Driver assistance device, driver assistance method, and driver assistance program

Abstract

To provide a driving support device capable of improving comfort of an occupant of an own vehicle in a scene where a preceding vehicle makes a left or right turn.SOLUTION: A processor of the driving support device executes a mild deceleration process, in which a driving device and / or a braking device is controlled so that an own vehicle decelerates at a predetermined deceleration rate, or an acceleration suppression process, in which acceleration of the own vehicle is suppressed, in a first specific scene where the own vehicle and a preceding vehicle are traveling on a leftmost lane or a left-turn lane of a general road composed of multiple lanes, or on a general road composed of a single lane, and the preceding vehicle's direction indicator indicates a left turn while the preceding vehicle is not decelerating, and in a second specific scene where the own vehicle and the preceding vehicle are traveling on a rightmost lane or a right-turn lane of a general road composed of multiple lanes, or on a general road composed of a single lane, and the preceding vehicle's direction indicator indicates a right turn while the preceding vehicle is not decelerating.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a driving support device, a driving support method, and a driving support program for assisting a driving operation for adjusting the speed of a host vehicle by a driver of the host vehicle.

Background Art

[0002] A driving support device for assisting a driving operation for adjusting the speed of a host vehicle by a driver of the host vehicle has been proposed (for example, refer to Patent Document 1 below). This driving support device (hereinafter referred to as the "conventional device") is located immediately in front of the host vehicle and, in a scene where there is a preceding vehicle traveling in the same direction as the host vehicle, when it detects that the preceding vehicle is decelerating, it controls the drive device and / or the braking device of the host vehicle so that the host vehicle decelerates (automatic braking).

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

[0004] Incidentally, consider a scenario where a preceding vehicle is turning left (right), and that vehicle is traveling at a constant speed with its turn signal indicating a left (right) turn, and then begins to turn left (right) while decelerating. In this scenario, the conventional system does not perform automatic braking while the preceding vehicle is traveling at a constant speed. The conventional system then performs automatic braking when it detects that the preceding vehicle has begun to decelerate. Thus, when using the conventional system, the timing of the start of automatic braking (the timing when the vehicle itself begins to decelerate) is relatively late. If the driver and passengers of the vehicle are aware that the preceding vehicle's turn signal is activated, they are likely to predict that the preceding vehicle will decelerate afterward. In such a situation, the passengers may feel uneasy if the vehicle itself continues to travel without decelerating. Also, during this period, the distance between the vehicle itself and the preceding vehicle may decrease. In other words, there is a risk that the vehicle itself and the preceding vehicle will be in close proximity. In this case, the occupants of the vehicle may feel uneasy.

[0005] One of the objectives of the present invention is to provide a driver assistance device that can improve the comfort of the occupants of the vehicle when the preceding vehicle is turning left or right.

[0006] To solve the above problems, the driving assistance device (1) of the present invention is: An on-board sensor (20) that acquires information about the vehicle itself (V) and information about a preceding vehicle (V1) traveling in front of the vehicle, A processor (10) capable of performing a speed adjustment process to adjust the speed of the vehicle by controlling the drive unit (30) and / or braking unit (40) of the vehicle based on the information relating to the vehicle itself and / or the information relating to the preceding vehicle, It is equipped with. The aforementioned processor, In a first specific scene (SCN1) where the vehicle and the preceding vehicle are traveling in the leftmost lane (L) or left-turn lane (L) of a multi-lane public road, or on a public road consisting of a single lane (S), and the preceding vehicle's turn signal indicates a left turn and the preceding vehicle is not slowing down, and in a second specific scene (SCN2) where the vehicle is traveling in the rightmost lane or right-turn lane of a multi-lane public road, or on a public road consisting of a single lane, and the preceding vehicle's turn signal indicates a right turn and the preceding vehicle is not slowing down, the speed adjustment process is as follows: A gradual deceleration process that controls the drive and / or braking systems so that the vehicle decelerates at a predetermined deceleration rate, or Acceleration suppression process that controls the drive system and / or braking system so as to suppress the acceleration of the vehicle. Execute this.

[0007] Furthermore, the driving assistance method according to the present invention is An information acquisition step to acquire information about the vehicle itself and information about a preceding vehicle traveling in front of the vehicle, A speed adjustment step of adjusting the speed of the vehicle by controlling the drive system and / or braking system of the vehicle based on the information relating to the vehicle itself and / or the information relating to the preceding vehicle, Includes. The aforementioned speed adjustment step is, In a first specific scenario, the vehicle and the preceding vehicle are traveling in the leftmost lane or left-turn lane of a multi-lane public road, or on a single-lane public road, and the preceding vehicle's turn signal indicates a left turn, and the preceding vehicle is not slowing down. In a second specific scenario, the vehicle is traveling in the rightmost lane or right-turn lane of a multi-lane public road, or on a single-lane public road, and the preceding vehicle's turn signal indicates a right turn, and the preceding vehicle is not slowing down. In this scenario, the speed adjustment process is as follows: A gradual deceleration process that controls the drive and / or braking systems so that the vehicle decelerates at a predetermined deceleration rate, or Acceleration suppression process that controls the drive system and / or braking system so as to suppress the acceleration of the vehicle. This includes the step of performing the following.

[0008] Furthermore, the driving assistance program according to the present invention is The computer installed in the vehicle, An information acquisition step to acquire information about the vehicle itself and information about a preceding vehicle traveling in front of the vehicle, A speed adjustment step of adjusting the speed of the vehicle by controlling the drive system and / or braking system of the vehicle based on the information relating to the vehicle itself and / or the information relating to the preceding vehicle, Make it run. The aforementioned speed adjustment step is, In a first specific scenario, the vehicle and the preceding vehicle are traveling in the leftmost lane or left-turn lane of a multi-lane public road, or on a single-lane public road, and the preceding vehicle's turn signal indicates a left turn, and the preceding vehicle is not slowing down. In a second specific scenario, the vehicle is traveling in the rightmost lane or right-turn lane of a multi-lane public road, or on a single-lane public road, and the preceding vehicle's turn signal indicates a right turn, and the preceding vehicle is not slowing down. In this scenario, the speed adjustment process is as follows: A gradual deceleration process that controls the drive and / or braking systems so that the vehicle decelerates at a predetermined deceleration rate, or Acceleration suppression process that controls the drive system and / or braking system so as to suppress the acceleration of the vehicle. This includes the step of performing the following.

[0009] In the first and second specific scenes, the preceding vehicle is not decelerating, but there is a high probability that the preceding vehicle will begin to decelerate afterward. Therefore, the processor performs either a gradual deceleration process or an acceleration suppression process in the first and second specific scenes. If the processor performs a gradual deceleration process, the distance between the vehicle and the preceding vehicle increases. If the processor performs an acceleration suppression process, the reduction in the distance between the vehicle and the preceding vehicle is suppressed. In other words, according to the present invention, a relatively large distance can be secured between the vehicle and the preceding vehicle in the specific scene. Therefore, it is possible to suppress feelings of anxiety among the occupants. Furthermore, if the preceding vehicle begins to decelerate afterward, the vehicle can decelerate with ample margin. That is, the deceleration (backward acceleration) of the vehicle is small. In this way, according to the present invention, the comfort of the vehicle's occupants can be improved compared to when using conventional devices.

[0010] In a driving support device according to one aspect of the present invention, The processor terminates the execution of the gradual deceleration process or the acceleration suppression process at a second time point, which is a predetermined time (Δtth) after the first time point in which the execution of the gradual deceleration process or the acceleration suppression process was started in the first specific scene and the second specific scene.

[0011] In the first and second specific scenes, if the preceding vehicle is traveling at a constant speed for a relatively long time, or if the preceding vehicle is accelerating for a relatively long time, the distance between your vehicle and the preceding vehicle may become excessively large. According to this embodiment, since an upper limit is defined for the time during which gradual deceleration processing or acceleration suppression processing is performed, the excessively large distance between your vehicle and the preceding vehicle is suppressed.

[0012] In another aspect of the present invention, in a driving support device, The aforementioned processor, In a scene other than the first specific scene and the second specific scene, as the speed adjustment process, a follow-up process is executed to adjust the speed of the host vehicle so that the distance between the host vehicle and the preceding vehicle matches a target value determined based on the speeds (vs, vs1) of the host vehicle and the preceding vehicle.

[0013] When the preceding vehicle starts decelerating in the first specific scene and the second specific scene, and then the distance between the host vehicle and the preceding vehicle becomes smaller than the target value, the processor controls the drive device and / or the braking device so that the host vehicle decelerates. That is, the host vehicle is automatically braked. In the first specific scene and the second specific scene, since a relatively large distance is ensured between the host vehicle and the preceding vehicle, in this automatic braking, the host vehicle can be decelerated with a margin. That is, the deceleration (backward acceleration) of the host vehicle is small. According to this, it is possible to suppress the comfort of the occupants of the host vehicle from being impaired.

Brief Description of the Drawings

[0014] [Figure 1] FIG. 1 is a block diagram of a driving support device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view showing a first example (A) and a second example (B) of a specific scene. [Figure 3] FIG. 3 is a plan view showing a third example (A) and a fourth example (B) of a specific scene. [Figure 4] FIG. 4 is a plan view showing a fifth example (A) and a sixth example (B) of a specific scene. [Figure 5] FIG. 5 is a plan view showing a seventh example (A) and an eighth example (B) of a specific scene. [Figure 6] FIG. 6 is a flowchart of a first program executed by the CPU to realize the deceleration mitigation function. [Figure 7] FIG. 7 is a flowchart of a second program executed by the CPU to realize the deceleration mitigation function.

Mode for Carrying Out the Invention

[0015] (Summary) As shown in Figure 1, the driver assistance device 1 according to one embodiment of the present invention is applied to a vehicle V equipped with an automatic driving function (hereinafter referred to as "the vehicle"). The driver assistance device 1 has a function (speed adjustment function) that assists the driver of the vehicle in adjusting the speed of the vehicle when the automatic driving function is disabled.

[0016] (Specific configuration) As shown in Figure 1, the driver assistance system 1 includes an ECU 10, an on-board sensor 20, a drive unit 30, and a braking unit 40.

[0017] The ECU10 comprises a microcomputer including a CPU10a, ROM10b (rewritable non-volatile memory), RAM10c, and timer10d. The CPU implements various functions by executing programs (instructions) stored in the ROM. The ECU10 is connected to other ECUs via CAN (Controller Area Network).

[0018] The on-board sensor 20 includes a camera 21 and a millimeter-wave radar 22 as sensors for acquiring information about a preceding vehicle V1 located in front of the vehicle.

[0019] Camera 21 is equipped with an imaging device and an image analysis device. The imaging device incorporates, for example, a CCD. The imaging device is installed at the front of the vehicle and directed forward. The imaging device captures the area in front of the vehicle at a predetermined frame rate and acquires image data. The image analysis device acquires the image data from the imaging device and analyzes the image data to recognize (identify) objects present within the field of view. The image analysis device recognizes, for example, lane markings (lane markings) and road signs (for example, signs indicating left-turn lanes, right-turn lanes, etc.). The image analysis device also recognizes, for example, a preceding vehicle V1 located in the section immediately in front of the vehicle in the lane it is traveling in. Furthermore, the image analysis device recognizes, for example, the operating state of the turn signals of the preceding vehicle V1 (the state of the turn signal lights). The image analysis device provides these recognition results to the ECU 10.

[0020] The millimeter-wave radar 22 includes a transmitting / receiving unit and a signal processing unit. The transmitting / receiving unit radiates millimeter-wave radio waves (hereinafter referred to as "millimeter waves") into the area surrounding the vehicle (in front of the vehicle) and receives millimeter waves (reflected waves) reflected by three-dimensional objects located within that area. The signal processing unit acquires various information about each reflection point of the millimeter waves based on physical quantities such as the time from when the transmitting / receiving unit radiates the millimeter waves until the reflected waves are received, the attenuation level of the reflected waves, and the difference between the frequency of the radiated millimeter waves and the frequency of the received reflected waves. For example, the signal processing unit calculates the position of each reflection point (relative position (direction and distance) with respect to the transmitting / receiving unit). The signal processing unit also calculates the velocity (relative velocity) of each reflection point with respect to the vehicle. The results of this calculation (data showing the distribution of reflection points (position and velocity of each reflection point with respect to the vehicle)) are then provided to the ECU 10.

[0021] Here, the field of view (imaging range) of camera 21 and the field of view (area where millimeter waves are emitted) of millimeter-wave radar 22 overlap. Based on fusion information obtained by integrating the information acquired from camera 21 and the information acquired from millimeter-wave radar 22, ECU 10 can acquire information about targets located in front of the vehicle, the position of the object relative to the vehicle (relative position), the velocity of the object relative to the vehicle (relative velocity), etc.

[0022] The on-board sensor 20 further includes a vehicle speed sensor 23 and an acceleration sensor 24, which are sensors for acquiring information about the behavior of the vehicle.

[0023] The vehicle speed sensor 23 includes a rotation speed measurement circuit and a speed calculation device. The rotation speed measurement circuit includes a pulse generation circuit that outputs a pulse (electrical signal) each time the vehicle's wheels rotate by a predetermined angle, and a counter circuit that counts the number of such pulses. The speed calculation device acquires the output value (number of pulses) of the counter circuit at predetermined intervals (each unit of time elapsed) and resets the count value to "0". In this way, the speed calculation device acquires the number of wheel rotations N per unit time. The speed calculation device acquires the vehicle's speed vs (speed in the longitudinal direction (absolute value)) by multiplying the rotation speed N by a coefficient k. The speed calculation device then provides the acquired speed vs to the ECU 10. The ECU 10 acquires the relative speed vr between the preceding vehicle V1 and the vehicle itself based on information acquired from the camera 21 and the millimeter-wave radar 22. The ECU 10 also acquires the speed vs (speed relative to the road surface) from the vehicle speed sensor 23. The ECU10 can obtain the speed vs1 of the preceding vehicle V1 (speed relative to the road surface vs1 = vr + vs) based on the relative speed vr and speed vs.

[0024] The acceleration sensor 24 includes a piezoelectric element. When the vehicle accelerates or decelerates in the longitudinal direction, the piezoelectric element deforms in the longitudinal direction of the vehicle, and the output voltage of the piezoelectric element changes with this deformation. The acceleration sensor 24 acquires the longitudinal acceleration of the vehicle based on the output voltage of the piezoelectric element. The acceleration sensor 24 then provides these accelerations to the ECU 10.

[0025] The on-board sensor 20 further includes a navigation system 25, which is a sensor for acquiring information about the road on which the vehicle and the preceding vehicle V1 are traveling. The navigation system 25 acquires the vehicle's position (latitude and longitude) based on GPS signals. The navigation system 25 also stores map information. The map information includes information about the type of road (general road or highway) and information about the lanes that make up the road (number of lanes, left-turn lane, right-turn lane, etc.). Based on the vehicle's position and the map information, the navigation system 25 acquires information about the type of road and the lanes on which the vehicle is traveling and provides this information to the ECU 10.

[0026] The drive unit 30 generates a driving force and applies this driving force to the drive wheels among the wheels (left front wheel, right front wheel, left rear wheel, and right rear wheel). The drive unit 30 includes an engine ECU, an internal combustion engine, a transmission, etc. The engine ECU obtains a target value for the driving force from the ECU 10. The engine ECU controls the throttle valve (opening degree of the solenoid valve) of the internal combustion engine so that the driving force applied to the drive wheels matches the target value. The output (driving force) of the internal combustion engine is transmitted to the drive wheels via the transmission and a power transmission mechanism (e.g., a drive shaft).

[0027] If the vehicle is a hybrid electric vehicle (HEV), the engine ECU adjusts the driving force generated by either the internal combustion engine or the electric motor, or both, to match the target value. If the vehicle is a battery electric vehicle (BEV), the electric motor ECU can be used instead of the engine ECU. The electric motor ECU adjusts the driving force generated by the electric motor, which is the vehicle's driving source, to match the target value.

[0028] The braking system 40 applies braking force to the wheels. The braking system 40 includes a brake ECU, a hydraulic circuit, and a brake caliper. The hydraulic circuit includes a reservoir (not shown), an oil pump, various valve devices, a hydraulic sensor, etc. The brake caliper is a hydraulic actuator with a cylinder and a piston. When oil is supplied to the cylinder, the piston is pushed out of the cylinder. A brake pad is provided at the tip of the piston, and this brake pad is pressed against the brake disc. The brake ECU obtains a target value for braking force from the ECU 10. The brake ECU controls the hydraulic circuit so that the braking force applied to the wheels matches the target value.

[0029] (Speed ​​adjustment function) If the ECU 10 determines that a preceding vehicle V1 exists, it executes a follow-up process that controls the drive unit 30 and / or braking unit 40 (hereinafter referred to as "drive unit, etc.") so that the distance between the own vehicle and the preceding vehicle V1 (inter-vehicle distance D) matches the target value Dd, and the speed vs of the own vehicle follows the speed vs1 of the preceding vehicle V1. Hereinafter, this function will be referred to as the "follow-up function." However, if certain conditions are met, the ECU 10 executes a gradual deceleration process that controls the drive unit, etc. so that the own vehicle decelerates gradually, instead of the follow-up process. Hereinafter, this function will be referred to as the "gradual deceleration function."

[0030] (Follow function) Based on information acquired from the camera 21 and the millimeter-wave radar 22, the ECU 10 sequentially acquires the distance D between the preceding vehicle V1 and its own vehicle, and the relative speed vr. Furthermore, the ECU 10 sequentially acquires the speed vs of its own vehicle from the vehicle speed sensor 23. Based on the relative speed vr and speed vs (speed relative to the road surface), the ECU 10 acquires the speed vs1 (speed relative to the road surface) of the preceding vehicle V1. Based on the speed vs of its own vehicle and the speed vs1 of the preceding vehicle V1, the ECU 10 determines a target value Dd for the distance D between the vehicles.

[0031] When the relative velocity vr is greater than "0", the distance between vehicles D increases. When the distance between vehicles D is greater than the target value Dd, the ECU 10 sets the target value of the vehicle's acceleration α (rate of increase in forward speed) to a predetermined value α1 (>0) so that the vehicle's speed vs is greater than the speed vs1 of the preceding vehicle V1. Then, the ECU 10 controls the drive system etc. so that the vehicle's acceleration α (measured value) matches the predetermined value α1 (acceleration processing). As a result, the distance between vehicles D decreases and approaches the target value Dd. When the distance between vehicles D matches the target value Dd, the ECU 10 sets the target value of the vehicle's acceleration α to "0". Then, the ECU 10 controls the drive system etc. so that the vehicle travels at the same speed as the preceding vehicle V1.

[0032] On the other hand, when the relative speed vr is less than "0", the distance between vehicles D decreases. When the distance between vehicles D is smaller than the target value Dd, the ECU 10 sets the target value of deceleration β (backward acceleration) to a predetermined value β1 so that the speed vs of the vehicle itself is less than the speed vs1 of the preceding vehicle V1. The deceleration β corresponds to the rate of decrease in the forward speed of the vehicle itself. The ECU 10 controls the drive system, etc., so that the deceleration β (measured value) of the vehicle itself matches the predetermined value β1 (deceleration process). As a result, the distance between vehicles D increases and approaches the target value Dd. When the distance between vehicles D matches the target value Dd, the ECU 10 sets the target value of the deceleration β of the vehicle itself to "0". The ECU 10 then controls the drive system, etc., so that the vehicle itself travels at the same speed as the preceding vehicle V1.

[0033] The target value Dd is correlated with the vehicle's speed vs and the speed vs1 of the preceding vehicle V1. For example, the target value Dd when speed vs and speed vs1 are relatively small is smaller than the target value Dd when speed vs and speed vs1 are relatively large. A database (table) representing the relationship between speed vs, vs1 and the target value Dd, or parameters defining the calculation formula for calculating the target value Dd, is stored in ROM10b. The ECU10 determines the target value Dd based on the above database or calculation formula.

[0034] (Slow deceleration function) The ECU 10 sequentially determines whether the following conditions X1 or X2 are met based on the information obtained from the on-board sensor 20. [Condition X1]...The vehicle and the preceding vehicle V1 are traveling in the leftmost lane L of a public road consisting of multiple lanes, or on a public road consisting of a single lane S, and the preceding vehicle V1's turn signal is indicating a left turn (the left turn signal is flashing), and the preceding vehicle V1 is not slowing down (see Figures 2(A), 3(A), and 4(A)). [Condition X2]...The vehicle and the preceding vehicle V1 are traveling in the rightmost lane R of a public road consisting of multiple lanes, or on a public road consisting of a single lane S, and the preceding vehicle V1's turn signal is indicating a right turn (the right turn signal is flashing), and the preceding vehicle V1 is not slowing down (see Figures 2(B), 3(B), and 4(B)).

[0035] Here, as shown in Figure 5(A), the ECU 10 considers a left-turn lane (a lane exclusively for left turns at an intersection or a lane where left turns are permitted) as lane L (the leftmost lane) among a road composed of multiple lanes. Also, as shown in Figure 5(B), the ECU 10 considers a right-turn lane (a lane exclusively for right turns at an intersection or a lane where right turns are permitted) as lane R (the rightmost lane) among a road composed of multiple lanes.

[0036] In the first specific scene SCN1 where condition X1 is met and the second specific scene SCN2 where condition X2 is met, the ECU10 performs a gradual deceleration process instead of a follow process. Specifically, in the first specific scene SCN1 and the second specific scene SCN2, the ECU10 controls the drive system, etc., so that the deceleration β (reverse acceleration) of the own vehicle matches a relatively small target value βd (<β1) (gradual deceleration process). As described above, in the first specific scene SCN1 and the second specific scene SCN2, the preceding vehicle V1 is not decelerating (it is driving at a constant speed or accelerating), and the own vehicle is decelerating gradually. Therefore, the distance D between vehicles increases, but in the first specific scene SCN1 and the second specific scene SCN2, the increase in the distance D between vehicles is permissible.

[0037] The ECU 10 measures the time Δt that has elapsed since the start of the gradual deceleration process at time t1. When the time Δt reaches the threshold Δtth at time t2, the ECU 10 terminates the execution of the gradual deceleration process and resumes the following process. Here, the threshold Δtth is a value predetermined as the standard time from when the preceding vehicle's turn signal starts to activate until the preceding vehicle starts to decelerate. However, if the ECU 10 detects that the preceding vehicle V1 has started to decelerate while the gradual deceleration process is being executed, it terminates the execution of the gradual deceleration process at that point and resumes the following process. Furthermore, even if the turn signal of the preceding vehicle V1 stops activating while the gradual deceleration process is being executed, the ECU 10 continues to execute the gradual deceleration process until time t2. However, the ECU 10 may terminate the execution of the gradual deceleration process and resume the following process when the turn signal of the preceding vehicle V1 stops activating.

[0038] Next, referring to Figures 6 and 7, we will explain programs PR1 and PR2, which are executed by the CPU 10a (hereinafter referred to as "CPU") of the ECU 10 to realize the above-mentioned gradual deceleration function. Here, programs PR1 and PR2 use a flag F. Flag F indicates whether or not the execution of the follow process (acceleration process and deceleration process) is permitted. When the execution of the acceleration process and deceleration process is permitted, flag F is set to "1", and when the execution of the acceleration process and deceleration process is prohibited, flag F is set to "0". Note that when the ignition switch of the vehicle transitions from the off state to the on state, flag F is initialized to "1".

[0039] When the ignition switch is ON, the CPU starts executing programs PR1 and PR2 at predetermined intervals.

[0040] (Program PR1) The CPU starts executing program PR1 from step 100 and proceeds to step 101.

[0041] In step 101, the CPU determines whether the vehicle is traveling on a public road based on information obtained from the navigation system 25. If the CPU determines that the vehicle is traveling on a public road (101: Yes), it proceeds to step 102. On the other hand, if the CPU does not determine that the vehicle is traveling on a public road (101: No), it proceeds to step 112, and in step 112, it terminates the execution of program PR1.

[0042] In step 102, the CPU determines whether the vehicle is traveling in lane L or lane S based on information obtained from the navigation system 25. If the CPU determines that the vehicle is traveling in lane L or lane S (102: Yes), it proceeds to step 103. On the other hand, if the CPU does not determine that the vehicle is traveling in lane L or lane S (102: No), it proceeds to step 112, and in step 112, it terminates the execution of program PR1.

[0043] In step 103, the CPU determines, based on the information obtained from camera 21, whether the turn signal of the preceding vehicle V1 indicates a left turn (whether the left turn signal is flashing or not). If the CPU determines that the turn signal of the preceding vehicle V1 indicates a left turn (103: Yes), it proceeds to step 104. On the other hand, if the CPU does not determine that the turn signal of the preceding vehicle V1 indicates a left turn (103: No), it proceeds to step 112, and in step 112, it terminates the execution of program PR1.

[0044] In step 104, the CPU obtains the speed vs1 of the preceding vehicle V1 based on information acquired from the camera 21, millimeter-wave radar 22, and vehicle speed sensor 23. The CPU then determines whether the speed vs1 of the preceding vehicle V1 is constant or increasing based on the change in speed vs1 (time-series data of speed vs1). If the CPU determines that the speed vs1 of the preceding vehicle V1 is constant or increasing (104: Yes), it proceeds to step 105. On the other hand, if the CPU does not determine that the speed vs1 of the preceding vehicle V1 is constant or increasing (104: No), it proceeds to step 112, and in step 112, it terminates the execution of program PR1.

[0045] In step 105, the CPU sets flag F to "0". That is, the CPU interrupts the tracking process (prohibiting the execution of acceleration and deceleration processes). Next, the CPU proceeds to step 106.

[0046] In step 106, the CPU begins the gradual deceleration process. Next, the CPU proceeds to step 107.

[0047] In step 107, the CPU uses timer 10d to start measuring the time Δt that has elapsed since the start of the gradual deceleration process. Next, the CPU proceeds to step 108.

[0048] In step 108, the CPU obtains the speed vs1 of the preceding vehicle V1 based on information acquired from the millimeter-wave radar 22 and the vehicle speed sensor 23. The CPU then determines whether the speed vs1 is decreasing (whether the preceding vehicle V1 has started to decelerate) based on the time-series data of the speed vs1. If the CPU determines that the speed vs1 of the preceding vehicle V1 is decreasing (108: Yes), it proceeds to step 110. On the other hand, if the CPU does not determine that the speed vs1 of the preceding vehicle V1 is decreasing (108: No), it proceeds to step 109.

[0049] In step 109, the CPU determines whether time Δt exceeds the threshold Δtth. If the CPU determines that time Δt exceeds the threshold Δtth (109: Yes), it proceeds to step 110. On the other hand, if the CPU does not determine that time Δt exceeds the threshold Δtth (109: No), it returns to step 108. In other words, in this case, the CPU continues the gradual deceleration process.

[0050] In step 110, the CPU finishes executing the gradual deceleration process. Next, the CPU proceeds to step 111.

[0051] In step 111, the CPU sets flag F to "1". That is, the CPU resumes tracking (permits the execution of acceleration and deceleration processes). Next, the CPU proceeds to step 112, in which step 112 terminates the execution of program PR1.

[0052] (Program PR2) The CPU starts executing program PR2 from step 200 and proceeds to step 201.

[0053] In step 201, the CPU determines whether the vehicle is traveling on a public road based on information obtained from the navigation system 25. If the CPU determines that the vehicle is traveling on a public road (201: Yes), it proceeds to step 202. On the other hand, if the CPU does not determine that the vehicle is traveling on a public road (201: No), it proceeds to step 212, and in step 212, it terminates the execution of program PR2.

[0054] In step 202, the CPU determines whether the vehicle is traveling in lane R or lane S based on information obtained from the navigation system 25. If the CPU determines that the vehicle is traveling in lane R or lane S (202: Yes), it proceeds to step 203. On the other hand, if the CPU does not determine that the vehicle is traveling in lane R or lane S (202: No), it proceeds to step 212, and in step 212, it terminates the execution of program PR2.

[0055] In step 203, the CPU determines, based on the information obtained from camera 21, whether the turn signal of the preceding vehicle V1 indicates a right turn (whether the right turn signal is flashing or not). If the CPU determines that the turn signal of the preceding vehicle V1 indicates a right turn (303: Yes), it proceeds to step 204. On the other hand, if the CPU does not determine that the turn signal of the preceding vehicle V1 indicates a right turn (203: No), it proceeds to step 212, and in step 212, it terminates the execution of program PR2.

[0056] Steps 204 through 212 are identical to steps 104 through 112 of program PR1, so their explanations will be omitted.

[0057] Furthermore, when flag F is "1", the CPU executes a program (not shown) to implement the tracking function described above. This program includes the steps of determining a target value Dd for the distance between vehicles D based on speed vs and speed vs1, and accelerating (accelerating) or decelerating (deceleration) the vehicle so that the distance between vehicles D (measured value) matches the target value Dd.

[0058] (effect) In the first specific scene SCN1 and the second specific scene SCN2, the preceding vehicle V1 is not decelerating, but there is a high probability that the preceding vehicle V1 will start to decelerate afterward. Therefore, the ECU 10 performs a gradual deceleration process in the first specific scene SCN1 and the second specific scene SCN2. This increases the distance D between vehicles. In other words, a relatively large distance D can be secured in the first specific scene SCN1 and the second specific scene SCN2. As a result, it is possible to suppress the feeling of anxiety that may arise in the occupants. Furthermore, if the preceding vehicle V1 starts to decelerate afterward, the vehicle can decelerate with ample margin. As described above, according to this embodiment, the comfort of the occupants of the vehicle can be improved compared to when using a conventional device.

[0059] The present invention is not limited to the embodiments described above, and various modifications can be adopted within the scope of the present invention, as described below.

[0060] <Example 1> Instead of the gradual deceleration process in the above embodiment, an acceleration suppression process may be performed to control the drive unit 30 and / or braking unit 40 so as to suppress the acceleration of the vehicle (increase in speed vs). For example, in the first specific scene SCN1 and the second specific scene SCN2, even if the driver presses the accelerator pedal, the ECU 10 does not increase the target value of the driving force.

[0061] <Modification 2> In the above embodiment, the ECU 10 can perform acceleration and deceleration processing in the follow-up process, but alternatively, it may only perform deceleration processing in the follow-up process. That is, in scenes other than the first specific scene SCN1 and the second specific scene SCN2, it may be permissible for the distance D between vehicles to increase above the target value Dd. [Explanation of Symbols]

[0062] 1…Driving assistance system, 10…ECU, 20…On-board sensor, 30…Drive system, 40…Braking system

Claims

1. An on-board sensor that acquires information about the vehicle itself and information about a preceding vehicle traveling in front of the vehicle, A processor capable of performing a speed adjustment process to adjust the speed of the vehicle by controlling the drive system and / or braking system of the vehicle based on the information relating to the vehicle itself and / or the information relating to the preceding vehicle, A driver assistance device equipped with, The aforementioned processor, In a first specific scenario, the vehicle and the preceding vehicle are traveling in the leftmost lane or left-turn lane of a multi-lane public road, or on a single-lane public road, and the preceding vehicle's turn signal indicates a left turn, and the preceding vehicle is not slowing down. In a second specific scenario, the vehicle is traveling in the rightmost lane or right-turn lane of a multi-lane public road, or on a single-lane public road, and the preceding vehicle's turn signal indicates a right turn, and the preceding vehicle is not slowing down. In this scenario, the speed adjustment process is as follows: A gradual deceleration process that controls the drive system and / or braking system so that the vehicle decelerates at a predetermined deceleration rate, or Acceleration suppression process that controls the drive system and / or braking system so as to suppress the acceleration of the vehicle. Execute, Even if the turn signal of the preceding vehicle is stopped operating while the aforementioned gradual deceleration process or acceleration suppression process is being performed, A driving support device configured to continue the gradual deceleration process or the acceleration suppression process from a first point in time when the execution of the gradual deceleration process or the acceleration suppression process is started until a second point in time when a predetermined period of time has elapsed.

2. In the driving support device according to claim 1, The processor is configured to terminate the execution of the acceleration suppression process or the gradual deceleration process at a second time point, after a predetermined time has elapsed from the first time point at which the execution of the acceleration suppression process or the gradual deceleration process was started, in the first specific scene and the second specific scene.

3. In the driving support device according to claim 1 or claim 2, The aforementioned processor, A driving assistance device configured to perform a following process as the speed adjustment process in scenes other than the first specific scene and the second specific scene, in which the speed of the vehicle adjusts the speed of the vehicle so that the distance between the vehicle and the preceding vehicle matches a target value determined based on the speeds of the vehicle and the preceding vehicle.

4. An information acquisition step to acquire information about the vehicle itself and information about a preceding vehicle traveling in front of the vehicle, A speed adjustment step of adjusting the speed of the vehicle by controlling the drive system and / or braking system of the vehicle based on the information relating to the vehicle itself and / or the information relating to the preceding vehicle, A driving assistance method that includes, The aforementioned speed adjustment step is, In a first specific scenario, the vehicle and the preceding vehicle are traveling in the leftmost lane or left-turn lane of a multi-lane public road, or on a single-lane public road, and the preceding vehicle's turn signal indicates a left turn, and the preceding vehicle is not slowing down. In a second specific scenario, the vehicle is traveling in the rightmost lane or right-turn lane of a multi-lane public road, or on a single-lane public road, and the preceding vehicle's turn signal indicates a right turn, and the preceding vehicle is not slowing down. In the speed adjustment step, A gradual deceleration process that controls the drive system and / or braking system so that the vehicle decelerates at a predetermined deceleration rate, or Acceleration suppression process that controls the drive system and / or braking system so as to suppress the acceleration of the vehicle. Includes the step of performing, Even if the turn signal of the preceding vehicle is stopped operating while the aforementioned gradual deceleration process or acceleration suppression process is being performed, A driving assistance method configured to include a step of continuing the gradual deceleration process or the acceleration suppression process from a first point in time when the execution of the gradual deceleration process or the acceleration suppression process is started until a second point in time when a predetermined period of time has elapsed.

5. The computer installed in the vehicle, An information acquisition step to acquire information about the vehicle itself and information about a preceding vehicle traveling in front of the vehicle, A speed adjustment step of adjusting the speed of the vehicle by controlling the drive system and / or braking system of the vehicle based on the information relating to the vehicle itself and / or the information relating to the preceding vehicle, A driver assistance program that enables the execution of, The aforementioned speed adjustment step is, In a first specific scenario, the vehicle and the preceding vehicle are traveling in the leftmost lane or left-turn lane of a multi-lane public road, or on a single-lane public road, and the preceding vehicle's turn signal indicates a left turn, and the preceding vehicle is not slowing down. In a second specific scenario, the vehicle is traveling in the rightmost lane or right-turn lane of a multi-lane public road, or on a single-lane public road, and the preceding vehicle's turn signal indicates a right turn, and the preceding vehicle is not slowing down. In the speed adjustment step, A gradual deceleration process that controls the drive system and / or braking system so that the vehicle decelerates at a predetermined deceleration rate, or Acceleration suppression process that controls the drive system and / or braking system so as to suppress the acceleration of the vehicle. Includes the step of performing, Even if the turn signal of the preceding vehicle is stopped operating while the aforementioned gradual deceleration process or acceleration suppression process is being performed, A driving assistance program configured to include a step of continuing the gradual deceleration process or the acceleration suppression process from a first point in time when the execution of the gradual deceleration process or the acceleration suppression process is started until a second point in time when a predetermined period of time has elapsed.

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