JP2001039287A - Brake fluid pressure control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of a plate braking sense during antiskid control, by prolonging a pressure increasing time for increasing pulse pressure compared with unloosening brake stepping force when loosening the force is judged by a stepping force loosening judging means. SOLUTION: Antiskid control having conditioned brake fluid pressure is performed by designating a control mode to a fluid pressure control device 2 when wheel lock is detected by an electronic control device 10. When pumping brake action, for immediately stepping a brake again after loosening brake stepping force once, is made during antiskid control, a stepping force loosening judging means judges loosening brake stepping force, which is a precursory phenomenon for pumping brake action, based on output signals from liquid pressure detecting means 46 and 47; then the control mode is switched to a stepping force loosening corresponding pulse pressure increasing mode, having a pressure increasing time longer than that in a normal pulse pressure increasing mode, based on the judgement. Consequently the shutout time for a master cylinder 2a and wheel cylinders 51-54 can be shortened, to prevent a plate brake sense.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle brake fluid pressure control device, and more particularly to an anti-skid control device (AB).
S control device).

[0002]

2. Description of the Related Art As a vehicle brake fluid pressure control device,
In order to prevent the wheels from locking during sudden braking, the brake fluid pressure applied to the wheel cylinders of each wheel is reduced, increased, or maintained to maximize the coefficient of friction between the road surface and the wheels. A motor having an anti-skid control device for controlling power is widely used.

In such an anti-skid control device,
It monitors whether the wheel acceleration (wheel deceleration) is equal to or higher than a predetermined threshold value, and whether the slip ratio obtained based on the wheel speed and the vehicle speed is equal to or higher than a predetermined threshold value. The wheel lock is detected, and anti-skid control is performed.

[0004]

However, in such an anti-skid control device, when the brake depressing force applied to the brake pedal is reduced during the anti-skid control and a pumping brake operation in which the brake pedal is immediately depressed is performed, The pulse pressure increase mode consisting of a combination of pressure increase and pressure holding is selected. In this case, since the communication between the hydraulic pressure generating device, that is, the master cylinder and the wheel cylinder is interrupted during the pressure holding, the consumption of the brake fluid due to the operation of the brake pedal is small, and the driver feels a so-called plate brake feeling. As a result, it is difficult to control the braking force.

The present invention has been made in view of such a conventional problem, and provides a brake fluid pressure control device that does not generate a feeling of plate brake even when a pumping brake operation is performed during anti-skid control. The purpose is to:

[0006]

According to a first aspect of the present invention, there is provided a brake fluid pressure control device mounted on each wheel of a vehicle to apply a braking force to the wheel. A wheel cylinder, a hydraulic pressure generating device for supplying brake hydraulic pressure to the wheel cylinder, a brake pedal connected to the hydraulic pressure generating device for transmitting a braking operation of a driver to the hydraulic pressure generating device, A hydraulic pressure detecting means for detecting a generated hydraulic pressure of the generating device; a hydraulic pressure control device disposed between the hydraulic pressure generating device and the wheel cylinder to control a brake hydraulic pressure of the wheel cylinder; Wheel speed detecting means for detecting the wheel speed of the vehicle, wheel speed calculating means for calculating the wheel speed from the output signal of the wheel speed detecting means, and wheel acceleration for calculating the wheel acceleration of each wheel from the wheel speed Calculating means, an estimated vehicle speed calculating means for calculating the vehicle speed based on the wheel speed, and a braking force for controlling the braking force by driving the hydraulic pressure control device according to the wheel speed, the wheel acceleration and the estimated vehicle speed. A brake pressure control device comprising: a pressure reducing mode for reducing a hydraulic pressure applied to the wheel cylinder; a pulse pressure increasing mode including a combination of pressure increasing and holding; Control mode setting means for setting a holding mode for holding the hydraulic pressure applied to the cylinder, and detecting the hydraulic pressure when the braking force control means drives the hydraulic pressure control device to control the braking force. Means for determining whether or not the brake pedal force applied to the brake pedal has been reduced based on the output signal of the means. When it is determined that because, compared to the case where the brake pedal force is not loosened,
It is characterized in that the pressure increasing time of the pulse pressure increasing is lengthened.

In the invention according to the first aspect, when a brake operation is performed, the brake fluid pressure generated in the fluid pressure generating device is adjusted by the fluid pressure control device, and is applied to the wheel cylinder to apply a braking force to the wheel. Granted. That is, the wheel speed calculated by the wheel acceleration calculating means based on the wheel speed calculated by the wheel speed calculating means from the output signal of the wheel speed detecting means, the estimated vehicle body speed calculated by the estimated vehicle speed calculating means, and the wheel speed. From the acceleration, the braking force control means determines whether or not the wheel acceleration (wheel deceleration) is equal to or greater than a predetermined threshold value, and determines whether the slip rate determined based on the wheel speed and the estimated vehicle speed is a predetermined threshold value. The brake fluid pressure is adjusted by determining whether or not the above is true, detecting wheel lock, and instructing the fluid pressure control device to control the pressure reduction, holding, pressure increase or a combination thereof. Anti-skid control is performed.

In the case where the brake pedal force applied to the brake pedal is relaxed during the anti-skid control and a pumping brake operation is performed in which the brake pedal is immediately depressed again, the pedal force loosening judging means judges based on the output signal of the hydraulic pressure detecting means. It is determined whether the brake depression force, which is a precursor of the pumping brake operation, is relaxed. Based on the determination, the mode is switched to the pulse pressure increasing mode corresponding to the depression of the pedaling force where the pressure increasing time is longer than the normal pulse pressure increasing mode. Therefore, the shut-off time between the master cylinder and the wheel cylinder is reduced, and the feeling of plate brake is prevented. .

Next, as set forth in claim 2, a wheel cylinder mounted on each wheel of a vehicle to apply a braking force to the wheel, a hydraulic pressure generating device for supplying a brake hydraulic pressure to the wheel cylinder, A brake pedal connected to the hydraulic pressure generating device and transmitting a braking operation of a driver to the hydraulic pressure generating device; a hydraulic pressure detecting means for detecting a generated hydraulic pressure of the hydraulic pressure generating device; A hydraulic pressure control device disposed between the vehicle and the wheel cylinder for controlling a brake hydraulic pressure of the wheel cylinder, a wheel speed detecting means for detecting a wheel speed of each wheel, and an output signal of the wheel speed detecting means Wheel speed calculating means for calculating the wheel speed from
Wheel acceleration calculating means for calculating the wheel acceleration of each wheel from the wheel speed; estimated vehicle speed calculating means for calculating the vehicle speed based on the wheel speed; and the vehicle speed based on the wheel speed, the wheel acceleration and the estimated vehicle speed. A brake pressure control device for controlling a braking force by driving a pressure control device, wherein the braking force control device includes: a pressure reduction mode for reducing a hydraulic pressure applied to the wheel cylinder; And a control mode setting means for setting a holding mode for holding the hydraulic pressure applied to the wheel cylinders, and the braking force control means drives the hydraulic pressure control device. It is determined whether or not the brake depression force applied to the brake pedal has been relaxed based on the output signal of the hydraulic pressure detection means while controlling the braking force It is preferable that the brake fluid pressure control device further includes a force loosening determining unit, and when the pedaling force loosening determining unit determines that the pedaling force is loosened, the braking force control unit immediately stops controlling the braking force. .

[0010] In the invention according to the second aspect, when the brake pedal force applied to the brake pedal is relaxed during the anti-skid control and a pumping brake operation for immediately re-stepping is performed, the pedal force loosening determination means detects the hydraulic pressure. Based on the output signal of the means, it is determined whether the brake depression force, which is a precursor of the pumping brake operation, is relaxed. On the basis of the determination, the braking force control means immediately stops the braking force control and returns to the normal brake, so that the master cylinder and the wheel cylinder are communicated with each other, so that a feeling of plate brake is prevented.

Next, as set forth in claim 3, a wheel cylinder mounted on each wheel of the vehicle to apply a braking force to the wheel, a hydraulic pressure generating device for supplying a brake hydraulic pressure to the wheel cylinder, A brake pedal connected to the hydraulic pressure generating device and transmitting a braking operation of a driver to the hydraulic pressure generating device; a hydraulic pressure detecting means for detecting a generated hydraulic pressure of the hydraulic pressure generating device; A hydraulic pressure control device disposed between the vehicle and the wheel cylinder for controlling a brake hydraulic pressure of the wheel cylinder, a wheel speed detecting means for detecting a wheel speed of each wheel, and an output signal of the wheel speed detecting means Wheel speed calculating means for calculating the wheel speed from
Wheel acceleration calculating means for calculating the wheel acceleration of each wheel from the wheel speed; estimated vehicle speed calculating means for calculating the vehicle speed based on the wheel speed; and the vehicle speed based on the wheel speed, the wheel acceleration and the estimated vehicle speed. A brake pressure control device for controlling a braking force by driving a pressure control device, wherein the braking force control device includes: a pressure reduction mode for reducing a hydraulic pressure applied to the wheel cylinder; And a control mode setting means for setting a holding mode for holding the hydraulic pressure applied to the wheel cylinders, and the braking force control means drives the hydraulic pressure control device. It is determined whether or not the brake depression force applied to the brake pedal has been relaxed based on the output signal of the hydraulic pressure detection means while controlling the braking force A brake fluid pressure control device comprising force loosening determining means, wherein when the pedaling force loosening determining means determines that the pedaling force is loosened, the braking force control means immediately stops controlling the braking force of the front wheels. Is preferred.

In the invention according to claim 3, when the pumping brake operation in which the brake pedal force applied to the brake pedal is reduced during the anti-skid control and the vehicle is immediately depressed again is performed, the pedal force release determination means detects the hydraulic pressure. Based on the output signal of the means, it is determined whether the brake depression force, which is a precursor of the pumping brake operation, is relaxed. Based on the determination, the braking force control means immediately stops the control of the braking force of the front wheels and returns to normal braking. The communication with the cylinder prevents the feeling of plate brake.

Next, as set forth in the fourth aspect, the stepping force loosening determining means determines that the maximum value of the brake hydraulic pressure detected by the hydraulic pressure detecting means is equal to or greater than a first predetermined value, and It is preferable to determine that the pedaling force has been relaxed when the brake fluid pressure after a lapse of a predetermined time from the time at which the maximum value has occurred becomes smaller by a second predetermined value than the maximum value of the brake fluid pressure. Thereby, the maximum value of the brake fluid pressure is constantly monitored, and when the brake fluid pressure decreases by a predetermined value within a predetermined time from the time when the maximum value of the brake fluid pressure is generated, it is determined that the brake pedal force is reduced. That is, it is possible to quickly determine the precursor of the pumping brake operation.

Next, as set forth in claim 5, the stepping force loosening determining means determines that the brake hydraulic pressure detected by the hydraulic pressure detecting means is equal to or higher than a first predetermined value and that the brake hydraulic pressure is equal to the first predetermined value. It is preferable to determine that the brake depression force has been relaxed when the brake fluid pressure after a lapse of a predetermined time from the time at which the brake pressure has exceeded the predetermined value becomes equal to or lower than a second predetermined value smaller than the first predetermined value. Accordingly, when the brake fluid pressure drops to the second predetermined value within a predetermined time after the brake fluid pressure becomes equal to or higher than the first predetermined value, it is determined that the brake pedal effort has been relaxed, and a sign of the pumping brake operation is quickly given. Can be determined.

[0015] Next, as set forth in claim 6, the stepping force loosening judging means judges that the hydraulic pressure detecting means has detected the brake fluid pressure at a first predetermined time and that a predetermined time has elapsed from the first predetermined time. It is preferable to determine that the brake depression force has been relaxed when a value obtained by dividing a difference from the brake fluid pressure detected at a second predetermined time later by a predetermined time becomes equal to or less than a predetermined value (negative value). As a result, even when the brake fluid pressure is equal to or less than the predetermined value, if the time change of the brake fluid pressure is equal to or more than the predetermined value, it can be determined that the rake pedal effort has been relaxed, and the precursor of the pumping brake operation can be quickly determined. Becomes possible.

Next, as set forth in claim 7, a wheel cylinder mounted on each wheel of the vehicle to apply a braking force to the wheel, a hydraulic pressure generating device for supplying a brake hydraulic pressure to the wheel cylinder, A brake pedal connected to the hydraulic pressure generating device and transmitting a braking operation of a driver to the hydraulic pressure generating device; a hydraulic pressure detecting means for detecting a generated hydraulic pressure of the hydraulic pressure generating device; A hydraulic pressure control device disposed between the vehicle and the wheel cylinder for controlling a brake hydraulic pressure of the wheel cylinder, a wheel speed detecting means for detecting a wheel speed of each wheel, and an output signal of the wheel speed detecting means Wheel speed calculating means for calculating the wheel speed from
Wheel acceleration calculating means for calculating the wheel acceleration of each wheel from the wheel speed; estimated vehicle speed calculating means for calculating the vehicle speed based on the wheel speed; and the vehicle speed based on the wheel speed, the wheel acceleration and the estimated vehicle speed. A brake pressure control device for controlling a braking force by driving a pressure control device, wherein the braking force control device includes: a pressure reduction mode for reducing a hydraulic pressure applied to the wheel cylinder; And a control mode setting means for setting a holding mode for holding the hydraulic pressure applied to the wheel cylinders, and the braking force control means drives the hydraulic pressure control device. It is determined whether or not the brake depression force applied to the brake pedal has been relaxed based on the output signal of the hydraulic pressure detection means while controlling the braking force Force-relaxation determining means, and re-stepping-on determining means for determining whether or not brake depressing force applied to the brake pedal based on the output signal of the hydraulic pressure detecting means has been relaxed and brake depressing force has been applied again after a predetermined time has elapsed. It is preferable that the brake fluid pressure control device further comprises: when the re-stepping-on determining means determines that the vehicle is stepping on again, the holding time in the pulse pressure increase is set to zero.

In the invention according to claim 7, when the brake pedal force applied to the brake pedal is relaxed during the anti-skid control and a pumping brake operation for immediately re-stepping is performed, the re-stepping determination means determines the brake pedal force. Determine that it has been added again. When the re-stepping-on determination means determines that the vehicle is stepping on again, only the pressure increase is performed with the holding time in the pulse pressure increase to be zero, thereby preventing the master cylinder from being disconnected from the wheel cylinder, thereby preventing the feeling of plate brake.

[0018] Next, as set forth in claim 8, the pedaling force loosening determining means determines that the maximum value of the brake hydraulic pressure detected by the hydraulic pressure detecting means is equal to or greater than a first predetermined value, and It is preferable to determine that the pedaling force has been relaxed when the brake fluid pressure after a lapse of a predetermined time from the time at which the maximum value has occurred becomes smaller by a second predetermined value than the maximum value of the brake fluid pressure. Thereby, the maximum value of the brake fluid pressure is constantly monitored, and when the brake fluid pressure decreases by a predetermined value within a predetermined time from the time when the maximum value of the brake fluid pressure is generated, it is determined that the brake pedal force is reduced. That is, it is possible to quickly determine the precursor of the pumping brake operation.

Next, as set forth in the ninth aspect, the pedaling force loosening determining means includes a brake fluid pressure detected by the hydraulic pressure detecting means being equal to or greater than a first predetermined value, and When the brake fluid pressure after a lapse of a predetermined time from the time when the brake fluid pressure has become equal to or greater than the first predetermined value becomes equal to or less than a second predetermined value smaller than the first predetermined value, it is determined that the pedaling force has been relaxed. Is preferred. Thus, after the brake fluid pressure becomes equal to or higher than the first predetermined value, the second
When the pressure decreases to a predetermined value, it is determined that the brake depression force has been relaxed, and it is possible to quickly determine a precursor of the pumping brake operation.

Next, as set forth in the tenth aspect, the stepping force loosening determining means includes a brake fluid pressure detected by the fluid pressure detecting means at a first predetermined time and a predetermined time elapsed from the first predetermined time. It is preferable to determine that the pedaling force has been relaxed when a value obtained by dividing a difference from the brake fluid pressure detected at a second predetermined time later by a predetermined time becomes equal to or less than a predetermined value. As a result, even when the brake fluid pressure is equal to or less than the predetermined value, if the time change of the brake fluid pressure is equal to or more than the predetermined value, it can be determined that the rake pedal effort has been relaxed, and the precursor of the pumping brake operation can be quickly determined. Becomes possible.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a brake fluid pressure control device according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a brake fluid pressure control device according to an embodiment of the present invention, in which a master cylinder 2a and a booster 2 are provided.
b, hydraulic pressure generating device 2 driven by brake pedal 3, right front wheel FR, left front wheel FL, right rear wheel RR, left rear wheel RL
The pumps 21 and 22, the reservoir 23, and the hydraulic passage to which each of the wheel cylinders 51 to 54 disposed
24 and solenoid valves 31 to 38 are provided.

An actuator (hydraulic pressure control device) 30 is provided between the hydraulic pressure generating device 2 and the wheel cylinders 51 to 54.
Are arranged. The actuator 30 is connected to one output port of the master cylinder 2a and the wheel cylinder 5
Solenoid valves 31, 3
2, 33 and 34 are arranged, and these and master cylinder 2
The pump 21 is provided between the pump 21 and the pump 21. Similarly, the solenoid valves 35, 3 are connected to the hydraulic passage connecting the other output port of the master cylinder 2a and each of the wheel cylinders 52, 53.
6, 37 and 38 are arranged, and these and master cylinder 2
The pump 22 is disposed between the pump 22 and the valve 22a. Pump 21,
The motor 22 is driven by the electric motor 20, and the above-mentioned hydraulic pressure path is supplied with a brake hydraulic pressure raised to a predetermined pressure.

The discharge hydraulic passages of the normally closed solenoid valves 32 and 34 are connected to the pump 21 via a reservoir 23. Similarly, the discharge hydraulic passages of the normally closed solenoid valves 36 and 38 are connected to the discharge hydraulic passages. , Is connected to the pump 22 via a reservoir 24. The reservoirs 23 and 24 each include a piston and a spring,
The brake fluid that is recirculated from the solenoid valves 32, 34, 36, and 38 via the discharge-side hydraulic path is housed, and the pump 2
The brake fluid is supplied at the time of the operation of 1,22.

The solenoid valves 31 to 38 are two-port, two-position solenoid valves. When the solenoid is not energized (hereinafter referred to as off), the wheel cylinders 51 to 54 are connected to the hydraulic pressure generator 2 and the pump 21, 22. When the solenoid is energized (hereinafter referred to as ON), the wheel cylinders 51 to 54 are connected to the hydraulic pressure generator 2 and the pump 2
1 and 22, and communicate with the reservoirs 23 and 24. The check valve permits only the flow of the brake fluid from the wheel cylinders 51 to 54 and the reservoirs 23 and 24 to the hydraulic pressure generator 2.

With the above configuration, by turning on and off the solenoids of the solenoid valves 31 to 38, the wheel cylinder 5
The brake fluid pressures 1 to 54 can be increased, maintained, and reduced. That is, the solenoid valves 31 to 38
When the solenoid is off, the brake fluid pressure is supplied to the wheel cylinders 51 to 54 from the fluid pressure generator 2 and the pumps 21 and 22 to increase the pressure. When the solenoid is on, the wheel cylinders 51 to 54 24 and the pressure is reduced. The solenoids of the solenoid valves 31, 33, 35 and 37 are turned on, and the solenoid valves 32, 34, 36 and 38 are turned on.
When the solenoid is turned off, the brake fluid pressure is maintained. Therefore, by adjusting the energizing time to the solenoid, it is possible to perform a pulse pressure increase that combines pressure increase and hold, or a pulse pressure decrease that combines pressure decrease and hold, and gradually increase or decrease the brake fluid pressure. Can be controlled as described above.

An electronic control unit (braking force control means) 1
0 is connected to the solenoid valves 31 to 38 and controls each of the solenoid valves and the motor 20. Each wheel has a wheel speed sensor (wheel speed detecting means) 41 to 4 for detecting a wheel speed.
4 is provided to the electronic control unit 10 together with the brake switch 45. The wheel speed sensor is composed of a toothed rotor that rotates with the rotation of each wheel, and an electromagnetic induction type sensor that is provided opposite to the tooth portion of the rotor, and converts a frequency according to the rotation speed of each wheel into a voltage. And output it.

The electronic control unit 10, as shown in FIG.
CPU 14 and ROM 1 mutually connected via a bus
5, a microcomputer comprising a RAM 16, a timer 17, an input port 12 and an output port 13. The output signals of the wheel speed sensors 41 to 44, the brake switch 45, and the fluid pressure sensors (fluid pressure detecting means) 46 and 47 are inputted to the CPU 14 from the input port 12 through the amplifier circuits 18a to 18g. It has become. Further, a control signal is output from the output port 13 to the electric motor 20 via the drive circuit 19a, and a control signal is output to the solenoid valves 31 to 38 via the drive circuits 19b to 19i. In the microcomputer 11, the ROM 15 stores an anti-skid control program, the CPU 14 executes the program when an ignition switch (not shown) is turned on, and the RAM 16 temporarily stores variable data necessary for executing the program. Remember.

In the present embodiment configured as described above, when an ignition switch (not shown) is turned on, a program is executed, and the processing shown in FIGS. 3 and 4 is performed.

FIGS. 3, 4 and 9 show an embodiment of the present invention. First, in step 101, the microcomputer 11 is initialized, and various calculation values, the estimated vehicle speed Vso serving as a reference vehicle speed for control, the wheel speed Vw, the wheel acceleration DVw, and the like are cleared. Next, in step 102, the wheel speed Vw of each wheel is calculated based on the output signals of the wheel speed sensors 41 to 44, and in step 103, the wheel acceleration DVw is calculated from the calculated value by the wheel speed calculation. In the next step 104, it is determined whether or not the anti-skid control (ABS control) is being performed. If the control is being performed, the process jumps to step 106. If the control is not being performed (before control), step 105 is performed. In step 105, the ABS control start condition is determined, and if the ABS control start condition is satisfied, step 106 is executed, and AB
If the S control start condition is not satisfied, the process jumps to step 115. Step 10 when the control start condition is satisfied
6, the road surface is determined, and the road surface condition during traveling is obtained by calculation. Next, in step 107, one of the control modes of pressure reduction, pressure increase, and holding is selected. Next, it is determined in step 108 whether or not the control mode selected in step 107 is the pressure reduction mode. If the selected control mode is the pressure reduction mode, pressure reduction output is performed in step 109. If the control mode is other than the pressure reduction mode, it is determined in step 110 whether or not the mode is the pulse pressure increase mode.
It is determined in step 11 whether or not the pedal effort has been relaxed from the result of the pedal effort relaxation determination described later. If the pedal effort has been relaxed, a pulse pressure increase output corresponding to the pedal effort relaxation is performed in step 112, and if the pedal effort has not been relaxed, Performs a normal pulse pressure increase output in step 113. As shown in FIG. 13, the pulse pressure increase output corresponding to the depression of the pedaling force increases the pressure increase time of the solenoid valve as shown by the broken line, and consequently increases the pressure increase gradient of the wheel cylinder hydraulic pressure. Next, it is determined in step 110 whether or not the mode is the pulse pressure increasing mode. If the mode is not the pulse pressure increasing mode, the holding output is performed in step 114. Next, at step 115, a determination is made as to whether the pedaling force is to be loosened. The details of step 115 are a routine shown in FIG.

In FIG. 4, first, at step 201, the generated hydraulic pressure Pt of the master cylinder (hydraulic pressure generating device) 2 detected by the hydraulic pressure sensors (hydraulic pressure detecting means) 46, 47
Is read. In step 202, it is determined whether or not the ABS control is being performed. If the control is being performed, step 203 is performed. If the control is not being performed (before control), the process jumps to step 209. In steps 203 to 205, the maximum value of the generated hydraulic pressure Pt is updated. That is, in step 203, it is determined whether or not the generated hydraulic pressure Pt at a certain time is greater than the value _{Pmax (n-1)} that was previously set to the maximum value.
t is not yet greater than the predetermined value P ₁ is determined. That is, the peak value P in which Pt is larger than _{Pmax (n-1)}
If t ₁ is reached, the value is set to a new maximum value P _{max (n)} in step 205. Next, in step 206,
New maximum value P _{max (n)} and new maximum value P
_max difference _{ΔP = P max (n) -Pt} 2 and the value Pt ₂ of Pt _{after (n)} is a predetermined time has elapsed from the time that occurred is determined whether a predetermined value _{K 1} or more, [Delta] P is a predetermined value If K ₁ or more, the process proceeds to step 207. Step 207
Then, it is determined whether or not all four wheels are in the pulse pressure increasing mode. If all four wheels are in the pulse pressure increasing mode, step 20 is executed.
Proceeding to 8, it is determined that the pedaling force has been released, and the process returns to the main routine. That is, steps 203 to 20
In No. 7, when the generated hydraulic pressure Pt continues to decrease after reaching the maximum value, and when the decrease value is equal to or more than a predetermined value and all four wheels are in the pulse pressure increasing mode, it is determined that the pedaling force is released. It is. If it is determined in step 207 that at least one of the four wheels is in the depressurizing mode or the holding mode, the process proceeds to step 209, where it is determined that the pedaling force is not in a loosened state, and the process returns to the main routine.

Returning to FIG. 3, it is determined in step 116 whether or not the four wheels have completed the same processing. If the processing has not been completed for all four wheels, the flow returns to step 102 to repeat the same processing. . When the processing for all four wheels is completed, the estimated vehicle speed Vso as a reference for the ABS control is calculated from the output signals of the wheel speed sensors 41 to 44 in step 117, and the process returns to step 102 to repeat the process. .

Next, the invention according to claim 2 will be described with reference to FIGS. 3, 5, and 10. FIG. In FIG.
First, at step 301, a hydraulic pressure sensor (hydraulic pressure detecting means) 4
The generated hydraulic pressure of the master cylinder (hydraulic pressure generating device) 2 detected by 6, 47 is read. In step 302, it is determined whether or not the ABS control is being performed. If the control is being performed, step 303 is executed. If the control is not being performed (before control), the process jumps to step 308. In step 303, generating pressure Pt ₁ at time _{t 1} it is determined whether or not and if negative time derivative of Pt at a predetermined value _{P 1} or more, and the time differential value of Pt Pt ₁ is at a predetermined value _{P 1} or more Is negative, the process proceeds to step 304. In step 304, generating pressure Pt ₂ at time _{t 2} has elapsed from the time _{t 1} the predetermined time is determined whether or not and if negative time derivative value of Pt is equal to or less than a predetermined value _{P 2,} Pt ₂ is a predetermined value _{P 2} If it is below and the time differential value of Pt is negative, the process proceeds to step 305. In step 305, it is determined whether or not all the four wheels are in the pulse pressure increasing mode.
Proceeding to 6, it is determined that the pedaling force is in a loosened state. That is,
In steps 303 to 305, after the generated hydraulic pressure Pt becomes equal to or more than the first predetermined value, the pressure continues to decrease.
Becomes smaller than the second predetermined value, which is smaller than the predetermined value, and if the four wheels are in the pulse pressure increasing mode, it is determined that the pedaling force is in the loosened state. In this embodiment, when it is determined that the pedaling force is loosened, the ABS control is stopped and the brake is returned to the normal brake state. Done. For this reason,
When the process returns to the main routine (FIG. 3) after the end of step 307, the process jumps from step 103 to step 115, and the ABS control is stopped. If it is determined in step 305 that at least one of the four wheels is in the depressurizing mode or the holding mode, the process proceeds to step 308, in which it is determined that the pedaling force is not in a loosened state, and the process returns to the main routine.

Steps 303 to 304 in FIG. 5 may be replaced with steps 203 to 206 in FIG.
May be replaced by

Next, the invention according to claim 3 will be described with reference to FIGS. 3, 6, and 11. FIG. In FIG.
First, at step 401, a hydraulic pressure sensor (hydraulic pressure detecting means) 4
The generated hydraulic pressure of the master cylinder (hydraulic pressure generating device) 2 detected by 6, 47 is read. In step 402, it is determined whether or not the ABS control is being performed. If the control is being performed, step 403 is executed. If the control is not being performed (before control), the process jumps to step 408. In step 403, the difference between the hydraulic pressure generated Pt ₂ in generating hydraulic pressure Pt ₁ and the time time _{t 2} from _{t 1} the predetermined time has elapsed at time _{t 1,} a value obtained by dividing a predetermined value at the time difference _t 1 -t ₂ K2 (negative value)
It is determined whether or not: If the value is equal to or smaller than the predetermined value K2, the process proceeds to step 404. If the value is larger than the predetermined value K2, the process jumps to step 408. In step 404, it is determined whether or not all four wheels are in the pulse pressure increasing mode. If all four wheels are in the pulse pressure increasing mode, the process proceeds to step 405, and it is determined that the pedaling force is in a state of loosening. That is, step 403
In steps 404 to 404, when the rate of decrease of the generated hydraulic pressure Pt with respect to time is equal to or greater than a predetermined value and all four wheels are in the pulse pressure increasing mode, it is determined that the pedaling force is in a loosened state.
When it is determined that the pedaling force is loosened, the process proceeds to step 406. In this embodiment, when it is determined that the pedaling force is loosened, the ABS control is stopped for only the front wheels and the brake is returned to the normal brake. For this reason, after step 405, it is determined whether or not the front system is being calculated in step 406.
If the front system is being calculated, it is determined in a step 407 that “before ABS control”, and preparations are made to suspend control of the front system. When the process returns to the main routine (FIG. 3) after the end of step 407, the process jumps from step 103 to step 115 during the calculation of the front system, and the ABS control of the front system is stopped. If it is determined in step 406 that the front system is not calculating, the process directly returns to the main routine.

Step 403 in FIG. 6 may be replaced with steps 203 to 206 in FIG. 4 and may be replaced with steps 303 to 304 in FIG.

Next, an embodiment of the invention according to claim 4 is as follows.
Although shown in FIG. 4 and FIG.

Next, a fifth embodiment of the invention will be described with reference to FIGS. Although FIG. 5 has already been described, in the invention according to claim 5, a flowchart in which step 307 is omitted may be used.

Next, a sixth embodiment of the present invention will be described with reference to FIGS. Although FIG. 6 has already been described, in the invention according to claim 6, a flowchart in which steps 406 and 407 are omitted may be used.

Next, the invention according to claim 7 will be described with reference to FIGS. 7, 8 and 12. , FIG. 7, FIG. 8 and FIG. 12 show that when the pumping brake is applied,
9 is a control flow and a time chart illustrating an example of a re-stepping determination for determining a re-stepping performed immediately after the brake pedal force is released. Note that in FIG.
Steps 510 to 510 are exactly the same control flows as steps 101 to 110 of the embodiment shown in FIG.

First, it is determined in step 510 whether or not the mode is the pulse pressure increasing mode. If the mode is the pulse pressure increasing mode, it is determined in step 511 whether or not the vehicle is in the re-stepping state based on the result of the later-described step determination. If it is in the re-stepping state, a pulse pressure increase output corresponding to the re-stepping is performed in step 512, and if not, a normal pulse pressure increase output is performed in step 513. Note that the re-stepping-in response pulse pressure increase output in step 512 is a mode in which the holding time is set to zero and the pressure is rapidly increased. Next, it is determined in step 510 whether or not the mode is the pulse pressure increasing mode. If the mode is not the pulse pressure increasing mode, the holding output is performed in step 514. Next, after a determination is made in step 515 that the pedaling force is loosened, step 516 is performed.
Is used to make a re-stepping determination. The details of the re-stepping determination are shown in FIG.
Is shown in

In FIG. 8, first, it is determined in step 601 whether or not the pedaling force has been relaxed. If the pedaling force has been relaxed, the process proceeds to step 602. If the pedaling force has not been relaxed, the process jumps to step 602 and repeats Outputs when not in the depressed state. Next, in step 602, and time differential value of Pt at a predetermined value P ₃ or higher generated pressure Pt ₃ at time t ₃ after a predetermined time from the time it is determined that the pedal force has been loosened is positive or not If it is determined that Pt ₃ is equal to or more than the predetermined value P ₃ and the time derivative of Pt is positive, the process proceeds to step 603. In step 603, it is determined whether or not all four wheels are in the pulse pressure increasing mode. If all four wheels are in the pulse pressure increasing mode, the flow proceeds to step 604 to output that the vehicle is in the stepping-on state again, and then returns to the main routine. .

Returning to FIG. 7, at step 517, it is determined whether or not the same process has been completed for all four wheels. If all four wheels have not been completed, the process returns to step 502 to repeat the same process. . When the processing for all four wheels is completed, the estimated vehicle speed Vso as a reference for the ABS control is calculated from the output signals of the wheel speed sensors 41 to 44 in step 518, and the process returns to step 502 to repeat the process. .

Next, in the invention according to claims 8 to 10, in the invention according to claim 7, the stepping force loosening judgment performed prior to the re-stepping judgment is made according to the method according to claims 4 to 6. The description will be omitted because it is performed by means.

In each of the above embodiments, the determination of the stepping force loosening and the stepping-in step are performed based on the hydraulic pressure generated by the master cylinder. However, in addition to the hydraulic pressure generated by the master cylinder, a G sensor signal, a vehicle deceleration signal The above determination may be made based on the above.

[0046]

According to the present invention, when the pumping brake operation is performed during the anti-skid control, the state of the pumping brake or a precursor thereof is detected from the generated hydraulic pressure of the master cylinder (hydraulic pressure generating device). By increasing the pressure increase time of the pulse pressure increase or the like, the shutoff time between the master cylinder and the wheel cylinder can be shortened, and a feeling of plate brake can be prevented.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a brake fluid pressure control device according to the present invention.

FIG. 2 is a block diagram showing a configuration of the electronic control device of FIG.

FIG. 3 is a flowchart showing an outline of anti-skid control in the embodiment of the invention according to claim 1;

FIG. 4 is a flowchart showing an embodiment of the invention according to claim 4;

FIG. 5 is a flowchart showing an embodiment of the invention according to claims 2 and 5;

FIG. 6 is a flowchart showing an embodiment of the invention according to claims 3 and 6;

FIG. 7 is a flowchart showing an outline of anti-skid control in the embodiment of the invention according to claim 7;

FIG. 8 is a flowchart showing details of a re-stepping determination in the embodiment of the invention according to claim 7;

FIG. 9 is a time chart showing details of the determination of the depression of the pedal effort in the embodiment of the invention according to claim 4;

FIG. 10 is a time chart showing details of the determination of the depression of the pedal effort in the embodiment of the invention according to claim 5;

FIG. 11 is a time chart showing details of the determination of the depression of the pedaling force in the embodiment of the invention according to claim 6;

FIG. 12 is a time chart showing details of re-stepping determination in the embodiment of the invention according to claim 7;

FIG. 13 is a time chart showing the anti-skid control based on the determination of the depression of the pedaling force or the determination of the stepping on again.

[Explanation of symbols]

 2 Hydraulic pressure generator 2a Master cylinder (hydraulic pressure generator) 2b Booster (hydraulic pressure generator) 3 Brake pedal (hydraulic pressure generator) 10 Electronic controller (braking force control means) 30 Actuator (hydraulic pressure controller) 31 -38 Solenoid valve (fluid pressure control device) 41-44 Wheel speed sensor (wheel speed detecting means) 46, 47 Hydraulic pressure sensor (fluid pressure detecting means) 51-54 Wheel cylinder

Claims (10)

[Claims] 1. A wheel cylinder mounted on each wheel of a vehicle to apply a braking force to the wheel, a hydraulic pressure generator for supplying a brake hydraulic pressure to the wheel cylinder, and connected to the hydraulic pressure generator for operation A brake pedal for transmitting an operator's braking operation to the hydraulic pressure generating device, a hydraulic pressure detecting means for detecting a generated hydraulic pressure of the hydraulic pressure generating device, and a brake pedal disposed between the hydraulic pressure generating device and the wheel cylinder. A hydraulic pressure control device for controlling a brake hydraulic pressure of the wheel cylinder, a wheel speed detecting means for detecting a wheel speed of each wheel, and a wheel speed calculating means for calculating a wheel speed from an output signal of the wheel speed detecting means. A wheel acceleration calculating means for calculating the wheel acceleration of each wheel from the wheel speed, an estimated vehicle speed calculating means for calculating the vehicle speed based on the wheel speed, and a wheel speed and a wheel acceleration. A braking force control unit that controls the braking force by driving the hydraulic pressure control device in accordance with the estimated vehicle speed, wherein the braking force control unit includes a hydraulic pressure applied to the wheel cylinder. Control mode setting means for setting a pressure reducing mode for reducing pressure, a pulse pressure increasing mode comprising a combination of pressure increasing and holding, and a holding mode for holding hydraulic pressure applied to the wheel cylinder, and the braking force controlling means Determining whether or not the brake pedal force applied to the brake pedal has been reduced based on the output signal of the hydraulic pressure detecting means when the brake pressure is being controlled by driving the hydraulic pressure control device. Means for increasing the pressure increasing time of the pulse pressure increase when the stepping force loosening determining means determines that the stepping force is loosened, as compared with the case where the brake stepping force is not loosened. Brake fluid pressure control device, characterized and. 2. A wheel cylinder mounted on each wheel of a vehicle to apply a braking force to the wheel, a hydraulic pressure generator for supplying brake hydraulic pressure to the wheel cylinder, and connected to the hydraulic pressure generator for operation. A brake pedal for transmitting an operator's braking operation to the hydraulic pressure generating device, a hydraulic pressure detecting means for detecting a generated hydraulic pressure of the hydraulic pressure generating device, and a brake pedal disposed between the hydraulic pressure generating device and the wheel cylinder. A hydraulic pressure control device for controlling a brake hydraulic pressure of the wheel cylinder, a wheel speed detecting means for detecting a wheel speed of each wheel, and a wheel speed calculating means for calculating a wheel speed from an output signal of the wheel speed detecting means. A wheel acceleration calculating means for calculating the wheel acceleration of each wheel from the wheel speed, an estimated vehicle speed calculating means for calculating the vehicle speed based on the wheel speed, and a wheel speed and a wheel acceleration. A braking force control unit that controls the braking force by driving the hydraulic pressure control device in accordance with the estimated vehicle speed, wherein the braking force control unit includes a hydraulic pressure applied to the wheel cylinder. Control mode setting means for setting a pressure reducing mode for reducing pressure, a pulse pressure increasing mode comprising a combination of pressure increasing and holding, and a holding mode for holding hydraulic pressure applied to the wheel cylinder, and the braking force controlling means Determining whether or not the brake pedal force applied to the brake pedal has been reduced based on the output signal of the hydraulic pressure detecting means when the brake pressure is being controlled by driving the hydraulic pressure control device. Means for controlling the braking force, wherein the braking force control means immediately stops controlling the braking force when the pedaling force loosening determining means determines that the pedaling force is loosened. Fluid pressure control device. 3. A wheel cylinder mounted on each wheel of a vehicle for applying a braking force to the wheel, a hydraulic pressure generator for supplying brake hydraulic pressure to the wheel cylinder, and connected to the hydraulic pressure generator for operation. A brake pedal for transmitting an operator's braking operation to the hydraulic pressure generating device, a hydraulic pressure detecting means for detecting a generated hydraulic pressure of the hydraulic pressure generating device, and a brake pedal disposed between the hydraulic pressure generating device and the wheel cylinder. A hydraulic pressure control device for controlling a brake hydraulic pressure of the wheel cylinder, a wheel speed detecting means for detecting a wheel speed of each wheel, and a wheel speed calculating means for calculating a wheel speed from an output signal of the wheel speed detecting means. A wheel acceleration calculating means for calculating the wheel acceleration of each wheel from the wheel speed, an estimated vehicle speed calculating means for calculating the vehicle speed based on the wheel speed, and a wheel speed and a wheel acceleration. A braking force control unit that controls the braking force by driving the hydraulic pressure control device in accordance with the estimated vehicle speed, wherein the braking force control unit includes a hydraulic pressure applied to the wheel cylinder. Control mode setting means for setting a pressure reducing mode for reducing pressure, a pulse pressure increasing mode comprising a combination of pressure increasing and holding, and a holding mode for holding hydraulic pressure applied to the wheel cylinder, and the braking force controlling means Determining whether or not the brake pedal force applied to the brake pedal has been reduced based on the output signal of the hydraulic pressure detecting means when the brake pressure is being controlled by driving the hydraulic pressure control device. The braking force control means immediately stops controlling the braking force of the front wheel when the pedaling force loosening determining means determines that the pedaling force is loosened. Rake fluid pressure control device. 4. The brake control device according to claim 1, wherein the stepping force loosening determining unit determines that a maximum value of the brake fluid pressure detected by the fluid pressure detecting unit is equal to or greater than a first predetermined value. When the brake fluid pressure after a lapse of a predetermined time from the time when the maximum value of the brake fluid pressure is generated becomes smaller than the maximum value of the brake fluid pressure by a second predetermined value, it is determined that the pedaling force is reduced. Brake fluid pressure control device. 5. The brake fluid pressure control device according to claim 1, wherein said pedaling force loosening determining means determines that the brake fluid pressure detected by said fluid pressure detecting means is equal to or higher than a first predetermined value and said brake fluid pressure When the brake fluid pressure after a lapse of a predetermined time from a time when the brake fluid pressure becomes equal to or more than a first predetermined value becomes equal to or less than a second predetermined value that is smaller than the first predetermined value, it is determined that the pedaling force is reduced. Brake fluid pressure control device. 6. The brake control device according to claim 1, wherein the pedaling force loosening determining unit determines a brake fluid pressure detected by the hydraulic pressure detecting unit at a first predetermined time and a first predetermined time. Determining that the pedal effort has been relaxed when a value obtained by dividing a difference from a brake fluid pressure detected at a second predetermined time after a predetermined time has elapsed by a predetermined time is equal to or less than a predetermined value. Pressure control device. 7. A wheel cylinder mounted on each wheel of a vehicle to apply a braking force to the wheel, a hydraulic pressure generator for supplying brake hydraulic pressure to the wheel cylinder, and connected to the hydraulic pressure generator for operation A brake pedal for transmitting an operator's braking operation to the hydraulic pressure generating device, a hydraulic pressure detecting means for detecting a generated hydraulic pressure of the hydraulic pressure generating device, and a brake pedal disposed between the hydraulic pressure generating device and the wheel cylinder. A hydraulic pressure control device for controlling a brake hydraulic pressure of the wheel cylinder, a wheel speed detecting means for detecting a wheel speed of each wheel, and a wheel speed calculating means for calculating a wheel speed from an output signal of the wheel speed detecting means. A wheel acceleration calculating means for calculating the wheel acceleration of each wheel from the wheel speed, an estimated vehicle speed calculating means for calculating the vehicle speed based on the wheel speed, and a wheel speed and a wheel acceleration. A braking force control unit that controls the braking force by driving the hydraulic pressure control device in accordance with the estimated vehicle speed, wherein the braking force control unit includes a hydraulic pressure applied to the wheel cylinder. Control mode setting means for setting a pressure reducing mode for reducing pressure, a pulse pressure increasing mode comprising a combination of pressure increasing and holding, and a holding mode for holding hydraulic pressure applied to the wheel cylinder, and the braking force controlling means Determining whether or not the brake pedal force applied to the brake pedal has been reduced based on the output signal of the hydraulic pressure detecting means when the brake pressure is being controlled by driving the hydraulic pressure control device. Means, and the brake depression force applied to the brake pedal is reduced based on the output signal of the hydraulic pressure detection means, and the brake depression force is applied again after a predetermined time has elapsed. Whether a re-depression determination means for determining, when said re-depression determining unit determines that re-depression, the brake fluid pressure control apparatus characterized by a zero hold time in the pulse pressure increase. 8. The brake control device according to claim 7, wherein said stepping force loosening determining means determines that the maximum value of the brake hydraulic pressure detected by said hydraulic pressure detecting means is equal to or greater than a first predetermined value and that the maximum value of the brake hydraulic pressure is generated. A brake fluid pressure control device characterized in that it is determined that the pedaling force has been relaxed when the brake fluid pressure after a lapse of a predetermined time from the time when the brake fluid pressure becomes smaller by a second predetermined value than the maximum value of the brake fluid pressure. 9. The brake control device according to claim 7, wherein the stepping force loosening determining means determines that the brake fluid pressure detected by the fluid pressure detecting means is equal to a first fluid pressure.
When the brake fluid pressure after a lapse of a predetermined time from the time when the brake fluid pressure has become equal to or more than the first predetermined value becomes equal to or less than a second predetermined value smaller than the first predetermined value. A brake fluid pressure control device that determines that the pedaling force has been relaxed. 10. The brake control device according to claim 7, wherein said stepping force loosening determining means includes a brake fluid pressure detected by said fluid pressure detecting means at a first predetermined time and a second brake fluid pressure after a lapse of a predetermined time from said first predetermined time. A brake fluid pressure control device that determines that the pedaling force has been relaxed when a value obtained by dividing a difference from a brake fluid pressure detected at a predetermined time by a predetermined time becomes equal to or less than a predetermined value.