KR20150125162A - Electronic parking brake system in a vehicle and method thereof - Google Patents

Abstract

The present invention is provided to control a vehicle by detecting malfunction caused by a short circuit in an electronic parking brake system so that an accurate electric current can be transmitted to the motors of both wheels according to the operation commands of an MCU in the electronic parking brake system. Provided is a parking brake system comprising: a first motor; a first motor drive circuit for blocking or supplying power which is supplied to the first motor; a second motor; a second motor drive circuit for blocking or supplying power which is supplied to the second motor; a short-circuit detecting part for detecting a short circuit between the first motor drive circuit and the second motor drive circuit; an MCU for determining a short circuit between the first motor drive circuit and the second motor drive circuit depending on output from the short-circuit detecting part; and a display part for warning a user of a short circuit between the first motor drive circuit and the second motor drive circuit.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic parking brake system for a vehicle,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic parking brake system for a vehicle and a control method thereof, and more particularly to a circuit for detecting a fault on a circuit, which may occur in a motor driving circuit in an electronic parking brake system of a vehicle, Invention.

Generally, the brake device has a parking brake such as a normal hand brake or a side brake which keeps the vehicle stationary. The parking brake is operated when the driver operates the parking lever provided on the driver's seat inside the vehicle. When the driver pulls the parking lever and pulls the cable connected to it, the rear wheel brake assembly connected to the cable is operated to secure the braking force. On the contrary, if the cable lever is released, the braking force is released.

However, since the operation of the parking brake according to the operation of the parking lever is operated only by the will of the driver, when the vehicle is parked on a ramp or the like without pulling the parking lever inadvertently, the vehicle rolls down and causes an unexpected accident . In addition, since the driver has to operate the parking lever at the time of parking or each time the operation is started, the use of the parking lever is very troublesome.

Accordingly, in recent years, an electronic parking brake (EPB) system for electronically controlling the driving of the parking brake has been used, and is mounted on a normal disk brake to perform a parking brake function.

The electronic parking brake system allows the parking brake to be automatically operated or released in accordance with a simple switch operation or control judgment of the electronic control unit managing the entire control even if the driver does not operate the parking brake manually.

The electronic parking brake system includes an actuator having a motor for generating a braking force and an electronic control unit (ECU) for driving the actuator. The ECU consists of an MCU, several sensor interfaces, a motor drive and a communication module. The electronic control unit ECU drives the actuator according to the operation state of the switch to apply or release the electronic parking brake system. However, there has been a problem in the circuit diagram of the rear wheel left motor and the rear wheel right motor of the circuit in the electronic control unit (ECU) due to disconnection.

Embodiments of the present invention seek to control the vehicle so that the correct current is delivered to the motors of both wheels according to the operating instructions of the MCU in the vehicle's electronic parking brake system by detecting faults due to a short circuit across the motor.

Further, in order to solve the above-mentioned problem, a user is warned when a short circuit between the ends of the motor is detected.

According to an aspect of the present invention, there is provided a motor control apparatus comprising: a first motor; a first motor drive circuit for interrupting or supplying power to the first motor; A second motor drive circuit for driving the first motor drive circuit and the second motor drive circuit; a short detection part for detecting a short circuit between the first motor drive circuit and the second motor drive circuit; An electronic parking brake system including an MCU for judging a short circuit between the first motor drive circuit and the second motor drive circuit and a display unit for warning the user of a short circuit between the first motor drive circuit and the second motor drive circuit.

Further, when the power supplied to the first motor and the second motor of the vehicle is cut off, the MCU can judge a short circuit between the first motor drive circuit and the second motor drive circuit.

The short detection portion may include a first short detection circuit connected to the first motor drive and a second short detection circuit connected to the second motor drive.

The MCU may apply a first voltage to the first short detection circuit and determine a short circuit between the first motor drive circuit and the second motor drive circuit in accordance with the output of the second short detection circuit .

When the first short-circuit detection circuit outputs a first voltage, if the output value of the second short-circuit detection circuit is not 0 [V], the first motor drive circuit and the second motor drive circuit are short- .

The MCU may also apply a second voltage to the second short detection circuit and determine a short circuit between the first motor drive circuit and the second motor drive circuit in accordance with the output of the first short detection circuit .

When the second voltage is applied to the second short-circuit detection circuit, if the output value of the first short-circuit detection circuit is not 0 [V], the MCU controls the first motor drive circuit

It can be determined that the second motor drive circuit is short-circuited.

Embodiments of the present invention can detect when an MCU signal is undesirably misdirected to the right motor and the left motor by configuring a circuit diagram for detecting a short circuit within the electronic parking brake system.

Further, by configuring a circuit diagram for detecting an error in the electronic parking brake system caused by a short circuit in the ECU, the user can be warned when an error occurs.

1 is a cross-sectional view of a brake that may be used in an embodiment of the present invention.
2 is a block diagram of an electronic parking brake system according to the present invention.
3 is a short circuit detection circuit diagram of a single motor.
Figure 4 is a schematic diagram of a short circuit detection circuit that has experienced an inter-motor short circuit.
5 is a graph of the voltage change of the motor over time during normal operation.
6 is a graph of the voltage change of the motor over time when a short circuit occurs between the motors.
7 is a flowchart for explaining a control method of the electronic parking brake system according to the present invention.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory only and are not restrictive of the invention, as claimed, and it is to be understood that the invention is not limited to the disclosed embodiments.

Hereinafter, a vehicle according to an embodiment will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of a brake that may be used in an embodiment of the present invention.

The brake main body is provided with a cylinder 62 to which hydraulic pressure generated in the master cylinder is supplied, a caliper housing to which a pad plate having brake pads 63 and 67 attached thereto is fixed, and a cylinder which is linearly movably inserted into the cylinder A piston 65 which is linearly moved by hydraulic pressure, a pad plate which is attached to an end portion of the piston and to which the brake pads 63 and 67 are attached, and a brake which is disposed between the two brake pads 63 and 67, Disk 68 as shown in FIG.

The brake piston 65 moves along the axis of rotation of the motor to transmit the movement force to the brake pad 67. [

A connection link of the electronic parking brake of the motor may be installed inside the brake piston 65. [

When the motor 61 of the electronic parking brake rotates, the brake piston 65 translates in a direction parallel to the rotation axis of the motor. The brake piston 65 moves toward the brake pad 67 and comes into contact with the brake pad 67 and causes the brake pad 67 to press the brake disc 68. [

When the brake pad 67 is pressed against the brake disk 68 by the brake piston 65 in the same direction as the brake piston 65 of the pair of brake pads 63 and 67 and the brake disk 68 is pressed against the brake disk 68, (65). At this time, the brake pad 63 on the opposite side also presses the brake disc 68.

As a result, the pair of brake pads 63 and 67 press the brake disc 68 in both directions to generate a braking force due to the frictional force between the brake pads 63 and 67 and the brake disc 68.

The MCU and the left and right motor drives that control the operation of the motor-on-caliper type brake of Fig. 1 will be described later.

FIG. 2 is a block diagram of an electronic parking brake system according to the present invention, and FIG. 3 is a voltage application circuit diagram of a single motor as a detailed configuration of an electronic parking brake according to an embodiment of the present invention. 4 is a schematic diagram of a circuit diagram when a short circuit occurs between the motors. In an embodiment of the present invention, an electronic parking brake system of a motor on caliper type will be described as an example.

According to an embodiment of the present invention, an electronic parking brake system includes an MCU 100, a display unit 400, a rear right motor drive 200, a rear left motor drive 300, a right motor a, ), And a short-circuit detection unit (23).

The MCU 100 can totally control the electronic parking brake system.

The MCU 100 controls the ON and OFF of the application SW and the release SW included in the right motor drive 200 and the left motor drive 300 and controls ON / OFF of the voltage application switch to the left and right motors And controls the display unit 400 to control the warning signal.

The MCU 100 can independently control the right motor drive 200 and the left motor drive 300 when driving the electronic parking brake of the left and right rear wheels.

When receiving the operation signal from the MCU 100, the right motor drive 200 turns on the application SW or the release SW to supply power from the first battery BAT1 to the motor.

When the left motor drive 300 receives the operation signal from the MCU 100, the left motor drive 300 turns on the application switch and the release switch to supply power from the second battery BAT2 to the motor.

The short detection portion 23 includes a first short detection circuit 21 and a second short detection circuit 22.

The first short detection circuit 21 is a short detection circuit connected to the right motor drive, detects a short circuit and transmits the detection result to the MCU.

The microcomputer 100 receives a voltage application signal and the first short detection circuit 21 turns on the voltage application switch to detect whether a short circuit has occurred in the electronic parking brake system.

The second short detection circuit 22 is a short detection circuit connected to the left motor drive, detects a short circuit and transmits the detection result to the MCU.

The microcomputer 100 receives a voltage application signal and the second short detection circuit 22 turns on the voltage application switch to detect whether a short circuit has occurred in the electronic parking brake system.

The display unit 400 can warn the user that the measured voltage value at the right motor monitoring point and the left motor monitoring point is different from the expected voltage value and is determined as a malfunction.

The display unit 400 can give a visual warning to the user through the display. However, the present invention is not limited to this, and for example, the acoustic unit may give an acoustic warning to the user.

The application SW and the release SW are not both turned on by the MCU 100 and the disconnection detection operation in the electronic brake system of the present invention in a state where both the application SW and the release SW are both off will be described later in Fig. .

 When the application SW or the release SW is operated, the release SW is turned on when the application SW is turned off and the release SW is turned off when the application SW is turned on. In this case, the magnitude of the voltage that can be measured at the motor monitoring point maximizes the voltage value (Vdd) applied to the motor.

Therefore, it is possible to detect a malfunction due to disconnection of the circuit when both the application SW and the release SW are turned off.

When the application switch and the release switch are all turned off by the MCU 100, the voltage of the motor can be measured at the motor monitoring point 33 by turning on / off the applied voltage switch SW.

When the applied voltage switch SW is turned off, the voltage measured at the motor monitoring point 33 is 0 [V] because it is grounded to the ground.

When the applied voltage switch SW is turned on, the voltage value measured at the motor monitoring point 33 is measured as a voltage value corresponding to the voltage division of the applied voltage Vdd.

In one embodiment, the voltage value measured at the motor monitoring point is equal to Vdd / 2 [V] when the motor 31 has an impedance 31 of the same magnitude above and below the motor monitoring point 33 as shown in FIG.

4 is a schematic diagram of a circuit diagram in which a short circuit occurs between drive motors.

4 includes a left motor circuit and a right motor circuit which are independently controlled by one MCU 100. [

The first short detection circuit includes a first applied voltage switch SW1 and a first motor monitoring point (node 1) 41, to which the voltage value Vdd1 [v] is applied with the first applied voltage switch SW1 turned on . In the second short detection circuit, the voltage value Vdd2 [v] is applied to the second application voltage switch SW2, and the second application voltage switch SW2 and the second motor monitoring point (node 2) .

The first applied voltage switch (SW1) and the second applied voltage switch (SW2) operate in reverse by the MCU (100). For example, when the first applied voltage switch SW1 is turned on, the second applied voltage switch SW2 is turned off. When the first applied voltage switch SW1 is turned off, the second applied voltage switch SW2 is turned on.

Since the left motor circuit and the right motor circuit are independently controlled by the MCU 100, when the normal operation is performed, the motor application voltage Vdd1 [v] of the left motor circuit is short-circuited to the right motor circuit It does not affect. In addition, during normal operation, the motor applied voltage Vdd2 [v] of the right motor circuit does not affect the left motor circuit due to the short circuit of the second applied voltage switch SW2.

In the case of the electronic parking brake system according to the present embodiment, a malfunction due to disconnection in the circuit diagram can be seen as a case where a short circuit appears between the left motor and the right motor in Fig.

A method of detecting a malfunction according to the paragraph of FIG. 4 will be described in detail below.

When the first applied voltage switch SW1 is turned on and the second applied voltage switch SW2 is turned off, the expected voltage of the second motor monitoring point (node 2) 42 is 0 [v] because Vdd2 is not applied, However, if the measured voltage of the first motor monitoring point (node 1) 41 is not 0 [v] when the disconnection occurs with the first motor monitoring point (node 1) 41, It can be seen that the disconnection between the circuits 200 and 300 has occurred.

Further, when the second applied voltage switch SW2 is turned on and the first applied voltage switch SW1 is turned off, the expected voltage of the first motor monitoring point (node 1) 41 is 0 [ v], but if the measured voltage is not 0 [v] at the second motor monitoring point (node 2) 42 when a disconnection occurs with the second motor monitoring point (node 2) 42, It can be seen that a disconnection has occurred between the motor drive circuits 200 and 300.

FIG. 5 is a graph of the voltage change of the motor over time during normal operation, and FIG. 6 is a graph of the motor voltage change with time when the inter-motor short circuit occurs.

The first motor monitoring point (node 1) 41 and the second motor monitoring point (node 2) 42 in FIG. 4 are contacts for measuring the voltage of the motor. In the embodiment described below, the half of the applied voltage (Vdd1 / 2, Vdd2 / 2) is measured as normal operation. Further, the applied voltages Vdd1 and Vdd2 may be the same.

In the normal operation, when the first applied voltage switch SW1 is on, the measured voltage of the first motor monitoring point (node 1) 41 of the motor 1 is Vdd1 / 2 [v]. At this time, since the second applied voltage switch SW2 is off, the measured voltage of the second motor monitoring point (node 2) 42 of the motor 2 in normal operation is 0 [v].

Further, in the normal operation, when the second applied voltage switch SW2 is on, the measured voltage of the second motor monitoring point (node 2) 42 of the motor 2 is Vdd2 / 2 [v]. At this time, since the first applied voltage switch SW1 is off, the measured voltage of the first motor monitoring point (node 1) 41 of the motor 1 in normal operation is 0 [v].

The first motor monitoring point (node 1) 41 and the second motor monitoring point (node 2) 42 _ in FIG. 5 are contacts for measuring the voltage of the motor. In the embodiment described later, half of the applied voltage (Vdd1 / 2, Vdd2 / 2) is measured to be normal operation.

However, when a short circuit occurs between the first motor and the second motor, the normal voltage due to the operation of the applied voltage switch is not measured.

The voltage values of the applied voltages Vdd1 and Vdd2 can be set to be the same.

5, when the second applied voltage switch SW2 is on, the measured voltage of the second motor monitoring point (node 2) of the motor 2 is Vdd2 / 2 [v]. At this time, since the first applied voltage switch SW1 is off, the measured voltage of the first motor monitoring point (node 1) 41 of the motor 1 in normal operation should be 0 [v] The first motor monitoring point (node 1) 41 and the second motor monitoring point (node 2) 42 are brought into the same contact so that the first motor monitoring point (node 1) A value of Vdd2 / 2 is measured, not a value of 0 [v]. Therefore, it can be judged as a malfunction.

7 is a flowchart for explaining a control method of the electronic parking brake system according to the present invention.

According to the present embodiment, the electronic parking brake apparatus judges whether the first motor and the second motor are operating (10). That is, when the electronic parking brake of the present application is applied or released by the MCU 100, the brake is in an operating state. When the brake is in the operating state 10, the flowchart is restarted.

When the first motor and the second motor are not in operation (No in 10), the first applied voltage switch is turned on and the second applied voltage switch is turned off (20).

Specifically, when the brake is not applied or released, the operation of the brake may be interpreted as a brake applied.

Thereafter, the voltages of the first motor monitoring point (node 1) and the second motor monitoring point (node 2) are measured, and whether the voltage measured at the first motor monitoring point (node 1) is Vdd1 / It is determined whether the voltage measured at the monitoring point (node 2) is 0 [v]. (30)

If the voltage measured at the first motor monitoring point (node 1) is Vdd1 / 2 [v] and the voltage measured at the second motor monitoring point (node 2) is 0 [v] (60) because it is a malfunction due to disconnection between the first motor and the second motor.

If the voltage measured at the first motor monitoring point (node 1) is Vdd1 / 2 and the voltage measured at the second motor monitoring point (node 2) is 0 [V] (example of 20), Vdd1 is turned off and Vdd2 (40).

Thereafter, the voltages of the first motor monitoring point (node 1) and the second motor monitoring point (node 2) are measured, and whether the measured voltage at node 1 is Vdd1 / 2 [V] 0 [V] (50).

If the voltage measured at the second motor monitoring point (node 2) is Vdd2 [v] and the voltage measured at the first motor monitoring point (node 1) is 0 [v] (example of 50) .

If the voltage measured at the second motor monitoring point (node 2) is Vdd2 [v] and the voltage measured at the first motor monitoring point (node 1) is not 0 [v] A warning is issued (60) that a circuit breakdown has occurred and is malfunctioning.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limited to the embodiments set forth herein; It will be understood that various modifications may be made without departing from the spirit and scope of the invention.

100: MCU 400: Display
200: right motor drive 300: left motor drive
a: Right motor b: Left motor
2: Left motor circuit diagram 3: Right motor circuit diagram
41: First motor monitoring point (node 1)
42: Second motor monitoring point (node 2)
31: Impedance
21: first short detection circuit 22: second short detection circuit
23:
61: Electronic booster

Claims (7)

A first motor;
A first motor drive circuit for interrupting or supplying power to the first motor;
A second motor;
A second motor drive circuit for interrupting or supplying power to the second motor;
A short detection part for detecting a short circuit between the first motor drive circuit and the second motor drive circuit;
An MCU for determining a short circuit between the first motor drive circuit and the second motor drive circuit according to the output of the short detection portion;
And a display unit for alerting the user of a short circuit between the first motor drive circuit and the second motor drive circuit. The method according to claim 1,
Wherein when the power supplied to the first motor and the second motor of the vehicle is cut off, the MCU judges a short circuit between the first motor drive circuit and the second motor drive circuit. 3. The method of claim 2,
Wherein the short detection portion includes a first short detection circuit connected to the first motor drive and a second short detection circuit connected to the second motor drive. The method of claim 3,
Wherein the MCU is configured to apply a first voltage to the first short detection circuit and to determine a short circuit between the first motor drive circuit and the second motor drive circuit in accordance with the output of the second short detection circuit . 5. The method of claim 4,
When the first voltage is applied to the first short detection circuit and the output value of the second short detection circuit is not 0 [V], the MCU has the short circuit between the first motor drive circuit and the second motor drive circuit Electronic parking brake system to judge. The method of claim 3,
Wherein the MCU applies a second voltage to the second short detection circuit and judges a short circuit between the first motor drive circuit and the second motor drive circuit in accordance with the output of the first short detection circuit . The method according to claim 6,
When the second voltage is applied to the second short detection circuit, if the output value of the first short detection circuit is not 0 [V], the MCU has the short circuit between the first motor drive circuit and the second motor drive circuit Electronic parking brake system to judge.

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