Electronic parking brake system and control method thereof

Abstract

The invention relates to an electronic parking brake system and a control method thereof. The system comprises a gear shifting device, a main parking brake controller and an auxiliary parking brake controller. When a parking gear is input into the gear shifting device, the gear shifting device sends a parking request signal. The main parking brake controller determines whether the main parking brake control can be executed when the main parking brake controller receives the parking request signal, executes the main parking brake control when the main parking brake controller determines that the main parking brake control can be executed, and executes the main parking brake control when the main parking brake controller cannot be executed. And the main parking brake controller sends a fault signal to the gear shifting device. When the shift device receives the fault signal, the shift device activates the auxiliary parking brake controller to perform the auxiliary parking brake control. The auxiliary parking brake controller performs auxiliary parking brake control based on the parking request signal in the activated state. The EPB ECU is subjected to double configuration, and safe parking is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control, and in particular to an electronic parking brake system and a control method thereof. Background Art

[0002] Motor vehicles use transmission systems to provide one or more drive states. Transmission systems include a transmission that uses various gears and gear trains to transform torque from a rotating power source. In automatic transmission systems, the transmission typically includes a parking pawl that selectively engages a notched gear to lock the gear train, thereby parking the vehicle. When the driver manipulates the shift lever from the drive (D) gear or the reverse (R) gear to the park (P) gear, the parking pawl engages a notch in the notched gear.

[0003] With the popularity of electric vehicles, the Electronic Parking Brake (EPB) integrates the temporary braking function during driving and the long-term braking function after parking, and realizes the parking brake through electronic control. Its use is becoming more and more widespread. However, with the increase in the degree of electrification, some problems have also emerged. For example, if the EPB Electronic Control Unit (ECU) fails during the driving of the vehicle and cannot perform the braking function, it will cause a serious accident.

[0004] At present, some vehicle manufacturers implement the safety protection of P-gear parking by setting two EPB ECUs. However, when one EPB ECU fails, the spare EPB ECU can only be used once, which cannot ensure the fail-safety of the EPB system. Some vehicle manufacturers also add additional EPB ECUs and relays, which increases the hardware cost and the size of the EPB system. Therefore, there is an urgent need for an electronic parking brake system and a control method thereof that can ensure the fail-safety of the EPB system without significantly increasing the hardware cost.

[0005] The above description of the background technology is only for facilitating an in-depth understanding of the technical solution of the present invention (such as the technical means used, the technical problems solved and the technical effects produced), and should not be regarded as an admission or any form of implication that the information constitutes prior art already known to those skilled in the art. Summary of the invention

[0006] The present invention provides an electronic parking brake system and a control method thereof, which can duplicate some components of the EPB, and ensure that when a control circuit fails, the other circuit can still provide the parking brake function, so that the driver can park the vehicle safely.

[0007] According to an embodiment of the present invention, an electronic parking brake system is provided, the system comprising a shifting device, a main parking brake controller and an auxiliary parking brake controller. The shifting device is configured to send a parking request signal when a parking gear is input. The main electronic parking brake is configured to determine whether the main parking brake control can be performed when a parking request signal is received from the shifting device, perform the main parking brake control when it is determined that the main parking brake control can be performed, and send a fault signal to the shifting device when it is determined that the main parking brake control cannot be performed. The auxiliary parking brake controller is configured to perform the auxiliary parking brake control based on the parking request signal received from the shifting device in an activated state. The shifting device is configured to activate the auxiliary parking brake controller when a fault signal is received from the main parking brake controller so that the auxiliary parking brake controller performs the auxiliary parking brake control.

[0008] The shift device may include a shift button and a vehicle control unit. The shift button may be configured to input a shift position through a driver's operation. The vehicle control unit may be configured to request a shift control of the vehicle based on the shift position input into the shift button to send a shift request signal.

[0009] The main parking brake controller may be configured to: when determining that the main parking brake control can be performed, perform the main parking brake control by controlling the operation of the double-sided calipers; after the main parking brake control is completed, send a feedback signal indicating the status of the double-sided calipers to the vehicle control unit.

[0010] The vehicle control unit may be configured to: upon receiving a fault signal from the main parking brake controller, send an activation signal to the auxiliary parking brake controller to activate the auxiliary parking brake controller; and upon determining that the auxiliary parking brake controller is in an activated state, send a parking request signal to the auxiliary parking brake controller.

[0011] The auxiliary parking brake controller can be configured as follows: when receiving an activation signal from a vehicle control unit, the auxiliary parking brake controller changes from an inactive state to an active state; and sends an activation state signal to the vehicle control unit indicating that the auxiliary parking brake controller is in an activated state, so that the vehicle control unit determines that the auxiliary parking brake controller is in an activated state based on the received activation state signal.

[0012] The auxiliary parking brake controller can be configured to: when receiving a parking request signal from a vehicle control unit in an activated state, perform auxiliary parking brake control by controlling the operation of a single-sided caliper; after the auxiliary parking brake control is completed, send a feedback signal indicating the state of the single-sided caliper to the vehicle control unit.

[0013] The main parking brake controller can be electrically connected to the vehicle control unit via the first communication channel and the second communication channel, and the auxiliary parking brake controller can be electrically connected to the vehicle control unit via the first communication channel and the second communication channel; when a communication failure occurs in the first communication channel, the communication between the main parking brake controller and the vehicle control unit and the communication between the auxiliary parking brake controller and the vehicle control unit can be achieved via the second communication channel.

[0014] The first communication channel may include a first CAN local area network of the CAN network; the second communication channel may include a second CAN local area network, a third CAN local area network and a central gateway of the CAN network.

[0015] The electronic parking brake system may further include an electronic parking brake switch, which is configured to input an electronic parking signal through the driver's operation; the main parking brake controller may be configured to: when receiving the electronic parking signal input from the electronic parking brake switch, perform the main parking brake control by controlling the operation of the double-sided calipers.

[0016] The primary parking brake controller and the secondary parking brake controller may be configured in the same control device.

[0017] The main parking brake controller and the auxiliary parking brake controller may be configured in different control devices.

[0018] According to another embodiment of the present invention, a control method for an electronic parking brake system is provided, the electronic parking brake system comprising a gear button, a vehicle control unit, a main parking brake controller and an auxiliary parking brake controller, the control method comprising: when the gear button enters the parking gear, the vehicle control unit sends a parking request signal; when the main parking brake controller receives the parking request signal from the vehicle control unit, the main parking brake controller determines whether the main parking brake control can be performed, when the main parking brake controller determines that the main parking brake control cannot be performed, the main parking brake controller sends a fault signal to the vehicle control unit; when the vehicle control unit receives the fault signal from the main parking brake controller, the vehicle control unit activates the auxiliary parking brake controller; and when the auxiliary parking brake controller receives the parking request signal from the vehicle control unit in an activated state, the auxiliary parking brake controller performs the auxiliary parking brake control.

[0019] The control method further includes: when the main parking brake controller determines that the main parking brake control can be performed, the main parking brake controller performs the main parking brake control by controlling the operation of the double-sided calipers; and after the main parking brake controller completes the main parking brake control, the main parking brake controller sends a feedback signal indicating the status of the double-sided calipers to the vehicle control unit.

[0020] The control method further includes: when the vehicle control unit receives a fault signal from the main parking brake controller, the vehicle control unit sends an activation signal to the auxiliary parking brake controller to activate the auxiliary parking brake controller; when the auxiliary parking brake controller receives the activation signal from the vehicle control unit, the auxiliary parking brake controller changes from an inactive state to an active state, and sends an activation state signal to the vehicle control unit indicating that the auxiliary parking brake controller is in an activated state; and the vehicle control unit determines that the auxiliary parking brake controller is in an activated state based on the received activation state signal, and when the vehicle control unit determines that the auxiliary parking brake controller is in an activated state, the vehicle control unit sends a parking request signal to the auxiliary parking brake controller.

[0021] The control method further includes: when the auxiliary parking brake controller receives a parking request signal from a vehicle control unit in an activated state, the auxiliary parking brake controller performs auxiliary parking brake control by controlling the operation of the single-sided caliper; after the auxiliary parking brake controller completes the auxiliary parking brake control, the auxiliary parking brake controller sends a feedback signal indicating the state of the single-sided caliper to the vehicle control unit.

[0022] The main parking brake controller can be electrically connected to the vehicle control unit via the first communication channel and the second communication channel, and the auxiliary parking brake controller can be electrically connected to the vehicle control unit via the first communication channel and the second communication channel; when a communication failure occurs in the first communication channel, the communication between the main parking brake controller and the vehicle control unit and the communication between the auxiliary parking brake controller and the vehicle control unit can be achieved via the second communication channel.

[0023] The first communication channel may include a first CAN local area network of the CAN network; the second communication channel may include a second CAN local area network, a third CAN local area network and a central gateway of the CAN network.

[0024] The electronic parking brake system may further include an electronic parking brake switch, and the control method may further include: the electronic parking brake switch receives an electronic parking signal operated by a driver, and in response to the main parking brake controller receiving an electronic parking signal input from the electronic parking brake switch, the main parking brake controller performs main parking brake control by controlling the operation of double-sided calipers.

[0025] The primary parking brake controller and the secondary parking brake controller may be configured in the same control device.

[0026] The main parking brake controller and the auxiliary parking brake controller may be configured in different control devices.

[0027] The present invention adopts the above technical solution, which has the following beneficial effects:

[0028] The present invention omits the transmission parking configuration according to the prior art, and realizes controller duplication by using the main parking brake controller and the auxiliary parking brake controller. If the main parking brake controller fails, the vehicle control unit can activate the auxiliary parking brake controller, send a parking request to the auxiliary parking brake controller, and then the auxiliary parking brake controller will control the caliper installed on the driving wheel, thereby realizing parking safety when the main parking brake controller fails.

[0029] In addition, the main parking brake controller and the auxiliary parking brake controller are both connected to the first communication path and the second communication path to realize CAN communication duplication. If the first communication path fails, the second communication path will send messages normally to realize parking safety when the communication line fails. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The following will describe the exemplary embodiments of the present invention in more detail with reference to the accompanying drawings. For the sake of clarity, the same components in different drawings are shown with the same reference numerals. It should be noted that the drawings are only for illustration and are not necessarily drawn to scale. In these drawings:

[0031] Figure 1 Two parking systems according to the prior art are shown schematically.

[0032] Figure 2 is a block diagram of an electronic parking brake system according to an embodiment of the present invention.

[0033] Figure 3 is a detailed structural diagram of an EPB according to an embodiment of the present invention.

[0034] Figure 4A and Figure 4B Schematic diagram of the connection between the main parking brake controller, the auxiliary parking brake controller, the first communication path, and the second communication path according to an embodiment of the present invention.

[0035] Figure 5 2 is a schematic diagram of a communication method among a vehicle control unit, a central gateway, a main parking brake controller and an auxiliary parking brake controller according to an exemplary embodiment of the present invention.

[0036] Figure 6 It is a table diagram of the fail-safe strategy when different types of failures occur in EPB.

[0037] 7A to 7D Schematic diagram of signal transmission between various components in an electronic parking brake system according to an embodiment of the present invention under different conditions.

[0038] Figure 8 is a flowchart of a control method of an electronic parking brake system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The implementation scheme of the present invention is described in detail below. This implementation scheme is implemented on the premise of the technical scheme of the present invention, and a detailed implementation method and specific operation process are given, but the protection scope of the present invention is not limited to the implementation scheme described below.

[0040] Figure 1 Two electronic parking systems according to the prior art are schematically shown. Figure 1 As shown, according to Figure 1 In a conventional electronic parking system for a vehicle shown on the left, when the parking (P) gear position is input in the shift by wire (SBW) system, the controller of the transmission performs the parking function by operating the transmission parking mechanism. Figure 1 In another electronic parking system of a vehicle of the prior art shown on the right, when an electronic parking brake (EPB) switch is pressed to request parking control of the vehicle, the EPB electronic control unit (ECU) operates the brakes installed on the driving wheels to put the brakes in a parking brake state.

[0041] However, the electronic parking brake system according to the embodiment of the present invention can omit the transmission parking configuration according to the related art, and solve the problem in the related art that the EPB ECU cannot realize the parking function in the event of a failure.

[0042] Reference Figure 2 The configuration of the electronic parking brake system will be described in detail. Figure 2 is a block diagram of an electronic parking brake system according to an embodiment of the present invention. Figure 2 As shown, the electronic parking brake system may include: a shift device 100 , a main parking brake controller 210 , an auxiliary parking brake controller 220 , an EPB switch (SW) 300 , a caliper 400 , and a driving wheel 500 .

[0043] The shift device 100 requests the parking control of the vehicle when the parking gear is input through the operation of the driver. In a specific example, the shift device 100 may include a shift input device 110 and a vehicle control unit (VCU) 120. The shift input device 110 may adopt a button-type control, such as a gear button, but the present invention is not limited to this. The driver can input the parking (P) gear, the reverse (R) gear, the neutral (N) gear or the drive (D) gear by operating the gear button. The VCU 120 can request the shift control of the vehicle through the gear input by the gear button.

[0044] The VCU 120 may be electrically connected to the main parking brake controller 210 and the auxiliary parking brake controller 220, respectively. The main parking brake controller 210 may perform the main parking brake control based on the parking request signal received from the VCU 120, and when receiving the parking request signal from the VCU 120, the main parking brake controller 210 determines whether the main parking brake control can be performed, and when determining that the main parking brake control cannot be performed, sends a fault signal to the VCU 120. The auxiliary parking brake controller 220 may perform the auxiliary parking brake control based on the parking request signal received from the VCU 120 in an activated state. When the VCU 120 receives a fault signal from the main parking brake controller 210, the VCU 120 may be configured to: activate the auxiliary parking brake controller 220 so that the auxiliary parking brake controller 220 performs the auxiliary parking brake control.

[0045] Therefore, according to the embodiment of the present invention, the VCU 120 can directly request the parking control of the vehicle from the main parking brake controller 210 and the auxiliary parking brake controller 220 without going through the transmission parking configuration according to the prior art. In addition, the electronic parking brake system performs a redundancy configuration of the EPB ECU by configuring the auxiliary parking brake controller 220, ensuring that the auxiliary parking brake controller 220 can still provide the parking brake function when the main parking brake controller (i.e., EPB ECU) 210 fails, thereby ensuring safe parking.

[0046] Specifically, when the main parking brake controller 210 receives the parking request signal from the VCU 120, the main parking brake controller 210 may determine whether the parking brake control can be performed. When the main parking brake controller 210 determines that the main parking brake control can be performed, the main parking brake controller 210 may perform the main parking brake control by controlling the operation of the double-sided caliper 400. After the main parking brake control is completed, the main parking brake controller 210 sends a feedback signal indicating the state of the double-sided caliper to the VCU 120.

[0047] When the main parking brake controller 210 determines that the main parking brake control cannot be performed, the main parking brake controller 210 may send a fault signal to the VCU 120. When the VCU 120 receives the fault signal from the main parking brake controller 210, the VCU 120 may send an activation signal to the auxiliary parking brake controller 220 to activate the auxiliary parking brake controller 220.

[0048] When the auxiliary parking brake controller 220 receives the activation signal from the VCU 120 , the auxiliary parking brake controller 220 may change from the inactive state to the active state and send an activation state signal to the VCU 120 , the activation state signal indicating that the auxiliary parking brake controller 220 is in the active state.

[0049] The VCU 120 may determine that the auxiliary parking brake controller 220 is in the activated state based on the received activation state signal. When the VCU 120 determines that the auxiliary parking brake controller 220 is in the activated state, the VCU 120 may send a parking control signal to the auxiliary parking brake controller 220.

[0050] When the auxiliary parking brake controller 220 receives a parking request signal from the VCU 120 in an activated state, the auxiliary parking brake controller 220 performs auxiliary parking brake control by controlling the operation of the single-sided caliper. After the auxiliary parking brake control is completed, the auxiliary parking brake controller 220 may send a feedback signal indicating the state of the single-sided caliper to the VCU 120.

[0051] According to an embodiment of the present invention, the main parking brake controller 210 may include a main microcontroller unit (MCU) and a main driver. The main MCU is used to generate a control signal and send the control signal to the main driver, and the main driver operates according to the received control signal. Similarly, the auxiliary parking brake controller 220 may include an auxiliary MCU and an auxiliary driver.

[0052] According to one embodiment of the present invention, the main parking brake controller 210 and the auxiliary parking brake controller 220 can be integrated into the same control device, for example, they can be integrated into the integrated electric brake (IEB) 200, or they can be integrated into different control devices, for example, the main parking brake controller is integrated into the IEB, and the auxiliary parking brake controller is integrated into the integrated control unit (ICU). When the main parking brake controller 210 and the auxiliary parking brake controller 220 are integrated into the same control device, the electronic parking brake system can be implemented at a lower cost. When the main parking brake controller 210 and the auxiliary parking brake controller 220 are integrated into different control devices, a protection measure can be provided for the failure of the connector (i.e., an additional failure safety guarantee), thereby improving the reliability of the electronic parking brake system.

[0053] The caliper 400 includes a first motor on caliper (MOC) 410 and a second MOC 420. The first MOC 410 and the second MOC 420 are installed at two driving wheels 500 of the vehicle and connected to the IEB 200. Specifically, the main parking brake controller 210 is connected to the first MOC 410 and the second MOC 420, respectively. When the main parking brake controller 210 receives a parking control request, the main parking brake controller 210 operates the first MOC 410 and the second MOC 420 to put the first MOC 410 and the second MOC 420 in a parking brake state. The auxiliary parking brake controller 220 is connected only to the second MOC 420. When the auxiliary parking brake controller 220 receives a parking control request in an activated state, the auxiliary parking brake controller 220 operates only the second MOC 420. The first MOC 410 and the second MOC 420 may be installed on both rear wheels, but the present invention is not limited thereto and may be installed on the front wheels of the vehicle according to the vehicle type. For example, the first MOC is installed on the right rear wheel and the second MOC is installed on the left rear wheel.

[0054] Each of the first MOC 410 and the second MOC 420 can be configured to convert the rotational power of the motor into translational motion via the lead screw nut during parking control, so that the two brake pads apply pressure to the brake disc to generate braking force. Each of the first MOC 410 and the second MOC 420 can also be configured to release the brake disc pressure through a motor control opposite to the motor control in the above-mentioned parking control.

[0055] In addition to the shift input device 110 being able to input the parking gear position and request the parking control of the vehicle, the EPB switch 300 can input the electronic parking signal by the driver's operation. When the electronic parking signal of the EPB switch 300 is input, the main parking brake controller 210 can perform the main parking brake control by controlling the operation of the double-sided caliper 400, that is, the main parking brake controller 210 operates the first MOC 410 and the second MOC 420 installed on the driving wheel to adjust the vehicle to the parking brake state. However, the EPB switch 300 cannot operate the auxiliary parking brake controller 220.

[0056] Figure 3 Detailed structural diagram of IEB according to an embodiment of the present invention. Figure 3 As shown, in addition to the above-mentioned duplication configuration of the EPBECU (or, MCU) to ensure that the auxiliary parking brake controller can still provide the parking brake function when the main parking brake controller (i.e., EPB ECU) fails, other components can also be configured to be duplicated in the IEB. For example, the IEB can be configured with a dual power supply, i.e., including a first power supply (VBAT1) and a second power supply (VBAT2). The wheel speed sensor (Wheel Speed ​​Sensor, WSS) of the rear wheel can also be configured to be duplicated.

[0057] In one example, the main parking brake controller can be set in an integrated dynamic brake (IDB), which is constructed by integrating an anti-lock brake system (ABS) and an electronic stability control system (ESC). The IDB can achieve miniaturization and lightness of the brake system.

[0058] The electronic parking brake system according to the embodiment of the present invention can operate in a normal mode (ie, a case where the main parking brake controller is in a normal state) and an IDB failure mode (ie, a case where the main parking brake controller fails).

[0059] In normal mode, the two MOCs (i.e., the first MOC and the second MOC) installed on the rear wheels on both sides can be operated by the integrated dynamic brake (IDB) and the EPB switch. Specifically, when the parking signal of the EPB switch is input, the IDB can operate the two MOCs to adjust the vehicle to the parking brake state.

[0060] In the IDB fault mode, the auxiliary parking brake controller controls only the MOC installed on one side (e.g., the left side) of the rear wheel. Specifically, the VCU can activate the auxiliary parking brake controller and send the received parking request signal to the auxiliary parking brake controller, and the auxiliary parking brake controller can put the MOC on the left side into the parking brake state according to the received parking control request signal.

[0061] Return to see Figure 2 According to an embodiment of the present invention, the IEB 200 and the VCU 120 can communicate via the first communication channel 610 and the second communication channel 620. Specifically, the main parking brake controller 210 is electrically connected to the VCU 120 via the first communication channel 610 and the second communication channel 620, and the auxiliary parking brake controller 220 is electrically connected to the VCU 120 via the first communication channel 610 and the second communication channel 620. When a communication failure occurs in the first communication channel 610, the communication between the main parking brake controller 210 and the VCU 120, and the communication between the auxiliary parking brake controller 220 and the VCU 120 can be realized via the second communication channel 620.

[0062] Will refer to Figure 4A and Figure 4B The connection between the main parking brake controller, the auxiliary parking brake controller, the first communication channel, and the second communication channel according to an embodiment of the present invention will be described in detail. The first communication channel and the second communication channel may be communication channels based on a controller area network (CAN) or a controller area network with flexible data rate (CAN_FD).

[0063] refer to Figure 4A and Figure 4B , CAN_FD 1 can be used as the communication network of the first communication path, and CAN_FD 2 can be used as the communication network of the second communication path, but the present invention is not limited thereto. Figure 4A As shown, the main MCU included in the main parking brake controller can be connected to CAN_FD 1 and CAN_FD 2, respectively, and the auxiliary MCU included in the auxiliary parking brake controller can be connected to CAN_FD 1 and CAN_FD 2, respectively. Figure 4A The connections shown are different. Figure 4B The connection shown reduces the number of pins and thus reduces the need for a CAN controller.

[0064] According to an exemplary embodiment of the present invention, the first communication channel may include a first CAN local area network CAN1 of a CAN network, and the second communication channel includes a second CAN local area network CAN2, a third CAN local area network CAN3 and a central gateway (Center Gate Way, CGW) of the CAN network. For example, the first CAN local area network CAN1 may be a first powertrain CAN local area network, the second CAN local area network CAN2 may be a chassis control CAN local area network, the third CAN local area network CAN3 may be a second powertrain CAN local area network, and the central gateway (CGW) is used to forward signals between various CAN local area networks to achieve interconnection between the local area networks.

[0065] Figure 5 Schematic diagram showing the communication mode among the VCU, the central gateway, the main parking brake controller and the auxiliary parking brake controller according to an exemplary embodiment of the present invention. Figure 5 As shown, the VCU 120 is connected to the main parking brake controller 210 and the auxiliary parking brake controller 220 through the first CAN local area network CAN1 to form a first communication path. The VCU 120 is connected to the central gateway 700 through the third CAN local area network CAN3, and the central gateway 700 is connected to the main parking brake controller 210 and the auxiliary parking brake controller 220 through the second CAN local area network CAN2 to form a second communication path.

[0066] Figure 6 It is a table diagram of the fail-safe strategy when different types of failures occur in EPB. Figure 6 As shown, when the main MCU fails, the auxiliary MCU has the control authority of EPB so that the brake can operate normally. When the auxiliary MCU fails, the main MCU still implements normal EPB control. When CAN1, which is the first communication path, fails, the main MCU can still implement normal EPB control through the second communication path. When CAN2, which is part of the second communication path, fails, the main MCU can still implement normal EPB control through the first communication path.

[0067] 7A to 7D is a schematic diagram of signal transmission between various components (ie, VCU 120, CGW 700, primary parking brake controller 210, auxiliary parking brake controller 220, first MOC 410, and second MOC 420) in the electronic parking brake system according to an embodiment of the present invention in different situations.

[0068] Fig. 7A2 shows the signal transmission between the VCU 120, the CGW 700, the primary parking brake controller 210, the auxiliary parking brake controller 220, the first MOC 410 and the second MOC 420 in a normal operating state. Fig. 7A As shown, both the first MOC 410 and the second MOC 420 are controlled by the main parking brake controller 210. When the parking gear position is input by the operation of the driver, the VCU 120 sends a parking control request signal to the main parking brake controller 210, thereby locking the first MOC 410 and the second MOC 420. When a shift gear position other than the parking gear position is input by the operation of the driver, the VCU 120 sends a parking release request signal to the main parking brake controller 210, thereby releasing the first MOC 410 and the second MOC 420. Specifically, the VCU 120 requests the parking control of the vehicle from the main parking brake controller 210 via the first CAN local area network CAN1, and at the same time, the VCU 120 sequentially requests the parking control of the vehicle from the main parking brake controller 210 via the third CAN local area network CAN3, the central gateway, and the second CAN local area network CAN2, so that the dual-channel CAN communication between the VCU 120 and the main parking brake controller 210 is realized, thereby avoiding the problem that the parking request signal cannot be sent from the VCU 120 to the main parking brake controller 210 when only the first CAN local area network CAN1 has a communication failure. At this time, the main parking brake controller 210 can send a feedback signal of the status of the first MOC 410 and the second MOC 420 to the VCU 120. The auxiliary parking brake controller 220 is in a standby (i.e., inactive) state and can send a standby state signal to the VCU 120.

[0069] Figure 7B FIG. 4 shows the signal transmission between the VCU 120, the CGW 700, the main parking brake controller 210, the auxiliary parking brake controller 220, the first MOC 410 and the second MOC 420 when a communication failure occurs in the first CAN local area network CAN1. Figure 7B As shown, in the case of having the second communication path, the main parking brake controller 210 can still control the first MOC 410 and the second MOC 420 to lock or release.

[0070] Figure 7C FIG. 2 shows signal transmission between the VCU 120, the CGW 700, the main parking brake controller 210, the auxiliary parking brake controller 220, the first MOC 410, and the second MOC 420 in the event of a failure of the main parking brake controller 210. Figure 7CAs shown, the main parking brake controller 210 fails, but the first communication path and the second communication path are still usable. This may be caused by an error in a driver integrated circuit (IC) included in the main parking brake controller 210.

[0071] In this case, the main parking brake controller 210 cannot control the first MOC 410 and the second MOC 420. The main parking brake controller 210 may send a fault signal to the VCU 120 through the first communication path and / or the second communication path. When the VCU 120 receives the fault signal from the main parking brake controller 210, the VCU 120 operates the second MOC 420 through the auxiliary parking brake controller 220, that is, the VCU 120 sends an activation signal to the auxiliary parking brake controller 220 to activate the auxiliary parking brake controller 220. After the auxiliary parking brake controller 220 receives a parking request signal or a parking release request signal in the activated state, the second MOC 420 is placed in the parking brake state or the second MOC 420 is released from the parking brake state. In addition, the auxiliary parking brake controller 220 may send a feedback signal of the state of the second MOC 420 to the VCU 120.

[0072] Fig.7D FIG. 2 shows signal transmission between the VCU 120 , the CGW 700 , the main parking brake controller 210 , the auxiliary parking brake controller 220 , the first MOC 410 , and the second MOC 420 when both the main parking brake controller 210 and the first communication path fail. Fig.7D As shown, the main parking brake controller 210 fails, and the first communication path (i.e., the first CAN local area network CAN1) cannot communicate. This may be caused by an error in the main MCU included in the main parking brake controller 210, or an error in the application specific integrated circuit (ASIC) of the main MCU.

[0073] In this case, the main parking brake controller 210 cannot control the first MOC 410 and the second MOC 420. The communication between the main parking brake controller 210 and the first communication path times out, and the VCU 120 does not receive a signal via the first communication path within a predetermined time. However, the main parking brake controller 210 can send a fault signal to the VCU 120 through the second communication path (i.e., the third CAN local area network, the second CAN local area network, and the central gateway). When the VCU 120 receives the fault signal from the main parking brake controller 210, the VCU 120 operates the second MOC 420 through the auxiliary parking brake controller, that is, the VCU 120 sends a parking request signal or a parking release request signal to the auxiliary parking brake controller 220 through the second communication path, so that the second MOC 420 is in a parking brake state or the second MOC 420 is released from the parking brake state. In addition, the auxiliary parking brake controller 220 can send a status signal of the second MOC 420 to the VCU 120.

[0074] According to an embodiment of the present invention, the electronic parking brake system may further include a combined instrument panel, which may display information about the shift operation of the shift device to the driver. For example, the combined display panel may visually display the shift position information based on any one of the D position, R position, N position, and P position of the shift device 100.

[0075] In a specific embodiment, the combined display board can be connected to a central gateway. The central gateway can use different heterogeneous communication protocols to connect the VCU, IEB and the combined display board to each other to achieve CAN communication between the VCU, IEB and the combined display board.

[0076] Figure 8 : is a flow chart of a control method of an electronic parking control system according to an embodiment of the present invention. Figure 8 , a control method among the VCU 120 , the main parking brake controller 210 , and the auxiliary parking brake controller 220 of the electronic parking brake system according to an embodiment of the present invention is shown.

[0077] When the auxiliary parking brake controller 220 is in the inactive state, the auxiliary parking brake controller 220 may send a standby state signal to the VCU 120 ( S16 ), the standby state signal indicating that the auxiliary parking brake controller 220 is in the inactive state.

[0078] When the driver operates the shift button (or the shift lever) to input the parking gear (S11), the VCU 120 can simultaneously request the parking control of the vehicle to the main parking brake controller 210 and the auxiliary parking brake controller 220, that is, send a parking request signal (S12). Since the auxiliary parking brake controller 220 is in an inactive state, the auxiliary parking brake controller 220 does not respond to the parking request signal. After the main parking brake controller 210 receives the parking request signal from the VCU 120, the main parking brake controller 210 determines whether the main parking brake control can be performed based on the parking request signal of the vehicle of the VCU 120 (S13). When the main parking brake controller 210 can perform the main parking brake control ("Yes" of S13), the main parking brake controller 210 operates the caliper installed on the driving wheel to put the caliper in the parking brake state. The caliper may include a first MOC and a second MOC respectively installed at two driving wheels of the vehicle, and therefore, the main parking brake controller 210 may operate the first MOC and the second MOC to park the vehicle (S14). In addition, when the main parking brake controller 210 operates the first MOC and the second MOC, the main parking brake controller 210 may send the locked or released state of the first MOC and the second MOC to the VCU 120 (S22).

[0079] When the main parking brake controller 210 cannot perform the main parking brake control based on the parking request signal of the vehicle of the VCU 120 ("No" of S13), the main parking brake controller 210 sends a fault signal to the VCU 120 (S15). When the VCU 120 receives the fault signal from the main parking brake controller 210, the VCU 120 activates the auxiliary parking brake controller 220 to operate the caliper. Specifically, the VCU 120 sends an activation signal to the auxiliary parking brake controller 220 (S17), and when the auxiliary parking brake controller 220 receives the activation signal from the VCU 120, the auxiliary parking brake controller 220 changes from an inactive state to an activated state, and sends an activation state signal indicating that the auxiliary parking brake controller is in an activated state to the VCU 120 (S18).

[0080] After the VCU 120 determines that the auxiliary parking brake controller is in the activated state based on the received activation state signal, it sends a parking request signal to the auxiliary parking brake controller 220 (S19). After the auxiliary parking brake controller 220 receives the parking request signal from the VCU 120, the auxiliary parking brake controller 220 may operate the second MOC to park the vehicle (S20). In addition, after the auxiliary parking brake controller 220 operates the second MOC, the auxiliary parking brake controller 220 may send the locked or released state of the second MOC to the VCU 120 (S21).

[0081] According to the embodiment of the present invention, the parking state of the vehicle is displayed to the driver by the combined instrument panel (S23).

[0082] The electronic parking brake system and control method thereof according to the embodiment of the present invention can omit the transmission parking configuration according to the prior art, and set an auxiliary MCU in the EPB to realize the duplication of MCU. In the EPB, two EPB MCUs are integrated in one IEB to realize the duplication of controller. In addition to the duplication of controller, there is also power supply duplication and WSS duplication, thereby strengthening the duplication.

[0083] Both EPB MCUs are connected to the first communication path and the second communication path to achieve CAN duplication. If the first communication path fails, the second communication path can send messages normally.

[0084] The electronic parking brake system and control method thereof according to the embodiment of the present invention also realizes the control logic duplication. If the main parking brake controller fails, the main parking brake controller will send a fault signal to the VCU, the VCU will send a parking request signal to the auxiliary parking brake controller, and then the auxiliary parking brake controller will control the MOC of the driving wheel in an activated state.

[0085] The various embodiments of the present invention are not exhaustive examples of all possible combinations, but are intended to describe representative aspects of the present invention, and what is described in various embodiments may be applied independently or in combinations of two or more.

[0086] The description presented in the above exemplary embodiments is only used to illustrate the technical solution of the present invention, and is not intended to be exhaustive, nor is it intended to limit the present invention to the precise form described. Obviously, it is possible for a person of ordinary skill in the art to make many changes and variations based on the above teachings. The exemplary embodiments are selected and described to explain the specific principles of the present invention and its practical application, so that other technicians in the field can easily understand, implement and use the various exemplary embodiments of the present invention and its various selected forms and modified forms. The scope of protection of the present invention is intended to be limited by the attached claims and their equivalent forms.

Claims

1. An electronic parking brake system, comprising: a shift device configured to send a parking request signal when a parking gear position is entered; a main parking brake controller configured to: determine whether the main parking brake control can be performed when receiving a parking request signal from the shift device, perform the main parking brake control when it is determined that the main parking brake control can be performed, and send a fault signal to the shift device when it is determined that the main parking brake control cannot be performed; as well as an auxiliary parking brake controller configured to: in an activated state, perform auxiliary parking brake control based on a parking request signal received from the shift device; The shift device is configured to activate the auxiliary parking brake controller when a fault signal is received from the main parking brake controller, so that the auxiliary parking brake controller performs auxiliary parking brake control.

2. The electronic parking brake system according to claim 1, wherein: The shifting device comprises: a gear position button configured to input a gear position through operation by a driver; and A vehicle control unit is configured to request a shift control of the vehicle based on a shift position input into a shift position button to send a shift request signal.

3. The electronic parking brake system according to claim 2, wherein: The main parking brake controller is configured as follows: When it is determined that the main parking brake control can be performed, the main parking brake control is performed by controlling the operation of the double-sided calipers; After the main parking brake control is completed, a feedback signal indicating the status of the double-sided calipers is sent to the vehicle control unit.

4. The electronic parking brake system according to claim 2, wherein: The vehicle control unit is configured as follows: When receiving a fault signal from the main parking brake controller, sending an activation signal to the auxiliary parking brake controller to activate the auxiliary parking brake controller; When it is determined that the auxiliary parking brake controller is in the activated state, a parking request signal is sent to the auxiliary parking brake controller.

5. The electronic parking brake system according to claim 4, wherein: The auxiliary parking brake controller is configured as follows: When receiving an activation signal from the vehicle control unit, the auxiliary parking brake controller changes from an inactive state to an active state; An activation state signal indicating that the auxiliary parking brake controller is in an activated state is sent to a vehicle control unit, so that the vehicle control unit determines that the auxiliary parking brake controller is in an activated state based on the received activation state signal.

6. The electronic parking brake system according to claim 5, wherein: The auxiliary parking brake controller is configured as follows: When a parking request signal is received from a vehicle control unit in an activated state, auxiliary parking brake control is performed by controlling the operation of a single-side caliper; After the auxiliary parking brake control is completed, a feedback signal indicating the state of the single-side caliper is sent to the vehicle control unit.

7. The electronic parking brake system according to claim 2, wherein: The main parking brake controller is electrically connected to the vehicle control unit via a first communication channel and a second communication channel, and the auxiliary parking brake controller is electrically connected to the vehicle control unit via a first communication channel and a second communication channel; When a communication failure occurs in the first communication channel, communication between the primary parking brake controller and the vehicle control unit and communication between the auxiliary parking brake controller and the vehicle control unit can be achieved via the second communication channel.

8. The electronic parking brake system according to claim 7, wherein: The first communication channel comprises a first CAN local area network of the CAN network; and The second communication channel includes a second CAN local area network, a third CAN local area network and a central gateway of the CAN network.

9. The electronic parking brake system according to claim 1, further comprising: an electronic parking brake switch configured to input an electronic parking signal through an operation of a driver; The main parking brake controller is configured to perform main parking brake control by controlling the operation of the double-sided calipers upon receiving an electronic parking signal input from an electronic parking brake switch.

10. The electronic parking brake system according to claim 1, wherein: The main parking brake controller and the auxiliary parking brake controller are arranged in the same control device.

11. The electronic parking brake system according to claim 1, wherein: The main parking brake controller and the auxiliary parking brake controller are configured in different control devices.

12. A control method of an electronic parking brake system, the electronic parking brake system comprising a shift button, a vehicle control unit, a main parking brake controller and an auxiliary parking brake controller, the control method comprising: When the gear button enters the parking gear, the vehicle control unit sends a parking request signal; When the main parking brake controller receives the parking request signal from the vehicle control unit, the main parking brake controller determines whether the main parking brake control can be performed. When the main parking brake controller determines that the main parking brake control cannot be performed, the main parking brake controller sends a fault signal to the vehicle control unit. When the vehicle control unit receives a fault signal from the main parking brake controller, the auxiliary parking brake controller is activated by the vehicle control unit; as well as When the auxiliary parking brake controller receives a parking request signal from the vehicle control unit in an activated state, the auxiliary parking brake control is performed by the auxiliary parking brake controller.

13. The control method of the electronic parking brake system according to claim 12, wherein: The control method further comprises: When the main parking brake controller determines that the main parking brake control can be performed, the main parking brake controller performs the main parking brake control by controlling the operation of the double-sided calipers; and After the main parking brake controller completes the main parking brake control, a feedback signal indicating the status of the double-sided calipers is sent by the main parking brake controller to the vehicle control unit.

14. The control method of the electronic parking brake system according to claim 13, wherein: The control method further comprises: When the vehicle control unit receives a fault signal from the main parking brake controller, the vehicle control unit sends an activation signal to the auxiliary parking brake controller to activate the auxiliary parking brake controller; When the auxiliary parking brake controller receives the activation signal from the vehicle control unit, the auxiliary parking brake controller changes from the inactive state to the active state, and sends an activation state signal indicating that the auxiliary parking brake controller is in the active state to the vehicle control unit; and The vehicle control unit determines that the auxiliary parking brake controller is in an activated state based on the received activation state signal. When the vehicle control unit determines that the auxiliary parking brake controller is in an activated state, the vehicle control unit sends a parking request signal to the auxiliary parking brake controller.

15. The control method of the electronic parking brake system according to claim 14, wherein: The control method further comprises: When the auxiliary parking brake controller receives a parking request signal from the vehicle control unit in an activated state, the auxiliary parking brake controller performs auxiliary parking brake control by controlling the operation of the single-side caliper; and After the auxiliary parking brake controller completes the auxiliary parking brake control, a feedback signal indicating the state of the single-side caliper is sent by the auxiliary parking brake controller to the vehicle control unit.

16. The control method of the electronic parking brake system according to claim 12, wherein: The main parking brake controller is electrically connected to the vehicle control unit via a first communication channel and a second communication channel, and the auxiliary parking brake controller is electrically connected to the vehicle control unit via a first communication channel and a second communication channel; When a communication failure occurs in the first communication channel, communication between the primary parking brake controller and the vehicle control unit and communication between the auxiliary parking brake controller and the vehicle control unit can be achieved via the second communication channel.

17. The control method of the electronic parking brake system according to claim 16, wherein: The first communication channel includes a first CAN local area network of the CAN network; The second communication channel includes a second CAN local area network, a third CAN local area network and a central gateway of the CAN network.

18. The control method of the electronic parking brake system according to claim 12, wherein the electronic parking brake system further comprises an electronic parking brake switch; The control method further comprises: An electronic parking brake switch receives an electronic parking signal operated by a driver; as well as In response to the main parking brake controller receiving the electronic parking signal input from the electronic parking brake switch, the main parking brake controller performs the main parking brake control by controlling the operation of the double-sided calipers.

19. The control method of the electronic parking brake system according to claim 12, wherein: The main parking brake controller and the auxiliary parking brake controller are arranged in the same control device.

20. The control method of the electronic parking brake system according to claim 12, wherein: The main parking brake controller and the auxiliary parking brake controller are configured in different control devices.

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