Independent redundant wheel speed processing system and method

Abstract

The invention discloses an independent redundant wheel speed processing system. The system comprises four wheel speed sensors arranged on four wheels respectively; the four wheel speed sensors are respectively in communication connection with the MCU through the four wheel speed signal processing units; the four wheel speed signal processing units diagnose driving abnormity and wheel speed signal abnormity of the four wheel speed sensors respectively and send diagnosis results to the MCU. The independent wheel speed signal processing unit is adopted, the function safety requirement and the function redundancy requirement of the braking system are guaranteed, and meanwhile the high cost caused by the fact that a high-integration-level chip is adopted by the braking system to meet the function safety requirement and the function redundancy requirement is reduced.

Description

Technical Field

[0001] The present invention belongs to the field of vehicle control, and more specifically, the present invention relates to an independent redundant wheel speed processing system and method. Background Art

[0002] In order to realize the vehicle's driving brake control, parking brake control and body stability control functions, the brake controller of the vehicle's braking system needs to detect the four-way wheel speed signals input by the vehicle's four wheel speed sensors. After processing and monitoring the input signals, each sub-functional module calculates the four-way wheel speed, vehicle speed and slip rate results based on the input processed signals, and outputs drive actuators and signals to drive other actuators to operate.

[0003] In order to meet the requirements of functional safety, the wheel speed sensor detection circuit inside the brake controller needs to meet the requirements of functional safety in terms of diagnostic coverage and hardware failure rate. For vehicles equipped with autonomous driving functions, there will be functional redundancy requirements for the braking system, and the wheel speed sensor also needs to be designed with redundancy.

[0004] The existing design uses a highly integrated wheel speed acquisition chip. Each highly integrated wheel speed acquisition chip collects four wheel speed signals from four wheel speed sensors. When the highly integrated wheel speed acquisition chip fails, the four wheel speed signals of the four wheel speed sensors connected to it cannot be obtained. In order to meet the requirements of functional redundancy, the vehicle uses two highly integrated wheel speed acquisition chips, and the whole vehicle is equipped with eight wheel speed sensors, with two wheel speed sensors on each wheel. Figure 1 As shown, by adding hardware to meet functional safety and functional redundancy, the cost of the vehicle braking system is greatly increased. Summary of the invention

[0005] The present invention provides an independent redundant wheel speed processing system, aiming to improve the above-mentioned problem.

[0006] The present invention is implemented as follows: an independent redundant wheel speed processing system, the system comprising:

[0007] Four wheel speed sensors are respectively arranged on four wheels;

[0008] The four wheel speed sensors are respectively connected to the MCU through four wheel speed signal processing units;

[0009] The four wheel speed signal processing units diagnose the driving abnormalities and wheel speed signal abnormalities of the four wheel speed sensors respectively, and send the diagnosis results and the wheel speed signals output by the corresponding wheel speed sensors to the MCU.

[0010] Furthermore, the wheel speed signal processing unit includes: a drive diagnosis module for diagnosing drive abnormalities of the corresponding wheel speed sensor, the drive diagnosis module includes: a high-side drive diagnosis submodule and a low-side drive diagnosis submodule, wherein:

[0011] The high-side driver diagnosis submodule performs high-side driver fault diagnosis of the wheel speed sensor based on the high-side voltage;

[0012] The low-side drive diagnosis submodule performs fault diagnosis on the output signal of the wheel speed sensor based on the acquisition circuit, wherein each wheel sensor is configured with an independent power supply circuit and an acquisition circuit. The power supply circuit is used to power the wheel speed sensor, and the acquisition circuit is used to acquire the wheel speed signal.

[0013] Furthermore, the high-side driver diagnosis method is as follows:

[0014] An ADC sampling circuit for sampling the ADC value of the corresponding wheel speed sensor voltage is provided on the high side of each wheel speed sensor. The working voltage corresponding to the sampled ADC value is verified with the reference voltage value output by the MCU to detect whether the current working voltage of the wheel speed sensor is within the valid working voltage range. If the working voltage of the wheel speed sensor is within the valid working voltage range, it is determined that the high side drive of the corresponding wheel speed sensor is normal.

[0015] Furthermore, the wheel speed signal processing unit includes a wheel speed diagnosis module for diagnosing abnormal wheel speed signals, wherein the wheel speed signal diagnosis method is specifically as follows:

[0016] An ADC acquisition circuit for collecting the wheel speed pulse signal output by the wheel speed sensor is set at the interface of the input wheel speed pulse, and the amplitude of the collected wheel speed pulse signal is diagnosed. If the amplitude of the wheel speed pulse signal is within the set amplitude range, the wheel speed signal output by the wheel speed sensor is deemed valid.

[0017] Furthermore, a wheel speed signal verification module is integrated in the MCU to receive the valid wheel speed signals sent by the four wheel speed signal processing units and verify the valid wheel speed signals.

[0018] Furthermore, the verification process of the effective wheel speed signal is as follows:

[0019] The effective wheel speed signal during uniform speed driving is read, and the deviation of each wheel speed signal relative to other wheel speed signals is detected. If the deviation exceeds the set deviation threshold, the wheel speed sensor signal corresponding to the wheel speed signal is deemed invalid.

[0020] Furthermore, the system comprises:

[0021] Two MCUs, namely a master MCU and a slave MCU, and output ends of four wheel speed signal processing units are connected to the master MCU and the slave MCU respectively;

[0022] The master MCU and the slave MCU calculate the wheel speed signal of the corresponding wheel speed sensor based on the effective wheel speed pulse signal output by the wheel speed signal verification module.

[0023] Furthermore, the slave MCU will calculate the wheel speed signal of the corresponding wheel speed sensor based on the effective wheel speed pulse signal and send it to the master MCU; if the wheel speed signals calculated by the master MCU and the slave MCU are the same, it is determined that the master MCU has no fault.

[0024] The present invention is implemented as follows: an independent redundant wheel speed processing method based on the above-mentioned independent redundant wheel speed processing system, the method comprising the following steps:

[0025] S1. Collect high-side voltage signals of four wheel speed sensors and output signals of the acquisition circuit, detect whether the wheel speed sensor has a high-side drive fault based on the high-side voltage signal, and detect whether the acquisition circuit has a low-side drive fault based on the output signal of the acquisition circuit;

[0026] S2. If there is a high-side drive fault and / or a low-side drive fault, the corresponding wheel speed sensor is determined to be faulty. For the wheel speed sensor that does not have a high-side drive fault and a low-side drive fault, step S3 is executed;

[0027] S3, detecting whether the wheel speed information output by the wheel speed sensor is valid, if the detection result is yes, proceeding to step S4, if the detection result is no, determining that the corresponding wheel speed sensor state and signal failure;

[0028] S4. MCU verifies the valid wheel speed information, detects the failed wheel speed signal, and determines that the wheel speed sensor corresponding to the failed wheel speed signal is faulty.

[0029] The present invention adopts an independent and discrete wheel speed signal processing unit, which ensures the functional safety requirements and functional redundancy requirements of the braking system, and at the same time reduces the high cost of the braking system adopting a highly integrated chip to meet the functional safety and functional redundancy requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A block diagram of the hardware architecture of an existing wheel speed sensor interface provided by an embodiment of the present invention;

[0031] Figure 2 A schematic diagram of the structure of an independent redundant wheel speed processing system under a single MCU provided in an embodiment of the present invention;

[0032] Figure 3 A schematic diagram of the structure of an independent redundant wheel speed processing system under dual MCUs provided in an embodiment of the present invention;

[0033] Figure 4A flow chart of an independent redundant wheel speed processing method provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The specific implementation modes of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0035] Figure 2 The schematic diagram of the structure of the independent redundant wheel speed processing system provided by the embodiment of the present invention only shows the parts related to the embodiment of the present invention for the purpose of explanation. The system includes:

[0036] Four wheel speed sensors are respectively arranged on the four wheels, including: wheel speed sensor 1, wheel speed sensor 2, wheel speed sensor 3 and wheel speed sensor 4, and the four wheel speed sensors are respectively connected to the MCU through four wheel speed signal processing units;

[0037] The four wheel speed signal processing units diagnose the driving abnormalities and wheel speed signal abnormalities of the four wheel speed sensors respectively, and send the diagnosis results and the wheel speed signals output by the corresponding wheel speed sensors to the MCU.

[0038] In an embodiment of the present invention, four wheel speed sensors correspond to four wheel speed signal processing units, and each wheel speed signal processing unit includes: a drive diagnosis module and a wheel speed diagnosis module, which are respectively used to diagnose the drive abnormality and wheel speed signal abnormality of the corresponding wheel speed sensor, and upload the diagnosis results to the MCU.

[0039] The driver diagnosis module includes a high-side driver diagnosis submodule and a low-side driver diagnosis submodule, wherein:

[0040] (1) High-side drive diagnosis submodule: performs high-side drive diagnosis of the wheel speed sensor based on the high-side voltage;

[0041] An ADC sampling circuit is designed on the high side of the wheel speed sensor to sample the ADC value of the corresponding wheel speed sensor voltage. The working voltage corresponding to the sampled ADC value is verified with the reference voltage value output by the MCU to detect whether the current working voltage of the wheel speed sensor is within the valid working voltage range. If the working voltage of the wheel speed sensor is within the valid working voltage range, it is determined that the high side drive of the corresponding wheel speed sensor is normal.

[0042] (2) Low-side drive diagnosis submodule: performs low-side drive fault diagnosis of the wheel speed sensor based on the output information of the acquisition circuit;

[0043] The system includes: four power supply circuits for supplying power to four wheel speed sensors, and four acquisition circuits for collecting four-way wheel speed signals. When one of the acquisition circuits and / or power supply circuits fails, the power supply and wheel speed signal collection of the other three wheel speed sensors are not affected.

[0044] The acquisition circuit fault is diagnosed through the low-side driver diagnosis submodule, and the four wheel speed sensors correspond to four low-side driver diagnosis submodules.

[0045] (3) Wheel speed signal diagnosis based on wheel speed diagnosis module

[0046] An ADC acquisition circuit is designed at the interface of the input wheel speed pulse to collect the wheel speed pulse signal output by the wheel speed sensor and diagnose the amplitude of the wheel speed pulse signal. If the amplitude of the wheel speed pulse signal is within the set amplitude range, the wheel speed signal output by the wheel speed sensor is deemed valid and the corresponding wheel speed sensor pulse drive is deemed normal.

[0047] In an embodiment of the present invention, a wheel speed signal verification module is integrated in the MCU, which receives the valid wheel speed signals sent by the four wheel speed signal processing units and verifies the valid wheel speed signals. The verification process is as follows: reading the valid wheel speed signals during uniform speed driving, detecting the deviation of each wheel speed signal relative to other wheel speed signals, and if the deviations exceed the set deviation threshold, it is determined that the wheel speed sensor signal corresponding to the wheel speed signal is invalid, that is, it is determined that the wheel speed signal is not the actually collected wheel speed signal, and is an invalid wheel speed signal.

[0048] Figure 3 The present invention provides a schematic diagram of the structure of an independent redundant wheel speed processing system under dual MCUs. For the purpose of illustration, only the parts related to the present invention are shown. The system includes:

[0049] Two MCUs, namely a master MCU and a slave MCU, and output ends of four wheel speed signal processing units are connected to the master MCU and the slave MCU respectively;

[0050] Among them, the main MCU calculates the wheel speed signal of the corresponding wheel speed sensor based on the effective wheel speed pulse signal output by the wheel speed signal verification module;

[0051] The slave MCU calculates the speed signal of the corresponding wheel speed sensor based on the effective wheel speed pulse signal output by the wheel speed signal verification module, and at the same time, sends the detected speed signal and speed direction of the wheel speed sensor to the main MCU to verify the wheel speed signal. When the wheel speed signals calculated by the two are the same, it is determined that the main MCU has no fault.

[0052] In the embodiment of the present invention, since there is a lot of speed direction information

[0053] When the main MCU fails, if the slave MCU is normal, the slave MCU can still process the effective wheel speed pulse signal output by the wheel speed signal processing unit and output it to the required electronic control unit through the CAN interface.

[0054] The independent redundant wheel speed processing system provided by the present invention has the following beneficial technical effects:

[0055] (1) Four independent wheel speed signal processing units are designed to replace high-integration chips to collect wheel speed signals. From the perspective of functional safety, the wheel speed signal validity and synchronization are met. The wheel speed signal is diagnosed through software algorithms, and the four-way discrete design filters out the correlation interference of the wheel speed sensor signal to meet the independence requirements. A set of safety mechanism designs that meet functional safety is provided, and the timeliness of wheel speed signal fault diagnosis is improved. After the function is downgraded, the fault information will be sent to the HMI, and finally the fault information will be displayed on the instrument to warn the driver and the system enters a safe state. (2) From the perspective of functional redundancy, the four wheel speed sensor interfaces use four independent sensor interface circuits and two MCUs for redundant signal processing. After a single wheel speed sensor or acquisition circuit fails, the validity of the three-way wheel speed sensor signal can still be guaranteed. After a single MCU fails, the validity of the four-way wheel speed signal can still be guaranteed. After meeting the requirements of the braking system for functional safety and functional redundancy, the system cost of the vehicle's brake electronic control unit is reduced at the same time.

[0056] Figure 4 A flow chart of an independent redundant wheel speed processing method provided by an embodiment of the present invention, the method specifically comprises the following steps:

[0057] S1. Collect high-side voltage signals of four wheel speed sensors and output signals of the acquisition circuit, detect whether the wheel speed sensor has a high-side drive fault based on the high-side voltage signal, and detect whether the acquisition circuit has a low-side drive fault based on the output signal of the acquisition circuit;

[0058] S2. If there is a high-side drive fault and / or a low-side drive fault, the corresponding wheel speed sensor is determined to be faulty. For the wheel speed sensor that does not have a high-side drive fault and a low-side drive fault, step S3 is executed;

[0059] S3, detecting whether the wheel speed information output by the wheel speed sensor is valid, if the detection result is yes, proceeding to step S4, if the detection result is no, determining that the corresponding wheel speed sensor state and signal failure;

[0060] S4. MCU verifies the valid wheel speed information, detects the failed wheel speed signal, and determines that the wheel speed sensor corresponding to the failed wheel speed signal is faulty.

[0061] The present invention has been described exemplarily. Obviously, the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. An independent redundant wheel speed processing system, characterized in that: The system comprises: Four wheel speed sensors are respectively arranged on four wheels; The four wheel speed sensors are respectively connected to the MCU through four wheel speed signal processing units; The four wheel speed signal processing units diagnose the driving abnormalities and wheel speed signal abnormalities of the four wheel speed sensors respectively, and send the diagnosis results and the wheel speed signals output by the corresponding wheel speed sensors to the MCU.

2. The independent redundant wheel speed processing system according to claim 1, characterized in that: The wheel speed signal processing unit includes: a drive diagnosis module for diagnosing drive abnormalities of the corresponding wheel speed sensor, the drive diagnosis module includes: a high-side drive diagnosis submodule and a low-side drive diagnosis submodule, wherein: The high-side driver diagnosis submodule performs high-side driver fault diagnosis of the wheel speed sensor based on the high-side voltage; The low-side drive diagnosis submodule performs fault diagnosis on the output signal of the wheel speed sensor based on the acquisition circuit, wherein each wheel sensor is configured with an independent power supply circuit and an acquisition circuit. The power supply circuit is used to power the wheel speed sensor, and the acquisition circuit is used to acquire the wheel speed signal.

3. The independent redundant wheel speed processing system as claimed in claim 2, characterized in that: The high-side driver diagnosis method is as follows: An ADC sampling circuit for sampling the ADC value of the corresponding wheel speed sensor voltage is provided on the high side of each wheel speed sensor. The working voltage corresponding to the sampled ADC value is verified with the reference voltage value output by the MCU to detect whether the current working voltage of the wheel speed sensor is within the valid working voltage range. If the working voltage of the wheel speed sensor is within the valid working voltage range, it is determined that the high side drive of the corresponding wheel speed sensor is normal.

4. The independent redundant wheel speed processing system according to claim 1, characterized in that: The wheel speed signal processing unit includes a wheel speed diagnosis module for diagnosing abnormal wheel speed signals, wherein the wheel speed signal diagnosis method is specifically as follows: An ADC acquisition circuit for collecting the wheel speed pulse signal output by the wheel speed sensor is set at the interface of the input wheel speed pulse, and the amplitude of the collected wheel speed pulse signal is diagnosed. If the amplitude of the wheel speed pulse signal is within the set amplitude range, the wheel speed signal output by the wheel speed sensor is deemed valid.

5. The independent redundant wheel speed processing system according to claim 1, characterized in that: The MCU is integrated with a wheel speed signal verification module, which receives the valid wheel speed signals sent by the four wheel speed signal processing units and verifies the valid wheel speed signals.

6. The independent redundant wheel speed processing system as claimed in claim 5, characterized in that: The verification process of the effective wheel speed signal is as follows: The effective wheel speed signal during uniform speed driving is read, and the deviation of each wheel speed signal relative to other wheel speed signals is detected. If the deviation exceeds the set deviation threshold, the wheel speed sensor signal corresponding to the wheel speed signal is deemed invalid.

7. The independent redundant wheel speed processing system according to claim 1, characterized in that: The system includes: Two MCUs, namely a master MCU and a slave MCU, and output ends of four wheel speed signal processing units are connected to the master MCU and the slave MCU respectively; The master MCU and the slave MCU calculate the wheel speed signal of the corresponding wheel speed sensor based on the effective wheel speed pulse signal output by the wheel speed signal verification module.

8. The independent redundant wheel speed processing system as claimed in claim 7, characterized in that: The slave MCU will calculate the wheel speed signal of the corresponding wheel speed sensor based on the effective wheel speed pulse signal and send it to the master MCU; if the wheel speed signals calculated by the master MCU and the slave MCU are the same, it is determined that the master MCU has no fault.

9. An independent redundant wheel speed processing method based on the independent redundant wheel speed processing system according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: S1. Collect high-side voltage signals of four wheel speed sensors and output signals of the acquisition circuit, detect whether the wheel speed sensor has a high-side drive fault based on the high-side voltage signal, and detect whether the acquisition circuit has a low-side drive fault based on the output signal of the acquisition circuit; S2. If there is a high-side drive fault and / or a low-side drive fault, the corresponding wheel speed sensor is determined to be faulty. For the wheel speed sensor that does not have a high-side drive fault and a low-side drive fault, step S3 is executed; S3, detecting whether the wheel speed information output by the wheel speed sensor is valid, if the detection result is yes, proceeding to step S4, if the detection result is no, determining that the corresponding wheel speed sensor state and signal failure; S4. MCU verifies the valid wheel speed information, detects the failed wheel speed signal, and determines that the wheel speed sensor corresponding to the failed wheel speed signal is faulty.

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