JPH05178195A - Anti-skid controller - Google Patents

Abstract

PURPOSE:To prevent erroneous operation of an anti-skid controller caused by a brake switch, the abnormality of which is detected during normal running, without generating instability of a vehicle. CONSTITUTION:An anti-skid controller is composed of a means for detecting whether a brake switch is turned ON until a running car body is stopped (step 10), a means for detecting deceleration when the running car body is stopped (step 13), and a means for determining abnormality of a brake switch when the brake switch is never turned ON though the car is stopped at the deceleration of not less than a predetermined value KG (when a flag F1=1), (steps 14-15).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-skid control device that operates when a vehicle is braked, and more particularly to an anti-skid control device that can easily detect the presence or absence of a brake switch failure.

[0002]

2. Description of the Related Art Generally, when a vehicle is braked, the descending slope of the vehicle speed does not match the descending curve of the wheel speed,
Depending on the braking conditions at that time, the wheel speed drops significantly, the deceleration increases, and the wheels eventually lock. Therefore, when a drop in wheel speed above a certain reference value is detected after applying the brake, the anti-skid control device operates to gradually reduce the brake hydraulic pressure applied to the wheel in order to prevent the wheel from locking. To go. When the wheel speed returns due to the pressure reduction, the brake hydraulic pressure is temporarily held at that time, then the hydraulic pressure is linearly increased, and then the pressure is increased stepwise (pulse increase).

As a result, when a drop in the wheel speed exceeding a certain reference value is detected again, the brake hydraulic pressure applied to the wheel is gradually reduced again, and when the wheel speed returns again, the brake hydraulic pressure is again reduced. Holding, boosting,
Increase the pulse pressure. By repeating such a process, the wheel speed is lowered along a certain target value (for example, about 80% of the vehicle body speed at that time), and the predetermined braking distance is prevented while preventing the locked state. Then, the vehicle is stopped.

By the way, in such an anti-skid control device, even when the signal from the brake switch for detecting the brake operation by the driver is off, when the slip ratio of the wheels becomes larger than a predetermined slip ratio. Indicates that the brake switch has failed (for example, disconnection failure)
If such a determination is made, the anti-skid control is started at the above-mentioned large slip ratio (that is, a slip ratio deeper than the normal time when the brake switch is normally operating). It is thought to do.

However, when the above-described brake control is performed, the start sensitivity of the anti-skid control when the brake switch is determined to be defective is deep, so that the wheel speed is greatly reduced and the vehicle becomes unstable. There was a problem that there is a possibility that it will be in a different state.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and does not cause the unstable vehicle condition due to the brake control with the deep slip ratio as described above, and allows the vehicle to run normally. By detecting the presence or absence of a failure of the brake switch at a time (that is, a state in which normal starting and stopping are repeated), the atchi skid control based on the failure of the brake switch without causing a sense of instability of the vehicle. This is to prevent malfunction of the device.

[0007]

According to one embodiment of the present invention, in order to solve such a problem, a means for detecting whether or not a brake switch is turned on before the traveling vehicle body stops, A means for detecting the vehicle body deceleration at the time of stopping, and a case where the detected vehicle body deceleration is equal to or more than a predetermined value and the ON state of the brake switch is never detected, the brake switch is abnormal. An anti-skid control device is provided which is provided with means for determining.

According to another aspect of the present invention, means for detecting whether or not the brake switch is turned on before the traveling vehicle body stops, and means for detecting the number of times the traveling vehicle body has repeatedly started and stopped. And an anti-skid control device provided with means for determining that the brake switch is abnormal when the ON state of the brake switch is not detected even once while the start / stop is repeated a predetermined number of times. To be done.

[0009]

According to the above structure, since the abnormality of the brake switch can be determined during the normal running of the vehicle, even when the brake switch is out of order, the control start sensitivity is normal (that is, the drop in the wheel speed is not so large). The anti-skid control can be performed, and thus the malfunction of the device due to the failure of the brake switch can be prevented without causing the instability of the vehicle.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, FIGS. 5 and 6 are flowcharts showing the general operating procedure of an anti-skid control device. That is, at the beginning of control, step 11 becomes a no and step 12 becomes yes. As a result, when the control is started, the pressure reducing mode is set in step 13. Next, if the control is not ended in step 14, the process proceeds to step 15 and the mode is determined. (It is determined by the normal flag, and the pressure reducing mode is set in this case.) If step 12 does not start and the control is not started and step 14 is YES, the control proceeds to step 28 and the non-operation is completed. It becomes control.

As described above, when it is determined in step 15 that the pressure reducing mode is selected, the process proceeds to step 16, and until the pressure reducing mode is completed, the process proceeds to step 24 to perform pressure reducing output,
The brake hydraulic pressure is gradually reduced. And step 16
When the depressurization mode ends, the holding mode is set in step 17 and the process proceeds to step 18, and until the holding mode ends, the process proceeds to step 25, where the holding output is made and the brake held at a predetermined value. Hydraulic pressure is output. At this time, step 11 is YES because the control is being performed, and if the control is not ended in step 14, the mode determination in step 15 is the holding mode.

When the holding mode is completed in step 18, the pressure increasing mode is set in step 19 and the process proceeds to step 20. In step 26, the pressure increasing output is performed until the pressure increasing mode is completed. , The brake hydraulic pressure is linearly increased. At this time as well, step 11 is under control, so the answer is yes. If the control is not ended in step 14, the mode determination in step 15 is the pressure increasing mode.

When the pressure boosting mode is completed in step 20, the pulse pressure boosting mode is set in step 21 and the process proceeds to step 22. Until the pulse pressure boosting mode is completed, the process proceeds to step 27 and pulse boosting is performed. A pressure output is made and the brake oil pressure is increased stepwise. At this time as well, step 11 is under control, so yes. If step 14 does not end the control, step 1
The mode determination of 5 is the pulse pressure increasing mode.

When the pulse pressure increasing mode is completed in step 22, the pressure reducing mode is set again in step 23, and the process proceeds to step 24 to perform pressure reducing output.
At this time as well, step 11 is under control, so the answer is yes, and if the control is not ended in step 14, the mode determination in step 15 is the decompression mode, and thereafter, until the control is ended in step 14, The modes of depressurization → holding → boosting → pulse boosting → depressurization → ……… are set repeatedly in sequence. In this case, the time for which each of the above modes (for example, the pressure reducing mode) is set is determined according to the state of the speed of the wheel.

FIG. 4 is a system configuration diagram of an anti-skid control device of this type, in which the brake oil filled in the master cylinder M / C by depressing the brake pedal is applied to each wheel (each wheel on the left and right front wheels). F respectively
Shown by L and FR, the left and right rear wheels are respectively RL and R
Indicated by R. ) Is supplied to a wheel cylinder W / C provided so as to face each wheel, and the above wheels are braked. In this case, the actuators corresponding to the respective wheels controlled by the ECU (that is, FL.ACT; FR.A.
CT; RL. ACT; and RR. The brake hydraulic pressure applied to each wheel is changed by (ACT). Sensor signals from the wheel speed sensors WS1 to WS4 for the respective wheels are input to the ECU. The output side of the master cylinder is divided into a side C1 for supplying hydraulic pressure to the pair of wheels FR and RL and a side C2 for supplying hydraulic pressure to the remaining pair of wheels FL and RR. Even if a failure occurs in the hydraulic system, the brakes are secured in the remaining hydraulic system.

FIG. 3 shows the ECU of FIG.
1 shows an example of a configuration applied to the present invention, in which the ECU
Signals from various switches (for example, the above-mentioned brake switch for confirming that the brake pedal is depressed) are input to the CPU 11 provided therein via the level conversion circuit 12, and the wheel speed sensors WS1 to WS1 for the respective wheels are provided. W
The sensor signal from S4 is a waveform shaping (pulse shaping) circuit 1
3 to 16 and further from the battery B to the C
The power supply circuit 17 for PU is input.

A motor relay MR is connected to the output side of the CPU 11 through a motor relay drive circuit 21, and when the relay MR is turned on, the pump motor (oil accumulated in the reservoir during depressurization is transferred to the master cylinder M / C). The motor for returning) PM is activated. When an abnormality (for example, a failure) occurs, the abnormality driving lamp L is operated through the lamp drive circuit 22. If there is no abnormality in the ECU, the solenoid relay SR is always turned on through the solenoid relay drive circuit 27. If the solenoid relay SR is turned on, the actuator corresponding to each wheel (that is, F
R. ACT; FL. ACT; RR. ACT; and R
L. ACT) is controlled by the CPU 11.

In such an anti-skid control device,
As described above, the present invention has means for detecting whether or not the brake switch is turned on before the traveling vehicle body stops, and the brake is applied even when the traveling vehicle body stops at a deceleration of a predetermined value or more. If the switch has never been turned on, or if the number of times the vehicle has started / stopped has exceeded the specified number of times and the brake switch has not been turned on during that time, it is determined that the brake switch is abnormal. It was done.

FIG. 1 is a flow chart showing an embodiment of the processing procedure of the anti-skid control device according to the present invention. It starts at step 1 and at step 2, the judgment flag (checking flag) F ₁ is "1". Is determined. If the result is NO, the routine proceeds to step 3, where the vehicle speed Vs at that time (this is the sensor signal having the maximum value among the sensor signals from the wheel speed sensors WS1 to WS4 shown in FIG. 3, that is, not locked). (Which can be detected from the wheel speed signals from the wheels) is equal to or higher than a predetermined start determination start vehicle speed KV. If the determination is yes, it is determined that the vehicle has started (started) once, and in step 4, the determination flag F ₁ is set to "1". When the flag F ₁ is set to "1", the determination at the above step 2 becomes YES at the next calculation timing and the routine proceeds to step 5, where the vehicle body speed V _{s (n)} at the current calculation timing is the last time. It is determined whether the vehicle speed is higher than the vehicle speed V _{s (n-1)} at the calculation timing of, and if yes, the process proceeds to step 6 and the vehicle speed V _{s (n)} is updated and stored in the memory. It In this way, the maximum value of the vehicle body speed is always stored and held in the memory, at which time the count value of the timer is reset to 0 in step 7.

Next, at step 8, it is judged whether the vehicle body speed Vs has become 0 (that is, a stop judgment).
Then, while the determination is "NO" (that is, before Vs = 0), the count value of the timer is incremented in step 9 and it is determined in step 10 whether the brake switch is turned on. If yes (when the brake switch is turned on), the count value of the timer is reset to 0 in step 11 and the flag F ₁ is also set to "0" in step 12, but no If (ie if the brake switch is not turned on)
The procedure is repeated as is, and the route from step 2 to step 5 is repeated. In this way, when the vehicle body is stopped (that is, when the vehicle body is stopped without the brake switch being turned on), the determination in step 8 is YES, so the process proceeds to step 13, and at that time, The vehicle body deceleration at that time is calculated by dividing the vehicle body speed stored and held in the memory by the count value of the timer. Then, it is determined in Step 1 that the calculated vehicle deceleration is equal to or higher than the predetermined determination deceleration KG.
4 (that is, the brake switch has never been turned on even though the traveling vehicle body has stopped at the deceleration of the predetermined value KG or more), the routine proceeds to step 15 and the brake switch is abnormal. Flag is set.
In this way, when the brake is stopped at a deceleration of a predetermined value or more, although it is considered that the brake is stepped on, if the brake switch is never turned on, the brake switch is turned on. If there is an abnormality, the failure is detected.

FIG. 2 is a flow chart showing another embodiment of the processing procedure of the anti-skid control device according to the present invention. It is determined in step 1 whether or not the vehicle body is stopped. , If the vehicle speed is Vs, then it is determined in step 3 whether or not the vehicle speed Vs at that time is higher than the predetermined vehicle speed KV for start determination. If YES (that is, if it is determined that the vehicle has started), "1" is set in the checking flag F ₁ in step 4. Then, while the vehicle body speed is equal to or lower than the predetermined speed KV and the vehicle body is not stopped, the routine proceeds from step 3 to step 5 in which the checking flag F ₁ is already set to "1". It is determined whether or not there is. If yes, the process proceeds to step 6 and it is determined whether the brake switch is turned on. If YES (when the brake switch is turned on), the flag F ₁ is set to "0" in step 7 and the count value of the start / stop counter CT is reset to 0 in step 8 If (i.e., the brake switch is not turned on), the routine directly returns, and the route from step 3 to step 5 is repeated until the vehicle body stops.

When the vehicle body is stopped in this way, the process proceeds from step 2 to step 9 and the flag F ₁ is set to "1".
Is determined (that is, whether the brake switch has not been turned on during the stop after the start determined in step 3 above), and if yes, the start is performed in step 10.・ Stop counter CT
The count value of is counted up. Next, at step 11, the count value of the start / stop count CT (that is, the number of times of the start / stop) is a predetermined number KN (for example, 10).
It is determined whether or not the number is equal to or more than the number of times. If the result is NO, the flag F ₁ is once set to "0" in step 12, but if the result is YES (that is, the number of times of starting / stopping has reached a predetermined number KN, the above-mentioned brake is applied during that time). If the switch has never been turned on), the abnormality flag of the brake switch is set in step 13. Note that, here, as the number of times of starting / stopping KN serving as a reference for determining the abnormality of the brake switch, considering that the traveling vehicle body may be stopped only by engine braking (slowly decelerating and stopping). Thus, a predetermined number of times (for example, 10 times) is set.

[0023]

According to the present invention, since the abnormality of the brake switch can be detected during the normal running of the vehicle body, it is not necessary to deepen the control start sensitivity even when the brake switch is abnormal (that is, the wheel speed is reduced). Since the anti-skid control can be performed with the normal control start sensitivity without increasing so much, the malfunction of the anti-skid control device based on the abnormality of the brake switch can be caused without causing the instability of the vehicle. Can be prevented.

[Brief description of drawings]

FIG. 1 is a flowchart showing one embodiment of a processing procedure of an anti-skid control device according to the present invention.

FIG. 2 is a flowchart showing another embodiment of the processing procedure of the anti-skid control device according to the present invention.

FIG. 3 is a diagram showing an example of a configuration applied to the present invention as the ECU shown in FIG. 4.

FIG. 4 is a diagram illustrating a system configuration of an anti-skid control device.

FIG. 5 is a flowchart illustrating a general processing procedure of the anti-skid control device.

FIG. 6 is a flowchart illustrating a general processing procedure of the anti-skid control device.

[Explanation of symbols]

WS1 to WS4 ... Wheel speed sensor M / C ... Master cylinder W / C ... Wheel cylinder FR, FL, RR, RL ... Front wheel and rear wheel FR. ACT; FL. ACT; RR. ACT; RL. A
CT; ... Actuator corresponding to each wheel

Claims (2)

[Claims] 1. A means for detecting whether or not a brake switch is turned on before the traveling vehicle body stops, a means for detecting a vehicle body deceleration when the traveling vehicle body stops, and the detected vehicle body deceleration. Is greater than or equal to a predetermined value and the ON state of the brake switch is never detected, the anti-skid control device further comprises means for determining that the brake switch is abnormal. 2. A means for detecting whether or not a brake switch has been turned on before the traveling vehicle stops, a means for detecting the number of times the traveling vehicle has repeatedly started and stopped, and a predetermined number of times for starting and stopping the vehicle. An anti-skid control device comprising means for determining that the brake switch is abnormal when the ON state of the brake switch is not detected during the repeated operation.