Vehicle control device and vehicle control method

Abstract

To provide a vehicle control device that can reduce the frequency of a shortage of the deceleration amount due to automatic braking.SOLUTION: A vehicle control device calculates, based on a predetermined trajectory calculation lateral acceleration, a steering start threshold time that is "the time required for a self vehicle to collide with a target" at the time when a driver needs to start steering in order to avoid a collision between the self vehicle and the target, and starts automatic braking when the predicted collision time required for the self vehicle to collide with the target becomes equal to or less than the shorter of the steering start threshold time and an automatic braking start threshold time that is "the time required for the self vehicle to collide with the target" at the time when automatic braking needs to be started in order to avoid the collision. The vehicle control device calculates the steering start threshold time after setting the trajectory calculation lateral acceleration to a smaller value when the speed of the self vehicle is higher than a predetermined speed compared to when the speed of the self vehicle is lower than the predetermined speed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] One conventional device (hereinafter referred to as the "conventional device") that performs collision damage mitigation control determines, when it determines that there is a possibility of a collision between the vehicle and a target, a "steering limit collision time TTCc at which a collision can be avoided by the driver's steering" based on the lateral position of the target relative to the vehicle (e.g., the overlap ratio). If the steering limit collision time TTCc is greater than the braking limit collision time TTCy, the conventional device activates strong automatic braking when the collision prediction time TTC becomes equal to or less than the braking limit collision time TTCy. In contrast, if the steering limit collision time TTCc is shorter than the braking limit collision time TTCy, the conventional device activates strong automatic braking when the collision prediction time TTC becomes equal to or less than the steering limit collision time TTCc (see Patent Document 1). [Prior art documents] [Patent documents]

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

[0004] When the automatic brake is activated at the steering limit collision time TTCc, unnecessary activation of the automatic brake can be avoided if the driver is trying to avoid a collision by steering. However, if no steering is actually performed or if the actual steering amount is insufficient compared to the steering amount assumed to be necessary to avoid a collision, the host vehicle will collide with the target and the host vehicle will not be able to decelerate sufficiently before colliding with the target. In other words, in this case, the amount of deceleration by the automatic brake will be insufficient.

[0005] The present invention has been made to address such problems. That is, one of the objects of the present invention is to provide a vehicle control device and a vehicle control method that can avoid unnecessary operation of the automatic brake as much as possible and reduce the frequency of insufficient deceleration due to the automatic brake.

[0006] One aspect of the present invention is Acquire information about targets present around the vehicle; A time to collision (TTC) required for the host vehicle to collide with the target is obtained based on the information (S515); A steering start threshold time (TSRSth, TSLSth) is calculated based on a predetermined trajectory calculation lateral acceleration, which is the time required for the host vehicle to collide with the target at the point in time when the driver of the host vehicle needs to start steering to avoid collision between the host vehicle and the target (S530, S540). When the acquired collision prediction time (TTC) becomes equal to or less than the shorter of the steering start threshold time (TSRSth, TSLSth) and an automatic braking start threshold time (TBSth), which is the time required for the host vehicle to collide with the target at the time when automatic braking needs to be started to avoid the collision (see S550 to S560), the automatic braking is started (S565). The controller (10) is configured to:

[0007] After examining various data, the inventor has found that when the vehicle speed is high, the amount of steering and / or steering speed required by the driver to avoid a collision tends to be smaller than when the vehicle speed is low.

[0008] Therefore, the controller of the above aspect: The steering start threshold time is calculated using a smaller value as the trajectory calculation lateral acceleration 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 (see (A) and (B) of Figure 2).

[0009] According to this, when the vehicle speed (host vehicle speed) of the host vehicle is higher than a predetermined speed, the lateral acceleration for trajectory calculation decreases, and the calculated steering start threshold time increases. Therefore, the range of host vehicle speeds where the automatic braking start threshold time is shorter than the steering start threshold time expands to the higher speed side. As a result, automatic braking is initiated at the automatic braking start threshold time in a host vehicle speed range that is higher than conventionally. Therefore, the vehicle control device of the above aspect can narrow the vehicle speed range in which the deceleration amount due to automatic braking is insufficient while avoiding unnecessary operation of the automatic brake as much as possible, and can reduce 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 symbols used in the embodiments described below are enclosed in parentheses for the components of the invention corresponding to those embodiments. However, the components of the present invention are not limited to the embodiments defined by the names and / or symbols. The present invention also covers a vehicle control method and a program therefor. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic configuration diagram of a vehicle control device according to an embodiment of the present invention; [Figure 2] 10A and 10B are diagrams for explaining a steering start threshold time. [Figure 3] Graph showing the relationship between the relative speed of a stationary target and the amount of deceleration due to automatic braking. [Figure 4] Each of (A) to (C) is a lookup table that defines the relationship between the vehicle speed and the lateral acceleration for trajectory calculation. [Figure 5] A routine executed by the CPU of the vehicle control ECU shown in Figure 1. [Figure 6] 6 shows a routine executed by a CPU according to a modified example of the vehicle control ECU. DETAILED DESCRIPTION OF THE INVENTION

[0012] (composition) A vehicle control device DS (hereinafter referred to as "this control device") according to an embodiment of the present invention shown in Fig. 1 is mounted on a host vehicle. The host vehicle may be any of a vehicle powered by an internal combustion engine, a vehicle powered by an electric motor (i.e., an electric vehicle), a hybrid vehicle, etc.

[0013] This control device DS includes a vehicle control ECU 10, a powertrain ECU 30, and a brake ECU 40. These ECUs are connected to each other via a communication and sensor system CAN (Controller Area Network) to enable data exchange. ECU is an abbreviation for Electronic Control Unit, and is also called a controller or computer. The ECU is an electronic control circuit that has a microcomputer as its main component. The microcomputer includes a CPU (processor), ROM, RAM, and an interface. The CPU performs various functions, which will be described later, 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 are also capable of exchanging 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 speed of the host vehicle (i.e., host vehicle speed Vh), and receives an output signal from 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 will be simply referred to as "radar devices" when there is no need to distinguish between them.

[0016] The radar device is a well-known device that acquires information about targets present around the vehicle using millimeter-wave radio waves, and includes a "radar transceiver and processor (radar ECU)" (not shown). The radar transceiver transmits millimeter waves within a predetermined detection range every time a predetermined time elapses, and receives millimeter waves reflected by targets. The radar transceiver transmits information about the transmitted and received millimeter waves to the processor. The processor acquires radar target information based on the information from the radar transceiver and transmits the radar target information to the vehicle control ECU 10. The radar target information includes the distance between the position where the radar transceiver is located and the target, the azimuth of the target relative to the radar transceiver, and the relative speed of the target with respect to the radar transceiver.

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

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

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

[0020] The vehicle control ECU 10 integrates the radar target information transmitted from these radar devices to generate radar integrated target information for targets present around the host vehicle. The target information is expressed using an XY coordinate system. The X coordinate axis of this XY coordinate system extends in the longitudinal direction of the host vehicle and passes through the center of the host vehicle in the vehicle width direction. The Y coordinate axis of the XY coordinate system is an axis perpendicular to the X coordinate axis. The origin of the XY coordinate system is the center position of the front end of the host vehicle in the vehicle width direction. The radar integrated target information includes the distance (X coordinate value) between the host vehicle HV and the target, the orientation of the target relative to the host vehicle HV, and the relative speed of the target. In this example, the relative speed is a positive value when the target is approaching the host vehicle HV.

[0021] The forward camera device 23 includes a "camera and image ECU" (not shown). The camera captures an image of the scene ahead of the vehicle at predetermined intervals to acquire image data. Based on the image data from the camera, the image ECU recognizes (detects) the "left and right boundary lines" of the vehicle's own lane, the "left and right boundary lines" of the left adjacent lane adjacent to the left of the vehicle's own lane, and the "left and right boundary lines" of the right adjacent lane adjacent to the right of the vehicle's own lane. The right boundary line of the left adjacent lane is the left boundary line of the vehicle's own lane. The left boundary line of the right adjacent lane is the right boundary line of the vehicle's own lane. Note that lane boundaries are generally lane markings, such as white and yellow lines. The image ECU acquires the position and direction of the vehicle HV relative to the detected lane markings as marking line information. In addition, the image ECU generates camera target information based on the image data from the camera. The camera target information includes the "position (longitudinal and lateral positions) and type" of targets present ahead of the vehicle. The image ECU transmits the lane marking information and the camera target information to the vehicle control ECU 10.

[0022] The vehicle control ECU 10 integrates the radar integrated target information and the camera target information to generate fusion target information, which is final target information about targets present around the host vehicle.

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

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

[0025] (Overview of operation) In this specification, the time required for the host vehicle HV to collide with the target object PV if the host vehicle HV maintains its current vehicle speed and traveling direction is referred to as the "collision prediction time TTC."

[0026] As shown in Fig. 2A, when a target (in this example, a leading 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 the host vehicle HV may collide with the target PV. The target PV with which the host vehicle HV may collide is also called an "obstacle."

[0027] When the control device DS determines that there is a possibility that the host vehicle HV will collide with the target object PV, it calculates the time from the latest point at which the driver of the host vehicle HV needs to start steering to avoid the collision (hereinafter, sometimes referred to as the "steering start limit point") to the point at which the host vehicle HV would reach the target object PV if it were not steered. This time is called the "steering start threshold time." In other words, the "steering start threshold time" is the "predicted collision time at the steering start limit point." The steering start threshold time includes a steering start threshold time TSRSth for a right turn and a steering start threshold time TSLSth for a left turn.

[0028] More specifically, the control device DS calculates a trajectory CR, which is drawn by the left end point PL, which is obtained by moving the left front end of the host vehicle HV to the left by a margin distance α, assuming that the host vehicle HV is steered rightward. The trajectory CR is calculated based on a "predetermined trajectory-calculation lateral acceleration," which is the lateral acceleration of the host vehicle HV expected based on the driver steering rightward to avoid a collision. This trajectory CR is essentially a quadratic curve. The control device DS then translates the trajectory CR so that its starting point is located on the "line drawn by moving the left end point PL in the host vehicle HV's current traveling direction" and so that the trajectory CR passes through a position a predetermined distance away from the target object PV. Furthermore, the control device DS calculates a "steering start threshold time TSRSth for a right turn" by dividing the "distance between the starting point of this translated trajectory CR and the target object PV" by the "relative speed between the host vehicle HV and the target object PV."

[0029] Similarly, the control device DS calculates a "left-turn steering start threshold time TSLSth." That is, the control device DS calculates a trajectory CL that would be drawn by the right end point PR, which is obtained by moving the right front end of the host vehicle HV to the right by the margin distance α, assuming that the host vehicle HV is steered left. The trajectory CL is calculated based on a "predetermined trajectory-calculation lateral acceleration," which is the lateral acceleration of the host vehicle HV assumed based on the driver steering left to avoid a collision. This trajectory CL is essentially a quadratic curve. The control device DS then translates the trajectory CL so that its starting point is located on the "line drawn by moving the right end point PR in the host vehicle HV's current traveling direction" and so that the trajectory CL passes through a position a predetermined distance away from the target object PV. Furthermore, the control device DS calculates the "left-turn steering start threshold time TSLSth" by dividing the "distance between the starting point of this translated trajectory CL and the target object PV" by the "relative speed between the host vehicle HV and the target object PV."

[0030] When the collision prediction time TTC becomes equal to or shorter than a predetermined automatic braking initiation threshold time TBSth, if the collision prediction time TTC is shorter than both the "steering initiation threshold time for a right turn TSRSth and the steering initiation threshold time for a left turn TSLSth," the control device DS initiates automatic braking (see the case where TBSth = Ta in FIG. 2A). This allows the host vehicle HV to stop before colliding with the target object PV. Note that the automatic braking initiation threshold time TBSth is the limit time for initiating automatic braking (automatic emergency braking, AEB) to decelerate the host vehicle HV at a predetermined deceleration in order to stop the host vehicle HV immediately before it collides with the target object PV (the collision prediction time TTC at the latest point at which automatic braking should be initiated), and is calculated in advance and stored in the ROM of the vehicle control ECU 10.

[0031] In contrast, even if the collision prediction time TTC is equal to or less than the automatic braking start threshold time TBSth, if the collision prediction time TTC is longer than the shorter of the "steering start threshold time for right turns TSRSth and the steering start threshold time for left turns TSLSth", the control device DS will not start the automatic braking (see the case in Figure 2(A) 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 less than the shorter threshold time of "the steering start threshold time for a right turn TSRSth and the steering start threshold time for a left turn TSLSth."

[0033] This makes it possible to avoid a situation in which automatic braking is initiated before the driver has steered the vehicle to avoid a collision with a target object (a situation in which automatic braking is activated unnecessarily). On the other hand, because the initiation of automatic braking is delayed from the "point at which the collision prediction time TTC becomes equal to or shorter than the predetermined automatic braking initiation threshold time TBSth," the amount of deceleration (amount of change in speed) from the point at which automatic braking is initiated until the host vehicle HV reaches the target object PV is insufficient.

[0034] The dashed line in Figure 3 shows the relative speed of the stationary target and the deceleration amount due to the automatic brake when the above-mentioned predetermined trajectory calculation lateral acceleration is assumed to be a constant value a1 regardless of the host vehicle speed Vh, as shown in (A) of Figure 4. From the graph in Figure 3, it can be seen that the deceleration amount due to the automatic brake is sufficient until the relative speed of the stationary target reaches 3·A (km / h), but that the deceleration amount due to the automatic brake is insufficient once the relative speed of the stationary target exceeds 3·A (km / h).

[0035] Therefore, the present inventors have examined various data obtained when a driver avoids a collision by steering, and have found that when the host vehicle speed Vh is high, the steering amount or steering speed for collision avoidance tends to be smaller than when the host vehicle speed Vh is low (i.e., the driver tends not to steer so suddenly), and that when the host vehicle speed Vh is high, the lateral acceleration of the host vehicle HV when avoiding a collision by steering tends to be smaller than when the host vehicle speed Vh is low.

[0036] Based on this knowledge, the present control device DS is configured to calculate the trajectories CL and CR by using a value smaller than the trajectory calculation lateral acceleration when the host vehicle speed Vh is lower than the threshold speed as the trajectory calculation lateral acceleration when the host vehicle speed Vh is higher than a certain threshold speed (for example, 60 km / h or 80 km / h), as shown in (B) or (C) of Figure 4. Therefore, when the host 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 long, as shown in (B) of Figure 2.

[0037] As a result, as shown by the solid line in Fig. 3, the amount of deceleration by the automatic brake is sufficient until the host vehicle speed Vh (more precisely, the relative speed of the stationary target) reaches a larger value (4·A (km / h) in the example of Fig. 3). In other words, this control device DS is now able to avoid collisions by "automatic braking without unnecessary operation" up to a higher host vehicle speed range.

[0038] (Specific operation) The CPU of the vehicle control ECU 10 (hereinafter referred to as "CPU") executes the routine shown in the flowchart of FIG. 5 every time a predetermined time has elapsed. Note that "step" is denoted as "S" below. At a predetermined timing, the CPU starts processing from S500 in FIG. 5 and determines in S505 whether or not there is a target (i.e., an obstacle) with which there is a possibility of collision. More specifically, the CPU determines, based on the fusion target information, whether or not there is a target within the travel area (i.e., the host vehicle's predicted travel area PRA) of the host vehicle HV when the host vehicle HV travels for a predetermined time while maintaining the current travel direction and current host vehicle speed Vh.

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

[0040] If 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 predicted time to collision TTC by dividing the distance between the host vehicle and the obstacle by the relative speed of the obstacle. S520: The CPU reads the automatic brake start threshold time TBSth from the ROM. S525: The CPU calculates an automatic braking margin time TTCb by subtracting the automatic braking start threshold time TBSth from the collision prediction time TTC.

[0042] S530: The CPU obtains the lateral acceleration for trajectory calculation by applying the vehicle speed Vh to the lookup table shown in Figure 4 (B), and uses the lateral acceleration for trajectory calculation to calculate the steering start threshold time TSRSth for a right turn using the method described above.

[0043] According to the lookup table shown in Figure 4(B), when the host vehicle speed Vh is 60 km / h or less, the trajectory-calculation lateral acceleration is a constant value a1, when the host vehicle speed Vh is 80 km / h the trajectory-calculation lateral acceleration is a value a2 smaller than value a1, and when the host vehicle speed Vh is 100 km / h or more the trajectory-calculation lateral acceleration is a value a3 smaller than value a2. When the host vehicle speed Vh is between a "certain first vehicle speed" and a "certain second vehicle speed" in the lookup table, the trajectory-calculation lateral acceleration for that host vehicle speed Vh is determined by linear interpolation based on the "trajectory-calculation lateral acceleration corresponding to the first vehicle speed" and the "trajectory-calculation lateral acceleration corresponding to the second vehicle speed." Therefore, according to the lookup table shown in Figure 4 (B), when the vehicle speed Vh is higher than the predetermined speed of 60 km / h, the lateral acceleration for trajectory calculation is acquired as a smaller value than when the vehicle speed Vh is lower than the predetermined speed of 60 km / h.

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

[0045] S540: The CPU obtains the lateral acceleration for trajectory calculation by applying the vehicle speed Vh to the lookup table shown in Figure 4(B), and calculates the steering start threshold time TSLSth for a left turn using the lateral acceleration for trajectory calculation using the method described above.

[0046] S545: The CPU calculates a left-turn steering margin time TTCsL by subtracting a 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 equal to or less than the automatic braking start threshold time TBSth. That is, the CPU determines whether the automatic braking margin time TTCb is equal to or less than 0. If the collision prediction time TTC is equal to or 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 equal to or less than the right-turn steering start threshold time TSRSth. That is, the CPU determines whether the right-turn steering margin time TTCsR is equal to or less than 0. If the collision prediction time TTC is equal to or 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 equal to or less than the steering start threshold time TSLSth for a left turn. That is, the CPU determines whether the left turn steering margin time TTCsL is equal to or less than 0. If the collision prediction time TTC is equal to or less than the steering start threshold time TSLSth for a left turn, the CPU proceeds to S565.

[0050] The CPU initiates automatic braking in S565, and begins decelerating the host vehicle at a predetermined deceleration rate. As is clear from the above, automatic braking is initiated when the collision prediction time TTC becomes equal to or less than the smallest threshold time among the "automatic braking start threshold time TBSth, right-turn steering start threshold time TSRSth, and left-turn steering start threshold time TSLSth." Next, the CPU sets the value of the AEB execution flag XAEB to "1" in S570. Thereafter, the CPU proceeds to S595 and temporarily ends this routine.

[0051] If the CPU determines "No" in any of steps S505, S510, S550, S555, and S560, it proceeds directly from the step where it determined "No" to S595, where it temporarily ends this routine.

[0052] As explained above, the control device DS calculates the steering start threshold time by using a lateral acceleration for trajectory calculation when the host vehicle speed is higher than the predetermined speed that is smaller than the lateral acceleration for trajectory calculation when the host vehicle speed is lower than the predetermined speed. Therefore, when the host vehicle speed is higher than the predetermined speed, the steering start threshold time is longer, and the range of host vehicle speeds at which automatic braking is initiated when the "anticipated time to collision TTC" falls below the automatic braking start threshold time" is expanded to the higher speed side. As a result, the control device DS can narrow the vehicle speed range in which the amount of deceleration due to automatic braking is insufficient while avoiding unnecessary operation of the automatic brake as much as possible, thereby reducing the frequency of insufficient deceleration due to automatic braking.

[0053] The CPU may obtain the trajectory-calculation lateral acceleration using the lookup table shown in FIG. 4C instead of the lookup table shown in FIG. 4B, and use the trajectory-calculation lateral acceleration to calculate the "left-turn steering start threshold time TSLSth and right-turn steering start threshold time TSRSth" using the above-described method. The relationship between the trajectory-calculation lateral accelerations (values ​​b1 to b9) calculated using the lookup table shown in FIG. 4C is as shown in the inequality. Furthermore, the CPU may omit steps S525, S535, and S545 of FIG. 4. Additionally, instead of steps S550 to S560, the CPU may select the smallest threshold time from the "automatic braking start threshold time TBSth, right-turn steering start threshold time TSRSth, and 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 a routine in which part of the routine in FIG. 5 is replaced with part of the routine shown in FIG.

[0055] After completing the processing of S545 in Fig. 5, the CPU proceeds to S605 in Fig. 6. In S605, the CPU determines whether there is space on the left and right sides of the obstacle that the host vehicle HV can enter (i.e., pass through) based on the fusion target information, lane marking information, image data from the camera, etc. In other words, the CPU determines whether a collision with the obstacle can be avoided by turning the host vehicle HV left without colliding with a target other than the obstacle, and whether a collision with the obstacle can be avoided by turning the host vehicle HV right without colliding with a target other than the obstacle.

[0056] If the CPU determines "Yes" in S605, it executes the processes of S550 to S570 described with reference to FIG. 5, and then proceeds to S695 to temporarily end this routine.

[0057] In contrast, if the CPU determines "No" in S605, it proceeds to S610 and determines whether or not a collision with the obstacle can be avoided by turning the host vehicle HV left without causing a collision with an object other than the obstacle.

[0058] If the CPU determines "Yes" in S610, it makes the same determination in S615 as in S550, and if the CPU determines "Yes" in S615, it makes the same determination in S620 as in S560. If the CPU determines "Yes" in S620, it starts automatic braking in S625, sets the value of the AEB execution flag XAEB to "1" in S630, and proceeds to S695.

[0059] If the CPU judges "Yes" in S610, it may select the smaller threshold time between the automatic braking start threshold time TBSth and the steering start threshold time for left turns TSLSth, and if the collision prediction time TTC is less than or equal to the selected threshold time, it may perform the processing of S625 and S630.

[0060] If the CPU judges "No" in S610, it proceeds to S635 and determines whether a collision with the obstacle can be avoided by turning the host vehicle HV to the right without causing a collision with an object other than the obstacle.

[0061] If the CPU determines "Yes" in S635, it makes the same determination in S640 as in S550, and if the CPU determines "Yes" in S640, it makes the same determination in S645 as in S555. If the CPU determines "Yes" in S645, it starts automatic braking in S650, sets the value of the AEB execution flag XAEB to "1" in S655, and proceeds to S695.

[0062] If the CPU judges "Yes" in S635, it may select the smaller threshold time between the automatic braking start threshold time TBSth and the right turn steering start threshold time TSRSth, and if the collision prediction time TTC is less than or equal to the selected threshold time, it may perform the processing of S650 and S655.

[0063] If the CPU determines "No" in S635, it proceeds to S660 and makes the same determination as in S550. If the CPU determines "Yes" in S660, it 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, it proceeds directly to S695.

[0064] As explained above, the modified example of the control device DS initiates automatic braking after taking into consideration steering to avoid a collision in the direction where there is space for the host vehicle HV to enter. Therefore, unnecessary operation of the automatic brake can be avoided as much as possible, while narrowing the vehicle speed range in which the amount of deceleration due to the automatic brake is insufficient, and the frequency with which the amount of deceleration due to the automatic brake is insufficient can be reduced.

[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 a state where the driving mode has transitioned from autonomous driving to manual driving. [Explanation of symbols]

[0066] 10...vehicle control ECU, 21...front radar device, 22L...left front side radar device, 22R...right front side radar device, 23...front camera device, 24...vehicle speed sensor, 30...power train ECU, 40...brake ECU.

Claims

1. Acquire information about targets present around the vehicle; acquiring a predicted collision time required for the host vehicle to collide with the target based on the information; calculating a steering start threshold time, which is a time required for the host vehicle to collide with the target at a point in time when the driver of the host vehicle needs to start steering in order to avoid a collision between the host vehicle and the target, based on a predetermined trajectory-calculation lateral acceleration; When the acquired collision prediction time becomes equal to or less than the shorter of the steering start threshold time and an automatic braking start threshold time, which is the time required for the host vehicle to collide with the target at the time when it is necessary to start automatic braking to avoid the collision, the automatic braking is started. A controller configured as follows: In a vehicle control device comprising: The controller 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 host vehicle is higher than a predetermined speed than when the vehicle speed of the host vehicle is lower than the predetermined speed. Vehicle control device.

2. 2. The vehicle control device according to claim 1, The controller calculating both a right-turn steering start threshold time, which is the steering start threshold time when it is assumed that the host vehicle is steered to the right, and a left-turn steering start threshold time, which is the steering start threshold time when it is assumed that the host vehicle is steered to the left; When the acquired collision prediction time becomes equal to or less than the shortest threshold time among the steering start threshold time for turning right, the steering start threshold time for turning left, and the automatic braking start threshold time, the automatic braking is started. It was configured as follows: Vehicle control device.

3. 2. The vehicle control device according to claim 1, The controller If there is a right space into which the host vehicle can enter when the host vehicle is steered to the right to avoid the collision and there is no left space into which the host vehicle can enter when the host vehicle is steered to the left to avoid the collision, calculating a right-turn steering start threshold time, which is the steering start threshold time when it is assumed that the host vehicle is steered to the right; When the acquired collision prediction time becomes equal to or less than a shorter threshold time of the steering start threshold time for turning right and the automatic braking start threshold time, the automatic braking is started. It was configured as follows: Vehicle control device.

4. 2. The vehicle control device according to claim 1, The controller If there is a left space into which the host vehicle can enter when the host vehicle is steered left to avoid the collision and there is no right space into which the host vehicle can enter when the host vehicle is steered right to avoid the collision, calculating a steering start threshold time for turning left, which is the steering start threshold time when it is assumed that the host vehicle is steered to the left; When the acquired collision prediction time becomes equal to or less than a shorter threshold time of the steering start threshold time for turning left and the automatic braking start threshold time, the automatic braking is started. It was configured as follows: Vehicle control device.

5. acquiring information about targets present around the host vehicle; acquiring a predicted collision time required for the host vehicle to collide with the target based on the information; calculating a steering start threshold time, which is a time required for the host vehicle to collide with the target at a point in time when the driver of the host vehicle needs to start steering in order to avoid a collision between the host vehicle and the target, based on a predetermined trajectory-calculation lateral acceleration; starting the automatic braking when the acquired collision prediction time becomes equal to or less than a shorter threshold time of the steering start threshold time and an automatic braking start threshold time, which is the time required for the host vehicle to collide with the target at a point in time when it is necessary to start automatic braking to avoid the collision; A vehicle control method including: The step of calculating the steering start threshold time includes: a step of calculating the steering start threshold time after setting the trajectory-calculation lateral acceleration to a smaller value when the vehicle speed of the host vehicle is higher than a predetermined speed compared to when the vehicle speed of the host vehicle is lower than the predetermined speed. Vehicle control method.

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