JP7687045B2 - Driving Support Devices - Google Patents

Description

The present invention relates to a driving assistance device that obtains a target vehicle speed according to the degree of curvature of a curved road on which the vehicle is traveling, and controls the acceleration/deceleration of the vehicle so that the acceleration/deceleration of the vehicle matches the target acceleration/deceleration obtained based on the target vehicle speed.

Conventionally, driving assistance devices are known that perform control (hereinafter, speed management control (SPM control)) for a vehicle to travel on a curved road at a target vehicle speed according to the curvature of the curved road. For example, the driving assistance device described in Patent Document 1 (hereinafter, referred to as the "conventional device") obtains a target vehicle speed based on the turning radius and road surface μ value of the curved road, and performs SPM control based on this target vehicle speed. More specifically, the conventional device obtains a smaller target vehicle speed the larger the turning radius (i.e., the larger (steeper) the curvature of the curved road), and obtains a smaller target vehicle speed the smaller the road surface μ value.

JP 2004-230946 A

However, the level of anxiety that a driver feels that the vehicle may deviate from the lane it is currently traveling in when traveling on a curved road (departure anxiety) also varies depending on the environment other than the road surface μ value surrounding the lane in which the vehicle is traveling. The following two environments are mainly considered to be environments in which such departure anxiety increases.
(1) On a curved road with a narrow shoulder, the vehicle is more likely to go over the shoulder if it deviates from its lane, so the anxiety of deviation is greater than on a curved road with a wide shoulder.
(2) On curved roads where the height of roadside objects (guardrails, fences, curbs, etc. installed along the lanes) is low, there is a higher possibility that the vehicle will go over the roadside object if it deviates from the lane, compared to curved roads where the height of the roadside objects is high, which increases the anxiety of deviation from the lane.
In such an environment where the anxiety of deviation from the normal road increases, the driver has a marked tendency to desire the vehicle to travel on the curved road at a slower vehicle speed.

The above-mentioned conventional devices do not take into account the environment other than the road surface μ value, so in an environment where the above-mentioned departure anxiety is high, the vehicle may not be able to travel on a curved road at an appropriate vehicle speed desired by the driver, which may cause departure anxiety for the driver.

The present invention has been made to address the above-mentioned problems. That is, one of the objectives of the present invention is to provide a driving assistance device that allows a vehicle to travel on a curved road at an appropriate vehicle speed so as not to cause the driver anxiety about deviation.

The driving assistance device of the present invention (hereinafter referred to as the "device of the present invention") comprises:
An acquisition unit (22, 23, 27, 30, step 310, step 325) that acquires a degree of curvature of a lane on which a vehicle is traveling;
a control unit (20, steps 945, 950, and 955) that performs acceleration/deceleration control to cause the vehicle to travel on the curved road by acquiring a smaller target vehicle speed as the degree of curvature increases (step 915) and controlling the acceleration/deceleration so that the target acceleration/deceleration acquired so that the vehicle speed approaches the target vehicle speed and the acceleration/deceleration of the vehicle coincide with each other, when it is determined that the vehicle is entering a curved road based on the degree of curvature (step 615 "Yes");
Equipped with
The acquisition unit is configured to acquire, in addition to the degree of curvature, a road shoulder width, which is a distance between a dividing line that divides the lane and a road edge, and a height of a roadside object provided along the lane (steps 330 and 340);
The control unit is
The smaller the shoulder width, the smaller the target vehicle speed is obtained (step 920, step 940).
The lower the height of the roadside object, the smaller the target vehicle speed is acquired (step 925, step 940).
It is structured as follows.

The narrower the shoulder width and the lower the height of the roadside object, the greater the driver's anxiety about deviation, and the driver tends to want the vehicle to travel at a slower speed on the curved road. With the device of the present invention, the narrower the shoulder width, the smaller the target speed is acquired, and the lower the height of the roadside object, the smaller the target vehicle speed is acquired, so that the vehicle can travel on the curved road at an appropriate vehicle speed according to the shoulder width and the height of the roadside object. This reduces the possibility that the driver will feel anxious due to the shoulder width and the height of the roadside object when traveling on a curved road.

In one embodiment of the device of the present invention,
The acquisition unit is further configured to acquire a width of the lane (step 335);
The control unit is further configured to acquire a smaller target vehicle speed as the width of the lane becomes smaller (steps 930 and 940).

The narrower the lane width, the more likely the driver feels that the vehicle will deviate from the lane, and so the driver tends to want the vehicle to travel at a slower speed on a curved road. According to this aspect, the narrower the lane width, the smaller the target vehicle speed obtained, so that the vehicle can travel on a curved road at an appropriate vehicle speed according to the lane width. This reduces the possibility that the driver will feel uneasy due to the lane width when the vehicle is traveling on a curved road.

In one embodiment of the device of the present invention,
The acquisition unit is further configured to acquire an altitude of the current position of the vehicle (step 345, step 350);
The control unit is further configured to acquire a smaller target vehicle speed as the altitude increases (steps 935 and 940).

On curved roads at high altitudes, the driver feels a greater sense of fear that the vehicle VA may deviate from the lane and fall off, so the driver tends to want the vehicle to travel on the curved road at a slow speed. According to this aspect, the higher the altitude, the lower the target vehicle speed obtained, so that the vehicle can travel on the curved road at an appropriate vehicle speed according to the altitude. This reduces the possibility that the driver will feel anxious due to the altitude when traveling on a curved road.

In one embodiment of the device of the present invention,
The acquisition unit is
The sum of a left shoulder width (WaL) which is the distance between a left lane marking (WLL) on the left side and a left road edge (REL) which define the lane, and a right shoulder width (WaR) which is the distance between a right lane marking (WLR) on the right side and a right road edge (RER) which define the lane, is obtained as the shoulder width (step 330);
It is structured as follows.

According to this aspect, the target vehicle speed can be obtained based on the total value of both the inside and outside shoulder widths of the curved road, making it possible to obtain a more appropriate target vehicle speed than if the target vehicle speed were obtained based on only one side of the shoulder width.

In the above description, in order to aid in understanding the 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 embodiment. However, each component of the invention is not limited to the embodiment 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.

FIG. 1 is a schematic system configuration diagram of a driving assistance device according to an embodiment of the present invention. FIG. 2A is an explanatory diagram of the shoulder width of one lane and roadside objects. FIG. 2B is an explanatory diagram of the shoulder width and roadside objects of a two-lane road. FIG. 3 is a flowchart showing a routine for obtaining various values executed by the CPU of the driving assistance ECU shown in FIG. FIG. 4 is a flowchart showing a routine for determining whether or not the ACC start condition is satisfied, which is executed by the CPU of the driving assistance ECU shown in FIG. FIG. 5 is a flowchart showing a routine for determining whether or not the ACC end condition is satisfied, which is executed by the CPU of the driving support ECU shown in FIG. FIG. 6 is a flowchart showing a routine for determining whether or not the SPM start condition is satisfied, which is executed by the CPU of the driving support ECU shown in FIG. FIG. 7 is a flowchart showing a routine for determining whether or not the SPM termination condition is satisfied, which is executed by the CPU of the driving support ECU shown in FIG. FIG. 8 is a flowchart showing a target acceleration/deceleration transmission routine executed by the CPU of the driving support ECU shown in FIG. FIG. 9 is a flowchart showing a second required acceleration/deceleration obtaining routine executed by the CPU of the driving support ECU shown in FIG. FIG. 10 is an explanatory diagram of a section that forms a curved road. FIG. 11 is an explanatory diagram of changes in the curvature of a curved road and changes in lateral acceleration and lateral jerk when a vehicle travels on a curved road. FIG. 12 is an explanatory diagram of the first gain map. FIG. 13 is an explanatory diagram of the second gain map. FIG. 14 is an explanatory diagram of the third gain map. FIG. 15 is an explanatory diagram of the fourth gain map.

Hereinafter, a driving assistance device (hereinafter, referred to as "this assistance device") 10 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows this assistance device 10 and a vehicle VA on which this assistance device 10 is mounted (applied).

As shown in FIG. 1, the assistance device 10 includes a driving assistance ECU (hereinafter referred to as "DSECU") 20, an engine ECU 40, and a brake ECU 50. These ECUs are connected to each other via a controller area network (CAN) so that they can exchange data (communicate).

ECU is an abbreviation for Electronic Control Unit, and is an electronic control circuit whose main components are a microcomputer including a CPU, ROM, RAM, and an interface. The CPU performs various functions by executing instructions (routines) stored in the memory (ROM). All or some of the above ECUs 20, 40, and 50 may be integrated into a single ECU.

Furthermore, the assistance device 10 includes a plurality of wheel speed sensors 21, a yaw rate sensor 22, a camera device 23, a millimeter wave radar device 24, an acceleration sensor 25, an ACC (Adaptive Cruise Control) switch 26, and a locator system 27. These are connected to the DSECU 20.

A wheel speed sensor 21 is provided for each wheel of the vehicle VA. Each wheel speed sensor 21 generates one wheel pulse signal each time the corresponding wheel rotates a predetermined angle. The DSECU 20 counts the number of pulses per unit time of the wheel pulse signal received from each wheel speed sensor 21, and obtains the rotational speed (wheel speed) of each wheel based on the number of pulses. The DSECU 20 obtains a vehicle speed Vs indicating the speed of the vehicle VA based on the wheel speed of each wheel. As an example, the DSECU 20 obtains the average value of the wheel speeds of the four wheels as the vehicle speed Vs.

The yaw rate sensor 22 detects the magnitude of the yaw rate acting on the vehicle VA and outputs a signal that represents the magnitude of the detected yaw rate as yaw rate Yr.

The camera device 23 is disposed above the front window inside the vehicle cabin. The camera device 23 acquires an image (camera image) of the area in front of the vehicle VA, and acquires from the image object information (such as the distance to the object and the direction of the object) and "information relating to the white lines (demarcation lines) that divide the lane in which the vehicle is traveling (hereinafter referred to as "white line information")."

The millimeter wave radar device 24 is installed near the center of the front end of the vehicle VA in the vehicle width direction. The millimeter wave radar device 24 emits millimeter waves that propagate within a predetermined range in front of the vehicle VA. The millimeter waves are reflected by objects (e.g., other vehicles and roadside objects (guardrails, fences, curbs, etc.)). The millimeter wave radar device 24 receives the reflected waves and obtains object information based on the reflected waves. The object information includes the distance to the object, the object's relative speed with respect to the vehicle VA, and the object's orientation with respect to the vehicle VA.

The DSECU 20 corrects the object information acquired by the millimeter wave radar device 24 based on the object information acquired by the camera device 23 to acquire the final object information to be used for the ACC (cruise control) described below.

The acceleration sensor 25 detects the acceleration/deceleration in the longitudinal direction (forward/backward direction) of the vehicle VA (hereinafter referred to as "acceleration/deceleration Gx") and the acceleration in the lateral direction (vehicle width direction) of the vehicle VA (hereinafter referred to as "lateral acceleration Gy"), and transmits detection signals representing these accelerations to the DSECU 20.

The ACC switch 26 is a switch that the driver operates when switching the ACC execution state between an execution permitted state and an execution prohibited state. The execution permitted state means a state in which ACC is executed, and the execution prohibited state means a state in which ACC is not executed. When the driver operates the ACC switch 26 when the ACC execution state is in the execution prohibited state, the DSECU 20 sets the execution state to the execution permitted state. On the other hand, when the driver operates the ACC switch 26 when the ACC execution state is in the execution permitted state, the DSECU 20 sets the execution state to the execution prohibited state.

Furthermore, the ACC switch 26 is also the switch that the driver operates when setting the settings used in ACC (such as the set target vehicle speed Vset and the target following distance Dtgt, which will be described later).

The locator system 27 has a GNSS (Global Navigation Satellite System) receiver 28. The GNSS receiver 28 receives GNSS signals from multiple SNSS satellites, identifies the current position (position on the Earth's surface) of the vehicle VA based on the multiple received GNSS signals, and transmits a position signal indicating the current position to the DSECU 20. Furthermore, the locator system 27 pre-stores map data 29. The map data 29 includes the "altitude Hb of each position on the Earth's surface" and the like.

The engine ECU 40 is connected to an accelerator pedal operation amount sensor 42 and an engine sensor 44, and receives detection signals from these sensors.

The accelerator pedal operation amount sensor 42 detects the amount of operation of the accelerator pedal (not shown) of the vehicle VA (i.e., the accelerator pedal operation amount AP). When the driver is not operating the accelerator pedal, the accelerator pedal operation amount AP is "0".

The engine sensor 44 is a sensor that detects the operating state quantities of the "gasoline fuel injection, spark ignition, internal combustion engine that is the driving source of the vehicle VA" (not shown). The engine sensor 44 includes a throttle valve opening sensor, an engine speed sensor, and an intake air volume sensor.

Furthermore, the engine ECU 40 is connected to engine actuators 46, such as a "throttle valve actuator and a fuel injection valve." The engine ECU 40 changes the torque generated by the internal combustion engine by driving the engine actuators 46, thereby adjusting the driving force of the vehicle VA.

The engine ECU 40 determines the target throttle valve opening TAtgt so that the target throttle valve opening TAtgt increases as the accelerator pedal operation amount AP increases. The engine ECU 40 drives the throttle valve actuator so that the throttle valve opening coincides with the target throttle valve opening TAtgt.

The brake ECU 50 is connected to the wheel speed sensor 21 and the brake pedal operation amount sensor 52 and receives the detection signals from these sensors.

The brake pedal operation amount sensor 52 detects the amount of operation of the brake pedal (not shown) of the vehicle VA (i.e., the brake pedal operation amount BP). When the brake pedal is not operated, the brake pedal operation amount BP is "0".

The brake ECU 50 obtains the rotational speed of each wheel and the vehicle speed Vs in the same manner as the DSECU 20 based on the wheel pulse signal from the wheel speed sensor 21. Note that the brake ECU 50 may obtain these from the DSECU 20.

The brake ECU 50 is further connected to a brake actuator 54. The brake actuator 54 is a hydraulically controlled actuator. The brake actuator 54 is disposed in a hydraulic circuit (both not shown) between a master cylinder that pressurizes hydraulic oil by the force applied to the brake pedal, and a friction brake device including a well-known wheel cylinder provided on each wheel. The brake actuator 54 adjusts the hydraulic pressure supplied to the wheel cylinder, thereby adjusting the braking force of the vehicle VA.

The brake ECU 50 determines a "negative target acceleration/deceleration" based on the brake pedal operation amount BP. The brake ECU 50 drives the brake actuator 54 so that the actual acceleration/deceleration Gx of the vehicle VA matches the target acceleration/deceleration.

The assistance device 10 further includes a display device 60. For example, the display device 60 is a HUD (head-up display) on the front window. The display device 60 displays the execution status of ACC, the set target vehicle speed Vset, the presence or absence of a "vehicle (preceding vehicle) traveling in front of the vehicle VA," and the presence or absence of deceleration due to SPM control.

<ACC>
The DSECU 20 judges whether or not a preceding vehicle is present in front of the vehicle VA based on the object information acquired by the millimeter wave radar device 24 and the object information acquired by the camera device 23. The preceding vehicle is a vehicle that is present within a predetermined distance from the front end of the vehicle VA toward the front of the vehicle VA. The DSECU 20 executes ACC when the execution state of ACC is in an execution permission state. When there is no preceding vehicle, the DSECU 20 calculates Gxcc for driving the vehicle VA at a constant speed at the set target vehicle speed Vset, and executes constant speed control based on this required acceleration/deceleration Gxacc. On the other hand, when there is a preceding vehicle, the DSECU 20 calculates a required acceleration/deceleration Gxacc for driving the vehicle VA so that the inter-vehicle distance between the preceding vehicle and the vehicle VA becomes the target inter-vehicle distance Dtgt, and executes tracking control based on this required acceleration/deceleration Gxacc. Hereinafter, the required acceleration/deceleration Gxcc and Gxacc will be referred to as a "first required acceleration/deceleration Gx1."

<SPM Control>
When the vehicle VA enters a curved road while ACC is being executed and a predetermined SPM start condition described later is satisfied, the DSECU 20 executes speed management control (hereinafter referred to as "SPM control" or sometimes referred to as "acceleration/deceleration control"). The SPM control is a control for changing the acceleration/deceleration Gx of the vehicle VA so that the vehicle VA travels on the curved road at an appropriate vehicle speed Vs.

When the DSECU 20 is executing the SPM control, the DSECU 20 acquires the target vehicle speed Vtgt based on the "curvature C indicating the degree of curvature of the curved road" and acquires the "requested acceleration/deceleration Gxspm acquired so that the vehicle speed Vs approaches the target vehicle speed Vstgt" as the second requested acceleration/deceleration Gx2. Note that the larger the curvature C, the larger (sharper) the degree of curvature of the curved road. The DSECU 20 uses the smaller of the first requested acceleration/deceleration Gx1 and the second requested acceleration/deceleration Gx2 as the target acceleration/deceleration Gxtgt and transmits it to the engine ECU 40 and the brake ECU 50.
When the engine ECU 40 receives the target acceleration/deceleration Gxtgt, it controls the throttle valve actuator using the larger of "the throttle valve opening for making the current acceleration/deceleration Gx match the target acceleration/deceleration Gxtgt" and "the throttle valve opening corresponding to the accelerator pedal operation amount AP" as the target throttle valve opening Tatgt.
When the brake ECU 50 receives the target acceleration/deceleration Gxtgt, it controls the brake actuator 54 using the smaller of the received target acceleration/deceleration Gxtgt and the "target acceleration/deceleration according to the brake pedal operation amount BP" as a target braking force.
When the DSECU 20 is not executing SPM control, the DSECU 20 transmits the first required acceleration/deceleration Gx1 as the target acceleration/deceleration Gxtgt to the engine ECU 40 and the brake CU 50.

(Overview of operation)
In this embodiment, the DSECU 20 obtains the target vehicle speed Vtgt based on the curvature C of the curved road, the width Wa of the shoulder of the lane SL (hereinafter referred to as the "shoulder width"), and the height Ha of a roadside object RO from the ground, which will be described later. The lane SL is the lane on which the vehicle VA is currently traveling.

<Curvature C>
The larger the curvature C, the smaller the acquired target vehicle speed Vtgt. The DSECU 20 estimates the curvature C (hereinafter referred to as the "estimated curvature Cp") of the preview point PP (see Figs. 2A and 2B) based on the white line information acquired from the camera device 23 as the above curvature C. The preview point PP is a point a predetermined distance L away from the front end of the vehicle VA along a virtual line VL passing through the center in the width direction of the lane SL.

<Shoulder width Wa>
The DSECU 20 recognizes the white line WL ahead of the vehicle VA based on the white line information acquired from the camera device 23. As shown in Fig. 2A, the DSECU 20 recognizes an area defined by a white line WLL on the left side of the vehicle VA and a white line WLR on the right side of the vehicle VA as a lane SL. The DSECU 20 then acquires the "width (length) between the left road edge REL in the perpendicular direction to the virtual line VL at the preview point PP and the white line WLL" as the road shoulder width WaL, and acquires the "width (length) between the right road edge RER in the perpendicular direction and the white line WLR" as the road shoulder width WaR. The DSECU 20 acquires the sum of the road shoulder width WaL and the road shoulder width WaR as the road shoulder width Wa.

The DSECU 20 judges whether or not a roadside object RO such as a curb, a guard rail, or a fence is present outside the white line that defines the lane SL, based on the object information from the camera device 23 and the millimeter wave radar device 24. More specifically, the roadside object RO is "an object that is present within a predetermined distance to the left of the white line WLL (or to the right of the white line WLR) and has a length equal to or greater than a predetermined length along the lane SL."
When a roadside object RO exists, the DSECU 20 specifies a point of the roadside object RO intersecting with the perpendicular line as the road edge. In Fig. 2A, a roadside object (guardrail) RO exists on the left side of the white line WLL, so the DSECU 20 specifies a point of the roadside object RO intersecting with the perpendicular line as the road edge REL. The DSECU 20 acquires the distance between the road edge REL and "a point PL of the white line WLL intersecting with the perpendicular line" as the road shoulder width WaL. On the other hand, since there is no roadside object RO on the right side of the white line WLR, the DSECU 20 extracts an edge line from the image information from the camera device 23, and specifies a point of the edge line "existing within a range of a predetermined distance to the right of the white line WLL and extending along the white line WLR" intersecting with the perpendicular line as the road edge RER. The DSECU 20 acquires the distance between the road edge RER and the point PR at which the white line WLR intersects with the perpendicular line as the road shoulder width WaR.

The above-mentioned predetermined distance is preset to a value smaller than the minimum lane width in general (e.g., 2.75 m).

Figure 2B shows a road with two lanes. In Figure 2B, the DSECU 20 detects the edge line of the white line WL further to the right of the white line WLR that divides the lane SL, but the distance between this edge line and the white line WLR is longer than the above-mentioned specified distance. Therefore, in Figure 2B, neither the roadside object RO nor the edge line is present within the above-mentioned specified distance to the right of the white line WLR. In this case, the DSECU 20 identifies the point PR where the white line WLR intersects with the above-mentioned perpendicular direction as the road edge RER. Since the distance between the road edge PER and point PR is zero, the road shoulder width WaR is zero.

On a curved road with a narrow shoulder width Wa, the vehicle VA is more likely to cross the shoulder if it deviates from the lane SL than on a curved road with a wide shoulder width Wa, so the driver feels greater "anxiety that the vehicle VA may deviate from the lane SL." For this reason, drivers tend to want the vehicle VA to travel at a slower speed on a curved road with a narrow shoulder width Wa than on a curved road with a wide shoulder width Wa. Therefore, the DSECU 20 acquires a smaller target vehicle speed Vstgt the narrower the shoulder width Wa.

For the sake of simplicity, Figures 2A and 2B show an example in which the lane SL is a straight road, but even if the lane SL is a curved road, the shoulder width Wa can be obtained by using the above method.

<Roadside object height Ha>
On a curved road where the height Ha of the roadside object RO is low, the possibility of the vehicle VA running over the roadside object RO is high when the vehicle VA deviates from the roadside object RO compared to a curved road where the height Ha of the roadside object RO is high, and the anxiety of the vehicle VA deviating from the roadside object RO is high. For this reason, the driver tends to want to drive the vehicle VA at a slower speed on a curved road where the height Ha of the roadside object RO is low than on a curved road where the height Ha of the roadside object RO is high. Therefore, the DSECU 20 acquires a smaller target vehicle speed Vstgt as the height Ha of the roadside object RO decreases. The DSECU 20 acquires the height Ha of the roadside object RO based on image information acquired from the camera device 23.

Although not shown in Figures 2A and 2B, there may be a roadside object ROL to the left of the white line WLL, and a roadside object ROR to the right of the white line WLR. In this case, the DSECU 20 acquires the sum of the height Ha of the roadside object ROL and the height Ha of the roadside object ROR as the height Ha of the roadside object RO.

As a result, the vehicle VA can travel on the curved road at an appropriate vehicle speed Vs according to the shoulder width Wa and the height Ha of the roadside object RO, reducing the possibility that the driver will feel anxious about deviation due to the shoulder width Wa and the height Ha of the roadside object RO.

(Specific operation)
<Various value acquisition routine>
The CPU of the DSECU 20 (hereinafter, when the term "CPU" is used, it refers to the CPU of the DSECU 20 unless otherwise specified) executes a various value acquisition routine shown in the flowchart of FIG. 3 every time a predetermined time has elapsed.

Therefore, at a predetermined timing, the CPU starts processing from step 300 in FIG. 3 and executes steps 305 to 350 in this order. After that, the CPU proceeds to step 395 and temporarily ends this routine.

Step 305 : The CPU obtains the yaw rate Yr based on the signal from the yaw rate sensor 22 , and obtains the vehicle speed Vs based on the wheel pulse signal from the wheel speed sensor 21 .
Step 310: The CPU calculates the actual curvature Ca, which is the curvature C at the current position of the vehicle VA, the lateral acceleration Gy, and the "lateral jerk Jy, which is the time differential value of the lateral acceleration Gy."
More specifically, the CPU obtains the actual curvature Ca by applying the yaw rate Yr and the vehicle speed Vs to Equation 1.
Ca=Yr/Vs...Formula 1
Furthermore, the CPU obtains the lateral acceleration Gy by applying the yaw rate Yr and the vehicle speed Vs to Equation 2.
Gy = Yr x Vs ... Equation 2
Furthermore, the CPU obtains the lateral jerk Jy by applying the currently calculated lateral acceleration Gy(n) and the previously calculated lateral acceleration Gy(n-1) (a predetermined time ago, that is, one calculation cycle ago) to equation 3.
Jy=Gy(n)-Gy(n-1)...Formula 3

Step 315: The CPU acquires image information, target information, and white line information from the camera device 23.
Step 320: The CPU recognizes (identifies) the white lines based on the white line information.
Step 325: The CPU obtains the curvature C of the preview point PP as an estimated curvature Cp.

Step 330: The CPU obtains the road shoulder width Wa based on the image information, the white line information and the object information.
Step 335: The CPU obtains the lane width Wb (see FIGS. 2A and 2B) of the lane SL. The lane width Wb is the distance between the white line WL1 and the white line WL2.
Step 340: The CPU obtains the height Ha of the roadside object RO based on the image information.
Step 345: The CPU determines the current position of the vehicle VA based on the position signal from the GNSS receiver 28.
Step 350: The CPU obtains the altitude Hb at the current position of the vehicle VA from the map data 29.

<ACC start condition satisfaction determination routine>
The CPU executes a routine for determining whether or not the ACC initiation condition is satisfied, which is shown in the flow chart of FIG. 4, every time a predetermined time elapses.

Therefore, at a predetermined timing, the CPU starts processing from step 400 in FIG. 4 and proceeds to step 405. In step 405, the CPU determines whether the value of the ACC flag Xacc is "0". The value of the ACC flag Xacc is set to "1" if ACC is being executed, and is set to "0" if ACC is not being executed. The value of the ACC flag Xacc is set to "0" in an initial routine executed by the CPU when an ignition key switch (not shown) of the vehicle VA is changed from the OFF position to the ON position.

If the value of the ACC flag Xacc is "0", the CPU judges "Yes" in step 405 and proceeds to step 410. In step 410, the CPU judges whether the ACC switch 26 has been operated.

If the ACC switch 26 has not been operated, the CPU judges "No" in step 410, proceeds to step 495, and temporarily ends this routine. In contrast, if the ACC switch 26 has been operated, the CPU judges "Yes" in step 410, and executes steps 415 and 420 in that order. Thereafter, the CPU proceeds to step 495, and temporarily ends this routine.

Step 415: The CPU sets the value of the ACC flag Xacc to “1”.
Step 420: The CPU sets the value of the SPM flag Xspm to “0”.

The value of the SPM flag Xspm is set to "1" when SPM control is being executed, and is set to "0" when SPM control is not being executed. The value of the SPM flag Xspm is set to "0" in the above initial routine.

If the value of the ACC flag Xacc is "1" when the CPU proceeds to step 405, the CPU determines "No" in step 405, proceeds to step 495, and temporarily ends this routine.

<ACC End Condition Satisfaction Determination Routine>
The CPU executes a routine for determining whether or not the ACC end condition is satisfied, which is shown in the flowchart of FIG. 5, every time a predetermined time has elapsed.

Therefore, at a predetermined timing, the CPU starts processing from step 500 in FIG. 5 and proceeds to step 505. In step 505, the CPU determines whether the value of the ACC flag Xacc is "1".

If the value of the ACC flag Xacc is "1", the CPU judges "Yes" in step 505 and proceeds to step 510. In step 510, the CPU judges whether the ACC switch 26 has been operated.

If the ACC switch 26 has not been operated, the CPU judges "No" in step 510, proceeds to step 595, and temporarily ends this routine. In contrast, if the ACC switch 26 has been operated, the CPU judges "Yes" in step 510, and executes steps 515 and 520 in that order. Thereafter, the CPU proceeds to step 595, and temporarily ends this routine.

Step 515: The CPU sets the value of the ACC flag Xacc to “0”.
Step 520: The CPU sets the value of the SPM flag Xspm to “0”.

On the other hand, if the value of the ACC flag Xacc is "0" when the CPU proceeds to step 505, the CPU judges "No" at step 505, proceeds to step 595, and temporarily ends this routine.

<SPM start condition satisfaction determination routine>
The CPU executes a routine for determining whether or not an SPM start condition is satisfied, which is shown in the flow chart of FIG. 6, every time a predetermined time has elapsed.

Therefore, at a predetermined timing, the CPU starts processing from step 600 in FIG. 6 and proceeds to step 605. In step 605, the CPU determines whether the value of the ACC flag Xacc is "1".

If the value of the ACC flag Xacc is "0", the CPU judges "No" in step 605, proceeds to step 695, and temporarily ends this routine. In contrast, if the value of the ACC flag Xacc is "1", the CPU judges "Yes" in step 605, and proceeds to step 610.

In step 610, the CPU determines whether the value of the SPM flag Xspm is "0". If the value of the SPM flag Xspm is "0", the CPU determines "Yes" in step 610 and proceeds to step 615. In step 615, the CPU determines whether the estimated curvature Cp is equal to or greater than the threshold curvature Cpth.

If the estimated curvature Cp is less than the threshold curvature Cpth, the CPU determines "No" in step 615, proceeds to step 695, and ends this routine. In contrast, if the estimated curvature Cp is equal to or greater than the threshold curvature Cpth, the CPU determines that a predetermined SPM start condition that is satisfied when the vehicle VA enters a curved road is satisfied. In this case, the CPU determines "Yes" in step 615, and proceeds to step 620. In step 620, the CPU sets the value of the SPM flag Xspm to "1", proceeds to step 695, and ends this routine.

On the other hand, if the value of the SPM flag Xspm is "1" when the CPU proceeds to step 610, the CPU judges "No" at step 610, proceeds to step 695, and temporarily ends this routine.

<SPM End Condition Establishment Determination Routine>
The CPU executes a routine for determining whether an SPM start condition is satisfied, which is shown in the flowchart of FIG. 7, every time a predetermined time has elapsed.

Therefore, at a predetermined timing, processing starts from step 700 in FIG. 7 and proceeds to step 705. In step 705, the CPU determines whether the value of the ACC flag Xacc is "1".

If the value of the ACC flag Xacc is "0", the CPU judges "No" in step 705, proceeds to step 795, and temporarily ends this routine. On the other hand, if the value of the ACC flag Xacc is "1", the CPU judges "Yes" in step 705, and proceeds to step 710.

In step 710, the CPU determines whether the value of the SPM flag Xspm is "1". If the value of the SPM flag Xspm is "1", the CPU determines "Yes" in step 710 and proceeds to step 715. In step 715, the CPU determines whether the actual curvature Ca is equal to or less than the threshold curvature Cath. If the actual curvature Ca is greater than the threshold curvature Cath, the CPU determines "No" in step 715, proceeds to step 795, and ends this routine. In contrast, if the actual curvature Ca is equal to or less than the threshold curvature Cath, the CPU determines that a predetermined SPM end condition that is established when the vehicle VA exits a curved road is established. In this case, the CPU determines "Yes" in step 715 and proceeds to step 720. In step 720, the CPU sets the value of the SPM flag Xspm to "0", proceeds to step 795, and ends this routine.

On the other hand, if the value of the SPM flag Xspm is "0" when the CPU proceeds to step 710, the CPU determines "No" in step 710, proceeds to step 795, and temporarily ends this routine.

<Target acceleration/deceleration transmission routine>
The CPU executes a target acceleration/deceleration transmission routine shown in the flow chart of FIG. 8 every time a predetermined time elapses.

Therefore, at a predetermined timing, processing starts from step 800 in FIG. 8 and proceeds to step 805. In step 805, the CPU determines whether the value of the ACC flag Xacc is "1".

If the value of the ACC flag Xacc is "0", the CPU judges "No" in step 805, proceeds to step 895, and temporarily ends this routine. On the other hand, if the value of the ACC flag Xacc is "1", the CPU judges "Yes" in step 805, and proceeds to step 810.

In step 810, the CPU determines whether or not a preceding vehicle is present based on the object information acquired from the camera device 23 and the object information acquired from the millimeter wave radar device 24. If a preceding vehicle is not present, the CPU determines "No" in step 810 and executes steps 815 and 820 in sequence.

Step 815: The CPU obtains the required acceleration/deceleration Gxcc.
Step 820: The CPU sets the required acceleration/deceleration Gxcc to a first required acceleration/deceleration Gx1.
Thereafter, the CPU proceeds to step 825 to determine whether the value of the SPM flag Xspm is "1".

If the value of the SPM flag Xspm is "0", the CPU determines "No" in step 825 and proceeds to step 830. In step 830, the CPU transmits the first required acceleration/deceleration Gx1 as the target acceleration/deceleration Gxtgt to the engine ECU 40 and the brake ECU 50, and proceeds to step 895 to temporarily end this routine.

On the other hand, if a preceding vehicle is present when the CPU proceeds to step 810, the CPU determines "Yes" in step 810 and executes steps 835 and 840 in sequence.

Step 835: The CPU obtains the required acceleration/deceleration Gxacc.
Step 840: The CPU sets the required acceleration/deceleration Gxacc to a first required acceleration/deceleration Gx1.
Thereafter, if the value of the SPM flag Xspm is “0”, the CPU makes a “No” determination in step 825 and proceeds to step 830 .

On the other hand, if the value of the SPM flag Xspm is "1" when the CPU proceeds to step 825, the CPU determines "Yes" in step 825 and executes steps 845 and 850 in sequence.

Step 845: The CPU executes a second required acceleration/deceleration acquisition subroutine to acquire the second required acceleration/deceleration Gx2 (i.e., the required acceleration/deceleration Gxspm). In practice, when the CPU proceeds to step 845, it executes the subroutine shown in the flowchart of FIG. 9. The processing in this subroutine will be described later.

Step 850: The CPU determines whether the second required acceleration/deceleration Gx2 is smaller than the first required acceleration/deceleration Gx1.

If the second required acceleration/deceleration Gx2 is smaller than the first required acceleration/deceleration Gx1, the CPU determines "Yes" in step 850 and proceeds to step 855. In step 855, the CPU transmits the second required acceleration/deceleration Gx2 as the target acceleration/deceleration Gxtgt to the engine ECU 40 and the brake ECU 50. After that, the CPU proceeds to step 895 and temporarily ends this routine.

In contrast, if the second required acceleration/deceleration Gx2 is equal to or greater than the first required acceleration/deceleration Gx1, the CPU determines "No" in step 850, proceeds to step 830, and transmits the first required acceleration/deceleration Gx1 as the target acceleration/deceleration Gxtgt.

<Second required acceleration/deceleration acquisition subroutine>
8, the CPU starts the process from step 900 shown in Fig. 9, and proceeds to step 905. In step 905, the CPU determines whether the product (Gy x Jy) of the lateral acceleration Gy and the lateral jerk Jy is equal to or greater than 0.

Here, this determination process will be described with reference to FIG. 10 and FIG.
Generally, the curved road RCU is composed of a first clothoid section RCL1, a steady circle section RSC, and a second clothoid section RCL2, as shown in Fig. 10. In the SPM control, when the vehicle VA travels through the first clothoid section RCL1, a required acceleration/deceleration Gxspm (<0) for decelerating the vehicle VA is acquired. When the vehicle VA travels through the steady circle section RSC, a required acceleration/deceleration Gxspm (=0) for traveling the vehicle VA at a constant speed is acquired. When the vehicle VA travels through the second clothoid section RCL2, a required acceleration/deceleration Gxspm (>0) for accelerating the vehicle VA is acquired. The determination in step 905 is performed to determine which section of the curved road RCU the vehicle VA is traveling through.

As shown in FIG. 11, the curvature C of the curved road RCU gradually increases in the first clothoid section RCL1, becomes a constant value in the steady circle section RSC, and gradually decreases in the second clothoid section RCL.
The lateral acceleration Gy and the lateral jerk Jy when the vehicle VA travels along a curved road RCU while the driver steers the steering wheel (not shown) of the vehicle VA in accordance with the curvature C of the curved road RCU are as shown in FIG.
That is, in the first clothoid section RCL1, the lateral acceleration Gy gradually increases from zero, and the lateral jerk Jy rises instantaneously at the timing when the lateral acceleration Gy starts to increase and is maintained at a constant value (>0). Therefore, the above product (Gy×Jy) is a positive value.
In the steady circle section RSC, the lateral acceleration Gy is maintained at a constant value (>0), and the lateral jerk Jy is maintained at zero. Therefore, the above product (Gy×Jy) is zero.
In the second clothoid section RCL2, the lateral acceleration Gy gradually decreases, and the lateral jerk Jy instantaneously changes to a constant negative value at the timing when the lateral acceleration Gy starts to decrease and is maintained at that value. Therefore, the above product (Gy×Jy) becomes a negative value.

In step 905, the CPU determines which section of the curved road RCU the vehicle VA is traveling through based on the product (Gy x Jy).

Returning to FIG. 9, the description of the second required acceleration/deceleration obtaining subroutine will be continued.
If the product (Gy·Jy) is equal to or greater than zero, that is, if the vehicle VA is located in the first clothoid section RCL1 or the steady circle section RSC, the CPU determines "Yes" in step 905 and executes steps 910 to 955 in this order. After that, the CPU proceeds to step 995 and temporarily ends this routine.

Step 910: The CPU obtains the base acceleration/deceleration Gxb by multiplying the absolute value of the lateral jerk Jy by "-1". In principle, the base acceleration/deceleration Gxb is a negative value, which is a deceleration. However, when the vehicle VA is located in the steady circle section RSC, as described above, the value of the lateral jerk Jy is zero, and therefore the base acceleration/deceleration Gxb is zero. In this case, the required acceleration/deceleration Gxspm, which will be described later, is also zero.

Step 915: The CPU obtains the curvature-corresponding vehicle speed Vsc by applying the actual curvature Ca to the curvature-corresponding vehicle speed map MapVsc(C) shown in block B91 of FIG. 9. The curvature-corresponding vehicle speed map MapVsc(C) is a lookup table that correlates the curvature C with the target vehicle speed Vtgt such that the larger the curvature C, the smaller (lower) the curvature-corresponding vehicle speed Vsc becomes. The curvature-corresponding vehicle speed map MapVsc(C) is pre-stored in the ROM of the DSECU 20.

Step 920: The CPU obtains the first gain Ga1 by applying the shoulder width Wa to the first gain map MapGa1(Wa) shown in FIG.
The first gain map MapGa1 (Wa) is a look-up table that associates the road shoulder width Wa with the first gain Ga1, and is stored in advance in the ROM of the DSECU 20.
According to the first gain map MapGa1(Wa), when the shoulder width Wa is any value between "0" and the first predetermined value Wa1 (>0), the first gain Ga1 is "0.3". Furthermore, when the shoulder width Wa is any value between the first predetermined value Wa1 and the second predetermined value Wa2 (>Wa1), the first gain Ga1 increases from "0.3" toward "1.0" as the shoulder width Wa increases. Furthermore, when the shoulder width Wa is equal to or larger than the second predetermined value Wa2, the first gain Ga1 is "1.0".

Step 925: The CPU obtains the second gain Ga2 by applying the height Ha of the roadside object RO to the second gain map MapGa2(Ha) shown in FIG.
The second gain map MapGa2(Ha) is a look-up table that associates the height Ha with the second gain Ga2, and is stored in advance in the ROM of the DSECU 20.
According to the second gain map MapGa2(Ha), when the height Ha is any value between "0" and the first predetermined value Ha1 (>0), the second gain Ga2 is "0.5". Furthermore, when the height Ha is any value between the first predetermined value Ha1 and the second predetermined value Ha2 (>Ha1), the second gain Ga2 increases from "0.5" toward "1.0" as the height Ha increases. Furthermore, when the height Ha is equal to or greater than the second predetermined value Ha2, the second gain Ga2 is "1.0".

Step 930: The CPU obtains the third gain Ga3 by applying the lane width Wb to the third gain map MapGa3(Wb) shown in FIG.
The third gain map MapGa3(Wb) is a look-up table that associates the lane width Wb with the third gain Ga3, and is stored in advance in the ROM of the DSECU 20.
According to the third gain map MapGa3(Wb), when the lane width Wb is any value between "0" and the first predetermined value Wb1 (>0), the third gain Ga3 is "0.5". Furthermore, when the lane width Wb is any value between the first predetermined value Wb1 and the second predetermined value Wb2 (>Wb1), the third gain Ga3 increases from "0.5" toward "1.0" as the lane width Wb increases. Furthermore, when the lane width Wb is equal to or larger than the second predetermined value Wb2, the third gain Ga3 is "1.0".

Step 935: The CPU obtains the fourth gain Ga4 by applying the altitude Hb to the fourth gain map MapGa4(Hb) shown in FIG.
The fourth gain map MapGa4(Hb) is a look-up table that associates the altitude Hb with the fourth gain Ga4, and is stored in advance in the ROM of the DSECU 20.
According to the fourth gain map MapGa4(Hb), when the altitude Hb is any value between "0" and the first predetermined value Hb1 (>0), the fourth gain Ga4 is "1.0". Furthermore, when the altitude Hb is any value between the first predetermined value Hb1 and the second predetermined value Hb2 (>Hb1), the second gain Ga2 decreases from "1.0" toward "0.3" as the altitude Hb increases. Furthermore, when the altitude Hb is equal to or greater than the second predetermined value Hb2, the second gain Ga2 is "0.3".

Step 940: The CPU applies the first gain Ga1, the second gain Ga2, the third gain Ga3, the fourth gain Ga4, and the curvature-adapted vehicle speed Vsc to Equation 4 to obtain the target vehicle speed Vstgt.
Vstgt=(Ga1*Vsc+Ga2*Vsc+Ga3*Vsc+Ga4*Vsc)/4 …Equation 4

Step 945: The CPU obtains a vehicle speed deviation ΔV (Vstgt−Vs) by subtracting the current vehicle speed Vs from the target vehicle speed Vstgt.
Step 950: The CPU obtains the gain Ga by applying the vehicle speed deviation ΔV to the gain map MapGa(ΔV) shown in block B92 of FIG. 9. The gain map MapGa(ΔV) is a lookup table that associates the vehicle speed deviation ΔV with the gain Ga, and is prestored in the ROM of the DSECU 20. According to the gain map MapGa(ΔV), when the vehicle speed deviation ΔV is a negative value (i.e., Vstgt<Vs), the value of the gain Ga becomes "1". On the other hand, when the vehicle speed deviation ΔV is a positive value (i.e., Vstgt>Vs), the value of the gain Ga decreases from "1" toward "0" as the vehicle speed deviation ΔV increases.

Step 955: The CPU obtains the required acceleration/deceleration Gxspm by multiplying the base acceleration/deceleration Gxb by the gain Ga.

On the other hand, if the product (Gy x Jy) is a negative value when the CPU proceeds to step 905, i.e., if the vehicle VA is located in the second clothoid section RCL2, the CPU determines "No" in step 905 and proceeds to step 960. In step 960, the CPU obtains the absolute value of the lateral jerk Jy as the required acceleration/deceleration Gxspm, proceeds to step 995, and temporarily ends this routine.

According to this embodiment, the smaller (narrower) the road shoulder width Wa is, the closer to "0" the first gain Ga1 is obtained, and the smaller the target vehicle speed Vstgt is. Furthermore, the lower the height Ha of the roadside object RO is, the closer to "0" the second gain Ga2 is obtained, and the smaller the target vehicle speed Vstgt is. This increases the likelihood that the vehicle VA can travel on the curved road RCU at an appropriate vehicle speed Vs that does not make the driver feel anxious about departure, and reduces the likelihood that the driver will feel anxious about departure.

On a curved road with a narrow lane width Wb, the vehicle VA is more likely to deviate from the lane SL than on a curved road with a wide lane width Wb. For this reason, the driver tends to want the vehicle VA to run at a slower speed on a curved road with a narrow lane width Wb than on a curved road with a wide lane width Wb. In addition, on a curved road with a high altitude Hb, the driver feels a greater fear that the vehicle VA will deviate from the lane SL and fall off than on a curved road with a low altitude Hb. For this reason, the driver tends to want the vehicle VA to run at a slower speed on a curved road with a high altitude Hb than on a curved road with a low altitude Hb. According to this embodiment, the smaller (narrower) the lane width Wb is, the closer to "0" the third gain Ga3 is acquired, so the smaller the target vehicle speed Vstgt is. Furthermore, the higher the altitude Hb is, the closer to "0" the fourth gain Ga4 is acquired, so the smaller the target vehicle speed Vstgt is. This further increases the likelihood that the vehicle VA can travel along the curved road RCU at an appropriate vehicle speed Vs that does not cause the driver to feel anxious about deviation, and further reduces the likelihood that the driver will feel anxious about deviation.

The present invention is not limited to the above-described embodiment and modifications, and various modifications can be adopted within the scope of the present invention.

If the map data 29 includes the shoulder width Wa, the height Ha of the roadside object RO, and the lane width Wb at each position on the ground surface, the DSECU 20 may obtain the shoulder width Wa, height Ha, and lane width Wb corresponding to the current position of the vehicle VA from the map data 29.
When the map data 29 includes the position of the curved road on the ground surface and the curvature C of the curved road, the DSECU 20 may use the curvature C of the preview point PP as the estimated curvature Cp and the curvature C of the current position of the vehicle VA as the actual curvature Ca.

The DSECU 20 may obtain subtraction vehicle speeds D1 to D4 (≧0) corresponding to the shoulder width Wa, the height Ha of the roadside object RO, the lane width Wb, and the altitude Hb, respectively, and obtain the target vehicle speed Vstgt by subtracting the subtraction vehicle speeds D1 to D4 from the curvature-adaptive vehicle speed Vsc (see equation 5 below).
Vstgt=Vsc-D1-D2-D3-D4...Formula 5
The subtraction vehicle speed D1 corresponding to the road shoulder width Wa increases as the road shoulder width Wa decreases.
The subtraction vehicle speed D2 corresponding to the height Ha increases as the height Ha decreases.
The subtraction vehicle speed D3 corresponding to the lane width Wb increases as the lane width Wb decreases.
The subtraction vehicle speed D4 corresponding to the altitude Hb increases as the altitude Hb increases.

In step 615 shown in FIG. 6, the DSECU 20 may determine whether the estimated curvature Cp is equal to or greater than the threshold curvature Cpth and the yaw rate Yr is equal to or greater than the threshold curvature Yrth. Furthermore, the actual curvature Ca may be used instead of the estimated curvature Cp. The determination process in step 615 may be a process in which the DSECU 20 determines that the vehicle VA is entering (or has entered) a curved road.

The first gain map MapGa1(Wa) is not limited to the example shown in FIG. 12 as long as the first gain Ga1 is a value between "0" and "1" and the smaller (narrower) the shoulder width Wa is, the closer the first gain Ga1 is to "0."
The second gain map MapGa2(Ha) is not limited to the example shown in FIG. 13 as long as the second gain Ga2 has a value between "0" and "1" and the smaller (lower) the height Ha of the roadside object RO, the closer the second gain Ga2 is to "0".
The third gain map MapGa3(Wb) is not limited to the example shown in FIG. 14, as long as the third gain Ga3 is any value between "0" and "1" and the smaller (narrower) the lane width Wb is, the closer the third gain Ga3 is to "0".
The fourth gain map MapGa4 (Hb) is not limited to the example shown in FIG. 15, as long as the fourth gain Ga4 has a value between "0" and "1" and the height Ha of the roadside object RO is larger (higher), the fourth gain Ga4 approaches "0".

The radius of curvature may be used instead of the curvature C. The smaller the radius of curvature, the greater the curvature of the curved road.

In the above embodiment, a white line is used as an example of the line (demarcation line) that divides the lane SL, but the demarcation line may be of another color.

Furthermore, the support device 10 can also be applied to electric vehicles and hybrid vehicles. Furthermore, the required acceleration/deceleration Gxspm does not need to be obtained by the above-mentioned method if the vehicle speed Vs is a value that approaches the target vehicle speed Vstgt.

10...driving assistance device, 20...driving assistance ECU, 23...camera device, 27...locator system, 40...engine ECU, 50...brake ECU.

Claims (4)

An acquisition unit that acquires a curvature degree of a lane in which a vehicle is traveling;
a control unit that performs acceleration/deceleration control for causing the vehicle to travel on the curved road by acquiring a smaller target vehicle speed as the degree of curvature increases, and controlling the acceleration/deceleration so that the target acceleration/deceleration acquired so that the vehicle speed of the vehicle approaches the target vehicle speed and the acceleration/deceleration of the vehicle coincide with each other when it is determined that the vehicle is entering a curved road based on the degree of curvature;
Equipped with
The acquisition unit is configured to acquire, in addition to the degree of curvature, a road shoulder width, which is a distance between a dividing line that divides the lane and a road edge, and a height of a roadside object provided along the lane,
The control unit is
The smaller the road shoulder width, the smaller the target vehicle speed is acquired;
The lower the height of the roadside object, the smaller the target vehicle speed is acquired.
It is configured as follows :
Furthermore, the control unit
The shoulder width is obtained by adding together a left shoulder width, which is the distance between the left dividing line on the left side of the lane and the left road edge, and a right shoulder width, which is the distance between the right dividing line on the right side of the lane and the right road edge.
It is configured as follows:
Furthermore, the control unit
If the roadside object or an edge line extending along the lane is present within a range of a predetermined distance to the left from the left dividing line, the roadside object or the edge line is identified as the left road edge, and if neither the roadside object nor the edge line is present within a range of the predetermined distance to the left from the left dividing line, the left shoulder width is identified as zero,
When the roadside object or the edge line is present within the range up to the specified distance from the right demarcation line to the right, the roadside object or the edge line is identified as the right road edge, and when neither the roadside object nor the edge line is present within the range up to the specified distance from the right demarcation line to the right, the right shoulder width is identified as zero.
It was configured as follows:
Driving assistance device. The driving assistance device according to claim 1,
The acquisition unit is further configured to acquire a width of the lane,
The control unit is further configured to acquire a smaller target vehicle speed as the width of the lane becomes smaller.
Driving assistance device. In the driving assistance device according to any one of claims 1 and 2,
The acquisition unit is further configured to acquire an altitude of a current position of the vehicle,
The control unit is further configured to acquire a smaller target vehicle speed as the altitude increases.
Driving assistance device. The driving assistance device according to any one of claims 1 to 3,
The predetermined distance is preset to be smaller than 2.75 m.
Driving assistance device.

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