JP2000219129A - Brake control device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In a device having a dual hydraulic configuration, a valve that assists normal brake control, a valve that is not used or is used less frequently in normal brake control, or
An abnormality determination of a valve used when a hydraulic system performing a normal braking operation fails is performed in an appropriate state. SOLUTION: Solenoids SOL1,3,5,7 which supply brake pressure to wheel cylinder W / C by pressure from pressure supply sources ACC1 and ACC2 to increase pressure and solenoid SOL which reduces brake pressure of brake device.
Brake control device 10 in which 2, 4, 6, and 8 are dual systems
0, one of the booster valves (SOL3,
7) is operated for a predetermined period of time, and abnormality in pressure increase and pressure reduction of the hydraulic system is detected based on a change in oil pressure before and after the operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake control device and, more particularly, to abnormality detection of a brake control device having a double pressure boosting valve and a pressure reducing valve.

[0002]

2. Description of the Related Art Conventionally, a vehicle detects a preceding vehicle by a laser radar, an ultrasonic sensor, or the like, and travels while maintaining a safe distance from the preceding vehicle. Automatic braking control devices that automatically apply brakes to the wheels when the vehicle is running or when it is determined that the vehicle collides with a preceding vehicle or an obstacle during traveling are known. ,
For example, it is disclosed in JP-A-6-107141.

In the device disclosed in this publication, a shut-off valve is provided between a master cylinder and a brake device (wheel cylinder) to shut off communication with the master cylinder. When the shut-off valve is in an open position, the brake pedal is depressed. The braking force acts on the brake device of each wheel according to the force, and during automatic brake control (when the shut-off valve is in the closed position), the brake pressure is supplied from the pressure supply source of the automatic brake device to each wheel via the pressure increasing valve. Is supplied to the brake device. In this device, further, in order to secure the brake pressure even when the booster valve of the automatic brake device fails, a pressure supply source for the failure and a booster valve are provided in parallel with the hydraulic system of the automatic brake device, Even when the booster valve of the automatic brake device fails (when the brake pressure does not increase to the set pressure during the automatic brake operation), the brake pressure is supplied to the brake device of each wheel from the fail pressure supply source. Has taken. in this case,
In the failure judgment of the hydraulic system, the pressure is supplied from the pressure supply source for the failure, the valve is driven, and the failure of the pressure reducing valve is determined based on whether the pressure can be maintained and the pressure can be reduced. The pump failure and the booster valve failure are determined based on whether the pressurization is possible.

In Japanese Unexamined Patent Publication No. Hei 5-310119, when the engine is started while the vehicle is parked, if the cooling water temperature is lower than 30 ° C., the brake pressure of the automatic brake is determined, and the hydraulic pressure is determined. A method of detecting system abnormalities is used to improve system reliability.

[0005]

However, Japanese Unexamined Patent Publication No. Hei 6-107141 discloses that an emergency hydraulic pressure is supplied to a brake device when the brake pressure does not reach a set pressure during an automatic brake operation. And a pressure reducing valve,
Pump failure and pressure valve failure can be determined.However, when the set pressure is reached during automatic brake operation, only the emergency hydraulic pressure supply is stopped, and there is no disclosure about abnormality determination whether the fail-safe valve is normal. Absent.

[0006] Further, since the operation disclosed in Japanese Patent Application Laid-Open No. Hei 5-310119 is performed when the start of the engine is detected while the vehicle is parked, abnormality determination of the hydraulic system is not performed after the start of the engine. It is impossible to detect a hydraulic system abnormality that occurs during traveling or the like that occurs later.

In particular, by using a pressure-intensifying valve for increasing / decreasing the pressure in the brake device and a valve (emergency valve) which is not operated in a normal state other than the pressure-reducing valve, an obstacle (preceding vehicle, object) is taken according to the surrounding situation. If a sudden deceleration request is issued in order to avoid collisions and the brakes are forcibly applied instantaneously to the vehicle, the above determination method cannot cope with the It is necessary to detect abnormalities.

Therefore, the present invention has been made in view of the above problems, and in a device having a dual hydraulic configuration, a valve for assisting normal brake control, is not used in normal brake control. Or infrequently used valves,
Alternatively, it is a technical object to perform abnormality determination of a valve used when a hydraulic system performing a normal braking operation fails in an appropriate state.

[0009]

A first technical measure taken to solve the above-mentioned problem is that a hydraulic pressure supplied from a pressure supply source (ACC1 / 2) to a wheel brake device (W / C). A pair of hydraulic control valves (SOL1 to SOL8) for controlling hydraulic pressure,
Each time the vehicle stops (S301), one of the hydraulic control valves (SOL
1/5, SOL3 / 7) for a predetermined period of time, and an abnormality in the hydraulic system is detected based on a change in hydraulic pressure before and after the brake operation (S306, 309) (S308, 31).
1).

According to this, one of the pressure-intensifying valves is operated for a predetermined time each time the vehicle stops, and abnormality of the hydraulic system is detected based on a change in hydraulic pressure before and after the operation, so that abnormality detection can be performed every time the vehicle stops. Because it is possible, in a device with a dual hydraulic configuration, a valve that assists normal brake control,
Even if a valve that is not used or used infrequently in normal brake control, or has a valve that is used when the hydraulic system that performs normal brake operation fails, make an abnormality judgment in an appropriate state Becomes possible.

Further, a pair of hydraulic control valves are operated as normal hydraulic control valves (SOL 1/5, S
OL2 / 6) and an emergency hydraulic control valve (SOL3 / 7, SO
L4 / 8), and every time the vehicle stops, the emergency hydraulic control valve (SOL3 / 7) is operated to increase the pressure, and the abnormality in the hydraulic system is detected by the change in hydraulic pressure before and after the brake operation (S306, 309). (S308, 311).

According to this, the emergency hydraulic pressure control valve (emergency valve) used at the time of a failure is actuated every time the vehicle stops, and the abnormality of the hydraulic system is detected by the change in the oil pressure before and after the operation. This is performed every time the vehicle stops, and abnormality detection can be performed periodically. Therefore, in a device having a double hydraulic configuration, a valve that assists normal brake control, is not used in normal brake control, or Even if a valve that is used less frequently, or a valve that is used when a hydraulic system that performs a normal brake operation fails, the abnormality determination can be performed in an appropriate state.

That is, in this brake control device, the stop state detecting means (S301) and the stop-time pressure increasing valve operating means (S301)
304), before and after operation pressure comparison means (S306, S30)
9) It is desirable to have a hydraulic system abnormality detecting means (S308, S311).

Further, it is preferable to include a stop state detecting means (S301), a stop emergency valve operating means (S308, S311), and a hydraulic system abnormality detecting means (S308, S311).

The figures and step numbers of the corresponding elements shown in the drawings and described later are added in the parentheses for reference.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the system configuration of the present invention, in which the FR wheel and the RL wheel (FR-RL system), the FL wheel and the RR wheel (FL-RR system) adopt X piping, the front wheel and the rear wheel. Between them, proportioning valves PV1 and PV2 for suppressing the brake pressure of the rear wheels with respect to the front wheels are provided.

The control hydraulic system (hereinafter referred to as hydraulic system)
Pressure sensors P1 and P2 for detecting oil pressure applied to a wheel cylinder (brake device) W / C provided on each wheel of the R-RL system and the FL-RR system are provided, and information from the sensors P1 and P2 is provided. Based on the solenoid (SO
L) is supplied / discharged (on / off) to supply brake fluid to the wheel cylinders of the respective wheels or discharge the brake fluid to the reservoirs RV1 and RV2, thereby performing brake pressure control. SOLs 1 to 8 used here are normally-closed solenoid valves.
Is turned on (energized) to connect the inlet and the outlet.

(FR-RL system) A brake pressure is supplied from an accumulator (ACC1) serving as a pressure supply source to the FR-RL system via a pressure regulating valve AV1 and SOL1 for reducing the pressure to a constant pressure. An orifice OF1 is provided between the ACC1 and the pressure regulating valve AV1, and a filter FL1 for preventing the passage of foreign matter to the orifices OF2 and SOL1 is interposed between the pressure regulating valve AV1 and SOL1.

The pressure of the brake fluid supplied to the wheels of the FR-RL system (discharge to the reservoir RV1) is increased by SOL2
By turning on SOL2, the brake fluid is released to the reservoir RV1 through the orifice OF3, and the brake pressure applied to the wheels can be reduced.

The brake fluid stored in the reservoir RV1 is pumped up by the drive of the pump motor PM1, and is stored in the accumulator ACC1 at a high pressure. In this case, between the reservoir RV1 and the pump PP1, a check valve CV11 and a filter FL11 for preventing the flow of foreign matter in the pipe are provided so that the brake fluid flows only from the reservoir RV1 to the pump side. ACC is provided between the pump PP1 and the ACC1.
A check valve CV1 through which brake fluid flows is provided only on one side, and a relief valve RR1 that releases to the reservoir RV1 when the pressure of the ACC1 becomes higher than a predetermined pressure is provided between the ACC1 and the reservoir RV1. It is provided in.

Further, SOL3 for operating SOL1 in an assist or fail-safe manner is provided, and SOL4 for operating SOL2 in an assist or fail-safe manner is provided.
L3 sets the pressure of ACC1 to orifice OF1 and SOL.
A pressure increasing solenoid which is supplied to the FR-RL system via a filter FL11 for preventing foreign matter from passing to the third side. Further, when SOL2 fails, SOL4 is a pressure reducing solenoid that releases the brake pressure supplied to the FR-RL system to RV1 and reduces the pressure.

(FL-RR system) A brake pressure is supplied from an accumulator (ACC2) as a pressure supply source to the FL-RR system via a pressure regulating valve AV2 and SOL5 for reducing the pressure to a constant pressure. In addition, an orifice OF4 is provided between the ACC2 and the pressure regulating valve AV2, and a filter FL2 for preventing the passage of foreign matter to the orifices OF5 and SOL5 is interposed between the pressure regulating valve AV2 and SOL5.

The brake fluid supplied to the wheels of the FL-RR system is reduced in pressure (discharged to the reservoir RV2) by SOL6.
When the SOL 6 is turned on, the brake fluid is released to the reservoir RV2 through the orifice OF6, and the brake pressure applied to the W / C of the wheels can be reduced.

The brake fluid stored in the reservoir 2 is pumped up by driving the pump motor PM2, and is stored in the accumulator ACC2 at a high pressure. In this case, between the reservoir RV2 and the pump PP2, a check valve CV22 and a filter FL22 for preventing the flow of foreign matter in the pipe are provided so that the brake fluid flows only from the RV2 to the pump side. A check valve CV2 through which the brake fluid flows only on the ACC2 side is provided between the pump PP2 and the ACC2. Further, when the pressure of the ACC2 becomes higher than a certain pressure, a relief valve is released to the reservoir RV2. Valve RR2
Is provided between the ACC2 and the reservoir RV2.

Further, a SOL 7 for operating the SOL 5 in an assist or fail-safe manner is provided, and a SOL 8 for operating the SOL 6 in an assist or fail-safe manner is provided.
L7 adjusts the pressure of ACC2 to orifice OF4 and SOL.
A solenoid for increasing pressure supplied to the FL-RR system via a filter FL22 for preventing passage of foreign matter to the side 7. When SOL6 fails, SOL8 is a pressure reducing solenoid that releases the brake pressure supplied to the FL-RR system to RV2 and reduces the pressure, and the hydraulic system can perform brake control independently for diagonal wheels. That is, in this configuration, in consideration of the fail-safe of the hydraulic system, the pressure-increasing and pressure-reducing solenoids have a sub-hydraulic system with respect to the main hydraulic system.
When SOL1 and SOL2 are normal, FR-RL
When the brake pressure is increased (pressure increase control is performed) in the system, the brake pressure is increased by turning on SOL1 using the accumulated pressure of ACC1 as a supply source. When the brake pressure is reduced (pressure reduction control is performed), the brake fluid is released to RV1 by turning off SOL1 and turning on SOL2 to reduce the pressure applied to the wheel cylinder W / C.

When SOL5 and SOL6 are normal, FL-RR
When increasing the brake pressure (performing pressure increase control) in the system, the brake pressure is increased by turning on SOL5 using the accumulated pressure of ACC2 as a supply source, and the brake pressure is reduced (pressure reduction). Control)
In this case, SOL5 is turned off and SOL6 is turned on to release the brake fluid to RV2 and reduce the pressure.
Further, holding control can be performed by turning off both SOL1 to SOL8 for increasing and decreasing the pressure. In this case, for example, when the accumulator pressures of ACC1 and ACC2 are set to 150 kgf / cm ² , pressure regulating valves AV1 and A
Since the pressure is reduced to 30 to 40 kgf / cm ² by V2, a higher pressure is supplied to the sub-hydraulic system that does not pass through the pressure regulating valves AV1 and AV2 than the main hydraulic system that passes through the pressure regulating valves AV1 and AV2. I have.

Next, referring to FIG.
The connection relationship between the controller 00 and the controller 3 will be described.
Power is supplied from the battery BT of the vehicle via an ignition switch IG SW to the controller 3 that controls the automatic brake control. The power is supplied to the controller 3 by turning on the IG SW.

The controller 3 receives information from a vehicle speed sensor 4 for detecting a vehicle speed. This vehicle speed information only needs to know the speed of the vehicle, and the signal may be obtained from a rotation signal from rotation of a gear of the transmission or a signal from a wheel speed sensor rotating during traveling. Further, the controller 3 includes the FR-RL system and the FL-RR
Pressure sensors (wheel cylinder pressure sensors) P1 and P2 for detecting the hydraulic pressure applied to the wheel cylinders of the system, a G sensor 7 for detecting the acceleration / deceleration applied to the vehicle when the vehicle is running, and the fluid amounts of reservoirs RV1 and RV2 for storing the brake fluid. Oil level sensors LVL1 and LVL2 that detect the state of the preceding vehicle using a laser, ultrasonic waves, or the like, and a target calculated based on information of a stop position to stop on a predetermined traveling road surface. The deceleration information is input from the vehicle control computer CPT.

Here, the brake control device 100 runs several vehicles in a predetermined circuit, and detects a preceding vehicle in front of the own vehicle by a detection sensor such as a laser or an ultrasonic wave. However, the present invention is applied to a case in which the circuit runs automatically in a specific running pattern, but is not limited to this.

The controller 3 determines the FR-RL solenoids SOL1 to SOL1 based on the input information (signal).
4. While operating the pump motor PM1, the FL-R
When the solenoids SOL5 to SOL8 of the R system and the pump motor PM2 are operated, and an abnormality occurs in these hydraulic systems, an external notification is made by a buzzer BZ in order to inform the occupant of the abnormality. When the vehicle is to be stopped, stop holding information (stop holding flag) is sent.

Next, the processing of the controller 3 will be described with reference to FIG. When power is supplied by IG ON, the controller 3 executes the flowchart shown in FIG. First, initial processing is performed in step S101. Here, the ROM and R in the controller are
The AM is checked, an initial value is set in a memory required for processing, and then a check is made to determine whether the controller 3 operates normally. In step S102, input processing of a signal input to the controller 3 is performed, and the vehicle speed sensor 4, the W / C pressure sensors P1 and P2, the acceleration / deceleration (G)
Signals from the sensor 7 and the oil level sensors LVL1 and LVL2 are input and stored in a necessary memory. Step S1
At 03, the vehicle speed of the own vehicle is obtained by the vehicle speed calculation processing based on the vehicle speed signal (vehicle speed pulse) from the vehicle speed sensor 4, and then
In step S104, the vehicle control computer CPT
The target deceleration is input from. The target deceleration is
Although the information is obtained from the vehicle control computer CPT based on the predetermined stop position on the traveling road surface and the vehicle speed of the own vehicle, the information is not limited thereto, and the vehicle speed sensor 4, the G sensor 7, and the W / C pressure sensor P1 are obtained. , P2, etc., the target deceleration may be determined inside the controller.

Next, in step S105, a failure determination is made. This failure determination determines a failure of the main hydraulic system flowing through the pressure regulating valves AV1 and AV2. Specifically, the wheel cylinder W / of the diagonal wheel when the pressure increase, pressure decrease, and holding control are not performed by the automatic brake control.
The oil pressure of C is detected by the pressure sensors P1 and P2, and the pressure at that time is stored in a predetermined memory. Thereafter, the pressure is increased S
OL1 and SOL5 are operated to increase the pressure in the main hydraulic system, the pressure after the increase is stored in another predetermined memory, the pressure difference before and after the increase is obtained, and then the pressure is increased in a normal state. By comparing the obtained predetermined value (a value stored in the memory in advance) with the pressure deviation and determining an abnormality, an abnormality of the pressure increasing system can be known. Further, the abnormality of the pressure reducing system is based on the state in which the pressure is applied to the wheel cylinder W / C, and SOL2 and SOL6 for reducing the pressure of the main hydraulic system are operated, and P1, P2
An abnormality in the pressure reducing system is detected based on whether or not the pressure decreases. In this case, when the hydraulic system is abnormal, an abnormal flag is set.

Thereafter, it is determined whether or not an abnormality has occurred in the hydraulic system based on an abnormality flag set in the case where an abnormality has occurred in the failure determination in step S106. S1
At 08, backup control is performed. The backup control here is performed when the FR-RL system has an abnormal pressure increase.
The pressure is increased by turning on SOL3 in place of OL1, and if the pressure is abnormal, SO is replaced instead of SOL2.
Turn on L4. When the FL-RR system has a pressure increase abnormality, the pressure is increased by turning on SOL7 instead of SOL5. When the pressure increase is abnormal, SOL8 is turned on instead of SOL6. As a result, it is possible to secure an optimal braking force for the W / C so that the target deceleration sent from the vehicle control computer CPT is achieved by using the dual hydraulic configuration. If an error occurs, buzzer B
By sounding Z, an occupant can be notified of an abnormality to notify that a failure has occurred.

On the other hand, if there is no abnormality in step S106, the automatic brake control shown in FIG. 4 is performed in step S107. Here, in step S201, the state of the stop holding flag first sent from the vehicle control computer CPT is checked. When the stop holding flag is on (when stopping the vehicle is held), stop holding control is performed in step S207. In the stop holding control, the SOL on the pressure increasing side and the SOL on the pressure reducing side are turned off to maintain the pressure applied to the wheel cylinder W / C, and in step S208, a failure determination of a sub hydraulic system described later is performed. To end.

However, if the stop holding flag is OFF in step S201, it is determined in step S202 whether the target current speed Gt sent from the vehicle control computer CPT is not zero (no request for automatic brake control). If the target deceleration Gt is not zero, the process from step S203 is executed. If the target deceleration Gt is zero, the process proceeds to step S209.

In step S203, since the deceleration request has been issued from the vehicle control computer CPT, the automatic brake control flag is turned on to start the automatic brake control. Then, in step S204, the current deceleration Gc
Is input from the G sensor 7 and captured. Thereafter, in step S205, the deviation between the target deceleration Gt and the current deceleration Gc is compared with a predetermined deceleration ΔG1 (for example, 0.03G).
SOL5 such as SOL5 is activated and the diagonal wheel (FR
-RL system and FL-RR system).

However, when the deviation (Gt-Gc) is equal to or smaller than the predetermined deceleration ΔG1, Gt-Gc is obtained in step S213, and the deviation is compared with -G1. Here, if the value of Gt−Gc is smaller than −ΔG1, in step S214, the decompression SOL such as SOL2 and SOL6 is operated, and the diagonal wheels (FR-RL system and F
(L-RR system), the value of Gt-Gc is-
If ΔG1 or more, in step S215, SOL1, SOL5 on the pressure increasing side and SOL2, SOL6 on the pressure decreasing side of the main hydraulic system are not operated, and the diagonal wheel (FR−
RL system and FL-RR system).

On the other hand, if the target deceleration sent from the vehicle control computer CPT is zero in step S202, the automatic brake control in progress flag is turned off (cleared) in step S209 to end the automatic brake control. . Thereafter, the W / C pressure is detected again, and in step S210, the pressure of the FR-RL system is stored in P12 and the pressure of the FL-RR system is stored in P22. In step S211, the stored pressure P1
2. It is determined whether or not P22 is zero. If the pressure at P12 and P22 is zero (when no pressure is applied to the wheel cylinder W / C), no pressure is applied to the wheel cylinder W / C. This process is terminated without releasing the pressure. However, when the pressure of P12 and P22 is not zero and the pressure is applied to the wheel cylinder W / C, the SOL for reducing the pressure is operated, and the pressure applied to the wheel cylinder W / C is transferred to the reservoirs RV1 and RV2. Release and release the automatic brake.

Next, the failure determination of the sub-hydraulic system shown in step S208 of FIG. 4, which is a feature of the present invention, will be described. In step S301, it is determined whether the vehicle is stopped (vehicle speed is zero). Here, if the vehicle speed is not zero, the failure determination end flag of the sub-hydraulic system is turned off in step S313, and then this processing ends.
If the vehicle is stopped (the vehicle speed is zero), the state of the sub hydraulic system failure determination end flag indicating whether the sub hydraulic system failure determination has been completed is checked in step S302. Here, if the flag is set, this process is terminated. However, if the sub hydraulic system failure determination termination flag is off, the process proceeds to step S3.
At 03, the pressure of the wheel cylinder W / C of the FR-RL system is stored in P10, and the pressure of the FL-RR system is stored in P20.

Thereafter, SOL3 on the pressure increasing side of the sub hydraulic system
The SOL 7 is turned on for a predetermined time (for example, 50 ms) in a category that does not affect the brake control (a state where the brake is not dragged at the time of starting), and the brake pressure applied to the wheel cylinder W / C is artificially increased. . Then, the W / C pressure after the pressure increase is detected again, the pressure of the FR-RL system after the pressure increase is stored in P11, and the FL-
The pressure of the RR system is stored in P21.

Thereafter, in the FR-RL system, pressure changes P11-P10 before and after pressure increase are compared with a predetermined value Pj1 (for example, 5 kgf · cm ² ), and P11-P10 is determined as P11-P10.
If it is larger than j1, it is considered that the pressure change due to pressure increase is normal, and the FR-RL abnormal flag is turned off.
If the pressure change due to the pressure increase is equal to or less than Pj1, it is considered that the pressure change is abnormal, and the FR-RL abnormality flag is turned on.

Similarly, in the FL-RR system, the pressure changes P21-P20 before and after pressure increase are set to a predetermined value Pj.
2 (for example, 5 kgf · cm ² ) and P11-P
If 10 is greater than Pj2, it is considered that the pressure change due to pressure increase is normal and the FL-RR system abnormality flag is turned off. If the pressure change due to pressure increase is equal to or less than Pj2,
The pressure change is regarded as abnormal, and the FL-RR system abnormality flag is turned on. Then, the sub hydraulic system failure determination end flag is turned on, and this processing ends.

Here, SOL3 and SOL7 are used for the failure of the SOL1 and SOL5 on the pressure increasing side, and the SOL on the pressure decreasing side is used.
The case where the SOLs 4 and 8 are used for failures 2 and 6 has been described. However, it is not limited to a valve at the time of failure or an emergency valve for preventing collision with an obstacle. These SOLs 3, 4, 7, and 8 are SO
It can also function as a valve that assists the pressures L1, 2, 5, and 6 to rapidly increase and decrease the pressure.

Further, when the SOLs 3, 4, 7, and 8 are not used in normal brake control or are used infrequently, or are valves used when a hydraulic system for performing normal brake operation fails. Even if there is, the abnormality can be detected in an appropriate state when the vehicle is stopped by the failure determination shown in FIG.

[0046]

According to the first aspect of the present invention, one of the pressure-intensifying valves is operated for a predetermined time each time the vehicle stops, and the abnormality of the hydraulic system is detected by a change in hydraulic pressure before and after the operation. In a device with a dual hydraulic configuration, a valve that assists normal brake control, a valve that is not used or is used less frequently in normal brake control, or a normal brake operation is used. The abnormality determination can be performed in an appropriate state even when the hydraulic system to be performed includes a valve used when a failure occurs.

According to the second invention, the emergency valve used in the event of a failure is activated each time the vehicle is stopped, and the abnormality in the hydraulic system is detected based on a change in hydraulic pressure before and after activation.
Abnormality detection is performed every time the vehicle stops, and abnormality detection can be performed periodically. Therefore, a valve that assists normal brake control in a device that has a dual hydraulic configuration, used in normal brake control The abnormality determination can be performed in an appropriate state even when a valve that is not used or that is used infrequently, or a valve that is used when a hydraulic system that performs a normal brake operation fails, is provided.

[Brief description of the drawings]

FIG. 1 is a hydraulic configuration diagram of a brake control device according to an embodiment of the present invention.

FIG. 2 is an external connection diagram of a controller of the brake control device according to the embodiment of the present invention.

FIG. 3 is a main flowchart showing processing of a controller shown in FIG. 2;

FIG. 4 is a flowchart of the automatic brake control shown in FIG.

FIG. 5 is a flowchart of a sub hydraulic system failure determination shown in FIG. 4;

[Explanation of symbols]

3 Controller 100 Brake control device ACC1, ACC2 (accumulator (pressure supply source)) W / C Wheel cylinder (brake device) SOL1, 5 Booster solenoid (hydraulic control valve on booster side) SOL2, 6 Depressor solenoid (hydraulic control valve on depressurizer side) SOL3,7 Pressure increase solenoid at failure (pressure increase side emergency hydraulic pressure control valve) SOL4,8 Pressure decrease solenoid at pressure failure (pressure reduction side emergency hydraulic control valve)

Continued on front page F-term (reference)

Claims (2)

[Claims] 1. A brake control device for automatically controlling a hydraulic pressure supplied from a pressure supply source to a wheel brake device, comprising: a pair of hydraulic control valves for controlling the hydraulic pressure; One of them is operated to increase pressure for a predetermined time,
A brake control device for detecting an abnormality in a hydraulic system based on a change in hydraulic pressure before and after a brake is applied. 2. The vehicle according to claim 1, wherein the pair of hydraulic control valves include a normal hydraulic control valve that is operated during normal brake operation and an emergency hydraulic control valve that operates an emergency brake when the normal hydraulic control valve fails. 2. The brake control device according to claim 1, wherein the emergency hydraulic pressure control valve is operated to increase the pressure every time and an abnormality in the hydraulic system is detected based on a change in hydraulic pressure before and after the brake operation.