JP7676864B2 - Driving Support Devices - Google Patents

Description

The present invention relates to a driving assistance device capable of performing blind spot avoidance control to prevent a vehicle from remaining in the blind spot of a vehicle traveling alongside for a long period of time while adaptive cruise control is being performed.

There have been known driving assistance devices capable of executing blind spot avoidance control while adaptive cruise control (hereinafter also simply referred to as "ACC") is being executed. For example, Patent Document 1 discloses a vehicle speed control device that performs blind spot avoidance control by controlling the vehicle speed so that the vehicle is positioned behind the blind spot area of a parallel vehicle when a "blind spot avoidance condition that is established when another vehicle traveling in an adjacent lane is a parallel vehicle" is established while ACC is being executed. Here, a parallel vehicle is defined as another vehicle traveling within a parallel running area set on an adjacent lane. The parallel running area is an area that is set near the vehicle based on the position of the vehicle.

JP 2019-073241 A

The ACC includes follow-up ACC and constant-speed ACC. Follow-up ACC controls the vehicle speed when there is a preceding vehicle so that the distance between the vehicle and the preceding vehicle is maintained at a predetermined set distance. Constant-speed ACC controls the vehicle speed when there is no preceding vehicle so that the vehicle travels at a predetermined set vehicle speed.

The vehicle speed control device of Patent Document 1 (hereinafter also referred to as the "conventional device") is configured to execute following ACC in priority over blind spot avoidance control when the vehicle distance to the preceding vehicle is greater than a predetermined avoidance release distance, even if the blind spot avoidance condition is met while following ACC is being executed (hereinafter also referred to as "Case 1"). In addition, the conventional device is configured to execute constant speed ACC in priority over blind spot avoidance control when the set vehicle speed is greater than the vehicle speed of the vehicle running alongside, even if the blind spot avoidance condition is met while constant speed ACC is being executed (hereinafter also referred to as "Case 2").

The conventional device configuration is described as being able to prevent a vehicle from remaining in the blind spot of a parallel vehicle for a long period of time while mitigating the discomfort felt by a driver who requests the execution of ACC (the discomfort caused by the vehicle being positioned behind the blind spot of a parallel vehicle for a long period of time due to blind spot avoidance control).

However, with conventional devices, there is a possibility that blind spot avoidance control may not be executed appropriately. That is, in case 1, the avoidance release distance is set as a distance at which "the vehicle can exit the blind spot area without the distance to the preceding vehicle becoming less than the set distance," so blind spot avoidance control is still executed (in preference to follow ACC) during the period from when the blind spot avoidance condition is met until the distance to the preceding vehicle becomes greater than the avoidance release distance. For this reason, even if the vehicle passes through the blind spot area in a relatively short time due to follow ACC, blind spot avoidance control is executed temporarily during the above period. It is difficult to say that such blind spot avoidance control achieves the original purpose of the control (the purpose of preventing the vehicle from remaining in the blind spot area for a long period of time), and it is an unnecessary operation.

In addition, in case 2, constant-speed ACC is executed even if the set vehicle speed is slightly faster than the vehicle speed of the vehicle traveling alongside. In this way, when the relative speed between the two is relatively low, it takes a certain amount of time for the vehicle to overtake the vehicle traveling alongside, so there is a possibility that the vehicle will remain in the blind spot area for a long period of time. Therefore, it is not desirable to give priority to constant-speed ACC even in such cases.

The present invention has been made to address the above-mentioned problems. That is, one of the objects of the present invention is to provide a driving assistance device that can appropriately execute blind spot avoidance control.

The driving assistance device according to the present invention (hereinafter referred to as the "device of the present invention") comprises:
The vehicle (1) is equipped with
a target information acquisition device (11) that detects other vehicles present around the vehicle (1) and marking lines extending in front of and behind the vehicle (1) and acquires information relating to the detected other vehicles and marking lines as target information;
A control unit (10) capable of acquiring lane information regarding whether a vehicle's own lane (40, 42) is an overtaking lane (40),
During a period in which adaptive cruise control is being executed, a position of a blind spot area (R) of a parallel running vehicle (2) that is another vehicle traveling in an adjacent lane (42, 40) is calculated based on the target information, and a predicted stay time (ts), which is a time during which the vehicle (1) is predicted to stay in the blind spot area (R), is calculated based on a relative speed (V2-V1) of the parallel running vehicle (2) with respect to the vehicle (1) and a positional relationship between the vehicle (1) and the blind spot area (R);
When the predicted stay time (ts) exceeds a predetermined stay time threshold (tsth), a blind spot avoidance control is performed in priority to the adaptive cruise control, the blind spot avoidance control being either an acceleration control for accelerating the vehicle (1) or a deceleration control for decelerating the vehicle (1);
When the predicted stay time (ts) is equal to or less than the stay time threshold (tsth), the blind spot avoidance control is not executed and the adaptive cruise control is continued ;
If the predicted stay time (ts) exceeds the stay time threshold (tsth), it is determined based on the target information whether or not there is a preceding vehicle traveling in the own lane (40, 42) ahead of the vehicle (1);
When a preceding vehicle space condition is satisfied, that is, the preceding vehicle does not exist, or the preceding vehicle exists but the inter-vehicle distance (D1) exceeds a predetermined first distance threshold (D1th),
When it is determined based on the lane information that the own lane (40, 42) is an overtaking lane (40), the acceleration control is executed as the blind spot avoidance control, and when it is determined that the own lane (40, 42) is not the overtaking lane (40), the deceleration control is executed as the blind spot avoidance control.
A control unit (10) configured as described above;
Equipped with.

The device of the present invention determines whether or not to execute blind spot avoidance control based on the predicted stay time. Specifically, when the predicted stay time is equal to or less than the stay time threshold, ACC is continued without executing blind spot avoidance control, and when the predicted stay time exceeds the stay time threshold, blind spot avoidance control is executed in preference to ACC. Therefore, when it is predicted that the vehicle will pass through the blind spot area quickly, the blind spot avoidance control is not executed, so that unnecessary operation of the control can be suppressed. In addition, when it is predicted that it will take a certain amount of time for the vehicle to pass through the blind spot area, the blind spot avoidance control is executed regardless of the speed relationship between the vehicle and the vehicle running alongside, so that the occurrence of a situation in which the control is not executed when the control is necessary can be suppressed. As a result, the device of the present invention can appropriately execute the blind spot avoidance control.
In addition, when the predicted dwell time exceeds the dwell time threshold and the preceding vehicle space condition is satisfied, the device of the present invention executes acceleration control if the vehicle's lane is an overtaking lane, and executes deceleration control if the vehicle's lane is not an overtaking lane. With this configuration, when the vehicle is traveling in the overtaking lane, acceleration control is executed, so that the vehicle can quickly pass through the blind spot area. On the other hand, when the vehicle is traveling in a lane other than the overtaking lane (i.e., the driving lane), deceleration control is executed, so that the vehicle can quickly pass through the blind spot area without impeding the overtaking of other vehicles (including vehicles traveling parallel to each other) traveling in the overtaking lane.

In one aspect of the invention,
The deceleration control includes a first deceleration control and a second deceleration control,
The magnitude of the target deceleration of the first deceleration control is greater than the magnitude of the target deceleration of the second deceleration control,
The control unit (10)
If the preceding vehicle space condition is not met,
Regardless of whether the lane is an overtaking lane (40) or a driving lane (42),
When a following vehicle space condition is satisfied, that is, when there is no following vehicle traveling in the own lane behind the vehicle (1), or when a following vehicle is present but its inter-vehicle distance (D2) exceeds a predetermined second distance threshold (D2th), the first deceleration control is executed, and when the following vehicle space condition is not satisfied, the second deceleration control is executed.
It is structured as follows.

According to this configuration, when the preceding vehicle space condition is not satisfied (i.e., when a preceding vehicle is present and the first inter-vehicle distance is equal to or less than the first distance threshold), if the vehicle's lane is an overtaking lane and the following vehicle space condition is satisfied, the first deceleration control is executed. Therefore, when a blind spot area exists behind the vehicle, the relative speed of the vehicle traveling parallel to the vehicle increases, and the vehicle can pass through the blind spot area quickly. In addition, when the preceding vehicle space condition is not satisfied, if the vehicle's lane is an overtaking lane and the following vehicle space condition is not satisfied, the second deceleration control is executed. Therefore, the relative speed of the vehicle traveling parallel to the vehicle increases gradually, and the vehicle can pass through the blind spot area relatively quickly, and the impact on the traveling of the following vehicle due to deceleration can be suppressed.
Furthermore, according to this configuration, when the preceding vehicle space condition is not satisfied and the host vehicle is in the driving lane, the first deceleration control is executed when the following vehicle space condition is satisfied, and the second deceleration control is executed when the following vehicle space condition is not satisfied, thereby making it possible to suppress the occurrence of a situation in which the host vehicle obstructs the driving of a vehicle (and other vehicles) traveling alongside in the overtaking lane.

In the above explanation, to aid in understanding the invention, the symbols used in the embodiments are enclosed in parentheses with respect to the constituent elements of the invention corresponding to the embodiments, but each constituent element of the invention is not limited to the embodiment defined by the symbols.

1 is a schematic configuration diagram of a driving assistance device according to an embodiment of the present invention (present implementation device). FIG. 1 is a diagram showing a situation in which the host vehicle is traveling in the passing lane at a higher speed than a vehicle traveling alongside the host vehicle. FIG. 1 is a diagram showing a situation in which the host vehicle is traveling in the passing lane at a slower speed than a vehicle traveling alongside the host vehicle; FIG. 1 is a diagram showing a situation in which the host vehicle is traveling in a traffic lane at a higher speed than a vehicle traveling alongside the host vehicle; FIG. 1 is a diagram showing a situation in which the host vehicle is traveling in a traffic lane at a slower speed than a vehicle traveling alongside the host vehicle. 4 is a flowchart showing a routine executed by a CPU of a driving assistance ECU of the embodiment of the present invention.

(composition)
Hereinafter, a driving assistance device according to an embodiment of the present invention (hereinafter also referred to as "the embodiment device") will be described with reference to the drawings. The embodiment device is mounted on a vehicle. As shown in FIG. 1, the embodiment device includes a driving assistance ECU 10. The driving assistance ECU 10 includes a microcomputer as a main part. ECU is an abbreviation for Electronic Control Unit. The microcomputer includes a CPU, a ROM, a RAM, an interface (I/F), etc., and the CPU is configured to realize various functions by executing instructions (programs, routines) stored in the ROM. Hereinafter, the vehicle on which the embodiment device is mounted will be referred to as the "own vehicle."

The driving assistance ECU 10 is connected to an ambient sensor 11, a vehicle speed sensor 12, and a navigation system 13, and is configured to acquire signals output or generated by these sensors or systems at each predetermined calculation period. Hereinafter, the driving assistance ECU 10 is also referred to simply as "ECU 10."

The surroundings sensor 11 (target information acquisition device) includes a camera sensor and a radar sensor.
The camera sensor includes a front camera sensor installed on the back of the room mirror (inner mirror/rearview mirror) of the host vehicle, and a rear camera sensor installed on the rear glass of the host vehicle. The front camera sensor captures the scenery in front of the host vehicle (specifically, from the front to the diagonally forward), and the rear camera sensor captures the scenery behind the host vehicle (specifically, from the rear to the diagonally rear). The camera sensor recognizes (detects) other vehicles existing around the host vehicle based on image data captured by the front and rear camera sensors, respectively, and calculates the relative relationship between the host vehicle and the other vehicles. Here, the "relative relationship between the host vehicle and the other vehicles" includes the distance from the host vehicle to the other vehicles, the direction and relative speed of the other vehicles relative to the host vehicle, etc.

In addition, the camera sensor recognizes (detects) lane markings extending in front of and behind the vehicle based on the image data. Ladder marks are lines marked on the road to divide vehicle traffic into different directions. The camera sensor calculates the shape of the lane based on the recognized lane marks. Note that a lane is defined as the area between two adjacent lane marks extending on the roadway. The camera sensor is capable of recognizing the lane marks that make up the vehicle's own lane (the lane in which the vehicle is currently traveling) and adjacent lanes (lanes adjacent to the vehicle's own lane on either the left or right).

The radar sensor includes a front radar sensor installed at the left and right corners of the front bumper of the vehicle, and a rear radar sensor installed at the left and right corners of the rear bumper of the vehicle. The front radar sensor irradiates millimeter wave band radio waves from the front to the sides of the vehicle, and the rear radar sensor irradiates millimeter wave band radio waves from the rear to the sides of the vehicle. If another vehicle is present, the radar sensor receives reflected waves from the other vehicle. The radar sensor recognizes (detects) other vehicles present around the vehicle based on the timing of radio wave irradiation and reception, etc., and calculates the relative relationship between the vehicle and the other vehicles.

The surrounding sensor 11 acquires information about the other vehicles and lane markings detected as target information, and outputs the acquired target information to the ECU 10.

The vehicle speed sensor 12 generates a signal corresponding to the traveling speed (vehicle speed) of the vehicle. The ECU 10 acquires the signal generated by the vehicle speed sensor 12 and calculates the vehicle speed based on the signal.

The navigation system 13 includes a navigation ECU, and a GPS receiver and a map database connected thereto. The GPS receiver receives a GPS signal for detecting the current position of the vehicle. The map database stores map information. The navigation ECU identifies the current position of the vehicle based on the GPS signal transmitted from the GPS receiver every time a predetermined time elapses. Then, based on the identified position of the vehicle and the map information stored in the map database, it performs various calculations to determine whether the vehicle's lane is an overtaking lane, and outputs the determination result to the ECU 10 as lane information.

The ECU 10 is connected to the drive unit 20 and the brake unit 30. The ECU 10 executes various controls (in this embodiment, ACC and blind spot avoidance control (both described below)) by controlling the drive unit 20 and the brake unit 30 based on the target object information and the lane information. Strictly speaking, the lane information is used only when necessary (only when the preceding vehicle space condition described below is satisfied).

The drive unit 20 is a device for applying a driving force to the drive wheels of the vehicle to make the vehicle run. Since the vehicle is a hybrid vehicle, the drive source of the drive unit 20 is an engine and a motor. The ECU 10 controls the operation of the drive unit 20 to control the driving force applied to the drive wheels.

The braking device 30 is a device for applying a braking force to the wheels of the vehicle to brake the vehicle. The ECU 10 controls the operation of the braking device 30 to control the braking force applied to the wheels.

(Details of operation)
In general, when the vehicle is traveling at a constant speed due to ACC, the vehicle may remain in the blind spot area of the vehicle traveling alongside for a long period of time depending on the positional relationship between the vehicle and the vehicle. For this reason, in the past, when there is a possibility that the above-mentioned situation may occur while ACC is being performed, blind spot avoidance control has been performed in preference to ACC. However, in the conventional configuration, the conditions for performing the blind spot avoidance control have not been sufficiently considered, so that while the blind spot avoidance control is performed at a timing when the control is not necessary, the control may not be performed at a timing when the control is necessary.

Therefore, the ECU 10 is configured to calculate a predicted stay time ts (the time the vehicle is predicted to stay in the blind spot) before the vehicle enters the blind spot area, and to determine whether or not to execute blind spot avoidance control based on the predicted stay time ts. A detailed explanation will be given below with reference to Figures 2A to 3B, but first a brief explanation of ACC will be given.

ACC can be started by the driver of the vehicle. That is, this embodiment device is equipped with an ACC switch and a vehicle distance/vehicle speed changeover switch (not shown). These switches are provided near the driver's seat and can be operated by the driver of the vehicle. When the ACC switch is turned on, an ACC request signal is sent to the ECU 10. When the ECU 10 receives the ACC request signal, it determines whether or not there is a preceding vehicle (another vehicle traveling in the vehicle's lane ahead of the vehicle) based on the target information.

When it is determined that a preceding vehicle exists, the ECU 10 executes the following ACC. At this time, the ECU 10 determines the following distance that is preset by the following distance/vehicle speed changeover switch as the set following distance. The set following distance can be switched to three types, "long", "medium" and "short", by operating the following distance/vehicle speed changeover switch.
On the other hand, if it is determined that there is no preceding vehicle, the ECU 10 executes constant speed ACC. At this time, the ECU 10 determines the vehicle speed that is preset by the following distance/vehicle speed changeover switch as the set vehicle speed. The set vehicle speed can be changed to a vehicle speed within a predetermined vehicle speed range by operating the following distance/vehicle speed changeover switch. This concludes the explanation of ACC.

When calculating the predicted stay time ts, the ECU 10 first identifies the parallel running vehicle and calculates (estimates) the position of the blind spot area of the identified parallel running vehicle (more precisely, the position coordinates of the outline of the blind spot area). Here, a blind spot area is an area where it is difficult for the driver of the parallel running vehicle to check the surrounding situation using the side mirror. Blind spot areas can exist on both the left and right sides of the parallel running vehicle, but the ECU 10 only calculates the position of blind spot areas that exist in the own lane.

2A and 2B show a situation in which the host vehicle 1 performing ACC is traveling in the passing lane 40, and the other vehicle 2 is traveling in the driving lane 42. That is, the passing lane 40 is the host lane, and the driving lane 42 is the adjacent lane. In FIG. 2A, the vehicle speed V1 of the host vehicle 1 is higher than the vehicle speed V2 of the other vehicle 2 (V1>V2), and in FIG. 2B, the vehicle speed V1 is lower than the vehicle speed V2 (V1<V2). On the other hand, FIG. 3A and 3B show a situation in which the host vehicle 1 performing ACC is traveling in the driving lane 42, and the other vehicle 2 is traveling in the passing lane 40. That is, the driving lane 42 is the host lane, and the passing lane 40 is the adjacent lane. In FIG. 3A, the vehicle speed V1 is higher than the vehicle speed V2 (V1>V2), and in FIG. 3B, the vehicle speed V1 is lower than the vehicle speed V2 (V1<V2).
While ACC is being executed, the ECU 10 identifies another vehicle 2 traveling in the adjacent lane 42 (or 40) as a parallel vehicle based on target object information output from the surrounding sensor 11, and calculates the position of the blind spot area R of the parallel vehicle 2.

2A to 3B, the blind spot area R is rectangular and has short sides extending in the short direction and long sides extending in the long direction. The short sides are approximately parallel to the vehicle width direction of the parallel vehicle 2 and are set to a length equivalent to the lane width of the vehicle's lane 40 (or 42). The long sides are approximately parallel to the front-rear direction (direction perpendicular to the vehicle width direction) of the parallel vehicle 2. In the following, for ease of explanation, the short side of the blind spot area R that is closest to the vehicle 1 will be referred to as the "entrance Ri of the blind spot area R" or "entrance Ri", and the short side that is farther away from the vehicle 1 will be referred to as the "exit Ro of the blind spot area R" or "exit Ro".

When the parallel running vehicle 2 is present in front of the vehicle 1 (see Figures 2A and 3A), the ECU 10 determines "the length d1 from a straight line L1 that passes through the rear end of the parallel running vehicle 2 and is parallel to the vehicle width direction to the entrance Ri of the blind spot area R" and "the length d2 from the straight line L1 to the exit Ro of the blind spot area R" based on the overall length of the parallel running vehicle 2. Specifically, the ECU 10 increases the lengths d1 and d2 as the length of the parallel running vehicle 2 increases. This determines the position of the blind spot area R (the relative position with respect to the parallel running vehicle 2). The overall length of the parallel running vehicle 2 can be calculated based on the target information.

On the other hand, when the parallel running vehicle 2 is present behind the vehicle 1 (see Figures 2B and 3B), the ECU 10 determines "the length d3 from the straight line L2 that passes through the front end of the parallel running vehicle 2 and is parallel to the vehicle width direction to the entrance Ri of the blind spot area R" and "the length d4 from the straight line L2 to the exit Ro of the blind spot area R" based on the overall length of the parallel running vehicle 2. Specifically, the ECU 10 makes the lengths d3 and d4 longer as the length of the parallel running vehicle 2 becomes longer. This determines the position of the blind spot area R.

Next, the ECU 10 calculates the time (entrance arrival time) ti that is predicted to be required for the host vehicle 1 to reach the entrance Ri of the blind spot area R (i.e., to enter the blind spot area R). In the case of Figs. 2A and 3A, the entrance arrival time ti can be calculated by dividing the "value obtained by subtracting the length d1 from the distance from the host vehicle 1 to the other vehicle 2 (strictly speaking, the distance from the front end P1 of the host vehicle 1 to the straight line L1)" by the "magnitude of the relative speed of the parallel vehicle 2 with respect to the host vehicle 1 |V2-V1|". On the other hand, in the case of Figs. 2B and 3B, the entrance arrival time ti can be calculated by dividing the "value obtained by adding the length d3 to the distance from the host vehicle 1 to the other vehicle 2 (strictly speaking, the distance from the rear end P2 of the host vehicle 1 to the straight line L2)" by the "magnitude of the relative speed |V2-V1|".

The ECU 10 determines whether the entrance arrival time ti is equal to or less than a predetermined arrival time threshold tith. If it is determined that ti>tith holds, the ECU 10 determines that the possibility that the host vehicle 1 will enter the blind spot area R in the near future is relatively low, and continues ACC without executing blind spot avoidance control. On the other hand, if it is determined that ti≦tith holds, the ECU 10 determines that the possibility that the host vehicle 1 will enter the blind spot area R in the near future is relatively high, and calculates the predicted stay time ts.

When calculating the predicted staying time ts, the ECU 10 calculates the time (exit arrival time) to that is predicted to be required for the host vehicle 1 to reach the exit Ro of the blind spot area R. Then, the ECU 10 calculates the predicted staying time ts by subtracting the entrance arrival time ti from the exit arrival time to. In the case of FIG. 2A and FIG. 3A, the exit arrival time to can be calculated by dividing the "value (value 1) obtained by adding the length d2 to the distance from the host vehicle 1 to the other vehicle 2" by the "magnitude of the relative speed |V2-V1|". On the other hand, in the case of FIG. 2B and FIG. 3B, the exit arrival time to can be calculated by dividing the "value (value 2) obtained by adding the length d4 to the distance from the host vehicle 1 to the other vehicle 2" by the "magnitude of the relative speed |V2-V1|".

The exit arrival time to may be calculated by dividing the "value obtained by adding the overall length of the vehicle 1 to value 1 or value 2" by the "magnitude of the relative speed |V2-V1|". The predicted stay time ts may be calculated by dividing the "length of the blind spot area R in the longitudinal direction (i.e., d1+d2 in the case of Figures 2A and 3A, and d4-d3 in the case of Figures 2B and 3B) (value 3)" by the "magnitude of the relative speed |V2-V1|", or by dividing the "value obtained by adding the overall length of the vehicle 1 to value 3" by the "magnitude of the relative speed |V2-V1|".

If multiple parallel vehicles are detected, the ECU 10 calculates the entrance arrival time ti of each parallel vehicle to the blind spot R, and calculates the predicted stay time ts for the parallel vehicle with the shortest entrance arrival time ti.

The ECU 10 judges whether the predicted stay time ts exceeds a predetermined stay time threshold tsth. If it is judged that ts≦tsth holds, the ECU 10 judges that the host vehicle 1 is predicted to pass through the blind spot area R relatively quickly, and therefore no adverse effects will occur due to the host vehicle remaining in the blind spot area R for a long period of time, and continues ACC without executing blind spot avoidance control. On the other hand, if it is judged that ts>tsth holds, the ECU 10 judges that the host vehicle 1 is predicted to take a certain amount of time to pass through the blind spot area R, and therefore there is a high probability that the above-mentioned adverse effects will occur, and executes blind spot avoidance control in preference to ACC.

In this way, the present implementation device determines whether or not to execute blind spot avoidance control based on the predicted stay time ts. Therefore, even if there is a high possibility that the host vehicle 1 will enter the blind spot area R in the near future, blind spot avoidance control will not be executed when it is predicted that the host vehicle 1 will quickly pass through the blind spot area R. This makes it possible to suppress unnecessary operation of blind spot avoidance control. On the other hand, according to the present implementation device, blind spot avoidance control is executed when it is predicted that it will take a certain amount of time to pass through the blind spot area R, regardless of the speed relationship between the host vehicle 1 and the parallel running vehicle 2. This makes it possible to suppress the occurrence of a situation in which blind spot avoidance control does not operate when it is necessary. As a result, blind spot avoidance control can be executed appropriately.

The stay time threshold tsth is a variable value that changes according to the vehicle speed V1, and is configured to become larger as the vehicle speed V1 decreases (i.e., it becomes more difficult for ts>tsth to be satisfied). As a result, even if the host vehicle 1 and the parallel vehicle 2 are caught in a traffic jam and the predicted stay time ts increases significantly, the stay time threshold tsth increases as the vehicle speed V1 decreases, making it difficult for the predicted stay time ts to exceed the stay time threshold tsth. Therefore, unnecessary operation of the blind spot avoidance control can be more reliably suppressed. Note that when the vehicle speed V1 is relatively high (for example, exceeding 80 [km/h]), the host vehicle 1 is predicted to cruise at a constant vehicle speed while ACC is being executed, so even if the stay time threshold tsth becomes smaller, it is possible to accurately determine whether ts>tsth is satisfied.

Next, the blind spot avoidance control will be described. The ECU 10 executes the following three types of control as the blind spot avoidance control: acceleration control, first deceleration control, and second deceleration control. The magnitude of the target deceleration in the first deceleration control is greater than the magnitude of the target deceleration in the second deceleration control. In other words, the second deceleration control decelerates the vehicle speed more slowly than the first deceleration control. Hereinafter, the first deceleration control and the second deceleration control may be collectively referred to as "deceleration control."

When the vehicle 1 is traveling in the overtaking lane 40 (in other words, the vehicle's lane is the overtaking lane 40) (see Figures 2A and 2B), and the preceding vehicle space condition is satisfied, the ECU 10 executes acceleration control as blind spot avoidance control. Here, the preceding vehicle space condition includes a condition that there is no preceding vehicle, or, even if there is a preceding vehicle, the inter-vehicle distance D1 exceeds a predetermined first distance threshold D1th (in other words, a condition that there is sufficient space ahead of the vehicle 1), and whether or not the preceding vehicle space condition is satisfied can be determined based on target object information. In addition, whether or not the vehicle 1 is traveling in the overtaking lane 40 can be determined based on lane information.

When a blind spot area R exists ahead of the host vehicle 1 (see FIG. 2A), acceleration control is executed at least until the host vehicle 1 passes through the blind spot area R. The first distance threshold D1th is a value that prevents the host vehicle 1 from getting too close to the preceding vehicle when the acceleration control is ended, and is configured to become larger as the vehicle speed V1 increases. The first distance threshold D1th can be determined in advance by experiment or simulation.

The ECU 10 controls the drive device 20 to execute acceleration control. Specifically, the ECU 10 calculates a target acceleration based on the vehicle speed V1, the predicted stay time ts, and, if there is a preceding vehicle, the vehicle distance D1, and calculates the driving force (required driving force) required to make the current acceleration match the target acceleration. Then, it determines whether to drive the engine or the motor according to the required driving force. That is, in general, when the required driving force is large, the engine operates more efficiently than the motor, and when the required driving force is small, the motor operates more efficiently than the engine. Therefore, the ECU 10 selects a driving source that operates more efficiently according to the required driving force, and controls the drive device 20 so that the required driving force is applied to the host vehicle 1 by the selected driving source. This allows the acceleration control to be executed efficiently (with low fuel consumption).

When a blind spot area R exists in front of the host vehicle 1 (see FIG. 2A), acceleration control is executed to increase the relative speed of the host vehicle 1 with respect to the parallel vehicle 2, allowing the host vehicle 1 to quickly pass through the blind spot area R. On the other hand, when a blind spot area R exists behind the host vehicle 1 (see FIG. 2B), acceleration control is executed to make it difficult for the parallel vehicle 2 to catch up with the host vehicle 1, making it difficult for the host vehicle 1 to enter the blind spot area R. In other words, in either case, it is possible to avoid the host vehicle 1 remaining in the blind spot area R for a long period of time.

Here, although the vehicle speed V1 increases during the execution of the acceleration control, the control is only executed temporarily, so it is considered that the driver is unlikely to feel discomfort due to the acceleration control. In other words, the present implementation device prioritizes avoiding the adverse effects caused by staying in the blind spot area R for a long period of time over the slight discomfort caused by a temporary increase in the vehicle speed V1. Note that, when the execution conditions for the acceleration control are met, the ECU 10 may be configured to suggest to the driver that the vehicle speed V1 be increased, rather than immediately executing the acceleration control, and to execute the acceleration control when the driver approves the suggestion. The suggestion is made, for example, by displaying the increase in the vehicle speed V1 on a display (for example, a display for displaying a map provided in the navigation system 13). The permission is given, for example, by the driver touching a permission button displayed on the display. This can reduce the discomfort mentioned above. Note that the increase in the vehicle speed V1 is, for example, 10 [km/h].

On the other hand, when the vehicle 1 is traveling in the passing lane 40 (see FIG. 2A and FIG. 2B), if the preceding vehicle space condition is not satisfied (i.e., if a preceding vehicle exists and the distance D1 between the preceding vehicle and the preceding vehicle is equal to or less than the first distance threshold D1th), the ECU 10 executes deceleration control as blind spot avoidance control. Specifically, the ECU 10 executes the first deceleration control when the following vehicle space condition is satisfied, and executes the second deceleration control when the condition is not satisfied. Here, the following vehicle space condition includes a condition that a following vehicle (another vehicle traveling in the vehicle lane behind the vehicle 1) does not exist, or, even if a following vehicle exists, the distance D2 between the preceding vehicle and the preceding vehicle exceeds a predetermined second distance threshold D2th (in other words, a condition that there is sufficient space behind the vehicle 1), and whether or not the following vehicle space condition is satisfied can be determined based on the target information. The second distance threshold D2th is configured to be larger as the vehicle speed V1 increases, and can be determined in advance by experiment or simulation.

The ECU 10 controls the braking device 30 to execute deceleration control. Specifically, the ECU 10 calculates a target deceleration based on the vehicle speed V1, the predicted dwell time ts, and, if there is a following vehicle, the following distance D2, and calculates the braking force (required braking force) required to make the current acceleration (including deceleration that is negative acceleration) match the target deceleration. The ECU 10 preferentially utilizes the braking force generated by the regenerative brake of the motor, and when the regenerative brake alone is insufficient, drives the brake actuator to generate frictional braking force, thereby controlling the braking device 30 so that the required braking force is applied to the host vehicle 1.

When a blind spot area R exists behind the host vehicle 1 (see FIG. 2B ), the first deceleration control is executed to increase the relative speed of the parallel running vehicle 2 with respect to the host vehicle 1, so that the host vehicle 1 can quickly pass through the blind spot area R. In addition, in this case, the second deceleration control is executed to gradually increase the relative speed of the parallel running vehicle 2 with respect to the host vehicle 1, so that the host vehicle 1 can pass through the blind spot area R relatively quickly and can suppress the deceleration from affecting the driving of the following vehicle.
On the other hand, when a blind spot area R exists ahead of the host vehicle 1 (see FIG. 2A ), the first deceleration control is executed, so that the host vehicle 1 has difficulty catching up with the parallel running vehicle 2, and therefore the host vehicle 1 has difficulty entering the blind spot area R. In addition, in this case, the second deceleration control is executed to slow down the rate at which the host vehicle 1 catches up with the parallel running vehicle 2, so that the host vehicle 1 has difficulty immediately entering the blind spot area R, and it is possible to suppress the deceleration from affecting the driving of the following vehicle.

In addition, when the vehicle 1 is traveling in the driving lane 42 (in other words, the vehicle 1 is a lane other than the passing lane 40) (see FIG. 3A and FIG. 3B), the ECU 10 does not execute acceleration control regardless of whether the preceding vehicle space condition is satisfied, but executes deceleration control as blind spot avoidance control. Specifically, the ECU 10 executes the first deceleration control when the following vehicle space condition is satisfied, and executes the second deceleration control when the condition is not satisfied. This is to avoid interfering with the traveling of the parallel vehicle 2 (and other vehicles) traveling in the passing lane 40. That is, the parallel vehicle 2 is traveling in the passing lane 40 to overtake a vehicle (including the vehicle 1) traveling in the driving lane 42, and is considered to change lanes to the driving lane 42 after completing the overtaking. At this time, if the vehicle 1 accelerates by the acceleration control, the parallel vehicle 2 may not be able to overtake the vehicle and may interfere with the lane change to the driving lane 42. Therefore, when the vehicle 1 is traveling in the travel lane 42, the ECU 10 is configured to only perform deceleration control.

When a blind spot area R exists behind the vehicle 1 (see FIG. 3B), the effect is the same as when deceleration control is executed when the vehicle 1 is traveling in the passing lane 40. Also, when a blind spot area R exists in front of the vehicle 1 (see FIG. 3A), the effect is the same as when deceleration control is executed when the vehicle 1 is traveling in the passing lane 40.

(Specific operation)
Next, a specific operation of the CPU of the ECU 10 will be described. The CPU is configured to repeatedly execute a routine shown in the flowchart of FIG.

At a predetermined timing, the CPU starts processing from step 400 in FIG. 4 and proceeds to step 405 to determine whether or not the host vehicle 1 is executing ACC. If ACC is not being executed, the CPU determines "No" in step 405, proceeds to step 495, and ends this routine. On the other hand, if ACC is being executed, the CPU determines "Yes" in step 405, and proceeds to step 410.

In step 410, the CPU identifies the parallel running vehicle 2 based on the target information output from the surrounding sensor 11, and calculates the position of its blind spot area R. Then, the CPU calculates the entrance arrival time ti of the blind spot area R, and determines whether the time ti is equal to or less than the arrival time threshold tith. If ti > tith is true, the CPU determines "No" in step 410, proceeds to step 495, and ends this routine. On the other hand, if ti ≦ tith is true, the CPU determines "Yes" in step 410, and proceeds to step 415.

In step 415, the CPU calculates the predicted stay time ts in the blind spot area R based on the target information, and determines whether the time ts exceeds the stay time threshold value tsth. If ts≦tsth holds, the CPU determines "No" in step 415, proceeds to step 495, and ends this routine. On the other hand, if ts>tsth holds, the CPU determines "Yes" in step 415, and proceeds to step 420.

In step 420, the CPU determines whether or not a preceding vehicle exists based on the target object information. If a preceding vehicle does not exist, the CPU determines "No" in step 420 (i.e., determines that the preceding vehicle space condition is met) and proceeds directly to step 430 without passing through step 425. On the other hand, if a preceding vehicle exists, the CPU determines "Yes" in step 420 and proceeds to step 425. In step 425, the CPU determines whether the inter-vehicle distance D1 to the preceding vehicle exceeds the first distance threshold D1th. If D1>D1th is met, the CPU determines "Yes" in step 425 (i.e., determines that the preceding vehicle space condition is met) and proceeds to step 430.

In step 430, the CPU determines whether or not the host vehicle 1 is traveling in the passing lane 40 based on the lane information output from the navigation system 13. If the host vehicle 1 is traveling in the passing lane 40, the CPU determines "Yes" in step 430 and proceeds to step 435. In step 435, the CPU executes acceleration control as blind spot avoidance control, prioritizing ACC. After that, the CPU proceeds to step 495 and temporarily ends this routine.

In contrast, if D1≦D1th is true in step 425, the CPU determines "No" in step 425 (i.e., determines that the preceding vehicle space condition is not true) and proceeds to step 440. On the other hand, if the host vehicle 1 is traveling in a lane other than the overtaking lane (traveling lane 42) in step 430, the CPU determines "No" in step 430 (i.e., determines that the space condition is true but the host lane is not the overtaking lane 40) and proceeds to step 440.

In step 440, the CPU determines whether or not a following vehicle is present based on the target object information. If a following vehicle is not present, the CPU determines "No" in step 440 (i.e., determines that the following vehicle space condition is met) and proceeds directly to step 450 without passing through step 445. On the other hand, if a following vehicle is present, the CPU determines "Yes" in step 440 and proceeds to step 445. In step 445, the CPU determines whether the inter-vehicle distance D2 from the following vehicle exceeds the second distance threshold D2th. If D2>D2th is met, the CPU determines "Yes" in step 445 (i.e., determines that the following vehicle space condition is met) and proceeds to step 450.

In step 450, the CPU executes the first deceleration control as blind spot avoidance control, prior to ACC. The CPU then proceeds to step 495 and ends this routine. On the other hand, if D2≦D2th is true, the CPU determines "No" in step 445 (i.e., determines that the following vehicle space condition is not true) and proceeds to step 455. In step 455, the CPU executes the second deceleration control as blind spot avoidance control, prior to ACC. The CPU then proceeds to step 495 and ends this routine.

The above describes the driving assistance device according to this embodiment, but the present invention is not limited to the above embodiment, and various modifications are possible without departing from the purpose of the present invention.

10: Driving assistance ECU, 11: Surrounding sensor, 12: Vehicle speed sensor, 13: Navigation system, 20: Drive system, 30: Braking system

Claims (2)

It is mounted on the vehicle,
a target information acquisition device that detects other vehicles present around the vehicle and marking lines extending in front of and behind the vehicle, and acquires information relating to the detected other vehicles and marking lines as target information;
A control unit capable of acquiring lane information regarding whether the vehicle's lane is an overtaking lane,
while adaptive cruise control is being executed, a position of a blind spot area of a parallel running vehicle that is another vehicle traveling in an adjacent lane is calculated based on the target information, and a predicted stay time that is a time that the vehicle is predicted to stay in the blind spot area is calculated based on a relative speed of the parallel running vehicle with respect to the vehicle and a positional relationship between the vehicle and the blind spot area;
When the predicted dwell time exceeds a predetermined dwell time threshold, a blind spot avoidance control that performs either an acceleration control for accelerating the vehicle or a deceleration control for decelerating the vehicle is executed in priority to the adaptive cruise control;
When the predicted stay time is equal to or less than the stay time threshold, the blind spot avoidance control is not executed and the adaptive cruise control is continued ;
If the predicted stay time exceeds the stay time threshold, it is determined based on the target information whether or not a preceding vehicle, which is another vehicle traveling in the own lane ahead of the vehicle, is present;
When a preceding vehicle space condition is satisfied, that is, the preceding vehicle is not present, or the preceding vehicle is present but the inter-vehicle distance exceeds a predetermined first distance threshold,
When it is determined based on the lane information that the own lane is an overtaking lane, the acceleration control is executed as the blind spot avoidance control, and when it is determined that the own lane is not the overtaking lane, the deceleration control is executed as the blind spot avoidance control.
A control unit configured as described above.
Equipped with
Driving assistance device. The driving assistance device according to claim 1,
The deceleration control includes a first deceleration control and a second deceleration control,
The magnitude of the target deceleration of the first deceleration control is greater than the magnitude of the target deceleration of the second deceleration control,
The control unit
If the preceding vehicle space condition is not met,
Regardless of whether the lane is an overtaking lane or a driving lane,
When a following vehicle space condition is satisfied, that is, when there is no following vehicle traveling in the own lane behind the vehicle, or when there is a following vehicle but the distance between the following vehicle exceeds a predetermined second distance threshold, the first deceleration control is executed, and when the following vehicle space condition is not satisfied, the second deceleration control is executed.
It was configured as follows:
Driving assistance device.

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