Braking control device

Abstract

To perform vehicle stop control which makes it possible to both give a sense of stopping to vehicle occupants and improve the occupants' comfort when the vehicle stops.SOLUTION: A processing circuit 51 of a braking control device 50 functions as: a control unit M21 that, when applying a braking force to a vehicle 10 to stop it, performs stop control to control the vehicle braking force to suppress changes in the attitude of the vehicle 10 associated with the stop; a position acquisition unit M10 that acquires the vehicle stop position; a distance acquisition unit M11 that acquires the distance between the vehicle stop position and the vehicle 10; and a setting unit M19 that sets the degree to which changes in the attitude of the vehicle 10 are suppressed by the execution of the stop control based on the distance.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a brake control device provided in a vehicle. [Background technology]

[0002] Patent Document 1 discloses a vehicle control device that performs stopping control to suppress changes in the vehicle's posture when the vehicle is stopped by reducing the braking force applied to the vehicle immediately before the vehicle stops. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-28913 Summary of the Invention [Problem to be solved by the invention]

[0004] By implementing the above-described stopping control, the vehicle's posture change during stopping is minimized, thereby improving the comfort of the vehicle's occupants during stopping. However, the sense of stopping, which is the sensation that the occupants get that the vehicle has stopped, is reduced. Therefore, when the above-described stopping control is implemented in a situation where there is a stopping position guide in the vehicle's direction of travel, the occupants may feel uneasy because they do not easily get the sense of stopping. Note that stopping position guides include, for example, obstacles that may hinder the vehicle's travel, such as a preceding vehicle, and traffic information that urges the vehicle to stop, such as road signs and traffic lights. [Means for solving the problem]

[0005] A braking control device for solving the above problem is a device that performs stopping control by applying a braking force to a vehicle to stop the vehicle, controlling the braking force to suppress changes in the vehicle's attitude due to stopping. The braking control device includes a position acquisition unit that acquires a stopping position indicated by a stopping position guide where the vehicle should be stopped, a distance acquisition unit that acquires the distance between the stopping position and the vehicle, and a setting unit that sets a degree of suppression of changes in the vehicle's attitude due to the execution of the stopping control, based on the distance acquired by the distance acquisition unit. [Effects of the Invention]

[0006] The braking control device has the effect of being able to provide the vehicle occupants with a sense of stopping when the vehicle stopping control is performed, and to improve the comfort of the occupants when the vehicle is stopped. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a vehicle equipped with a braking control device according to an embodiment. [Figure 2] FIG. 2 is a timing chart when vehicle-stop braking control is performed when stopping the vehicle by applying braking force. [Figure 3] FIG. 3 is a flowchart showing a series of processes executed by the braking control device of FIG. [Figure 4] FIG. 4 is a flowchart showing a series of processes executed by the braking control device of FIG. [Figure 5] FIG. 5 is a timing chart showing a case where braking control is performed when the vehicle is stationary in a situation where an obstacle is present in the traveling direction of the vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of the brake control device will be described below with reference to FIGS. 1 illustrates a vehicle 10 equipped with a brake control device 50. The vehicle 10 is equipped with a brake operating member 11, a plurality of wheels, a plurality of friction brakes, and a brake actuator 30. The brake operating member 11 is a member that is operated by the driver when applying a braking force to the vehicle 10. An example of the brake operating member 11 is a brake pedal. The plurality of wheels include two front wheels 12 and two rear wheels 13.

[0009] <Friction brake> The multiple friction brakes each apply a braking force to the corresponding wheel. Of the multiple friction brakes, the friction brake corresponding to the front wheel 12 is referred to as "friction brake 20A," and the friction brake corresponding to the rear wheel 13 is referred to as "friction brake 20B." Friction brakes 20A and 20B each have a wheel cylinder 21, a rotating body 22, and a friction portion 23. Rotating body 22 rotates integrally with the wheel. Therefore, braking force is applied to the wheel by pressing friction portion 23 against rotating body 22. The force pressing friction portion 23 against rotating body 22 increases as the wheel hydraulic pressure, which is the hydraulic pressure in wheel cylinder 21, increases. Therefore, friction brakes 20A and 20B can apply a greater braking force to the wheel as the wheel hydraulic pressure increases.

[0010] In the following description, the braking force applied to the front wheels 12 by the friction brake 20A will be referred to as the "front wheel friction braking force BPFF." The braking force applied to the rear wheels 13 by the friction brake 20B will be referred to as the "rear wheel friction braking force BPFR." The sum of the braking forces applied to the multiple wheels 12, 13 will be referred to as the "vehicle braking force BPAl." In the vehicle 10, the sum of the front wheel friction braking force BPFF and the rear wheel friction braking force BPFR corresponds to the vehicle braking force BPAl.

[0011] <Braking actuator> The brake actuator 30 controls the wheel hydraulic pressure in the plurality of wheel cylinders 21 to control the braking force applied to the wheels 12, 13. For example, the brake actuator 30 has a pressure source that supplies brake fluid to the plurality of wheel cylinders 21. The pressure source is, for example, an electric pump and an electric cylinder. The brake actuator 30 can adjust the wheel hydraulic pressure in the wheel cylinder 21 for the front wheels 12 and the wheel hydraulic pressure in the wheel cylinder 21 for the rear wheels 13 separately.

[0012] <Detection system> The detection system of the vehicle 10 includes a plurality of sensors that output detection signals to the braking control device 50. The plurality of sensors includes a brake sensor 101, a plurality of wheel speed sensors 102, and a longitudinal acceleration sensor 103.

[0013] The brake sensor 101 detects information related to the operation of the brake operating member 11 by the driver. One example of the brake sensor 101 is a stroke sensor that detects the amount of operation of the brake operating member 11 by the driver. The amount of operation based on the detection signal of the brake sensor 101 is referred to as the "braking operation amount X." The detection system may also include a sensor that detects the operating force of the brake operating member 11 by the driver.

[0014] A wheel speed sensor 102 is provided for each of the multiple wheels. Each of the multiple wheel speed sensors 102 detects the rotational speed of the corresponding wheel. The rotational speed of the wheel based on the detection signal of the wheel speed sensor 102 is referred to as the "wheel speed VW." The traveling speed of the vehicle 10 calculated based on the wheel speeds VW of the multiple wheels 12, 13 is referred to as the "vehicle speed VS."

[0015] The longitudinal acceleration sensor 103 detects the longitudinal acceleration of the vehicle 10 out of the accelerations acting on the vehicle 10. The longitudinal acceleration of the vehicle 10 based on the detection signal of the longitudinal acceleration sensor 103 is referred to as "longitudinal acceleration Gx."

[0016] The detection system of the vehicle 10 includes an exterior monitoring device 60. The exterior monitoring device 60 includes an imaging device 61 that captures images outside the vehicle, and a monitoring control device 62. The imaging device 61 includes, for example, multiple cameras. The multiple cameras include a camera that captures images in the traveling direction of the vehicle 10. The imaging device 61 outputs image data, which is data of images captured by the cameras, to the monitoring control device 62.

[0017] An example of the monitoring control device 62 is an electronic control device. The monitoring control device 62 analyzes image data input from the imaging device 61. For example, the monitoring control device 62 determines, as a result of analyzing the image data, whether or not there is a stopping position guide in the traveling direction of the vehicle 10. A stopping position guide is something that guides the vehicle 10 to stop. Things that guide the vehicle 10 to stop include obstacles that may hinder the traveling of the vehicle 10 and traffic information that urges the vehicle to stop, such as road signs and traffic lights.

[0018] The "obstacles" include, for example, other vehicles and pedestrians. The "road signs" include, for example, signs requesting a stop and road markings. When the monitoring control device 62 determines that a stop position guide is present in the traveling direction of the vehicle 10, it sets a stop position where the vehicle 10 should be stopped. For example, when the stop position guide present in front of the vehicle 10 is the above-mentioned obstacle, the monitoring control device 62 sets a position in front of the obstacle as the stop position. A position in front of the obstacle is a position where the vehicle 10 can avoid contact with the obstacle. Also, for example, when the stop position guide present in front of the vehicle 10 is the above-mentioned traffic information, the monitoring control device 62 sets a position where the traffic information requests the vehicle to stop as the stop position. An example of a position where the traffic information requests the vehicle to stop is a position where a white stop lane is drawn on the road surface.

[0019] Once the stop position is set, the monitoring control device 62 measures the distance DIS from the vehicle 10 (i.e., the host vehicle) to the stop position. The monitoring control device 62 also measures an approach speed SPA, which is the speed at which the vehicle 10 (i.e., the host vehicle) approaches the stop position. The monitoring control device 62 then transmits information to the braking control device 50 regarding whether or not a stop position guide is present in the traveling direction of the vehicle 10. If a stop position guide is present in the traveling direction of the vehicle 10, the monitoring control device 62 also transmits the measured distance DIS and approach speed SPA to the braking control device 50.

[0020] <Vehicle control panel> The operation unit 70 of the vehicle 10 is a user interface that allows the occupant to set the level of comfort for the occupant when stopping the vehicle 10 by applying braking force. As will be described in detail later, the operation unit 70 allows the occupant to set the level of comfort for the occupant when stopping braking control is performed when braking force is applied to the vehicle 10 to stop it. In the example shown in FIG. 1 , if the occupant wants to increase the comfort level, the occupant shifts the operation knob 71 to the right in the figure. Then, the operation unit 70 transmits comfort information, which is information related to the level of comfort set by the occupant's operation, to the braking control device 50.

[0021] <Brake control device> The braking control device 50 includes a processing circuit 51. One example of the processing circuit 51 is an electronic control device. In this case, the processing circuit 51 includes a CPU 52, a first memory 53, and a second memory 54. The first memory 53 stores a control program executed by the CPU 52. The second memory 54 stores calculation results of the CPU 52, etc. When the CPU 52 executes the control program stored in the first memory 53, the processing circuit 51 controls the brake actuator 30 to activate the plurality of friction brakes 20A, 20B. In other words, the processing circuit 51 can adjust the vehicle braking force BPAl by activating the plurality of friction brakes 20A, 20B.

[0022] <Outline of braking control when vehicle is stationary> The processing circuit 51 performs braking control during vehicle stoppage when the driver is operating the brake operating member 11. The braking control during vehicle stoppage is an example of "vehicle stoppage control" that controls the braking force to suppress changes in the posture of the vehicle 10 that occur when the vehicle 10 is stopped by applying a braking force to the vehicle 10.

[0023] The vehicle stop braking control will be described with reference to Fig. 2. Fig. 2 shows an example in which a vehicle stop maintenance braking force BPth is set as a holding braking force BPh, which will be described later. The vehicle stop maintenance braking force BPth is the minimum vehicle braking force required to keep the vehicle 10 stopped on the road surface on which the vehicle 10 is traveling, or a vehicle braking force slightly greater than the minimum vehicle braking force.

[0024] At timing t11 while the vehicle 10 is traveling, the driver begins to operate the brake operating member 11. In this case, as shown in FIG. 2B, the processing circuit 51 derives a required braking force BPRq. The required braking force BPRq is a required value for the vehicle braking force BPAl. For example, the processing circuit 51 derives the required braking force BPRq so that the magnitude of the required braking force BPRq increases as the braking operation amount X of the brake operating member 11 increases. When the vehicle speed VS of the vehicle 10 is greater than the first vehicle speed determination value VSth1, as before timing t12, the processing circuit 51 sets the required braking force BPRq as the command braking force BPTr, as shown in FIG. 2D. Then, the processing circuit 51 controls the brake actuator 30 so that the vehicle braking force BPAl becomes the command braking force BPTr.

[0025] When a braking force is applied to the vehicle 10 in this manner, the vehicle speed VS decreases as shown in Fig. 2(A). Also, as shown in Fig. 2(C), the absolute value of the longitudinal acceleration Gx increases as the vehicle braking force BPAl increases.

[0026] When the vehicle speed VS reaches the first vehicle speed determination value VSth1 at timing t12, the processing circuit 51 starts stationary braking control. The first vehicle speed determination value VSth1 is an example of a threshold value for setting the start timing of stationary braking control. From timing t12, the processing circuit 51 starts an increase correction process for the stationary braking control. In the increase correction process, the processing circuit 51 sets a vehicle braking force greater than the required braking force BPRq as the command braking force BPTr. For example, the processing circuit 51 sets the sum of the required braking force BPRq and the offset value ΔBP as the command braking force BPTr. Then, the processing circuit 51 controls the brake actuator 30 so that the vehicle braking force BPAl becomes the command braking force BPTr. As a result, even if the required braking force BPRq remains the same, the absolute value of the longitudinal acceleration Gx of the vehicle 10 becomes greater by the amount of the offset value ΔBP than before timing t12.

[0027] At timing t13, the vehicle speed VS becomes the second vehicle speed determination value VSth2. A vehicle speed smaller than the first vehicle speed determination value VSth1 is set as the second vehicle speed determination value VSth2. When the vehicle speed VS is equal to or smaller than the second vehicle speed determination value VSth2, it is assumed that the vehicle 10 is approaching the predicted stop position PS. The predicted stop position PS is a predicted position where the vehicle 10 will stop. The processing circuit 51 shifts the processing of the stop-time braking control from an increase correction processing to a decrease correction processing. In the decrease correction processing, the processing circuit 51 reduces the command braking force BPTr. Then, the processing circuit 51 controls the brake actuator 30 so that the vehicle braking force BPAl becomes the command braking force BPTr. By performing the decrease correction processing in this way, the vehicle braking force BPAl becomes smaller than the required braking force BPRq. As a result, even if the required braking force BPRq remains the same, the absolute value of the longitudinal acceleration Gx of the vehicle 10 gradually decreases.

[0028] At timing t14, the command braking force BPTr becomes equal to the held braking force BPh. At timing t14, in the decrease correction process, the processing circuit 51 holds the command braking force BPTr at the held braking force BPh.

[0029] In the reduction correction process, the process of reducing the command braking force BPTr to the held braking force BPh is referred to as a "reduction process." In the reduction correction process, the process of maintaining the command braking force BPTr at the held braking force BPh is referred to as a "maintenance process."

[0030] Before the vehicle 10 stops, a deceleration inertia force, which is an inertial force resulting from deceleration, acts on the vehicle 10. The deceleration inertia force is correlated with the vehicle braking force BPAl and acts on the vehicle 10 in the traveling direction. Before the vehicle 10 stops, the longitudinal acceleration Gx has a value corresponding to the deceleration inertia force. However, when the vehicle 10 stops at timing t15, the deceleration inertia force becomes 0 (zero). Therefore, as shown in FIG. 2(C), the longitudinal acceleration Gx fluctuates before and after the vehicle 10 stops.

[0031] When vehicle-stop braking control is being implemented, the vehicle braking force BPAl when the vehicle is stopped is smaller than the required braking force BPRq. Therefore, when the vehicle is stopped while vehicle-stop braking control is being implemented, the fluctuation in the longitudinal acceleration Gx when the vehicle is stopped is smaller than when the vehicle is stopped without vehicle-stop braking control being implemented. As described above, the smaller the fluctuation in the longitudinal acceleration Gx, the smaller the change in the posture of the vehicle 10 that occurs when the vehicle is stopped, thereby improving the comfort of the occupants when the vehicle is stopped. On the other hand, if the vehicle braking force BPAl when the vehicle is stopped is reduced to improve the comfort of the occupants when the vehicle is stopped, the feeling of the vehicle being stopped that the occupants feel when the vehicle is stopped is reduced. The feeling of the vehicle being stopped is the feeling that the occupants feel that the vehicle 10 has stopped.

[0032] At timing t15, when the processing circuit 51 determines that the vehicle 10 has stopped, it transitions the stationary braking control processing from the reduction correction processing to the degeneration processing. In the degeneration processing, the processing circuit 51 increases the command braking force BPTr. For example, the processing circuit 51 increases the command braking force BPTr to the required braking force BPRq. The processing circuit 51 controls the brake actuator 30 based on the command braking force BPTr, thereby increasing the vehicle braking force BPAl. When the command braking force BPTr becomes equal to the required braking force BPRq at timing t16, the processing circuit 51 ends the stationary braking control.

[0033] <Functional configuration of processing circuit> The functional configuration of the processing circuit 51 will be described with reference to Fig. 1. The CPU 52 executes the control program in the first memory 53, causing the processing circuit 51 to function as multiple functional units. These multiple functional units are functional units for applying braking force to the vehicle 10 to bring it to a stop. The multiple functional units include, for example, a position acquisition unit M10, a distance acquisition unit M11, an approach speed acquisition unit M13, an operation information acquisition unit M15, a required braking force derivation unit M17, a setting unit M19, and a control unit M21.

[0034] <Position acquisition part> The position acquisition unit M10 acquires the stop position indicated by the stop position guide. For example, when the monitoring control device 62 determines that a stop position guide exists in the traveling direction of the vehicle 10, the monitoring control device 62 transmits various information related to the stop position guide to the braking control device 50. The position acquisition unit M10 acquires the stop position based on the various information transmitted by the monitoring control device 62. For example, when the stop position guide exists in the traveling direction of the vehicle 10 during vehicle braking, the distance acquisition unit M11 acquires the stop position at every predetermined control cycle.

[0035] <Distance acquisition part> When a stop position guide exists in the traveling direction of the vehicle 10, the distance acquisition unit M11 acquires the distance DIS transmitted from the monitoring control device 62 as the distance between the stop position and the vehicle 10 (i.e., the vehicle itself). For example, when the stop position guide exists in the traveling direction of the vehicle 10 during vehicle braking, the distance acquisition unit M11 acquires the distance DIS at every predetermined control cycle.

[0036] <Approach speed acquisition part> When the stop position guide exists in the traveling direction of the vehicle 10, the approach speed acquisition unit M13 acquires the approach speed SPA transmitted from the monitoring control device 62 as the speed at which the vehicle 10 (i.e., the vehicle itself) approaches the stop position. For example, when the stop position guide exists in the traveling direction of the vehicle 10 during vehicle braking, the approach speed acquisition unit M13 acquires the approach speed SPA for each predetermined control cycle. In particular, the approach speed acquisition unit M13 acquires the approach speed SPA at the start timing of the stop-time braking control as the reference approach speed SPAB.

[0037] <Operation information acquisition section> The operation information acquisition unit M15 acquires the comfort information transmitted from the operation unit 70. Then, the operation information acquisition unit M15 acquires the level of comfort indicated by the acquired comfort information as an index value IND of the comfort when the vehicle is stopped. In this embodiment, the larger the index value IND, the higher the comfort desired by the occupant.

[0038] <Required braking force derivation section> The required braking force derivation unit M17 derives the required braking force BPRq. When the driver is operating the brake operating member 11, the required braking force derivation unit M17 derives the required braking force BPRq based on the braking operation amount X of the brake operating member 11. When vehicle deceleration is requested by another control device, the required braking force derivation unit M17 derives a braking force corresponding to that request as the required braking force BPRq.

[0039] <Settings section> The setting unit M19 sets the degree of suppression of changes in the posture of the vehicle 10 due to the execution of the stationary braking control. In this embodiment, the setting unit M19 sets the maintained braking force BPh as the suppression degree. For example, when the setting unit M19 reduces the suppression degree, the setting unit M19 increases the maintained braking force BPh.

[0040] The setting unit M19 sets the maintained braking force BPh based on the distance DIS acquired by the distance acquisition unit M11. For example, the setting unit M19 sets the maintained braking force BPh so that the maintained braking force BPh increases as the distance DIS acquired before the start of the stationary braking control decreases. This allows the setting unit M19 to decrease the degree of suppression as the distance DIS acquired before the start of the stationary braking control decreases.

[0041] When the required braking force BPRq calculated before the start of the stationary braking control is large, the setting unit M19 sets the maintained braking force BPh to be larger than when the required braking force BPRq is small. For example, when the required braking force BPRq is equal to or larger than the specified braking force BPA, the setting unit M19 sets the maintained braking force BPh to be larger than when the required braking force BPRq is smaller than the specified braking force BPA. In this case, it is preferable that the specified braking force BPA be set as the criterion for determining whether the required braking force BPRq is small. As a result, when the required braking force BPRq is large, the setting unit M19 can reduce the degree of suppression compared to when the required braking force BPRq is small.

[0042] The setting unit M19 sets the maintained braking force BPh based on the comfort index value IND acquired by the operation information acquisition unit M15. For example, the setting unit M19 sets the maintained braking force BPh so that the maintained braking force BPh increases as the comfort index value IND acquired before the start of the stationary braking control decreases. This allows the setting unit M19 to set the suppression degree by taking into account the comfort information acquired by the operation information acquisition unit M15.

[0043] When the stop position guide detected by the vehicle exterior monitoring device 60 is not an obstacle, the setting unit M19 determines whether the predicted stop position PS exceeds the stop position acquired by the position acquisition unit M10 during vehicle braking. If the predicted stop position PS exceeds the stop position, there is a possibility that the vehicle 10 will stop after passing the stop position. Therefore, when the predicted stop position PS exceeds the stop position, the setting unit M19 sets the holding braking force BPh to be larger than when the predicted stop position PS does not exceed the stop position. As a result, when it is predicted that the vehicle 10 will stop after passing the stop position, the setting unit M19 can reduce the degree of suppression compared to when it is predicted that the vehicle 10 will stop without passing the stop position.

[0044] When the approach speed SPA acquired by the approach speed acquisition unit M13 increases during stationary braking control, the setting unit M19 corrects the maintained braking force BPh so that the maintained braking force BPh increases. For example, when the approach speed SPA is greater than the reference approach speed SPAB during stationary braking control, the setting unit M19 increases the maintained braking force BPh. In this case, the setting unit M19 may increase the amount of increase in the maintained braking force BPh the greater the difference between the approach speed SPA and the reference approach speed SPAB. This allows the setting unit M19 to set the suppression degree to decrease as the approach speed SPA acquired during stationary braking control increases. On the other hand, when the approach speed SPA acquired during stationary braking control decreases, the setting unit M19 does not correct the suppression degree, i.e., the maintained braking force BPh.

[0045] When the vehicle-stop braking control is being maintained or reduced, the approach speed SPA may become greater than the reference approach speed SPAB. In such a case, the setting unit M19 does not modify the maintained braking force BPh even if the approach speed SPA is greater than the reference approach speed SPAB.

[0046] <Control unit> When the start condition for the stationary braking control is satisfied, the control unit M21 starts the stationary braking control. At this time, the control unit M21 creates a profile of the vehicle braking force BPAl during the stationary braking control based on the suppression degree set by the setting unit M19, i.e., the maintained braking force BPh. As described above, the maintained braking force BPh may be modified during the stationary braking control. In such a case, the control unit M21 modifies the profile in accordance with the modification of the maintained braking force BPh. Then, the control unit M21 derives the command braking force BPTr according to the profile, as shown in FIG. 2(D).

[0047] Specifically, in the increasing correction process of the stationary braking control, the control unit M21 derives the sum of the required braking force BPRq and the offset value ΔBP as the command braking force BPTr, and then operates the brake actuator 30 based on the command braking force BPTr.

[0048] When a condition for transitioning from the increasing correction process to the decreasing correction process is met during the execution of the increasing correction process, the control unit M21 ends the increasing correction process and starts the decreasing correction process. In the decreasing process of the decreasing correction process, the control unit M21 reduces the command braking force BPTr toward the held braking force BPh. When the command braking force BPTr reduces to the held braking force BPh, the control unit M21 executes the holding process of the decreasing correction process to hold the command braking force BPTr at the held braking force BPh. Then, the control unit M21 operates the brake actuator 30 based on the command braking force BPTr at that time.

[0049] When a condition for transitioning from the reduction correction process to the degeneration process is met during the execution of the reduction correction process, the control unit M21 ends the reduction correction process and starts the degeneration process. In the degeneration process, the control unit M21 increases the command braking force BPTr to the required braking force BPRq. Then, the control unit M21 operates the brake actuator 30 based on the command braking force BPTr at that time.

[0050] <Process flow for setting holding braking force> A series of processes executed by the processing circuit 51 when setting the holding braking force BPh will be described with reference to Fig. 3. The processing circuit 51 repeatedly executes the series of processes shown in Fig. 3 when the vehicle is braking.

[0051] In step S11, the processing circuit 51 determines whether or not stationary braking control is being performed. If stationary braking control is being performed (S11: YES), the processing circuit 51 proceeds to step S31. On the other hand, if stationary braking control is not being performed (S11: NO), the processing circuit 51 proceeds to step S13.

[0052] In step S13, the processing circuit 51 obtains the distance DIS. In the next step S15, the processing circuit 51 sets a first correction coefficient β1 according to the distance DIS. The first correction coefficient β1 is a correction gain used when deriving the holding braking force BPh. The processing circuit 51 derives a value equal to or greater than 1 as the first correction coefficient β1. In this case, the processing circuit 51 derives the first correction coefficient β1 so that it increases as the distance DIS becomes shorter. The processing circuit 51 derives 1 as the first correction coefficient β1 when at least one of the following conditions (A1) and (A2) is satisfied. A criterion for determining whether an obstacle is sufficiently far from the vehicle 10 (i.e., the host vehicle) is set as the distance determination value DISth.

[0053] (A1) When no stopping position guide object is detected in the direction of travel of the vehicle 10. (A2) Although a stop position guide object is detected in the traveling direction of the vehicle 10, the distance DIS is equal to or greater than the distance determination value DISth.

[0054] In the following step S17, the processing circuit 51 sets a second correction coefficient β2 according to the required braking force BPRq. The second correction coefficient β2 is a correction gain used when deriving the maintained braking force BPh. The processing circuit 51 derives a value equal to or greater than 1 as the second correction coefficient β2. In this case, when the required braking force BPRq is large, the processing circuit 51 derives the second correction coefficient β2 so that it is larger than when the required braking force BPRq is small. For example, when the required braking force BPRq is less than the specified braking force BPA, the processing circuit 51 derives the second correction coefficient β2 as 1, whereas when the required braking force BPRq is equal to or greater than the specified braking force BPA, the processing circuit 51 derives the second correction coefficient β2 as a value greater than 1. In this case, when the required braking force BPRq is equal to or greater than the specified braking force BPA, the processing circuit 51 may derive the second correction coefficient β2 so that it increases as the required braking force BPRq increases.

[0055] In the next step S19, the processing circuit 51 obtains the comfort index value IND. In the next step S21, the processing circuit 51 sets a third correction coefficient β3 according to the index value IND. The third correction coefficient β3 is a correction gain used when deriving the holding braking force BPh. The processing circuit 51 derives a value equal to or greater than 1 as the third correction coefficient β3. In this case, the processing circuit 51 derives the third correction coefficient β3 so that it increases as the index value IND decreases. Note that if the index value IND is relatively small, it can be assumed that the occupant desires a greater feeling of stopping rather than increased comfort when the vehicle is stopped.

[0056] Then, in step S23, the processing circuit 51 derives a maintained braking force BPh within a range less than the required braking force BPRq. Specifically, the processing circuit 51 derives the maintained braking force BPh by correcting the vehicle stop maintenance braking force BPth with multiple correction coefficients β1, β2, and β3. For example, the processing circuit 51 derives the maintained braking force BPh as the product of the vehicle stop maintenance braking force BPth, the first correction coefficient β1, the second correction coefficient β2, and the third correction coefficient β3. As a result, the processing circuit 51 can increase the maintained braking force BPh as the distance DIS becomes shorter. When the required braking force BPRq is large, the processing circuit 51 can increase the maintained braking force BPh more than when the required braking force BPRq is small. The processing circuit 51 can increase the maintained braking force BPh as the passenger's required comfort level becomes lower.

[0057] In the next step S25, the processing circuit 51 determines whether or not there is a possibility that the vehicle 10 will stop beyond the stopping position. For example, the processing circuit 51 derives a predicted stopping position PS based on the current vehicle body speed VS and the deceleration DVS of the vehicle 10. Then, the processing circuit 51 compares the predicted stopping position PS with the stopping position to determine whether or not there is a possibility that the vehicle 10 will stop beyond the stopping position. If the processing circuit 51 determines that there is a possibility that the vehicle 10 will stop beyond the stopping position (S25: YES), the processing circuit 51 proceeds to step S27. On the other hand, if the processing circuit 51 determines that there is no possibility that the vehicle 10 will stop beyond the stopping position (S25: NO), the processing circuit 51 temporarily terminates the series of processes shown in FIG. 3.

[0058] In step S27, the processing circuit 51 corrects the maintained braking force BPh set in step S23 by increasing it. For example, the processing circuit 51 derives the sum of the maintained braking force BPh set in step S23 and a predetermined first correction braking force α1 as a new maintained braking force BPh. However, if the sum of the maintained braking force BPh and the first correction braking force α1 is equal to or greater than the required braking force BPRq, the processing circuit 51 does not need to correct the maintained braking force BPh by increasing it. After that, the processing circuit 51 temporarily ends the series of processes shown in FIG. 3.

[0059] In step S31, the processing circuit 51 acquires the approach speed SPA. In the following step S33, the processing circuit 51 determines whether the approach speed SPA acquired in step S31 is greater than the reference approach speed SPAB. If the approach speed SPA is greater than the reference approach speed SPAB (S33: YES), the processing circuit 51 proceeds to step S35. On the other hand, if the approach speed SPA is equal to or less than the reference approach speed SPAB (S33: NO), the processing circuit 51 temporarily ends the series of processes shown in FIG. 3. In this case, the processing circuit 51 does not modify the maintained braking force BPh during the execution of the stationary braking control. Note that if no stationary position guide is detected in the traveling direction of the vehicle 10, the processing circuit 51 cannot acquire the approach speed SPA in step S31. In such a case, the processing circuit 51 temporarily ends the series of processes shown in FIG. 3 without modifying the maintained braking force BPh.

[0060] In step S35, the processing circuit 51 determines whether the holding process or the degeneration process is being executed. If the holding process or the degeneration process is being executed (S35: YES), the processing circuit 51 temporarily ends the series of processes shown in FIG. 3. That is, the processing circuit 51 does not modify the held braking force BPh. On the other hand, if the processing circuit 51 is not executing either the holding process or the degeneration process (S35: NO), the processing circuit 51 shifts the process to step S37. That is, if the processing circuit 51 is executing the increase correction process or the decrease correction process, the processing circuit 51 shifts the process to step S37.

[0061] In step S37, the processing circuit 51 corrects the maintained braking force BPh so that it becomes larger. For example, the processing circuit 51 derives the sum of the maintained braking force BPh and a predetermined second correction braking force α2 as a new maintained braking force BPh. The second correction braking force α2 may be the same magnitude as the first correction braking force α1, or may be a magnitude different from the first correction braking force α1. However, if the sum of the maintained braking force BPh and the second correction braking force α2 is equal to or greater than the required braking force BPRq, the processing circuit 51 does not need to correct the maintained braking force BPh. After that, the processing circuit 51 temporarily ends the series of processes shown in FIG. 3.

[0062] In this embodiment, the processing of step S13 is executed by the processing circuitry 51 functioning as a distance acquisition unit M11. The processing of step S19 is executed by the processing circuitry 51 functioning as an operation information acquisition unit M15. The processing of step S31 is executed by the processing circuitry 51 functioning as an approach speed acquisition unit M13. The processing of steps S15, S17, S21, S23, S27, S35, and S37 is executed by the processing circuitry 51 functioning as a setting unit M19.

[0063] <Process flow for controlling vehicle braking force> A series of processes executed by the processing circuit 51 when performing braking control during a stop will be described with reference to Fig. 4. When stopping the vehicle 10 by applying a braking force, the processing circuit 51 repeatedly executes the series of processes shown in Fig. 4.

[0064] In step S51, the processing circuit 51 determines whether or not a start condition for the stationary braking control is satisfied. For example, as shown in FIG. 2, the processing circuit 51 determines that the start condition is satisfied when the vehicle body speed VS becomes equal to or less than the first vehicle body speed determination value VSth1 from a state in which the vehicle body speed VS is greater than the first vehicle body speed determination value VSth1. If the processing circuit 51 determines that the start condition is satisfied (S51: YES), the processing circuit 51 proceeds to step S53. On the other hand, if the processing circuit 51 determines that the start condition is not satisfied (S51: NO), the processing circuit 51 temporarily ends the series of processes shown in FIG. 4.

[0065] The first vehicle body speed determination value VSth1 is set based on the maintained braking force BPh that is set through the execution of the series of processes shown in Fig. 3. For example, the larger the maintained braking force BPh, the smaller the first vehicle body speed determination value VSth1 becomes.

[0066] In step S53, the processing circuit 51 performs braking control when the vehicle is stationary. Specifically, in step S55, the processing circuit 51 executes an increasing correction process. In the increasing correction process, the processing circuit 51 sets a vehicle braking force greater than the required braking force BPRq as the command braking force BPTr to compensate for the extension of the braking distance of the vehicle 10 resulting from the execution of the decreasing correction process. That is, the offset value ΔBP shown in FIG. 2(D) is the braking force correction amount for compensating for the extension of the braking distance of the vehicle 10 resulting from the execution of the decreasing correction process. The processing circuit 51 operates the brake actuator 30 based on the command braking force BPTr.

[0067] In the next step S57, the processing circuit 51 determines whether or not a transition condition from the increasing correction processing to the decreasing correction processing is satisfied. For example, as shown in Fig. 2, the processing circuit 51 determines that the transition condition is satisfied when the vehicle speed VS becomes equal to or less than the second vehicle speed determination value VSth2 after being greater than the second vehicle speed determination value VSth2.

[0068] The second vehicle body speed determination value VSth2 may be set based on the maintained braking force BPh that is set through the execution of the series of processes shown in Fig. 3. In this case, the second vehicle body speed determination value VSth2 becomes smaller as the maintained braking force BPh increases.

[0069] If the processing circuit 51 determines that the transition condition is not met (S57: NO), the processing circuit 51 proceeds to step S55. That is, the processing circuit 51 executes the increase correction process. On the other hand, if the processing circuit 51 determines that the transition condition is met (S57: YES), the processing circuit 51 proceeds to step S59.

[0070] In step S59, the processing circuit 51 executes the decrease process of the decrease correction process. In the decrease process, the processing circuit 51 decreases the command braking force BPTr to the held braking force BPh. Then, the processing circuit 51 operates the brake actuator 30 based on the command braking force BPTr.

[0071] In the following step S61, the processing circuit 51 determines whether the command braking force BPTr has become equal to or less than the held braking force BPh. If the processing circuit 51 determines that the command braking force BPTr is greater than the held braking force BPh (S61: NO), the processing circuit 51 proceeds to step S59. That is, the processing circuit 51 executes a reduction process. On the other hand, if the processing circuit 51 determines that the command braking force BPTr has become equal to or less than the held braking force BPh (S61: YES), the processing circuit 51 proceeds to step S63.

[0072] In step S63, the processing circuit 51 executes a holding process of the reduction correction process. In the holding process, the processing circuit 51 holds the command braking force BPTr at the held braking force BPh. Then, the processing circuit 51 operates the brake actuator 30 based on the command braking force BPTr.

[0073] In the next step S65, the processing circuit 51 determines whether or not a transition condition from the reduction correction processing to the degeneration processing is satisfied. For example, as shown in FIG. 2, the processing circuit 51 determines that the transition condition is satisfied when it is determined that the vehicle 10 has stopped. If the processing circuit 51 determines that the transition condition is not satisfied (S65: NO), the processing circuit 51 transitions the processing to step S63. That is, the processing circuit 51 executes the holding processing. On the other hand, if the processing circuit 51 determines that the transition condition is satisfied (S65: YES), the processing circuit 51 transitions the processing to step S67.

[0074] In step S67, the processing circuit 51 executes a degeneration process. In the degeneration process, the processing circuit 51 increases the command braking force BPTr to the required braking force BPRq. Then, the processing circuit 51 operates the brake actuator 30 based on the command braking force BPTr.

[0075] In the following step S69, the processing circuit 51 determines whether or not the termination condition for the degeneration processing is satisfied. For example, if the command braking force BPTr is equal to the required braking force BPRq, the termination condition is deemed to be satisfied. On the other hand, if the command braking force BPTr is less than the required braking force BPRq, the termination condition is deemed not to be satisfied. If the processing circuit 51 determines that the termination condition is not satisfied (S69: NO), the processing circuit 51 proceeds to step S67. That is, the processing circuit 51 executes the degeneration processing. On the other hand, if the processing circuit 51 determines that the termination condition is satisfied (S69: YES), the processing circuit 51 terminates the degeneration processing. Then, the processing circuit 51 terminates the stationary braking control and ends the series of processing shown in FIG. 4.

[0076] In this embodiment, the process of step S53 is executed by the processing circuit 51 functioning as the control unit M21. <Actions and Effects of This Embodiment> With reference to FIG. 5, the operation and effect when a braking force is applied to the vehicle 10 in a situation where a stopping position guide exists in the traveling direction of the vehicle 10 will be described.

[0077] As shown in (A), (B), and (C) of FIG. 5, when a braking force is applied to the vehicle 10, the vehicle speed VS decreases. During such vehicle braking and before the start of the stop-time braking control, the processing circuit 51 sets a maintaining braking force BPh based on the distance DIS between the vehicle 10 and the stop position indicated by the stop position guide. In the example shown in FIG. 5, the processing circuit 51 sets a vehicle braking force that is greater than the stop-maintaining braking force BPth as the maintaining braking force BPh. Specifically, the shorter the distance DIS obtained before the start of the stop-time braking control, the greater the vehicle braking force that the processing circuit 51 sets as the maintaining braking force BPh.

[0078] When the vehicle body speed VS reaches the first vehicle body speed determination value VSth1 at timing t21, the processing circuit 51 starts stationary braking control. That is, the processing circuit 51 starts an increasing correction process for the stationary braking control. In the increasing correction process, the processing circuit 51 sets the sum of the required braking force BPRq and the offset value ΔBP as the command braking force BPTr. Then, the processing circuit 51 controls the brake actuator 30 so that the vehicle braking force BPAl becomes the command braking force BPTr. As a result, as shown in FIGS. 5A and 5C, the vehicle braking force BPAl is increased even though the required braking force BPRq is constant. Specifically, the vehicle braking force BPAl becomes larger than the required braking force BPRq. As a result, the absolute value of the longitudinal acceleration Gx increases, as shown in FIG. 5B.

[0079] When the vehicle speed VS reaches the second vehicle speed determination value VSth2 at timing t22, the processing circuit 51 shifts the processing from the increasing correction processing to the decreasing correction processing. Specifically, the processing circuit 51 starts the decreasing correction processing of the decreasing correction processing. In the decreasing processing, the processing circuit 51 decreases the command braking force BPTr toward the held braking force BPh. Then, the processing circuit 51 controls the brake actuator 30 so that the vehicle braking force BPAl becomes the command braking force BPTr. As a result, the vehicle braking force BPAl becomes smaller than the required braking force BPRq. As a result, even if the required braking force BPRq remains the same, the absolute value of the longitudinal acceleration Gx of the vehicle 10 gradually decreases.

[0080] When the command braking force BPTr becomes equal to the held braking force BPh at timing t23 during the reduction process, the processing circuit 51 starts the holding process of the reduction correction process. In the holding process, the processing circuit 51 holds the command braking force BPTr at the held braking force BPh. Then, the processing circuit 51 controls the brake actuator 30 so that the vehicle braking force BPAl is held.

[0081] If it is determined that the vehicle 10 has stopped at timing t24 while the holding process is being executed, the processing circuit 51 transitions from the reduction correction process to the degeneration process. In the degeneration process, the processing circuit 51 increases the command braking force BPTr to the required braking force BPRq. Then, the processing circuit 51 operates the brake actuator 30 so that the vehicle braking force BPAl becomes the command braking force BPTr. As a result, the vehicle braking force BPAl is increased to the required braking force BPRq.

[0082] In this embodiment, the absolute value of the longitudinal acceleration Gx immediately before stopping is reduced by performing braking control during stopping. As a result, the fluctuation range of the longitudinal acceleration Gx before and after stopping the vehicle 10 is reduced, and therefore the change in the attitude of the vehicle 10 associated with stopping is reduced. By reducing the change in the attitude of the vehicle 10 associated with stopping, the comfort of the occupants when stopped is increased. However, if the change in the attitude of the vehicle 10 associated with stopping is small, the sense of stopping is reduced. In other words, the greater the change in the attitude of the vehicle 10 associated with stopping, the greater the sense of stopping. When stopping the vehicle 10 in a situation where a stopping position guide is present in the traveling direction of the vehicle 10, the greater the sense of stopping felt by the occupants, the less anxious the occupants will feel.

[0083] Therefore, in this embodiment, the maintained braking force BPh is set based on the distance DIS. Specifically, the shorter the distance DIS, the larger the maintained braking force BPh. By performing such stationary braking control based on the maintained braking force BPh, the fluctuation range of the longitudinal acceleration Gx before and after the vehicle stops becomes larger compared to when stationary braking control is performed in which the stationary maintenance braking force BPth is set as the maintained braking force BPh. In other words, the degree to which changes in the posture of the vehicle 10 are suppressed by performing stationary braking control becomes smaller, which makes the vehicle feel more likely to stop.

[0084] However, because the braking control during vehicle stop is performed, the maintained braking force BPh is smaller than the required braking force BPRq. Therefore, the fluctuation range of the longitudinal acceleration Gx before and after the vehicle stops is smaller than when the braking control during vehicle stop is not performed. In other words, passenger comfort while the vehicle is stopped is higher than when the braking control during vehicle stop is not performed.

[0085] Therefore, when braking control is performed when the vehicle 10 is stopped and a stopping position guide is present in the direction of travel of the vehicle 10, the braking control device 50 can simultaneously provide the occupants with a sense of stopping and improve the comfort of the occupants when the vehicle is stopped.

[0086] In this embodiment, the following effects can be further obtained. (1) The processing circuit 51 increases the maintained braking force BPh as the distance DIS acquired before the start of the vehicle stop braking control decreases. As a result, the processing circuit 51 can provide the occupants with a greater sense of stopping when stopping the vehicle 10 as the distance DIS between the vehicle 10 and the stop position guide decreases. On the other hand, when the distance DIS between the vehicle 10 and the stop position indicated by the stop position guide is relatively long, the processing circuit 51 does not increase the maintained braking force BPh, thereby reducing the sense of stopping that the occupants feel when stopping the vehicle 10, thereby improving the comfort of the occupants when the vehicle is stopped.

[0087] (2) The vehicle 10 allows the occupant to set the level of comfort when the vehicle is stopped. The processing circuit 51 then reflects the level of comfort set by the occupant in the setting of the holding braking force BPh. Therefore, the processing circuit 51 performs braking control when the vehicle is stopped that reflects the occupant's requests to some extent. Therefore, the braking control device 50 can achieve both a sense of stopping and comfort when the vehicle is stopped in a manner that satisfies the occupant's requests.

[0088] (3) When the required braking force BPRq is large, the driver may desire a greater sense of stopping compared to when the required braking force BPRq is small. Therefore, when the required braking force BPRq is large, the processing circuit 51 increases the maintained braking force BPh compared to when the required braking force BPRq is small. The processing circuit 51 then performs braking control during stopping based on this maintained braking force BPh. Therefore, the brake control device 50 can achieve both a sense of stopping and comfort while the vehicle is stopped in a manner that satisfies the needs of the driver who operates the brake operating member 11.

[0089] (4) When stopping the vehicle 10 in a situation where the stopping position set in accordance with traffic rules exists in the vehicle's direction of travel, it is preferable to stop the vehicle 10 so that the vehicle does not exceed the stopping position. Therefore, when it is predicted that the vehicle will stop beyond the stopping position, the processing circuit 51 increases the holding braking force BPh compared to when it is predicted that the vehicle will be able to stop without exceeding the stopping position. The processing circuit 51 then performs stopping braking control based on this holding braking force BPh. Therefore, when the vehicle stops beyond the stopping position, the brake control device 50 can alert the driver by increasing the feeling of stopping.

[0090] (5) An obstacle present in the traveling direction of the vehicle 10 may be a preceding vehicle. In this case, if the deceleration of the preceding vehicle is smaller than the deceleration of the vehicle 10, the approach speed SPA increases. If the sense of stopping is small when the approach speed SPA is large, the occupants are likely to feel uneasy. Therefore, if the approach speed SPA increases while the vehicle is stationary, the processing circuit 51 corrects the held braking force BPh so that the held braking force BPh increases. When the processing circuit 51 corrects the held braking force BPh in this way, the processing circuit 51 performs the vehicle stationary braking control based on the corrected held braking force BPh. As a result, the brake control device 50 can make the occupants less likely to feel uneasy even if the approach speed SPA increases while the vehicle is stationary.

[0091] <Example of change> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0092] The processing circuit 51 does not need to change the degree of suppression of changes in the posture of the vehicle 10 due to the execution of the stationary braking control depending on whether the required braking force BPRq is large or not. In other words, the processing of step S17 may be omitted from the series of processing shown in FIG.

[0093] The processing circuit 51 does not need to change the degree of suppression of changes in the attitude of the vehicle 10 due to the execution of the stop-time braking control depending on whether it is predicted that the vehicle 10 will stop beyond the stop position. In other words, the processing of steps S25 and S27 may be omitted from the series of processing shown in FIG.

[0094] The operation unit for setting the level of comfort when the vehicle is stopped does not have to be an in-vehicle user interface. For example, an information terminal capable of communicating with the in-vehicle device may function as the operation unit. Such an information terminal may be, for example, a smartphone or tablet terminal owned by the occupant.

[0095] The processing circuit 51 does not need to change the degree of suppression of the change in the posture of the vehicle 10 due to the execution of the stationary braking control depending on the level of comfort required by the occupants. That is, the processing of steps S19 and S21 may be omitted from the series of processing shown in FIG.

[0096] The processing circuit 51 does not need to change the degree of suppression of changes in the posture of the vehicle 10 due to the execution of the stationary braking control in accordance with the approach speed SPA during the execution of the stationary braking control. In other words, the series of processes shown in FIG. 3 may omit the processes from steps S31 to S37.

[0097] The stop position guide may be electronic data such as map information owned by a navigation system or sign information. The stop position guide may also be a travel path generated by automated driving or sign information.

[0098] The processing circuit 51 sets the maintained braking force BPh as the degree of suppression of changes in the posture of the vehicle 10 due to the execution of the stationary braking control. However, the processing circuit 51 may change parameters other than the maintained braking force BPh as long as the degree of suppression can be changed. For example, the processing circuit 51 may change the degree of suppression by changing the rate at which the command braking force BPTr is reduced during the execution of the reduction process. Also, for example, the processing circuit 51 may change the degree of suppression by changing the execution time of the maintenance process. Here, "changing the execution time of the maintenance process" also includes omitting the execution of the maintenance process. Also, for example, the processing circuit 51 may change the degree of suppression by changing the rate at which the command braking force BPTr is increased during the degeneration process.

[0099] When changing a parameter other than the holding braking force BPh, the processing circuit 51 may also change the holding braking force BPh, or may not change the holding braking force BPh. In the above embodiment, the processing circuit 51 determines the start timing of the increase correction process and the start timing of the decrease correction process of the stopping brake control in accordance with changes in the vehicle speed VS. However, the processing circuit 51 may determine the start timing of each process using a parameter other than the vehicle speed VS, as long as the parameter value decreases as the vehicle 10 approaches the predicted stopping position PS. Examples of the other parameters include a stopping distance and a predicted stopping time. The stopping distance is the distance from the current position of the vehicle 10 to the predicted stopping position PS. The predicted stopping time is the time required for the vehicle 10 to stop. An example of the predicted stopping time is TTC, which is an abbreviation for "Time To Collision."

[0100] The braking control when the vehicle is stopped does not need to include an increase correction process as long as it includes a decrease correction process. The reduction correction process does not need to include the retention process as long as it includes the reduction process. When performing braking control at a stop, the braking control device may control not only the friction braking force but also the regenerative braking force. In this case, the vehicle braking force BPAl is the sum of the total friction braking force applied to the vehicle 10 and the total regenerative braking force applied to the vehicle 10.

[0101] In the above embodiment, the processing circuit 51 executes the vehicle-stop braking control when the driver brakes the vehicle in response to the operation of the brake operating member 11. However, the processing circuit 51 may execute the vehicle-stop braking control when automatic braking is performed.

[0102] The processing circuit 51 may perform control other than the above-described vehicle-stop braking control as the vehicle stopping control. For example, the processing circuit 51 may perform control as the vehicle stopping control to adjust the pitch angle of the vehicle 10 during vehicle braking by changing the distribution of braking force applied to the front wheels 12 and braking force applied to the rear wheels 13. In this case, the processing circuit 51 can suppress changes in the posture of the vehicle 10 that occur when the vehicle is stopped by increasing the proportion of braking force applied to the rear wheels 13 in the vehicle braking force BPAl.

[0103] The processing circuit 51 may be configured as a circuit including one or more processors operating according to a computer program, one or more dedicated hardware circuits such as dedicated hardware for performing at least some of the various processes, or a combination thereof. Examples of dedicated hardware include an application-specific integrated circuit (ASIC). The processor includes a CPU and memory such as RAM and ROM, which stores program code or instructions configured to cause the CPU to perform processes. The memory, i.e., storage medium, includes any available medium accessible by a general-purpose or dedicated computer.

[0104] <Other technical ideas> The technical concepts that can be understood from the above-described embodiments and modifications will be described below. [Supplementary Note 1] The stopping control is preferably a control that reduces the braking force to a value smaller than the required value of the braking force and sets the vehicle speed of the vehicle to 0 (zero).

[0105] [Appendix 2] The stopping position guide includes an obstacle that may hinder the travel of the vehicle, It is preferable that the position acquisition unit acquires, as the stopping position, a position in front of the obstacle that exists in the traveling direction of the vehicle.

[0106] [Appendix 3] The stopping position guide includes a road sign, It is preferable that the position acquisition unit acquires the stopping position defined by a road sign present in the traveling direction of the vehicle.

[0107] [Appendix 4] When stopping the vehicle at a stopping position defined by a road sign, if it is predicted that the vehicle will stop beyond the stopping position, it is preferable that the setting unit reduces the degree of suppression compared to when it is predicted that the vehicle will stop without exceeding the stopping position.

[0108] [Supplementary Note 5] When the required value of the braking force is large, the setting unit preferably reduces the suppression degree compared to when the required value is small. The expression "at least one" used herein means "one or more" of the desired options. As an example, the expression "at least one" used herein means "only one option" or "both of two options" if the number of options is two. As another example, the expression "at least one" used herein means "only one option" or "any combination of two or more options" if the number of options is three or more. [Explanation of symbols]

[0109] 10...Vehicle 12,13...Wheel 30...Braking actuator 50...Brake control device 51...Processing circuit 70...Operation unit M10…Position acquisition unit M11...Distance acquisition section M13…Approach speed acquisition part M15…Operation information acquisition unit M19…Setting section M21...Control section

Claims

1. A braking control device that performs stopping control to control braking force to suppress a change in posture of a vehicle caused by stopping the vehicle when braking force is applied to the vehicle, a position acquisition unit that acquires a stop position indicated by a stop position guide at which the vehicle should be stopped; a distance acquisition unit that acquires a distance between the stopping position and the vehicle; a setting unit that sets a degree of suppression of a change in the attitude of the vehicle due to execution of the stopping control based on the distance acquired by the distance acquisition unit; A braking control device comprising:

2. The setting unit reduces the suppression degree as the distance acquired by the distance acquisition unit becomes shorter. The braking control device according to claim 1.

3. an approach speed acquisition unit that acquires an approach speed between the vehicle and the stop position guide when the stop control is being performed; The setting unit sets the suppression degree so that the suppression degree decreases as the approach speed acquired by the approach speed acquisition unit during execution of the vehicle stop control increases. The braking control device according to claim 2.

4. an operation information acquisition unit that acquires comfort information related to comfort when the vehicle is stopped, the comfort information being set by an operation of the operation unit by an occupant of the vehicle; The setting unit sets the suppression degree in consideration of the comfort information acquired by the operation information acquisition unit. The braking control device according to any one of claims 1 to 3.

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