JP2018103790A - Vehicle brake control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle brake control device which improves controllability of brake equipment.SOLUTION: Electric brake mechanisms 21L, 21R are provided on both of left and right wheels of a vehicle respectively. A control device 50 for controlling each electric brake mechanism 21L, 21R comprises a brake control part 51 which performs brake processing such that driving of an electric motor 40 of one electric brake mechanism is started in advance, and the electric motor 40 of the other electric brake mechanism is started after a standby time has lapsed from a start time of driving of said electric motor 40, whereby a brake force for each rear wheel RL, RR is increased. In brake processing, the brake control part 51 decides the electric motor 40, of which driving is started in advance, from respective electric motors 40 on the basis of drive times of the respective electric motors 40.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicle braking control device applied to a braking device in which an electric braking mechanism is provided for each of left and right wheels of a vehicle.

  Patent Document 1 describes an example of a braking device in which an electric braking mechanism is provided for each of the left and right wheels of a vehicle. Each electric braking mechanism is configured to apply a braking force to the wheel by pressing a friction material against a rotating body that rotates integrally with the wheel by driving the electric motor.

  In the device described in Patent Document 1, when applying braking force to each wheel, the operation of one of the electric braking mechanisms is started first, and the operation of the same electric braking mechanism is started. The operation of the other electric braking mechanism is started after the standby time has elapsed from the start time. In this way, by shifting the operation start timing of both electric braking mechanisms, the inrush current generation timing at the start of the electric motor of one electric braking mechanism and the inrush current at the start of the electric motor of the other electric braking mechanism The occurrence timing is not duplicated.

  And after the end of the generation of the inrush current under the situation where the electric braking mechanism is operating, if the current value flowing through the electric motor becomes equal to or greater than the stop determination current value, the braking force applied to the wheel has reached the specified braking force. Since the determination can be made, the drive of the electric motor is stopped. In addition, since the current value is equal to or greater than the stop determination current value from the time when the driving of the electric motor is started to apply braking force to the wheels by the operation of the electric braking mechanism in this way, the driving of the electric motor is stopped. The length of time until the point in time is called “driving time”.

JP, 2006-124408, A

  The drive time of the electric braking mechanism differs due to manufacturing errors and assembly errors of the components of the mechanism, the degree of wear of the friction material, and the like. That is, the driving time may be different for each electric braking mechanism.

  In the braking device described in Patent Document 1, the electric braking mechanism that starts the operation first is determined in advance. Therefore, if the drive time of the electric motor of the electric brake mechanism that starts operation later than each of the electric brake mechanisms is longer than the drive time of the electric motor of the electric brake mechanism that starts operation first, the operation of the brake device The time required from the start to the end of the operation of the device becomes long, and the controllability of the braking device may be reduced.

  In the vehicle braking control apparatus for solving the above-described problems, the electric braking mechanisms corresponding to the left and right wheels of the vehicle rotate integrally with the wheels by driving the electric motors provided in the electric braking mechanisms, respectively. It is an apparatus applied to a braking device for a vehicle that is configured to apply a braking force to the wheel by pressing a friction material against the rotating body. The vehicle braking control device starts driving one of the electric motors first, and after the standby time has elapsed from the start of driving the same electric motor, A braking control unit that performs a braking process for increasing the braking force on each wheel by starting driving is provided. In the vehicle braking control apparatus based on such a premise, the braking control unit performs the same operation based on the driving time that is the time from the start of driving of each electric motor to the stop of driving of each electric motor in the braking process. Of the electric motors, the electric motor to be driven first is determined.

  According to the above configuration, in the braking process, among the electric motors of each electric braking mechanism, the driving start of the electric motor of the other electric braking mechanism is delayed by the standby time from the driving start of the electric motor of one electric braking mechanism. ing. Therefore, it is possible to prevent the generation timing of the inrush current in the electric motor of one electric braking mechanism from overlapping with the generation timing of the inrush current in the electric motor of the other electric braking mechanism.

  The drive time of the electric braking mechanism varies due to manufacturing errors and assembly errors of the components of the mechanism, the degree of wear of the friction material, and the like. In other words, it is presumed that the driving time of the electric motor does not change much in a certain electric braking mechanism.

  Therefore, in the above configuration, when the electric motor of each electric braking mechanism is driven by the braking process, the electric motor to be operated first (that is, one electric motor described above) is determined based on the driving time of each electric motor. I am doing so. Therefore, in the braking process, the controllability of the braking device can be improved as compared with the case where the electric motor that starts driving first is determined in advance.

  The braking process may be performed when the vehicle is stopped or may be performed while the vehicle is running. The braking control unit can start driving the electric motor having the longer driving time among the electric motors in the braking process performed when the vehicle is stopped and the braking process performed while the vehicle is running. preferable. According to this configuration, the drive start of the electric motor with the longer drive time is not later than the drive start of the electric motor with the shorter drive time. Therefore, it can suppress that the implementation time of a braking process becomes long.

  By the way, when the friction material is pressed against the rotating body by driving the electric motor to apply a braking force to the wheel, the value of the current flowing through the electric motor increases as the force pressing the friction material against the rotating body increases. When the braking process is performed, the time from the start of driving the electric motor to the time when the current value flowing through the electric motor after the friction material comes into contact with the rotating body becomes equal to the specified current value is defined time. And In this case, the braking control unit sets the standby time so that the larger the difference between the specified time of the one electric motor and the specified time of the other electric motor is, the larger the value is in the braking process performed while the vehicle is running. Preferably, driving of one electric motor is started first, and driving of the other electric motor is started after a standby time has elapsed from the start of driving of the same electric motor.

  When the braking process is performed while the vehicle is running, if the difference between the start timing of applying the braking force to the right wheel and the start timing of applying the braking force to the left wheel is large, the yaw moment resulting from the difference is May occur temporarily and the stability of the vehicle behavior may be temporarily reduced. In this regard, in the above configuration, in the braking process performed while the vehicle is traveling, first, the standby time is set such that the larger the difference between the specified time of the one electric motor and the specified time of the other electric motor, the larger the standby time. Is set, and the drive of each electric motor is controlled individually. Therefore, the timing at which the current value flowing through one electric motor that starts driving first becomes equal to the specified current value, and the timing at which the current value flowing through the other electric motor that starts driving later becomes equal to the specified current value. It can suppress that deviation becomes large. That is, it is possible to suppress an increase in the difference between the timing at which braking force starts to be applied to the wheel corresponding to one electric braking mechanism and the timing at which braking force starts to be applied to the wheel corresponding to the other electric braking mechanism. Therefore, when the braking process is performed while the vehicle is running, it is possible to suppress the yaw moment that is caused by the deviation from being temporarily generated in the vehicle.

  The braking control device for a vehicle includes a slippage determination unit that determines whether or not the vehicle has slipped, and a rotation monitoring unit that monitors the rotation state of each wheel. When it is determined that the sliding has occurred, the braking control unit may perform the braking process. In this case, in the braking process performed when it is determined that the vehicle has slipped, the braking control unit detects that both of the wheels are rotating. Of the electric motors, it is preferable to start driving the electric motor having the shorter drive time first.

  According to the above configuration, when the vehicle slips down and the rotation of both wheels is detected, the driving of the electric motor with the shorter driving time out of the electric motors has the longer driving time. This is started before the electric motor is driven. Therefore, the braking force of the vehicle can be increased at an early stage by executing the braking process as compared with the case where the driving of the electric motor having the longer driving time is started first. That is, it is possible to stop the vehicle sliding down early.

  On the other hand, in the braking process performed when it is determined that the vehicle is slipping down, the braking control unit rotates one wheel among the wheels while the other wheel rotates. When it is detected by the rotation monitoring unit that the motor is not present, it is preferable to start driving the electric motor corresponding to one of the electric motors first.

  According to the above configuration, when the vehicle is slipping down, one of the wheels is rotating while the other wheel is not rotating. The braking force applied to the other wheel can be increased before the braking force applied to the other wheel. Therefore, the rotation of the rotating wheel can be stopped at an early stage, and as a result, the sliding down of the vehicle can be stopped at an early stage.

  The vehicle braking control device may include a time measuring unit that measures the time for which each electric motor is driven. In this case, the driving time is preferably a time determined based on the measurement result of the time measuring unit at the time of the previous braking process. As described above, by using the driving time based on the result of the time measurement at the time of the previous braking process, it is possible to accurately determine the electric motor having the longer driving time among the electric motors.

The schematic diagram which shows a parking braking device provided with the control apparatus which is one Embodiment of the braking control apparatus of a vehicle, and a regular braking device. The figure which shows the functional structure of the control apparatus, and the outline of the cross-sectional structure of the electric braking mechanism by which an action is controlled by the control apparatus. The timing chart which shows transition of the electric current value which flows into the electric motor of the electric braking mechanism. The flowchart which shows the process routine performed in order to perform a brake process at the time of a vehicle stop or during vehicle travel. The flowchart (first half part) which shows the process routine performed in order to perform a braking process triggered by having determined that the vehicle has fallen. The flowchart (second half part) which shows the process routine performed in order to perform a braking process triggered by having determined that the vehicle has fallen. The flowchart which shows the process routine performed in order to determine standby time. (A), (b) is a timing chart in the case of implementing a braking process when a vehicle stops. (A), (b) is a timing chart in the case of implementing a braking process during vehicle travel.

Hereinafter, an embodiment of a vehicle braking control device will be described with reference to FIGS.
FIG. 1 illustrates a parking brake device 20 that is an example of a brake device including a control device 50 as a brake control device of the present embodiment, and a service brake device 10. As shown in FIG. 1, the parking brake device 20 is provided with electric braking mechanisms 21L and 21R for the left and right rear wheels RL and RR, respectively. Each electric brake mechanism 21L, 21R is provided with a wheel cylinder 28, respectively. Brake fluid is supplied into the wheel cylinders 28 by the service braking device 10. That is, the hydraulic pressure in the wheel cylinder 28 can be adjusted by the operation of the service brake device 10.

  The service braking device 10 includes a hydraulic pressure generating device 12 to which a brake pedal 11 is drivingly connected, and a braking actuator 13 disposed between the hydraulic pressure generating device 12 and each wheel cylinder 28. When the brake pedal 11 is operated by the driver of the vehicle, an amount of brake fluid corresponding to the amount of operation of the brake pedal 11 is supplied from the hydraulic pressure generator 12 into each wheel cylinder 28. The brake actuator 13 is operated so as to generate a differential pressure between the master chamber 121 provided in the hydraulic pressure generator 12 and the wheel cylinder 28.

Next, the electric braking mechanisms 21L and 21R will be described with reference to FIGS.
As shown in FIGS. 1 and 2, the electric braking mechanisms 21 </ b> L and 21 </ b> R are disposed on both sides of the brake disc 22, which is an example of a rotating body that rotates integrally with the rear wheels RL and RR, and the brake disc 22 in the vehicle width direction. And a pair of brake pads 23, 24. The brake pads 23 and 24 have a back plate 25 and a friction material 26 fixed to the back plate 25. When the brake pads 23, 24 approach the brake disk 22 and the friction material 26 is pressed against the brake disk 22, a braking force corresponding to a pressing force that is a force pressing the friction material 26 against the brake disk 22 is It is given to the rear wheels RL and RR. That is, the braking force applied to the rear wheels RL and RR can be increased by increasing the pressing force.

  As shown in FIG. 2, the electric brake mechanisms 21L and 21R are provided with calipers 27 that support the brake pads 23 and 24 in a state in which they can move relative to and away from the brake disk 22. . Among the brake pads 23, 24, the brake pad 23 is located on the inner side in the vehicle width direction than the brake disk 22, and a wheel cylinder 28 is provided on the caliper 27 on the inner side in the vehicle width direction than the brake pad 23. Yes. The wheel cylinder 28 is closed on the inner side in the vehicle width direction and opened on the outer side in the vehicle width direction. 30.

  The piston 30 has a substantially bottomed cylindrical shape whose outer side in the vehicle width direction is closed and whose inner side in the vehicle width direction is open, and the opening of the cylinder body 29 is closed by the piston 30. A cylinder chamber 31 is defined by the piston 30 and the cylinder body 29, and brake fluid is supplied to the cylinder chamber 31 from the service brake device 10. Therefore, when the hydraulic pressure in the cylinder chamber 31 increases and the piston 30 slides outward in the vehicle width direction on the left side in the drawing, the brake pads 23 and 24 approach the brake disc 22 by being pushed by the piston 30. On the other hand, when the hydraulic pressure in the cylinder chamber 31 decreases and the piston 30 slides inward in the vehicle width direction, which is the right side in the figure, the pressure on the brake pads 23 and 24 by the piston 30 is released, and both brake pads 23 and 24 Leaves the brake disc 22.

  The electric braking mechanisms 21L and 21R include an electric motor 40 that can rotate the output shaft 401 in both forward and reverse directions, a speed reduction mechanism 41 that decelerates and outputs the rotational speed of the output shaft 401 of the electric motor 40, and A nut 42 that is connected to the speed reduction mechanism 41 and moves forward and backward in the vehicle width direction is provided.

  The speed reduction mechanism 41 has a plurality of gears 411 arranged outside the cylinder body 29. When the electric motor 40 is driven, each gear 411 rotates in a direction according to the rotation direction of the output shaft 401. Further, a through hole 292 that penetrates in the vehicle width direction is formed in the center of the bottom wall 291 of the cylinder body 29, and the rod member 412 that is inserted into the through hole 292 of the bottom wall 291 is inserted into the speed reduction mechanism 41. Is provided. The rod member 412 is supported on the bottom wall 291 of the cylinder body 29 in a state where the rod member 412 can rotate according to the rotation of the gear 411. The peripheral surface of a portion of the rod member 412 located in the cylinder body 29 is subjected to male thread processing.

  The nut 42 is disposed in the cylinder chamber 31, more specifically, inside the piston 30. The inner peripheral surface of the nut 42 is internally threaded, and the nut 42 is screwed to the rod member 412. Therefore, when the rod member 412 rotates by driving the electric motor 40, the nut 42 moves to one side or the other side in the vehicle width direction. That is, the rotary motion of the electric motor 40 is converted into a linear motion by the rod member 412 and the nut 42 and transmitted to the piston 30. Then, by the operation of the electric braking mechanisms 21L and 21R resulting from the drive of the electric motor 40, a pressing force that is a force for pressing the friction material 26 against the brake disk 22, that is, a braking force is applied to the rear wheels RL and RR. it can.

Next, the control configuration of the parking brake device 20 will be described with reference to FIGS. 1 and 2.
As shown in FIGS. 1 and 2, the control device 50 of the parking brake device 20 includes a plurality (two in this embodiment) of wheel speed sensors 101 </ b> L and 101 </ b> R individually corresponding to the rear wheels RL and RR. It is connected to the. The wheel speed sensors 101L and 101R output signals corresponding to the wheel speed VW that is the rotational speed of the corresponding rear wheels RL and RR. The control device 50 is electrically connected to an operation unit 102 provided in the passenger compartment. The operation unit 102 is turned on when the braking force is applied to the rear wheels RL and RR by the operation of the parking brake device 20, while the braking force is applied to the rear wheels RL and RR by the operation of the parking brake device 20. It is turned off when canceling. The operation unit 102 outputs an on operation signal to the control device 50 when the on operation is performed, and outputs an off operation signal to the control device 50 when the off operation is performed.

  In addition, the control device 50 includes a braking control unit 51, a time measurement unit 52, a storage unit 53, a rotation monitoring unit 54, and a slippage determination unit 55 as functional units for operating the parking brake device 20.

  When an ON operation signal is input from the operation unit 102, the braking control unit 51 performs a braking process of operating the electric braking mechanisms 21L and 21R to apply a braking force to the rear wheels RL and RR. On the other hand, when an off operation signal is input from the operation unit 102, the brake control unit 51 releases the state in which the braking force is applied to the rear wheels RL and RR by operating the electric braking mechanisms 21L and 21R. A brake release process is performed.

  With reference to FIG. 3, the transition of the current value Imt flowing through the electric motor 40 when the electric braking mechanisms 21L and 21R are operated by the braking process will be described. FIG. 3 illustrates a case where the electric motor 40 is driven from a state in which the friction material 26 is separated from the brake disk 22.

  As shown in FIG. 3, when the driving of the electric motor 40 is started at the first timing t11, the current value Imt flowing through the electric motor 40 rapidly increases. The large current value Imt that flows in the initial driving of the electric motor 40 is referred to as “rush current”, and the initial driving of the electric motor 40 in which the rush current is generated is referred to as “rush current generation period TRM1”. In the period from the second timing t12 to the third timing t13, which is the end timing of the inrush current generation period TRM1, the friction material 26 is not yet in contact with the brake disk 22, and the load applied to the electric motor 40 is increased. Since it is small, the current value Imt does not increase. At the third timing t13, the friction material 26 comes into contact with the brake disk 22, and the load applied to the electric motor 40 gradually increases. For this reason, the current value Imt increases from the third timing t13. Then, it can be determined that the braking force is applied to the rear wheels RL and RR at the fourth timing t14 when the current value Imt reaches the specified current value ImtTh2. Note that the length of time from the first timing t11 at which the driving of the electric motor 40 is started to the fourth timing t14 at which the current value Imt reaches the specified current value ImtTh2 is referred to as “specified time TM1”. The specified current value ImtTh2 is set to a value larger than the current value Imt when the friction material 26 is not in contact with the brake disk 22 and the load applied to the electric motor 40 is small.

  If the current value Imt increases after the fourth timing t14, the braking force for the rear wheels RL, RR also increases. When the current value Imt reaches the stop determination current value ImtTh1 larger than the specified current value ImtTh2 at the fifth timing t15, it can be determined that sufficient braking force is applied to the rear wheels RL and RR. The drive of the motor 40 is stopped. The length of time from the first timing t11 at which the driving of the electric motor 40 is started to the fifth timing t15 at which the current value Imt reaches the stop determination current value ImtTh1 is referred to as “driving time TM2”.

  As described above, an inrush current is generated when the electric motor 40 is started. Therefore, during the braking process and the braking release process, the braking control unit 51 starts the operation of one of the electric braking mechanisms 21L and 21R first, and starts the operation of one of the electric braking mechanisms. After the standby time TS has elapsed from the point in time, the operation of the other electric braking mechanism is started. For this reason, generation | occurrence | production timing of the rush current in the electric motor 40 of one electric braking mechanism and the generation | occurrence | production timing of the rush current in the electric motor 40 of the other electric braking mechanism can be prevented from overlapping.

  In addition, as a case where the operation part 102 is turned on by the driver, for example, when the vehicle stops and maintains the stop state, and even when the driver operates the brake pedal 11 when the vehicle travels, The case where it is not decelerated can be mentioned. That is, the braking process may be performed both when the vehicle is stopped and while the vehicle is traveling.

  In addition, the pressing force that presses the friction material 26 against the brake disc 22 may be reduced under a situation in which a braking force is applied to the rear wheels RL and RR by the braking process. At this time, when the vehicle is stopped on a slope, the vehicle may slide down when the pressing force is reduced. In the present embodiment, when such a vehicle slip occurs, the braking process may be performed again to increase the braking force on the rear wheels RL and RR and stop the slip.

  Returning to FIG. 2, the time measuring unit 52 measures the specified time TM1 and the driving time TM2 for each of the electric braking mechanisms 21L and 21R when the braking control unit 51 is performing the braking process. And the time measurement part 52 memorize | stores the regulation time TM1 and drive time TM2 of the electric motor 40 in each electric braking mechanism 21L and 21R which measured in the memory | storage part 53, when a braking process is complete | finished.

  The rotation monitoring unit 54 monitors the rotation state of the rear wheels RL and RR under a situation in which braking force is applied to the rear wheels RL and RR by performing the braking process by the braking control unit 51. For example, the rotation monitoring unit 54 individually monitors the rotation state of each rear wheel RL, RR (for example, the wheel speed VW of each rear wheel RL, RR) based on signals from the wheel speed sensors 101L, 101R. ing. Then, when the rotation monitoring unit 54 detects the rotation of at least one rear wheel among the rear wheels RL and RR, the rotation monitoring unit 54 outputs that fact to the sliding determination unit 55 and the braking control unit 51.

  The slippage determination unit 55 detects that the vehicle has slipped when movement of the vehicle is detected even in a situation where braking force is applied to the rear wheels RL and RR by the execution of the braking process by the brake control unit 51. Is determined to have occurred. That is, the slippage determination unit 55 determines that a slippage has occurred when the rotation monitoring unit 54 has input that the rotation of at least one of the rear wheels RL and RR has been detected. can do. Then, when it is determined that the slip has occurred, the slippage determination unit 55 outputs that fact to the braking control unit 51.

  Next, referring to FIG. 4, a processing routine executed by the braking control unit 51 when the braking process is performed in a situation where the braking force resulting from the driving of the electric motor 40 is not applied to each of the rear wheels RL and RR. explain. This processing routine applies a braking force to each of the rear wheels RL and RR when the vehicle is stopped and a braking process is performed to maintain the stopped state, and when the electric motor 40 is driven while the vehicle is traveling. If executed.

  As shown in FIG. 4, in the present processing routine, the braking control unit 51 performs a determination process for determining the standby time TS (step S11). This determination process will be described later with reference to FIG. Subsequently, the braking control unit 51 reads the driving times TDL and TDR of the electric braking mechanisms 21L and 21R at the time of the previous braking process from the storage unit 53, and the driving time TDR of the right electric braking mechanism 21R is on the left side. It is determined whether or not the driving time TDL of the electric braking mechanism 21L is longer (step S12). The driving time TDL of the left electric braking mechanism 21L is the driving time TM2 (see FIG. 3) of the electric motor 40 of the electric braking mechanism 21L during the previous braking process. Similarly, the driving time TDR of the right electric braking mechanism 21R is the driving time TM2 (see FIG. 3) of the electric motor 40 of the electric braking mechanism 21R during the previous braking process. When the driving time TDR in the previous braking process is longer than the driving time TDL, the driving time TDR of the right electric braking mechanism 21R is longer than the driving time TDL of the left electric braking mechanism 21L even in the current braking process. It is predicted. On the other hand, when the driving time TDL at the time of the previous braking process is longer than the driving time TDR, the driving time TDL of the left electric braking mechanism 21L is longer than the driving time TDR of the right electric braking mechanism 21R even in this braking process. Expected to be longer.

  Therefore, when the drive time TDR is less than the drive time TDL (step S12: NO), the brake control unit 51 starts the operation of the left electric brake mechanism 21L, that is, the drive of the electric motor 40 of the electric brake mechanism 21L ( Step S13). Subsequently, the braking control unit 51 determines whether or not the elapsed time from the start of the operation of the left electric braking mechanism 21L has reached the standby time TS determined in step S11 (step S14). When the elapsed time has not reached the standby time TS (step S14: NO), the braking control unit 51 repeats the determination process of step S14 until the elapsed time reaches the standby time TS. On the other hand, when the elapsed time reaches the waiting time TS (step S14: YES), the braking control unit 51 starts the operation of the right electric braking mechanism 21R, that is, the driving of the electric motor 40 of the electric braking mechanism 21R (step S14). Thereafter, the process proceeds to step S19, which will be described later.

  On the other hand, in step S12, when the driving time TDR of the right electric braking mechanism 21R is equal to or longer than the driving time TDL of the left electric braking mechanism 21L in the previous braking process (YES), the braking control unit 51 The operation of the right electric braking mechanism 21R, that is, the driving of the electric motor 40 of the electric braking mechanism 21R is started (step S16). Subsequently, the braking control unit 51 determines whether or not the elapsed time from the start of operation of the right electric braking mechanism 21R has reached the standby time TS determined in step S11 (step S17). When the elapsed time has not reached the standby time TS (step S17: NO), the braking control unit 51 repeats the determination process of step S17 until the elapsed time reaches the standby time TS. On the other hand, when the elapsed time reaches the standby time TS (step S17: YES), the braking control unit 51 starts the operation of the left electric braking mechanism 21L, that is, the driving of the electric motor 40 of the electric braking mechanism 21L (step S17). After that, the process proceeds to step S19 described later.

  In step S <b> 19, the braking control unit 51 determines whether or not the inrush current generation timing has elapsed in the electric motor 40 of the electric braking mechanism that has started operation later. When the generation timing of the inrush current has not yet elapsed (step S19: NO), the braking control unit 51 repeats the determination process of step S19 until the generation timing has elapsed. On the other hand, when the generation timing of the inrush current has elapsed (step S19: YES), the braking control unit 51 proceeds to the next step S20.

  In step S20, the braking control unit 51 determines whether or not the current value Imt flowing through the electric motor 40 of the right electric braking mechanism 21R is equal to or greater than the stop determination current value ImtTh1. When the current value Imt is equal to or greater than the stop determination current value ImtTh1 (step S20: YES), the braking control unit 51 stops the operation of the right electric braking mechanism 21R, that is, drives the electric motor 40 of the electric braking mechanism 21R. The process is stopped (step S21), and then the process proceeds to step S22 described later. On the other hand, when the current value Imt is less than the stop determination current value ImtTh1 (step S20: NO), the braking control unit 51 proceeds to the next step S22 without performing the process of step S21.

  In step S22, the braking control unit 51 determines whether or not the current value Imt flowing through the electric motor 40 of the left electric braking mechanism 21L is equal to or greater than the stop determination current value ImtTh1. When the current value Imt is equal to or greater than the stop determination current value ImtTh1 (step S22: YES), the braking control unit 51 stops the operation of the left electric braking mechanism 21L, that is, drives the electric motor 40 of the electric braking mechanism 21L. The process is stopped (step S23), and then the process proceeds to step S24 described later. On the other hand, when the current value Imt is less than the stop determination current value ImtTh1 (step S22: NO), the brake control unit 51 proceeds to the next step S24 without performing the process of step S23.

  In step S24, the braking control unit 51 determines whether or not the operation of both the electric braking mechanisms 21L and 21R is stopped. When at least one of the electric braking mechanisms 21L and 21R is still operating (step S24: NO), the braking control unit 51 proceeds to step S20 described above. On the other hand, when the operation of the both electric braking mechanisms 21L and 21R has already stopped (step S24: YES), the braking control unit 51 ends this processing routine and ends the execution of the braking processing.

Next, with reference to FIGS. 5 and 6, a processing routine executed by the braking control unit 51 because it is input to the braking control unit 51 that it has been determined that the vehicle has slipped.
As shown in FIG. 5, in the present processing routine, the braking control unit 51 performs a determination process for determining the standby time TS (step S31). This determination process will be described later with reference to FIG. Subsequently, the braking control unit 51 determines whether rotation of both the left and right rear wheels RL and RR is detected (step S32). When the rotation of one of the rear wheels RL and RR is detected but the rotation of the other rear wheel is not detected (step S32: NO), the braking control unit 51 performs the process. The process proceeds to step S40 described later (see FIG. 6). On the other hand, when rotation of both rear wheels RL and RR is detected (step S32: YES), the brake control unit 51 proceeds to the next step S33.

  In step S33, the braking control unit 51 reads the driving times TDL and TDR of the electric braking mechanisms 21L and 21R at the time of the previous braking process from the storage unit 53, and the driving time TDR of the right electric braking mechanism 21R is on the left side. It is determined whether or not the driving time TDL of the electric braking mechanism 21L is equal to or longer. When the drive time TDR is less than the drive time TDL (step S33: NO), the brake control unit 51 starts the operation of the right electric brake mechanism 21R, that is, the drive of the electric motor 40 of the electric brake mechanism 21R (step S34). ). Subsequently, the braking control unit 51 determines whether or not the elapsed time from the start of the operation of the right electric braking mechanism 21R has reached the standby time TS determined in step S31 (step S35). When the elapsed time has not reached the standby time TS (step S35: NO), the braking control unit 51 repeats the determination process of step S35 until the elapsed time reaches the standby time TS. On the other hand, when the elapsed time reaches the standby time TS (step S35: YES), the braking control unit 51 starts the operation of the left electric braking mechanism 21L, that is, the driving of the electric motor 40 of the electric braking mechanism 21L (step S35). Thereafter, the process proceeds to step S47, which will be described later.

  On the other hand, when the driving time TDR is equal to or longer than the driving time TDL in step S33 (YES), the braking control unit 51 operates the left electric braking mechanism 21L, that is, drives the electric motor 40 of the electric braking mechanism 21L. Start (step S37). Subsequently, the braking control unit 51 determines whether or not the elapsed time from the start of the operation of the left electric braking mechanism 21L has reached the standby time TS determined in step S31 (step S38). If the elapsed time has not reached the standby time TS (step S38: NO), the braking control unit 51 repeats the determination process of step S38 until the elapsed time reaches the standby time TS. On the other hand, when the elapsed time reaches the standby time TS (step S38: YES), the braking control unit 51 starts the operation of the right electric braking mechanism 21R, that is, the drive of the electric motor 40 of the electric braking mechanism 21R (step S38). Thereafter, the process proceeds to step S47, which will be described later.

  As shown in FIG. 6, in step S40, the braking control unit 51 determines whether or not the rotation of the left rear wheel RL is detected. When rotation of the left rear wheel RL is detected (step S40: YES), the braking control unit 51 starts the operation of the left electric braking mechanism 21L, that is, the driving of the electric motor 40 of the electric braking mechanism 21L (step S40). S41). Subsequently, the braking control unit 51 determines whether or not the elapsed time from the start of the operation of the left electric braking mechanism 21L has reached the standby time TS determined in step S31 (step S42). When the elapsed time has not reached the standby time TS (step S42: NO), the braking control unit 51 repeats the determination process of step S42 until the elapsed time reaches the standby time TS. On the other hand, when the elapsed time reaches the standby time TS (step S42: YES), the braking control unit 51 starts the operation of the right electric braking mechanism 21R, that is, the driving of the electric motor 40 of the electric braking mechanism 21R (step S42). Thereafter, the process proceeds to step S47, which will be described later.

  On the other hand, when the rotation of the left rear wheel RL is not detected (step S40: NO), since the rotation of the right rear wheel RR is detected, the braking control unit 51 operates the right electric braking mechanism 21R, that is, Driving of the electric motor 40 of the electric braking mechanism 21R is started (step S44). Subsequently, the braking control unit 51 determines whether or not the elapsed time from the start of the operation of the right electric braking mechanism 21R has reached the standby time TS determined in step S31 (step S45). When the elapsed time has not reached the standby time TS (step S45: NO), the brake control unit 51 repeats the determination process of step S45 until the elapsed time reaches the standby time TS. On the other hand, when the elapsed time reaches the standby time TS (step S45: YES), the brake control unit 51 starts the operation of the left-side electric braking mechanism 21L, that is, the driving of the electric motor 40 of the electric braking mechanism 21L (step). Thereafter, the processing shifts to step S47 described later.

  As shown in FIG. 5, in step S <b> 47, the braking control unit 51 determines whether or not the inrush current generation timing has elapsed in the electric motor 40 of the electric braking mechanism that has started operation later. If the inrush current generation timing has not yet elapsed (step S47: NO), the braking control unit 51 repeats the determination process of step S47 until the occurrence timing elapses. On the other hand, when the generation timing of the inrush current has elapsed (step S47: YES), the braking control unit 51 proceeds to the next step S48.

  In step S48, the braking control unit 51 determines whether or not the current value Imt flowing through the electric motor 40 of the right electric braking mechanism 21R is equal to or greater than the stop determination current value ImtTh1. When the current value Imt is equal to or greater than the stop determination current value ImtTh1 (step S48: YES), the braking control unit 51 stops the operation of the right electric braking mechanism 21R, that is, drives the electric motor 40 of the electric braking mechanism 21R. The process is stopped (step S49), and then the process proceeds to step S50 described later. On the other hand, when the current value Imt is less than the stop determination current value ImtTh1 (step S48: NO), the brake control unit 51 proceeds to the next step S50 without performing the process of step S49.

  In step S50, the braking control unit 51 determines whether or not the current value Imt flowing through the electric motor 40 of the left electric braking mechanism 21L is greater than or equal to the stop determination current value ImtTh1. When the current value Imt is equal to or greater than the stop determination current value ImtTh1 (step S50: YES), the braking control unit 51 stops the operation of the left electric braking mechanism 21L, that is, drives the electric motor 40 of the electric braking mechanism 21L. The process is stopped (step S51), and then the process proceeds to step S52 described later. On the other hand, when the current value Imt is less than the stop determination current value ImtTh1 (step S50: NO), the braking control unit 51 proceeds to the next step S52 without performing the process of step S51.

  In step S52, the braking control unit 51 determines whether or not the operation of both the electric braking mechanisms 21L and 21R is stopped. If at least one of the electric braking mechanisms 21L and 21R is still operating (step S52: NO), the braking control unit 51 proceeds to step S48 described above. On the other hand, when the operation of both the electric braking mechanisms 21L and 21R has already stopped (step S52: YES), the braking control unit 51 ends this processing routine and ends the execution of the braking processing.

Next, with reference to FIG. 7, the determination process (processing routine) of the standby time TS in steps S11 and S31 will be described.
As shown in FIG. 7, in the present processing routine, the braking control unit 51 determines whether or not the current braking process is performed while the vehicle is traveling (step S61). If the current braking process is not performed while the vehicle is running (step S61: NO), the braking control unit 51 makes the standby time TS equal to the reference standby time TSB (step S62), and ends this processing routine. . That is, in the present embodiment, the standby time TS is made equal to the reference standby time TSB in the braking process that is performed when the vehicle is stopped and the braking process that is performed when it is determined that the vehicle has slipped. . The reference standby time TSB is a timing for generating an inrush current in the electric motor 40 of the electric braking mechanism that starts operation first, and a timing for generating an inrush current in the electric motor 40 of the electric braking mechanism that starts operating later. Is set to a minimum value of the waiting time that can prevent the overlaps or a time slightly longer than the minimum value.

  On the other hand, when the current braking process is performed while the vehicle is traveling (step S61: YES), the braking control unit 51 reads from the storage unit 53 the electric braking mechanisms 21L and 21R at the time of the previous braking process. The specified times TDAL and TDAR are read (step S63). The specified time TDAL of the left electric braking mechanism 21L is the specified time TM1 (see FIG. 3) of the electric motor 40 of the electric braking mechanism 21L during the previous braking process. Similarly, the specified time TDAR of the electric braking mechanism 21R on the right side is the specified time TM1 (see FIG. 3) of the electric motor 40 of the electric braking mechanism 21R during the previous braking process. Then, the braking control unit 51 calculates a difference ΔTDA (= | TDAL−TDAR |) between the respective specified times TDAL and TDAR read from the storage unit 53 (step S64). Subsequently, the braking control unit 51 performs a calculation process of the standby time TS using the calculated difference ΔTDA (step S65). For example, the brake control unit 51 compares the difference ΔTDA with the reference standby time TSB in the calculation process, and makes the standby time TS equal to the reference standby time TSB when the difference ΔTDA is equal to or less than the reference standby time TSB. On the other hand, when the difference ΔTDA is larger than the reference standby time TSB, the braking control unit 51 makes the standby time TS equal to the difference ΔTDA. Thus, in the braking process performed while the vehicle is running, when the difference ΔTDA at the previous execution of the braking process is equal to or greater than the reference standby time TSB, the standby time TS is calculated so as to increase as the difference ΔTDA increases. The After calculating the standby time TS in this way, the braking control unit 51 ends this processing routine.

Next, with reference to FIG. 8, an operation when the operation unit 102 is turned on when the vehicle is stopped will be described together with effects.
As shown in FIGS. 8A and 8B, the operation unit 102 is turned on at the first timing t21 when the vehicle is stopped. In the example shown in FIG. 8, since the drive time TDR of the right electric brake mechanism 21R is longer than the drive time TDL of the left electric brake mechanism 21L at the time of the previous braking process, at the first timing t21, the right side The driving of the electric motor 40 of the electric braking mechanism 21R is started. Then, at the second timing t22 when the standby time TS (= reference standby time TSB) has elapsed from the first timing t21, the driving of the electric motor 40 of the left electric braking mechanism 21L is started.

  Thereafter, at a third timing t23, the current value Imt flowing through the electric motor 40 of the left-side electric braking mechanism 21L that has started to operate later among both the electric braking mechanisms 21L and 21R starts to increase. Therefore, after the third timing t23, the pressing force pressing the friction material 26 against the brake disc 22 by the left electric braking mechanism 21L gradually increases. Then, at the fifth timing t25 thereafter, the current value Imt flowing through the electric motor 40 of the left electric braking mechanism 21L becomes equal to or greater than the stop determination current value ImtTh1, so that the driving of the electric motor 40 is stopped. That is, the operation of the left electric braking mechanism 21L is stopped, and the braking force for the left rear wheel RL is maintained.

  On the other hand, in the electric braking mechanism 21R on the right side, at the fourth timing t24 after the third timing t23 and before the fifth timing t25, the electric braking mechanisms 21L and 21R first. The current value Imt flowing in the electric motor 40 of the right-side electric braking mechanism 21R that has started operation starts to increase. Then, at the sixth timing t26 after the fifth timing t25, the current value Imt flowing through the electric motor 40 of the right electric braking mechanism 21R becomes equal to or greater than the stop determination current value ImtTh1, so that the electric motor 40 is driven. Stopped. That is, the operation of the right electric braking mechanism 21R is stopped, and the braking force for the right rear wheel RR is maintained.

  The drive times TDL and TDR of the electric braking mechanisms 21L and 21R are values resulting from manufacturing errors and assembly errors of the components of the electric braking mechanisms 21L and 21R, the degree of wear of the friction material 26, and the like. In other words, in one electric braking mechanism, it is estimated that the driving time in the previous braking process and the driving time in the next braking process are substantially the same. Therefore, in the present embodiment, the electric braking mechanism that starts the operation first is determined based on the driving times TDL and TDR in the previous braking process. Specifically, in the braking process performed when the vehicle is stopped, the electric braking mechanism having the longer driving time TDL, TDR in the previous braking process (the electric braking mechanism 21R on the right side in the example shown in FIG. 8) is first. It is made to operate. Therefore, compared to the case where the electric braking mechanism with the shorter driving time TDL, TDR in the previous braking process (the left electric braking mechanism 21L in the example shown in FIG. 8) is operated first, the time for executing the braking process. Can be shortened.

Next, with reference to FIG. 9, an operation when the operation unit 102 is turned on while the vehicle is running will be described together with effects.
As shown in FIGS. 9A and 9B, the operation unit 102 is turned on at the first timing t31 when the vehicle is traveling. Also in the example shown in FIG. 9, since the drive time TDR of the right electric brake mechanism 21R is longer than the drive time TDL of the left electric brake mechanism 21L at the time of the previous braking process, at the first timing t31, the right side The driving of the electric motor 40 of the electric braking mechanism 21R is started. Then, at the second timing t32 when the standby time TS (> reference standby time TSB) has elapsed from the first timing t31, the driving of the electric motor 40 of the left electric braking mechanism 21L is started.

  When the braking process is performed while the vehicle is traveling in this way, the standby time TS is determined based on the difference ΔTDA when the previous braking process is performed. Therefore, the timing at which the current value Imt flowing in the electric motor 40 of the left electric braking mechanism 21L that has started operation reaches the specified current value ImtTh2 is set to the electric motor 40 of the right electric braking mechanism 21R that has started operation later. It is possible to approach the timing at which the flowing current value Imt reaches the specified current value ImtTh2. In the example shown in FIG. 9, the standby time TS is equal to the difference ΔTDA at the time of the previous braking process, and the current value Imt flowing through the electric motor 40 of the left-side electric braking mechanism 21L that has started the operation first is At the third timing t33 at which the specified current value ImtTh2 is reached, the current value Imt flowing through the electric motor 40 of the right-side electric braking mechanism 21R that has started operation reaches the specified current value ImtTh2.

  That is, in the present embodiment, the timing at which the braking force starts to be applied to the left rear wheel RL by the operation of the left electric braking mechanism 21L that has started the operation first, and the operation of the right electric braking mechanism 21R that has started the operation later. Therefore, it is possible to suppress an increase in deviation from the timing at which the braking force starts to be applied to the right rear wheel RR. Therefore, when the braking process is performed while the vehicle is running, it is possible to suppress the yaw moment that is caused by the deviation from being temporarily generated in the vehicle.

  Next, an effect and an effect when it is determined that the vehicle has slipped under the condition that the braking process is performed and the braking force is applied to the rear wheels RL and RR will be described together with the effects. As a premise, it is assumed that the drive time TDR of the right electric brake mechanism 21R is longer than the drive time TDL of the left electric brake mechanism 21L when the previous braking process is performed.

  When the vehicle is stopped on a slope, the braking force applied to the rear wheels RL and RR may be reduced although the braking release process is not performed, and the vehicle may fall down. When it is determined that the vehicle has slipped in this manner, the braking process is performed again to increase the braking force on each of the rear wheels RL and RR and stop the slipping.

  At this time, when it is detected that both the rear wheels RL and RR are rotating, the electric braking mechanism (in this case, the electric motor on the left side) of the electric braking mechanisms 21L and 21R whose driving time is less likely to be long. The operation of the braking mechanism 21L) is started first. Then, when the elapsed time from the start of the operation of the left electric braking mechanism 21L reaches the standby time TS (= reference standby time TSB), the electric braking mechanism (in this case, the right electric braking mechanism whose driving time tends to be longer). The operation of the braking mechanism 21R) is started. Therefore, the braking force of the vehicle can be increased earlier than in the case where the operation of the right electric braking mechanism 21R, which is the electric braking mechanism having the longer driving time, is started first. That is, it is possible to stop the vehicle sliding down early.

  On the other hand, the rotation of one rear wheel (for example, the right rear wheel RR) is detected among the rear wheels RL and RR, but the rotation of the other rear wheel (for example, the left rear wheel RL) is detected. If not, the operation of the electric braking mechanism corresponding to one of the rear wheels (in this case, the right electric braking mechanism 21R) is started first. When the elapsed time from the start of operation of the electric braking mechanism corresponding to one rear wheel reaches the standby time TS (= reference standby time TSB), the electric braking mechanism corresponding to the other rear wheel (in this case, The operation of the left electric braking mechanism 21L) is started. In other words, the braking force on one rear wheel whose rotation is detected can be increased early, so that the rotation of one rear wheel can be stopped early, and the vehicle slippage can be stopped early. Can be made.

The above embodiment may be changed to another embodiment as described below.
When the braking process is performed while the vehicle is traveling, the standby time TS may be determined using a parameter other than the difference ΔTDA when the previous braking process is performed. For example, during the execution of the braking process, the predetermined current value ImtF, which is the current value Imt when a predetermined time has elapsed from the start of driving of the electric motor 40, is acquired. The predetermined time is set in advance such that the friction material 26 is reliably pressed against the brake disk 22. In this case, the predetermined current value ImtF tends to increase as the time from the start of driving of the electric motor 40 to the time when the braking force on the wheel reaches the predetermined braking force is shorter.

  Therefore, when the next braking process is performed while the vehicle is running, the predetermined current value ImtF of the right electric braking mechanism 21R and the predetermined current value ImtF of the left electric braking mechanism 21L at the time of the previous braking process are performed. The waiting time TS may be calculated based on the difference between the two. Even in such a control configuration, the braking force is started to be applied to the rear wheel by the operation of the electric braking mechanism that has started the operation first, and the rear wheel is controlled by the operation of the electric braking mechanism that has started the operation later. It is possible to suppress an increase in deviation from the timing at which power is applied.

  A technique using an electric braking mechanism as a service brake is also known. In this case, when the brake pedal 11 is operated by the driver, the braking force is applied to the rear wheels RL and RR by the operation of each electric braking mechanism. Even in this case, if the difference between the start timing of applying the braking force to the left rear wheel RL and the start timing of applying the braking force to the right rear wheel RR is large, the stability of the vehicle behavior temporarily decreases due to vehicle braking. There is a fear. Therefore, even in this case, when each braking mechanism is applied to the rear wheels RL and RR while the vehicle is running, the difference ΔTDA at the previous activation of each braking mechanism is used. The standby time TS may be calculated.

  In the above embodiment, the standby time TS is calculated based on the difference ΔTDA between the specified times TDAL and TDAR of the respective electric braking mechanisms 21L and 21R acquired during the previous braking process. The specified times TDAL and TDAR used for the calculation of the standby time TS may not be the specified times acquired during the previous braking process. For example, when the specified times TDAL and TDAR of the respective electric braking mechanisms 21L and 21R are acquired in advance by experiments and the braking process is performed, the standby time TS is set based on the difference ΔTDA between the specified times TDAL and TDAR. You may make it calculate. Further, the specified times TDAL and TDAR may be values acquired during the last braking process. Furthermore, each prescribed time TDAL, TDAR may be an average value of each prescribed time acquired during each braking process performed before the execution of the current braking process.

-Even when the braking process is performed while the vehicle is running, the standby time TS may be fixed at a predetermined value (for example, the reference standby time TSB).
-When braking is performed because the vehicle has slipped, when one of the rear wheels RL and RR is rotating, the other rear wheel is not rotating. Even if it exists, you may make it start the action | operation of the electric braking mechanism with the shorter drive time at the time of implementation of the last braking process first.

  In the braking process when it is determined that the vehicle has slipped and one of the rear wheels RL, RR is rotating, but the other rear wheel is not rotating If the braking force for one rear wheel is increased by operating the electric braking mechanism corresponding to one rear wheel, the electric braking mechanism corresponding to the other rear wheel may not be operated.

  In the above embodiment, based on the drive times TDL and TDR of each electric motor 40 acquired at the time of the previous braking process, the electric motor to be driven first is determined from among the electric motors 40. However, the driving time for determining the electric motor to start driving first may not be the driving time acquired during the previous braking process. For example, the driving times TDL and TDR of the respective electric motors 40 are acquired in advance by experiments or the like, and in the braking process, the electric motor that starts driving first is determined based on the driving times TDL and TDR. Good. Further, in the braking process, the electric motor to be driven first may be determined based on the driving times TDL and TDR of each electric motor 40 acquired during the last braking process. Further, in the braking process, the electric motor to be driven first may be determined based on the average value of the driving times of the electric motors 40 acquired at the time of each braking process performed previously.

  As long as the control device 50 can acquire the wheel speed VW of the rear wheels RL and RR, the wheel speed sensors 101L and 101R may not be electrically connected to the control device 50. For example, the wheel speed VW of the rear wheels RL and RR may be input to the control device 50 via another control device 50. In addition, when a vehicle is provided with a communication bus for performing data communication between a plurality of in-vehicle control devices (including the control device 50), the control device 50 can connect the rear wheels RL and RR via the communication bus. The wheel speed VW may be acquired.

  The electric braking mechanism may have a configuration other than the mechanism described in the above embodiment as long as the braking force can be applied to the wheel by driving the electric motor included in the electric braking mechanism. For example, an electric braking mechanism has a brake drum as a rotating body that rotates integrally with a wheel, and can apply a braking force to the wheel by pressing a friction material against the brake drum by driving an electric motor. An electric braking mechanism may be used.

DESCRIPTION OF SYMBOLS 20 ... Parking brake device, 21L, 21R ... Electric brake mechanism, 22 ... Brake disk which is an example of a rotary body, 26 ... Friction material, 40 ... Electric motor, 50 ... Control device as a brake control device, 51 ... Brake control part , 52 ... Time measuring part, 54 ... Rotation monitoring part, 55 ... Slip-down determination part, RL, RR ... Rear wheel.

Claims (6)

An electric braking mechanism corresponding to each of the left and right wheels of the vehicle controls the wheel by pressing a friction material against a rotating body that rotates integrally with the wheel by driving an electric motor provided in each of the electric braking mechanisms. Applied to vehicle braking devices each configured to provide power,
Of the electric motors, driving one of the electric motors is started first, and after the standby time has elapsed from the start of driving the same electric motor, driving of the other electric motor is started. In the braking control device for a vehicle, including a braking control unit that performs a braking process for increasing the braking force on each wheel.
The braking control unit is driven first among the electric motors based on a driving time which is a time from the start of driving of the electric motors to the stop of driving of the electric motors in the braking process. The vehicle braking control apparatus characterized by determining the electric motor for starting the vehicle. In the braking process that is performed when the vehicle is stopped and the braking process that is performed while the vehicle is running, the braking control unit first drives the electric motor having the longer driving time among the electric motors. The vehicle braking control device according to claim 1, wherein the vehicle braking control device is started. When the friction material is pressed against the rotating body by driving the electric motor to apply a braking force to the wheel, the current value flowing through the electric motor increases as the force pressing the friction material against the rotating body increases. And
The time from the start of driving of the electric motor to the time when the current value flowing through the electric motor when the friction material comes into contact with the rotating body becomes equal to the specified current value when the braking process is performed. If it is a specified time,
The braking control unit
In the braking process performed while the vehicle is running,
The standby time is set to be a larger value as the difference between the specified time of the one electric motor and the specified time of the other electric motor is larger,
The vehicle according to claim 2, wherein the driving of the one electric motor is started first, and the driving of the other electric motor is started after the waiting time has elapsed from the starting time of driving of the same electric motor. Braking control device. A slippage determination unit that determines whether or not a vehicle slippage has occurred;
A rotation monitoring unit that monitors the rotation state of each wheel, and
The braking control unit is configured to carry out the braking process when it is determined by the sliding determination unit that the vehicle is falling.
In the braking process performed when it is determined that the vehicle is slipping down, the braking control unit detects when both of the wheels are rotating by the rotation monitoring unit. The braking control device for a vehicle according to any one of claims 1 to 3, wherein driving of the electric motor having the shorter driving time among the electric motors is started first. A slippage determination unit that determines whether or not a vehicle slippage has occurred;
A rotation monitoring unit that monitors the rotation state of each wheel, and
The braking control unit is configured to perform the braking process when it is determined by the sliding determination unit that the vehicle is falling.
In the braking process performed when it is determined that the vehicle is slipping down, the braking control unit rotates one wheel of the wheels while the other wheel rotates. When it is detected by the rotation monitoring unit that the motor is not in operation, driving of the electric motor corresponding to the one wheel among the electric motors is started first. The vehicle brake control device according to the item. A time measuring unit for measuring the time for which each electric motor is driven;
The vehicle driving control device according to any one of claims 1 to 5, wherein the driving time is determined based on a measurement result of the time measuring unit at the time of the previous execution of the braking process.

Images