KR20100116782A

KR20100116782A - Method for diagnosing fault in electric brake system

Info

Publication number: KR20100116782A
Application number: KR1020090035370A
Authority: KR
Inventors: 손홍엽
Original assignee: 주식회사 만도
Priority date: 2009-04-23
Filing date: 2009-04-23
Publication date: 2010-11-02

Abstract

PURPOSE: A method for diagnosing mechanical troubles of an electronic parking brake is provided to rapidly and accurately diagnose multiple switches and battery power required for operating a parking brake. CONSTITUTION: A method for diagnosing mechanical troubles of an electronic parking brake is as follows. Battery power for supplying power to an electronic parking brake and a switch for controlling the operation of the parking brake are simultaneously diagnosed. The simultaneous diagnoses are performed when a car is turned on or off(50,54). Residual switches are additionally diagnosed.

Description

Method for diagnosing faults in electric parking brakes

The present invention relates to a method for diagnosing a failure of an electronic parking brake, and more particularly, to a method for diagnosing a failure of an electronic parking brake for diagnosing a failure of each part for controlling the operation of the electronic parking brake.

In general, an electric parking brake (hereinafter referred to as EPB) that electronically controls the driving of the parking brake has been developed and used.

The electronic parking brake (EPB) controls the braking force applied to the wheels automatically to prevent the vehicle from being pushed back when the vehicle stops or when the hill leaves, even if the driver does not manually activate the parking brake. Maintain state.

A vehicle employing such an electronic parking brake (EPB) has an activation switch (hereinafter referred to as AS) for activating the electronic parking brake and a release switch (hereinafter referred to as RS) for inactive state. do. If you want to operate the electronic parking brake, such as to keep the vehicle stable by preventing the vehicle from slipping on the slope without the manual operation of the driver, the operation switch (AS) is turned on by the driver. In order to cancel the operation of the parking brake automatically made by the EPB, the release switch RS is turned on by the driver. Therefore, since the reliability of the electronic parking brake can be ensured when the operation switch and the release switch are normally operated, it is necessary to diagnose the failure of these switches.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a method for diagnosing a failure of an electronic parking brake for accurately and quickly diagnosing a failure of each part related to the operation of the electronic parking brake.

According to the present invention, there is provided a method for diagnosing a failure of an electronic parking brake, comprising: concurrently diagnosing a battery power supplying power to an electronic parking brake and any one switch for controlling the operation of the electronic parking brake; And additionally diagnosing the remaining switches excluded from the failure diagnosis.

The simultaneous fault diagnosis is performed at start-up or start-off timing.

The fault diagnosis switch includes an operation switch for activating the electronic parking brake or a release switch for releasing an active state, and simultaneously diagnoses any one of the operation switch and the release switch and the battery power.

As described above, the present invention simultaneously diagnoses any one switch for controlling the operation of the battery power and the electronic parking brake, so that the diagnosis of the battery power and the multiple switches for operating the electronic parking brake can be performed quickly and accurately.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail.

As shown in FIG. 1, the electronic parking brake employed in the vehicle includes a switch unit 10, an electronic control unit (ECU) 20, and a display unit 30.

The switch unit 10 includes an operation switch AS and a second driving power source VCC2 for providing one of the first driving power source VCC1 and the battery power source BAT to the control unit 21 of the control unit 20. And a release switch RS for providing any one of the battery power BAT to the control unit 21 of the control unit 20. The operation of release switch RS and actuation switch AS is controlled by the driver.

The electronic control unit 20 includes first to third test switches SW1 (SW2) SW3 and a control unit 21. The operation of each of the inspection switches SW1, SW2 and SW3 is controlled by the controller 21.

The electronic control unit 20 includes a control unit 21 for checking the operation state of the operation switch AS and the release switch RS and the supply state of the battery power source BAT using a preset test pattern. In order to shorten the test time for the operation switch and the battery power, the controller 21 simultaneously checks the release switch RS and the battery power BAT, and then checks the operation state of the operation switch AS. This test method is intended to solve the time-consuming process of checking each switch and battery power one by one.

The failure switch diagnosis method of the electronic parking brake according to the present invention will be described.

As shown in FIG. 2, the test signal SD is turned on when the engine is turned on. Immediately after the inspection signal SD is turned on, the controller 21 controls the operation switch AS and the release switch RS according to the voltages at the third to sixth inspection points P3, P4, P5 and P6. Check it. Here, the voltages of the third to sixth inspection points P3, P4, P5, and P6 may be preset in advance as shown in FIG. 3 when the operation switch AS or the release switch RS is not activated by the driver. It is indicated by the set voltage Va. Therefore, when the voltage change is different from the set voltage Va at the third and fourth points P3 and P4, the controller 21 recognizes a state in which the failure occurs in the operation switch AS. Similarly, if a voltage change occurs differently from the set voltage Vb at the fifth and sixth points P5 and P6, the controller 1 recognizes a failure in the release switch RS. When the failure of the switch is recognized, the display unit 30 displays the cause of the failure.

When the first test time T0 elapses from the time when the start-up is turned on, the test signal SD is changed from ON to OFF. At this time, the control unit 21 simultaneously turns on the third test switch SW3 and the release switch RS for the second test time T1 and releases the third test switch SW3 and the release using a preset test pattern. Check the switch (RS). At this time, the operation switch (AS) is turned off (OFF) (50, 51).

As shown in FIG. 3, when it is determined that the voltage of the second test point P2 reaches the battery voltage Vb in the ON state of the third test switch SW3, the battery power is in a normal state. It is admitted. In addition, the voltages at the fifth test point P5 and the sixth test point P6 are similarly changed according to the test pattern output from the controller 21 when the release switch RS is OFF. When the release switch RS is turned on, the voltages of the fifth inspection point P5 and the sixth inspection point P6 are different from each other. Therefore, the voltage change is viewed to diagnose whether the release switch RS has failed. That is, when the voltage input through the release switch RS is the battery voltage Vb during the first test time T1, the release switch RS is recognized as being in a normal state.

The failure diagnosis of the operation switch AS is performed by turning off the third inspection switch SW3 and the release switch RS during the third inspection time T2, similarly to the failure diagnosis of the release switch RS. Since the voltages of the third test point P3 and the fourth test point P4 should be different from each other when the switch AS is turned on, the voltage change is viewed to diagnose whether the operation switch AS is broken. (52).

The control unit 21 displays the diagnosis result for the operation switch AS, the release switch RS, and the battery power source BAT on the display unit 30. Accordingly, the driver can check the diagnosis result (53).

On the other hand, as shown in Figure 4, when the start-off (OFF) it is diagnosed whether the battery power (BAT) and the release switch (RS) failure (54, 55). That is, the third test switch SW3 and the release switch RS are turned on at the same time, and then according to the voltage change of the second test point P2 and the fifth and sixth test points P5 and P6. Diagnose the failure. The failure diagnosis result is stored in the internal memory by the controller 21 (56). The stored diagnostic information is intended to be taken by the driver.

1 is a circuit diagram of an electronic parking brake to which the present invention is applied.

2 is a view for explaining the operation of checking each switch and the battery power when the power-on (ON) in accordance with the present invention.

3 is a diagram illustrating signals of respective units in the case of simultaneously checking the battery power and the release switch according to the present invention.

4 is a view showing an operation of simultaneously checking the battery power and the release switch when the start-off (OFF) in accordance with the present invention.

5 is a flowchart illustrating a failure switch diagnosis method of an electronic parking brake according to the present invention.

* Description of the symbols for the main parts of the drawings *

10: switch unit

20: Electronic parking brake control unit (EPB ECU)

21: control unit

30: display unit

Claims

Concurrently diagnosing a battery power supplying power to the electronic parking brake and any one switch that controls operation of the electronic parking brake;

And additionally diagnosing faults for the remaining switches excluded from the fault diagnosis.

The method of claim 1,

The simultaneous failure diagnosis method for diagnosing a failure of the electronic parking brake is performed at the start-on or start-off time.

The method of claim 1,

The fault diagnosis switch includes an operation switch for activating the electronic parking brake or a release switch for releasing an active state, and fault diagnosis of the electronic parking brake for simultaneously diagnosing any one of the operation switch and the release switch and the battery power. Way.