CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2020-0111396, filed on Sep. 2, 2020, the disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to an electric control unit of an electric parking brake system.

BACKGROUND ART

Recently released vehicles use an electric parking brake (EPB) device that electronically controls the driving of a parking brake, and the EPB device is mounted on a general disk brake to perform the function of a parking brake.

The electric parking brake device may automatically operate or release a parking brake according to the control determination of an electronic control unit (ECU) that performs a simple switch operation or overall control even though the driver does not manually operate the parking brake. The electric parking brake device is configured with an actuator that drives a motor for generating a braking force and a micro control unit (MCU) for driving the actuator.

Recently, as interest in autonomous vehicles or electric vehicles has increased, the brake system has also Teen developed, such as using an electronic master booster instead of a hydraulic system. As a result, the integrated dynamic brake (IDB) system has been developed, in which the anti-lock brake system (ABS) and the electric stability control (ESC) system are integrated. Since the TDB system may control not only a service brake operated during normal driving but also a parking brake, it is possible to reduce the size and weight of the brake system and provide various functions, while also significantly improving stability.

Since the TDB system includes a large number of electronic devices in many parts, the ECU includes a plurality of MCUs to increase the reliability of operation of the electric parking brake system. Therefore, even when a fault occurs in any one of the plurality of MCUs, at least one parking brake may still be operated. However, there is a problem in that costs are increased when each of the plurality of MCUs is formed as a multicore to implement the electric parking brake system. In order to solve this problem, there is a need to minimize costs when the electric parking brake system is implemented and secure redundancy of the electric parking brake system so that even when a fault occurs in any one of the plurality of MCUs, at least one parking brake may still be operated to secure safety.

DISCLOSURE
Technical Problem

The exemplary embodiments of the present disclosure for solving these conventional problems provide a control unit of an electric parking brake system that drives at least one actuator by using the other MCU when a fault occurs in any one MCU among a plurality of MCUs.

In addition, the exemplary embodiments of the present disclosure provide a control unit of an electric parking brake system in which a cut-off circuit is implemented in any one actuator.

Technical Solution

The control unit of an electric parking brake system according to an exemplary embodiment of the present disclosure includes a first MCU (micro control unit) having a driver circuit including a first driver circuit and a second driver circuit respectively connected to a first motor and a second motor for providing a driving force to an electric parking brake to control the first motor and the second motor, and a plurality of core processors to control the first driver circuit and the second driver circuit connected according to reception of an electric parking brake (EPB) switch signal, a second MCU having one core processor and connected to the second driver circuit, a first switch for connecting the first sub-MCU and the second driver circuit, and a second switch for connecting the second sub-MCU and the second driver circuit.

In addition, the main MCU performs communication with the first sub-MCU and the second sub-MCU through a data bus.

In addition, the control unit further includes a watchdog counter for monitoring an operation of the second sub-MCU from the outside of the second sub-MCU.

In addition, the second switch is turned off when the first sub-MCU operates normally.

In addition, the second sub-MCU receives the EPB switch signal through in-vehicle communication when a fault occurs in the first sub-MCU, and turns on the second switch to control the second driver circuit.

In addition, the control unit further includes a third switch for connecting the first sub-MCU and the first driver circuit.

In addition, the control unit further includes a fourth switch for connecting the second sub-MCU and the first driver circuit.

In addition, when the first sub-MCU operates normally, the first switch and the third switch are turned on to control the first driver circuit and the second driver circuit.

In addition, the second sub-MCU receives the EPB switch signal through in-vehicle communication when a fault occurs in the first sub-MCU, and turns on the second switch and the fourth switch to control the first driver circuit and the second driver circuit.

In addition, the second driver circuit further includes a cut-off switch for preventing a malfunction of the second sub-MCU when the first sub-MCU operates normally, wherein the cut-off switch is provided between a low arm of the second driver circuit and a ground.

Moreover, the control unit of an electric parking brake system according to an exemplary embodiment of the present disclosure includes a driver circuit including a first driver circuit and a second driver circuit respectively connected to a first motor and a second motor for providing a driving force to an electric parking brake to control the first motor and the second motor; a first sub-MCU (micro control unit) having at least one processor to control the first driver circuit and the second driver circuit connected according to reception of an electric parking brake (EPB) switch signal, a second sub-MCU having at least one core processor and connected to the second driver circuit, a main MCU for controlling communication between the first sub-MCU and the second sub-MCU, a first switch for connecting the first sub-MCU and the second driver circuit, and a second switch for connecting the second sub-MCU and the second driver circuit.