Driver assistance system, vehicle, driver assistance method, and driver assistance program

Abstract

The present invention provides a driving assistance device that supports the operation of starting a vehicle, and which can temporarily suppress the acceleration of the vehicle at the time of starting, in accordance with the driver's request. [Solution] The driver assistance device 1 includes a processor that is capable of performing cruise control to control the vehicle so that it follows a preceding vehicle, performs stop control to stop the vehicle when a predetermined stopping condition is met while the cruise control is being performed, and performs start control to start the vehicle by controlling the vehicle so that its acceleration matches a first predetermined value when a predetermined start operation is performed thereafter. After performing the start control, if the processor detects that a predetermined first accelerator pedal operation indicating suppression of the vehicle's acceleration has been performed, it performs acceleration suppression control to control the vehicle so that its acceleration matches a second predetermined value which is smaller than the first predetermined value.

Description

Technical Field

[0001] The present invention relates to a driving assistance device that assists a driving operation for adjusting the speed of a host vehicle , vehicles, driving assistance methods and driving assistance programs . Background Art

[0002] Driving assistance devices that assist a driving operation for adjusting the speed of a host vehicle have been proposed (see, for example, Patent Document 1 below). This driving assistance device (hereinafter referred to as "conventional device") is capable of executing cruise control that controls the host vehicle (a drive device, a braking device, etc.) so that the host vehicle travels at a preset speed when a predetermined condition is satisfied. Prior Art Documents Patent Documents

[0003] Patent Document 1 Japanese Unexamined Patent Application Publication No. 2011-241872 Summary of the Invention

[0004] This type of conventional device is configured to control a drive device or the like of the host vehicle so as to follow another vehicle (preceding vehicle) traveling immediately ahead of the host vehicle when such a preceding vehicle exists. When the preceding vehicle stops, the conventional device stops the host vehicle behind the preceding vehicle. Thereafter, when the preceding vehicle starts moving and the driver of the host vehicle performs a predetermined operation, the conventional device starts the host vehicle such that the host vehicle follows the preceding vehicle. At that time, the conventional device controls the drive device or the like such that the acceleration of the host vehicle matches a preset value. If the driver (an occupant) feels that the acceleration of the host vehicle is too large (the acceleration is too abrupt) and depresses the brake pedal, the cruise control is interrupted. Therefore, after that, the driver has to personally perform the driving operation for adjusting the speed of the host vehicle.

[0005] One of the objectives of the present invention is a device that assists in the driving operation of starting a vehicle, and which, in response to the driver's request, controls the acceleration of the vehicle at the time of starting It is possible to change Driving assistance systems , vehicles, driving assistance methods and driving assistance programs The objective is to provide.

[0006] To achieve the above objective, the driving assistance device (1) of the present invention is: nine Loose control is possible, and if a predetermined stopping condition is met while the cruise control is being performed, stop control is performed to bring the vehicle to a stop, and then a predetermined start is performed. The conditions are met. The system includes a processor (10) configured to perform a starting control that controls the vehicle so that the vehicle's acceleration (α) matches a first predetermined value (αacc) and starts the vehicle. After the starting control is performed, the processor prescribed When it is detected that an operation has been performed, the acceleration of the vehicle reaches the first predetermined value. Change from ru.

[0007] This invention The vehicles consist of vehicles equipped with the driver assistance device of the present invention. .

[0008] This invention The driving assistance method includes: the processor executing a stop control to stop the vehicle when predetermined stopping conditions are met while cruise control is being performed; the processor executing a start control to start the vehicle after the stop control has been performed, when predetermined starting conditions are met, by controlling the vehicle so that its acceleration matches a first predetermined value; and the processor executing a control to change the vehicle's acceleration from the first predetermined value when it detects that a predetermined operation has been performed after the start control has been performed. .

[0009] The driver assistance program of the present invention causes the computer to perform the following processes: a process to perform stop control to stop the vehicle when predetermined stopping conditions are met while cruise control is being performed; a process to perform start control to start the vehicle after the stop control has been performed, when predetermined starting conditions are met, by controlling the vehicle so that the vehicle's acceleration matches a first predetermined value; and a process to perform control to change the vehicle's acceleration from the first predetermined value when it is detected that a predetermined operation has been performed after the start control has been performed. . [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a block diagram of a driver assistance device according to one embodiment of the present invention. [Figure 2] Figure 2 is a graph showing the changes in the vehicle's speed, acceleration, and accelerator pedal depression depth. [Figure 3] Figure 3 is a flowchart of the first program executed by the CPU to implement the ACC function. [Figure 4] Figure 4 is a flowchart of the second program executed by the CPU to implement the ACC function. [Figure 5]Figure 5 is a flowchart of the third program executed by the CPU to implement the ACC function. [Figure 6] Figure 6 is a flowchart of the fourth program executed by the CPU to implement the ACC function. [Modes for carrying out the invention]

[0011] (Outline) A driving assistance device 1 according to one embodiment of the present invention is applied, for example, to a vehicle V0 equipped with an autonomous driving function (hereinafter referred to as "the vehicle"). The driving assistance device 1 has a function to control the drive system of the vehicle so that, when a preceding vehicle V1 (a vehicle located directly in front of the vehicle) is stopped and the vehicle is stopped immediately behind it, the vehicle starts moving in accordance with the preceding vehicle V1 if predetermined conditions are met after the detection of the preceding vehicle V1 starting to move.

[0012] (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.

[0013] The ECU10 includes a microcomputer equipped with a CPU10a, ROM10b, RAM10c, timer10d, etc. The ECU10 is connected to other ECUs in the vehicle via CAN (Controller Area Network).

[0014] The on-board sensor 20 includes forward sensors that acquire information about the preceding vehicle V1. Specifically, the on-board sensor 20 includes a millimeter-wave radar 21, a sonar 22, and a forward camera 23 as forward sensors.

[0015] The millimeter wave radar 21 includes a transmission / reception unit and a signal processing unit (not shown in the figures). The transmission / reception unit radiates millimeter-wave band radio waves (hereinafter referred to as "millimeter waves") forward of the host vehicle, and receives millimeter waves (reflected waves) reflected by a three-dimensional object (preceding vehicle V1) located within the radiation range. The signal processing unit calculates the distance between the host vehicle and the three-dimensional object (e.g., preceding vehicle V1), the speed (relative speed) of the three-dimensional object, and the like based on the time from when the transmission / reception unit radiates the millimeter wave to when it receives the reflected wave, the phase difference between the transmitted millimeter wave and the received reflected wave, the attenuation level of the reflected wave, and the like, and transmits the calculation result to the ECU 10.

[0016] The sonar 22 intermittently radiates ultrasonic waves to the surrounding area of the host vehicle, and receives ultrasonic waves (reflected waves) reflected by a three-dimensional object. The sonar 22 calculates the distance between the host vehicle and the three-dimensional object, the position (direction) of the three-dimensional object relative to the host vehicle, and the like based on the time from when the ultrasonic wave is transmitted to when the reflected wave is received, and transmits the calculation result to the ECU 10.

[0017] The forward camera 23 includes an imaging device and an image analysis device. The imaging device incorporates a lens and an imaging element such as a CCD (charge coupled device) or a CIS (CMOS image sensor). The imaging device is oriented forward at the upper part of the front windshield glass. The imaging device photographs the foreground of the host vehicle at a predetermined frame rate to acquire image data, and transmits the image data to the image analysis device. The image analysis device analyzes the acquired image data, and acquires information related to objects located in front of the host vehicle from the image. For example, the image analysis device identifies (recognizes) the type of target located in front of the host vehicle (e.g., other vehicles, lane marks, etc.), and transmits the identification result to the ECU 10.

[0018] In addition, the on-vehicle sensors 20 include vehicle sensors that acquire information related to the behavior (speed and acceleration) of the host vehicle. Specifically, the on-vehicle sensors 20 include a speed sensor 24 and an acceleration sensor 25 serving as vehicle sensors.

[0019] The speed sensor 24 detects the rotational speed of each wheel (wheel speed), and calculates the speed sp0 (measured value) of the host vehicle based on each wheel speed. The speed sensor 24 transmits the calculation result to the ECU 10.

[0020] The acceleration sensor 25 detects acceleration α in the longitudinal direction of the host vehicle. The acceleration sensor 25 transmits the detection result to the ECU 10.

[0021] Further, the in-vehicle sensor 20 includes an accelerator pedal sensor 26 as an operation sensor. The accelerator pedal sensor 26 detects a depression depth AD of an accelerator pedal AP, and transmits the detection result to the ECU 10.

[0022] The driving device 30 applies driving force to drive wheels. The driving device 30 includes an engine ECU, an internal combustion engine, a transmission, a driving force transmission mechanism that transmits driving force to the wheels, and the like. The engine ECU acquires information representing a target driving force (target value) from another ECU (the ECU 10). The engine ECU drives a throttle valve of the internal combustion engine to make the driving force applied to the drive wheels match the target value. Output (driving force) of the internal combustion engine is transmitted to the drive wheels via the transmission and the driving force transmission mechanism.

[0023] Note that when a vehicle to which the driving support device 1 is applied is a hybrid vehicle (HEV), the engine ECU can adjust output (driving force) of either one or both of "the internal combustion engine and an electric motor" as vehicle driving sources. Further, when a vehicle to which the driving support device 1 is applied is a battery electric vehicle (BEV), a motor ECU that adjusts output (driving force) of "an electric motor" as a vehicle driving source is used instead of the engine ECU.

[0024] The braking system 40 applies braking force to the wheels (brake discs). The braking system 40 includes a brake ECU, brake calipers, etc. The brake calipers include actuators that press brake pads against the brake discs. The brake ECU obtains information (target value) representing the target braking force from other ECUs. The brake ECU drives the actuators of the brake calipers to match the braking force applied to the wheels (brake discs) to the target value.

[0025] (Operation) When the ACC switch (not shown) installed in the vehicle is ON, the ECU 10 determines whether or not there is a preceding vehicle V1, as described below, and controls the vehicle's drive unit 30 and braking unit 40 (hereinafter referred to as "drive unit, etc.") based on the determination result. This control may be referred to as adaptive cruise control (ACC). ACC includes constant speed driving control and distance keeping control.

[0026] [Constant Speed ​​Driving Control] The ECU 10 determines the presence or absence of a preceding vehicle V1 based on information acquired from the forward sensors (millimeter-wave radar 21, sonar 22, and forward camera 23). If no preceding vehicle V1 exists, the ECU 10 performs constant speed driving control. Specifically, the ECU 10 controls the drive system, etc., so that the vehicle's speed sp0 matches a predetermined target value spt (for example, a speed value set by the driver, or a speed value that results in the lowest fuel consumption rate). Even if a preceding vehicle V1 exists, if its speed sp1 is greater than the target value spt, the ECU 10 performs constant speed driving control.

[0027] [Distance Maintaining Control] On the other hand, if the ECU 10 determines that a preceding vehicle V1 exists and the speed sp1 of the preceding vehicle SP1 is less than the target value spt, it executes distance maintaining control. Specifically, the ECU 10 obtains the speed sp0 of its own vehicle from the speed sensor 24. Furthermore, based on the information obtained from the forward sensor and vehicle sensor, the ECU 10 obtains the distance D between the preceding vehicle V1 and the own vehicle, and the speed sp1 of the preceding vehicle V1. Based on the speed sp0 of the own vehicle and the speed sp1 of the preceding vehicle V1, the ECU 10 calculates the target value Dt for the distance D.

[0028] When the speed sp1 of the preceding vehicle V1 relative to the speed sp0 of the own vehicle (relative speed spr = sp1 - sp0) is greater than "0", the distance between vehicles D increases. When the distance between vehicles D is greater than the target value Dt, the ECU 10 assigns a predetermined value αacc (>0) to the target value αt of the acceleration α of the own vehicle so that the speed sp0 of the own vehicle is greater than the speed sp1 of the preceding vehicle V1. Then, it controls the drive system etc. so that the acceleration α (measured value) of the own vehicle matches the predetermined value αacc (acceleration control). As a result, the distance between vehicles D decreases and approaches the target value Dt. When the distance between vehicles D matches the target value Dt, the ECU 10 assigns "0" to the target value αt of the acceleration α of the own vehicle. In other words, the ECU 10 controls the drive system etc. so that the own vehicle travels at the same speed as the preceding vehicle V1.

[0029] On the other hand, when the relative velocity spr is less than "0", the distance between vehicles D decreases. When the distance between vehicles D is less than the target value Dt, the ECU 10 assigns a predetermined value αdec (<0) to the target value αt of acceleration α so that the speed sp0 of the vehicle itself is less than the speed sp1 of the preceding vehicle V1. The ECU 10 then controls the drive system, etc. (deceleration control) so that the acceleration α (measured value) of the vehicle itself matches the predetermined value αdec. As a result, the distance between vehicles D increases and approaches the target value Dt. When the distance between vehicles D matches the target value Dt, the ECU 10 assigns "0" to the target value αt of the acceleration α of the vehicle itself.

[0030] The target distance Dt is correlated with the vehicle's speed sp0 and the speed sp1 of the preceding vehicle V1. For example, the target value Dta when speeds sp0 and sp1 are relatively small is smaller than the target value Dtb when speeds sp0 and sp1 are relatively large. A database (table) representing the relationship between speeds sp0, sp1 and the target value Dt, or a calculation formula for determining the target value Dt, is stored in the ROM 10b. The ECU 10 determines the target value Dt based on the above database or calculation formula.

[0031] Furthermore, the predetermined values ​​αacc and αdec assigned to the target value αt of the acceleration α are fixed values ​​determined in advance. However, these predetermined values ​​αacc and αdec may be determined according to the inter-vehicle distance D (measured value). For example, it is preferable to set them so that the absolute values ​​of the predetermined values ​​αacc and αdec increase as the inter-vehicle distance D increases.

[0032] If the preceding vehicle V1 stops while the following distance maintenance control is being performed (sp1=0km / h (when the vehicle's stopping condition is met)), the following distance maintenance control will be executed, causing the vehicle to stop behind the preceding vehicle V1 (sp0=0km / h (stop control)). Subsequently, if the preceding vehicle V1 starts moving, the ECU 10 will not immediately start the vehicle to follow the preceding vehicle V1, but will keep the vehicle stopped until a predetermined starting operation is performed. When that starting operation is performed, the ECU 10 will execute starting control, which controls the drive system and other components so that the vehicle starts moving to follow the preceding vehicle V1.

[0033] [Start Control] The ECU 10 begins monitoring the behavior of the preceding vehicle V1 from the moment the vehicle comes to a stop behind the preceding vehicle V1. That is, the ECU 10 acquires various information from the forward sensors and, based on that information, sequentially determines whether or not the preceding vehicle V1 has started moving. For example, the ECU 10 determines that the preceding vehicle V1 has started moving when the speed sp1 of the preceding vehicle V1 acquired from the millimeter-wave radar 21 exceeds a predetermined threshold sp1th. Alternatively, for example, the ECU 10 may determine that the preceding vehicle V1 has started moving when the distance between the preceding vehicle V1 and the vehicle (inter-vehicle distance D) exceeds a threshold Dth.

[0034] After determining that the preceding vehicle V1 has started moving, the ECU 10 will start its own vehicle if it detects that the driver of its own vehicle has performed a predetermined starting operation (an operation that indicates the driver has the intention to start the vehicle). Specifically, the ECU 10 determines that the conditions for starting the vehicle have been met when the accelerator pedal AP is pressed down from a released state (AD = "0%), increasing the accelerator pedal depression depth AD to a predetermined value ADth1 (= "X%)". In this case, the ECU 10 controls the drive system etc. so that the acceleration α of the vehicle matches a predetermined value αacc (see Figure 2). As shown by the dashed lines in Figures 2(A) to 2(C), even if the driver releases the accelerator pedal AP after the vehicle has started moving, the ECU 10 will continue the starting control.

[0035] [Override Control] The driver of the vehicle may feel that the acceleration α (a predetermined value αacc) when the vehicle starts moving due to the start control is too low. If the driver then presses the accelerator pedal AP to accelerate the vehicle, override control is executed to rapidly accelerate the vehicle. Specifically, if the pedal depression depth AD exceeds a predetermined value ADth2 (=Y%>X%), the ECU 10 controls the drive system, etc., so that the acceleration α of the vehicle matches the value αover determined based on the pedal depression depth AD.

[0036] [Acceleration Suppression Control] On the other hand, there is a possibility that the driver of the own vehicle may feel that the acceleration α (predetermined value αacc) when the own vehicle starts by start control is too large. When the driver depresses the brake pedal to suppress sudden start of the own vehicle, the ECU 10 interrupts ACC. That is, the ECU 10 transitions the ACC switch to an off state. Therefore, thereafter, the driver needs to personally perform a driving operation to adjust the speed of the own vehicle. In addition, to resume ACC, the driver needs to press the ACC switch again. In order to eliminate such complicated operations, the driving assistance device 1 has a function of executing acceleration suppression control that controls a driving device or the like such that the acceleration α when the own vehicle starts becomes smaller than a value (αacc) set by normal start control. Note that the ECU 10 does not transition the ACC switch to the off state even when acceleration suppression control is started.

[0037] As described below, the ECU 10 executes acceleration suppression control when a condition for determining that the driver requests suppression of acceleration of the own vehicle is satisfied after detecting a start operation.

[0038] Specifically, the ECU 10 monitors the depression depth AD of the accelerator pedal AP from the time point when it is determined that a start operation has been performed, and sequentially determines whether a predetermined return operation (release operation) has been performed. As shown by the solid line in FIG. 2(C), when the ECU 10 detects that the depression depth AD has decreased to become equal to or less than a predetermined value ADth3 (=Z%<X%), the ECU 10 determines that the return operation has been performed. When the ECU 10 determines that the return operation has been performed, the ECU 10 continues to monitor the depression depth AD and sequentially determines whether a predetermined acceleration suppression operation has been performed. The ECU 10 determines that the acceleration suppression operation has been performed when the following condition A (a condition for determining that the accelerator pedal AP is lightly depressed) is satisfied. Condition A: In an orthogonal coordinate system (FIG. 2(D)) in which the horizontal axis represents a change rate (increase rate) ΔAD of the depression depth AD and the vertical axis represents the depression depth AD, a point P[ΔAD, AD] indicating the current values of both parameters is included in a predetermined range R. Here, as shown in Figure 2(D), range R is located to the left (inside) of the average trajectory T of point P when accelerating the vehicle at startup. That is, the lower end of range R in the vertical direction (deep press AD) is greater than "Z%". Also, the upper end of range R in the vertical direction (deep press AD) is less than "Y%". Furthermore, the right end of range R in the horizontal direction (rate of change ΔAD) is less than the maximum value (ΔADmax) of trajectory T. Also, the left end of range R in the horizontal direction (rate of change ΔAD) is infinitesimal.

[0039] When the ECU10 determines that an acceleration suppression operation has been performed, it controls the vehicle's drive system and other components so that the vehicle's acceleration α matches a predetermined value αsup, as shown in the practical example in Figure 2(A). Here, the predetermined value αsup is smaller than the predetermined value αacc, for example, about 1 / 4 of the predetermined value αacc.

[0040] Furthermore, the driver assistance device 1 prohibits the execution of acceleration suppression control after override control has been performed. Subsequently, when the vehicle comes to a stop again while ACC is in operation, the driver assistance device 1 makes acceleration suppression control possible.

[0041] Furthermore, after starting its own vehicle using the start control, the ECU 10 performs either constant speed driving control or distance keeping control according to the distance D between vehicles. For example, as shown in Figure 2(B), when the speed sp0 of the own vehicle reaches a predetermined target value spt, the ECU 10 sets the target value αt of acceleration α to "0" (constant speed driving control).

[0042] Next, referring to Figures 3 to 6, we will explain the programs PR1, PR2, PR3, and PR4 executed by the CPU 10a (hereinafter simply referred to as "CPU") to realize the above functions of the driver assistance device 1 (functions to perform start control, override control, and acceleration suppression control). In these programs, various flags are used. Flag Fs indicates whether the vehicle has started moving (whether the start operation has been performed). Flag Frel indicates whether the return operation has been performed. Flag Fdis indicates whether acceleration suppression control is prohibited. When the vehicle is stopped behind the preceding vehicle V1, the CPU initializes the various flags. Specifically, the CPU sets flag Fs to "0" to indicate that the vehicle has not started moving. The CPU also sets flag Frel to "0" to indicate that the return operation has not been performed. The CPU also sets flag Fdis to "0" to indicate that the execution of acceleration suppression control is not prohibited.

[0043] When the ACC switch is ON, the CPU executes programs PR1, PR2, PR3, and PR4 at predetermined intervals.

[0044] (Program PR1) The CPU starts executing Program PR1 from step 100 and proceeds to step 101.

[0045] In step 101, the CPU determines whether the preceding vehicle V1 has started moving from a state where both the own vehicle and the preceding vehicle V1 were stopped. The CPU determines that the preceding vehicle V1 has started moving if the distance ΔD between the vehicles exceeds the threshold ΔDth. If the CPU determines that the preceding vehicle V1 has started moving (101: Yes), it proceeds to step 102. On the other hand, if the CPU does not determine that the preceding vehicle V1 has started moving (101: No), it proceeds to step 105, and in step 105, it terminates the execution of program PR1.

[0046] In step 102, the CPU determines whether or not a starting operation has been performed. The CPU determines that a starting operation has been performed if the pedal depression depth AD exceeds a predetermined value ADth1(X%). If the CPU determines that a starting operation has been performed (102:Yes), it proceeds to step 103. On the other hand, if the CPU does not determine that a starting operation has been performed (102:No), it proceeds to step 105, and in step 105, it terminates the execution of program PR1.

[0047] In step 103, the CPU sets the flag Fs to "1" (a value indicating that the launch operation has been performed). The CPU then proceeds to step 104.

[0048] In step 104, the CPU sets the target value αt of the vehicle's acceleration α to a predetermined value αacc. That is, the CPU controls the drive system and other components so that the vehicle starts moving. Next, the CPU proceeds to step 105, in which step 105, the execution of program PR1 is terminated.

[0049] (Program PR2) The CPU starts executing Program PR2 from step 200 and proceeds to step 201.

[0050] In step 201, the CPU determines whether the driver is requesting acceleration of the vehicle. The CPU determines that the driver is requesting acceleration of the vehicle (an acceleration acceleration operation is being performed) if the pedal depression depth AD exceeds a predetermined value ADth2(Y%). If the CPU determines that an acceleration acceleration operation is being performed (201:Yes), it proceeds to step 202. On the other hand, if the CPU does not determine that an acceleration acceleration operation is being performed (201:No), it proceeds to step 204, and in step 204, it terminates the execution of program PR2.

[0051] In step 202, the CPU sets the target value αt of acceleration α to a predetermined value αover. Then, the CPU proceeds to step 203.

[0052] In step 203, the CPU sets the flag Fdis to "1" (a value indicating that the execution of acceleration suppression control is prohibited). Next, the CPU proceeds to step 204, in which step 204, terminates the execution of program PR2.

[0053] (Program PR3) The CPU starts executing Program PR3 from step 300 and proceeds to step 301.

[0054] In step 301, the CPU determines whether the vehicle has started moving. The CPU determines that the vehicle has started moving if flag Fs is "1". If the CPU determines that the vehicle has started moving (301: Yes), it proceeds to step 302. On the other hand, if the CPU does not determine that the vehicle has started moving (301: No), it proceeds to step 304, and in step 304, it terminates the execution of program PR3.

[0055] In step 302, the CPU determines whether or not the accelerator pedal AP has been released. The CPU determines that the release operation has been performed if the depression depth AD is less than or equal to a predetermined value ADth3(Z%). If the CPU determines that the release operation has been performed (302:Yes), it proceeds to step 303. On the other hand, if the CPU does not determine that the release operation has been performed (302:No), it proceeds to step 304, and in step 304, it terminates the execution of program PR3.

[0056] In step 303, the CPU sets the flag Frel to "1" (a value indicating that a return operation has been performed). Next, the CPU proceeds to step 304, in which step 304, the execution of program PR3 is terminated.

[0057] (Program PR4) The CPU starts executing Program PR4 from step 400 and proceeds to step 401.

[0058] In step 401, the CPU determines whether or not acceleration suppression control is permitted. The CPU determines that acceleration suppression control is permitted if the flag Fdis is "0". If the CPU determines that acceleration suppression control is permitted (401: Yes), it proceeds to step 402. On the other hand, if the CPU does not determine that acceleration suppression control is permitted (401: No), it proceeds to step 405, which will be described later.

[0059] In step 402, the CPU determines whether the driver has already performed the return operation. The CPU determines that the driver has already performed the return operation if the flag Frel is "1". If the CPU determines that the driver has already performed the return operation (402: Yes), it proceeds to step 403. On the other hand, if the CPU does not determine that the driver has already performed the return operation (402: No), it proceeds to step 405.

[0060] In step 403, the CPU determines whether the driver has requested acceleration suppression control to be performed. The CPU determines that the driver has requested acceleration suppression control (acceleration suppression operation is being performed) if point P[ΔAD,AD] in the Cartesian coordinate system shown in Figure 2(D) is included in the range R. If the CPU determines that acceleration suppression operation is being performed (403:Yes), it proceeds to step 404. On the other hand, if the CPU does not determine that acceleration suppression operation is being performed (403:No), it proceeds to step 405.

[0061] In step 404, the CPU sets the target value αt of acceleration α to a predetermined value αsup (<αacc). Next, the CPU proceeds to step 407, in which step 407, it terminates the execution of program PR4.

[0062] In step 405, the CPU determines whether the foot-in depth AD is less than or equal to a predetermined value ADth2. If the CPU determines that the foot-in depth AD is less than or equal to the predetermined value ADth2 (405: Yes), it proceeds to step 406. On the other hand, if the CPU does not determine that the foot-in depth AD is less than or equal to the predetermined value ADth2 (405: No), it proceeds to step 407, where it terminates the execution of program PR4. In this case, override control is performed by the execution of program PR2.

[0063] In step 406, the CPU sets the target value αt of acceleration α to a predetermined value αacc. Next, the CPU proceeds to step 407, in which step 407, it terminates the execution of program PR4.

[0064] (Effect) When a starting operation is performed while the vehicle is stopped, the driver assistance device 1 performs a starting control and automatically starts the vehicle. In other words, the driver operation to start the vehicle is assisted. If the driver feels that the acceleration of the vehicle due to the starting control is too rapid, the driver can suppress the acceleration of the vehicle by operating the accelerator pedal AP in a predetermined manner (performing an acceleration suppression operation).

[0065] (Modification 1) In the above embodiment, the ECU 10 determines that a starting operation has been performed when the depression depth AD of the accelerator pedal AP increases and exceeds "X%". Alternatively, the ECU 10 may determine that a starting operation has been performed when a predetermined resume switch 27 is pressed. In this example, the ECU 10 performs acceleration suppression control if condition A is met after the starting operation has been performed.

[0066] (Modified Example 2) In the above embodiment, the value assigned to the target value αt of acceleration α in acceleration suppression control is predetermined, but the driver may change the value assigned to the target value αt.

[0067] (Modification 3) In acceleration suppression control, the ECU 10 may continue acceleration suppression control if the accelerator pedal AP is released after the time during which the acceleration suppression operation has been performed exceeds a threshold (e.g., 3 seconds).

[0068] (Modification 4) The present invention may also be applied to a scenario in which the vehicle starts moving from a state in which it is stopped alone (or at the front of a convoy) (a state in which there is no preceding vehicle V1). That is, the ECU 10 may be configured to start the vehicle when a start operation is performed when there are no obstacles in front of it, and then suppress the acceleration of the vehicle when an operation is performed to suppress the acceleration (reduce the acceleration) during the period when the vehicle is accelerating. [Explanation of Symbols]

[0069] 1…Driving assistance system, 10…ECU, 20…On-board sensor, 30…Drive system, 40…Braking system

Claims

1. A driver assistance device comprising a processor configured to perform cruise control, which controls the vehicle to follow a preceding vehicle; to perform stop control, which stops the vehicle when predetermined stopping conditions are met while the cruise control is being performed; and to perform start control, which starts the vehicle by controlling the vehicle so that its acceleration matches a first predetermined value when a predetermined start operation is subsequently performed, wherein the processor is configured to perform cruise control, which controls the vehicle to start the vehicle, which follows a predetermined value, The driver assistance device is configured such that, after executing the starting control, the processor detects that a predetermined first accelerator pedal operation indicating the suppression of the vehicle's acceleration has been performed, and then executes acceleration suppression control to control the vehicle so that the vehicle's acceleration matches a second predetermined value which is smaller than the first predetermined value.

2. In the driving support device according to claim 1, The aforementioned processor, When the vehicle is stationary and the depth of the accelerator pedal is pressed increases to exceed a first predetermined value, the start control is executed. After the start control is performed, if the accelerator pedal depression depth decreases to below a second predetermined value, and then the system detects that the first accelerator pedal operation has been performed, the system will execute the acceleration suppression control. A driver assistance system configured in such a way.

3. In the driving support device according to claim 1, The aforementioned processor is configured to execute the start control when a predetermined switch is operated while the vehicle is stationary, and then to execute the acceleration suppression control when it detects that the first accelerator pedal has been operated.

4. In the driving support device according to claim 1, The processor is configured to perform override control to control the vehicle so that the acceleration of the vehicle matches a third predetermined value greater than the first predetermined value when a predetermined second accelerator pedal operation is performed that indicates the acceleration of the vehicle that has started moving by the start control is promoted, and when override control is performed, the execution of the acceleration suppression control is prohibited.

5. In the driving support device according to any one of claims 1 to 4, The aforementioned processor is a driver assistance device configured to determine that the first accelerator pedal operation has been performed when predetermined conditions for determining that the accelerator pedal is lightly pressed, specifically predetermined conditions relating to the depth of the accelerator pedal depression and its rate of change, are met.

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