CONTROL DEVICE OF BRAKE SYSTEM

A control device of a brake system, according to the present invention, includes, as redundancy, a first control unit for controlling the valve, the motor and the like of a brake system by receiving a sensor unit input, and a second control unit capable of performing the same function as the first control unit when the first control unit malfunctions, and thus the present invention can control the brake system of a vehicle by using the second control unit in an emergency situation in which the first control unit does not normally operate.

TECHNICAL FIELD

The present invention relates to a brake for a vehicle, and more particularly, to technology for controlling a brake.

BACKGROUND ART

A brake system is absolutely necessary for a vehicle. This is because a vehicle that cannot be stopped cannot travel. Therefore, for the safety of passengers, the stability of a brake system cannot be emphasized enough.

Recently, as an interest in autonomous vehicles and electric vehicles has increased, brake systems have also been required to have stronger braking power and stability. To this end, an electronic master booster has been used instead of the conventional hydraulic system, and an integrated dynamic brake (IDB) system, in which an anti-lock brake system (ABS) and an electronic stability control (ESC) system are integrated, has been developed. The use of such an IDB system has made it possible to reduce the size and weight of a brake system and has brought results of providing various functions and significantly improving stability.

However, since such an IDB system includes many electronic devices, the IDB system always has a risk of a failure. When, during driving of a vehicle, a brake system fails and is in an inoperable state, it can lead to a serious accident, and thus, it is necessary to prepare for the inoperable state of the brake system.

The inventors of the present invention have made efforts to solve the problems of brake systems according to the related art. The inventors of the present invention have completed the present invention after much effort to complete a system capable of normally operating a brake system in response to an unexpected situation even when a part of the brake system fails.

DISCLOSURE

Technical Problem

The present invention is directed to providing a brake system in which an entire system can operate normally even when a part of the system fails.

Meanwhile, other objects of the present invention which are not explicitly stated will be further considered within the scope easily deduced from the following detailed description and the effects thereof.

Technical Solution

According to an exemplary embodiment of the present invention, a control device of a brake system includes a sensor unit including at least one of a pedal sensor, a pressure sensor, and a motor position sensor, a first control unit which includes at least one of an electronic parking brake (EPB) driver, a valve driver, and a motor driver and includes a first microcontroller unit (MCU) configured to control the EPB driver, the valve driver, and the motor driver according to a signal received from the sensor unit, and a second control unit which performs the same function as the first control unit and constitutes redundancy of the first control unit.

The second control unit may operate only when the first control unit does not operate normally.

The valve driver may include a valve driver included in a separate chip, a valve driver included in a first application specific integrated circuit (ASIC) chip included in the first control unit, and a valve driver included in a second ASIC chip included in the second control unit.

The valve drivers included in the first and second ASIC chips may drive valves for a function of an electronic stability control (ESC) system or an anti-lock brake system (ABS), and the valve driver included in the separate chip may drive valves for a foot brake function.

The first control unit may include a first motor driver and a first three-phase inverter, the second control unit may include a second motor driver and a second three-phase inverter, and the first MCU or the second MCU may control a dual winding motor which is simultaneously connected to the first three-phase inverter of the first control unit and the second three-phase inverter of the second control unit.

When the first control unit fails, the second control unit may control the dual winding motor only with the second three-phase inverter and the second motor driver.

The first control unit may include a first car area network (CAN) transceiver, the second control unit may include a second CAN transceiver, and the first MCU and the second MCU may communicate with each other through the first CAN transceiver and the second CAN transceiver.

The first MCU and the second MCU may communicate with each other through general purpose input/output (GPIO) or universal asynchronous receiver/transmitter (UART).

The first control unit may receive a signal value of a sensor connected to the second control unit through the first CAN transceiver, or the second control unit may receive a signal value of a sensor connected to the first control unit through the second CAN transceiver.

The pressure sensor may include a first pressure sensor, a second pressure sensor, and a third pressure sensor, the first pressure sensor and the second pressure sensor may be connected only to the first control unit, and the third pressure sensor may be connected only to the second control unit.

When the first control unit fails, the second control unit may control the brake system only with the third pressure sensor in a state in which performance is degraded as compared with a case in which all of the first, second, and third pressure sensors operate.

The pedal sensor may include an output of a first channel and an output of a second channel, the output of the first channel may be connected to the first control unit, and the output of the second channel may be connected to the second control unit.

The output of the first channel and the output of the second channel of the pedal sensor may output different values according to settings, and when the first control unit fails, the output of the second channel may output the same value as the output of the first channel before the first control unit fails.

Advantageous Effects

According to the present invention, by providing redundant control units having the same structure, even when one control unit fails, the redundant control unit performs the same function, and thus, it is possible to cope with an emergency situation, thereby increasing stability.

Meanwhile, even if the effects are not explicitly mentioned here, the effects described in the following specification, which are expected by the technical characteristics of the present invention, and the provisional effects thereof are handled as described in the specification of the present invention.

※ The accompanying drawings are included to provide a further understanding of the technical idea of the present invention, and thus the scope of the present invention is not limited thereto.

MODES OF THE INVENTION

Hereinafter, a configuration of the present invention guided by various exemplary embodiments of the present invention and effects resulting from the configuration will be described with reference to the accompanying drawings. In describing the present invention, the detailed descriptions of the related known-functions that are obvious to a person skilled in the art and would unnecessarily obscure the subject of the present invention are omitted.

Terms such as “first,” “second,” and the like may be used to describe various components, but the components should not be limited by the above terms. The terms may be used only for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, a “first component” may be called a “second component,” and similarly, a “second component” may also be called a “first component.” In addition, a singular expression may include a plural expression, unless otherwise specified. The terms used in the exemplary embodiments of the present invention may be interpreted with the commonly known meaning to those of ordinary skill in the relevant technical field unless otherwise specified.

Hereinafter, a configuration of the present invention guided by various exemplary embodiments of the present invention and effects resulting from the configuration will be described with reference to the accompanying drawings.

FIG. 1is a schematic structural diagram of the entirety of a brake system according to one exemplary embodiment of the present invention.

The brake system includes a reservoir1110, a master cylinder1120, a hydraulic pressure supply device1130, a hydraulic control unit1140, a dump control unit1180, valves and sensors for controlling channels, and an electronic control unit (ECU) for controlling the components.

The reservoir1110stores a pressure medium that flows along a flow path to generate pressure. The pressure medium flows to a required place according to an adjustment of a valve. A simulator valve1111aformed in a flow path of the reservoir1110controls a flow of a pressure medium between the reservoir1110and the master cylinder1120. During normal operation, the simulator valve1111ais opened so that a user links the reservoir1110and the master cylinder1120. In an abnormal operation mode, the simulator valve1111ais closed so that a pressure medium of the master cylinder1120is transferred to valves for controlling wheel cylinders through a backup flow path.

When a driver presses a brake pedal, the master cylinder1120pressurizes and discharges a pressure medium such as brake oil accommodated therein. Thus, the master cylinder1120provides a reaction force according to a braking depression force to the driver. A cut valve1121acontrols a flow in a backup flow path between the master cylinder1120and the valves for controlling the wheel cylinders.

The hydraulic pressure supply device1130generates hydraulic pressure according to a position of a pedal and transmits the hydraulic pressure to the wheel cylinders of wheels1011,1012,1013, and1014, whereby a vehicle is braked. The hydraulic pressure supply device1130includes a motor to generate hydraulic pressure.

The hydraulic control unit1140controls the hydraulic pressure provided from the hydraulic pressure supply device1130.

The dump control unit1180controls a flow of a pressure medium between the reservoir1110and the hydraulic pressure supply device1130.

Each valve opens or closes a flow path formed between the reservoir1110and the master cylinder1120or the reservoir1110and the hydraulic pressure supply device1130to control a flow of a pressure medium. The valves are provided as check valves formed to allow only one direction flow without the need for control or solenoid valves of which opening and closing are controlled under control of an ECU10.

Inlet valves1161a,1161b,1151a,and1151bcontrol a flow of a pressure medium supplied from the hydraulic pressure supply device1130to the wheel cylinders.

Outlet valves1162aand1162bcontrol a flow of a pressure medium discharged from the wheel cylinders to the reservoir1110.

Furthermore, other outlet valves1171aand1171bcontrol a flow of a pressure medium between the wheel cylinders and the master cylinder1120.

A diagnostic valve1191is used when a diagnostic mode of examining a failure of other valves or a leak in a flow path is performed.

The ECU10receives signals from sensors40,62,64, and66and controls the respective valves or the motor included in the hydraulic pressure supply device1130to control the operation of the brake system.

FIG. 2is a more detailed structural diagram of a brake control device according to an exemplary embodiment of the present invention.

As described above, the ECU10controls valves, motors, and the like in response to a sensor input.

To this end, the ECU10may include a control unit equipped with a microcontroller unit (MCU).

The ECU10of the present invention includes a first control unit100and a second control unit200so as to constitute redundancy.

The first control unit100includes a first MCU110, a first valve driver150, a first application specific integrated circuit (ASIC) chip120, a first electronic parking brake (EPB) driver130, and a first motor driver170which are controlled by the first MCU110.

The first MCU110controls the first EPB driver130or a second EPB driver230according to a signal of an EPB switch70to operate a first parking brake82or a second parking brake84. In order to detect a parking state, a speed of wheels1011,1012,1013, and1014is input from a wheel speed sensor (WSS)90. A signal of the WSS90is decoded by the first ASIC chip120and transmitted to the first MCU110.

The first MCU110controls a motor20in response to an input of a pedal sensor40. Accordingly, the pedal sensor40may be included in the ECU10.

A signal of a first channel42of the pedal sensor40is transmitted to the first MCU110of the first control unit100, and a signal of a second channel44thereof is transmitted to a second MCU210of the second control unit200.

The first MCU110detects a position of a pedal using the signal of the first channel42of the pedal sensor40and thus controls the motor20of a hydraulic pressure supply device1130. In order to drive the motor20, the first control unit100includes a first motor driver170and a first inverter180. The first inverter180is a three-phase inverter and is connected to a connector of the motor20to drive the motor20. The first channel42and the second channel44of the pedal sensor40may output the same signal or different signals according to settings. When different signals are output, the first MCU110and the second MCU210may exchange the different signals through car area network (CAN) communication or the like. In addition, in a situation in which a signal cannot be received from the first MCU110due to a situation such as a failure of the first control unit100, the second pedal sensor44may be set to output the same signal as the first pedal sensor42.

The first MCU110and the second MCU210may communicate with each other through a first communication unit160or a second communication unit260or may communicate with a vehicle CAN communication unit. Alternatively, the first MCU110and the second MCU210may be directly connected to transmit or receive signals through a general purpose input/output (GPIO) or universal asynchronous receiver/transmitter (UART) interface. Accordingly, the first MCU110may also receive a signal of a sensor connected only to the second MCU210through a communication interface between the MCUs.

A motor position sensor (MPS) is required for more precise driving of the motor20. To this end, a first MPS32and a second MPS34may be included in the ECU10and connected to the first control unit100and the second control unit200, respectively.

The MPSs32and34are positioned in the vicinity of a magnet22of the motor20to measure an accurate rotational position of the motor. The first MCU110precisely controls the motor20by receiving accurate position information of the motor20from the first MPS32.

In order to control valves50and51in the first MCU110, valve drivers are required. To this end, the first control unit100and the second control unit200may include valve drivers150and250provided in separate chips, or a first ASIC chip120may include valve drivers.

FIG. 3illustrates structures of valve drivers and controlled valves according to an exemplary embodiment of the present invention in more detail.

The valve drivers may include valve drivers included in the first ASIC chip120and valve drivers150provided in separate chips.

Valves included in a first valve group50controlled by the first ASIC chip120are inlet valves1161a,1161b,1151a,and1151bfor controlling a transfer of a pressure medium of the hydraulic pressure supply device1130to wheel cylinders. The inlet valves may be normal open type solenoid valves that are opened in a normal situation and are closed under control of a valve driver.

The valves may also be outlet valves1162aand1162bfor controlling a flow of a pressure medium discharged from the wheel cylinders. The outlet valves may be normal close type solenoid valves that are closed in a normal situation and are opened by a valve driver. Alternatively, the valves may be dump valves1181and1182that control a flow in a flow path between a reservoir1110and the hydraulic pressure supply device1130.

The valves driven by the first ASIC chip120may be valves that are operated not only in a situation in which a driver generally presses a brake pedal but also in a situation in which a brake system is operated, for example, by a control device such as an electronic stability control (ESC) system or an anti-lock brake system (ABS).

Valves controlled by the valve drivers150provided in the separate chips may include valves that are operated when the driver presses the brake pedal in a normal situation.

Valves included in a second valve group52controlled by the valve drivers150provided in the separate chips may include relief valves1141and1142for controlling flow paths between the hydraulic pressure generation device1130and the wheel cylinders, outlet valves1171aand1171bfor controlling flow paths between a master cylinder1120and the wheel cylinders, a simulator valve1111afor forming a pedal feeling, and a cut valve1121afor controlling backup flow paths between the master cylinder1120and the wheel cylinders. A valve driver (not shown) for controlling a diagnostic valve1191may also be controlled by the valve driver provided in the separate chip.

A second ASIC chip220or valve drivers250included in a second control unit200may also perform the same functions as the first ASIC chip120or the valve drivers150of the first control unit100.

Returning toFIG. 2again, the first MCU110may receive signals from a first pressure sensor62and a second pressure sensor64to control valves.

The first pressure sensor62may be a pedal simulator pressure (PSP) sensor for forming a pedal feeling, and the second pressure sensor64may be a circuit pressure (CIRP) sensor for measuring pressure between the hydraulic pressure supply device1130and wheel cylinders.

For brake control, the first MCU110may use signals of a third pressure sensor66as well as signals of the first and second pressure sensors62and64. Since the third pressure sensor66is connected only to the second MCU210, a pressure value may be transmitted and used through communication between the MCUs as described above.

The second control unit200includes the same components as the first control unit100to constitute redundancy of the first control unit100.

To this end, the second control unit200includes the second MCU210, the second ASIC chip220, the second EPB driver230, the valve drivers250, and a second motor driver270.

An output of the second channel44of the pedal sensor40is input to the second control unit200and transmitted to the second MCU210, and if necessary, an output of the first channel42may also be used by being received through a second CAN transceiver260or the like.

In a situation in which the first MCU110or the first EPB driver230does not operate, the second MCU210may control both an RL parking brake82and an RR parking brake84through the second EPB driver230.

The second ASIC chip220decodes an input of the WSS90to transmit the decoded output to the second MCU210and includes some valve drivers. A distinction between valve drivers included in an ASIC chip and valve drivers provided in separate chips is as described above.

The second MCU210drives the motor20through the second motor driver270and more precisely controls the motor20through the second MPS34. To this end, the motor20may be a dual winding motor that is controlled by both a first inverter180and a second inverter280being connected thereto. In a situation in which the first control unit100does not operate normally, the motor20receives power only from the second inverter280. Therefore, an operation in a degraded state in which only one winding among dual windings is connected is performed.

In addition, only the third pressure sensor66among the pressure sensors is connected to the second MCU210. In a general situation in which the first control unit100operates normally, the first pressure sensor62and the second pressure sensor64are connected to the first MCU110, and the third pressure sensor66is connected to the second MCU210to transmit a signal to the first MCU110through a communication channel. Accordingly, the first MCU110may control valves using signals of all three pressure sensors.

However, in a state in which the first control unit100does not operate normally, the second MCU210may not receive signals from the first and second pressure sensors62and64. Accordingly, the second MCU210controls the brake system in a degraded state only with a signal from the third pressure sensor66.

In a brake control system according to the present invention as described above, there may be provided a brake system capable of, by constituting redundancy, even when a part of a system fails, securing a braking force through the remaining system.

The protection scope of the present invention is not limited to the disclosure and expressions of the exemplary embodiment clearly described above. In addition, it is added that the protection scope of the present invention is not limited by modifications and substitutions obvious to the technical field to which the present invention pertains.