Brake control device for a vehicle

Abstract

The brake control device (40) according to the present application includes a control unit (41) that controls a braking force in accordance with an operation amount of a brake operation member (15), and a brake determination unit (42) that determines whether or not a reduction in the operation amount of the brake operation member (15) has started in a case where the braking force is applied to a vehicle (10) by operating the brake operation member (15). The control unit (41) starts a restriction process that sets a limit to a reduction speed of the braking force of the vehicle (10) in a case where the reduction speed of the operation amount when it is determined that the reduction in the operation amount has started is equal to or higher than a reduction speed determination value.

Description

Technical Field

[0001] This invention relates to a braking control device for vehicles. Background Technology

[0002] Patent Document 1 describes an example of vehicle acceleration / deceleration control when the vehicle is driving automatically. Specifically, when a vehicle is accelerating and deceleration is requested, a predetermined interval is set between the request for deceleration and the commencement of deceleration. This allows the vehicle's movement from an automatically accelerating state to a decelerating state to its movement closely approximating the movement of the vehicle when manually operated by the driver.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2017-121851

[0004] When a vehicle decelerates due to the driver's operation of the braking system, if the driver releases the braking system, no braking force is applied to the vehicle, causing a change in the vehicle's pitch angle. If the rate of change in pitch angle is large, passengers in the vehicle may experience discomfort. Summary of the Invention

[0005] A braking control device for a vehicle designed to solve the aforementioned problems is a device that controls the braking force of a vehicle by activating a braking device. This braking control device includes: a control unit that controls the braking force of the vehicle based on the amount of operation of a braking operating component; and a braking determination unit that, when braking force is applied to the vehicle by operating the braking operating component, determines whether a reduction in the amount of operation has begun. If, when it is determined that a reduction in the amount of operation has begun, the rate of reduction of the amount of operation is greater than or equal to a rate of reduction determination value, the control unit initiates a limitation process that sets a limit on the rate of reduction of the vehicle's braking force.

[0006] When braking force is applied to a vehicle through the driver's operation of the braking control components, reducing the amount of operation of the braking control components reduces the braking force. If the braking force decreases, the vehicle's pitch angle changes. Based on this configuration, if the rate of decrease in the amount of operation is determined to have begun and exceeds a predetermined rate of decrease, a limiting process is executed. In this limiting process, a limit is set on the rate of decrease in braking force. Therefore, during the execution of the limiting process, although the braking force decreases, the rate of decrease in braking force is not too large. As a result, although the pitch angle changes according to the decrease in braking force, an increase in the rate of change of the pitch angle is suppressed.

[0007] Furthermore, if the rate of decrease in the control amount when it is determined that a reduction in the control amount has begun is less than the rate of decrease determination value, even if the braking force is reduced at a rate corresponding to the rate of decrease in the control amount, the rate of decrease in the braking force itself is not large. Therefore, even if the pitch angle changes according to the reduction in the braking force, the rate of change of the pitch angle will not be large.

[0008] Therefore, based on the above configuration, when the driver reduces the amount of operation of the braking components, it is possible to suppress discomfort felt by passengers. Attached Figure Description

[0009] Figure 1 This is a schematic diagram showing the functional configuration of the braking control device of the vehicle in the first embodiment and the vehicle using the braking control device.

[0010] Figure 2 This is a flowchart illustrating the processing routines executed by the braking control device.

[0011] Figure 3 (a) and (b) are timing diagrams of the driver releasing the braking control components.

[0012] Figure 4 (a) and (b) are timing diagrams of the driver releasing the operation of the brake control component in the brake control device of the second embodiment.

[0013] Figure 5 This is a mapping diagram showing the relationship between the reduced speed indication value and the vehicle's forward and backward acceleration in the braking control device of the third embodiment.

[0014] Figure 6 (a) and (b) are timing diagrams of the driver releasing the operation of the brake control component in the brake control device of the third embodiment.

[0015] Figure 7 This is a flowchart illustrating a part of the processing routine executed by the braking control device according to the fourth embodiment.

[0016] Figure 8 (a) and (b) are timing diagrams of the driver releasing the operation of the brake operation component in the brake control device of the fourth embodiment.

[0017] Figure 9 (a) to (d) are timing diagrams of the driver releasing the operation of the brake control component in the brake control device of the fifth embodiment.

[0018] Figure 10 This is a schematic diagram showing the positional relationship between the head of a passenger in the vehicle and the headrest in this braking control device.

[0019] Figure 11 This is a schematic diagram showing the positional relationship between the passenger's head and the headrest in the braking control device.

[0020] Figure 12 This is a schematic diagram showing the positional relationship between the passenger's head and the headrest in the braking control device.

[0021] Figure 13 This is a schematic diagram showing the positional relationship between the passenger's head and the headrest in the braking control device. Detailed Implementation

[0022] (First Implementation)

[0023] The following is based on Figures 1-3 A first embodiment of the vehicle braking control device will be described.

[0024] <Overall Composition>

[0025] exist Figure 1 The diagram schematically illustrates a portion of a vehicle 10 equipped with the brake control device 40 of this embodiment. The vehicle 10 includes a brake device 20 controlled by the brake control device 40 and a number of brake mechanisms 12 equal to the number of wheels 11. Each brake mechanism 12 operates to generate braking force on its corresponding wheel 11. Each brake mechanism 12 includes a wheel cylinder 121, a rotating body 122 that rotates integrally with the wheel 11, and a friction material 123. The higher the hydraulic pressure within the wheel cylinder 121, i.e., the higher the wheel pressure, the greater the force that presses the friction material 123 against the rotating body 122, i.e., the pressing force. Furthermore, the greater the pressing force, the greater the braking force generated on the wheel 11.

[0026] The braking device 20 controls the braking force generated at each wheel 11 by adjusting the wheel pressure of each wheel cylinder 121. That is, the braking device 20 adjusts the braking force BP of the vehicle 10 by controlling the braking force generated at each wheel 11. Furthermore, the sum of the braking forces generated at each wheel 11 is the braking force BP of the vehicle 10.

[0027] When the driver of the vehicle 10 operates the brake operating component 15, the braking device 20 operates according to the instruction from the brake control device 40. The brake operating component 15 can be, for example, the brake pedal. When the brake control device 40 instructs an increase in braking force BP, such as when the amount of operation of the brake operating component 15 increases, the braking device 20 operates to increase the wheel pressure of each wheel cylinder 121. On the other hand, when the brake control device 40 instructs a decrease in braking force BP, such as when the amount of operation of the brake operating component 15 decreases, the braking device 20 operates to decrease the wheel pressure of each wheel cylinder 121.

[0028] Furthermore, "driver" refers to the passenger sitting in the driver's seat. Passengers sitting in seats other than the driver's seat are referred to as passengers. Seats other than the driver's seat include, for example, the front passenger seat and rear seats.

[0029] A brake light 18 is provided at the rear of the vehicle body in vehicle 10. The brake light 18 is controlled by brake control device 40. For example, when braking force BP is applied to vehicle 10, brake light 18 is illuminated. On the other hand, when braking force BP is not applied to vehicle 10, brake light 18 is extinguished.

[0030] <Vehicle 10 Detection System>

[0031] Vehicle 10 is equipped with various sensors. Examples of such sensors include wheel speed sensor 31, brake operation amount sensor 32, steering angle sensor 33, front and rear acceleration sensors 34, and lateral acceleration sensor 35. Each of these sensors 31 to 35 outputs a signal corresponding to the detection result to the brake control device 40 as a detection signal.

[0032] The vehicle 10 is equipped with wheel speed sensors 31, the same number as the wheels 11. The wheel speed sensors 31 detect the rotational speed of the corresponding wheel 11, i.e., the wheel speed VW. The brake operation amount sensor 32 detects the amount X of the driver's operation on the brake operation component 15. The steering angle sensor 33 detects the steering angle STR of the steering wheel 16 operated by the driver. The front and rear acceleration sensors 34 detect the front and rear acceleration Gx of the vehicle 10. The lateral acceleration sensor 35 detects the lateral acceleration Gy of the vehicle 10.

[0033] Vehicle 10 has a monitoring system 50 that monitors the surroundings of vehicle 10. The monitoring system 50 includes a camera and other imaging units, as well as radar and other devices. The monitoring system 50 monitors, for example, the positions of other vehicles, pedestrians, and traffic lights around vehicle 10. The monitoring system 50 outputs information related to the monitoring results to the braking control device 40.

[0034] <Brake control device 40>

[0035] The braking control device 40 includes a CPU and a storage device. The storage device stores programs executed by the CPU. That is, by executing the programs by the CPU, the braking control device 40 can perform various braking-related processes.

[0036] The braking control device 40 has a control unit 41 and a braking determination unit 42 as functional units.

[0037] The control unit 41 controls the braking force BP of the vehicle 10 based on the operation amount X of the braking operation component 15. For example, the larger the operation amount X, the larger the value derived by the control unit 41 as the required braking force BPr. The required braking force BPr refers to the required value of the braking force BP. Based on the required braking force BPr, the control unit 41 derives an indicated value of the braking force BP, namely the indicated braking force BPTr. Then, based on the indicated braking force BPTr, the control unit 41 activates the braking device 20. Thus, when the operation amount X increases, the braking force BP can be increased. When the operation amount X decreases, the braking force BP can be decreased.

[0038] When the braking determination unit 42 applies braking force BP to the vehicle 10 by operating the braking operation component 15, it determines whether the reduction of the operation amount X has begun.

[0039] The brake control device 40 includes a steering operation determination unit 43. The steering operation determination unit 43 determines whether the driver has begun operating the steering wheel 16, i.e., steering operation. Additionally, the steering operation determination unit 43 can also determine whether steering operation can be predicted. Furthermore, in this embodiment, the brake control device 40 may not include a steering operation determination unit 43.

[0040] <Flowchart of processing performed by brake control device 40 when the driver releases the brake operation component 15>

[0041] Reference Figure 2 The processing routine executed by the brake control device 40 when the operation of the brake operating component 15 is released will be described. The brake control device 40 repeatedly executes this processing routine when the vehicle 10 is given a braking force BP due to the driver's operation of the brake operating component 15.

[0042] In this processing routine, in the initial step S11, the brake control device 40 acquires the operation amount X of the brake operating component 15. In the next step S13, the brake control device 40 derives the required braking force BPr based on the operation amount X.

[0043] Next, in step S15, the braking control device 40 calculates the reduction rate ΔX of the operation amount X. For example, the braking control device 40 calculates the product of the time derivative of the operation amount X and "-1" as the reduction rate ΔX. In this case, a negative value is calculated as the reduction rate ΔX when the operation amount X increases. On the other hand, a positive value is calculated as the reduction rate ΔX when the operation amount X decreases.

[0044] In the next step S17, the brake determination unit 42 of the brake control device 40 determines whether the reduction speed ΔX is greater than or equal to a first determined reduction speed ΔXth1. The first determined reduction speed ΔXth1 is a reference for determining whether the operation amount X has decreased based on the reduction speed ΔX. For example, a positive value is set as the first determined reduction speed ΔXth1. If the reduction speed ΔX is greater than or equal to the first determined reduction speed ΔXth1, it is considered that the operation amount X has decreased due to the driver's operation of the brake operation component 15. On the other hand, if the reduction speed ΔX is less than the first determined reduction speed ΔXth1, it is not considered that the operation amount X has decreased.

[0045] If the reduction speed ΔX is less than the first determined reduction speed ΔXth1 (S17: No), the brake control device 40 temporarily terminates this processing routine. In this case, the control unit 41 of the brake control device 40 sets a value equal to the required braking force BPr as the indicated braking force BPTr, and activates the brake device 20 based on the indicated braking force BPTr.

[0046] On the other hand, if in step S17 the reduction speed ΔX is greater than or equal to the first determined reduction speed ΔXth1, the brake control device 40 moves the processing to step S19. In step S19, the brake control device 40 determines whether the reduction speed ΔX is greater than or equal to the second determined reduction speed ΔXth2. The second determined reduction speed ΔXth2 is a reference for determining whether the driver operates the brake operating component 15 in a manner that gradually reduces the speed by an operation amount X. The second determined reduction speed ΔXth2 is set to a value larger than the first determined reduction speed ΔXth1. If the reduction speed ΔX is smaller than the second determined reduction speed ΔXth2, it is considered that the driver operates the brake operating component 15 in a manner that gradually reduces the speed by an operation amount X. On the other hand, if the reduction speed ΔX is greater than or equal to the second determined reduction speed ΔXth2, it is not considered that the driver operates the brake operating component 15 in a manner that gradually reduces the speed by an operation amount X. That is, the second determined reduction speed ΔXth2 corresponds to the "reduction speed determination value". Therefore, in step S19, it can be said that it is determined whether the rate of decrease of the operation quantity X when it is determined that the decrease of the operation quantity X has started is above the decrease rate determination value.

[0047] In step S19, if the reduction speed ΔX is less than the second determined reduction speed ΔXth2 (No), the brake control device 40 temporarily terminates the current processing routine. In this case, the brake control device 40 sets a value equal to the required braking force BPr as the indicated braking force BPTr, and operates the brake device 20 based on the indicated braking force BPTr.

[0048] On the other hand, in step S19, if the reduction speed ΔX is greater than or equal to the second determined reduction speed ΔXth2, the control unit 41 of the brake control device 40 performs a restriction process that limits the reduction speed of the braking force BP. That is, the control unit 41 starts the restriction process when it determines that the reduction speed of the operation amount X when the reduction of the operation amount X has started is greater than or equal to the reduction speed determination value.

[0049] In the limiting process, in step S21, the control unit 41 performs a process of deriving an indication value for the reduction speed of the braking force BP, i.e., a reduction speed indication value dBP. Here, in order to reduce the braking force BP, a positive value is derived as the reduction speed indication value dBP. In this embodiment, the control unit 41 sets a limiting reduction speed dBPL as the reduction speed indication value dBP. For example, the limiting reduction speed dBPL is set as the reduction speed of the required braking force BPr when the reduction speed ΔX of the operation amount X is equal to the second determination reduction speed ΔXth2. If the reduction speed indication value dBP is derived, the control unit 41 moves the process to step S23.

[0050] In step S23, the control unit 41 performs an operation process to activate the braking device 20. Specifically, the control unit 41 calculates the product of the reduced speed indication value dBP and the cycle time as the indicated reduction amount ΔBP. The cycle time refers to the time corresponding to the execution interval of the operation process when the operation process is repeatedly executed during the execution of the restriction process. The control unit 41 calculates the latest indicated braking force BPTr as the value obtained by subtracting the indicated reduction amount ΔBP from the previous value BTr1 of the indicated braking force BPTr. The previous value BTr1 of the indicated braking force refers to the indicated braking force BPTr calculated during the last execution of the operation process in step S23. When step S23 is executed for the first time after it is determined that the reduction of the operation amount X has begun, the braking force BP at that moment is set as the previous value BTr1 of the indicated braking force. Therefore, the indicated braking force BPTr can be reduced at a speed corresponding to the reduced speed indication value dBP.

[0051] Next, during operation processing, the control unit 41 activates the braking device 20 based on the indicated braking force BPTr. In this embodiment, steps S21 and S23 correspond to the "limiting process". If the control unit 41 activates the braking device 20 by executing the limiting process, the brake control device 40 moves the processing to step S25.

[0052] In step S25, the brake control device 40 acquires the indicated braking force BPTr. In the next step S27, the brake control device 40 determines whether the indicated braking force BPTr acquired in step S25 is below the release determination value BPth. The release determination value BPth is a reference used to determine whether to still apply braking force BP to the vehicle 10. For example, 0 is set as the release determination value BPth. If the indicated braking force BPTr is below the release determination value BPth, it is considered that no braking force BP is applied to the vehicle 10. On the other hand, if the indicated braking force BPTr is greater than the release determination value BPth, it is considered that braking force BP is still applied to the vehicle 10.

[0053] In step S27, if the indicated braking force BPTr is greater than the release determination value BPth (No), the brake control device 40 moves the process to step S21. That is, the control unit 41 of the brake control device 40 continues the restriction process. On the other hand, if in step S27 the indicated braking force BPTr is less than or equal to the release determination value BPth (Yes), the brake control device 40 moves the process to step S29. That is, the control unit 41 ends the restriction process. Furthermore, in step S29, the brake control device 40 turns off the brake lamp 18. Thereafter, the brake control device 40 temporarily terminates this processing routine.

[0054] <Function and Effects of This Embodiment>

[0055] exist Figure 3 This shows the shift in the amount of operation X and the shift in the forward and backward acceleration Gx when the driver releases the operation of the brake control component 15.

[0056] like Figure 3 As shown in (a) and (b), when the driver operates the brake operating component 15, the larger the operation amount X, the greater the braking force BP of the vehicle 10, and therefore the smaller the front-to-rear acceleration Gx of the vehicle 10. The operation amount X begins to decrease from time t11. Thus, at time t12, it is determined that the decrease in the operation amount X has begun.

[0057] Furthermore, during the period from time t11 to time t12, the braking force BP decreases at a rate corresponding to the rate of decrease of the operating quantity X. That is, even if the operating quantity X begins to decrease, the braking force BP decreases at the rate required to decrease the braking force BPR during the period until it is determined that the decrease of the operating quantity X has begun.

[0058] exist Figure 3 In (b), the change in forward and backward acceleration Gx without the limiting process is shown by a dashed line. That is, it can also be said that the change in the required braking force Bpr is shown by a dashed line. On the other hand, the change in forward and backward acceleration Gx in this embodiment with the limiting process is shown by a solid line.

[0059] If the rate of decrease of the operational quantity ΔX at time t12 is greater than or equal to the second determination rate of decrease ΔXth2, then a restriction process is initiated. That is, if the rate of decrease of the operational quantity X when it is determined that the decrease has begun is greater than or equal to the rate of decrease determination value, then a restriction process is initiated. In this restriction process, a restriction is set on the rate of decrease of the braking force BP. Therefore, when the restriction process is executed, the rate of decrease of the braking force BP is smaller compared to the case where the restriction process is not executed. In other words, the restriction referred to here means that although the braking force BP is reduced, the rate of decrease of the braking force BP is suppressed from increasing.

[0060] In this embodiment, the braking force BP is reduced based on the reduction speed indication value dBP. The reduction speed indication value dBP is smaller than the required reduction speed of the braking force BPr. That is, it can be said that the smaller of the limiting reduction speed dBPL and the required reduction speed of the braking force BPr is set as the reduction speed indication value dBP. As a result, compared with the case where no limiting process is performed, the rate of increase of the acceleration Gx before and after acceleration is smaller.

[0061] At time t13, the driver releases the operation of the brake operating component 15. For example, the driver requests that the braking force BPr become 0. However, at time t13, the braking force BP is still applied to the vehicle 10. Therefore, after time t13, the reduction of the braking force BP according to the speed reduction indication value dBP continues. At the subsequent time t14, the driver indicates that the braking force BPTr becomes below the release determination value BPth, and the braking force BP is no longer applied to the vehicle 10. In this way, the restriction process ends. And the brake lights 18 are turned off.

[0062] If the amount of operation X of the braking operating component 15 is reduced, the braking force BP also decreases. If the braking force BP decreases, the inertial force acting on the vehicle body 10 becomes smaller. As a result, the pitch angle of the vehicle body changes. If the rate of change of the pitch angle is large, there is concern that passengers in the vehicle 10 may feel uncomfortable.

[0063] In this embodiment, if the rate of decrease of the braking force BP when the reduction of the operation amount X has begun exceeds the rate of decrease determination value, a limiting process is performed. If the limiting process is performed, although the braking force BP decreases, the rate of decrease of the braking force BP will not be too large. Therefore, the inertial force acting on the vehicle body decreases slowly. As a result, although the pitch angle changes according to the decrease of the braking force BP, the rate of change of the pitch angle can be suppressed from increasing.

[0064] Furthermore, if the rate of decrease in braking force when it is determined that a reduction in the operational amount X has begun is less than the rate of decrease determination value, no restriction processing is performed. That is, the braking force BP decreases at a rate corresponding to the rate of decrease in the operational amount X. In this case, even if the braking force BP decreases at a rate corresponding to the rate of decrease in the operational amount X, the rate of decrease in the braking force BP itself is not large. Therefore, even without restriction processing, the rate of change in the pitch angle is not very large.

[0065] Therefore, in this embodiment, when the driver reduces the amount of operation X of the braking operation component 15, it is possible to suppress discomfort felt by the passenger.

[0066] Here, when increasing the braking force BP, more drivers operate the brake operating component 15 by gradually increasing the operation amount X, considering the comfort of the passengers. However, when decreasing the braking force BP, fewer drivers operate the brake operating component 15 by gradually decreasing the operation amount X, considering the comfort of the passengers.

[0067] In this embodiment, by performing a limiting process when reducing the amount of operation X, the rate of decrease in braking force BP can be suppressed. That is, even for a person who is less aware of the comfort of passengers when reducing braking force BP, such as the driver, the decrease in passenger comfort can be suppressed.

[0068] (Second Implementation)

[0069] according to Figure 4 A second embodiment of the vehicle braking control device will be described. In the following description, the parts that differ from the first embodiment will be described in detail, and the same reference numerals will be used to mark the same or corresponding components as in the first embodiment, and repeated descriptions will be omitted.

[0070] In this embodiment, Figure 2 The processing in step S21 differs from that in the first embodiment. Specifically, in step S21, the smaller the vehicle speed VS of the vehicle 10 when the reduction of the operation amount X of the braking operation component 15 is determined to have begun, the more the control unit 41 reduces the reduction speed indication value dBP of the braking force BP.

[0071] For example, the braking control device 40 derives the vehicle speed VS based on the wheel speed VW of each wheel 11. When the vehicle speed VS at which the reduction of the operation amount X is determined to have begun is set as the vehicle speed VS1 at the start of reduction, the smaller the vehicle speed VS1 at the start of reduction, the smaller the value derived by the control unit 41 as the correction gain α1. In this case, a positive value smaller than 1 is derived as the correction gain α1. The control unit 41 derives the product of the aforementioned limiting reduction speed dBPL and the correction gain α1 as the reduction speed indication value dBP. Therefore, the smaller the vehicle speed VS, the smaller the reduction speed indication value dBP can be.

[0072] If the reduced speed indication value dBP is derived in step S21, the control unit 41 moves the processing to step S23. The content of each process after step S23 is the same as in the first embodiment, so the description is omitted.

[0073] <Function and Effects of This Embodiment>

[0074] like Figure 4 As shown in (a) and (b), if the operation quantity X starts to decrease from time t21, then it is determined at time t22 that the decrease of the operation quantity X has started.

[0075] exist Figure 4 In (b), the change in forward and backward acceleration Gx without the limiting process is shown by dashed lines. On the other hand, the change in forward and backward acceleration Gx in this embodiment with the limiting process is shown by solid lines and dotted lines.

[0076] If the rate of decrease of the operational quantity ΔX at time t22 is greater than or equal to the second determination rate of decrease ΔXth2, then the restriction process is initiated. When the restriction process is executed, the rate of decrease of the braking force BP is smaller compared to the case where the restriction process is not executed.

[0077] In this embodiment, a reduction speed indication value dBP is set based on the vehicle speed VS at time t22, which is also the vehicle speed VS1 at the start of reduction. That is, the smaller the vehicle speed VS1 at the start of reduction, the smaller the resulting value is used as the reduction speed indication value dBP. Therefore, the smaller the vehicle speed VS1 at the start of reduction, the more slowly the braking force BP decreases. Furthermore, in... Figure 4 In (b), the dashed line represents the change in front-to-back acceleration Gx when the initial vehicle speed VS1 is relatively large, and the solid line represents the change in front-to-back acceleration Gx when the initial vehicle speed VS1 is relatively small.

[0078] Here, when the driver releases the brake operation component 15 at a relatively high vehicle speed VS, if the change in front-to-back acceleration corresponding to the decrease in speed of the operation amount X differs significantly from the actual change in front-to-back acceleration Gx, the driver may feel that the vehicle's movement is incongruous.

[0079] In this respect, in this embodiment, when the driver releases the brake operating component 15 at a relatively high vehicle speed VS, the rate of reduction of the braking force BP is prevented from being too small. Therefore, even with the limitation measures implemented, the discrepancy between the change in front-rear acceleration corresponding to the rate of reduction of the operating amount X and the actual change in front-rear acceleration Gx is not easily amplified. Thus, when the driver reduces the operating amount X of the brake operating component 15, it is possible to minimize discomfort for passengers and reduce the driver's perception of incongruity with the vehicle's movements.

[0080] On the other hand, when the vehicle speed VS is relatively low, such as when the vehicle 10 is stationary, and the operation of the brake operating component 15 is released, the braking force BP decreases slowly. As a result, the change in pitch angle is slower when the operation of the brake operating component 15 is released. Therefore, the decrease in passenger comfort when the driver's operation amount X of the brake operating component 15 decreases can be further suppressed.

[0081] In addition, Figure 4 In the example shown, the driver's brake operation component 15 is released at time t23. At time t23, the indicated braking force BPTr is greater than the release determination value BPth, so braking force BP is still applied to vehicle 10. Therefore, the braking process continues after time t23.

[0082] (Third Implementation)

[0083] according to Figure 5 as well as Figure 6 A third embodiment of the vehicle braking control device will be described. In the following description, the parts that differ from the embodiments described above will be mainly described, and the same reference numerals will be used for components that are the same as or corresponding to those in the embodiments described above, and repeated descriptions will be omitted.

[0084] In this embodiment, Figure 2 The processing in step S21 differs from that in the embodiments described above. Specifically, in step S21, the greater the forward and backward acceleration Gx, the more the control unit 41 reduces the reduction speed indication value dBP of the braking force BP.

[0085] For example, control unit 41 uses Figure 5The mapping diagram shown derives the deceleration indication value dBP. This mapping diagram represents the relationship between the forward and backward acceleration Gx and the deceleration indication value dBP. In the mapping diagram, when the forward and backward acceleration Gx is negative, the larger the absolute value of the forward and backward acceleration Gx, the larger the deceleration indication value dBP. However, it is preferable to keep the upper limit of the deceleration indication value dBP below the aforementioned limit of deceleration dBPL.

[0086] If a reduced speed indication value dBP is derived in step S21, the control unit 41 moves the processing to step S23. Then, in step S23, the control unit 41 performs operation processing. If, in the subsequent step S27, the indicated braking force BPTr is greater than the release determination value BPth (no), the control unit 41 continues the restriction processing. In this embodiment, if the acceleration Gx changes due to the reduction of the operation amount X, the reduced speed indication value dBP derived in step S21 changes. In other words, during the execution of the restriction processing, the reduced speed indication value dBP decreases.

[0087] <Function and Effects of This Embodiment>

[0088] like Figure 6 As shown in (a) and (b), if the operation quantity X starts to decrease from time t31, then it is determined at time t32 that the decrease of the operation quantity X has started.

[0089] exist Figure 6 In (b), the change in forward and backward acceleration Gx without the limiting process is shown by a dashed line. On the other hand, the change in forward and backward acceleration Gx in this embodiment with the limiting process is shown by a solid line.

[0090] If the rate of decrease of the operational quantity ΔX at time t32 is greater than or equal to the second determination rate of decrease ΔXth2, then the restriction process is initiated. When the restriction process is executed, the rate of decrease of the braking force BP is smaller compared to the case where the restriction process is not executed.

[0091] Initially, after the initial braking process, the absolute value of the forward and backward acceleration Gx is relatively large. Therefore, a relatively large value is set as the reduction speed indication value dBP. As a result, the braking force BP decreases at a relatively large rate. However, as the absolute value of the forward and backward acceleration Gx approaches zero due to the decrease in the operational amount X, the reduction speed indication value dBP decreases. Therefore, the braking force BP gradually decreases in rate.

[0092] Furthermore, even if the driver releases the brake operation component 15 at time t33, the indicated braking force BPTr is greater than the release determination value BPth, and braking force BP is still applied to the vehicle 10. Therefore, the restriction process continues after time t33. That is, after time t33, the rate of decrease of braking force BP also changes according to the change in acceleration Gx.

[0093] Here, when the driver reduces the amount of operation X while the front-rear acceleration Gx is relatively small, if the change in front-rear acceleration corresponding to the change in operation X differs significantly from the actual change in front-rear acceleration Gx, the driver may feel that the vehicle's behavior is incongruous.

[0094] In this respect, in this embodiment, when the operating amount X is reduced while the front-rear acceleration Gx is relatively small, even with the implementation of limiting measures, the rate of reduction of the braking force BP can be suppressed from being too small. That is, even with the implementation of limiting measures, the discrepancy between the change in front-rear acceleration corresponding to the change in operating amount X and the actual change in front-rear acceleration Gx is not likely to increase. Therefore, it is possible to suppress the driver's feeling of unease with the vehicle's movement when the operating amount X is reduced.

[0095] If the aft-rear acceleration Gx increases due to the reduction in the amount of braking X, the braking force BP decreases slowly. This reduces the rate of change in the vehicle's pitch angle. Consequently, it further suppresses the decrease in passenger comfort when the amount of braking X is reduced by the driver's operation of the braking control component 15.

[0096] (Fourth Implementation)

[0097] according to Figure 7 as well as Figure 8 A fourth embodiment of the vehicle braking control device will be described. In the following description, the parts that differ from the embodiments described above will be mainly described, and the same reference numerals will be used to mark the same or corresponding components as in the embodiments described above, and repeated descriptions will be omitted.

[0098] <Flowchart of the brake control device 40 when the driver releases the brake operation component 15>

[0099] exist Figure 7 The diagram illustrates a part of the processing routine executed by the brake control device 40 when the operation of the brake operation component 15 is released.

[0100] In this processing routine, the braking control device 40 performs... Figure 2 Each of the processes in steps S11 to S19 shown above. In step S19, if the reduction speed ΔX is greater than or equal to the second determined reduction speed ΔXth2, the control unit 41 of the braking control device 40 performs a limiting process.

[0101] In the restriction process, in step S21, the control unit 41 performs the process of deriving the reduced speed indication value dBP. Next, in step S23, the control unit 41 performs the operation process. If the control unit 41 causes the braking device 20 to operate through the execution of the restriction process, the control unit 41 moves the process to step S231.

[0102] In step S231, the control unit 41 acquires the operation quantity X. In the next step S233, the control unit 41 determines whether the operation quantity X acquired in step S233 is less than or equal to the determination operation quantity Xth. The determination operation quantity Xth is a reference used to determine whether the driver's operation on the brake operation component 15 has been released. For example, 0 can be set as the determination operation quantity Xth. If the operation quantity X is less than or equal to the determination operation quantity Xth, the operation is considered to have been released. On the other hand, if the operation quantity X is greater than the determination operation quantity Xth, the operation is not considered to have been released.

[0103] If the operation amount X is greater than the determination operation amount Xth (S233: No), the control unit 41 moves the processing to step S21. That is, the control unit 41 continues the restriction processing. On the other hand, if the operation amount X is less than or equal to the determination operation amount Xth (S233: Yes), the control unit 41 moves the processing to step S235. That is, the control unit 41 ends the restriction processing.

[0104] In step S235, the control unit 41 performs a reversal process. That is, if the driver releases the operation of the brake operating component 15 during the execution of the restriction process, the control unit 41 ends the restriction process and performs a reversal process. During the reversal process, the control unit 41 increases the rate of reduction of the braking force BP compared to the execution of the restriction process.

[0105] For example, during the rollback process, the control unit 41 activates the braking device 20 such that the braking force BP becomes 0 if a predetermined time TMth elapses from the start of the rollback process. In this case, the control unit 41 derives the value obtained by dividing the indicated braking force BPTr (i.e., the reference braking force BPa) at the start of the rollback process by the predetermined time TMth, as the speed reduction indication value dBP1. Furthermore, the predetermined time TMth is set to a value less than one second. As an example, the predetermined time TMth is 500 milliseconds.

[0106] The control unit 41 calculates the product of the reduced speed indication value dBP1 and the cycle time as the indicated reduction amount ΔBP1. The cycle time refers to the time required from the last execution of step S235 to the current execution of this process. The control unit 41 calculates the value obtained by subtracting the indicated reduction amount ΔBP1 from the indicated braking force BPTr as the latest indicated braking force BPTr. This allows the indicated braking force BPTr to decrease at a speed corresponding to the reduced speed indication value dBP1. Then, the control unit 41 activates the braking device 20 based on the latest indicated braking force BPTr. If the execution of the reversal process controls the braking force BP, the control unit 41 moves the process to step S237.

[0107] In step S237, the control unit 41 determines whether the elapsed time since the start of the rollback process has reached a predetermined time TMth. If the elapsed time has not reached the predetermined time TMth, it is considered that braking force BP is still applied to the vehicle 10. On the other hand, if the elapsed time has reached the predetermined time TMth, it is considered that braking force BP is not applied to the vehicle 10. Therefore, if the elapsed time has not reached the predetermined time TMth (S237: No), the control unit 41 moves the process to step S235. That is, the control unit 41 continues the rollback process. On the other hand, if the elapsed time has reached the predetermined time TMth (S237: Yes), the control unit 41 moves the process to step S29. That is, the control unit 41 ends the rollback process.

[0108] <Function and Effects of This Embodiment>

[0109] like Figure 8 As shown in (a) and (b), if the operation quantity X starts to decrease from time t41, then it is determined at time t42 that the decrease of the operation quantity X has started.

[0110] exist Figure 8 In (b), the shift of forward and backward acceleration Gx without the restriction process is shown by a dashed line. Conversely, the shift of forward and backward acceleration Gx in this embodiment with both restriction and rollback processes is shown by a solid line. Furthermore, the shift of forward and backward acceleration Gx when restriction is performed but rollback is not is shown by a double-dotted line.

[0111] If the rate of decrease of the operational quantity ΔX at time t42 is greater than or equal to the second determination rate of decrease ΔXth2, then a restriction process is initiated. When the restriction process is executed, the rate of decrease of the braking force BP is smaller compared to the case where no restriction process is executed.

[0112] At time t43 during the execution of the restriction process, the operation quantity X becomes less than or equal to the judgment operation quantity Xth, and it is determined that the driver's operation on the brake operation component 15 has been released. In this embodiment, the restriction process ends at time t43, and the rollback process begins. As a result, the rate of decrease in braking force BP is greater than during the execution of the restriction process. That is, at time t44, after a predetermined time TMth has elapsed from time t43, braking force BP is not applied to the vehicle 10. As a result, during the execution of the rollback process, the rate of increase in longitudinal acceleration Gx is greater than during the execution of the restriction process.

[0113] Furthermore, even if it is determined that the driver has released the operation of the brake operation component 15, the processing does not shift from the restriction processing to the reversal processing, and the vehicle 10 is still given braking force BP at time t44.

[0114] If the driver releases the brake operating component 15, the driver may begin to operate the accelerator pedal. If the braking force BP is large at the moment the accelerator pedal is operated, the vehicle 10 will not accelerate easily. In this situation, the driver may feel uneasy about the vehicle's difficult acceleration.

[0115] In this embodiment, if the driver releases the brake operating component 15, the rate of reduction of the braking force BP is increased. As a result, when the driver immediately begins to operate the accelerator pedal after releasing the brake operating component 15, it is less likely that the vehicle 10 will not accelerate smoothly. Therefore, in this embodiment, it is possible to achieve both reduced discomfort for passengers and reduced discomfort for the driver regarding the vehicle's movements.

[0116] (Fifth Implementation)

[0117] according to Figures 9-13 A fifth embodiment of the vehicle braking control device will be described. In the following description, the parts that differ from the embodiments described above will be mainly described, and the same reference numerals will be used to mark the same or corresponding components as in the embodiments described above, and repeated descriptions will be omitted.

[0118] In this embodiment, Figure 2 The processing in step S21 differs from that in the embodiments described above. Specifically, in step S21, the control unit 41 considers the points shown below to derive the reduced speed indication value dBP.

[0119] • Whether the driver has released the operation of the brake control component 15.

[0120] • Whether the steering control determination unit 43 determines that the driver has started steering control.

[0121] For example, the speed reduction indicator value dBP is set as the base speed reduction indicator value dBP11 when the brake operation component 15 is not released and the driver has not been determined to have started steering. If, at this time, the driver is determined to have started steering while the brake operation component 15 is not released, the control unit 41 sets a value smaller than the base speed reduction indicator value dBP11 as the speed reduction indicator value dBP. For example, the control unit 41 sets 0 as the speed reduction indicator value dBP. Subsequently, if the driver releases the brake operation component 15, the control unit 41 gradually increases the speed reduction indicator value dBP.

[0122] When the braking operation component 15 is released and the speed reduction indication value dBP is increased, the control unit 41 can increase the speed reduction indication value dBP by taking into account the front-to-rear acceleration Gx and the lateral acceleration Gy. For example, the control unit 41 derives the total acceleration Gxy based on the front-to-rear acceleration Gx and the lateral acceleration Gy, and the larger the total acceleration Gxy is, the larger the value derived as the speed reduction indication value dBP.

[0123] Furthermore, the control unit 41 can derive the total acceleration Gxy using the following relationship (Equation 1).

[0124] [Formula 1]

[0125]

[0126] If the deceleration indication value dBP is derived, the control unit 41 performs operation processing in step S23. Then, if the braking force BPTr is indicated to be below the release determination value BPth in step S27 (yes), the control unit 41 ends the restriction processing.

[0127] Here, the steering control determination unit 43 determines whether the driver has started steering control based on the change in the steering control angle STR. For example, the steering control determination unit 43 derives the absolute value of the time derivative of the steering control angle STR as the steering control speed dSTR. Furthermore, the steering control determination unit 43 determines that steering control has started if the steering control speed dSTR is higher than or equal to the determined steering control speed dSTRth. On the other hand, the steering control determination unit 43 does not determine that steering control has started if the steering control speed dSTR is lower than the determined steering control speed dSTRth.

[0128] <Function and Effects of This Embodiment>

[0129] exist Figure 9The diagram shows the changes in the driver's operating amount X, steering angle STR, total acceleration Gxy, and front-to-back acceleration Gx when the driver releases the brake operating component 15.

[0130] like Figure 9 As shown in (a), (b), (c), and (d), if the driver applies braking force to the vehicle 10 by operating the braking operation component 15, the vehicle 10 decelerates.

[0131] exist Figure 10 schematically shown Figure 9 The positional relationship between the passenger's head 81 and the headrest 82 at time t51. At time t51, the vehicle 10 decelerates. Therefore, due to the inertial force caused by deceleration, the passenger's head 81 separates from the headrest 82 forward Df.

[0132] exist Figure 9 In the example shown, the operating amount X of the braking operation component 15 decreases starting from time t51. Furthermore, if the rate of decrease of the operating amount ΔX at time t52 is greater than or equal to the second determination rate of decrease ΔXth2, then a restriction process begins. Figure 9 In (d), the shift of acceleration Gx before and after the action is shown by a dashed line. That is, when the action is applied, the rate of decrease of braking force BP is smaller compared to the case without the action.

[0133] exist Figure 11 The diagram schematically illustrates the positional relationship between the passenger's head 81 and the headrest 82 during the period from time t52 to time t53. Figure 11 In the diagram, the dashed line indicates the position of header 81 without restriction processing. The solid line indicates the position of header 81 with restriction processing. For example... Figure 10 as well as Figure 11 As shown, without the restriction process, the front-rear acceleration Gx suddenly increases, so the inertial force caused by the deceleration of vehicle 10 suddenly decreases. As a result, the head 81 displaces in the opposite direction to the forward direction Df, i.e., the rearward direction Dr. In contrast, if the restriction process is initiated, although the front-rear acceleration Gx increases, the rate of increase of the front-rear acceleration Gx is smaller than in the case without the restriction process. In this case, although the inertial force caused by the deceleration of vehicle 10 decreases, the rate of decrease of the inertial force is smaller. Therefore, compared with the case without the restriction process, the rearward movement of the head 81 towards Dr can be suppressed.

[0134] exist Figure 9In the example shown, vehicle 10 is moving at time t53. Furthermore, the driver begins steering control from time t53. That is, the steering angle STR gradually increases. Thus, at time t54, it is determined that steering control has begun. In this case, due to the change in the speed reduction indication value dBP, the rate of decrease in braking force BP is smaller compared to before time t54. For example, braking force BP is maintained from time t54.

[0135] In addition, Figure 9 In (d), the shift of the forward and backward acceleration Gx in this embodiment is shown in solid line. The shift of the forward and backward acceleration Gx is shown in double-dotted line when the speed indication value dBP is not reduced regardless of whether the steering operation is changed, even when the limiting process is performed.

[0136] exist Figure 9 (c) shows the change in the total acceleration Gxy. Figure 9 In (c), the change in total acceleration Gxy without the restriction process is shown by a dashed line. The change in total acceleration Gxy under the conditions of this embodiment is shown by a solid line. The shift in the absolute value of total acceleration Gxy without reducing the speed indication value dBP based on the presence or absence of steering control is shown by a double-dotted line.

[0137] Without imposing any limiting measures, the rate of decrease in abrupt acceleration Gx is relatively large. Therefore, the total acceleration Gxy decreases. If steering control is determined to have begun at time t54, the lateral acceleration Gy increases. On the other hand, the abrupt acceleration Gx decreases. Therefore, as time t54 passes, the total acceleration Gxy gradually increases. Even when the acceleration Gx becomes zero around time t55, the steering angle STR increases. Furthermore, the steering angle STR remains constant at time t56. Therefore, after time t56, the total acceleration Gxy remains constant.

[0138] In cases where the total acceleration Gxy changes as described above, if the lateral acceleration Gy increases due to the initiation of steering maneuvers, then... Figure 11 as well as Figure 12 As shown by the dashed line, the head of the passenger 81 displaces relatively large laterally to Ds. Furthermore, at time t56 while maintaining the steering angle STR, as... Figure 12 as well as Figure 13 As shown by the dashed line, head 81 shifts forward again by Df. If no restriction is applied, head 81 shifts backward significantly by Dr, and then shifts laterally by Ds significantly. Afterward, head 81 shifts forward significantly by Df.

[0139] In contrast, in this embodiment, a restriction process is performed. Furthermore, if steering maneuvering begins during the restriction process, a period for maintaining the braking force BP is set. This period ends when the operation of the braking operation component 15 is released. After this period, the rate of decrease of the braking force BP is increased compared to the period in which it occurred. More specifically, as the total acceleration Gxy decreases, the rate of decrease of the braking force BP increases.

[0140] Therefore, the total acceleration Gxy is as follows Figure 9 The shift is as shown by the solid line in (c). That is, compared to the case without the restriction treatment, the change in the total acceleration Gxy is smaller.

[0141] The result, such as Figure 11 as well as Figure 12 As shown, even when the head 81 displaces laterally to Ds due to the increase in lateral acceleration Gy, the amount of lateral displacement of the head 81 to Ds can be reduced. Furthermore, the movement of the head 81 backward to Dr is suppressed by the execution of the restriction process (see reference). Figure 11 Therefore, it is less likely to cause forward displacement of the head 81 by Df. That is, it can suppress the displacement of the passenger's head 81. As a result, it can suppress discomfort felt by the passenger.

[0142] (Example of Change)

[0143] The above embodiments can be modified as follows. The above embodiments and the following modifications can be combined with each other within the scope of technical inconsistency.

[0144] • In the fifth embodiment described above, the smaller the vehicle speed VS at the beginning, the smaller the value can be set as the speed reduction indication value dBP at the beginning of the restriction process.

[0145] • In the fifth embodiment described above, the speed reduction indicator value dBP can also be reduced as the forward and backward acceleration Gx increases before making a determination that steering has begun.

[0146] In the fifth embodiment described above, if it is determined during the execution of the restriction process that steering has begun, the rate of reduction of the braking force BP is reduced compared to before the determination. However, this is not a limitation. The vehicle 10 is equipped with a monitoring system 50 and a navigation device that monitor the area surrounding the vehicle 10. Therefore, by analyzing the information obtained from the monitoring system 50 and the navigation device, it is possible to predict whether the driver has begun steering. For example, if the vehicle 10 is traveling close to a curve, it is possible to predict that the driver has begun steering. Furthermore, if the driver operates the direction indicator, it is possible to predict that the driver has begun steering if the vehicle 10 is permitted to move in the direction the driver wants to turn according to traffic lights or the like.

[0147] Therefore, during the execution of the restriction process, the steering control determination unit 43 determines whether it can be predicted that the driver will initiate steering control. Furthermore, if it is determined that steering control can be predicted, the rate of reduction of the braking force BP can be reduced from before the actual initiation of steering control compared to before the determination was made. In this case, the braking force BP can also be maintained. Afterwards, the operation of the brake operation component 15 is released, ending the period of decreasing the rate of reduction, and the rate of reduction of the braking force BP is gradually increased.

[0148] • In the fifth embodiment described above, during the execution of the restriction process, if it is determined that steering maneuvering has begun or that it can be predicted that steering maneuvering will begin, setting a period for maintaining the braking force BP is an example. For example, if a period is set in which the rate of decrease of the braking force BP is reduced compared to before the determination is made when it is determined that steering maneuvering has begun or that it can be predicted that steering maneuvering will begin, the braking force BP can also be reduced during this period.

[0149] Alternatively, the aforementioned period may end at a time different from the moment the driver releases control of the braking operation component 15. For example, the period may end when the total acceleration Gxy decreases from its peak value by a predetermined amount.

[0150] Alternatively, the aforementioned period can be set from the moment when the steering maneuver is determined to have begun until a predetermined time has elapsed.

[0151] The steering control determination unit 43 may also determine whether steering control has started without using the steering control speed dSTR. For example, the steering control determination unit 43 may determine that steering control has started if the change in steering control angle STR from the steering control angle STR at the time when steering control has never started is above a threshold.

[0152] The rollback process can be different from the one described in the fourth embodiment above, as long as it can increase the rate of decrease of the braking force BP compared to the execution of the limiting process. For example, the product of the rate of decrease indication value dBP during the execution of the limiting process and the correction gain for rollback can be used as the rate of decrease indication value dBP during the execution of the rollback process, and the braking force BP can be reduced based on the rate of decrease indication value dBP.

[0153] • In the fourth and third embodiments described above, the smaller the vehicle speed VS at the beginning, the smaller the value can be set as the speed reduction indication value dBP at the beginning of the restriction process.

[0154] • In the fourth embodiment described above, the speed reduction indicator value dBP may be reduced by limiting the operation of the brake release mechanism 15 before the operation is performed. This is done by increasing the forward and backward acceleration Gx.

[0155] In the third embodiment described above, the reduction velocity indication value dBP is made variable based on the change in the preceding and following acceleration Gx during the execution of the limiting process, but this is not a limitation. For example, the reduction velocity indication value dBP may also be maintained at a value corresponding to the preceding and following acceleration Gx at the start of the limiting process during the limiting process.

[0156] In the second embodiment described above, the speed reduction indicator value dBP can be varied depending on whether the vehicle 10 is in motion or stationary at the start of the restriction process. In this case, the speed reduction indicator value dBP when the vehicle 10 is in motion at the start of the restriction process is larger than the speed reduction indicator value dBP when the vehicle 10 is stationary at the start of the restriction process.

[0157] ·exist Figure 2 In the derivation process of step S21 shown, the product of the reduction rate of the required braking force BPr at that moment and the specified gain can also be derived as the reduction rate indication value dBP. In this case, a positive value less than 1 can be set as the specified gain.

[0158] The braking determination unit 42 may determine whether the reduction of the operation amount X has started without using the reduction rate ΔX of the operation amount X. For example, the braking determination unit 42 may determine that the reduction of the operation amount X has started if the reduction amount from the operation amount X before the reduction of the operation amount X starts is above a threshold.

[0159] In the above embodiments, the vehicle 10 may also be a vehicle capable of generating regenerative braking force in addition to the braking force generated by actuating the braking mechanism 12, i.e., friction braking force. In this case, the control unit 41 controls the sum of the friction braking force and the regenerative braking force.

[0160] The braking mechanism 12 may also be an electric brake that can control the force that presses the friction material 123 against the rotating body 122 without the use of brake fluid.

[0161] In the above embodiments, the braking control device 40 is not limited to a device that has a CPU and a memory for storing programs and performs software processing. That is, the braking control device 40 can be configured as any one of the following (a) to (c).

[0162] (a) The braking control device 40 includes one or more processors that perform various processes according to a computer program. The processor includes a CPU and memories such as RAM and ROM. The memories store program code or instructions configured to cause the CPU to perform processes. Memory, or computer-readable medium, includes all usable media that can be accessed by a general-purpose or special-purpose computer.

[0163] (b) The braking control device 40 has one or more dedicated hardware circuits for performing various processes. Examples of dedicated hardware circuits include application-specific integrated circuits (ASICs) or FPGAs. Furthermore, ASIC is short for "Application Specific Integrated Circuit," and FPGA is short for "Field Programmable Gate Array."

[0164] (c) The braking control device 40 has a processor that performs a portion of various processes according to a computer program, and dedicated hardware circuitry that performs the remaining processes in the various processes.

Claims

1. A vehicle braking control device, which controls the braking force of a vehicle by activating a braking device, comprising: The control unit controls the braking force of the vehicle based on the amount of operation of the braking operating components; and The braking determination unit determines whether a reduction in the amount of braking has begun when braking force is applied to the vehicle by operating the aforementioned braking operation components. If the control unit determines that the reduction rate of the aforementioned operation quantity has begun and the reduction rate is above the reduction rate determination value, the control unit begins to limit the reduction rate of the braking force of the vehicle.

2. The vehicle braking control device according to claim 1, wherein, In the above-mentioned restriction process, the lower the vehicle speed when the reduction of the above-mentioned operation amount is determined to have begun, the more the control unit reduces the rate of reduction of the vehicle's braking force.

3. The vehicle braking control device according to claim 1, wherein, In the above-mentioned limiting process, the greater the forward and backward acceleration of the vehicle, the more the control unit reduces the rate at which the braking force of the vehicle decreases.

4. The vehicle braking control device according to claim 2, wherein, In the above-mentioned limiting process, the greater the forward and backward acceleration of the vehicle, the more the control unit reduces the rate at which the braking force of the vehicle decreases.

5. The braking control device for a vehicle according to any one of claims 1 to 4, wherein, If the operation of the braking operation component is released during the execution of the above-mentioned restriction process, the control unit ends the above-mentioned restriction process and performs a reversal process that increases the reduction speed of the braking force of the vehicle compared with the execution of the restriction process.

6. The braking control device for a vehicle according to any one of claims 1 to 4, wherein, have: The steering control determination unit determines whether steering control has begun or whether it can predict that steering control will begin. If, during the aforementioned restriction process, it is determined that steering has begun or that steering can be predicted to begin, the control unit sets a period during which the rate of decrease in the vehicle's braking force is reduced compared to before the determination was made, and after the period has elapsed, the rate of decrease in the vehicle's braking force is increased compared to during the period.

7. The vehicle braking control device according to claim 5, wherein, have: The steering control determination unit determines whether steering control has begun or whether it can predict that steering control will begin. If, during the aforementioned restriction process, it is determined that steering has begun or that steering can be predicted to begin, the control unit sets a period during which the rate of decrease in the vehicle's braking force is reduced compared to before the determination was made, and after the period has elapsed, the rate of decrease in the vehicle's braking force is increased compared to during the period.

Images