An EPB motor detection system and detection method

Abstract

The application discloses an EPB motor detection system and a detection method, and relates to the technical field of EPB motor detection systems, which can periodically check EPB hardware circuit faults in a stand-alone EPB, has low cost, and solves the high cost problem of a stand-alone EPB that uses an integrated EPB to detect hardware circuits and motors by relying on a stand-alone chip.

Description

TECHNICAL FIELD

[0001] The present application relates to an EPB motor detection system and a detection method, and belongs to the field of independent EPB control. BACKGROUND

[0002] At present, EPB is widely used in vehicles, mainly including independent EPB and integrated EPB, in which the hardware detection is completed by related chips in ESC.

[0003] In the prior art, the MGU control loop of a typical independent EPB controller is shown in Figure 1 , which includes current detection, voltage detection circuit, drive circuit and MGU. Since the left motor control loop and the right motor control loop are completely the same, Figure 2 and Figure 3 only the general arrangement scheme of the left motor control loop and the typical left motor drive circuit are described. Among them, the drive total enable is used to control the drive total enable switch, the clamping enable is used to control Sw1 and Sw4 to be closed, and Sw2 and Sw3 to be disconnected. The release enable is used to control Sw1 and Sw4 to be disconnected, and Sw2 and Sw3 to be closed.

[0004] However, if the independent EPB uses the special chip in the ESC for related hardware detection, the cost is high. The hardware detection circuit requires that the EPB detection circuit completes the short-circuit and open-circuit detection of the motor periodically during the self-checking process and the vehicle driving process, so as to ensure that the EPB system is always in normal working state and the driving safety is ensured. The existing EPB fault generally enters the corresponding failure mode when the MGU module is running. Since the working time of EPB accounts for a small proportion in the vehicle life cycle, it is relatively easy to occur related faults in the non-working state. SUMMARY

[0005] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art, and to provide an EPB motor detection system and a detection method, which periodically checks the EPB hardware circuit fault in the independent EPB, has low cost, and solves the high cost problem of detecting the hardware circuit and the motor by relying on independent chips in the integrated EPB.

[0006] In order to solve the above technical problems, the technical scheme of the present application is:

[0007] The present application provides an EPB motor detection system, which comprises an EPB main chip, an MGU drive circuit, a current detection circuit and an MGU module.

[0008] The EPB main chip is provided with a driving total enable pin, a first fault detection pin, a second fault detection pin and a fault detection enable pin, the EPB main chip sends a driving total enable signal to the MGU driving circuit through the driving total enable pin, the EPB main chip sends a fault detection enable signal to the MGU driving circuit through the fault detection enable pin, the EPB main chip sends a first fault detection signal to the MGU module through the first fault detection pin, and the EPB main chip sends a second fault detection signal to the MGU module through the second fault detection pin.

[0009] The output end of the MGU driving circuit is connected with the MGU module, and a current detection circuit is arranged in the working loop formed by the MGU driving circuit and the MGU module.

[0010] Further, the EPB main chip is further provided with a clamping enable pin and a release enable pin, the EPB main chip sends a clamping enable signal to the MGU driving circuit through the clamping enable pin, and the EPB main chip sends a release enable signal to the MGU driving circuit through the release enable pin.

[0011] Further, the model of the EPB main chip is MPC5604P.

[0012] The application further provides a detection method of the EPB motor detection system.

[0013] Step S1, after the vehicle ignition switch is turned on, the EPB main chip sends a fault detection enable signal to the MGU driving circuit to start fault detection;

[0014] Step S2, after the vehicle ignition, the EPB motor detection system performs a power-on self-checking stage.

[0015] Step S3, after the power-on self-checking stage ends for 200 ms, the EPB motor detection system enters a polling stage.

[0016] Further, the power-on self-checking stage includes a first self-checking stage and a second self-checking stage.

[0017] Further, in the power-on self-checking stage and the polling stage, the EPB main chip controls the pins as follows:

[0018] In the first self-checking stage, the first fault detection signal is a 7-periodic square wave signal composed of 10 ms high level and 150 ms low level;

[0019] In the second self-checking stage, the first fault detection signal remains low level.

[0020] After 100 ms from the start of the second self-check phase, the driving general enable signal is converted from low level to high level and the high level lasts for 20 ms;

[0021] In the second self-check phase, after the driving general enable signal is converted to high level for 2 ms, the second fault detection signal is converted to high level and the high level lasts for 15 ms.

[0022] Further, the step S2 specifically comprises the following steps:

[0023] Step S21, in the power-on self-check phase, the EPB master chip detects every time the first fault detection signal is high level, judges whether the MGU module exists fault in the power-on self-check phase according to the voltage of M_L+ and M_L- of the output end of the MGU driving circuit.

[0024] Step S22, in the case that the second fault detection signal is high level, if the current value obtained by the current detection circuit is greater than a given threshold, it is judged that the working loop composed of the MGU driving circuit and the MGU module exists fault.

[0025] Further, the step S21 of judging whether the MGU module exists fault in the power-on self-check phase specifically comprises the following steps:

[0026] If the voltage of M_L+ is continuously detected to be greater than 5.5V under the condition of 7 consecutive high levels of the first fault detection signal, it is judged that the MGU module is short-circuited with the power supply.

[0027] If the voltage of M_L+ is continuously detected to be less than 0.5V under the condition of 7 consecutive high levels of the first fault detection signal, it is judged that the MGU module is short-circuited with the ground.

[0028] If the voltage difference between M_L+ and M_L- is continuously detected to be greater than 1V under the condition of 7 consecutive high levels of the first fault detection signal, it is judged that the MGU module is open-circuited.

[0029] Further, the step S3 specifically comprises the following steps:

[0030] Step S31, in the polling phase, when the specified clamping or releasing driving instruction is executed, the first fault detection signal is set to low level, and the driving instruction is waited to be completed; after the driving instruction is completed for 200 ms, the first fault detection signal is sent again, and at this time, the first fault detection signal is a periodic square wave signal.

[0031] Step S32, judges whether the MGU module exists fault in the polling phase according to the voltage of M_L+ and M_L- of the output end of the MGU driving circuit.

[0032] Further, the step S32 judges whether the MGU module has a fault in the polling stage, and specifically includes the following steps:

[0033] If the voltage of M_L+ is greater than 5.5V continuously in the case of 5 high levels of the first fault detection signal, it is judged that the MGU module is short-circuited with the power supply.

[0034] If the voltage of the motor M_L+ is less than 0.5V continuously in the case of 5 high levels of the first fault detection signal, it is judged that the MGU module is short-circuited with the ground.

[0035] If the voltage difference between M_L+ and M_L- is greater than 1V in the case of 5 high levels of the first fault detection signal, it is judged that the MGU module is open-circuited.

[0036] By using the above technical scheme, compared with the original chip fault detection scheme, the present application only needs to increase passive components, without increasing the master control chip, and has great cost advantage. On the basis of the original control loop, the present application increases the finite element components and the master chip pin resources, realizes the real-time detection function of the MGU driving circuit, and improves the safety of the EPB system. The present application provides a fault detection solution for the independent EPB, and improves the safety of the independent EPB. The solution fully utilizes the related resources, reduces the probability of faults of the EPB in use, plays a role in early fault prediction, and is convenient for early maintenance. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 It is a principle block diagram of a typical scheme of the EPB system in the background art;

[0038] Figure 2 It is a principle block diagram of the left MGU control loop of the EPB system in the background art;

[0039] Figure 3 It is a typical left MGU driving circuit diagram in the background art;

[0040] Figure 4 It is a principle block diagram of the EPB motor detection system of the present application;

[0041] Figure 5 It is a left MGU driving circuit diagram of the present application;

[0042] Figure 6 It is a timing control diagram of each pin of the EPB master chip of the present application. DETAILED DESCRIPTION

[0043] In order to make the content of the present application more easily understood, the present application is further described in detail below according to specific embodiments and in combination with the drawings.

[0044] Example 1

[0045] like Figure 4 As shown, this embodiment provides an EPB motor detection system. Since the left MGU detection circuit and the right motor detection circuit are identical in the MGU control loop of the EPB controller, this embodiment uses the left motor circuit as an example for explanation. The EPB motor detection system of this embodiment includes an EPB main chip, an MGU drive circuit, a current detection circuit, and an MGU module. In this embodiment, the EPB main chip uses an MPC5604P microcontroller, and the MGU module is the motor module in the vehicle.

[0046] like Figure 4 As shown, the EPB main chip in this embodiment is provided with a drive enable pin, a first fault detection pin, a second fault detection pin, a fault detection enable pin, a clamping enable pin, and a release enable pin.

[0047] like Figure 4 As shown, in this embodiment, the EPB main chip sends a drive enable signal to the MGU drive circuit through the drive enable pin, a fault detection enable signal to the MGU drive circuit through the fault detection enable pin, a first fault detection signal to the MGU module through the first fault detection pin, and a second fault detection signal to the MGU module through the second fault detection pin. The EPB main chip also sends a clamping enable signal to the MGU drive circuit through the clamping enable pin and a release enable signal to the MGU drive circuit through the release enable pin.

[0048] Among them, such as Figure 5 As shown, the first fault detection pin of the EPB main chip is connected to the MGU module via a transistor, and the second fault detection pin of the EPB main chip is connected to the MGU module via switch Sw5. This embodiment adds a first fault detection signal and a second fault detection signal pin to the original MGU control loop. The second fault detection signal controls switch Sw5; when the signal is high, Sw5 is closed; when the signal is low, Sw5 is open.

[0049] like Figure 1 As shown, the output terminal of the MGU drive circuit in this embodiment is connected to the MGU module, and a current detection circuit is provided in the working circuit formed by the MGU drive circuit and the MGU module.

[0050] Example 2

[0051] This embodiment provides a detection method for an EPB motor detection system, which includes the following steps:

[0052] Step S1, after the vehicle ignition switch is turned on, the EPB main chip sends a fault detection enable signal to the MGU driving circuit to start fault detection. The fault detection enable signal is equivalent to the total switch of fault detection, and the entire fault detection process is opened through the fault detection enable signal;

[0053] Step S2, after the vehicle ignition, the EPB motor detection system performs a power-on self-test phase;

[0054] Step S3, after the power-on self-test phase ends for 200 ms, the EPB motor detection system enters a polling phase.

[0055] As shown in Figure 6 The power-on self-test phase of the embodiment includes a first self-test phase and a second self-test phase. In the power-on self-test phase and the polling phase, the EPB main chip controls the pins as follows:

[0056] In the first self-test phase, the first fault detection signal is a 7-periodic square wave signal composed of 10 ms high level and 150 ms low level.

[0057] In the second self-test phase, the first fault detection signal remains low.

[0058] After 100 ms after the start of the second self-test phase, the drive total enable signal is converted from low to high and remains high for 20 ms.

[0059] In the second self-test phase, 2 ms after the drive total enable signal is converted to high, the second fault detection signal is converted to high and remains high for 15 ms.

[0060] Specifically, step S2 of the embodiment specifically includes the following steps:

[0061] Step S21, in the power-on self-test phase, the EPB main chip detects every time the first fault detection signal is high. According to the voltage of M_L+ and M_L- of the output end of the MGU driving circuit, it is judged whether the MGU module has a fault in the power-on self-test phase. Wherein, judging whether the MGU module has a fault in the power-on self-test phase specifically includes the following steps:

[0062] If the voltage of M_L+ is continuously detected to be greater than 5.5V under the condition of 7 consecutive high levels of the first fault detection signal, it is judged that the MGU module is short-circuited to the power supply;

[0063] If the voltage of M_L+ is continuously detected to be less than 0.5V under the condition of 7 consecutive high levels of the first fault detection signal, it is judged that the MGU module is short-circuited to the ground;

[0064] If the voltage difference between M_L+ and M_L- is greater than 1V for 7 consecutive high levels of the first fault detection signal, it is determined that the MGU module is open circuit.

[0065] In step S22, if the current value obtained by the current detection circuit is greater than a given threshold value when the second fault detection signal is high, it is determined that there is a fault in the working loop formed by the MGU driving circuit and the MGU module. The threshold value can be calculated according to I=U / R, where U is 5V and R is the internal resistance of the motor.

[0066] Specifically, step S3 of the embodiment specifically includes the following steps:

[0067] In step S31, during the polling phase, when the specified clamping or releasing driving instruction is executed, the first fault detection signal is set to low, and the driving instruction is waited to be completed; after the driving instruction is completed for 200ms, the first fault detection signal is sent again, and at this time, the first fault detection signal is a periodic square wave signal.

[0068] In step S32, according to the voltage of M_L+ and M_L- at the output end of the MGU driving circuit, it is determined whether the MGU module has a fault in the polling phase. Specifically, whether the MGU module has a fault in the polling phase includes the following steps:

[0069] If the voltage of M_L+ is greater than 5.5V for 5 consecutive high levels of the first fault detection signal (the period in which the driving instruction causes the fault detection signal to terminate, and the previous period of this period, are not counted), it is determined that the MGU module is short-circuited with the power supply.

[0070] If the voltage of the motor M_L+ is less than 0.5V for 5 consecutive high levels of the first fault detection signal (the period in which the driving instruction causes the fault detection signal to terminate, and the previous period of this period, are not counted), it is determined that the MGU module is short-circuited with the ground.

[0071] If the voltage difference between M_L+ and M_L- is greater than 1V for 5 consecutive high levels of the first fault detection signal (the period in which the driving instruction causes the fault detection signal to terminate, and the previous period of this period, are not counted), it is determined that the MGU module is open circuit.

[0072] The above-described specific embodiments further illustrate the technical problems solved by the present application, technical solutions and beneficial effects. It should be understood that the above-described specific embodiments are merely specific embodiments of the present application and are not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An EPB motor detection system, characterized by: It includes an EPB main chip, an MGU driving circuit, a current detection circuit and an MGU module; The EPB main chip is provided with a driving total enable pin, a first fault detection pin, a second fault detection pin and a fault detection enable pin, the EPB main chip sends a driving total enable signal to the MGU driving circuit through the driving total enable pin, the EPB main chip sends a fault detection enable signal to the MGU driving circuit through the fault detection enable pin, the EPB main chip sends a first fault detection signal to the MGU module through the first fault detection pin, and the EPB main chip sends a second fault detection signal to the MGU module through the second fault detection pin; The EPB main chip detects every time the first fault detection signal is high, and judges whether the MGU module has a fault in the power-on self-checking stage according to the voltage of M_L+ and M_L- of the output end of the MGU driving circuit; In the case that the second fault detection signal is high, if the current value obtained by the current detection circuit is greater than a given threshold, it is judged that the working loop formed by the MGU driving circuit and the MGU module has a fault; The output end of the MGU driving circuit is connected with the MGU module, and the working loop formed by the MGU driving circuit and the MGU module is provided with a current detection circuit. 2.The EPB motor detection system of claim 1, wherein: The EPB main chip is further provided with a clamping enable pin and a release enable pin, the EPB main chip sends a clamping enable signal to the MGU driving circuit through the clamping enable pin, and the EPB main chip sends a release enable signal to the MGU driving circuit through the release enable pin. 3.The EPB motor detection system of claim 1, wherein: The model of the EPB main chip is MPC5604P.

4. The detection method of the EPB motor detection system according to any one of claims 1 to 3, characterized by, It includes the following steps: Step S1, after the vehicle ignition switch is turned on, the EPB main chip sends a fault detection enable signal to the MGU driving circuit, and starts fault detection; Step S2, after the vehicle ignition, the EPB motor detection system performs a power-on self-checking stage; Step S3, after the power-on self-checking stage ends for 200 ms, the EPB motor detection system enters a polling stage.

5. The method of claim 4, wherein: The power-on self-checking stage includes a first self-checking stage and a second self-checking stage.

6. The method of claim 5, wherein: In the power-on self-checking stage and the polling stage, the EPB main chip controls the pins as follows: In the first self-checking stage, the first fault detection signal is a 7-periodic square wave signal with 10 ms high level and 150 ms low level; In the second self-checking stage, the first fault detection signal remains low level; After 100 ms after the start of the second self-checking stage, the driving total enable signal is converted from low level to high level and the high level lasts for 20 ms; In the second self-checking stage, after the driving total enable signal is converted to high level for 2 ms, the second fault detection signal is converted to high level and the high level lasts for 15 ms.

7. The detection method according to claim 4, characterized in that, The step S2 specifically includes the following steps: Step S21, in the power-on self-test phase of the EPB motor detection system, the EPB main chip detects every time the first fault detection signal is high, judges whether the MGU module has a fault in the power-on self-test phase according to the voltage of M_L+ and M_L- of the output end of the MGU driving circuit. Step S22, in the case that the second fault detection signal is high, if the current value obtained by the current detection circuit is greater than the given threshold, it is judged that the working loop composed of the MGU driving circuit and the MGU module has a fault.

8. The detection method according to claim 7, characterized in that, The step S21 judges whether the MGU module has a fault in the power-on self-test phase, specifically including the following steps: If the voltage of M_L+ is continuously detected to be greater than 5.5V for 7 consecutive high levels of the first fault detection signal, it is judged that the MGU module is short-circuited with the power supply; If the voltage of M_L+ is continuously detected to be less than 0.5V for 7 consecutive high levels of the first fault detection signal, it is judged that the MGU module is short-circuited with the ground; If the voltage difference between M_L+ and M_L- is continuously detected to be greater than 1V for 7 consecutive high levels of the first fault detection signal, it is judged that the MGU module is open-circuited.

9. The detection method according to claim 4, characterized in that, The step S3 specifically includes the following steps: Step S31, in the polling phase, when the specified clamping or releasing driving instruction is executed, the first fault detection signal is set to low, and the driving instruction is waited to be completed; 200ms after the driving instruction is completed, the first fault detection signal is sent again, and at this time the first fault detection signal is a periodic square wave signal; Step S32, judges whether the MGU module has a fault in the polling phase according to the voltage of M_L+ and M_L- of the output end of the MGU driving circuit.

10. The detection method according to claim 9, characterized in that, The step S32 judges whether the MGU module has a fault in the polling phase, specifically including the following steps: If the voltage of M_L+ is continuously detected to be greater than 5.5V for 5 consecutive high levels of the first fault detection signal, it is judged that the MGU module is short-circuited with the power supply; If the voltage of M_L+ is continuously detected to be less than 0.5V for 5 consecutive high levels of the first fault detection signal, it is judged that the MGU module is short-circuited with the ground; If the voltage difference between M_L+ and M_L- is greater than 1V for 5 consecutive high levels of the first fault detection signal, it is judged that the MGU module is open-circuited.

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