Braking control method and braking control device

Abstract

To provide a braking control method and a braking control device which can control deceleration of an own vehicle in accordance with a moving direction of a moving object detected at a downstream side of a stop scheduled position.SOLUTION: A braking control device 100 controls a braking actuator 101 of an own vehicle 1 by a vehicle speed profile based on a vehicle speed Vc of the own vehicle 1, a position Pv of the own vehicle and a stop scheduled position Ps, using a processor 10. The processor 10 determines whether a detection device 102 of the own vehicle 1 has detected a moving object M in a predetermined area Xp at a downstream side of the stop scheduled position Ps; when determining that the detection device 102 has detected the moving object M, calculates an angle in the moving direction formed by a frontal direction Hv of the own vehicle 1 and a moving direction Hm of the moving object M, in the stop scheduled position Ps; and when the angle in the moving direction is equal to a first angle, generates the vehicle speed profile so that a deceleration relaxing position Pd becomes closer to an upstream side than when the angle in the moving direction is a second angle smaller than the first angle.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a braking control method and a braking control device. [Background technology]

[0002] The braking control device described in Patent Document 1 controls the braking operation of the host vehicle when a stopping object such as a pedestrian is detected ahead of the host vehicle, thereby slowing down the host vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-16248 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the braking control device of Patent Document 1 does not control the vehicle speed at a deceleration rate that corresponds to the direction in which a moving object such as a pedestrian is moving.

[0005] The problem to be solved by the present invention is to provide a braking control method and a braking control device that can control the deceleration of the vehicle in accordance with the direction of movement of a moving object detected downstream of the planned stopping position. [Means for solving the problem]

[0006] In the present invention, when a detection device detects a moving object downstream of a planned stop position, the detection device calculates a movement direction angle formed by a front direction of the vehicle at the planned stop position and a movement direction of the moving object, and when the movement direction angle is a first angle, a deceleration mitigation position when the vehicle decelerates upstream of the planned stop position is calculated. The larger The above problem is solved by generating a vehicle speed profile so that the vehicle speed is on the upstream side. [Effects of the Invention]

[0007] According to the present invention, the deceleration reduction position is set according to the movement direction angle, thereby achieving the effect of being able to control the deceleration of the vehicle according to the movement direction of a moving object detected downstream of the planned stopping position. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing a configuration of a braking control device according to an embodiment of the present invention; [Figure 2] 10A and 10B are diagrams illustrating an example of a movement direction angle formed between the front direction of the vehicle and the movement direction of a moving object. [Figure 3] 10A and 10B are diagrams illustrating an example of a movement direction angle formed between the front direction of the vehicle and the movement direction of a moving object. [Figure 4] 10A and 10B are diagrams illustrating an example of a movement direction angle formed between the front direction of the vehicle and the movement direction of a moving object. [Figure 5] 5A and 5B are diagrams showing examples of the positional relationship between the vehicle and a blind spot area, where FIG. 5A shows an example in which the blind spot area is located in front of the vehicle at the planned stopping position, and FIG. 5B shows an example in which the blind spot area is located in a direction different from the front of the vehicle at the planned stopping position. [Figure 6] 6A and 6B are diagrams showing examples of vehicle speed profiles generated by the braking control device shown in FIG. 1, where FIG. 6(a) is a graph showing the progression of deceleration in the vehicle speed profile, and FIG. 5(b) is a graph showing the progression of vehicle speed in the vehicle speed profile. [Figure 7] 2 is a graph showing an example of a virtual crossing time calculated by the braking control device shown in FIG. 1. [Figure 8] 2 is a flowchart showing the steps of a braking control method executed by the braking control device shown in FIG. [Figure 9] 10 is a graph showing another example of the deceleration of the vehicle speed controlled by the braking control device shown in FIG. [Figure 10] 10 is a graph showing another example of the deceleration of the vehicle speed controlled by the braking control device shown in FIG. [Figure 11] 10 is a graph showing another example of the deceleration of the vehicle speed controlled by the braking control device shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in Fig. 1, the host vehicle 1 has a braking control device 100, a braking actuator 101, and a detection device 102. The braking control device 100 autonomously controls the braking actuator 101. The braking control device 100 controls the braking operation of the host vehicle 1 by controlling the braking actuator 101. In this way, the braking control device 100 can start deceleration of the host vehicle 1 and control the deceleration of the host vehicle during deceleration.

[0010] The detection device 102 is, for example, an exterior camera or radar. The detection device 102 can detect the presence of a moving object. A moving object is a movable object, such as a pedestrian, a bicycle, a wheelchair, an animal, or another vehicle. The detection device 102 can also detect obstacles fixed in a predetermined position. Furthermore, the detection device 102 can detect lane boundaries, outer road lines, shoulder strips, and the like, marked on the road surface.

[0011] Next, the configuration of the braking control device 100 will be described in detail with reference to FIGS. As shown in Fig. 1, the braking control device 100 includes a processor 10 that controls a braking actuator 101 of the host vehicle 1. The processor 10 is composed of a ROM (Read Only Memory) that stores a program for controlling the driving of the host vehicle, a CPU (Central Processing Unit) that executes the program stored in the ROM, and a RAM (Random Access Memory) that functions as an accessible storage device. Note that, as the operating circuit, an MPU (Micro Processing Unit), a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), etc. can be used instead of or in addition to the CPU (Central Processing Unit). The processor 10 includes a driving state acquisition unit 11, a planned stop position acquisition unit 12, a moving object detection determination unit 13, a moving object predicted trajectory calculation unit 14, a vehicle predicted trajectory acquisition unit 15, an intersection determination unit 16, an intersection position calculation unit 17, a virtual intersection time calculation unit 18, a movement direction angle calculation unit 19, a blind spot area determination unit 20, a threshold time setting unit 21, a virtual intersection time determination unit 22, a vehicle speed profile generation unit 30, and a braking control unit 40. In FIG. 1, the braking control device 100 is mounted on the host vehicle 1, but the present invention is not limited to this, and the braking control device 100 may be a device that remotely controls the host vehicle 1.

[0012] The traveling state acquisition unit 11 of the braking control device 100 acquires the vehicle speed Vc and the vehicle position Pv of the host vehicle 1. The traveling state acquisition unit 11 acquires the vehicle speed Vc of the host vehicle 1 from a vehicle speed sensor (not shown) provided in the host vehicle 1. The traveling state acquisition unit 11 also detects radio waves transmitted from multiple satellite communications by a GPS unit, and periodically acquires position information of the host vehicle. The traveling state acquisition unit 11 also acquires the current and / or future vehicle position Pv based on the position information of the host vehicle acquired by the GPS unit, angle change information acquired from the gyro sensor, and the vehicle speed Vc acquired from the vehicle speed sensor.

[0013] The planned stop position acquisition unit 12 acquires a planned stop position Ps where the host vehicle 1 is scheduled to stop. For example, as shown in FIGS. 2 to 4, when the host vehicle 1 traveling on lane L1 turns left, crosses sidewalk L2, and enters a parking lot or the like, the planned stop position acquisition unit 12 acquires, as the planned stop position Ps, a position just upstream of the outer roadway line B detected by the detection device 102. Alternatively, the planned stop position acquisition unit 12 may acquire the planned stop position Ps based on road information acquired from a map database or by communication means.

[0014] The vehicle speed profile generating unit 30 generates a vehicle speed profile that defines the deceleration for the position (see FIGS. 2 to 4) on the path (host vehicle predicted trajectory Rv) of the host vehicle 1 to the predicted stop position Ps (see FIGS. 2 to 4) based on the host vehicle speed Vc and host vehicle position Pv of the host vehicle 1 acquired by the traveling state acquiring unit 11 and the predicted stop position Ps acquired by the predicted stop position acquiring unit 12. The vehicle speed profile is defined by the position of the host vehicle 1 up to the predicted stop position Ps and the deceleration of the host vehicle 1. FIG. 6(a) shows an example of a vehicle speed profile defined by the transition of the deceleration of the host vehicle 1 with respect to the distance (positional relationship) between the host vehicle position Pv and the predicted stop position Ps. The distance between the host vehicle position Pv and the predicted stop position Ps is the travel distance when the host vehicle 1 travels along the predicted host vehicle trajectory Rv. FIG. 6(b) shows the transition of the host vehicle speed Vc of the host vehicle 1 corresponding to the graph of FIG. 6(a). The vertical axis of FIG. 6(a) represents the deceleration of the host vehicle 1. The vertical axis in Fig. 6(b) represents the vehicle speed Vc of the host vehicle 1. The horizontal axis in Figs. 6(a) and 6(b) represents the distance of the host vehicle position Pv from the planned stop position Ps. The dashed line graph represents an example of a first vehicle speed profile Q1 that is used when the virtual intersection time determination unit 22 (described later) determines that there is no need to change the vehicle speed profile. The solid line graph represents an example of a second vehicle speed profile Q2 (changed vehicle speed profile) that is used when the virtual intersection time determination unit 22 (described later) determines that there is a need to change the vehicle speed profile. The procedure for changing the vehicle speed profile will be described later.

[0015] The vehicle speed profile is made up of a plurality of data items that the brake control device 100 uses to control the vehicle speed of the host vehicle 1. Specifically, as shown in the dashed and solid line graphs in FIG. 6 , the vehicle speed profile has a deceleration start position Pb (Pb0, Pb1) upstream of the expected stop position Ps. The deceleration start position Pb is the position where the host vehicle 1 starts to decelerate. The section between the deceleration start position Pb and the expected stop position Ps is a braking section Db (Db0, Db1) where the brake control device 100 controls the deceleration of the host vehicle 1. The vehicle speed profile also has a reference deceleration reach position Pa located upstream of the expected stop position Ps and downstream of the deceleration start position Pb, and a deceleration mitigation position Pd located downstream of the reference deceleration reach position Pa and upstream of the expected stop position Ps. In other words, the deceleration mitigation position Pd is located downstream of the deceleration start position Pb and upstream of the expected stop position Ps.

[0016] The section between the reference deceleration reach position Pa and the deceleration relaxation position Pd is a reference deceleration section Dc (Dc0, Dc1) in which the reference deceleration dV0 is maintained. That is, the host vehicle 1 travels at the reference deceleration dV0 in the reference deceleration section Dc. Furthermore, the section between the deceleration relaxation position Pd (Pd0, Pd1) and the expected stop position Ps is a deceleration reduction section Dd (Dd0, Dd1) in which braking control is performed at a deceleration lower than the reference deceleration dV0 in the deceleration reduction section Dd. That is, the host vehicle 1 travels at a deceleration lower than the reference deceleration dV0 in the deceleration reduction section Dd. Furthermore, the deceleration relaxation position Pd is the start position of the deceleration reduction section Dd. The deceleration of the host vehicle 1 based on the vehicle speed profile is a predetermined reference deceleration dV0 in the reference deceleration section Dc, and is lower than the reference deceleration dV0 in the deceleration reduction section Dd.

[0017] More specifically, the deceleration of the host vehicle 1 based on the vehicle speed profile generated by the vehicle speed profile generating unit 30 increases from the deceleration start position Pb to the reference deceleration reach position Pa, and reaches the reference deceleration dV0 at the reference deceleration reach position Pa. Next, the deceleration dV of the host vehicle 1 maintains a constant reference deceleration dV0 from the reference deceleration reach position Pa to the deceleration relaxation position Pd (reference deceleration section Dc). Note that the deceleration change rate is 0 (zero) in the reference deceleration section Dc. Next, the deceleration dV of the host vehicle 1 decreases at a constant deceleration change rate from the deceleration relaxation position Pd (start position of the deceleration reduction section Dd) to the expected stop position Ps (deceleration reduction section Dd). Then, the deceleration dV of the host vehicle 1 becomes 0 (zero) at the expected stop position Ps. That is, the vehicle speed profile is a profile in which the host vehicle 1 starts deceleration at a deceleration start position Pb upstream of the planned stop position Ps, travels through a predetermined section (reference deceleration section Dc) at a predetermined reference deceleration dV0, and then the deceleration of the host vehicle 1 decreases below the reference deceleration dV0 at a deceleration relaxation position Pd downstream of the deceleration start position Pb and upstream of the planned stop position Ps. Also, the deceleration relaxation position Pd1 in the second vehicle speed profile Q2 (solid line graph) shown in Figure 6(a) is located upstream of the deceleration relaxation position Pd0 in the first vehicle speed profile Q1 (dashed line graph).

[0018] 1 determines whether the detection device 102 has detected a moving object M in a predetermined area Xp (see FIGS. 2 to 5) downstream of the planned stop position Ps, based on the detection result of the detection device 102. The predetermined area Xp is a range in which any moving object that may intersect with the host vehicle 1 may exist.

[0019] 2 to 4, the moving object predicted trajectory calculation unit 14 calculates a moving object predicted trajectory Rm of the moving object M based on the position, moving direction Hm, and moving speed of the moving object M. Specifically, the moving object predicted trajectory calculation unit 14 calculates the moving object predicted trajectory Rm by assuming that the moving object M moves linearly from its current position along the moving direction Hm while maintaining its current moving speed. Note that, when a pedestrian, which is the moving object M, is moving along a sidewalk L2 as shown in FIGS. 2 and 3, the moving object predicted trajectory calculation unit 14 may calculate a moving object predicted trajectory Rm along the extension direction of the sidewalk L2.

[0020] The host vehicle predicted trajectory acquisition unit 15 acquires a host vehicle predicted trajectory Rv, which is a route along which the host vehicle 1 is predicted to travel. The host vehicle predicted trajectory Rv is a trajectory that is set based on the location information of the destination, the set route information, lane information, etc. Furthermore, for example, if the driver inputs to an in-vehicle input device (not shown) that the host vehicle 1 will stop at a store or the like before reaching the destination, the host vehicle predicted trajectory acquisition unit 15 acquires the host vehicle predicted trajectory Rv so that the host vehicle 1 traveling in the lane L1 will turn left and cross the sidewalk L2, as shown in FIGS. 2 to 4.

[0021] The intersection determination unit 16 determines whether the host vehicle predicted trajectory Rv and the moving object predicted trajectory Rm will intersect. In other words, the intersection determination unit 16 determines whether there is a possibility that the host vehicle 1 and the moving object M will intersect, assuming that the host vehicle 1 travels along the host vehicle predicted trajectory Rv without stopping at the planned stop position Ps and the moving object M moves along the moving object predicted trajectory Rm without changing the movement speed and movement direction Hm.

[0022] 2 to 4, the intersection position calculation unit 17 calculates an intersection position Px between the host vehicle predicted trajectory Rv and the moving object predicted trajectory Rm. Note that the intersection position Px is not limited to the point where the host vehicle predicted trajectory Rv and the moving object predicted trajectory Rm intersect, and the intersection position Px may be calculated as a position where the moving object M is predicted to enter a band-like area of ​​a predetermined width that includes the host vehicle predicted trajectory Rv.

[0023] Based on the vehicle speed profile generated by the vehicle speed profile generating unit 30, the virtual intersection time calculating unit 18 calculates a virtual intersection time Tk by dividing a virtual intersection distance Dx, which is a virtual traveling distance between a plurality of virtual positions Pk upstream of the intended stop position Ps and the intersection position Px, by a virtual vehicle speed Vk corresponding to each virtual position Pk, as shown in Fig. 2. In other words, the virtual intersection time Tk is the time it takes for the virtual subject vehicle 1' to reach the intersection position Px from the virtual position Pk, assuming that the virtual subject vehicle 1' is traveling at the virtual vehicle speed Vk according to the vehicle speed profile at the virtual position Pk, and that the virtual subject vehicle 1' continues to travel at the virtual vehicle speed Vk after passing the virtual position Pk. That is, the virtual intersection time Tk is calculated by the following equation (1).

number

[0024] A graph showing the relationship between the virtual intersection time Tk calculated by the virtual intersection time calculation unit 18 and the virtual intersection distance Dx is shown in Fig. 7. The vertical axis of Fig. 7 represents the virtual intersection time Tk. That is, Fig. 7 is a graph showing the virtual intersection times Tk calculated for a plurality of virtual positions Pk obtained consecutively between the deceleration start position Pb and the expected stop position Ps.

[0025] 1 calculates, as shown in FIGS. 2 to 4, movement direction angles A1, A2, and A3 formed between the front direction Hv of the host vehicle 1 at the expected stop position Ps and the movement direction Hm of the moving object M. In the example shown in FIG. 2, the moving object M is moving in the same direction as the traveling direction of the host vehicle 1 (to the right in the drawing), and the movement direction angle A1 formed between the front direction Hv of the host vehicle 1 and the movement direction Hm of the moving object M at the expected stop position Ps is an acute angle. In the example shown in FIG. 3, the moving object M is moving in the opposite direction to the traveling direction of the host vehicle 1 (to the left in the drawing), and the movement direction angle A2 formed between the front direction Hv of the host vehicle 1 at the expected stop position Ps and the movement direction Hm of the moving object M is an obtuse angle. Furthermore, in the example shown in Figure 4, the moving object M is moving in a direction opposite to the vehicle 1 at the planned stopping position Ps, and the movement direction angle A3 formed by the forward direction Hv of the vehicle 1 at the planned stopping position Ps and the movement direction Hm of the moving object M is an obtuse angle.

[0026] Furthermore, when the moving object detection determination unit 13 determines that a moving object M has not been detected in the predetermined area Xp (when the detection device 102 does not detect a moving object M in the predetermined area Xp), the blind spot area determination unit 20 determines whether or not a blind spot area Xb exists in the predetermined area Xp, as shown in FIG. 5, based on the detection result of the detection device 102. Furthermore, when the blind spot area determination unit 20 determines that a blind spot area Xb exists in the predetermined area Xp, it determines whether or not the blind spot area Xb is located in the front direction Hv of the host vehicle 1 at the planned stop position Ps. Specifically, in the example shown in FIG. 5(a), the blind spot area Xb is located in the front direction Hv of the host vehicle 1 at the planned stop position Ps. On the other hand, in the example shown in FIG. 5(b), the blind spot area Xb is not located in the front direction Hv of the host vehicle 1 at the planned stop position Ps.

[0027] As shown in FIG. 7, the threshold time setting unit 21 shown in FIG. 1 sets threshold times Tx (Tx0, Tx1) of the virtual intersection time Tk for determining whether or not a change in the vehicle speed profile is required. The threshold time setting unit 21 sets the threshold time Tx1 when the moving direction angle calculated by the moving direction angle calculation unit 19 is a first angle to be longer than the threshold time Tx0 when the moving direction angle is a second angle smaller than the first angle. Specifically, as shown in FIG. 2, the threshold time setting unit 21 sets the threshold time Tx0 when the moving direction angle A1 is an acute angle (less than 90 degrees). Furthermore, as shown in FIGS. 3 and 4, the threshold time setting unit 21 sets the threshold time Tx1 when the moving direction angles A2 and A3 are right angles or obtuse angles (90 degrees or greater). Note that the threshold time setting unit 21 may set the threshold time Tx to be longer as the moving direction angle increases, regardless of whether the moving direction angle is 90 degrees or greater. That is, the threshold time setting unit 21 may set the threshold time Tx to gradually increase depending on the magnitude of the movement direction angle, based on the threshold time Tx0 when no moving object M is detected in the specified area Xp and the blind spot area Xb described later does not exist in the specified area Xp.

[0028] Furthermore, when a moving object M is not detected in the predetermined area Xp, the threshold time setting unit 21 sets the threshold time Tx when the blind spot area determination unit 20 determines that a blind spot area Xd exists to be longer than the threshold time Tx when the blind spot area determination unit 20 determines that a blind spot area Xb does not exist. Furthermore, when the threshold time setting unit 21 determines that a blind spot area Xb exists, it sets the threshold time Tx when the blind spot area Xb is located in the front direction Hv of the vehicle 1 at the expected stop position Ps as shown in Figure 5(a) to be longer than the threshold time Tx when the blind spot area Xb is not located in the front direction Hv as shown in Figure 5(b).

[0029] Furthermore, the threshold time setting unit 21 may set the threshold time Tx based on at least one of the size, shape, and behavior of the moving object M. For example, if the height of the pedestrian, who is the moving object M, detected by the detection device 102 is equal to or less than a predetermined value, the threshold time setting unit 21 determines that the moving object M is a child, and sets the value of the threshold time Tx to be larger than that when the moving object M is an adult pedestrian. Furthermore, if the threshold time setting unit 21 determines that the pedestrian, who is the moving object M, detected by the detection device 102 is behaving with larger movements than a normal adult pedestrian, the threshold time setting unit 21 determines that the moving object M is a child, and sets the value of the threshold time Tx to be larger than that when the moving object M is an adult pedestrian. Furthermore, the threshold time setting unit 21 may set the threshold time Tx by determining the attributes of the moving object M (whether adult or child, human or animal, pedestrian or bicycle, etc.) according to the shape of the moving object M. In addition, the threshold time setting unit 21 may set the threshold time Tx based only on the presence or absence of a moving object in the specified area Xp and the magnitude of the movement direction angle, regardless of the presence or absence of a blind spot area Xd or the size, shape or behavior of the moving object M.

[0030] The virtual intersection time determination unit 22 determines whether at least one virtual intersection time Tk shown in FIG. 7 is equal to or shorter than the threshold time Tx. When the virtual intersection time determination unit 22 determines that at least one virtual intersection time Tk is equal to or shorter than the threshold time Tx, the virtual intersection time determination unit 22 outputs a command to the vehicle speed profile generation unit 30 to modify the vehicle speed profile so as to change the deceleration reduction position Pd to the upstream side. As a result, the first vehicle speed profile Q1 (dashed line) shown in FIG. 6 is changed to the second vehicle speed profile Q2 (solid line), and the deceleration reduction position Pd0 of the first vehicle speed profile Q1 is changed to the deceleration reduction position Pd1 of the second vehicle speed profile Q2. As a result, the graph of the virtual intersection time Tk shown in FIG. 7 is changed from the dashed line graph to the solid line graph.

[0031] More specifically, as shown in FIG. 7, when the threshold time Tx0 is set, all of the virtual intersection times Tk (dashed lines) corresponding to the first vehicle speed profile Q1 are greater than the threshold time Tx0, and the virtual intersection time determination unit 22 determines that there is no need to modify the vehicle speed profile. As a result, as shown in FIG. 6(a), the deceleration relaxation position Pd of the vehicle speed profile becomes the deceleration relaxation position Pd0 of the first vehicle speed profile Q1. On the other hand, as shown in FIG. 7, when the threshold time Tx1 is set, part of the virtual intersection time Tk (dashed lines) corresponding to the first vehicle speed profile Q1 is less than the threshold time Tx1, and the virtual intersection time determination unit 22 determines that there is a need to modify the vehicle speed profile. As a result, as shown in FIG. 6(a), the deceleration relaxation position Pd of the vehicle speed profile is corrected to the deceleration relaxation position Pd1 of the second vehicle speed profile Q2. In other words, the vehicle speed profile generation unit 30 generates a vehicle speed profile such that the deceleration relaxation position Pd of the vehicle speed profile is located more upstream as the threshold time Tx increases. Furthermore, by shifting the deceleration mitigation position Pd of the file to a more upstream position, the virtual intersection times Tk calculated by the virtual intersection time calculation unit 18 also increase, and as shown in the solid line graph in Figure 7, all of the virtual intersection times Tk become greater than the threshold times Tx (Tx0, Tx1).

[0032] That is, when the movement direction angle is a first angle (A2, A3), the deceleration relaxation position Pd is located further upstream than when the movement direction angle is a second angle (A1) smaller than the first angle. Furthermore, when a blind spot Xb exists in the predetermined area Xp, the deceleration relaxation position Pd is located further upstream than when a blind spot Xb does not exist in the predetermined area Xp. Furthermore, when it is determined that a blind spot Xb is located in the forward direction Hv of the host vehicle 1 at the expected stop position Ps, the deceleration relaxation position Pd is located further upstream than when it is determined that a blind spot Xb is not located in the forward direction Hv. Note that shifting the deceleration relaxation position Pd of the vehicle speed profile upstream is equivalent to advancing the deceleration relaxation timing for reducing the deceleration of the host vehicle 1 below the reference deceleration dV0.

[0033] Furthermore, when multiple blind spot areas Xb exist within the predetermined area Xp, the threshold time setting unit 21 sets a threshold time Tx for each of the multiple blind spot areas Xb, and the virtual intersection time determination unit 22 calculates a deceleration relaxation position Pd for each of the multiple blind spot areas Xb based on the respective threshold times Tx. The virtual intersection time determination unit 22 may then select the most upstream deceleration relaxation position Pd from the calculated multiple deceleration relaxation positions Pd and output a command to set a vehicle speed profile to the vehicle speed profile generation unit 30. That is, when multiple blind spot areas Xb exist within the predetermined area Xp and at least one blind spot area Xb is located in the forward direction Hv of the host vehicle 1 at the expected stop position Ps, the virtual intersection time determination unit 22 selects the deceleration relaxation position Pd (the most upstream deceleration relaxation position Pd) corresponding to the blind spot area Xb located in the forward direction Hv of the host vehicle 1 and outputs a command to correct the vehicle speed profile to the vehicle speed profile generation unit 30.

[0034] 1 controls the brake actuator 101 in accordance with the vehicle speed profile generated by the vehicle speed profile generating unit 30. As a result, the brake control unit 40 controls the vehicle speed Vc of the host vehicle 1 so that the host vehicle 1 decelerates in accordance with the deceleration defined in the vehicle speed profile. Note that the vehicle speed Vc and deceleration dV of the host vehicle 1 actually controlled based on the vehicle speed profile do not necessarily match the vehicle speed Vc and deceleration dV defined in the vehicle speed profile, but are values ​​affected by the driving environment of the host vehicle 1, road surface conditions, etc.

[0035] Next, the procedure of the braking control method executed by the processor 10 of the braking control device 100 will be described with reference to FIG. 8 This will be explained using the flowchart shown in FIG. In step S1 , the planned stop position acquisition unit 12 acquires the planned stop position Ps based on the detection result of the detection device 102 . Next, in step S2, the vehicle speed profile generating unit 30 generates a vehicle speed profile based on the vehicle speed Vc of the host vehicle 1, the host vehicle position Pv, ​​and the planned stop position Ps.

[0036] Next, in step S3, the moving object detection determination unit 13 acquires the position of the moving object M detected by the detection device 102, and determines whether the moving object M is present in a predetermined area Xp downstream of the expected stop position Ps.

[0037] If it is determined in step S3 that the moving object M does not exist in the predetermined area Xp, the blind spot area determination unit 20 determines in step S13 whether or not a blind spot area Xb exists in the predetermined area Xp. If it is determined that the blind spot area Xb does not exist in the predetermined area Xp, the processor 10 ends the process and does not change the vehicle speed profile. On the other hand, if it is determined that a blind spot Xb exists in the predetermined area Xp, the blind spot determination unit 20 identifies the position of the blind spot Xb in step S14. Then, in step S8, the threshold time setting unit 21 sets the threshold time depending on whether the blind spot Xb is located in the front direction Hv of the host vehicle at the expected stop position Ps.

[0038] On the other hand, if it is determined in step S3 that the moving object M exists in the predetermined area Xp, the host vehicle predicted trajectory acquisition unit 15 acquires the host vehicle predicted trajectory Rv in step S4. Next, in step S5, the moving object predictive trajectory calculation unit 14 calculates the moving object predictive trajectory Rm based on the current position, moving direction Hm, and moving speed of the moving object M.

[0039] Next, in step S6, the intersection determination unit 16 determines whether the host vehicle predicted trajectory Rv and the moving object predicted trajectory Rm intersect. If the intersection determination unit 16 determines that the host vehicle predicted trajectory Rv and the moving object predicted trajectory Rm do not intersect, the processor 10 ends the processing and does not change the vehicle speed profile.

[0040] On the other hand, if the intersection determination unit 16 determines that the host vehicle predicted trajectory Rv and the moving object predicted trajectory Rm intersect, in step S7, the movement direction angle calculation unit 19 calculates the movement direction angle formed by the front direction Hv of the host vehicle 1 at the expected stop position Ps and the movement direction Hm of the moving object M. Then, in step S8, the threshold time setting unit 21 sets the threshold time Tx based on the movement direction angle.

[0041] Next, in step S9, the intersection position calculation unit 17 calculates the intersection position Px. Note that the intersection position Px when the moving object M is not detected is the intersection position assumed when it is assumed that the moving object M is present in the blind spot area Xb and is moving in a predetermined direction at a predetermined speed so as to intersect with the host vehicle's predicted trajectory Rv. Next, in step S10, the virtual intersection time calculation unit 18 calculates the virtual intersection time Tk for each of one or more virtual positions Pk based on the vehicle speed profile generated by the vehicle speed profile generation unit 30.

[0042] Next, in step S11, the virtual intersection time determination unit 22 determines whether the virtual intersection time Tk calculated by the virtual intersection time calculation unit 18 is equal to or less than the threshold time Tx. If the virtual intersection time determination unit 22 determines that the virtual intersection time Tk is not equal to or less than the threshold time Tx (is greater than the threshold time Tx), the processor 10 ends the processing and does not change the vehicle speed profile.

[0043] On the other hand, if it is determined in step S11 that at least a portion of the virtual intersection time Tk is equal to or less than the threshold time Tx, then in step S12, the vehicle speed profile generator 30 shifts the deceleration reduction position Pd of the vehicle speed profile to the upstream side.

[0044] The braking control method performed by the braking control device 100 is not limited to the embodiment shown in Fig. 8. Specifically, the braking control device 100 may set the deceleration reduction position Pd to be further upstream when the moving direction angle is a first angle, based only on the moving direction angle, without calculating the virtual intersection time, compared to when the moving direction angle is a second angle smaller than the first angle.

[0045] As described above, when the detection device 102 detects a moving object M in a predetermined region Xp downstream of the expected stop position Ps, the brake control device 100 according to this embodiment calculates movement direction angles A1 to A3 formed by the forward direction Hv of the host vehicle 1 at the expected stop position Ps and the movement direction Hm of the moving object M. Then, the brake control device 100 generates a vehicle speed profile such that the deceleration relaxation position Pd of the vehicle speed profile is located more upstream when the movement direction angle is a first angle than when the movement direction angle is a second angle smaller than the first angle. In other words, the larger the movement direction angle, the more upstream the brake control device 100 sets the deceleration relaxation position Pd of the vehicle speed profile. This allows the brake control device 100 to control the deceleration dV of the host vehicle 1 according to the movement direction Hm of the moving object M detected downstream of the expected stop position Ps. That is, when the moving object M is moving toward the host vehicle 1 in the opposite direction to the forward direction Hv of the host vehicle 1, the brake control device 100 sets the deceleration reduction timing earlier than when the moving object M is moving toward the host vehicle 1 in a direction (forward direction) along the forward direction Hv of the host vehicle 1. As a result, when the moving object M is moving to approach the host vehicle 1 from the front, the timing (deceleration reduction timing) at which the occupant of the host vehicle 1 feels that "the host vehicle 1 will soon stop" can be made earlier than when the moving object M is approaching while moving in the same direction as the host vehicle 1. Therefore, the discomfort felt by the occupant of the host vehicle 1 can be reduced. Furthermore, for the moving object M, the deceleration reduction timing of the host vehicle 1 approaching the moving object M from the front is earlier than the deceleration reduction timing of the host vehicle 1 approaching the moving object M from behind. Therefore, the brake control device 100 can reduce the discomfort felt by the moving object M, such as a pedestrian. Furthermore, when the movement direction angle is smaller than a predetermined angle (for example, 90 degrees), the braking control device 100 does not advance the deceleration reduction timing more than necessary, thereby minimizing the impact of the deceleration of the vehicle 1 on following vehicles and preventing disruptions to traffic flow.

[0046] Furthermore, the braking control device 100 calculates the hypothetical intersection times between the host vehicle 1 and the moving object M based on the vehicle speed profile, and when it is determined that at least one hypothetical intersection time is equal to or shorter than a predetermined threshold time, corrects the vehicle speed profile so as to shift the deceleration relaxation position Pd upstream. This allows the braking control device 100 to quantitatively calculate the possibility of an intersection between the host vehicle 1 and the moving object M, and appropriately correct elements of the vehicle speed profile including the deceleration relaxation position Pd based on a comparison between the hypothetical intersection time and the threshold time.

[0047] Furthermore, the brake control device 100 sets the threshold time Tx when the movement direction angle is a first angle to be greater than the threshold time Tx when the movement direction angle is a second angle smaller than the first angle. That is, the larger the movement direction angle, the larger the threshold time Tx set by the brake control device 100. Here, the larger the threshold time Tx, the higher the probability that the vehicle speed profile generator 30 will correct the deceleration reduction position Pd further upstream (see FIG. 7). Therefore, the larger the movement direction angle, the higher the probability that the brake control device 100 will correct the deceleration reduction position Pd further upstream, and the brake control device 100 can control the deceleration dV of the host vehicle 1 in accordance with the movement direction Hm of the moving object M.

[0048] Furthermore, the brake control device 100 sets the threshold time Tx based on at least one of the size, shape, and behavior of the moving object M. As a result, the brake control device 100 can determine the attribute of the moving object M (for example, whether the moving object M is an adult pedestrian or a child pedestrian) based on one or more of the size (height and / or width), shape, and behavior pattern of the moving object M, and execute vehicle speed control in accordance with the attribute of the moving object M. Therefore, before stopping the vehicle 1 at the planned stop position Ps, the brake control device 100 can execute vehicle speed control at a deceleration that matches the perception of occupants of the vehicle 1 and pedestrians (moving object M) in accordance with the attribute of the moving object M downstream of the planned stop position Ps.

[0049] Furthermore, when the detection device 102 does not detect the moving object and a blind spot area Xb exists in the predetermined area Xp, the brake control device 100 sets the deceleration mitigation position Pd further upstream than when no blind spot area Xb exists. As a result, the brake control device 100 executes vehicle speed control according to the possibility that a moving object M exists in the blind spot area Xb, and therefore, even when the moving object M suddenly appears from the blind spot area Xb, it is possible to reduce the sense of discomfort felt by occupants of the vehicle 1 and pedestrians, etc. (moving object M).

[0050] Furthermore, when a blind spot Xb is located in the forward direction Hv of the host vehicle 1 at the expected stop position Ps, the brake control device 100 sets the deceleration reduction position Pd further upstream than when it is determined that the blind spot Xb is not located in the forward direction Hv. As a result, when there is a possibility that a moving object M is present in the blind spot Xb located in the forward direction Hv of the host vehicle 1, the brake control device 100 can advance the deceleration reduction timing compared to when the blind spot Xb is located in a direction other than the forward direction Hv. Therefore, even when the moving object M suddenly appears from the blind spot Xb located in the forward direction Hv of the host vehicle 1, the brake control device 100 can reduce the discomfort felt by occupants of the host vehicle 1 and pedestrians, etc. (the moving object M). Furthermore, when a blind spot Xb is located in a direction other than the forward direction Hv of the host vehicle 1, the brake control device 100 does not advance the deceleration reduction timing more than necessary, thereby minimizing the impact of deceleration of the host vehicle 1 on following vehicles and preventing disruptions to traffic flow.

[0051] Furthermore, when there are multiple blind spot areas Xb in the predetermined area Xp, the brake control device 100 calculates a deceleration relaxation position Pd for each of the multiple blind spot areas Xb, and selects the most upstream deceleration relaxation position Pd from the calculated multiple deceleration relaxation positions Pd to set the vehicle speed profile. That is, when there are multiple blind spot areas Xb in the predetermined area Xp and at least one blind spot area Xb is located in the forward direction Hv of the host vehicle 1 at the expected stop position Ps, the brake control device 100 selects the deceleration relaxation position Pd (the most upstream deceleration relaxation position Pd) corresponding to the blind spot Xb located in the forward direction Hv of the host vehicle 1. As a result, even when there are multiple blind spot areas Xb in the predetermined area Xp, when at least one blind spot area Xb is located in the forward direction Hv of the host vehicle 1, the brake control device 100 can advance the deceleration relaxation timing compared to when all blind spot areas Xb are located in directions other than the forward direction Hv of the host vehicle 1. Therefore, even if a moving object M suddenly appears from one of the multiple blind spot areas Xb, which is located in the front direction Hv of the vehicle 1, the braking control device 100 can reduce the discomfort felt by occupants of the vehicle 1 and pedestrians, etc. (moving object M).

[0052] The vehicle speed profile changed by the braking control device 100 is not limited to the example shown in FIG. For example, the vehicle speed profile generating unit 30 of the braking control device 100 may generate a second vehicle speed profile Q2 that has been changed to show the transition of deceleration shown in the solid line graphs in Figures 9 to 11. In the following description, the dashed line graphs in Figures 9 to 11 indicate the first vehicle speed profile Q1 before the change, similar to the dashed line graph in Figure 6(a). That is, in the following description, the vehicle speed profile when the movement direction angle is a predetermined first angle (for example, angles A2 and A3 shown in Figures 3 and 4) is the second vehicle speed profile Q2, and the vehicle speed profile when the movement direction angle is a second angle smaller than the first angle (for example, angle A1 shown in Figure 2) is the first vehicle speed profile Q1.

[0053] In the example shown in Figure 9, the vehicle speed profile generation unit 30 changes the deceleration relaxation position Pd and the reference deceleration dV0 when changing the vehicle speed profile from the first vehicle speed profile Q1 to the second vehicle speed profile Q2. Note that the deceleration start position Pb is not changed. Specifically, the vehicle speed profile generation unit 30 changes the reference deceleration dV0 to a reference deceleration dV02 that is higher than the reference deceleration dV01 of the first vehicle speed profile Q1. Furthermore, with regard to the deceleration relaxation position Pd, the vehicle speed profile generation unit 30 changes the deceleration relaxation position Pd0 of the first vehicle speed profile Q1 to a deceleration relaxation position Pd2 that is relatively upstream.

[0054] 9, the brake control device 100 sets the vehicle speed profile so that the deceleration start position Pb when the moving direction angle is a first angle is the same as the deceleration start position Pb when the moving direction angle is a second angle smaller than the first angle, and so that the reference deceleration dV02 when the moving direction angle is the first angle is higher than the reference deceleration dV01 when the moving direction angle is the second angle. This allows the brake control device 100 to set the deceleration reduction position Pd in ​​accordance with the moving direction Hm of the moving object M without changing the deceleration start position Pb (deceleration start timing) of the host vehicle 1. This allows the brake control device 100 to execute vehicle speed control at a deceleration that is suited to the perceptions of occupants of the host vehicle 1, pedestrians, etc. (moving object M) based on the moving direction Hm of the moving object M, while minimizing the impact on following vehicles of the host vehicle 1, and to decelerate the host vehicle 1 upstream of the expected stop position Ps.

[0055] 10, when the vehicle speed profile is changed from the first vehicle speed profile Q1 to the second vehicle speed profile Q2, the vehicle speed profile generation unit 30 first calculates the predicted reference deceleration RV02 that should be set to make the deceleration change rate equal to the specified change rate RdV1, assuming that the deceleration start position Pb0 is not changed. Then, the vehicle speed profile generation unit 30 determines whether the predicted reference deceleration RV02 is higher than a predetermined threshold deceleration dV03. Furthermore, when the vehicle speed profile generation unit 30 determines that the predicted reference deceleration RV02 is higher than the predetermined threshold deceleration dV03, the vehicle speed profile generation unit 30 sets the reference deceleration dV0 to the threshold deceleration dV0. 0 3. Then, the vehicle speed profile generation unit 30 changes the deceleration start position Pb to a deceleration start position Pb3 upstream of the previous deceleration start position Pb0 so that the deceleration change rate in the deceleration decrease section Dd3 becomes the specified change rate RdV1. Note that the threshold deceleration dV03 is an upper limit value of the deceleration rate at which the change in the vehicle speed of the host vehicle 1 does not have too much effect on the following vehicle, that is, at which the deceleration is not perceived as sudden from the perspective of the following vehicle. The threshold deceleration dV03 is set in advance experimentally.

[0056] 10, the brake control device 100 determines whether the reference deceleration dV0 is higher than a predetermined threshold deceleration dV03 based on the vehicle speed profile, and if it determines that the reference deceleration dV0 is higher than the threshold deceleration dV03, corrects the vehicle speed profile so that the reference deceleration dV0 becomes equal to the threshold deceleration dV03. As a result, the brake control device 100 can execute vehicle speed control at a deceleration that matches the perception of occupants of the vehicle 1, pedestrians, etc. (moving object M) based on the moving direction Hm of the moving object M, while minimizing the impact of the deceleration of the vehicle 1 on following vehicles, and can decelerate the vehicle 1 upstream of the expected stop position Ps.

[0057] 11, when the vehicle speed profile is changed from the first vehicle speed profile Q1 to the second vehicle speed profile Q2, the vehicle speed profile generation unit 30 changes the deceleration in the deceleration decrease section Dd1 so that there is a constant deceleration section Dz where the deceleration change rate is 0 (zero). That is, the vehicle speed profile generation unit 30 gradually decreases the deceleration in the deceleration decrease section Dd1. As a result, the braking control device 100 can reduce the calculation load on the processor 10 while performing vehicle speed control at a deceleration that matches the perception of occupants of the vehicle 1, pedestrians, etc. (moving object M) based on the moving direction Hm of the moving object M, and decelerate the vehicle 1 upstream of the expected stop position Ps.

[0058] If the moving object M is suddenly detected while the host vehicle 1 is traveling according to the vehicle speed profile in a state in which the moving object M has not been detected, the braking control device 100 may change the vehicle speed profile at that time. In this case, the braking control device 100 decelerates the host vehicle 1 according to the changed vehicle speed profile from the time when the detection device 102 detects the moving object M until the host vehicle 1 reaches the planned stop position Ps.

[0059] 100...Brake control device 1...Own vehicle 10...Processor 13...Moving object detection determination unit 19...Movement direction angle calculation unit 30... Vehicle speed profile generation unit 101...Braking actuator 102...Detection device M…moving object A1,A2,A3…Movement direction angle Hm...Movement direction Hv...Front direction Pd…Deceleration relaxation position Pb…Deceleration start position Ps: Planned stopping position Pv...Vehicle position Px…intersection position Rm…Predicted trajectory of moving object Rv...Predicted vehicle trajectory Tk...Virtual crossing time Tx: Threshold time Vc: Vehicle speed Xp…Specified area Xb…Blind area dV0…Reference deceleration dV3: Threshold deceleration

Claims

1. A braking control method using a processor to control a brake actuator of a host vehicle based on a vehicle speed profile based on a vehicle speed and a host vehicle position when the host vehicle travels along a predetermined host vehicle predicted trajectory, and a planned stopping position where the host vehicle is planned to stop before crossing a sidewalk based on road information, the vehicle speed profile is a profile in which the host vehicle starts deceleration at a deceleration start position upstream of the planned stop position, travels a predetermined section at a predetermined reference deceleration, and then the deceleration of the host vehicle decreases below the reference deceleration at a deceleration relaxation position downstream of the deceleration start position and upstream of the planned stop position, The processor: determining whether a detection device of the host vehicle has detected a moving object in a predetermined area downstream of the planned stop position; When it is determined that the detection device has detected the moving object, a movement direction angle formed by a front direction of the host vehicle and a movement direction of the moving object when the host vehicle travels along the host vehicle predicted trajectory and stops at the planned stop position is calculated; A braking control method that generates the vehicle speed profile so that the deceleration mitigation position, which is a position at which the deceleration of the vehicle is mitigated when the vehicle decelerates upstream of the planned stopping position, becomes more upstream the larger the movement direction angle.

2. The processor: When it is determined that the detection device has detected the moving object, acquiring a predicted vehicle trajectory of the host vehicle; Acquire the position, moving direction, and moving speed of the moving object; calculating a predicted moving object trajectory of the moving object based on the position, the moving direction, and the moving speed of the moving object; determining whether the predicted vehicle trajectory and the predicted moving object trajectory intersect; When it is determined that the predicted trajectory of the host vehicle and the predicted trajectory of the moving object intersect, an intersection position between the predicted trajectory of the host vehicle and the predicted trajectory of the moving object is calculated; calculating a virtual intersection time by dividing a distance between one or more virtual positions upstream of the intended stop position and the intersection position by a virtual vehicle speed corresponding to each of the virtual positions, based on the vehicle speed profile; determining whether at least one of the virtual crossing times is equal to or less than a predetermined threshold time; 2. The braking control method according to claim 1, wherein when it is determined that at least one of the virtual intersection times is equal to or shorter than a predetermined threshold time, the vehicle speed profile is corrected so as to change the deceleration mitigation position upstream.

3. The processor: The braking control method according to claim 2 , wherein the threshold time is set to be larger as the movement direction angle is larger.

4. The processor: determining an attribute of the moving object based on at least one of a size, a shape, and a behavior of the moving object; 4. The braking control method according to claim 2, wherein when the moving object is determined to be a child pedestrian based on the attributes, the threshold time is set to be longer than when the moving object is determined to be an adult pedestrian.

5. The processor: If the detection device determines that the moving object is not detected, it determines whether or not a blind spot area exists in the predetermined area; A braking control method according to any one of claims 1 to 4, wherein, when it is determined that the blind spot area exists, the deceleration mitigation position is set upstream of when it is determined that the blind spot area does not exist.

6. The processor: If it is determined that the blind spot area exists, it is determined whether or not the blind spot area is located in a front direction of the host vehicle at the intended stop position; 6. The braking control method according to claim 5, wherein, when it is determined that the blind spot area is located in the front direction, the deceleration mitigation position is set upstream of when it is determined that the blind spot area is not located in the front direction.

7. The processor: When a plurality of blind spot areas exist in the predetermined area, the deceleration mitigation position is calculated for each of the plurality of blind spot areas; The braking control method according to claim 6, wherein the vehicle speed profile is set by selecting the deceleration reduction position that is most upstream from the calculated plurality of deceleration reduction positions.

8. The processor: The braking control method according to any one of claims 1 to 7, wherein the vehicle speed profile is set such that the reference deceleration is increased without changing the deceleration start position as the movement direction angle increases.

9. The processor: determining whether the reference deceleration is higher than a predetermined threshold deceleration based on the vehicle speed profile; 9. The brake control method according to claim 1, wherein, when it is determined that the reference deceleration is higher than the threshold deceleration, the vehicle speed profile is corrected so that the reference deceleration becomes the threshold deceleration.

10. a brake control device that uses a processor to control a brake actuator of the host vehicle based on a vehicle speed profile that is based on a vehicle speed and a vehicle position of the host vehicle when the host vehicle travels along a predetermined host vehicle predicted trajectory, and a planned stop position where the host vehicle is planned to stop before crossing a sidewalk based on road information, the vehicle speed profile is a profile in which the host vehicle starts deceleration at a deceleration start position upstream of the planned stop position, travels a predetermined section at a predetermined reference deceleration, and then the deceleration of the host vehicle decreases below the reference deceleration at a deceleration relaxation position downstream of the deceleration start position and upstream of the planned stop position, The processor: a moving object detection determination unit that determines whether a detection device of the host vehicle has detected a moving object in a predetermined area downstream of the planned stop position; a movement direction angle calculation unit that calculates a movement direction angle between a front direction of the host vehicle and a movement direction of the moving object when the host vehicle travels along the host vehicle predicted trajectory and stops at the planned stop position, if the detection device determines that the moving object has been detected; a vehicle speed profile generation unit that generates the vehicle speed profile so that the deceleration mitigation position, which is a position at which the deceleration of the vehicle is mitigated when the vehicle decelerates upstream of the planned stopping position, becomes more upstream the larger the movement direction angle.

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