JP2015105075A - Vehicular braking control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular braking control system capable of suppressing a variation in a vehicle deceleration or a variation in a depression force in the case where a brake pedal is further depressed.SOLUTION: A regenerative collaboration controller includes a regenerative braking torque limit value designation unit (unit that performs processing described in the flowchart of Fig. 3) that designates a regenerative braking torque limit value according to a braking maneuver. Under regenerative collaboration control, a vehicular braking control system restricts a regenerative braking torque according to the regenerative braking torque limit value. When the regenerative braking torque limit value is modified along with a change in a brake pedal maneuver quantity, the regenerative braking torque limit value designation unit determines whether a change quantity in a depression force and a change quantity in a vehicle deceleration, which are attained after the regenerative braking torque limit value are modified, fall within permissible ranges (S7 and S13). If the change quantities exceed the permissible ranges, the regenerative braking torque limit value designation unit calculates as the regenerative braking torque limit value a regenerative torque limit value (after the variation in a depression force is corrected) (S8), and calculates a regenerative braking torque limit value (after a G variation is corrected) (S14).

Description

  The present invention relates to vehicle braking that performs regenerative cooperative control in which a hydraulic braking device that generates a master cylinder pressure by a driver's braking operation and a regenerative braking device that generates regenerative braking torque by rotation of a drive wheel are cooperatively operated. The present invention relates to a control device.

2. Description of the Related Art Conventionally, a vehicular brake control device that generates a driver's required deceleration by cooperatively operating a regenerative braking device and a friction (hydraulic pressure) braking device is known (see, for example, Patent Document 1).
In this prior art, the degree of change in the pedaling force that represents the magnitude of the fluctuation amount of the brake pedal reaction force is calculated, and as the degree of change in the pedaling force increases, the vehicle speed at which switching from regenerative braking torque to friction braking torque is started in the low vehicle speed range. It has been changed to the high vehicle speed side.

JP 2010-179742 A

However, in the above prior art, when the driver performs a step-up operation that increases the amount of depression of the brake pedal at the time of switching between the regenerative braking torque and the friction braking torque in the low vehicle speed range, the vehicle deceleration fluctuation and the pedaling force are reduced. There was a risk of fluctuation.
In other words, when the brake pedal is further depressed, the vehicle speed at which switching is started is changed to a higher vehicle speed than before the pedal depression operation, and the regenerative braking torque is suddenly reduced by this change, and the friction braking torque is increased. Is soared. At this time, since the responsiveness of the regenerative braking torque is higher than the responsiveness of the friction braking torque, the vehicle deceleration variation due to the coordination shift occurs, and the pedal depression force variation occurs due to the master cylinder pressure increase due to the sudden increase of the friction braking torque. .

  The present invention has been made paying attention to the above problem, and an object of the present invention is to provide a vehicle brake control device that can suppress vehicle deceleration fluctuations or pedaling force fluctuations when the brake pedal is further depressed.

In order to achieve the above object, a vehicle brake control device of the present invention includes:
The regenerative cooperative controller that executes regenerative cooperative control that controls the friction braking torque and the regenerative braking torque so that the total braking torque including the friction braking torque and the regenerative braking torque becomes the driver's required braking torque, A regenerative braking torque limit value setting unit for setting the regenerative braking torque limit value, and during the regenerative cooperative control, the regenerative braking torque limit value is limited by the regenerative braking torque limit value,
The regenerative braking torque limit value setting unit, when changing the regenerative braking torque limit value in accordance with a change in brake pedal operation amount, includes at least a pedaling force change amount and a vehicle deceleration change amount after the regenerative braking torque limit value change. It is determined whether one is within the allowable range, and when the allowable range is exceeded, the corrected regenerative braking torque limit value corrected so that the amount of change is within the allowable range is used as the regenerative braking torque limit value. The vehicle brake control device is characterized in that

In the vehicle brake control device of the present invention, when the driver increases the brake pedal depression, when the regenerative braking torque limit value is changed, the pedal force change amount and the vehicle deceleration change amount after the regenerative braking torque limit value change is changed. It is determined whether at least one of the values is within an allowable range. Then, if the allowable range is exceeded, the corrected regenerative braking torque limit value whose variation is within the allowable range is calculated as the regenerative braking torque limit value.
Therefore, the regenerative cooperative controller sets the regenerative braking torque during the switching control within the allowable range based on the corrected regenerative braking torque limit value at least one of the change amount of the pedal force and the vehicle deceleration change amount before and after the stepping operation. Can be suppressed.

1 is an overall system diagram showing a configuration of a hybrid vehicle to which a vehicle brake control device of Embodiment 1 is applied. 1 is an overall configuration diagram of a brake device used in a vehicle brake control device according to a first embodiment. 6 is a flowchart showing a flow of a process for setting a regenerative braking torque limit value in a regenerative braking torque limit value setting unit of the vehicle brake control device according to the first embodiment. FIG. 4 is a regenerative braking torque limit value map used in the process of step S <b> 2 of FIG. 3. FIG. 6 is a time chart illustrating an operation example of a comparative example with the vehicle brake control device of the first embodiment. 3 is a time chart illustrating an operation example of the vehicle brake control device according to the first embodiment. 6 is a map showing an example of a static characteristic of a pedal force target value with respect to an input rod stroke of the vehicle brake control device of the first embodiment. 3 is a map showing an example of a deceleration target value with respect to an input rod stroke of the vehicle brake control device of the first embodiment.

Hereinafter, the best mode for realizing the vehicle brake control device of the present invention will be described based on the first embodiment shown in the drawings.
First, the configuration of the vehicle brake control device of the first embodiment will be described.
The configuration of the hybrid vehicle including the vehicle brake control device according to the first embodiment will be described separately as “overall configuration”, “control system”, “configuration of brake device” [configuration and operation of brake booster].

[overall structure]
FIG. 1 is an overall system diagram showing the hybrid vehicle.
As shown in FIG. 1, the drive system of this hybrid vehicle includes an engine E, a first clutch CL1, a motor generator (regenerative braking device) MG, a second clutch CL2, an automatic transmission AT, and a propeller shaft PS. And a differential DF, a left drive shaft DSL, a right drive shaft DSR, a left rear wheel RL, and a right rear wheel RR. In addition, left driven wheels FL and right front wheels FR are provided as driven wheels.

  The engine E is, for example, a gasoline engine, and the valve opening degree of the throttle valve and the like are controlled based on a control command from an engine controller 101 described later. The engine output shaft is provided with a flywheel FW.

  The first clutch CL1 is a clutch interposed between the engine E and the motor generator MG. The first clutch CL1 is operated by a control hydraulic pressure generated by the first clutch hydraulic unit 106 based on a control command from a first clutch controller 105, which will be described later, and the engagement / disengagement including slip engagement is controlled. Specifically, the first clutch CL1 is a normally closed dry clutch that is fully engaged by the urging force of the leaf spring when not controlled. When a release command is output to the first clutch CL1, the hydraulic pressure corresponding to the transmission torque capacity command is supplied to the piston to make a stroke, and the transmission torque capacity corresponding to the stroke amount is set. When a stroke exceeding a predetermined value is performed, contact between the clutch plates is cut off and released. Further, in order to reduce friction loss when the clutch is released, the piston is further stroked by a predetermined amount by increasing the hydraulic pressure applied to the piston even after the clutch plate is disconnected.

  On the other hand, when the first clutch CL1 is engaged from the released state, the hydraulic pressure applied to the piston is gradually lowered. Then, the piston starts a stroke, and the clutch plate starts to come into contact when the piston strokes a predetermined amount (corresponding to backlash). Incidentally, whether or not the clutch plate is in contact can be determined by whether or not the engine speed Ne has started to increase. Thereafter, the lower the hydraulic pressure acting on the piston, the higher the transmission torque capacity.

Motor generator MG is a synchronous motor generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator. The motor generator MG is controlled by applying a three-phase alternating current formed by the inverter 103 based on a control command from a motor controller 102 described later.
In addition, motor generator MG can operate as an electric motor (regenerative braking device) that rotates by receiving power supplied from battery 104 (hereinafter, this state is referred to as “power running”). Furthermore, when the rotor is rotated by an external force, the motor generator MG can function as a generator that generates an electromotive force at both ends of the stator coil to charge the battery 104 (hereinafter, this operation state is referred to as “operating state”). Called "regeneration"). Note that the rotor of the motor generator MG is connected to the input shaft of the automatic transmission AT via a damper (not shown).

  The second clutch CL2 is a clutch interposed between the motor generator MG and the left and right rear wheels RL and RR. The second clutch CL2 is controlled to be engaged and disengaged including slip engagement by the control hydraulic pressure generated by the second clutch hydraulic unit 108 based on a control command from the AT controller 107 described later.

  The automatic transmission AT is a transmission that automatically switches stepped gear ratios such as forward five speeds and reverse first speeds according to the vehicle speed Vw, the accelerator opening APO, and the like. In the first embodiment, the second clutch CL2 is not newly added as a dedicated clutch, and some of the frictional engagement elements among a plurality of frictional engagement elements that are engaged at each gear stage of the automatic transmission AT are included. The element is diverted. Further, the second clutch CL2 may be provided independently between the motor generator MG and the automatic transmission AT.

  The output shaft of the automatic transmission AT is connected to the left and right rear wheels RL and RR via a propeller shaft PS, a differential DF, a left drive shaft DSL, and a right drive shaft DSR as vehicle drive shafts. The first clutch CL1 and the second clutch CL2 are, for example, wet multi-plate clutches that can continuously control the oil flow rate and hydraulic pressure with a proportional solenoid.

The drive system of this hybrid vehicle has three travel modes according to the engaged / released state of the first clutch CL1.
The first travel mode is abbreviated as an “electric vehicle travel mode” (hereinafter referred to as “EV travel mode”) as a motor use travel mode in which the first clutch CL1 is disengaged and travels using only the power of the motor generator MG as a power source. ).
The second travel mode is an engine use travel mode (hereinafter abbreviated as “HEV travel mode”) in which the first clutch CL1 is engaged and the engine E is included in the power source.

  The third travel mode is an engine use slip travel mode (hereinafter referred to as “WSC travel mode”) in which the second clutch CL2 is slip-controlled while the first clutch CL1 is engaged, and the engine E is included in the power source. Abbreviated). This WSC mode is a mode in which creep running can be achieved particularly when the battery SOC is low or the engine water temperature is low. When transitioning from the EV travel mode to the HEV travel mode, the first clutch CL1 is engaged and the engine is started using the torque of the motor generator MG.

Further, in the “HEV travel mode”, three travel modes of “engine travel mode”, “motor assist travel mode”, and “travel power generation mode” are set.
In the “engine running mode”, the left and right rear wheels RL and RR as drive wheels are moved using only the engine E as a power source. In the “motor-assisted travel mode”, the left and right rear wheels RL and RR as drive wheels are moved using the engine E and the motor generator MG as power sources. In the “running power generation mode”, the engine generator MG is caused to function as a power generator while the left and right rear wheels RL and RR as drive wheels are moved using the engine E as a power source.

During constant speed operation or acceleration operation, motor generator MG is operated as a generator using the power of engine E. Further, during deceleration operation, braking energy is regenerated and electric power is generated by the motor generator MG, which is used for charging the battery 104.
Further, as a further mode, there is a power generation mode in which the motor generator MG is operated as a generator using the power of the engine E when the vehicle is stopped.

[Control system]
Next, the control system of the hybrid vehicle will be described.
As shown in FIG. 1, the hybrid vehicle control system includes an engine controller 101, a motor controller 102, an inverter 103, a battery 104, a first clutch controller 105, a first clutch hydraulic unit 106, and an AT controller 107. And the second clutch hydraulic unit 108, the brake device 1, and an integrated controller (regenerative coordination controller) 110. The engine controller 101, the motor controller 102, the first clutch controller 105, the AT controller 107, the brake device 1, and the integrated controller 110 are connected via a CAN communication line 111 that can exchange information with each other. Has been.

  The engine controller 101 inputs engine speed information from the engine speed sensor 112 and controls an engine operating point (Ne: engine speed, Te: engine torque) in accordance with a target engine torque command or the like from the integrated controller 110. Command to output. This command output is output, for example, to a throttle valve actuator (not shown). Information such as the engine speed Ne is supplied to the integrated controller 110 via the CAN communication line 111.

  The motor controller 102 inputs information from the resolver 113 that detects the rotor rotational position of the motor generator MG. Then, a command for controlling the motor operating point (Nm: motor generator rotational speed, Tm: motor generator torque) of motor generator MG is output to inverter 103 in accordance with a target motor generator torque command or the like from integrated controller 110. The motor controller 102 monitors the battery SOC indicating the state of charge of the battery 104. The battery SOC information is used as control information for the motor generator MG and supplied to the integrated controller 110 via the CAN communication line 111. Is done.

  The first clutch controller 105 inputs sensor information from the first clutch oil pressure sensor 114 and the first clutch stroke sensor 115. Then, in response to the first clutch control command from the integrated controller 110, a command for controlling the engagement / release of the first clutch CL1 is output to the first clutch hydraulic unit 106. Information on the first clutch stroke C1S is supplied to the integrated controller 110 via the CAN communication line 111.

  The AT controller 107 inputs sensor information from an accelerator opening sensor 116, a vehicle speed sensor 117, a second clutch hydraulic pressure sensor 118, and an inhibitor switch that outputs a signal corresponding to the position of the shift lever operated by the driver. In response to the second clutch control command from the integrated controller 110, a command for controlling the engagement / release of the second clutch CL2 is output to the second clutch hydraulic unit 108 in the AT hydraulic control valve. Information on the accelerator opening APO, the vehicle speed Vw, and the inhibitor switch is supplied to the integrated controller 110 via the CAN communication line 111.

  The brake device 1 applies a friction braking torque to each wheel according to a driver's braking operation. Further, the friction braking torque is adjusted based on the regenerative cooperative control command from the integrated controller 110. The regeneration cooperative control will be described later.

  The integrated controller 110 manages the energy consumption of the entire vehicle and has a function for running the vehicle with the highest efficiency. The integrated controller 110 detects the motor rotation speed Nm, and the second clutch output rotation speed N2out. A second clutch output speed sensor 122 for detecting the second clutch torque, a second clutch torque sensor 123 for detecting the second clutch transmission torque capacity TCL2 (second clutch torque), and a wheel speed sensor 124 for detecting the wheel speeds of the four wheels. Each sensor information from the G sensor 125 that detects longitudinal acceleration and information obtained through the CAN communication line 111 are input.

  The integrated controller 110 controls the operation of the engine E based on the control command to the engine controller 101, the operation control of the motor generator MG based on the control command to the motor controller 102, and the first clutch CL1 based on the control command to the first clutch controller 105. Engagement / release control, engagement / release control of the second clutch CL2 by a control command to the AT controller 107, and operation control of the brake device 1 by a control command to the brake controller 109.

  The integrated controller 110 calculates the target deceleration with respect to the brake pedal depression amount of the driver, and gives priority to the regenerative braking torque with respect to the calculated target deceleration. The energy is recovered by regenerative braking up to a lower vehicle speed.

  On the other hand, the regenerative braking torque has an upper limit depending on the number of revolutions determined by the vehicle speed. Therefore, if the deceleration by the regenerative braking torque is insufficient for the target deceleration, regenerative cooperative control will compensate for the shortage with the friction braking torque. The command is output to the brake device 1.

[Configuration of brake device]
FIG. 2 is an overall configuration diagram of the brake device 1 used in the vehicle brake control device of the first embodiment. The brake device 1 includes a master cylinder 2, a reservoir tank RES, wheel cylinders 4 a to 4 d provided on each wheel, a brake booster 5 provided in connection with the master cylinder 2, and an input rod (input member) 6. And a brake operation amount detection device 7 and a master cylinder pressure control device 8 for controlling the brake booster 5.

The input rod 6 makes a stroke (advance and retreat) together with the brake pedal BP, and increases or decreases the hydraulic pressure in the master cylinder 2 (hereinafter, master cylinder pressure Pmc). The brake booster 5 and the master cylinder pressure controller 8 stroke the primary piston (assist member) 2b of the master cylinder 2 to increase or decrease the master cylinder pressure Pmc.
Hereinafter, for the sake of explanation, the x axis is set in the axial direction of the master cylinder 2, the brake pedal BP side is set as the negative direction, and the stepping stroke direction is set as the positive direction.

  The master cylinder 2 is a so-called tandem type, and has a primary piston 2b and a secondary piston 2c in the cylinder 2a. A primary hydraulic chamber 2d as a first hydraulic chamber is formed between the inner peripheral surface of the cylinder 2a and the surface of the primary piston 2b on the x axis positive direction side and the surface of the secondary piston 2c on the x axis negative direction side. Has been. A secondary fluid chamber 2e as a second fluid pressure chamber is formed between the inner peripheral surface of the cylinder 2a and the surface of the secondary piston 2c on the x-axis positive direction side.

The primary hydraulic chamber 2 d is connected so as to be able to communicate with the primary circuit 10, and the secondary hydraulic chamber 2 e is connected so as to be able to communicate with the secondary circuit 20. The volume of the primary hydraulic chamber 2d changes as the primary piston 2b and the secondary piston 2c stroke in the cylinder 2a. In the primary hydraulic pressure chamber 2d, a return spring 2f that urges the primary piston 2b in the negative x-axis direction is installed. The volume of the secondary liquid chamber 2e changes as the secondary piston 2c strokes in the cylinder 2a. In the secondary liquid chamber 2e, a return spring 2g that urges the secondary piston 2c to the x-axis negative direction side is installed.
The primary circuit 10 and the secondary circuit 20 are provided with a fluid pressure control unit 100 including various valves, motor pumps, reservoirs, and the like that can independently control each wheel cylinder pressure in order to perform ABS control and the like. ing.

  The primary circuit 10 is provided with a primary hydraulic pressure sensor 13, and the secondary circuit 20 is provided with a secondary hydraulic pressure sensor 14. The primary hydraulic pressure sensor 13 detects the hydraulic pressure in the primary hydraulic pressure chamber 2d, the secondary hydraulic pressure sensor 14 detects the hydraulic pressure in the secondary hydraulic chamber 2e, and these hydraulic pressure information is sent to the master cylinder pressure control device 8. Sent.

  One end 6a on the x-axis positive direction side of the input rod 6 passes through the partition wall 2h of the primary piston 2b and is installed in the primary hydraulic chamber 2d. The gap between the one end 6a of the input rod 6 and the partition wall 2h of the primary piston 2b is sealed to ensure liquid tightness and the one end 6a is slidable in the x-axis direction with respect to the partition wall 2h. . On the other hand, the other end 6b of the input rod 6 on the x-axis negative direction side is connected to the brake pedal BP.

  Therefore, when the driver steps on the brake pedal BP, the input rod 6 moves to the x-axis positive direction side, and when the driver returns the brake pedal BP, the input rod 6 moves to the x-axis negative direction side.

  The input rod 6 is formed with a large-diameter portion 6f having a larger diameter than the inner periphery of the partition wall 2h of the primary piston 2b and a smaller diameter than the outer diameter of the flange portion 6c. A gap L1 is provided between the x-axis positive direction end face of the large diameter portion 6f and the x-axis negative direction end face of the partition wall 2h when the brake is not operated. When the regenerative cooperative control command is received from the integrated controller 110 by this gap L1, the frictional braking torque is increased by the regenerative braking torque by moving the primary piston 2b relative to the input rod 6 in the negative x-axis direction. It is possible to reduce. When the input rod 6 is displaced relative to the primary piston 2b by the gap L1 in the x-axis positive direction, the surface of the large-diameter portion 6f in the x-axis positive direction comes into contact with the partition wall 2h. The primary piston 2b can move integrally.

  When the input rod 6 or the primary piston 2b moves in the positive x-axis direction, the hydraulic fluid in the primary hydraulic chamber 2d is pressurized, and the pressurized hydraulic fluid is supplied to the primary circuit 10. Further, the secondary piston 2c is moved to the x-axis positive direction side by the pressure of the primary hydraulic chamber 2d by the pressurized hydraulic fluid. When the secondary piston 2c moves to the x axis positive direction side, the hydraulic fluid in the secondary fluid chamber 2e is pressurized, and the pressurized hydraulic fluid is supplied to the secondary circuit 20.

  As described above, the input rod 6 moves in conjunction with the brake pedal BP to pressurize the primary hydraulic chamber 2d. Thus, even if the drive motor (actuator) 50 of the brake booster 5 stops due to a failure, the master cylinder pressure Pmc can be increased by the driver's brake operation, and a predetermined braking torque can be secured. Further, since a force corresponding to the master cylinder pressure Pmc acts on the brake pedal BP via the input rod 6 and is transmitted to the driver as a brake pedal reaction force, the brake pedal reaction force required when the above configuration is not adopted. A device such as a spring for generating force is not required. Therefore, the brake booster can be reduced in size and weight, and the mounting property on the vehicle is improved.

  The brake operation amount detection device 7 is for detecting the driver's requested deceleration, and is provided on the other end 6 b side of the input rod 6. The brake operation amount detection device 7 is a stroke sensor that detects a displacement amount (stroke) of the input rod 6 in the x-axis direction, that is, a stroke sensor of the brake pedal BP.

  The reservoir tank RES has at least two liquid chambers (not shown) separated from each other by a partition wall (not shown). Each fluid chamber is connected to the primary fluid pressure chamber 2d and the secondary fluid chamber 2e of the master cylinder 2 via the brake circuits 11 and 12, respectively.

  The wheel cylinders (friction braking devices) 4a to 4d have cylinders, pistons, pads, and the like. The pistons are moved by the hydraulic fluid supplied by the cylinders 2a, and the pads connected to the pistons are connected to the disk rotors 40a to 40d. It presses to 40d. The disc rotors 40a to 40d rotate integrally with each wheel, and the brake torque that acts on the disc rotors 40a to 40d becomes a braking force that acts between each wheel and the road surface.

  The brake booster 5 controls the displacement of the primary piston 2b, that is, the master cylinder pressure Pmc in accordance with the control command of the master cylinder pressure controller 8, and includes a drive motor 50, a speed reducer 51, and rotation-translation conversion. And a device 55. The master cylinder pressure control device 8 is an arithmetic processing circuit, and controls the operation of the drive motor 50 based on sensor signals from the brake operation amount detection device 7 and the drive motor 50.

[Configuration and operation of brake booster]
Next, the configuration and operation of the brake booster 5 will be described.
The drive motor 50 is a three-phase DC brushless motor, and operates with electric power supplied based on a control command from the master cylinder pressure control device 8 to generate a desired rotational torque.

  The reduction gear 51 decelerates the output rotation of the drive motor 50 by a pulley deceleration method. The reduction gear 51 includes a small-diameter drive pulley 52 provided on the output shaft of the drive motor 50, a large-diameter driven pulley 53 provided on the ball screw nut 56 of the rotation-translation conversion device 55, the drive-side pulley 52, and the follower. And a belt 54 wound around the side pulley 53. The reduction gear 51 amplifies the rotational torque of the drive motor 50 by the reduction ratio (radius ratio of the driving pulley 52 and the driven pulley 53) and transmits the amplified torque to the rotation-translation converter 55.

  The rotation-translation converter 55 converts the rotational power of the drive motor 50 into translation power, and presses the primary piston 2b with this translation power. In the first embodiment, a ball screw system is adopted as the power conversion mechanism, and the rotation-translation conversion device 55 includes a ball screw nut 56, a ball screw shaft 57, a movable member 58, and a return spring 59. Yes.

  The first housing member HSG1 is connected to the x-axis negative direction side of the master cylinder 2, and the second housing member HSG2 is connected to the x-axis negative direction side of the first housing member HSG1. The ball screw nut 56 is installed on the inner periphery of the bearing BRG provided in the second housing member HSG2 so as to be rotatable. A driven pulley 53 is fitted to the outer periphery of the ball screw nut 56 on the x-axis negative direction side. A hollow ball screw shaft 57 is coupled to the inner periphery of the ball screw nut 56 by meshing the screws. A plurality of balls are rotatably installed in the gap between the ball screw nut 56 and the ball screw shaft 57.

  A movable member 58 is integrally provided at the end of the ball screw shaft 57 on the x-axis positive direction side, and the primary piston 2b is joined to the surface of the movable member 58 on the x-axis positive direction side. The primary piston 2b is housed in the first housing member HSG1, and the end of the primary piston 2b on the x-axis positive direction side protrudes from the first housing member HSG1 and is fitted to the inner periphery of the master cylinder 2.

  A return spring 59 is provided in the first housing member HSG1 and on the outer periphery of the primary piston 2b. The return spring 59 has an end on the x-axis positive direction side fixed to the surface A on the x-axis positive direction side inside the first housing member HSG1, while an end on the x-axis negative direction side is engaged with the movable member 58. Has been. The return spring 59 is installed to be compressed in the x-axis direction between the surface A and the movable member 58, and urges the movable member 58 and the ball screw shaft 57 to the x-axis negative direction side.

  When the driven pulley 53 rotates, the ball screw nut 56 rotates as a unit, and the ball screw shaft 57 translates in the x-axis direction by the rotational movement of the ball screw nut 56. The primary piston 2b is pressed to the x-axis positive direction side via the movable member 58 by the thrust of the translational motion of the ball screw shaft 57 to the x-axis positive direction side. FIG. 2 shows a state in which the ball screw shaft 57 is at the initial position where the ball screw shaft 57 is displaced to the maximum in the negative x-axis direction when the brake is not operated.

  On the other hand, the elastic force of the return spring 59 acts on the ball screw shaft 57 in the opposite direction (x-axis negative direction side) to the thrust in the x-axis positive direction side. Thus, during braking (in the state where the primary piston 2b is pressed in the positive direction of the x-axis and the master cylinder pressure Pmc is increased), the drive motor 50 stops due to a failure and the return control of the ball screw shaft 57 is impossible. Even in this case, the ball screw shaft 57 returns to the initial position by the reaction force of the return spring 59. As a result, the master cylinder pressure Pmc decreases to near zero, so that it is possible to prevent the occurrence of dragging of the braking force and to avoid the situation where the vehicle behavior becomes unstable due to the dragging.

  A pair of springs (biasing members) 6d and 6e are disposed in the annular space B defined between the input rod 6 and the primary piston 2b. One end of each of the pair of springs 6d and 6e is locked to a flange portion 6c provided on the input rod 6, the other end of the spring 6d is locked to a partition wall 2h of the primary piston 2b, and the other end of the spring 6e is movable. Locked to the member 58. The pair of springs 6d and 6e bias the input rod 6 toward the neutral position of the relative displacement of the primary piston 2b, and the neutral movement of the input rod 6 and the primary piston 2b when the brake is not operated. It has a function to hold in position. By the pair of springs 6d and 6e, when the input rod 6 and the primary piston 2b are relatively displaced in any direction from the neutral position, a biasing force that returns the input rod 6 to the neutral position acts on the primary piston 2b. .

  The drive motor 50 is provided with, for example, a rotation angle detection sensor 50a such as a resolver 113, and the position signal of the motor output shaft detected thereby is input to the master cylinder pressure control device 8. The master cylinder pressure control device 8 calculates the rotation angle of the drive motor 50 based on the input position signal, and based on this rotation angle, calculates the propulsion amount of the rotation-translation conversion device 55, that is, the displacement amount of the primary piston 2b in the x-axis direction. calculate.

  Next, the amplifying action of the thrust of the input rod 6 by the brake booster 5 and the master cylinder pressure controller 8 will be described. In the first embodiment, the master cylinder pressure control device 8 controls the displacement of the primary piston 2b according to the displacement of the input rod 6, that is, the relative displacement of the input rod 6 and the primary piston 2b by the drive motor 50.

  The brake booster 5 and the master cylinder pressure controller 8 displace the primary piston 2b according to the target deceleration determined by the amount of displacement of the input rod 6 due to the driver's brake operation. Thus, the primary hydraulic pressure chamber 2d is pressurized by the thrust of the primary piston 2b in addition to the thrust of the input rod 6, and the master cylinder pressure Pmc is adjusted. That is, the thrust of the input rod 6 is amplified. The amplification ratio (hereinafter referred to as the boost ratio α) is as follows according to the ratio of the axial cross-sectional areas (hereinafter referred to as pressure receiving areas AIR and APP, respectively) of the input rod 6 and the primary piston 2b in the primary hydraulic pressure chamber 2d. It is determined.

The hydraulic pressure of the master cylinder pressure Pmc is adjusted with a pressure equilibrium relationship represented by the following formula (1).
Pmc = (FIR + K × Δx) / AIR = (FPP−K × Δx) / APP (1)
Here, each element in the equation (1) indicating the pressure equilibrium relationship is as follows.
Pmc: Fluid pressure in the primary fluid pressure chamber 2d (master cylinder pressure)
FIR: thrust of input rod 6 FPP: thrust of primary piston 2b AIR: pressure receiving area of input rod 6 APP: pressure receiving area of primary piston 2b K: spring constant of springs 6d and 6e Δx: between input rod 6 and primary piston 2b Relative displacement amount In the first embodiment, the pressure receiving area AIR of the input rod 6 is set smaller than the pressure receiving area APP of the primary piston 2b.

  Here, the relative displacement amount Δx is defined as Δx = Xb−Xi, where Xi is the displacement of the input rod 6 (input rod stroke) and Xb is the displacement (piston stroke) of the primary piston 2b. Therefore, the relative displacement amount Δx is 0 at the neutral position of the relative movement, has a positive sign in the direction in which the primary piston 2b moves forward (strokes toward the positive direction of the x axis) with respect to the input rod 6, and has a negative sign in the opposite direction. . It should be noted that the sliding resistance of the seal is ignored in the equation (1) indicating the pressure equilibrium relationship. The thrust FPP of the primary piston 2b can be estimated from the current value of the drive motor 50.

On the other hand, the boost ratio α can be expressed as the following formula (2).
α = Pmc × (APP + AIR) / FIR (2)
Therefore, when Pmc of the above formula (1) is substituted into the formula (2), the boost ratio α is represented by the following formula (3).
α = (1 + K × Δx / FIR) × (AIR + APP) / AIR (3)
In the boost control, the drive motor 50 (piston stroke Xb) is controlled so that a target master cylinder pressure characteristic is obtained. Here, the master cylinder pressure characteristic refers to a change characteristic of the master cylinder pressure Pmc with respect to the input rod stroke Xi. Corresponding to the stroke characteristic indicating the piston stroke Xb with respect to the input rod stroke Xi and the target master cylinder pressure characteristic, it is possible to obtain a target displacement amount calculation characteristic indicating a change in the relative displacement amount Δx with respect to the input rod stroke Xi. Based on the target displacement amount calculation characteristic data obtained by the verification, a target value of the relative displacement amount Δx (hereinafter, target displacement amount Δx *) is calculated.

  That is, the target displacement amount calculation characteristic indicates a change characteristic of the target displacement amount Δx * with respect to the input rod stroke Xi, and one target displacement amount Δx * is determined corresponding to the input rod stroke Xi. When the rotation of the drive motor 50 (piston stroke Xb) is controlled so as to realize the target displacement amount Δx * determined corresponding to the detected input rod stroke Xi, a master cylinder having a size corresponding to the target displacement amount Δx * A pressure Pmc is generated in the master cylinder 2.

  Here, as described above, the input rod stroke Xi is detected by the brake operation amount detection device 7, the piston stroke Xb is calculated based on the signal of the rotation angle detection sensor 50a, and the relative displacement amount Δx is detected (calculated). It can be determined by the difference in quantity. In the boost control, specifically, the target displacement amount Δx * is set based on the input rod stroke Xi and the target displacement amount calculation characteristic, and the detected (calculated) relative displacement amount Δx is set as the target displacement amount Δx *. The drive motor 50 is controlled (feedback control) so as to match. A stroke sensor that detects the piston stroke Xb may be provided separately.

  In the first embodiment, since the boost control is performed without using the pedal force sensor, the cost can be reduced accordingly. Further, by controlling the drive motor 50 so that the relative displacement amount Δx becomes an arbitrary predetermined value, a boost ratio larger or smaller than the boost ratio determined by the pressure receiving area ratio (AIR + APP) / AIR is obtained. And a braking force based on a desired boost ratio can be obtained.

In the constant boost control, the input rod 6 and the primary piston 2b are integrally displaced, that is, the primary piston 2b is always in the neutral position with respect to the input rod 6, and is displaced with a relative displacement amount Δx = 0. The drive motor 50 is controlled.
Thus, when the primary piston 2b is stroked so that Δx = 0, the boost ratio α is uniquely determined as α = (AIR + APP) / AIR according to the above equation (3). Therefore, by setting AIR and APP based on the required boost ratio and controlling the primary piston 2b so that the piston stroke Xb becomes equal to the input rod stroke Xi, a constant (above required) boost ratio is always obtained. Can be obtained.

  The target master cylinder pressure characteristic in the constant boost control is that the master cylinder pressure Pmc generated as the input rod 6 moves forward (displacement in the positive direction of the x-axis) is a quadratic curve, a cubic curve, or more It becomes large in the form of a multi-order curve (hereinafter collectively referred to as a multi-order curve) in which higher-order curves are combined. The constant boost control has a stroke characteristic in which the primary piston 2b strokes by the same amount as the input rod stroke Xi (Xb = Xi). In the target displacement amount calculation characteristic obtained based on this stroke characteristic and the target master cylinder pressure characteristic, the target displacement amount Δx * is 0 for every input rod stroke Xi.

On the other hand, in the variable boost control, the target displacement amount Δx * is set to a predetermined positive value, and the drive motor 50 is controlled so that the relative displacement amount Δx becomes the predetermined value. Thus, the piston stroke Xb of the primary piston 2b becomes larger than the input rod stroke Xi as the input rod 6 moves forward in the direction of increasing the master cylinder pressure Pmc.
According to the above equation (3), the boost ratio α is (1 + K × Δx / FIR) times as large. That is, it is synonymous with the stroke of the primary piston 2b by an amount obtained by multiplying the input rod stroke Xi by a proportional gain (1 + K × Δx / FIR). In this way, the boost ratio α becomes variable according to the relative displacement amount Δx, and the brake booster 5 works as a boost source to generate a braking torque as required by the driver and greatly reduce the pedal effort. be able to.

From the viewpoint of controllability, the proportional gain (1 + K × Δx / FIR) is preferably 1. However, for example, when a braking torque exceeding the driver's brake operation amount is required due to emergency braking or the like, temporarily The proportional gain can be changed to a value greater than 1.
As a result, even with the same amount of brake operation, the master cylinder pressure Pmc can be increased as compared with the normal time (when the proportional gain is 1), so that a larger braking torque can be generated. Here, the emergency brake can be determined, for example, based on whether or not the time change rate of the signal of the brake operation amount detection device 7 exceeds a predetermined value.

  Thus, in the variable boost control, the forward movement of the primary piston 2b is further advanced with respect to the forward movement of the input rod 6. As a result, the relative displacement amount Δx of the primary piston 2b with respect to the input rod 6 increases as the input rod 6 advances, and the increase in the master cylinder pressure Pmc associated with the advancement of the input rod 6 correspondingly increases from the constant boost control. The drive motor 50 is controlled so as to be larger.

  In the target master cylinder pressure characteristic in the variable boost control, the increase in the master cylinder pressure Pmc that occurs as the input rod 6 moves forward (displacement in the positive x-axis direction) is larger than in the constant boost control (multiple order). Master cylinder pressure characteristics that increase in a curve become steeper). Further, the variable boost control has a stroke characteristic in which an increase in the piston stroke Xb with respect to an increase in the input rod stroke Xi is larger than 1. In the target displacement amount calculation characteristic obtained based on the stroke characteristic and the target master cylinder pressure characteristic, the target displacement amount Δx * increases at a predetermined rate as the input rod stroke Xi increases.

  Further, the variable boost control is the reverse of the above control (the control is such that the piston stroke Xb becomes larger than the input rod stroke Xi as the input rod 6 moves in the direction of increasing the master cylinder pressure Pmc). Also controls. That is, the drive motor 50 is controlled so that the piston stroke Xb becomes smaller than the input rod stroke Xi as the input rod 6 moves in the direction of increasing the master cylinder pressure Pmc. As a result, during regenerative cooperative control, the friction braking torque can be increased or decreased according to the increase or decrease of the regenerative braking torque.

[Processing of regenerative braking torque limit value setting unit]
FIG. 3 is a flowchart showing the flow of the regenerative braking torque limit value setting process in the regenerative braking torque limit value setting unit executed by the integrated controller 110.
That is, the regenerative braking torque limit value setting unit sets the regenerative braking torque limit value so that the pedaling force change amount and the vehicle deceleration fluctuation amount are within the allowable range with respect to the stepping-up operation of the brake pedal BP in the low vehicle speed range. FIG. 3 is a flowchart showing the processing flow.

This regenerative braking torque limit value setting process is started in response to the stepping on of the brake pedal BP being executed during a braking operation. In the first step S1, the previous regenerative braking torque limit value is set. Then, the process proceeds to step S2.
In the next step S2, the current regenerative braking torque limit value (without correction) is calculated, and then the process proceeds to step S3. This regenerative braking torque limit value (without correction) is a regenerative braking torque limit value that is not corrected or is not corrected to suppress the pedaling force fluctuation and vehicle deceleration fluctuation described later. The regenerative braking torque limit value (without correction) is set in advance with a map of the regenerative braking torque limit value for the vehicle speed in the low vehicle speed range where the switching control is performed, the vehicle speed is read, and the regenerative braking torque limit value according to the vehicle speed is set. Calculate the value (no correction).

  FIG. 4 shows an example of a map of the regenerative braking torque limit value used in step S2. In this regenerative braking torque limit value map, for each vehicle deceleration (G), a regenerative braking torque limit value corresponding to the vehicle speed is set, and the higher the vehicle deceleration, the lower the regenerative braking torque limit value. That is, the replacement start vehicle speed is set to be a high vehicle speed.

  In step S3, a pedal effort target value is calculated, and the process proceeds to step S4. The pedaling force target value is calculated by setting the pedaling force characteristic with respect to the input rod stroke Xi in advance and reading the input rod stroke Xi resulting from the additional pedaling. Further, as the characteristic of the pedal force target value with respect to the input rod stroke Xi, the static characteristic of the pedal force with respect to the input rod stroke Xi is acquired and set, for example, as a map as shown in FIG.

In step S4, after calculating the pedaling force value F1 without correction corresponding to the regenerative braking torque limit value (without correction), the process proceeds to step S5. The pedal force value F1 is calculated from the following formula (4) by calculating the relative position ΔX and the master cylinder pressure Pmc from the current regenerative braking torque limit value (without correction).
Treading force value without correction F1 = Pmc × AIR + K × Δx (4)
In the above equation (4), Pmc is the master cylinder pressure, AIR is the input rod area, K is the spring constant, and ΔX is the relative position of the primary piston 2b with respect to the input rod 6.

In step S5, the predicted treading force fluctuation value is calculated by the following equation (5), and then the process proceeds to step S6.
Predicted treading force fluctuation value = treading force value without correction (F1)-treading force target value (5)
In step S6, after calculating a pedaling force fluctuation allowable value, it progresses to step S7. Note that the allowable pedaling force fluctuation value is set in advance as an allowable pedaling force fluctuation value that does not give the driver an uncomfortable feeling based on the evaluation performed. Further, the pedaling force variation allowable value set in this way can be determined according to the input rod stroke Xi, the additional stroke amount, and the like.

In step S7, the predicted pedaling force fluctuation value is compared with the allowable pedaling force fluctuation value. If the predicted pedaling force fluctuation value is larger than the allowable pedaling force fluctuation value, the process proceeds to step S8 to limit the pedaling force fluctuation. If it is less than the allowable fluctuation value, the process proceeds to step S9.
In step S8, after calculating a regenerative braking torque limit value (after correction of treading force fluctuation) as a corrected regenerative braking torque limit value, the process proceeds to step S9.
In this step S8, when calculating the regenerative braking torque limit value (after correcting the pedaling force variation), first, the degree of change in the friction braking torque is calculated so that the predicted pedaling force variation and the allowable pedaling force variation are equal. Further, the degree of reduction of the regenerative braking torque is calculated from the degree of change of the friction braking torque. Then, based on the degree of decrease in the regenerative braking torque, the regenerative braking torque limit value (after correcting the pedaling force variation) in this control cycle is determined.

  In step S9, the vehicle deceleration target value is calculated, and then the process proceeds to step S10. The vehicle deceleration target value is calculated according to the input rod stroke Xi that has been read in advance by setting the vehicle deceleration characteristics with respect to the input rod stroke Xi. The vehicle deceleration characteristics with respect to the input rod stroke Xi are set, for example, by acquiring a deceleration target value characteristic (SG characteristic) map (see FIG. 8) for the input rod stroke Xi when the pedal is slowly depressed.

  In step S10, after calculating the vehicle deceleration without correction, that is, the vehicle deceleration when the regenerative braking torque limit value is not corrected for the braking operation, the process proceeds to step S11. The vehicle deceleration without correction is calculated from the regenerative braking torque limit value (without correction), the master cylinder pressure Pmc, vehicle specifications, brake specifications, and the like.

In step S11, after calculating the G fluctuation prediction value, the process proceeds to step S12. The predicted G fluctuation value is a predicted value of the vehicle deceleration fluctuation when the regenerative braking torque limit value (correction value) is used due to the pedaling force fluctuation caused by the additional operation of the brake pedal BP this time. 6).
G fluctuation predicted value = vehicle deceleration without correction−vehicle deceleration target (6)
In step S12, after calculating the G variation allowable value, the process proceeds to step S13. The G variation allowable value is set in advance to a value that does not give the driver a sense of incongruity based on the evaluation performed. Further, the G variation allowable value set in this way can also be determined based on the input rod stroke Xi, the stepping stroke amount, and the like.

  In step S13, the G fluctuation predicted value obtained in step S11 is compared with the G fluctuation allowable value obtained in step S12. If the G fluctuation predicted value is larger than the G fluctuation allowable value, occurrence of G fluctuation occurs. The process proceeds to step S14 in order to suppress this. On the other hand, if the predicted G fluctuation value is less than or equal to the allowable G fluctuation value, the process proceeds to step S15.

  In step S14, a regenerative braking torque limit value (after G variation correction) is calculated as a corrected regenerative braking torque limit value to which a limit for suppressing the G variation is added, and the process proceeds to the next step S15. In this step S14, the regenerative braking torque limit value (after G fluctuation correction) is calculated first by considering the response speed of the friction braking torque so that the predicted G fluctuation value and the allowable G fluctuation value are equal. The degree of change is calculated. Further, a reduction degree of the regenerative braking torque corresponding to the change degree of the friction braking torque is calculated. Then, based on the degree of decrease in the regenerative braking torque, the regenerative braking torque limit value (after G variation correction) in the current control cycle is determined.

  In step S15, after calculating the final regenerative braking torque limit value, the current process is terminated. The final regenerative braking torque limit value is compared with the regenerative braking torque limit value (without correction), the regenerative braking torque limit value (after correction of treading force fluctuation), and the regenerative braking torque limit value (after correction of G fluctuation). The largest value is calculated as the final regenerative braking torque limit value.

(Operation of Embodiment 1)
Next, an operation example of the vehicle brake control device according to the first embodiment will be described. First, an operation example of a comparative example corresponding to the technique described in Patent Document 1 and its problems will be described.
(Comparative example)
FIG. 5 shows an example of the operation of the comparative example.
In the comparative example of FIG. 5, the braking operation is performed and the vehicle speed Vw decreases to the switching threshold value V0 at which switching control is started, and switching control between the regenerative braking torque and the friction braking torque is started from time t01.
Then, the driver increases the amount of depression (pedal stroke) of the brake pedal from Spa to Spb at time t02 in the low speed range where such switching control is performed.

  In this case, the limit value of the regenerative braking torque is based on the map of FIG. A regenerative braking torque limit value Trlima corresponding to the vehicle speed at aG is calculated. When the pedal stroke amount Spb is operated, the deceleration 0. A regenerative braking torque limit value Trlimb corresponding to the vehicle speed at eG is calculated.

  Due to this regenerative braking torque limitation, as shown in FIG. 5, the regenerative braking torque suddenly decreases at the time t02, and the amount of increase and the brake pedal BP corresponding to the sudden decrease in the regenerative braking torque are depressed. The friction braking torque is increased by adding the minutes.

Therefore, the decrease in the regenerative braking torque immediately appears in the vehicle deceleration, and as shown in FIG. 5, the vehicle deceleration fluctuation (G fluctuation) in which the vehicle deceleration rapidly decreases occurs.
Then, the master cylinder pressure Pmc rapidly increases slightly after the G fluctuation. For this reason, the fluctuation of the master cylinder pressure Pmc is transmitted to the brake pedal BP via the input rod 6, and the pedaling force fluctuation occurs.
Therefore, there is a problem that the driver feels uncomfortable due to the G variation that reduces the vehicle deceleration and also feels uncomfortable due to the variation in the pedaling force even though the brake pedal BP is stepped on.

(Operation of Embodiment 1)
The vehicular braking control apparatus of the first embodiment suppresses the above-described G fluctuation and pedaling force fluctuation, and the operation when the stepping-up operation similar to that in FIG. 5 is performed will be described with reference to FIG.
Even in the operation example of FIG. 6, the braking operation is performed and the vehicle speed Vw is lowered to the switching threshold value V0 for starting the switching control, and the switching control between the regenerative braking torque and the friction braking torque is started from the time t1. ing.
Then, in the low speed range where such switching control is performed, the driver performs a stepping operation to increase the depression amount (pedal stroke Sp) of the brake pedal BP from Spa to Spb at the time t2.

  Also in this case, the regenerative braking torque limit value (without correction) is determined based on the map of FIG. aG, Trlima according to vehicle speed, pedal stroke amount Spb, vehicle deceleration 0. eG is changed to Trlimb corresponding to the vehicle speed.

With this change in the limit value of the regenerative braking torque, in the comparative example, as shown in FIG. 5, the regenerative braking torque suddenly decreased at the time t02, but in the first embodiment, the process of step 8 in FIG. The regenerative braking torque limit value is given a reduction limit based on the pedaling force fluctuation allowable value.
That is, when the predicted pedaling force fluctuation value due to the additional depression of the brake pedal BP exceeds the allowable pedaling force fluctuation value, the degree of change in the friction braking torque is calculated so that the predicted pedaling force fluctuation value is equal to the allowable pedaling force fluctuation value. Further, the reduction degree of the regenerative braking torque is calculated from the change degree of the friction braking torque. Based on the degree of decrease in the regenerative braking torque, a regenerative braking torque limit value (after correcting the treading force variation) is calculated. Here, the predicted pedaling force fluctuation value is, for example, a value corresponding to the pedaling force fluctuation shown in FIG. Further, the pedaling force fluctuation allowable value is a value corresponding to the pedaling force fluctuation range indicated by Lp in FIG.

Furthermore, in the first embodiment, a limit based on the G fluctuation allowable value is given to the regenerative braking torque limit value based on the process of step S14 in FIG.
That is, when the predicted G fluctuation value due to the additional depression of the brake pedal BP exceeds the allowable G fluctuation value, the degree of change in the friction braking torque at which the predicted G fluctuation value and the allowable G fluctuation value are equal is calculated. Further, the reduction degree of the regenerative braking torque is calculated from the change degree of the friction braking torque. Then, based on the degree of decrease in the regenerative braking torque, a regenerative braking torque limit value (after G variation correction) is calculated. Here, the G fluctuation predicted value is, for example, a value corresponding to the G fluctuation shown in FIG. Further, the G variation allowable value is a value corresponding to the G variation range indicated by Lg in FIG.

In this operation example, the larger value of the regenerative braking torque limit value (after correction of treading force fluctuation) and the regenerative braking torque limit value (after correction of G fluctuation) is set as the final regenerative braking torque.
As a result, the degree of change in the regenerative braking torque is reduced from the time t2 to the time t3, as shown in FIG. 6, based on either the treading force variation allowable value or the G variation allowable value. Gradually decreases.
In addition, the friction braking torque also rises more gently with the degree of change being reduced as the regenerative braking torque decreases, compared to the comparative example indicated by the dotted line in FIG.

  Therefore, in the first embodiment, immediately after the time point t2, the sudden decrease in the regenerative braking torque as in the comparative example is eliminated, so that the fluctuation in the longitudinal acceleration (G) indicated by the dotted line in the figure is suppressed (improved). The In addition, the sudden increase in the friction braking torque that is delayed from the regenerative braking torque is eliminated, and this variation is a variation that is limited to the pedaling force variation allowable value, so the variation in the comparative example shown by the dotted line in FIG. It is suppressed (improved) in comparison.

(Effect of Embodiment 1)
In the vehicle brake control device of the first embodiment, the following effects can be obtained.
1) The vehicle braking control apparatus of Embodiment 1
An input rod 6 as an input member that moves forward and backward by the operation of the brake pedal BP, a primary piston 2b as an assist member provided so as to be relatively movable with respect to the moving direction of the input rod 6, and the primary piston 2b Springs 6d and 6e as urging members for urging the input rod 6 toward the neutral position of both relative displacements, and a drive motor 50 as an actuator for moving the primary piston 2b forward and backward according to the amount of movement of the input rod 6 A brake booster 5 for generating a master cylinder pressure Pmc boosted in the master cylinder 2 by the thrust of the primary piston 2b,
Wheel cylinders 4a to 4d as friction braking devices for applying friction braking torque to the wheels according to the master cylinder pressure Pmc;
A motor generator MG as a regenerative braking device for applying a regenerative braking torque to the wheel;
As a regenerative cooperative controller that executes regenerative cooperative control for controlling the friction braking torque and the regenerative braking torque so that a total braking torque including the friction braking torque and the regenerative braking torque becomes a driver's required braking torque. An integrated controller 110, a motor controller 102, a brake controller 109,
With
The regenerative coordination controller includes a regenerative braking torque limit value setting unit (a part for executing the processing of the flowchart of FIG. 3) that sets a regenerative braking torque limit value in accordance with a braking operation, and the regenerative braking is performed during the regenerative coordination control. A vehicular braking control device configured to limit the regenerative braking torque by a torque limit value,
The regenerative braking torque limit value setting unit, when changing the regenerative braking torque limit value in accordance with a change in brake pedal operation amount, includes at least a pedaling force change amount and a vehicle deceleration change amount after the regenerative braking torque limit value change. It is determined whether one is within the allowable range, and when the allowable range is exceeded, the corrected regenerative braking torque limit value corrected so that the amount of change is within the allowable range is used as the regenerative braking torque limit value. Is calculated.
Therefore, when the regenerative braking torque limit value is changed according to the driver's brake pedal depressing operation, the pedal force change amount after the regenerative braking torque limit value change and the vehicle deceleration change amount after the regenerative braking torque limit value change are It is determined whether at least one of the values is within the set allowable range. Then, if the allowable range is exceeded, the corrected regenerative braking torque limit value whose variation is within the allowable range is calculated as the regenerative braking torque limit value.
Therefore, the regenerative cooperative controller sets the regenerative braking torque at the time of switching control within the allowable range of the change amount of at least one of the pedal force change amount and the vehicle deceleration change amount before and after the stepping operation by the corrected regenerative braking torque limit value. Can be suppressed.

2) The vehicle braking control device of the first embodiment is
The regenerative braking torque limit value setting unit (the portion that executes the process of the flowchart of FIG. 3) sets the first correction regenerative braking torque limit value that makes the pedaling force change amount after the regenerative braking torque limit value change within the allowable range. Regenerative braking torque limit value (after correction of treading force fluctuation) and regenerative braking torque as the second corrected regenerative braking torque limit value that makes the vehicle deceleration change amount after the regenerative braking torque limit value change within the allowable range Both the limit value (after G variation correction) is calculated, and the final regenerative braking torque limit value is set based on both corrected regenerative braking torque limit values.
Therefore, both the pedaling force change amount and the vehicle deceleration change amount can be suppressed.
In particular, in the first embodiment, the larger value of the regenerative braking torque limit value (after correction of treading force fluctuation) and the regenerative braking torque limit value (after correction of G fluctuation) is set as the final regenerative braking torque limit value. Both the pedaling force change amount and the vehicle deceleration change amount can be reliably suppressed.

3) The vehicle braking control device of the first embodiment is
The regenerative braking torque limit value setting unit (the portion that executes the processing of the flowchart of FIG. 3) calculates a predicted treading force fluctuation value based on the braking operation based on the braking operation and the regenerative braking torque limit value before correction. When the calculated pedaling force fluctuation predicted value exceeds a preset pedaling force fluctuation allowable value, the degree of change in the frictional braking torque is calculated so that the two are equal, and the calculated frictional braking torque is calculated. Based on the degree of change, the reduction degree of the regenerative braking torque is calculated, and based on the reduction degree of the regenerative braking torque, the regenerative braking torque limit value (after correction of the treading force variation) is determined as the corrected regenerative braking torque limit value. The process of steps S7 → S8 is executed.
In this way, the pedaling force variation due to the regenerative braking torque limit value when correction is not performed is predicted, and when the predicted value exceeds the pedaling force variation allowable value, the regenerative braking torque limit value (after the pedaling force variation correction) is calculated. Then, the regenerative braking torque limit value (after correcting the pedaling force fluctuation) calculates the degree of change of the friction braking torque so that the pedaling force fluctuation falls within the allowable pedaling force fluctuation value, and further regenerates based on the degree of change of the friction braking torque. The degree of change in braking torque is calculated. Accordingly, the regenerative braking torque limit value (after correcting the pedaling force fluctuation) determined based on the degree of change of the regenerative braking torque can reliably suppress the pedaling force fluctuation within the pedaling force fluctuation allowable value.

4) The vehicle brake control device of the first embodiment is
The regenerative braking torque limit value setting unit (the part that executes the processing of the flowchart of FIG. 3) determines the deceleration fluctuation predicted value based on the braking operation based on the braking operation and the regenerative braking torque limit value before correction. If the predicted deceleration fluctuation value exceeds a preset allowable deceleration value, the degree of change in the friction braking torque considering the response speed is calculated so that both are equal, A process of steps S13 → S14 is performed in which a reduction degree of the regenerative braking torque is calculated based on a change degree of the friction braking torque, and the correction regenerative braking torque is calculated based on the reduction degree of the regenerative braking torque. To do.
Thus, the vehicle deceleration fluctuation due to the regenerative braking torque limit value when correction is not performed is predicted, and the regenerative braking torque limit value (after G fluctuation correction) is calculated when the predicted value exceeds the allowable deceleration value. To do. Then, the regenerative braking torque limit value (after G variation correction) is calculated by calculating the degree of change of the friction braking torque in consideration of the response speed so that the deceleration variation is within the allowable deceleration value. The degree of decrease in regenerative braking torque is calculated based on the degree of change in. Therefore, the regenerative braking torque limit value (after correcting the G fluctuation) determined based on the degree of change of the regenerative braking torque can reliably suppress the vehicle deceleration fluctuation within the allowable deceleration value.

  As mentioned above, although the vehicle brake control apparatus of the present invention has been described based on the embodiment, the specific configuration is not limited to this embodiment, and the invention according to each claim of the claims. Design changes and additions are permitted without departing from the gist of the present invention.

For example, in the embodiment, an example in which the vehicle brake control device of the present invention is applied to a rear-wheel drive hybrid vehicle has been described. However, the vehicle brake control device of the present invention may be applied to a front-wheel drive, all-wheel drive electric vehicle, a hybrid vehicle, or a fuel cell vehicle as long as the vehicle switches between regenerative braking torque and friction braking torque. it can.
In the embodiment, the regenerative braking torque limit value setting unit sets the regenerative braking torque limit value as the first corrected regenerative braking torque limit value that sets the pedaling force change amount after changing the regenerative braking torque limit value within the allowable range. (After correction of treading force fluctuation) and regenerative braking torque limit value (after correction of G fluctuation) as a second corrected regenerative braking torque limit value in which the amount of change in vehicle deceleration after changing the regenerative braking torque limit value is within the allowable range However, the present invention is not limited to this, and only one of the first corrected regenerative braking torque limit value and the second corrected regenerative braking torque limit value is calculated. Also good. Further, even when one of the pedal force fluctuation and the vehicle deceleration fluctuation is suppressed in this way, the other fluctuation can be suppressed by suppressing the decrease in the regenerative braking torque limit value.

2 Master cylinder 2b Primary piston (assist member)
4a to 4d Foil cylinder (friction braking device)
6 Input rod (input member)
6d Spring (biasing member)
6e Spring (biasing member)
50 Drive motor (actuator)
102 Motor controller (regenerative cooperative controller)
109 Brake controller (regenerative cooperative controller)
110 Integrated controller (regenerative cooperative controller)
BP Brake pedal MG Motor generator (regenerative braking device)

Claims (4)

An input member that moves forward and backward by the operation of the brake pedal, an assist member that is movable relative to the direction of movement of the input member, and the input member is directed toward the neutral position of the relative displacement of the assist member. An urging member that urges the input member and an actuator that moves the assist member forward and backward according to the amount of movement of the input member, and generates a master cylinder pressure boosted in the master cylinder by the thrust of the assist member. A brake booster,
A friction braking device for applying a friction braking torque to the wheel according to the master cylinder pressure;
A regenerative braking device for applying a regenerative braking torque to the wheel;
A regenerative cooperative controller that executes regenerative cooperative control for controlling the friction braking torque and the regenerative braking torque so that a total braking torque including the friction braking torque and the regenerative braking torque becomes a driver's required braking torque;
With
The regenerative coordination controller includes a regenerative braking torque limit value setting unit that sets a regenerative braking torque limit value in accordance with a braking operation, and limits the regenerative braking torque by the regenerative braking torque limit value during the regenerative coordination control. A vehicle brake control device,
The regenerative braking torque limit value setting unit, when changing the regenerative braking torque limit value in accordance with a change in brake pedal operation amount, includes at least a pedaling force change amount and a vehicle deceleration change amount after the regenerative braking torque limit value change. It is determined whether one is within the allowable range, and when the allowable range is exceeded, the corrected regenerative braking torque limit value corrected so that the amount of change is within the allowable range is used as the regenerative braking torque limit value. A braking control device for a vehicle, characterized in that The vehicle brake control device according to claim 1,
The regenerative braking torque limit value setting unit includes a first correction regenerative braking torque limit value that sets a pedaling force change amount after changing the regenerative braking torque limit value within the allowable range, and a vehicle decrease after changing the regenerative braking torque limit value. A second regenerative braking torque limit value that sets a speed change amount within the allowable range is calculated, and a final regenerative braking torque limit value is set based on both corrected regenerative braking torque limit values. A vehicle brake control device. In the vehicle brake control device according to claim 1 or 2,
The regenerative braking torque limit value setting unit calculates a predicted pedaling force fluctuation value based on the braking operation based on the braking operation and the regenerative braking torque limit value before the correction, and the predicted pedaling force fluctuation value is preset. The degree of change in the friction braking torque is calculated so that both are equal, and the degree of decrease in the regenerative braking torque is calculated based on the calculated degree of change in the friction braking torque. A vehicular braking control apparatus that determines the correction regenerative braking torque limit value based on a reduction degree of the regenerative braking torque. In the vehicle brake control device according to claim 1 or 2,
The regenerative braking torque limit value setting unit calculates a deceleration fluctuation predicted value based on the braking operation based on the braking operation and the regenerative braking torque limit value before correction, and the deceleration fluctuation predicted value is calculated in advance. When exceeding the set deceleration allowable value, the degree of change of the friction braking torque is calculated in consideration of the response speed so that both are equal, and the degree of reduction of the regenerative braking torque is calculated based on the degree of change of the friction braking torque. A vehicular braking control apparatus that calculates and calculates the corrected regenerative braking torque based on the regenerative braking torque reduction degree.