period. On the other hand, when vehicle 10 reaches vehicle position 10K, neither condition (A3) nor condition (A4) is met. Note that, in this example, after vehicle 10 reaches vehicle position 10L, conditions (A3) and (A4) are met, and as a result, the route crossing notification condition is met.

Furthermore, when the vehicle 10 reaches the vehicle position 10K, the right lane marking is no longer included in the area Rpp, which is the right-turn passing area of the vehicle 10. In other words, the condition (B3a) is met when the vehicle 10 reaches the vehicle position 10K.

In this example, when the vehicle 10 reaches the vehicle position 10K, the vehicle speed Vs is equal to or less than the fourth threshold speed Vth4. Therefore, condition (H4a) is satisfied at this time. Furthermore, as can be seen from FIG. 17, the magnitude (|Dx|) of the lateral position Dx of the other vehicle 73 at this time is smaller than the third threshold distance Dth3, so condition (H5a) is satisfied. Therefore, the eighth advance warning condition is satisfied when the vehicle 10 reaches the vehicle position 10K.

Next, the ninth advance notification condition will be described with reference to FIG. 18. In FIG. 18, the current position of vehicle 10 is indicated by vehicle position 10N. In this example, the driver is attempting to turn vehicle 10 right at an intersection. Specifically, the driver is attempting to make vehicle 10 travel from vehicle position 10N to vehicle position 10R via vehicle position 10P and vehicle position 10Q. The dashed line Le11 indicates the driving route of vehicle 10 that the driver intends.

The other vehicle 74 shown in FIG. 18 is a other vehicle detected based on the forward image (i.e., a camera-detected target whose target type is "vehicle"). The position of the other vehicle 74 when the vehicle 10 is at vehicle position 10N is indicated by other vehicle position 74N. The position of the other vehicle 74 when the vehicle 10 is at vehicle position 10P is indicated by other vehicle position 74P. The position of the other vehicle 74 when the vehicle 10 is at vehicle position 10Q is indicated by other vehicle position 74Q.

The predicted oncoming vehicle path of the other vehicle 74 at the other vehicle position 74N is indicated by the dashed line Ls9. In this example, the other vehicle 74 is traveling straight.

The driver starts the operation (flashing) of the right indicator 43R when the vehicle 10 reaches the vehicle position 10N. Therefore, when the vehicle 10 reaches the vehicle position 10N, the condition (A1) is satisfied.

Although a detailed description is omitted, at least during the "period when vehicle 10 is traveling in the section from vehicle position 10N to vehicle position 10Q," other vehicle 74 satisfies the requirements (a) to (e) of an oncoming vehicle. Therefore, condition (A2) is met during this period. On the other hand, when vehicle 10 reaches vehicle position 10P, neither condition (A3) nor condition (A4) is met. Note that, in this example, after vehicle 10 reaches vehicle position 10Q, conditions (A3) and (A4) are met, and as a result, the route crossing notification condition is met.

Furthermore, when the vehicle 10 reaches the vehicle position 10P, the right lane marking is no longer included in the area Rpq, which is the right-turn passing area of the vehicle 10. In other words, the condition (B3a) is met when the vehicle 10 reaches the vehicle position 10P.

In this example, when the vehicle 10 reaches the vehicle position 10P, the vehicle speed Vs is greater than the fourth threshold speed Vth4. Therefore, condition (H4b) is satisfied at this time. Furthermore, as can be seen from FIG. 18, the magnitude (|Dx|) of the lateral position Dx of the other vehicle 74 at this time is smaller than the fourth threshold distance Dth4, so condition (H5b) is satisfied. Therefore, the ninth advance warning condition is satisfied when the vehicle 10 reaches the vehicle position 10P.

(Specific Operation of the Sixth Transformation Device)
The CPU 31 (hereinafter, also referred to simply as the "CPU") of the driving assistance ECU 27 relating to the sixth modified device executes an "oncoming vehicle notification determination processing routine" shown by the flowchart in FIG. 19 instead of the "oncoming vehicle notification determination processing routine" shown in FIG. 6 every time a predetermined time has elapsed.

Therefore, at an appropriate timing, the CPU starts processing from step 1900 in FIG. 19 and executes processing of steps 605 and after. If the CPU judges "Yes" at 645 (i.e., if condition (A1), condition (A2), and condition (B3a) are satisfied), the CPU proceeds to step 1945 and judges whether the vehicle speed Vs of the vehicle 10 is equal to or less than the fourth threshold speed Vth4. In other words, the CPU judges whether condition (H4a) is satisfied.

If the vehicle speed Vs is equal to or less than the fourth threshold speed Vth4, the CPU judges "Yes" in step 1945 and proceeds to step 1950 to determine whether the magnitude of the lateral position Dx of the oncoming vehicle (|Dx|) is smaller than the third threshold distance Dth3. In other words, the CPU determines whether the condition (H5a) is satisfied.

If the magnitude of the lateral position Dx of the oncoming vehicle (|Dx|) is smaller than the third threshold distance Dth3, the CPU judges "Yes" in step 1950 and proceeds to step 630. In other words, in this case, the eighth advance warning condition is met, so the CPU starts the warning process.

On the other hand, if the vehicle speed Vs is greater than the fourth threshold speed Vth4 (i.e., if condition (H4b) is satisfied), the CPU determines "No" in step 1945 and proceeds to step 1955 to determine whether the magnitude (|Dx|) of the lateral position Dx of the oncoming vehicle is smaller than the fourth threshold distance Dth4. In other words, the CPU determines whether condition (H5b) is satisfied.

If the lateral position Dx of the oncoming vehicle is smaller than the fourth threshold distance Dth4, the CPU judges "Yes" in step 1955 and proceeds to step 630. That is, in this case, the ninth advance warning condition is met, so the CPU starts the warning process. In contrast, if the lateral position Dx of the oncoming vehicle is equal to or greater than the fourth threshold distance Dth4, the CPU judges "No" in step 1955 and proceeds directly to step 1995.

If the determination condition of step 1950 is not met (i.e., if the magnitude of the lateral position Dx of the oncoming vehicle (|Dx|) is equal to or greater than the third threshold distance Dth3), the CPU determines "No" in step 1950 and proceeds directly to step 1995.

The sixth modification device can perform oncoming vehicle notification processing at appropriate timing in both cases where an oncoming vehicle is traveling in the adjacent lane to the right and where an oncoming vehicle is traveling in a lane further to the right of the adjacent lane to the right.

(Seventh Modification of the Present Notification Device)
A seventh modified example of the present notification device (seventh modified device) executes an oncoming vehicle notification process when at least one of the route crossing notification condition and the "tenth advance notification condition" is satisfied.

<<Tenth advance notification condition>>
The tenth advance notification condition is satisfied when the above-mentioned "condition (A1), condition (A2), and condition (B3a)" and the following condition (J4) are all satisfied. That is, the tenth advance notification condition is satisfied when the following conditions are all satisfied.
Condition (A1): The right indicator 43R is activated (flashing).
Condition (A2): An oncoming vehicle is present.
Condition (B3a): The right-turn passing area of the vehicle 10 does not include a right lane marking.
Condition (J4): The "prohibited condition (specific prohibited condition)" described later is not satisfied.

The prohibition condition (specific prohibition condition) of condition (J4) is a condition that is met when the following conditions (j), (k), and (m) are all met.
<<<Specific Prohibited Conditions>>>
Condition (j): The steering angle θs is smaller than a predetermined positive threshold angle θth (i.e., 0<θth and θs<θth). That is, the steering angle θs is a value in a direction that turns the vehicle 10 so as to cross the oncoming lane, and the magnitude |θs| of the steering angle θs is smaller than the threshold angle θth (|θs|<θth).
Condition (k): The brake pedal operation amount Bp is greater than a predetermined threshold operation amount Bth (i.e., Bp>Bth), i.e., the brake is being applied.
Condition (m): The vehicle speed Vs of the vehicle 10 is equal to or lower than a predetermined fifth threshold speed Vth5 (i.e., Vs≦Vth5).

In this modified example, the threshold operation amount Bth is "0." For convenience, the fifth threshold speed Vth5 is also referred to as the "specific speed."

(Specific Operation of the Seventh Transformation Device)
The CPU 31 (hereinafter, also referred to simply as the "CPU") of the driving assistance ECU 28 relating to the seventh modified device executes an "oncoming vehicle notification determination processing routine" shown by the flowchart in FIG. 20 instead of the "oncoming vehicle notification determination processing routine" shown in FIG. 6 every time a predetermined time has elapsed.

Therefore, at an appropriate timing, the CPU starts processing from step 2000 in FIG. 20 and executes processing of steps 605 and after. If the CPU judges "Yes" at 645 (i.e., if condition (A1), condition (A2), and condition (B3a) are satisfied), it proceeds to step 2050 and judges whether the steering angle θs is smaller than the threshold angle θth. In other words, the CPU judges whether condition (j) is satisfied.

If the steering angle θs is equal to or greater than the threshold angle θth (i.e., condition (j) is not satisfied, and therefore the prohibition condition (specific prohibition condition) is not satisfied), the CPU determines "No" in step 2050 and proceeds to step 630. In other words, in this case, the 10th advance notification condition is satisfied, so the CPU starts notification processing. After that, the CPU proceeds to step 2095 and ends processing of this routine.

On the other hand, if the steering angle θs is smaller than the threshold angle θth, the CPU judges "Yes" in step 2050 and proceeds to step 2055 to judge whether the brake pedal operation amount Bp is greater than the threshold operation amount Bth. That is, the CPU judges whether condition (k) is satisfied. If the brake pedal operation amount Bp is equal to or less than the threshold operation amount Bth (that is, if condition (k) is not satisfied and thus the prohibition condition (specific prohibition condition) is not satisfied), the CPU judges "No" in step 2055 and proceeds to step 630 to start the notification process.

If the brake pedal operation amount Bp is greater than the threshold operation amount Bth, the CPU judges "Yes" in step 2055 and proceeds to step 2060 to judge whether the vehicle speed Vs is less than the fifth threshold speed Vth5. That is, the CPU judges whether the condition (m) is satisfied. If the vehicle speed Vs is equal to or greater than the fifth threshold speed Vth5 (that is, if the condition (m) is not satisfied and thus the prohibition condition (specific prohibition condition) is not satisfied), the CPU judges "No" in step 2060 and proceeds to step 630 to start the notification process.

On the other hand, if the vehicle speed Vs is less than the fifth threshold speed Vth5 (i.e., if the prohibition condition is met), the CPU determines "Yes" in step 2060 and proceeds directly to step 2095.

According to the seventh modification device, the fulfillment of the prohibition conditions is determined based on the steering angle θs, the brake pedal operation amount Bp, and the vehicle speed Vs. Therefore, according to the seventh modification device, the oncoming vehicle notification process is not unnecessarily activated.

(Eighth Modification of the Present Notification Device)
Next, an eighth modified example of the present notification device (eighth modified device) will be described. The above-mentioned present notification device and modified example terminated the notification process when at least one of the conditions (C1) to (C3) was satisfied. In contrast, the eighth modified device terminates the notification process when either the "first notification end condition" described below is satisfied, or the state in which the "second notification end condition" described below is satisfied continues for a predetermined third threshold time Tth3 or more, whichever comes first. The specific description will be given below.

Whether or not the first notification end condition is met is determined based on the state of the driver's driving operation. More specifically, the first notification end condition is met when it is determined (estimated) that there is a high probability that the driver of the vehicle 10 is aware of the presence of an oncoming vehicle.

<<Conditions for ending the first notification>>
In this modified example, the first notification end condition is met when an end condition (END11) and an end condition (END12) described below are both met.
End condition (END11): The steering speed Ws, which is the amount of change in the steering angle θs per unit time, is a negative value. In other words, the driver is turning the steering wheel 51 to the left.
End condition (END12): The absolute value |Ws| of the magnitude of the steering speed Ws is greater than a predetermined threshold angular velocity Wth (i.e., |Ws|>Wth>0). The threshold angular velocity Wth is preset so as to substantially coincide with the lower limit of the magnitude of the threshold angular velocity Wth when the driver, who notices the presence of an oncoming vehicle after starting to turn right of the vehicle 10, turns the steering wheel 51 to the left. In this modified example, the steering angle sensor 45 is also referred to as a "driving state sensor or driving operation state sensor" for convenience.

<<Conditions for ending the second notification>>
The second notification end condition is determined based on at least one of the vehicle speed Vs of the vehicle 10 and the surrounding information. More specifically, the second notification end condition is a condition that is met when it is determined that there is no longer a possibility of the vehicle 10 colliding with an oncoming vehicle. In this modification, the second notification end condition is a condition that is met when the condition (C2) is met (i.e., when an oncoming vehicle no longer exists).

(Specific operation of the eighth transformation device)
A CPU 31 (hereinafter also simply referred to as "CPU") of a driving assistance ECU 29 (hereinafter also simply referred to as "ECU 29") according to the eighth modified device executes an "oncoming vehicle alert determination processing routine" shown by a flowchart in Fig. 21 every time a predetermined time elapses, instead of the "oncoming vehicle alert determination processing routine" shown in Fig. 6. The routine shown in Fig. 21 is a routine obtained by deleting steps 635 and 640 from the routine shown in Fig. 6.

In addition, the CPU executes the "oncoming vehicle notification end processing routine" shown in the flowchart of FIG. 22 every time a predetermined time shorter than the third threshold time Tth3 elapses.

The value of the notification flag Xw used in the routine of FIG. 22 is set to "0" by an initialization routine (not shown) executed by the CPU when the ignition switch (not shown) of the vehicle 10 is turned on.

When the appropriate timing occurs, the CPU starts processing from step 2100 in FIG. 21 and proceeds to step 605. If the CPU determines "No" at step 605, it proceeds directly to step 2195 and ends processing of this routine. In contrast, if the CPU determines "No" at step 605, it performs processing of steps 610 and onward. As a result, when at least one of the route crossing notification condition, the first advance notification condition, and the second advance notification condition is met, notification processing is started (step 630).

When the appropriate timing arrives, the CPU starts processing from step 2200 in FIG. 22 and proceeds to step 2205 to determine whether or not the current state is a state in which notification processing is being executed. If the current state is not a state in which notification processing is being executed, the CPU determines "No" in step 2205 and proceeds to step 2295 to end processing of this routine.

In contrast, if the current state is one in which the notification process is being executed, the CPU judges "Yes" in step 2205 and proceeds to step 2210 to determine whether the above-mentioned first notification end condition (the condition that is met when the driver, who notices the presence of an oncoming vehicle after starting to turn right of the vehicle 10, operates the steering wheel 51 to the left) is met. That is, the CPU judges whether the end condition (END11) and the end condition (END12) are both met. If the first notification end condition is met, the CPU judges "Yes" in step 2210 and proceeds to step 640 to end the notification process.

The CPU then proceeds to step 2245, where it determines whether the value of the notification flag Xw is "1". As described below, the value of the notification flag Xw is set to "1" when the second notification end condition is met during the execution of the notification process (see step 2270). When the CPU proceeds to step 2245, if the value of the notification flag Xw is "1", the CPU determines "Yes" at step 2245 and proceeds to step 2250, where it sets the value of the notification flag Xw to "0". The CPU then proceeds to step 2295.

In contrast, when the CPU proceeds to step 2245, if the value of the notification flag Xw is not "1" (i.e., if the value of the notification flag Xw is "0"), the CPU determines "No" at step 2245 and proceeds directly to step 2295.

When the CPU proceeds to step 2210, if the first notification end condition is not met, the CPU determines "No" at step 2210 and proceeds to step 2255 to determine whether the second notification end condition is met. In other words, the CPU determines whether there is an oncoming vehicle.

If the second notification end condition is met, the CPU judges "Yes" at step 2255 and proceeds to step 2260 to determine whether the value of the notification flag Xw is "1". If the value of the notification flag Xw is "0", the CPU judges "No" at step 2260 and proceeds to step 2270 to set the value of the notification flag Xw to "1". In addition, the CPU stores in RAM 33 the time when the value of the notification flag Xw was set to "1" (flag change time). The CPU then proceeds to step 2295.

When this routine is next executed, if the first notification end condition is not satisfied and the second notification end condition remains satisfied, the CPU proceeds to step 2260 via step 2205, step 2210, and step 2255. The CPU determines "Yes" at step 2260 and proceeds to step 2265.

In step 2265, the CPU determines whether or not the third threshold time Tth3 or more has elapsed since the value of the notification flag Xw became "1." Specifically, the CPU determines whether or not the current time is a time after the time when the third threshold time Tth3 or more has elapsed since the flag change time stored in RAM 33.

If the third threshold time Tth3 or more has not elapsed after the value of the notification flag Xw becomes "1", the CPU determines "No" in step 2265 and proceeds directly to step 2295. In contrast, if the third threshold time Tth3 or more has elapsed after the value of the notification flag Xw becomes "1", the CPU determines "Yes" in step 2265 and proceeds to step 640. In this case, notification processing is started in step 640 and the value of the notification flag Xw is set to "0" in step 2250.

If the judgment condition of step 2255 is not met (i.e., if the second notification end condition is not met), the CPU judges "No" at step 2255 and proceeds to step 2245. If the CPU judges "No" at step 2255, it may proceed directly to step 2295.

According to the eighth modified device, when the first notification end condition is met (i.e., when it is presumed that the driver of the vehicle 10 has noticed the presence of an oncoming vehicle), the notification process is immediately terminated. Furthermore, according to the eighth modified device, when the state in which the second notification end condition is met (a state in which there is no oncoming vehicle) continues for more than the third threshold time Tth3, the notification process is terminated. Therefore, when a safer state is confirmed, the notification process can be terminated.

Although the embodiment and modified examples of the notification device according to the present invention have been described above, the present invention is not limited to the above embodiment and modified examples, and various modified examples can be adopted within the scope of the present invention. For example, the specific direction in the above embodiment and modified examples was to the right. However, in areas where laws stipulate that vehicles must drive on the right side of the road (right-hand traffic areas), the specific direction is to the left.

In addition, in this embodiment, the right-turn passing area is an area defined based on fixed values (specifically, distance Dx1, distance Dy1, distance Dy2, and vehicle width Wd). However, the right-turn passing area may be an area different from this. For example, the right-turn passing area may be defined such that the length in the X-axis direction of the right-turn passing area increases as the width of the travel lane (i.e., the distance between the right lane marking and the left lane marking) increases.

In addition, each of ECU21 to ECU29 according to this embodiment determines that an oncoming vehicle is present if all of the above-mentioned conditions (a) to (e) are satisfied. However, the conditions for determining whether a camera-detected object is an oncoming vehicle may be different.

For example, each of ECU21 to ECU29 may be configured to determine that condition (b) is satisfied when the vertical position Dy of the camera-detected target is a positive value and is smaller than a predetermined fifth threshold distance Dth5 (i.e., 0<Dy<Dth5).

Alternatively, each of the ECUs 21 to 29 may be configured to determine that an oncoming vehicle is present when all of the conditions (a) to (e) and the following condition (n) are satisfied.
Condition (n): The magnitude of the reference time Tt, which is a value obtained by dividing the longitudinal position Dy of the camera-detected target by the longitudinal relative speed Vy, is smaller than a predetermined standard time Ts (i.e., |Tt|<Ts). In this case, another vehicle that is relatively far away from the vehicle 10 or that takes a long time to approach the vehicle 10 is not determined to be an oncoming vehicle.

In addition, the ECU 22 and ECU 23 according to the present embodiment acquire the predicted path of the vehicle as a straight line or a curve, and determine whether or not condition (g) is satisfied based on the positional relationship between the predicted path of the vehicle and the "left end position of the other vehicle and the right end position of the other vehicle". However, condition (g) may be different. For example, the ECU 22 and ECU 23 may be configured to acquire a strip-shaped area having a predetermined width (e.g., half the vehicle width Wd (Wd/2), or half the vehicle width plus a margin α (α+Wd/2)) in the left-right direction of the predicted path of the vehicle as the predicted travel area. In other words, the predicted travel area is an area through which the vehicle 10 passes when traveling, and the width of the area is approximately the vehicle width Wd. Each of these ECUs may be configured to determine that condition (g) is satisfied when a part or all of the camera-detected target (specifically, another vehicle) is included in the predicted travel area.

In addition, if the right-turn passing area includes a right lane marking (specifically, a road marking drawn by a solid or dashed line in white or yellow), it was determined that condition (B3b) is met. However, condition (B3b) may also be determined to be met when the right-turn passing area includes a median strip.

In addition, the ECU 22 according to the present embodiment determines that the third advance warning condition is satisfied when all of the conditions (A1), (A2), and (D3) are satisfied. However, the ECU 22 may be configured to determine that the third advance warning condition is satisfied when all of the conditions (A1), (A2), and (D3) as well as the following condition (D4) are satisfied.
Condition (D4): The right turn signal of the preceding vehicle is in an activated (flashing) state, and the left turn signal of the preceding vehicle is in an inactivated state.
In this case, the ECU 22 determines whether or not the direction indicator of the preceding vehicle is in an activated state based on the history of forward images (a plurality of forward images acquired within a predetermined period of time).

In addition, the ECU 25 determines that a camera-detected object that satisfies all of the conditions (a), (h), and (i) is a crossing vehicle. However, the ECU 25 may be configured to determine that a camera-detected object that satisfies all of the conditions (a), (h), (i), and the condition (p) described below is a crossing vehicle. Furthermore, the ECU 25 may be configured to replace the condition (h) with the condition (p) and determine that a camera-detected object that satisfies all of the conditions (a), (i), and (p) is a crossing vehicle.
Condition (p): The camera-detected object is a different object (other vehicle) from an oncoming vehicle, and the "predicted crossing vehicle path" of the object and the predicted path of the host vehicle intersect with each other.

In addition, the ECU 26 determines that the oncoming vehicle has stopped when the longitudinal position Dy of the oncoming vehicle is smaller than the second threshold distance Dth2 and the target travel speed Vc of the oncoming vehicle is equal to or less than a predetermined third threshold speed Vth3. However, the ECU 26 may be configured to determine that the oncoming vehicle has stopped when the target travel speed Vc of the oncoming vehicle detected based on the forward image is equal to or less than the third threshold speed Vth3, regardless of the longitudinal position Dy.

In addition, the ECU 29 determines whether the first notification end condition is satisfied based on the steering speed Ws. However, the ECU 29 may be configured to determine that the first notification end condition is satisfied when the steering angle θs is smaller than a predetermined negative threshold angle θth in a left-hand traffic area. Alternatively, the ECU 29 may be configured to determine that the first notification end condition is satisfied when the steering angle θs is larger than a predetermined positive threshold angle θth in a right-hand traffic area. Furthermore, the ECU 29 may be configured to determine that the first notification end condition is satisfied based on a change in the yaw rate of the vehicle 10.

In addition, ECU 29 determines that the second notification end condition is met when the oncoming vehicle is no longer present. However, ECU 29 may be configured to determine that the second notification end condition is met when vehicle speed Vs is greater than a predetermined threshold speed. Alternatively, ECU 29 may be configured to determine whether the turn signal of the oncoming vehicle is activated (flashing) based on the forward image, and determine that the second notification end condition is met when it is determined that the turn signal of the oncoming vehicle is activated.

In addition, the third threshold speed Vth3 and the threshold operation amount Bth were both "0". However, one or both of the third threshold speed Vth3 and the threshold operation amount Bth may be a value greater than "0" (e.g., a small value).

In addition, in this embodiment and the modified example, the oncoming vehicle and the preceding vehicle are detected based on the forward image. That is, the oncoming vehicle and the preceding vehicle are detected using the forward camera 41. However, at least one of the oncoming vehicle and the preceding vehicle may be detected by a sensor other than the forward camera 41. For example, at least one of the oncoming vehicle and the preceding vehicle may be detected by a LiDAR (Laser Imaging Detection and Ranging) device or a millimeter wave radar device.

In addition, the functions realized by each of ECUs 21 to 29 in this embodiment may be realized by multiple ECUs. For example, the process of detecting a three-dimensional target based on a forward image may be executed by an ECU included in the forward camera 41.

10...vehicle, 21...vehicle control ECU, 41...forward camera, 42...turn signal lever sensor, 43...direction indicator, 43L...left indicator, 43R...right indicator, 44...vehicle speed sensor, 45...steering angle sensor, 46...display, 47...speaker, 48...speaker, 51...steering wheel, 51a...turn signal lever, 52...other vehicle, 61-67...other vehicle.

Claims (15)

a surroundings sensor that acquires surrounding information including information about targets present in a forward area of the vehicle and about marking lines on a road on which the vehicle is traveling;
a turn indicator whose state is changed from a non-operated state to an activated state by a predetermined operation by a driver of the vehicle;
an alarm that performs an alarm operation to notify the driver of the presence of another vehicle that the driver should be careful of;
A control unit for controlling the alarm;
In a vehicle notification device comprising:
The control unit
determining whether or not there is an oncoming vehicle, the oncoming vehicle being a vehicle traveling in an oncoming lane relative to the lane in which the host vehicle is traveling, approaching the host vehicle from in front of the host vehicle, and passing to the right of the host vehicle in areas where traffic is on the left and passing to the left of the host vehicle in areas where traffic is on the right ;
when it is determined that a specific direction indicator among the direction indicators, which is to the right of the host vehicle in areas where traffic is on the left and to the left of the host vehicle in areas where traffic is on the right, and which corresponds to a specific direction in which the host vehicle crosses the oncoming lane when turning right or left, is in the activated state and the host vehicle is present, based on at least one of information about a dividing line that divides the driving lane and which is included in a specific area that includes a part of an area through which the host vehicle will pass when turning in the specific direction and is predetermined for the host vehicle, and information about a preceding vehicle that is another vehicle located immediately before the host vehicle, causing the alarm to start the alarm operation when it is determined that a predetermined specific condition is established when it is predicted that the host vehicle is highly likely to start turning in the specific direction,
Even if it is determined that the specific direction indicator is in the operating state and that the oncoming vehicle is present, the notification device is not caused to start the notification operation while it is not determined that the specific condition is satisfied.
It was configured as follows:
Vehicle warning device. The vehicle notification device according to claim 1,
The control unit
determining whether a specific area condition is satisfied based on the surrounding information, the specific area being a condition that is satisfied when the specific area does not include a lane marking on the specific direction side of the pair of lane marks that define the driving lane;
determining that the specific condition is satisfied when it is determined that the specific area condition is satisfied;
It was configured as follows:
Vehicle warning device. The vehicle warning device according to claim 1,
The control unit
determining whether a turning waiting condition is satisfied based on the surrounding information, the turning waiting condition being satisfied when the specific area includes the lane marking on the specific direction side of the pair of lane marks defining the driving lane and the driving speed of the host vehicle is lower than a predetermined first threshold speed;
determining that the specific condition is satisfied when it is determined that the turning standby condition is satisfied;
It was configured as follows:
Vehicle warning device. The vehicle warning device according to claim 1,
The control unit
determining whether the preceding vehicle is present based on the surrounding information;
When it is determined that the preceding vehicle is present, it is determined whether or not the speed of the preceding vehicle is greater than a predetermined preceding vehicle turning threshold speed;
When it is determined that the speed of the preceding vehicle is greater than the preceding vehicle turning threshold speed, it is determined that the specific condition is established.
It was configured as follows:
Vehicle warning device. The vehicle warning device according to claim 1,
The control unit
determining whether the preceding vehicle is present based on the surrounding information;
When it is determined that the preceding vehicle is present, it is determined whether or not the preceding vehicle has started turning in the specific direction based on the surrounding information;
When it is determined that the preceding vehicle has started turning in the specific direction, it is determined that the specific condition is satisfied.
It was configured as follows:
Vehicle warning device. The vehicle warning device according to claim 1 or 2,
The control unit
determining whether or not there is a crossing vehicle, which is a vehicle different from the oncoming vehicle and whose predicted travel route intersects with the predicted travel route of the oncoming vehicle, based on the surrounding information;
When a prohibition condition including a condition that a crossing vehicle is present is satisfied, the execution of the notification operation is prohibited.
It was configured as follows:
Vehicle warning device. The vehicle warning device according to claim 1 or 2,
The control unit
determining whether or not there is a crossing vehicle, which is a vehicle different from the oncoming vehicle and whose predicted travel route intersects with the predicted route of the host vehicle, based on the surrounding information;
When a prohibition condition including a condition that a crossing vehicle is present is satisfied, the execution of the notification operation is prohibited.
It was configured as follows:
Vehicle warning device. The vehicle warning device according to claim 2,
The control unit
determining whether or not a lateral distance, which is a distance in a width direction of the host vehicle from the host vehicle to the oncoming vehicle, is equal to or greater than a lateral threshold distance, which increases as a traveling speed of the host vehicle increases, based on the surrounding information;
When a prohibition condition is satisfied, the execution of the announcing action is prohibited.
It was configured as follows:
Vehicle warning device. The vehicle warning device according to claim 2,
The control unit
When the traveling speed of the host vehicle is equal to or less than a fourth threshold speed, it is determined whether or not a lateral distance, which is a distance in a width direction of the host vehicle from the host vehicle to the oncoming vehicle, is equal to or greater than a third threshold distance, based on the surrounding information;
When a prohibition condition is satisfied, the prohibition condition includes a condition that the traveling speed of the host vehicle is equal to or less than the fourth threshold speed and the lateral distance is equal to or greater than the third threshold distance, the execution of the announcing operation is prohibited.
It was configured as follows:
Vehicle warning device. The vehicle warning device according to claim 9,
The control unit
When the traveling speed of the host vehicle is greater than the fourth threshold speed, it is determined whether the lateral distance is equal to or greater than a fourth threshold distance that is greater than the third threshold distance based on the surrounding information;
When a prohibition condition is satisfied, the prohibition condition includes a condition that the traveling speed of the host vehicle is higher than the fourth threshold speed and the lateral distance is equal to or greater than the fourth threshold distance, the execution of the notifying operation is prohibited.
It was configured as follows:
Vehicle warning device. The vehicle warning device according to claim 2,
a steering angle sensor for detecting an operation angle of a steering wheel of the host vehicle;
a brake pedal operation state sensor for detecting an operation state of a brake pedal of the host vehicle;
Equipped with
The control unit
The detected operation angle is a value in a direction opposite to a direction in which the host vehicle is turned so as to cross the oncoming lane , or the detected steering angle is a value in a direction in which the host vehicle is turned so as to cross the oncoming lane and the magnitude of the steering angle is smaller than a threshold angle, and
The detected brake pedal operation state indicates that the brake pedal is being operated, and
The traveling speed of the host vehicle is equal to or less than a fifth threshold speed.
Determine whether a prohibition condition is satisfied, including the condition
When the prohibition condition is satisfied, the execution of the notification action is prohibited.
It was configured as follows:
Vehicle warning device. The vehicle warning device according to claim 2,
The alarm includes a speaker that generates a sound and a display that displays a message.
The control unit
When it is determined that a longitudinal distance between the vehicle determined to be an oncoming vehicle and the own vehicle is smaller than a predetermined second threshold distance and a target traveling speed of the vehicle determined to be an oncoming vehicle is equal to or lower than a predetermined third threshold speed, it is determined that the vehicle determined to be an oncoming vehicle has stopped;
When it is determined that the vehicle that was determined to be the oncoming vehicle has stopped, a stop history indicating that it has been determined that the vehicle that was determined to be the oncoming vehicle has stopped is stored;
when it is determined that the specific condition is satisfied and the stop history is not stored, starting a notification operation using both the speaker and the display;
when it is determined that the specific condition is satisfied and the stop history is stored, starting an announcing operation using the speaker without using the display.
It was configured as follows:
Vehicle warning device. The vehicle warning device according to claim 2,
The control unit
When it is determined that a longitudinal distance between the vehicle determined to be an oncoming vehicle and the own vehicle is smaller than a predetermined second threshold distance and a target traveling speed of the vehicle determined to be an oncoming vehicle is equal to or lower than a predetermined third threshold speed, it is determined that the vehicle determined to be an oncoming vehicle has stopped;
When it is determined that the vehicle that was determined to be the oncoming vehicle has stopped, a stop history indicating that it has been determined that the vehicle that was determined to be the oncoming vehicle has stopped is stored;
When it is determined that the specific condition is satisfied and the stop history is not stored, the notification operation is started;
prohibiting the notification operation when the stop history is stored when it is determined that the specific condition is satisfied;
It was configured as follows:
Vehicle warning device. The notification device according to any one of claims 2 to 10,
a steering angle sensor for detecting an operation angle of a steering wheel of the vehicle;
The control unit
determining whether or not a predetermined first notification end condition is satisfied, the first notification end condition being satisfied when there is a high possibility that the host vehicle has stopped midway after starting to turn in the specific direction, based on a parameter corresponding to the detected steering angle;
When it is determined that the first notification end condition is satisfied during the execution of the notification action, the notification action is ended.
It was configured as follows:
Vehicle warning device. The notification device according to any one of claims 2 to 14,
The control unit
When a state in which it is determined that the oncoming vehicle does not exist continues for a third threshold time or more during the execution of the notification operation, the notification operation is terminated.
It was configured as follows:
Vehicle warning device.

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