Redundant steer-by-wire control method and control system for a vehicle

Abstract

The present application relates to the field of steering control technology, and specifically to a redundant wire-controlled steering control method and control system for a vehicle, specifically comprising: obtaining a real steering interval through steering wheel angle data; calculating the interference degree of the steering wheel angle based on the difference in steering wheel angles in different intervals, and constructing the steering correlation of each steering process in combination with the correlation between various types of steering data and the wheel speed characteristics during vehicle rotation; analyzing the communication status between the main and sub-ECUs, constructing a communication influencing factor, and calculating the fault factor of the main ECU in combination with the difference in the steering correlation and the corresponding data difference between the main and sub-ECUs, performing vehicle condition analysis based on the fault factor, and then performing vehicle steering control; reducing the probability of misjudgment and missed judgment in the status detection of the main ECU, improving the accuracy and efficiency of fault judgment, and thereby improving the precision and efficiency of the redundant wire-controlled steering control of the vehicle.

Description

Technical Field

[0001] The present application relates to the field of steering control technology, and in particular to a redundant wire-controlled steering control method and control system for a vehicle. Background Art

[0002] Redundant steer-by-wire control systems are a core technology in modern vehicles, particularly advanced driver assistance systems (ADAS) and autonomous vehicles (AVs), designed to provide exceptional safety and availability. This system relies on a multi-redundancy design to ensure that even if one or more components fail, the steering system maintains basic or full functionality, preventing vehicle loss of control.

[0003] Traditional redundant steer-by-wire systems rely on heartbeat signals or single data comparisons to determine main ECU faults. These systems are susceptible to environmental influences such as sensor noise and electromagnetic interference, which can lead to misjudgments or missed detections in the main ECU's status detection, thereby affecting the accuracy and efficiency of redundant steer-by-wire control. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of this application is to provide a redundant steer-by-wire control method and control system for a vehicle. The technical solutions adopted are as follows:

[0005] In a first aspect, an embodiment of the present application provides a redundant steer-by-wire control method for a vehicle, the method comprising the following steps:

[0006] Obtain torque, steering wheel angle, left wheel speed, right wheel speed, and yaw rate at each moment received by the ECU in the car. The ECU in the car includes a main ECU and a backup ECU.

[0007] Based on the zero point of the steering wheel angle data received by the main ECU, each steering process is divided; the torque sequence and angle sequence of each ECU in each steering process are obtained; based on the rate of change of the steering wheel angle at each moment and the difference between the angle sequences of different steering processes, the interference degree of the steering wheel angle in each steering process of each ECU is constructed;

[0008] A wheel speed difference sequence for the steering process is constructed based on the difference between the left wheel speed and the right wheel speed at each moment; characteristic parameters of each steering process for each ECU are determined based on the yaw angular velocity and steering wheel angle at each moment, combined with the vehicle speed; and steering correlations for each steering process for each ECU are constructed based on the correlation between the angle sequence, the wheel speed difference sequence, and the torque sequence, combined with the characteristic parameters and the interference degree.

[0009] determining a communication impact factor between the master ECU and the backup ECU based on a time length between two adjacent heartbeat signals received by the backup ECU; calculating a failure factor of the master ECU in each steering process based on a difference between the steering correlations of the master ECU and the backup ECU and a difference between the same type of data collected, in combination with the communication impact factor;

[0010] The vehicle steering control is performed based on the difference between the fault factor of the current steering process and the historical steering process.

[0011] In one embodiment, the process of obtaining the interference degree of the steering wheel angle during each steering process of each ECU is as follows:

[0012] For the data currently received by the ECU, the absolute value of the difference between each steering wheel angle data point and the steering wheel angle data point at the next moment is calculated as the angle change rate of each steering wheel angle data point;

[0013] Based on the difference between the angle change rates of two adjacent steering wheel angle data points and the metric distance between each steering process and the angle sequence of the Q-th steering process, the interference degree of the steering wheel angle data in the Q-th steering process is calculated, where Q is the sequence number of the steering process.

[0014] In one embodiment, the interference degree is expressed as:

[0015] , where is the interference degree of the steering wheel angle during the Q-th steering process; N is the number of steering wheel angle data points during the Q-th steering process; 、 are the steering angle change rates of the nth and n+1th steering wheel angle data points during the Qth steering process respectively; A represents the number of steering processes of the vehicle; It represents the DTW distance between the turning angle sequences of the a-th turning process and the Q-th turning process.

[0016] In one embodiment, the process of obtaining the wheel speed difference sequence during the steering process is as follows:

[0017] For the current steering process of the current ECU, the absolute value of the difference between the wheel speeds of the left wheel speed sequence and the right wheel speed sequence at the same time point in the steering process is calculated and recorded as the wheel speed difference. The sequence composed of all the wheel speed differences in the steering process is recorded as the wheel speed difference sequence of the steering process.

[0018] In one embodiment, the process of acquiring the characteristic parameters of each steering process of each ECU is as follows:

[0019] For the Qth steering process of the current ECU, the characteristic parameters of the Qth steering process are recorded as , The expression is:

[0020] , where N is the number of steering wheel angle data points during the Q-th steering process; is the yaw angular velocity at the nth acquisition moment during the Qth turning process, is the steering wheel angle at the nth acquisition moment during the Qth steering process; is the average vehicle speed during the Q-th turning process; is the preset vehicle speed threshold.

[0021] In one embodiment, the process of obtaining the steering relevance of each steering process of each ECU is as follows:

[0022] For the current steering process of the current ECU, the Pearson correlation coefficient between the steering angle sequence and the wheel speed difference sequence during the steering process is calculated, which is recorded as the first correlation; the Pearson correlation coefficient between the steering angle sequence and the torque sequence after the rightward translation t time is calculated, which is recorded as the second correlation, where time t is the difference between the acquisition time of the maximum torque in the torque sequence and the maximum steering wheel angle in the steering angle sequence; the product of the first correlation, the second correlation and the characteristic parameter is calculated, and the ratio of the product of the steering process to the interference degree is used as the steering correlation of the steering process.

[0023] In one embodiment, the process of obtaining the communication impact factor between the master ECU and the backup ECU is as follows:

[0024] Obtain the time length between two consecutive heartbeat signals received by the backup ECU, make statistics on all the time lengths, and take the time length with the highest frequency as the cycle length; record the time interval between the most recent heartbeat signal received and the last received as the characteristic time length; divide the difference between the characteristic time length and the cycle length by the cycle length, and the result obtained is used as the communication influencing factor between the main ECU and the backup ECU.

[0025] In one embodiment, the expression of the failure factor of the main ECU in each steering process is:

[0026]

[0027] Where, is the failure factor of the main ECU during the Qth steering process; 、 are the steering relevance of the steering data received by the main ECU and the backup ECU during the Qth steering process; Indicates the number of types of data collected; is the number of data points of the i-th category data during the Q-th steering process; 、 are the data values ​​of the nth data in the i-th type of data received by the main ECU and the backup ECU during the Q-th steering process; H represents the communication impact factor between the main ECU and the backup ECU.

[0028] In one embodiment, the vehicle steering control is performed based on the difference between the fault factors of the current steering process and the historical steering process, specifically:

[0029] The average fault factor of the main ECU in all historical steering processes is used as the fault threshold. If the fault factor of the main ECU in the current steering process is greater than or equal to the fault threshold, it is determined that the main ECU has failed and the backup ECU takes over the vehicle's steering control.

[0030] In a second aspect, an embodiment of the present application also provides a redundant steer-by-wire control system for a vehicle, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor implements the steps of any one of the above methods when executing the computer program.

[0031] The embodiments of the present application have at least the following beneficial effects:

[0032] This application detects the zero point in the steering wheel angle data to accurately separate the real steering interval and the interference interval, and eliminates invalid data interference; quantifies the impact of environmental interference through a steering wheel angle interference model, and constructs the steering correlation of each steering process based on the correlation characteristics between various steering data during normal vehicle steering and the wheel speed characteristics during vehicle rotation, thereby improving the robustness of the fault detection logic to random noise and transient interference, and being able to more reliably identify anomalies that truly deviate from normal physical behavior; and calculates the fault factor of the main ECU in each steering process through the heterogeneous channel data received by the backup ECU, combined with the dynamic weighting of the communication influencing factor, completes data verification and the construction of the fault factor index, and realizes a detailed and comprehensive evaluation of the main ECU status. The vehicle steering control is performed based on the difference between the fault factors of the current steering process and the historical steering process, thereby improving the accuracy and efficiency of fault judgment, thereby improving the accuracy and efficiency of the vehicle's redundant wire-controlled steering control. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present application or the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0034] Figure 1 A flowchart of a redundant steer-by-wire control method for a vehicle provided in one embodiment of the present application;

[0035] Figure 2 Schematic diagram of the interference degree acquisition process. DETAILED DESCRIPTION

[0036] To further illustrate the technical means and effectiveness of this application to achieve the intended invention objectives, the following, in conjunction with the accompanying drawings and preferred embodiments, describes in detail the specific implementation, structure, features, and effectiveness of a redundant steer-by-wire control method and control system for a vehicle proposed in this application. In the following description, different references to "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0037] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0038] The following describes in detail a redundant steer-by-wire control method and control system for a vehicle provided by the present application with reference to the accompanying drawings.

[0039] See also Figure 1 , which shows a flowchart of a redundant steer-by-wire control method for a vehicle provided by one embodiment of the present application, the method comprising the following steps:

[0040] Step S1, obtaining torque, steering wheel angle, left wheel speed, right wheel speed and yaw rate at each moment received by the ECU in the car, where the ECU in the car includes a main ECU and a backup ECU.

[0041] A vehicle includes two physically independent, functionally identical steering control units: a primary ECU (electronic control unit) and a backup ECU. When the driver turns the steering wheel or the autonomous driving system issues a steering command, both the primary and backup ECUs receive steering wheel sensor signals and vehicle status signals. The primary ECU calculates the target steering angle / torque and controls the steering actuator. The steering wheel sensor signals include torque data collected by the steering torque sensor and steering wheel angle data collected by the steering angle sensor. The vehicle status signals include left and right wheel speed data collected by the wheel speed sensors, as well as yaw rate data collected by the yaw rate sensor. Each sensor has multiple channels, and the data collection frequency for each sensor is consistent. All of this collected data is used as vehicle steering data.

[0042] The backup ECU also receives the same signal and performs the same calculations as the primary ECU, comparing the results with those from the primary ECU. The backup ECU monitors the primary ECU's status using the comparison results and the heartbeat signal from the primary ECU. The signals received by the backup and primary ECUs are from the same sensor, but on different channels.

[0043] The two ECUs exchange critical status information in real time via a highly reliable dedicated communication link, which can be CAN FD (CAN with Flexible Data rate), FlexRay, or Ethernet.

[0044] Step S2: dividing the steering wheel angle data received by the main ECU based on the zero point to obtain each steering process; obtaining the torque sequence and angle sequence of each ECU in each steering process; and constructing the interference degree of the steering wheel angle in each steering process of each ECU based on the rate of change of the steering wheel angle at each moment and the difference between the angle sequences of different steering processes.

[0045] (1) For the various sensor signal data received by the main ECU, this application first preliminarily classifies the various sensor data according to the data change characteristics of the steering wheel angle sensor when the vehicle turns, and divides the collected sensor data into multiple steering processes, specifically:

[0046] The steering wheel angle sensor collects the angle of the steering wheel, that is, the rotation angle calculated from the neutral position of the steering wheel. During each vehicle steering process, the rotation angle collected by the steering wheel angle sensor should start from 0 degrees. When the steering is completed, the steering wheel of the vehicle will return to the center, and the rotation angle will return to 0 degrees, completing one vehicle steering.

[0047] Therefore, based on this feature, first, the steering wheel angle data received by the main ECU is obtained and the zero point is marked. The zero point is: if the moment The steering wheel angle data is 0, and the moment If the steering wheel angle data of at least one of the two adjacent moments before and after is not 0, then the moment The steering wheel angle data point is marked as zero;

[0048] The time interval between two adjacent zero points is then recorded as the candidate turning interval. The average value of all steering wheel angle data within the candidate turning interval is calculated. If the average value is greater than or equal to the average value of all steering wheel angle data collected by the angle sensor, the candidate turning interval is considered the actual turning interval. Otherwise, it is considered the interference turning interval, which is a turning interval that is falsely detected due to slight shaking of the steering wheel caused by interference. Therefore, this application only analyzes the actual turning interval.

[0049] Following the above steps, multiple steering intervals captured by the steering wheel angle sensor are obtained. Each steering interval corresponds to a single vehicle steering process. Taking all steering data received by the main ECU as an example, the time series of all steering wheel angle data within each steering interval is denoted as the steering angle sequence, the time series of torque data is denoted as the torque sequence, the time series of left wheel speed data is denoted as the left wheel speed sequence, the time series of right wheel speed data is denoted as the right wheel speed sequence, and the time series of yaw rate data is denoted as the yaw rate sequence. Since the data collection frequency of each sensor is consistent, all sequences within each steering interval have the same collection time and are of equal length.

[0050] (2) Analyze the vehicle's steering process. Since the vehicle is easily affected by external interference during driving, such as electromagnetic interference, mechanical vibration, temperature changes, and sensor noise, the data collected by the sensor is not accurate. According to the steering characteristics of the vehicle during steering, the steering wheel angle data is strongly correlated with the other data. Therefore, this application further analyzes the steering wheel angle data.

[0051] When a vehicle is turning, the steering wheel angle data usually increases to a certain amplitude, remains stable for a certain period of time, and then decays to 0. The change in the steering wheel angle data during each turn shows this trend. Therefore, the following calculation is performed:

[0052] First, the steering angle change rate of each steering wheel angle data point during each turn is obtained. The steering angle change rate is the absolute value of the difference between the steering wheel angle value of each steering wheel angle data point and the steering wheel angle value of the steering wheel angle data point at the next moment. The greater the steering angle change rate, the more drastic the local change in the steering wheel angle, and the more likely it is to be interfered with.

[0053] Then, taking the Qth steering process as an example, the interference degree of the steering wheel angle data in each steering process is constructed based on the consistency of the change trend of the steering wheel angle data in different steering processes and the local change amplitude of the data. The expression is:

[0054] , where is the interference degree of the steering wheel angle data during the Q-th steering process; N is the number of steering wheel angle data points during the Q-th steering process; 、 are the steering angle change rates of the nth and n+1th steering wheel angle data points during the Qth steering process, respectively; A represents the number of steering processes of the vehicle, that is, the number of steering intervals; It represents the DTW distance between the corner sequence in the a-th turning process and the corner sequence in the Q-th turning process. The calculation of the DTW distance is a well-known technology and the specific process will not be repeated here.

[0055] It should be noted that for the measurement distance between the corner sequences of different steering processes, this application only provides a distance measurement method. There are many existing distance measurement methods. Implementers can also use other distance measurement algorithms to obtain the measurement distance between the corner sequences of different steering processes. This application does not make specific restrictions.

[0056] The larger the DTW distance, the less consistent the change trend of the steering wheel angle data is and the greater the interference is. The larger it is, the more the overall change trend of the steering wheel angle data during the steering process conforms to the steering characteristics, but the local steering data changes do not conform to the change characteristics of the angle data, and the greater the interference to the steering wheel angle data during the steering process; conversely, the more the overall change trend of the steering wheel angle data during the steering process conforms to the steering characteristics, and the more the local steering data changes conform to the change characteristics of the angle data, the smaller the interference to the steering wheel angle data during the steering process.

[0057] Step S3: constructing a wheel speed difference sequence for the steering process based on the difference between the left wheel speed and the right wheel speed at each moment; determining characteristic parameters of each steering process for each ECU based on the yaw angular velocity and steering wheel angle at each moment, combined with the vehicle speed; and constructing a steering correlation for each steering process for each ECU based on the correlation between the angle sequence, the wheel speed difference sequence, and the torque sequence, combined with the characteristic parameters and the interference degree.

[0058] According to the above steps, the interference degree of the steering wheel angle data is obtained. The interference degree reflects the degree of environmental interference to the steering wheel angle data during the steering process. In this application, it is used as the weight for the analysis of the correlation characteristics of the steering wheel angle data and other data, thereby improving the accuracy of the steering correlation index. According to the analysis of the vehicle steering process, when the vehicle driver wants to turn, he must first apply torque to the steering wheel. The greater the torque, the faster the steering, and the smaller the torque, the slower the steering. That is, there is a strong correlation between the data collected by the torque sensor and the rate of change of the steering wheel angle, and the change in torque leads the change in the angle. The steering wheel angle is proportional to the yaw rate generated by the vehicle, and the proportional coefficient is affected by the vehicle speed. At low speeds, large angles correspond to small yaw rates, and at high speeds, small angles correspond to large yaw rates. The steering wheel angle determines the difference in left and right wheel speeds when the vehicle is turning. That is, the larger the steering wheel angle data, the greater the corresponding wheel speed difference, and the two are strongly correlated. Therefore, the following calculation is performed:

[0059] First, the wheel speed difference sequence for each steering process is obtained. The wheel speed difference sequence is obtained by calculating the absolute value of the difference between the wheel speeds of the left wheel speed sequence and the right wheel speed sequence at the same time point during the steering process, recording it as the wheel speed difference. The sequence composed of the wheel speed differences at all moments in the steering process is arranged in ascending chronological order and recorded as the wheel speed difference sequence for the steering process.

[0060] Taking the Qth steering process as an example, the steering correlation of each vehicle steering process is constructed based on the change characteristics between the steering wheel angle data and other types of data during the vehicle steering process. The expression is:

[0061]

[0062]

[0063] Where, is the steering relevance of the Q-th steering process; is the Pearson correlation coefficient between the steering angle sequence and the wheel speed difference sequence during the Qth steering process, denoted as the first correlation; is the Pearson correlation coefficient between the steering angle sequence during the Q-th steering process and the torque sequence after a rightward translation of t time, denoted as the second correlation, where time t is the difference between the acquisition time of the data point with the maximum torque value in the torque sequence and the acquisition time of the data point with the maximum steering wheel angle value in the steering angle sequence; is the interference degree of the steering wheel angle data during the Q-th steering process;

[0064] is the characteristic parameter of the Q-th steering process; N is the number of steering wheel angle data points in the Q-th steering process, that is, the number of acquisition moments in the steering process; is the yaw angular velocity at the nth acquisition moment during the Qth turning process, is the steering wheel angle at the nth acquisition moment during the Qth steering process; is the average vehicle speed during the Q-th turning process; is a preset vehicle speed threshold. Preferably, in the embodiment of the present application, the vehicle speed threshold is set to As other embodiments of the present application, the implementer may adjust the value according to the actual situation. If the Pearson correlation coefficient is negative, it is regarded as 0 for calculation.

[0065] characteristic parameters The larger the value, the more consistent the changes in the steering angle data and yaw rate are with the characteristics of small yaw rate at low speed and large yaw rate at high speed when the vehicle is turning, and the greater the steering correlation is. The larger the two Pearson correlation coefficients are, the greater the correlation between the steering wheel angle data and the wheel speed difference data and torque data is, and the more consistent they are with the characteristics of vehicle steering, and the greater the steering correlation is. The smaller the interference is, the less the steering process is affected by the environment, and the greater the weight of the steering process is.

[0066] The greater the steering correlation, the more consistent the changes in various steering-related data during the steering process are with the vehicle's steering characteristics, and the less likely the vehicle's main ECU is to malfunction. The smaller the steering correlation, the less consistent the changes in various steering-related data are with the vehicle's steering characteristics, and the more likely the vehicle's main ECU is to malfunction.

[0067] Step S4, determining the communication impact factor between the main ECU and the backup ECU based on the time length between two adjacent heartbeat signals received by the backup ECU; calculating the failure factor of the main ECU in each steering process based on the difference between the steering correlations of the main ECU and the backup ECU and the difference between the collected data of the same type, combined with the communication impact factor.

[0068] According to the above steps, the steering correlation between the steering data received by the vehicle main ECU during the steering process is obtained. At the same time, based on the steering data received by the backup ECU, the steering correlation of each steering process of the backup ECU is calculated using the same acquisition method as that of the steering correlation of each steering process of the main ECU, wherein each steering process of the backup ECU is the same as that of the main ECU.

[0069] The above steps can be used to obtain the steering relevance of the steering data received by the primary ECU for each steering process. In a redundant steer-by-wire system, the primary ECU will send the received steering data and the steering relevance of the steering data to the backup ECU, and will also transmit a corresponding heartbeat signal. The backup ECU will further analyze the signals transmitted by the primary ECU to complete the fault detection and judgment of the primary ECU. The specific process is as follows:

[0070] In a redundant steer-by-wire system, the heartbeat signal is a periodic signal sent by the primary ECU to the backup ECU to confirm its status. This signal verifies that the primary ECU is functioning properly. It is essentially a pre-formatted communication message containing key status information and a verification mechanism.

[0071] Therefore, for the backup ECU, this application first obtains each received heartbeat signal. The difference between the heartbeat signal reception interval and the cycle length is used to preliminarily reflect the current status and communication quality of the main ECU. The time length between each heartbeat signal received by the backup ECU and the next heartbeat signal is obtained, and the obtained time lengths are statistically analyzed. Since communication is easily interfered with by external factors, there may be multiple obtained time lengths. The time length with the highest frequency is used as the cycle length. The time interval between the most recent heartbeat signal received by the backup ECU and the previous heartbeat signal received can be obtained and recorded as the characteristic time length. The difference between the characteristic time length and the cycle length is divided by the cycle length, and this ratio is used as the communication impact factor H between the main ECU and the backup ECU. The larger the difference, the greater the delay of the heartbeat signal during communication, the worse the communication quality, and the greater the risk of loss or tampering of the transmitted signal. That is, the corresponding weight is smaller when the signal is judged. It should be noted that when the communication quality is too poor, the communication between the main ECU and the backup ECU will fail, and the data of the main ECU cannot be transmitted to the backup ECU for verification. At this time, the backup ECU will actively take over the steering control of the main ECU.

[0072] According to the above steps, the backup ECU will also receive the above steering-related data. The difference is that the data received by the backup ECU comes from another channel of the sensor. Therefore, in this application, the steering data of the main ECU is verified by the data from different channels of the sensor received by the backup ECU, and then the failure factor of the main ECU is constructed. The expression is:

[0073]

[0074] Where, is the failure factor of the main ECU during the Qth steering process; 、 are the steering relevance of the steering data received by the main ECU and the backup ECU during the Qth steering process; Indicates the number of types of data collected. In the embodiment of the present application, The value of 4 is the data collected by the steering wheel torque sensor, steering wheel angle sensor, wheel speed sensor and yaw rate sensor; is the number of data points of the i-th category data during the Q-th steering process; 、 are the data values ​​of the nth data in the i-th type of data received by the main ECU and the backup ECU during the Q-th steering process; H represents the communication impact factor between the main ECU and the backup ECU.

[0075] The larger the fault factor, the greater the possibility of the main ECU failing, and the smaller the fault factor, the smaller the possibility of the main ECU failing.

[0076] Step S5 , performing vehicle steering control based on the difference between the fault factors of the current steering process and the historical steering process.

[0077] Following the above steps, the failure factor of the master ECU in the vehicle's redundant steer-by-wire control system is acquired. The corresponding master ECU failure factor is then obtained for each steering process. The average failure factor of the master ECU for all historical steering processes is calculated and used as the failure threshold. If the failure factor of the master ECU during the current steering process is greater than or equal to the failure threshold, the master ECU is deemed to have failed, and the backup ECU takes over steering control of the vehicle. Otherwise, the master ECU retains control of the vehicle's steering.

[0078] The schematic diagram of the interference degree acquisition process is as follows: Figure 2 shown.

[0079] Based on the same inventive concept as the above-mentioned method, an embodiment of the present application also provides a redundant steering-by-wire control system for a vehicle, comprising a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the steps of any one of the above-mentioned redundant steering-by-wire control methods for a vehicle are implemented.

[0080] In summary, the embodiment of the present application provides a redundant steering-by-wire control method for a vehicle, which accurately separates the real steering interval from the interference interval by detecting the zero point in the steering wheel angle data, and eliminates invalid data interference; quantifies the impact of environmental interference through a steering wheel angle interference model, and constructs the steering correlation of each steering process based on the correlation characteristics between various types of steering data during the normal steering process of the vehicle and the wheel speed characteristics during the vehicle rotation process, thereby improving the robustness of the fault detection logic to random noise and transient interference, and can more reliably identify anomalies that truly deviate from normal physical behavior; and calculates the fault factor of the main ECU in each steering process through the heterogeneous channel data received by the backup ECU, combined with the dynamic weighting of the communication influencing factor, completes data verification and the construction of the fault factor index, and realizes a detailed and comprehensive evaluation of the main ECU status. The vehicle steering control is performed based on the difference between the fault factors of the current steering process and the historical steering process, thereby improving the accuracy and efficiency of fault judgment, thereby improving the accuracy and efficiency of the vehicle's redundant steering-by-wire control.

[0081] It should be noted that the order in which the embodiments of the present application are presented is for illustrative purposes only and does not necessarily represent the superiority or inferiority of the embodiments. Furthermore, the above descriptions are of specific embodiments of the present application. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order or sequential sequence shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0082] The various embodiments in this application are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0083] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A redundant steer-by-wire control method for a vehicle, characterized in that: The method comprises the following steps: Obtain torque, steering wheel angle, left wheel speed, right wheel speed, and yaw rate at each moment received by the ECU in the car. The ECU in the car includes a main ECU and a backup ECU. Based on the zero point of the steering wheel angle data received by the main ECU, each steering process is divided; the torque sequence and angle sequence of each ECU in each steering process are obtained; based on the rate of change of the steering wheel angle at each moment and the difference between the angle sequences of different steering processes, the interference degree of the steering wheel angle in each steering process of each ECU is constructed; A wheel speed difference sequence for the steering process is constructed based on the difference between the left wheel speed and the right wheel speed at each moment; characteristic parameters of each steering process for each ECU are determined based on the yaw angular velocity and steering wheel angle at each moment, combined with the vehicle speed; and steering correlations for each steering process for each ECU are constructed based on the correlation between the angle sequence, the wheel speed difference sequence, and the torque sequence, combined with the characteristic parameters and the interference degree. determining a communication impact factor between the master ECU and the backup ECU based on a time length between two adjacent heartbeat signals received by the backup ECU; calculating a failure factor of the master ECU in each steering process based on a difference between the steering correlations of the master ECU and the backup ECU and a difference between the same type of data collected, in combination with the communication impact factor; The vehicle steering control is performed based on the difference between the fault factor of the current steering process and the historical steering process.

2. The redundant steer-by-wire control method for a vehicle according to claim 1, wherein: The process of obtaining the interference degree of the steering wheel angle during each steering process of each ECU is as follows: For the data currently received by the ECU, the absolute value of the difference between each steering wheel angle data point and the steering wheel angle data point at the next moment is calculated as the angle change rate of each steering wheel angle data point; Based on the difference between the angle change rates of two adjacent steering wheel angle data points and the metric distance between each steering process and the angle sequence of the Q-th steering process, the interference degree of the steering wheel angle data in the Q-th steering process is calculated, where Q is the sequence number of the steering process.

3. The redundant steer-by-wire control method for a vehicle according to claim 2, wherein: The expression of the interference degree is: , where is the interference degree of the steering wheel angle during the Q-th steering process; N is the number of steering wheel angle data points during the Q-th steering process; 、 are the steering angle change rates of the nth and n+1th steering wheel angle data points during the Qth steering process respectively; A represents the number of steering processes of the vehicle; It represents the DTW distance between the turning angle sequences of the a-th turning process and the Q-th turning process.

4. The redundant steer-by-wire control method for a vehicle according to claim 1, wherein: The process of obtaining the wheel speed difference sequence during the steering process is as follows: For the current steering process of the current ECU, the absolute value of the difference between the wheel speeds of the left wheel speed sequence and the right wheel speed sequence at the same time point in the steering process is calculated and recorded as the wheel speed difference. The sequence composed of all the wheel speed differences in the steering process is recorded as the wheel speed difference sequence of the steering process.

5. The redundant steer-by-wire control method for a vehicle according to claim 1, wherein: The process of acquiring the characteristic parameters of each steering process of each ECU is as follows: For the Qth steering process of the current ECU, the characteristic parameters of the Qth steering process are recorded as , The expression is: , where N is the number of steering wheel angle data points during the Q-th steering process; is the yaw angular velocity at the nth acquisition moment during the Qth turning process, is the steering wheel angle at the nth acquisition moment during the Qth steering process; is the average vehicle speed during the Q-th turning process; is the preset vehicle speed threshold.

6. The redundant steer-by-wire control method for a vehicle according to claim 1, wherein: The process of obtaining the steering relevance of each steering process of each ECU is as follows: For the current steering process of the current ECU, the Pearson correlation coefficient between the steering angle sequence and the wheel speed difference sequence during the steering process is calculated and recorded as the first correlation; Calculate the Pearson correlation coefficient between the steering angle sequence during the steering process and the torque sequence after the rightward translation t time, which is recorded as the second correlation, where time t is the difference between the acquisition time of the maximum torque in the torque sequence and the maximum steering wheel angle in the steering angle sequence; calculate the product of the first correlation, the second correlation and the characteristic parameter, and use the ratio of the product of the steering process to the interference degree as the steering correlation of the steering process.

7. The redundant steer-by-wire control method for a vehicle according to claim 1, wherein: The acquisition process of the communication impact factor between the main ECU and the backup ECU is as follows: Obtain the time length between two consecutive heartbeat signals received by the standby ECU, collect statistics on all the time lengths, and take the time length with the highest frequency as the cycle length; record the time interval between the most recent heartbeat signal received and the last received heartbeat signal as the characteristic time length; The difference between the characteristic time length and the cycle length is divided by the cycle length, and the result obtained is used as the communication impact factor between the main ECU and the backup ECU.

8. The redundant steer-by-wire control method for a vehicle according to claim 1, wherein: The expression of the failure factor of the main ECU in each steering process is: Where, is the failure factor of the main ECU during the Qth steering process; 、 are the steering relevance of the steering data received by the main ECU and the backup ECU during the Qth steering process; Indicates the number of types of data collected; is the number of data points of the i-th category data during the Q-th steering process; 、 are the data values ​​of the nth data in the i-th type of data received by the main ECU and the backup ECU during the Q-th steering process; H represents the communication impact factor between the main ECU and the backup ECU.

9. The redundant steer-by-wire control method for a vehicle according to claim 1, wherein: The vehicle steering control is performed based on the difference between the fault factors of the current steering process and the historical steering process, specifically: The average fault factor of the main ECU in all historical steering processes is used as the fault threshold. If the fault factor of the main ECU in the current steering process is greater than or equal to the fault threshold, it is determined that the main ECU has failed and the backup ECU takes over the vehicle's steering control.

10. A redundant steer-by-wire control system for a vehicle, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 9 are implemented.

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