JP2000062600A - Brake fluid pressure control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake fluid pressure control device to maintain an electric control type hydraulic brake system even when a trouble, such as a failure in operation, occurs to a pressure sensor to detect the fluid pressure of a fluid pressure source or a pressure switch. SOLUTION: From the wheel cylinder pressure of each wheel, calculated by fluid pressure sensors 118, 120, 122, and 124 and the voltage of a motor 78 to drive a pump 80, an accumulator pressure estimated value is calculated. By comparing the estimated value with an accumulator pressure measuring value, abnormality of a fluid pressure sensor 116 to detect the fluid pressure of an accumulator 70 is detected. Control to drive the pump 80 is changed to the control effected by an accumulator pressure estimated value instead of control effected by an accumulator pressure measuring value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake fluid pressure control device.

[0002]

2. Description of the Related Art As a conventional brake fluid pressure control device,
For example, as shown in Japanese Patent Application Laid-Open No. 06-191393,
There is an electrically controlled hydraulic brake in which normal braking force is performed based on the hydraulic pressure of a hydraulic pressure source provided separately from the master cylinder. In this conventional brake hydraulic pressure control device, the hydraulic pressure control device is a proportional electromagnetic hydraulic pressure control device that controls the hydraulic pressure of the hydraulic pressure source to a height proportional to the current supplied to the coil, and brake operation is also performed. An operation amount detection means for detecting the operation amount of the member is provided. Further, the control means sets the target wheel cylinder pressure based on the detection result of the operation amount detection means, and controls the current supplied to the coil of the proportional electromagnetic hydraulic pressure control device such that the hydraulic pressure of the hydraulic pressure source is the target wheel cylinder pressure. The wheel cylinder can obtain a hydraulic pressure having a height corresponding to the operation amount of the brake operation member, for example, a hydraulic pressure proportional to the operation amount or a vehicle body deceleration proportional to the operation force. The hydraulic pressure is supplied to suppress wheel rotation. In addition, if an abnormality occurs in the electrically controlled hydraulic brake and the hydraulic pressure from the hydraulic pressure source cannot be supplied to the wheel cylinder, switch to the mechanical brake that directly supplies the hydraulic pressure from the master cylinder to the wheel cylinder. It has become.

[0003]

However, in such a conventional brake hydraulic pressure control device, when an abnormality such as a failure occurs in the pressure sensor or the pressure switch for detecting the hydraulic pressure of the hydraulic pressure source. Despite the fact that there is no abnormality in the hydraulic pressure source, the electrically controlled hydraulic brake cannot be maintained and the hydraulic pressure from the master cylinder is switched to the mechanical brake that directly supplies it to the wheel cylinder. There was a point. The present invention has been made in view of such conventional problems. Even when an abnormality such as a failure occurs in the pressure sensor or the pressure switch that detects the hydraulic pressure of the hydraulic pressure source, the electrically controlled hydraulic pressure is used. By maintaining the braking system, the aim is to solve the problems of the prior art.

[0004]

In order to solve the above-mentioned problems, in the invention according to claim 1, a brake operating member, an operation amount detecting means for detecting the operation amount of the brake operating member, and a pump are provided. A hydraulic pressure source that includes the hydraulic pressure source, a hydraulic pressure source hydraulic pressure detection unit that detects the hydraulic pressure of the hydraulic pressure source, and a pump drive control unit that controls the drive of the pump based on the detection amount of the hydraulic pressure source hydraulic pressure detection unit. A plurality of wheel cylinders that respectively suppress the rotation of a plurality of wheels, a plurality of wheel cylinder pressure detection means that detect the hydraulic pressure of each of the plurality of wheel cylinders, the hydraulic pressure source, and the plurality of wheel cylinders. A plurality of liquid passages respectively connecting to each other, a plurality of liquid pressure control devices provided in each of the liquid passages for controlling the hydraulic pressure of the wheel cylinder, and the liquid based on the detected amount of the operation amount detecting means. In a brake fluid pressure control device including a fluid pressure control device control means for controlling the control device, a fluid pressure of the fluid pressure source is estimated from a detection amount of the wheel cylinder pressure detection means and a command value of the pump drive control means. A hydraulic pressure source hydraulic pressure estimating means and a wheel cylinder pressure estimating means for estimating the hydraulic pressure of the wheel cylinder from a command value of the hydraulic pressure control device controlling means, and a detection amount of the hydraulic pressure source hydraulic pressure detecting means. And the estimated amount of the hydraulic pressure source hydraulic pressure estimation means exceeds a first threshold value, or the estimated amount of the hydraulic pressure source hydraulic pressure estimation means and the detected amount of the hydraulic pressure source hydraulic pressure detection means. Is greater than a first threshold value and the difference between the estimated amount of the wheel cylinder pressure estimation means and the detected amount of the wheel cylinder pressure detection means does not exceed a second threshold value, the hydraulic pressure source hydraulic pressure estimation Drive the pump based on the estimated amount of means It is characterized by changing the pump drive control means to. In the invention according to claim 2, the brake operating member, the operation amount detecting means for detecting the operation amount of the brake operating member, the hydraulic pressure source including the pump, and the hydraulic pressure of the hydraulic pressure source depend on the hydraulic pressure source 2 The fluid pressure source fluid pressure switch that switches to the normal state and the pump is not driven when the fluid pressure source fluid pressure switch is in the first state, and the pump is driven when it is in the second state. Pump drive control means for controlling the drive of the pump, a plurality of wheel cylinders for respectively suppressing the rotation of a plurality of wheels, and a plurality of wheel cylinder pressure detection means for detecting the hydraulic pressure of each of the plurality of wheel cylinders A plurality of fluid passages respectively connecting the fluid pressure source and the plurality of wheel cylinders, and a plurality of fluid pressure control devices provided in each of the fluid passages to suppress the fluid pressure of the wheel cylinders, In a brake fluid pressure control device including a fluid pressure control device control means for controlling the fluid pressure control device based on the detection amount of the operation amount detection means, a detection amount of the wheel cylinder pressure detection means and the pump drive control means. Hydraulic pressure source hydraulic pressure estimating means for estimating the hydraulic pressure of the hydraulic pressure source and the state of the hydraulic pressure source hydraulic pressure switch from the command value of, and the hydraulic pressure of the wheel cylinder from the command value of the hydraulic pressure control device control means. Wheel cylinder pressure estimating means for estimating a pressure, wherein the switch estimation state of the hydraulic pressure source hydraulic pressure estimating means and the state of the hydraulic pressure source hydraulic pressure switch differ for a time period exceeding a third threshold value, and When the state of the pressure source hydraulic pressure switch is the first state, or when the switch estimated state of the hydraulic pressure source hydraulic pressure estimating means and the state of the hydraulic pressure source hydraulic pressure switch are different for a time exceeding the third threshold value, And the liquid pressure When the state of the hydraulic pressure switch is the second state, and the difference between the estimated amount of the wheel cylinder pressure estimating means and the detected amount of the wheel cylinder pressure detecting means does not exceed the second threshold value, the hydraulic pressure The pump drive control means is changed so as to drive the pump based on the estimated amount of the source hydraulic pressure estimation means. According to a third aspect of the present invention, in the brake hydraulic pressure control device according to the first aspect, the absolute value of the difference between the detected amount of the hydraulic pressure source hydraulic pressure detecting means and the estimated amount of the hydraulic pressure source hydraulic pressure estimating means. Is less than or equal to a first threshold value, the detected amount of the hydraulic pressure source hydraulic pressure detection means is greater than or equal to a fourth threshold value, and the pump is not driven, the estimated amount of the hydraulic pressure source hydraulic pressure estimation means Is set to the detection amount of the hydraulic pressure source hydraulic pressure detection means. According to a fourth aspect of the present invention, in the brake hydraulic pressure control device according to the second aspect, the switch estimated state of the hydraulic pressure source hydraulic pressure estimating means and the hydraulic pressure source hydraulic pressure switch are equal, and the hydraulic pressure is the same. When the estimated amount of the pressure source hydraulic pressure estimation unit is equal to or larger than a fourth threshold and the pump is not driven, the estimated amount of the hydraulic pressure source hydraulic pressure estimation unit is set to the fourth amount.
It is characterized by substituting the threshold value of.

[0005]

According to the first aspect of the present invention, the estimated amount of the hydraulic pressure of the hydraulic pressure source is obtained by the hydraulic pressure source hydraulic pressure estimating means from the detected amount of the wheel cylinder pressure detecting means and the command value of the pump drive control means. By comparing with the detection amount of the hydraulic pressure source hydraulic pressure detection means, it is possible to detect the abnormality of the hydraulic pressure source hydraulic pressure detection means, and when the abnormality of the hydraulic pressure source hydraulic pressure detection means is detected,
The electric drive type hydraulic brake is maintained by changing the pump drive control means from the control based on the detected amount of the hydraulic pressure source hydraulic pressure detection means to the control based on the estimated amount of the hydraulic pressure source hydraulic pressure estimation means. According to the second aspect of the invention, the estimated amount of the hydraulic pressure of the hydraulic pressure source and the hydraulic pressure source hydraulic pressure are calculated by the hydraulic pressure source hydraulic pressure estimation means from the detected amount of the wheel cylinder pressure detection means and the command value of the pump drive control means. It is possible to detect an abnormality in the hydraulic pressure source hydraulic switch by obtaining the estimated switch state and comparing it with the detected state of the hydraulic pressure source hydraulic switch. Maintains the electrically controlled hydraulic brake by changing the pump drive control means from the control based on the detected state of the hydraulic pressure source hydraulic pressure switch to the control based on the estimated amount of the hydraulic pressure source hydraulic pressure estimation means. . According to the invention of claim 3, in addition to the operation of the invention of claim 1, in the state where there is no abnormality in the fluid pressure source fluid pressure detection means and the fluid is most accumulated in the fluid pressure source by the pump, Since the estimated amount of the pressure source hydraulic pressure estimation means is reset to the detected amount of the hydraulic pressure source hydraulic pressure detection means, the error in the estimated amount of the hydraulic pressure source hydraulic pressure estimation means is reduced. According to the invention described in claim 4, in addition to the operation of the invention described in claim 2, the hydraulic pressure source hydraulic pressure switch is normal, and the hydraulic pressure is stored in the hydraulic pressure source most by the pump. Since the estimated amount of the source hydraulic pressure estimating means is reset to the predetermined threshold value, the error of the estimated amount of the hydraulic source hydraulic pressure estimating means is reduced.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 are diagrams showing a first embodiment of the present invention. First, the configuration will be described with reference to FIG.
Reference numeral 10 is a brake pedal 10 as a brake operating member. The brake pedal 10 is connected to the master cylinder 12, and a hydraulic pressure (referred to as a master cylinder pressure) corresponding to the pedaling force of the brake pedal 10 is generated in each of the two pressurizing chambers of the master cylinder 12. One pressurizing chamber of the master cylinder 12 has a front wheel cylinder 26 of a brake provided on each of the left and right front wheels 22, 24 by means of the liquid passages 14, 16 and the branch passages 18, 20.
28, and the other pressurizing chamber has a liquid passage 30,
The left and right rear wheels 38, 4 by the 32 and the branch passages 34, 36
0 are connected to the rear wheel cylinders 42 and 44 of the brakes respectively installed in the vehicle. 46 is the rear wheel 38, 40
3 is a proportioning valve provided in a liquid passage 32 for use in the.

Electromagnetic directional control valves 50, 52, 54 and 56 are provided in the branch passages 18, 20, 34 and 36, respectively, and proportional electromagnetic hydraulic pressure control valves 58, 60, 62 and 64 are connected thereto. . Electromagnetic directional control valve 50, 52, 54, 5
The solenoid 6 is always demagnetized and in the original position shown in FIG. 1, and connects the wheel cylinders 26, 28, 42 and 44 to the proportional electrohydraulic pressure control valves 58, 60, 62 and 64. When it is excited, it is switched to the opposite position, and the wheel cylinders 26, 28, 42, 44 are communicated with the master cylinder 12.

Proportional electromagnetic hydraulic control valves 58, 60, 62, 6
4 are respectively connected to an accumulator 70 as a hydraulic pressure source and a reservoir 72 by liquid passages 74 and 76, and a pump 80 driven by a motor 78 when the hydraulic pressure of the accumulator 70 falls below a certain threshold value. By this, the liquid in the reservoir 72 is pumped up until the liquid pressure in the accumulator 70 reaches another threshold value, and the liquid is stored in the accumulator 70 at a certain range of liquid pressure.

Proportional electromagnetic hydraulic control valves 58, 60, 62, 6
Reference numeral 4 controls the hydraulic pressure of the accumulator 70 (referred to as accumulator pressure) by controlling the excitation current of the solenoid to supply the hydraulic pressure to the wheel cylinders 26, 28, 42, 44.
The brake operates based on the hydraulic pressure of the wheel cylinders 26, 28, 42, 44 (referred to as wheel cylinder pressure), and rotation of the wheels is suppressed.

Between the liquid passages 14 and 16 connecting the master cylinder 12 and the front wheel cylinders 26 and 28, and between the liquid passages 30 and 32 connecting the master cylinder 12 and the rear wheel cylinders 42 and 44. Are provided with electromagnetic directional control valves 84 and 86, respectively, and stroke simulators 88 and 90 are connected thereto. The stroke simulators 88 and 90 store the brake fluid discharged from the master cylinder 12 to allow the brake pedal 10 to be depressed, and to apply a reaction force corresponding to the depression stroke to the brake pedal 10. The rotation of the wheels is proportional to the proportional hydraulic pressure control valves 58, 60, 62, 64.
In the state of being controlled based on the wheel cylinder pressure controlled by, the solenoids of the electromagnetic directional control valves 84, 86 are demagnetized, the master cylinder 12 is made to communicate with the stroke simulators 88, 90, and the driver feels as if the wheel cylinders. 26, 28, 42, and 44 are provided to give an operation feeling as if they were connected.

The brake fluid pressure control device is a control device 100.
Controlled by. The control device 100 is a CPU 102,
ROM 104, RAM 106, input unit 108, output unit 1
Includes 10 and bus. Input unit 1 of control device 100
Reference numeral 08 denotes a brake switch 112 for detecting the depression of the brake pedal 10, and a pedal effort detection device 11 as an operation amount detecting means for detecting the depression force of the brake pedal 10.
4, hydraulic pressure sensor 1 for detecting the hydraulic pressure of the accumulator 70
16, hydraulic sensors 118, 120, 122, 124 as wheel cylinder pressure detecting means for detecting wheel cylinder pressures of the wheel cylinders 26, 28, 42, 44,
Wheel speed sensors 126, 128, 130, 13 for detecting the respective rotational speeds of the left and right front wheels 22, 24 and rear wheels 38, 40.
2. A front and rear G sensor 144 and a lateral G sensor 146, which detect decelerations in the front-rear direction and the lateral direction of the vehicle body, respectively, are connected. The input unit 108 includes a circuit that performs appropriate signal processing such as converting a signal supplied from each detection device or sensor into a digital signal when the signal is an analog signal.

The output portion 110 has a proportional electromagnetic hydraulic pressure control valve 5
8, 60, 62, 64 and electromagnetic directional control valves 50, 52,
54, 56, 84 and 86 are connected. Output unit 11
0 is provided with drive circuits corresponding to the proportional electrohydraulic control valves 58, 60, 62, 64 and the electromagnetic directional control valves 50, 52, 54, 56, 84, 86, respectively. It is connected to the circuit. The output unit 110 is further provided with proportional electrohydraulic pressure control valves 58, 60, 62, 64.
There is also provided a D / A converter for converting the command value determined by a digital value into each of the drive circuits and converting the command value into an analog signal and supplying the analog signal. In the ROM 104, a map defining the relationship between the pedaling force of the brake pedal 10 and the target deceleration, a wheel rotation suppression routine, which will be described later, an accumulator pressure detecting means abnormality detection routine, and an accumulator pressure detecting means control routine 1, 2 Is stored.

The braking by the brake fluid pressure control device of the present embodiment is usually performed by proportional electromagnetic fluid pressure control valves 58, 60, 6
The electromagnetic directional control valves 50, 52, 54, 56, 84, 86 are always demagnetized, and the wheel cylinders 26, 28, 42, 44 are controlled by proportional electromagnetic hydraulic pressure control. The master cylinder 12 is communicated with the valves 58, 60, 62 and 64, and the master cylinder 12 has a stroke simulator 8
It is connected to 8, 90. However, an abnormality occurs in the brake fluid pressure control device of the present embodiment, and the fluid pressure from the fluid pressure source is adjusted based on the output fluid pressure of the proportional electromagnetic fluid pressure control valves 58, 60, 62, 64. 28, 42,
44 cannot be supplied to the electromagnetic directional control valve 50,
The solenoids 52, 54, 56, 84, 86 are excited and switched to the position opposite to the original position shown in FIG.
The hydraulic pressure of the wheel cylinders 26, 28, 42, 44 is mechanically controlled based on the hydraulic pressure of the master cylinder 12.

Next, the operation will be described with reference to the flowcharts of FIGS. FIG. 2 is a flowchart of the wheel rotation suppression routine. First, step S1 (hereinafter, S
Abbreviated as 1. The same applies to other steps), and if the brake pedal 10 is not depressed, S1
The result of the determination is NO, and the execution of the routine ends.
If the brake pedal 10 is stepped on, the determination result of S1 is YES and S2 is executed.
After the stepping force of 0 and the deceleration of the vehicle body are read, S3
At, the target deceleration is determined. Next, S4 is executed to set the target wheel cylinder pressure to be supplied to the wheel cylinders 26, 28, 42, 44. Next, in S5, the command value (digital value) for the drive circuit of the proportional electrohydraulic control valves 58, 60, 62, 64 is determined. S
In S6, the command value determined in 5 is converted into an analog signal by the D / A converter and then supplied to the drive circuit, and the proportional electromagnetic hydraulic pressure control valves 58, 60, 6 are accordingly supplied.
2, 64 are driven to drive the wheel cylinders 26, 28, 4
The hydraulic pressure of 2,44 is controlled.

FIG. 3 is a flow chart of a routine for detecting an abnormality of the hydraulic pressure sensor 116, which is the hydraulic pressure detecting means of the accumulator 70. This routine is executed at regular intervals regardless of whether braking is being performed. First, S101 is executed to read the wheel cylinder pressure, which is the hydraulic pressure of the wheel cylinders 26, 28, 42, and 44, and the voltage of the motor 78 that drives the pump 80. Next, in S102, the accumulator pressure estimated value is calculated as follows from the wheel cylinder pressure and the motor voltage. The value of the wheel cylinder pressure of each wheel, the wheel cylinder 26 of each wheel,
The amount of liquid consumed in the wheel cylinders 26, 28, 42, 44 of each wheel is calculated from the characteristics of the amount of liquid-pressure in 28, 42, 44. The wheel cylinder 26 of each wheel,
The liquid consumption amount of the accumulator 70 is calculated by obtaining the sum of the liquid amounts consumed in 28, 42, and 44. On the other hand, the amount of liquid supplied from the pump 80 to the accumulator 70 is calculated from the voltage value of the motor 78 and the characteristics of motor voltage-pump liquid amount. An estimated accumulator pressure value is calculated based on the amount of liquid consumed by the accumulator 70, the amount of liquid supplied from the pump 78 to the accumulator 70, and the amount-fluid pressure characteristic of the accumulator 70. Next, in S103, the accumulator 7
The accumulator pressure measurement value is read by the hydraulic pressure sensor 116 that detects a hydraulic pressure of zero. Next, S104 is executed, and it is determined whether (accumulator pressure measurement value-accumulator pressure estimated value)> X1 (certain threshold value), and if NO, the process proceeds to S105. If YES, the routine is terminated and the accumulator pressure detecting means abnormal time control routine 1 shown in FIG. 4 is executed. If this routine is executed, it is repeated at regular intervals regardless of whether braking is being performed. In S105, it is determined whether (accumulator pressure estimated value-accumulator pressure measured value)> X1 (certain threshold value), and if NO, execution of the routine ends. YE
In the case of S, the execution of the routine is ended, and the accumulator pressure detecting means abnormal time control routine 2 shown in FIG. 5 which will be described later is executed. If this routine is also executed, it is repeated at regular intervals regardless of whether braking is being performed.

Next, the control routine 1 when the accumulator pressure detecting means is abnormal will be described with reference to the flowchart of FIG. In the abnormal accumulator pressure detecting means control routine 1, S201 is first executed to read the wheel cylinder pressure which is the hydraulic pressure of the wheel cylinders 26, 28, 42 and 44 and the voltage of the motor 78 which drives the pump 80. Next, in S202, the accumulator pressure estimated value is calculated from the wheel cylinder pressure and the motor voltage by a method similar to the abnormality detection routine of the accumulator pressure detection means. Next, in S203, it is determined from the voltage value of the motor 78 whether or not the pump 80 is being driven. If NO, S204
Proceed to. If YES, the process proceeds to S206. In S204, it is determined whether the accumulator pressure estimated value is less than or equal to the threshold value X2. If NO, the process proceeds to S205 and the pump 80 is not driven. If YES, the process proceeds to S209 to drive the pump 80. In S206, it is determined whether the accumulator pressure estimated value is the threshold value X3 or more,
If NO, the process proceeds to S207, and the pump 80 remains driven. If YES, proceed to S208, where pump 80
Stop driving.

Next, the control routine 2 when the accumulator pressure detecting means is abnormal will be described with reference to the flowchart of FIG. In the control routine 2 when the accumulator pressure detecting means is abnormal, first, S301 is executed to measure the wheel cylinder pressure which is the hydraulic pressure of the wheel cylinders 26, 28, 42 and 44, the voltage of the motor 78 which drives the pump 80, and the proportional electromagnetic. Command values for the drive circuits of the hydraulic pressure control valves 58, 60, 62, 64 are read. Next, in S302,
From the command value to the drive circuit of the proportional electromagnetic hydraulic pressure control valves 58, 60, 62, 64, the wheel cylinders 26, 28, 4
The wheel cylinder pressure estimated value, which is the estimated value of the hydraulic pressure of 2,44, is calculated. Next, in S303, it is determined whether or not (wheel cylinder pressure estimated value-wheel cylinder pressure measured value)> X4 (threshold value), and if NO, the process proceeds to S304. YE
In the case of S, the routine is terminated, and the electromagnetic directional control valve 5
The solenoids 0, 52, 54, 56, 84, 86 are excited and switched to the positions opposite to the original position shown in FIG. 1, and the hydraulic pressure of the wheel cylinders 26, 28, 42, 44 is changed to the master cylinder 12 It is mechanically controlled based on the hydraulic pressure of. In S304, the accumulator pressure estimated value is calculated from the wheel cylinder pressure and the motor voltage by the same method as the abnormality detection routine of the accumulator pressure detection means. Next, in S305, it is determined whether or not the pump 80 is being driven from the voltage value of the motor 78, and if NO, S306.
Proceed to. If YES, the process proceeds to S308. In S306, it is determined whether the accumulator pressure estimated value is equal to or less than the threshold value X2. If NO, the process proceeds to S307 and the pump 80
Leave undriven. If YES, the process proceeds to S311 to drive the pump 80. In S308, it is determined whether the accumulator pressure estimated value is the threshold value X3 or more,
If NO, the process proceeds to S309, and the pump 80 remains driven. If YES, the process proceeds to S310, where the pump 80
Stop driving.

According to the first embodiment, the hydraulic pressure of the accumulator 70 is detected by calculating the accumulator pressure estimated value from the wheel cylinder pressure of each wheel and the motor voltage and comparing it with the measured accumulator pressure value. Pressure sensor 1
When it is possible to detect the abnormality of 16 and the abnormality of the hydraulic pressure sensor 116 that detects the hydraulic pressure of the accumulator 70 is detected, the control for driving the pump 80 is based on the accumulator pressure measurement value. Since the change is made based on the estimated pressure value, even when an abnormality occurs in the hydraulic pressure sensor 116 that detects the hydraulic pressure of the accumulator 70,
An advantage is that an electrically controlled hydraulic brake can be maintained without switching to a mechanical brake that supplies hydraulic pressure from the master cylinder 12 directly to the wheel cylinders 26, 28, 42, 44.

A second embodiment is shown in FIGS. 6 to 8. Only the points different from the first embodiment will be described below. A hydraulic switch 136 is provided as means for detecting the hydraulic pressure of the accumulator 70. The hydraulic switch 136
As in the characteristic shown in FIG. 7, the state changes depending on the hydraulic pressure of the accumulator 70. When the accumulator pressure falls below the threshold value X2, the state of the hydraulic pressure switch 136 changes from state 1 to state 2, the pump 80 is driven, and when the accumulator pressure rises above the threshold value X3, the state of the hydraulic pressure switch 136 changes to state 2. Changes to state 1 from
The drive of the pump 80 is stopped, and the accumulator 70 stores liquid at a liquid pressure within a certain range.

Next, the operation will be described with reference to the flowchart of FIG. However, the flowchart of the wheel rotation suppression routine is the same as that in the first embodiment, and will be omitted.
FIG. 8 is a flow chart of a routine for detecting an abnormality of the fluid pressure switch 136 which is the fluid pressure detecting means of the accumulator 70. This routine is performed at regular intervals regardless of whether braking is being performed. First, S401 is executed and the initial value of the counter C is set to 0. Next, S402 is executed, and the wheel cylinder pressure, which is the hydraulic pressure of the wheel cylinders 26, 28, 42, and 44, and the voltage of the motor 78 that drives the pump 80 are read. Next, in S403, the wheel cylinder pressure and the motor voltage are used to determine the first embodiment.
The accumulator pressure estimated value is calculated in the same manner as above, and the hydraulic switch estimation means is obtained. Next, in S404, the hydraulic switch measurement state is read by the hydraulic switch 136 that detects the hydraulic pressure of the accumulator 70. Next, S405 is executed, and it is determined whether the estimated state of the hydraulic switch and the measured state of the hydraulic switch are the same state. If YES, the routine execution ends. If NO, the process proceeds to S406 and the value of the counter C is incremented by 1. Next, in S407, it is determined whether the value of the counter C exceeds the threshold value Z. NO
In the case of, it returns to S402. In the case of YES, the processing proceeds to S408, in which it is measured whether or not the fluid pressure switch measurement state is the state 1 in FIG. 7, and in the case of YES, the routine is finished,
The control routine 1 at the time of abnormality of the accumulator pressure detecting means similar to that of the first embodiment is executed. If this routine is executed, it is repeated at regular intervals regardless of whether braking is being performed. If NO, the routine is terminated and the accumulator pressure detecting means abnormal time control routine 2 similar to that of the first embodiment is executed. If this routine is also executed, it is repeated at regular intervals regardless of whether braking is being performed.

Therefore, in the second embodiment, the same operation and effect as those in the first embodiment can be obtained, and the accumulator 70 is also provided.
Since the hydraulic pressure switch 136 is used as a means for detecting the hydraulic pressure of, the advantage that the electric control type hydraulic brake system can be maintained at a lower cost and the reliability of the electric control type hydraulic brake system can be improved. There is.

FIG. 9 shows the third embodiment. The configuration of the third embodiment is similar to that of the first embodiment.

Next, the operation will be described with reference to the flowchart of FIG. 9, but since the processing from S501 to S505 is the same as S101 to S105 in FIG. 3, the description thereof will be omitted and only the points different from the first embodiment will be described. To do. S505
If NO, the process proceeds to S506 to determine whether the accumulator pressure measurement value is equal to or greater than the threshold value X3 and the pump 80 is not driven, and if NO, the execution of the routine ends. If YES, the process proceeds to S507, and the accumulator pressure measured value is substituted into the accumulator pressure estimated value.

According to the third embodiment, since the hydraulic pressure sensor 116 for detecting the accumulator pressure has no abnormality and the pump 80 resets the accumulator pressure estimated value in the state where the liquid is most accumulated in the accumulator 70, It is possible to reduce the error in the accumulator pressure estimated value. Therefore, in the third embodiment as well, the same operational effects as in the first embodiment are obtained, and the error in the estimated value of the hydraulic pressure of the accumulator 70 is reduced, so that the reliability of the electrically controlled hydraulic brake system is increased. There is.

FIG. 10 shows the fourth embodiment. The configuration of the fourth embodiment is similar to that of the second embodiment.

Next, the operation will be described with reference to the flowchart of FIG. 10. However, since the processing from S601 to S605 is the same as that from S401 to S405 in FIG.
Only the points different from the second embodiment will be described. S60
If YES is obtained in step 5, the process proceeds to step S609, and it is determined whether the accumulator pressure estimated value is equal to or larger than the threshold value X3 and the pump 80 is not driven. If NO is determined, the execution of the routine ends. If YES, the process proceeds to S610, and the threshold value X3 is assigned to the accumulator pressure estimated value.

According to the fourth embodiment, since the hydraulic switch 136 for detecting the accumulator pressure has no abnormality and the pump 80 resets the accumulator pressure estimated value in the state in which the liquid is most accumulated in the accumulator 70,
It is possible to reduce the error in the accumulator pressure estimated value. Therefore, in the fourth embodiment as well, the same operational effect as in the second embodiment is obtained, and the error in the estimated state of the hydraulic switch 136 for detecting the hydraulic pressure of the accumulator 70 is reduced, so that the electrically controlled hydraulic brake system is provided. Has the advantage of increasing reliability.

[0028]

As described above, according to the first aspect of the present invention, the hydraulic pressure of the hydraulic pressure source is obtained from the detected amount of the wheel cylinder pressure detecting means and the command value of the pump drive control means. By comparing with the detection amount of the hydraulic pressure source hydraulic pressure detection means, it is possible to detect an abnormality of the hydraulic pressure source hydraulic pressure detection means, and when an abnormality of the hydraulic pressure source hydraulic pressure detection means is detected, Since the pump drive control means is changed to control based on the estimated amount of the hydraulic pressure source hydraulic pressure estimation means, even if an abnormality occurs in the hydraulic pressure source hydraulic pressure detection means, the hydraulic pressure from the master cylinder is directly applied to the wheel cylinders. It is possible to maintain the electrically controlled hydraulic brake without switching to the mechanical brake to be supplied. According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, a hydraulic switch is used to detect the hydraulic pressure of the hydraulic pressure source, and even if an abnormality of the hydraulic switch occurs, an electric control type is used. Since the hydraulic brake can be maintained, it is possible to obtain an effect that the electric controlled hydraulic brake can be maintained at a lower cost and the reliability of the electrically controlled hydraulic brake is improved. According to the invention of claim 3,
In addition to the effect of the invention as set forth in claim 1, the estimated amount of the hydraulic pressure source hydraulic pressure estimating means is reset in a state where there is no abnormality in the hydraulic pressure source hydraulic pressure detecting means and the liquid is most stored in the hydraulic pressure source. By doing so, the error in the estimated amount of the hydraulic pressure source hydraulic pressure estimating means is reduced, so that the reliability of the electrically controlled hydraulic brake is enhanced. According to the invention of claim 4, in addition to the effect of the invention of claim 2, there is no abnormality in the fluid pressure source fluid pressure switch, and the fluid is most accumulated in the fluid pressure source,
By resetting the estimated amount of the hydraulic pressure source hydraulic pressure estimation means, the error of the estimated amount of the hydraulic pressure source hydraulic pressure estimation means is reduced, and thus the reliability of the electrically controlled hydraulic brake is further enhanced. To be

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of first and third embodiments of the present invention.

FIG. 2 is a flowchart showing a wheel rotation suppression routine in the first to fourth embodiments.

FIG. 3 is a flowchart showing an abnormality detection routine of accumulator pressure detection means in the first embodiment.

FIG. 4 is a flowchart showing an accumulator pressure detecting means abnormal control routine 1 in the first to fourth embodiments.

FIG. 5 is a flowchart showing an accumulator pressure detecting means abnormal control routine 2 in the first to fourth embodiments.

FIG. 6 is a diagram showing a configuration of second and fourth embodiments.

FIG. 7 is a diagram showing a state of a hydraulic switch that is accumulator pressure detecting means in the second and fourth embodiments.

FIG. 8 is a flowchart showing an abnormality detection routine of accumulator pressure detection means in the second embodiment.

FIG. 9 is a flowchart showing an abnormality detection routine of accumulator pressure detection means in the third embodiment.

FIG. 10 is a flowchart showing an abnormality detection routine of accumulator pressure detection means in the fourth embodiment.

[Explanation of symbols]

10 brake pedal 12 Master cylinder 14 liquid passage 16 liquid passage 18 branch passages 20 branch passages 22 left front wheel 24 right front wheel 26 front wheel cylinder 28 front wheel cylinder 30 liquid passage 32 liquid passage 34 branch passage 36 branch passages 38 left rear wheel 40 right rear wheel 42 Rear wheel cylinder 44 Rear wheel cylinder 46 Proportioning valve 50 electromagnetic directional valve 52 Electromagnetic directional control valve 54 Electromagnetic directional control valve 56 Electromagnetic directional valve 58 Proportional electromagnetic hydraulic control valve 60 Proportional electromagnetic hydraulic control valve 62 Proportional electromagnetic hydraulic control valve 64 Proportional electromagnetic hydraulic control valve 70 Accumulator 72 Reservoir 74 Liquid passage 76 Liquid passage 78 motor 80 pumps 84 Electromagnetic directional control valve 86 Electromagnetic directional control valve 88 Stroke Simulator 90 Stroke Simulator 100 control device 102 CPU 104 ROM 106 RAM 108 Input section 110 Output section 112 Brake switch 114 Treading force detector 116 Liquid pressure sensor 118 Liquid pressure sensor 120 Liquid pressure sensor 122 Liquid pressure sensor 124 Liquid pressure sensor 126 Wheel speed sensor 128 wheel speed sensor 130 Wheel speed sensor 132 Wheel speed sensor 136 hydraulic switch 144 front and rear G sensor 146 Horizontal G sensor

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Claims (4)

[Claims] 1. A brake operation member, an operation amount detection means for detecting an operation amount of the brake operation member, a hydraulic pressure source including a pump, and a hydraulic pressure source hydraulic pressure detection for detecting the hydraulic pressure of the hydraulic pressure source. Means, pump drive control means for controlling drive of the pump based on the detection amount of the hydraulic pressure source hydraulic pressure detection means, a plurality of wheel cylinders for respectively suppressing rotation of a plurality of wheels, and the plurality of wheel cylinders A plurality of wheel cylinder pressure detecting means for detecting the respective hydraulic pressures, a plurality of liquid passages respectively connecting the hydraulic pressure source and the plurality of wheel cylinders, and the wheel cylinders provided in each of the liquid passages. A brake fluid pressure control device including a plurality of fluid pressure control devices for controlling fluid pressure, and a fluid pressure control device control means for controlling the fluid pressure control device based on the detection amount of the operation amount detection means. A hydraulic pressure source hydraulic pressure estimating means for estimating the hydraulic pressure of the hydraulic pressure source from the detected amount of the wheel cylinder pressure detecting means and a command value of the pump drive control means, and a command of the hydraulic pressure control device control means. A wheel cylinder pressure estimating means for estimating the hydraulic pressure of the wheel cylinder from a value, and a difference between the detected amount of the hydraulic pressure source hydraulic pressure detecting means and the estimated amount of the hydraulic pressure source hydraulic pressure estimating means is first. Is exceeded, or the difference between the estimated amount of the hydraulic pressure source hydraulic pressure estimating means and the detected amount of the hydraulic pressure source hydraulic pressure detecting means exceeds a first threshold and the wheel cylinder pressure estimating means estimates the same. The pump drive control so as to drive the pump based on the estimated amount of the hydraulic pressure source hydraulic pressure estimating unit when the difference between the amount and the detected amount of the wheel cylinder pressure detecting unit does not exceed a second threshold value. Brake fluid pressure characterized by changing means Control device. 2. A brake operating member, an operation amount detecting means for detecting an operation amount of the brake operating member, a hydraulic pressure source including a pump, and two states depending on the hydraulic pressure of the hydraulic pressure source. The fluid pressure source fluid pressure switch that switches, and the pump that does not drive the pump when the fluid pressure source fluid pressure switch is in the first state and drives the pump when in the second state A pump drive control means for controlling the drive of the plurality of wheel cylinders, a plurality of wheel cylinders for respectively suppressing the rotation of a plurality of wheels, a plurality of wheel cylinder pressure detection means for detecting the hydraulic pressure of each of the plurality of wheel cylinders, A plurality of liquid passages respectively connecting the pressure source and the plurality of wheel cylinders, and a plurality of hydraulic pressure control devices provided in each of the liquid passages for suppressing the hydraulic pressure of the wheel cylinders,
A brake fluid pressure control device including a fluid pressure control device control means for controlling the fluid pressure control device based on the detection amount of the operation amount detection means, wherein the detection amount of the wheel cylinder pressure detection means and the pump drive control means Hydraulic pressure source hydraulic pressure estimating means for estimating the hydraulic pressure of the hydraulic pressure source and the state of the hydraulic pressure source hydraulic pressure switch from the command value of, and the hydraulic pressure of the wheel cylinder from the command value of the hydraulic pressure control device control means. Wheel cylinder pressure estimating means for estimating a pressure, wherein the switch estimation state of the hydraulic pressure source hydraulic pressure estimating means and the state of the hydraulic pressure source hydraulic pressure switch differ for a time period exceeding a third threshold value, and When the state of the pressure source hydraulic pressure switch is the first state, or when the switch estimated state of the hydraulic pressure source hydraulic pressure estimating means and the state of the hydraulic pressure source hydraulic pressure switch are different for a time exceeding the third threshold value, And the liquid pressure If the source fluid pressure switch is in the second state and the difference between the estimated amount of the wheel cylinder pressure estimating means and the detected amount of the wheel cylinder pressure detecting means does not exceed the second threshold value, A brake fluid pressure control device, wherein the pump drive control means is changed so as to drive the pump based on the estimated amount of the pressure source fluid pressure estimation means. 3. The brake hydraulic pressure control device according to claim 1, wherein an absolute value of a difference between a detected amount of the hydraulic pressure source hydraulic pressure detecting means and an estimated amount of the hydraulic pressure source hydraulic pressure estimating means is a first value. When the detected amount of the hydraulic pressure source hydraulic pressure detection unit is equal to or greater than a fourth threshold value and the pump is not driven, the estimated amount of the hydraulic pressure source hydraulic pressure estimation unit is set to the above-described estimated amount. A brake fluid pressure control device, wherein a detection amount of a fluid pressure source fluid pressure detection means is substituted. 4. The brake fluid pressure control device according to claim 2, wherein the switch estimated state of the fluid pressure source fluid pressure estimation means and the state of the fluid pressure source fluid pressure switch are equal to each other, and the fluid pressure source. When the estimated amount of the hydraulic pressure estimating means is equal to or larger than a fourth threshold value and the pump is not driven, the fourth threshold value is substituted into the estimated amount of the hydraulic pressure source hydraulic pressure estimating means. Brake fluid pressure control device.