Vehicle control device and vehicle control method

Abstract

A vehicle control device (DS) calculates, on the basis of a prescribed lateral acceleration for trajectory calculation, a steering start threshold time, which is the time required until the own vehicle collides with a target, at the time at which a driver needs to start steering in order to avoid a collision between the own vehicle and the target. When the predicted collision time required until the vehicle collides with the target is equal to or less than the shorter threshold time of the steering start threshold time and the automatic braking start threshold time, automatic braking is started. The automatic braking start threshold time is "the time required until the own vehicle collides with the target" at a timing at which automatic braking needs to be started in order to avoid the collision. The vehicle control device (DS) sets the lateral acceleration for trajectory calculation to a value that is smaller when the vehicle speed of the host vehicle is higher than a predetermined speed than when the vehicle speed of the host vehicle is lower than the predetermined speed, and calculates the steering start threshold time on the basis thereof.

Description

Technical Field

[0001] The present invention relates to a vehicle control device and a vehicle control method for executing collision damage reduction control using automatic braking. Background Art

[0002] One of the existing devices that performs collision damage mitigation control (hereinafter referred to as the "existing device"), when it is determined that there is a possibility of collision between the own vehicle and the target object, calculates the "steering limit collision time TTCc at which the collision can be avoided by the driver's steering" based on the lateral position of the target object relative to the own vehicle (for example, the overlap rate). When the steering limit collision time TTCc is greater than the braking limit collision time TTCy, the existing device causes a stronger automatic braking operation when the collision prediction time TTC becomes less than the braking limit collision time TTCy. In contrast, when the steering limit collision time TTCc is less than the braking limit collision time TTCy, the existing device causes a stronger automatic braking operation when the collision prediction time TTC becomes less than the steering limit collision time TTCc (see Patent Document 1). Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-114427 Summary of the Invention

[0004] Activating automatic braking within the steering limit collision time (TTCc) prevents unnecessary automatic braking when the driver attempts to avoid a collision through steering. However, if no steering is actually performed, or if the actual steering amount is insufficient for the steering amount assumed to avoid a collision, the vehicle may collide with the object, and the vehicle may not be sufficiently decelerated before the collision. In other words, in this case, the deceleration achieved by automatic braking is insufficient.

[0005] The present invention is made to solve this problem. Specifically, one of the objects of the present invention is to provide a vehicle control device and a vehicle control method that can minimize unnecessary automatic braking operations and reduce the frequency of insufficient deceleration due to automatic braking.

[0006] One embodiment of the present invention includes a controller (10) configured to: Acquire information about objects around the vehicle. Based on the information, a collision prediction time (TTC) required until the vehicle collides with the target object is obtained (S515). Calculating a steering start threshold time (TSRSth, TSLSth) based on a predetermined trajectory using lateral acceleration, wherein the steering start threshold time is the time required until the own vehicle collides with the target object at the moment when the driver of the own vehicle needs to start steering in order to avoid the collision between the own vehicle and the target object (S530, S540), When the obtained collision prediction time (TTC) becomes less than the shorter threshold time of the steering start threshold time (TSRSth, TSLSth) and the automatic braking start threshold time (TBSth) (refer to S550 to S560), automatic braking is started. The automatic braking start threshold time is the time required for the own vehicle to collide with the target object at the moment when the automatic braking needs to be started in order to avoid the collision (S565).

[0007] The inventors of the present invention studied various data and found that when the vehicle's own speed is high, the steering amount and / or steering speed that the driver uses to avoid a collision tends to be smaller than when the vehicle's own speed is low.

[0008] Therefore, the controller of the above scheme is configured as follows: The steering start threshold time is calculated by using a smaller value when the vehicle speed of the own vehicle is higher than the predetermined speed than when the vehicle speed of the own vehicle is lower than the predetermined speed as the trajectory calculation lateral acceleration. Figure 2 (A) and (B). ).

[0009] Thus, when the vehicle's own vehicle speed (own vehicle speed) exceeds the specified speed, the lateral acceleration used for trajectory calculation decreases, and therefore the calculated steering start threshold time increases. This expands the range of own vehicle speeds where the automatic braking start threshold time is shorter than the steering start threshold time toward higher speeds. As a result, automatic braking is initiated within the automatic braking start threshold time within a higher range of own vehicle speeds than before. Therefore, the vehicle control device of the above embodiment can minimize unnecessary automatic braking while narrowing the vehicle speed range where deceleration due to automatic braking is insufficient, thereby reducing the frequency of insufficient deceleration due to automatic braking.

[0010] In the above description, to facilitate understanding of the present invention, the names and / or reference numerals used in the embodiments described below are enclosed in parentheses regarding components of the invention corresponding to the embodiments described in those embodiments. However, the components of the present invention are not limited to the embodiments specified by these names and / or reference numerals. The present invention also relates to a vehicle control method and a program thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1It is a schematic configuration diagram of a vehicle control device according to an embodiment of the present invention. Figure 2 (A) and (B) are diagrams for explaining the steering start threshold time. Figure 3 Graph showing the relationship between the relative speed of a stationary object and the deceleration amount by automatic braking. Figure 4 (A) to (C) are lookup tables that define the relationship between the vehicle's own speed and the lateral acceleration used for trajectory calculation. Figure 5 is Figure 1 The routine shown is executed by the CPU of the vehicle control ECU. Figure 6 This is a routine executed by the CPU according to a modification of the vehicle control ECU. DETAILED DESCRIPTION

[0012] (constitute) Figure 1 The vehicle control device DS according to the embodiment of the present invention (hereinafter referred to as the "control device") is mounted on a vehicle. The vehicle may be a vehicle powered by an internal combustion engine, a vehicle powered by an electric motor (i.e., an electric vehicle), or a hybrid vehicle.

[0013] This control device DS includes a vehicle control ECU 10, a transmission system ECU 30, and a brake ECU 40. These ECUs are connected via a communication and sensor system CAN (Controller Area Network) so that they can exchange data. ECU is the abbreviation of Electronic Control Unit, also known as a controller or computer. ECU is an electronic control circuit with a microcomputer as its main component. The microcomputer includes a CPU (processor), ROM, RAM, and an interface. The CPU implements the various functions described below by executing instructions (routines) stored in the memory (ROM).

[0014] The control device DS includes a front radar device 21, a left front side radar device 22L, a right front side radar device 22R, and a front camera device 23. These devices can also exchange data with the vehicle control ECU 10 via the CAN. Furthermore, the vehicle control ECU 10 is connected to a vehicle speed sensor 24 that detects the vehicle's own speed (i.e., own vehicle speed Vh), and receives the output signal of the vehicle speed sensor 24.

[0015] The front radar device 21 , the left front side radar device 22L, and the right front side radar device 22R are all simply referred to as “radar devices” unless they need to be distinguished from each other.

[0016] The radar device is a well-known device that uses radio waves in the millimeter wave frequency band to obtain information related to target objects existing around its own vehicle, and includes a "radar transceiver and processing unit (radar ECU)" not shown in the figure. The radar transceiver sends millimeter waves to a specified detection range every specified time, and receives the millimeter waves reflected by the target object. The radar transceiver sends information related to the sent and received millimeter waves to the processing unit. The processing unit obtains radar target object information based on the information from the radar transceiver, and sends the radar target object information to the vehicle control ECU 10. The radar target object information includes the distance between the position where the radar transceiver is installed and the target object, the direction of the target object with respect to the radar transceiver, and the relative speed of the target object with respect to the radar transceiver.

[0017] The front radar device 21 is disposed at the front end of the vehicle and at the center in the vehicle width direction. The front radar device 21 acquires radar target information about a target existing in front of the vehicle and transmits the radar target information to the vehicle control ECU 10 .

[0018] The left front side radar device 22L is disposed at the front end and the left end in the vehicle width direction of the vehicle. The left front side radar device 22L acquires radar target information about a target located to the left front side of the vehicle and transmits the radar target information to the vehicle control ECU 10.

[0019] The right front side radar device 22R is disposed at the front end and right end of the vehicle in the vehicle width direction. The right front side radar device 22R acquires radar target information about a target located to the right front side of the vehicle and transmits the radar target information to the vehicle control ECU 10 .

[0020] The vehicle control ECU 10 integrates the radar target information sent from these radar devices to generate radar integrated target information related to the target objects present around the own vehicle. In addition, the target object information is represented using an XY coordinate system. The X-coordinate axis of the XY coordinate system is an axis extending in the front-rear axis direction of the own vehicle and passing through the center of the vehicle width direction of the own vehicle. The Y-coordinate axis of the XY coordinate system is an axis orthogonal to the X-coordinate axis. The origin of the XY coordinate system is the center position of the front end of the own vehicle in the vehicle width direction. The radar integrated target object information includes the distance (X-coordinate value) between the own vehicle HV and the target object, the direction of the target object relative to the own vehicle HV, and the relative speed of the target object. In this example, the relative speed is a positive value when the target object is approaching the own vehicle HV.

[0021] The front camera device 23 includes a camera and a graphics ECU (not shown). The camera captures the scene in front of the vehicle at predetermined intervals and acquires image data. Based on the image data from the camera, the graphics ECU identifies (detects) the left and right boundaries of the vehicle's lane, the left and right boundaries of the left adjacent lane to the left of the vehicle's lane, and the left and right boundaries of the right adjacent lane to the right of the vehicle's lane. The right boundary of the left adjacent lane is the left boundary of the vehicle's lane. The left boundary of the right adjacent lane is the right boundary of the vehicle's lane. Lane boundary lines are generally lane markers, such as white and yellow lines. The graphics ECU acquires the position and orientation of the vehicle HV relative to the detected lane markers as lane marker information. Furthermore, the graphics ECU generates camera target information based on the image data from the camera. This camera target information includes, for example, the position (longitudinal and lateral positions) and type of targets located in front of the vehicle. The graphic ECU transmits the dividing line information and the camera target information to the vehicle control ECU 10 .

[0022] The vehicle control ECU 10 integrates the radar integrated target object information and the camera target object information to generate final target object information on targets existing around the own vehicle, that is, fused target object information.

[0023] The powertrain ECU 30 receives detection signals from powertrain sensors 31, including an accelerator pedal operation amount sensor. The powertrain ECU 30 controls drive devices, including a power source (e.g., an internal combustion engine and / or an electric motor) of the vehicle (not shown), by driving a powertrain actuator 32, thereby adjusting the driving force of the vehicle.

[0024] The brake ECU 40 receives detection signals from brake sensors 41 including a brake pedal operation amount sensor, and controls a brake device (not shown) by driving a brake actuator 42, thereby adjusting the braking force applied to the vehicle.

[0025] (Operation Summary) In this specification, the time required until the own vehicle HV collides with the target object PV when the own vehicle HV maintains the current vehicle speed and traveling direction is referred to as "collision prediction time TTC".

[0026] like Figure 2As shown in (A), when a target object (in this example, a preceding vehicle) PV is present within the predicted travel area PRA of the host vehicle HV within a predetermined time, the control device DS determines that there is a possibility that the host vehicle HV will collide with the target object PV. The target object PV with which the host vehicle HV may collide is also referred to as an "obstacle."

[0027] When the control device DS determines that there is a possibility of a collision between the own vehicle HV and the target object PV, it calculates the time from the latest time at which the driver of the own vehicle HV needs to start steering to avoid the collision (hereinafter sometimes referred to as the "steering start threshold time") to the time when the own vehicle HV reaches the target object PV without being steered. This time is called the "steering start threshold time." In other words, the "steering start threshold time" is the "collision prediction time at the steering start threshold time." The steering start threshold time includes the steering start threshold time TSRSth for right turns and the steering start threshold time TSLSth for left turns.

[0028] More specifically, the control device DS calculates the trajectory CR, based on the lateral acceleration of the own vehicle HV assumed by the driver steering rightward to avoid a collision—the "predetermined trajectory calculation lateral acceleration." This trajectory CR is essentially a quadratic curve. The control device DS then parallelizes the trajectory CR so that its starting point is located on the line drawn by moving the left end point PL in the current direction of travel of the own vehicle HV and passes through a position a predetermined distance from the target object PV. Furthermore, the control device DS calculates the value of the distance between the starting point of the parallelized trajectory CR and the target object PV divided by the relative speed between the own vehicle HV and the target object PV, and uses this value as the "right turn steering start threshold time TSRSth."

[0029] Similarly, the control device DS calculates the "left turn steering start threshold time TSLSth." Specifically, based on the lateral acceleration of the own vehicle HV assumed by the driver steering left to avoid a collision, i.e., the "predetermined trajectory calculation lateral acceleration," the control device DS calculates the trajectory CL that would be drawn by the right end point PR, obtained by moving the right front end of the own vehicle HV rightward by a margin distance α, assuming the own vehicle HV is being steered left. This trajectory CL is essentially a quadratic curve. The control device DS then parallel-translates this trajectory CL so that its starting point lies on the line drawn by moving the right end point PR in the current direction of travel of the own vehicle HV and passes through a position a predetermined distance from the target object PV. Furthermore, the control device DS calculates the value of the distance between the starting point of the parallel-translated trajectory CL and the target object PV divided by the relative speed between the own vehicle HV and the target object PV, and uses this value as the "left turn steering start threshold time TSLSth."

[0030] When the collision prediction time TTC becomes less than the predetermined automatic braking start threshold time TBSth, if the collision prediction time TTC is shorter than either of the "steering start threshold time TSRSth for right turn and the steering start threshold time TSLSth for left turn", the control device DS starts automatic braking (at Figure 2 (A) of FIG. Refer to the case where TBSth = Ta. ). This allows the own vehicle HV to stop before colliding with the target object PV. Furthermore, the automatic braking start threshold time TBSth is the limit time (the latest time to start automatic braking, TTC) at which automatic braking (automatic emergency braking, AEB) should be initiated to decelerate the own vehicle HV at a predetermined deceleration in order to stop the own vehicle HV immediately before colliding with the target object PV. This threshold time is calculated in advance and stored in the ROM of the vehicle control ECU 10.

[0031] On the other hand, even when the collision prediction time TTC becomes less than the automatic braking start threshold time TBSth, the present control device DS does not start automatic braking if the collision prediction time TTC is longer than the shorter threshold time of "the steering start threshold time TSRSth for right turn and the steering start threshold time TSLSth for left turn". Figure 2 In (A), refer to the case where TBSth=Tb or Tc. ).

[0032] In this case, the control device DS starts automatic braking when the collision prediction time TTC becomes equal to or shorter than the shorter of the "right turn steering start threshold time TSRSth and left turn steering start threshold time TSLSth".

[0033] This can avoid situations where automatic braking is initiated first when the driver intends to avoid a collision with the object by steering (a situation where automatic braking is not necessarily performed). On the other hand, since automatic braking is initiated later than the time when the collision prediction time TTC becomes less than the predetermined automatic braking start threshold time TBSth, the deceleration amount (speed change) from the time when automatic braking is initiated to the time when the own vehicle HV reaches the object PV is insufficient.

[0034] Figure 3 The dotted line shows that Figure 4 As shown in (A), the relative speed of the stationary target object and the deceleration amount by automatic braking are calculated when the aforementioned predetermined trajectory calculation lateral acceleration is assumed to be a constant value a1 regardless of the own vehicle speed Vh. Figure 3 As can be understood from the graph, the deceleration amount based on automatic braking is sufficient until it reaches 3·A(km / h), but when the relative speed of the stationary target object exceeds 3·A(km / h), the deceleration amount based on automatic braking is insufficient.

[0035] Therefore, the present inventors studied various data obtained when a driver steers to avoid a collision. As a result, the present inventors discovered that when the own vehicle speed Vh is high, the steering amount or steering speed for collision avoidance is often smaller than when the own vehicle speed Vh is low (i.e., the driver does not steer as aggressively). Furthermore, when the own vehicle speed Vh is high, the lateral acceleration of the own vehicle HV when steering to avoid a collision is often smaller than when the own vehicle speed Vh is low.

[0036] Based on the above insights, the control device DS is configured as follows: Figure 4 As shown in (B) or (C), as the lateral acceleration for trajectory calculation when the own vehicle speed Vh is higher than a certain threshold speed (for example, 60 km / h or 80 km / h), a value smaller than the lateral acceleration for trajectory calculation when the own vehicle speed Vh is lower than the threshold speed is used, and on this basis, the trajectory CL and the trajectory CR are calculated, thereby calculating the steering start threshold time TSRSth for right turn and the steering start threshold time TSLSth for left turn. Therefore, as Figure 2 As shown in (B), when the vehicle speed Vh is higher than a certain threshold speed, the "steering start threshold time TSRSth for right turn and the steering start threshold time TSLSth for left turn" become longer.

[0037] The results, such as Figure 3 As shown by the solid line, the vehicle speed Vh (more precisely, the relative speed of the stationary object) reaches a larger value (at Figure 3In the example, the deceleration amount by automatic braking will not be insufficient until 4·A(km / h). That is, the control device DS can avoid a collision by "automatic braking without unnecessary operation" even in a higher vehicle speed range.

[0038] (Specific operation) The CPU of the vehicle control ECU 10 (hereinafter referred to as "CPU") executes the Figure 5 The routine shown in the flowchart in FIG. In addition, below, "step" is represented as "S". When the specified timing is reached, the CPU starts Figure 5 The process begins at S500, and in S505, it is determined whether there is a target object (i.e., obstacle) with which the vehicle may collide. More specifically, based on the fused target object information, the CPU determines whether there is a target object within the travel area (i.e., the predicted travel area PRA) of the vehicle HV when the vehicle HV maintains its current travel direction and current vehicle speed Vh for a predetermined time.

[0039] If an obstacle is present, the CPU proceeds from S505 to S510 to determine whether the value of the AEB (Automatic Emergency Braking) execution flag is "0." Furthermore, the value of the AEB execution flag XAEB is set to "0" by an ignition routine (not shown) executed by the CPU when a start switch (e.g., ignition key switch) (not shown) of the vehicle HV is turned from the OFF position to the ON position.

[0040] When the value of the AEB execution flag XAEB is “0”, the CPU sequentially performs the processes of “ S515 to S545 ” described below, and then proceeds to S550 .

[0041] S515: The CPU calculates the collision prediction time TTC by dividing the distance between the own vehicle and the obstacle by the relative speed of the obstacle. S520: The CPU reads the automatic braking start threshold time TBSth from the ROM. S525: The CPU calculates the automatic braking margin time TTCb by subtracting the automatic braking start threshold time TBSth from the collision prediction time TTC.

[0042] S530: The CPU applies the vehicle's own speed Vh to Figure 4 The trajectory calculation lateral acceleration is acquired by the lookup table shown in FIG. 1 (B), and the right turn steering start threshold time TSRSth is calculated by the above-mentioned method using the trajectory calculation lateral acceleration.

[0043] according to Figure 4According to the lookup table shown in (B), when the own vehicle speed Vh is below 60 km / h, the lateral acceleration for trajectory calculation is a constant value a1; when the own vehicle speed Vh is 80 km / h, the lateral acceleration for trajectory calculation is a value a2 which is smaller than a1; and when the own vehicle speed Vh is above 100 km / h, the lateral acceleration for trajectory calculation is a value a3 which is smaller than a2. In addition, when the own vehicle speed Vh is between "a certain first vehicle speed" and "a certain second vehicle speed" in the lookup table, the lateral acceleration for trajectory calculation for the own vehicle speed Vh is obtained by linear interpolation based on the "lateral acceleration for trajectory calculation corresponding to the first vehicle speed" and the "lateral acceleration for trajectory calculation corresponding to the second vehicle speed." Therefore, according to Figure 4 The lookup table shown in (B) obtains a smaller value as the trajectory calculation lateral acceleration when the vehicle speed Vh is higher than the predetermined speed of 60 km / h than when the vehicle speed Vh is lower than the predetermined speed of 60 km / h.

[0044] S535: The CPU calculates the right turn steering margin time TTCsR by subtracting the right turn steering start threshold time TSRSth from the collision prediction time TTC.

[0045] S540: The CPU applies the vehicle's own speed Vh to Figure 4 The trajectory calculation lateral acceleration is acquired by the lookup table shown in FIG. 1 (B), and the steering start threshold time TSLSth for a left turn is calculated by the above-mentioned method using the trajectory calculation lateral acceleration.

[0046] S545: The CPU calculates the left turn steering margin time TTCsL by subtracting the left turn steering start threshold time TSLSth from the collision prediction time TTC.

[0047] In S550 , the CPU determines whether the collision prediction time TTC is less than the automatic braking start threshold time TBSth. Specifically, the CPU determines whether the automatic braking margin time TTCb is less than "0." If the collision prediction time TTC is less than the automatic braking start threshold time TBSth, the CPU proceeds to S555 .

[0048] In S555, the CPU determines whether the collision prediction time TTC is less than the right turn steering start threshold time TSRSth. Specifically, the CPU determines whether the right turn steering margin time TTCsR is less than "0." If the collision prediction time TTC is less than the right turn steering start threshold time TSRSth, the CPU proceeds to S560.

[0049] In S560, the CPU determines whether the collision prediction time TTC is less than the left-turn steering start threshold time TSLSth. Specifically, the CPU determines whether the left-turn steering margin time TTCsL is less than "0." If the collision prediction time TTC is less than the left-turn steering start threshold time TSLSth, the CPU proceeds to S565.

[0050] In S565, the CPU initiates automatic braking, decelerating the vehicle at a preset deceleration rate. As can be seen above, automatic braking begins when the collision prediction time TTC becomes equal to or shorter than the minimum of the automatic braking start threshold time TBSth, the right turn steering start threshold time TSRSth, and the left turn steering start threshold time TSLSth. Next, in S570, the CPU sets the AEB execution flag XAEB to "1." The CPU then proceeds to S595, temporarily terminating this routine.

[0051] When the CPU makes a “No” determination in any of steps S505 , S510 , S550 , S555 , and S560 , the CPU directly proceeds to S595 from the step where the “No” determination is made, and temporarily terminates the present routine.

[0052] As described above, the present control device DS uses a lateral acceleration that is smaller than the lateral acceleration used for trajectory calculation when the vehicle's own speed is below a predetermined speed as the lateral acceleration used for trajectory calculation when the vehicle's own speed exceeds the predetermined speed, and calculates the steering start threshold time based on this. Consequently, when the vehicle's own speed exceeds the predetermined speed, the steering start threshold time becomes longer, thereby expanding the range of vehicle speeds within which automatic braking is initiated when the predicted time to collision (TTC) becomes less than the automatic braking start threshold time toward higher speeds. As a result, the present control device DS can minimize unnecessary automatic braking while narrowing the vehicle speed range within which the deceleration amount due to automatic braking is insufficient, thereby reducing the frequency of insufficient deceleration due to automatic braking.

[0053] In addition, the CPU can also replace Figure 4 The lookup table shown in (B) is used Figure 4 The lateral acceleration for trajectory calculation is obtained from the lookup table shown in (C), and the "steering start threshold time TSLSth for left turn and the steering start threshold time TSRSth for right turn" are calculated by the above method. Figure 4 The relationship between the lateral acceleration (value b1 to value b9) for trajectory calculation obtained from the lookup table shown in (C) is as shown in the inequality shown in the figure. Figure 5Alternatively, instead of performing steps S550 to S560, the CPU may select the smallest threshold time from "the automatic braking start threshold time TBSth, the right turn steering start threshold time TSRSth, and the left turn steering start threshold time TSLSth" as the determination threshold time, determine whether the collision prediction time TTC is equal to or less than the selected determination threshold time, and initiate automatic braking when the collision prediction time TTC is equal to or less than the selected determination threshold time.

[0054] (Variation) The CPU of the vehicle control ECU 10 according to the modified example of the control device DS executes Figure 5 Part of the routine is replaced by Figure 6 A routine that is a part of the routine shown.

[0055] CPU when finished Figure 5 After processing S545, proceed to Figure 6 S605. In S605, the CPU determines whether there is a space to the left and right of the obstacle that the host vehicle HV can enter (i.e., pass through) based on the fused target object information, the dividing line information, and the image data from the camera. In other words, the CPU determines whether the host vehicle HV can avoid colliding with objects other than the obstacle by turning left, and whether the host vehicle HV can avoid colliding with objects other than the obstacle by turning right.

[0056] When the CPU determines "Yes" in S605, the CPU executes the reference Figure 5 The processing of S550 to S570 described above proceeds to S695 and temporarily ends this routine. In addition, when the CPU determines "No" in any step of S550 to S560, it directly proceeds to step 695 from the step in which the determination is "No".

[0057] On the other hand, if the CPU makes a "No" determination in S605, the process proceeds to S610 to determine whether the host vehicle HV can avoid a collision with an obstacle by turning left without colliding with an object other than the obstacle.

[0058] If the CPU determines "yes" in S610, it performs the same determination as in S550 in S615. If it determines "yes" in S615, it performs the same determination as in S560 in S620. If it determines "yes" in S620, the CPU initiates automatic braking in S625, sets the value of the AEB execution flag XAEB to "1" in S630, and proceeds to S695. If the CPU determines "no" in either S615 or S620, it proceeds directly to step 695 from the step where the "no" determination was made.

[0059] Alternatively, when the CPU determines "yes" in S610, it may select the smaller of the automatic braking start threshold time TBSth and the steering start threshold time TSLSth for left turn, and perform S625 and S630 when the collision prediction time TTC is less than the selected threshold time.

[0060] When the CPU makes a "No" determination in S610, the process proceeds to S635 to determine whether or not the host vehicle HV can avoid a collision with an obstacle by turning right without colliding with an object other than the obstacle.

[0061] If the CPU determines "yes" in S635, it performs the same determination as in S550 in S640. If it determines "yes" in S640, it performs the same determination as in S555 in S645. If it determines "yes" in S645, the CPU starts automatic braking in S650, sets the value of the AEB execution flag XAEB to "1" in S655, and proceeds to S695. If the CPU determines "no" in either S640 or S645, it proceeds directly to step 695 from the step where the "no" determination was made.

[0062] Alternatively, when the CPU determines "yes" in S635, it may select the smaller of the automatic braking start threshold time TBSth and the steering start threshold time TSRSth for right turn, and perform S650 and S655 when the collision prediction time TTC is less than the selected threshold time.

[0063] If the CPU determines "No" in S635, the process proceeds to S660, where the same determination as in S550 is made. If the CPU determines "Yes" in S660, the process starts automatic braking in S665, sets the value of the AEB execution flag XAEB to "1" in S670, and then proceeds to S695. If the CPU determines "No" in S660, the process proceeds directly to S695.

[0064] As described above, the modified embodiment of the control device DS initiates automatic braking, taking into account steering toward a space where the own vehicle HV can enter in order to avoid a collision. This minimizes unnecessary automatic braking while narrowing the vehicle speed range where deceleration due to automatic braking is insufficient, thereby reducing the frequency of insufficient deceleration due to automatic braking.

[0065] The present invention is not limited to the above-described embodiment, and various modifications can be adopted within the scope of the present invention. For example, the present invention can be applied to an autonomous vehicle in which the driving mode is switched from autonomous driving to driver-driven driving. Reference numerals

[0066] 10…Vehicle control ECU; 21…Front radar unit; 22L…Left front side radar unit; 22R…Right front side radar unit; 23…Front camera unit; 24…Vehicle speed sensor; 30…Transmission system ECU; 40…Brake ECU.

Claims

1. A vehicle control device comprising a controller, wherein the controller is configured to: Acquire information about objects around the vehicle. Based on the information, a collision prediction time required until the own vehicle collides with the target object is obtained; A steering start threshold time is calculated based on a predetermined trajectory using lateral acceleration, wherein the steering start threshold time is the time required until the own vehicle collides with the target object at a point in time when the driver of the own vehicle needs to start steering in order to avoid a collision between the own vehicle and the target object. Automatic braking is initiated when the acquired collision prediction time becomes less than or equal to the shorter of the steering start threshold time and the automatic braking start threshold time, wherein the automatic braking start threshold time is the time required until the own vehicle collides with the target object at the moment when automatic braking needs to be initiated to avoid the collision. in, The controller is configured to: The steering start threshold time is calculated using, as the trajectory calculation lateral acceleration, a value that is smaller when the vehicle speed of the own vehicle is higher than a predetermined speed than when the vehicle speed of the own vehicle is lower than the predetermined speed.

2. The vehicle control device according to claim 1, wherein: The controller is configured to: calculating both a right turn steering start threshold time and a left turn steering start threshold time, wherein the right turn steering start threshold time is the steering start threshold time assuming that the vehicle is being steered to the right, and the left turn steering start threshold time is the steering start threshold time assuming that the vehicle is being steered to the left, The automatic braking is started when the acquired collision prediction time becomes equal to or shorter than the shortest threshold time among the right turn steering start threshold time, the left turn steering start threshold time, and the automatic braking start threshold time.

3. The vehicle control device according to claim 1, wherein: The controller is configured to: In the case where there is a right side space into which the own vehicle can enter when the own vehicle is steered right to avoid the collision, and there is no left side space into which the own vehicle can enter when the own vehicle is steered left to avoid the collision, The steering start threshold time for a right turn, that is, the steering start threshold time assuming that the own vehicle is steered to the right, is calculated; When the acquired collision prediction time becomes equal to or shorter than the shorter threshold time of the right turn steering start threshold time and the automatic braking start threshold time, the automatic braking is started.

4. The vehicle control device according to claim 1, wherein: The controller is configured to: In the case where there is a left side space into which the own vehicle can enter when the own vehicle is steered left to avoid the collision, and there is no right side space into which the own vehicle can enter when the own vehicle is steered right to avoid the collision, The steering start threshold time for a left turn, that is, the steering start threshold time assuming that the vehicle is steered to the left, is calculated; When the acquired collision prediction time becomes equal to or shorter than the shorter threshold time of the left-turn steering start threshold time and the automatic braking start threshold time, the automatic braking is started.

5. A vehicle control method, comprising: a step of acquiring information related to a target object existing around the own vehicle; a step of obtaining a collision prediction time required until the own vehicle collides with the target object based on the information; a step of calculating a steering start threshold time using lateral acceleration based on a predetermined trajectory, the steering start threshold time being a time required until the own vehicle collides with the target object at a point in time when the driver of the own vehicle needs to start steering in order to avoid a collision between the own vehicle and the target object; a step of starting automatic braking when the obtained collision prediction time becomes less than or equal to the shorter of the steering start threshold time and the automatic braking start threshold time, the automatic braking start threshold time being the time required until the own vehicle collides with the target object at the moment when the automatic braking needs to be started to avoid the collision; in, The step of calculating the steering start threshold time is as follows: The steering start threshold time is calculated based on the fact that the trajectory calculation lateral acceleration is set to a smaller value when the vehicle speed is higher than a predetermined speed than when the vehicle speed is lower than the predetermined speed.

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