Steering-by-wire system diagnosis method and device, and automatic driving domain controller

Abstract

The embodiment of the present disclosure belongs to the technical field of intelligent driving, and provides a steer-by-wire system diagnosis method and device and an automatic driving domain controller. The method comprises the following steps: sending a first target steering wheel angle to a steer-by-wire system, obtaining a first actual steering wheel angle responded by the steer-by-wire system; calculating a first theoretical steering wheel angle according to the first target steering wheel angle and a steer-by-wire system model established in advance; calculating a first residual error between the first actual steering wheel angle and the first theoretical steering wheel angle; judging whether a first duration, during which the first residual error is greater than a residual error threshold, is greater than a time threshold; and if yes, determining that the steering performance of the steer-by-wire system is attenuated. The method of the embodiment of the present disclosure can timely find out whether the steering performance of the steer-by-wire system is attenuated, and thus can improve the safety performance of an unmanned vehicle loaded with the steer-by-wire system and reduce the operation cost of the unmanned vehicle.

Description

Technical Field

[0001] This disclosure belongs to the field of intelligent driving technology, specifically relating to a diagnostic method and device for a steer-by-wire system and an autonomous driving domain controller. Background Technology

[0002] A steering-by-wire (SBW) system mainly consists of a steering wheel module, a steering gear module, and an Electronic Control Unit (ECU). In an SBW system, the driver transmits steering signals to the ECU via sensors on the steering wheel. The ECU analyzes and processes the collected signals and then sends control signals to the steering motor, thereby controlling the torque required for steering and turning the wheels to achieve the driver's steering intention. Simultaneously, sensors on the steering wheels feed back the wheel steering angle and steering acceleration to the ECU, which then sends signals to the steering wheel return torque motor to generate the steering wheel return torque, providing the driver with the necessary sensor information.

[0003] Mining environments are characterized by high levels of dust, vibration, and impact, which affect the performance of the steer-by-wire system in unmanned mining trucks. Degraded steering system performance leads to decreased lateral tracking accuracy, potentially causing accidents at high speeds, such as approaching or colliding with retaining walls. Currently, mainstream domestic unmanned mining truck steer-by-wire fault diagnosis systems are incomplete, only diagnosing failure modes of some key components—essentially functional fault diagnosis. When the entire system experiences performance degradation, it may not be detected promptly, allowing the fault to worsen and potentially damage more components, increasing maintenance costs and time, and reducing the operational economics of unmanned mining trucks. Summary of the Invention

[0004] This disclosure aims to at least solve one of the technical problems existing in the prior art, and to provide a diagnostic method and device for a steer-by-wire system and an autonomous driving domain controller.

[0005] One aspect of this disclosure provides a diagnostic method for a steer-by-wire system, the method comprising:

[0006] The first target steering wheel angle is sent to the steer-by-wire system to obtain the first actual steering wheel angle in response to the steer-by-wire system.

[0007] Based on the first target steering wheel angle and the pre-established steer-by-wire system model, the first theoretical steering wheel angle is calculated.

[0008] Calculate the first residual between the first actual steering wheel angle and the first theoretical steering wheel angle;

[0009] Determine whether the first duration for which the first residual is greater than the residual threshold is greater than the time threshold; if so, determine that the steering performance of the steer-by-wire system has degraded.

[0010] Optionally, the method further includes:

[0011] Timing is initiated when the first residual is greater than the residual threshold to generate the first duration.

[0012] Optionally, the first target steering wheel angle is generated by the autonomous driving domain controller.

[0013] Optionally, the steer-by-wire system model is established using the following steps:

[0014] A frequency sweep test was performed on the steer-by-wire system, and the frequency response curve of the steer-by-wire system was obtained based on the results of the frequency sweep test.

[0015] Based on the frequency response curve, the amplitude-frequency response characteristics of the steer-by-wire system are obtained;

[0016] Based on the amplitude-frequency response characteristics, the steer-by-wire system model is obtained.

[0017] Optionally, the steer-by-wire system model adopts a second-order transfer function model, as shown in equations (1) and (2) below:

[0018] (1)

[0019] (2)

[0020] Where M(z) is the transfer function, z is the z-transformation factor, a and b are both coefficients, c is a constant term, Y(z) is the z-transformation of the theoretical steering wheel angle, and U(z) is the z-transformation of the target steering wheel angle.

[0021] Optionally, the method further includes:

[0022] Based on the statistical results of the maximum speed response data of steer-by-wire for the same vehicle model, the residual threshold and the time threshold are determined.

[0023] Optionally, determining the residual threshold and the time threshold based on statistical results of the maximum speed response data of steer-by-wire for the same vehicle model includes:

[0024] The second target steering wheel angle is sent multiple times to the steer-by-wire system of at least one vehicle of the same model to obtain the second actual steering wheel angle responded by the steer-by-wire system; wherein, the second target steering wheel angle is the passive maximum required speed of the steer-by-wire system;

[0025] The second theoretical steering wheel angle is calculated based on the second target steering wheel angle and the steer-by-wire system model.

[0026] Calculate the second residuals of each of the second actual steering wheel angles and the second theoretical steering wheel angles of the at least one vehicle, and calculate the mean and standard deviation of the second residuals of the at least one vehicle, and calculate the second duration of each of the second residuals of the at least one vehicle within a preset residual interval.

[0027] The maximum value of the mean of the second residuals of the at least one vehicle is used as the residual threshold, and the maximum value of the second duration is used as the time threshold.

[0028] In another aspect of this disclosure, a diagnostic device for a steer-by-wire system is provided, the device comprising:

[0029] The sending module is used to send the first target steering wheel angle to the steer-by-wire system and obtain the first actual steering wheel angle in response to the steer-by-wire system.

[0030] The calculation module is used to calculate the first theoretical steering wheel angle based on the first target steering wheel angle and the pre-established steer-by-wire system model;

[0031] The calculation module is also used to calculate the first residual between the first actual steering wheel angle and the first theoretical steering wheel angle;

[0032] The diagnostic module is used to determine whether the first duration for which the first residual is greater than the residual threshold is greater than the time threshold. If so, it determines that the steering performance of the steer-by-wire system has degraded.

[0033] In another aspect of this disclosure, an autonomous driving domain controller is provided, comprising:

[0034] The transmitting unit is used to send the first target steering wheel angle to the steer-by-wire system and obtain the first actual steering wheel angle responded by the steer-by-wire system.

[0035] The calculation unit is used to calculate the first theoretical steering wheel angle based on the first target steering wheel angle and the pre-established steer-by-wire system model;

[0036] The calculation unit is also used to calculate the first residual between the first actual steering wheel angle and the first theoretical steering wheel angle;

[0037] The diagnostic unit is used to determine whether the first duration for which the first residual is greater than the residual threshold is greater than the time threshold. If so, it determines that the steering performance of the steer-by-wire system has degraded.

[0038] In another aspect of this disclosure, an electronic device is provided, comprising:

[0039] One or more processors;

[0040] A storage unit for storing one or more programs that, when executed by one or more processors, enable the one or more processors to implement the method described above.

[0041] The steer-by-wire system diagnostic method and apparatus, and autonomous driving domain controller of this disclosure take the entire steer-by-wire system as the diagnostic object. By establishing a steer-by-wire system model of the entire steer-by-wire system, the theoretical steering wheel angle is obtained based on the input target steering wheel angle and the model. The steering performance of the steer-by-wire system is determined based on the theoretical steering wheel angle and the actual steering wheel angle of the steer-by-wire system. This allows for timely detection of whether the steering performance of the steer-by-wire system has deteriorated, thereby improving the safety performance of autonomous vehicles equipped with the steer-by-wire system and reducing the operating costs of autonomous vehicles. Attached Figure Description

[0042] Figure 1 This is a flowchart of one embodiment of the steer-by-wire system diagnostic method according to the present disclosure;

[0043] Figure 2 A schematic diagram illustrating the interaction between the autonomous driving domain controller and the steer-by-wire system for implementing the diagnostic method for the steer-by-wire system disclosed herein.

[0044] Figure 3 This is a schematic diagram of one embodiment of the steer-by-wire system diagnostic method according to the present disclosure;

[0045] Figure 4 This is a schematic diagram of the structure of a diagnostic device for a steer-by-wire system according to an embodiment of the present disclosure;

[0046] Figure 5 This is a schematic diagram of the structure of an embodiment of an autonomous driving domain controller according to the present disclosure;

[0047] Figure 6 A block diagram of one embodiment of an electronic device for performing the diagnostic method for the steer-by-wire system disclosed herein. Detailed Implementation

[0048] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] In this disclosure, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" and "second" may explicitly or implicitly include at least one of those features.

[0050] This disclosure provides a diagnostic method for a steer-by-wire system. Figure 1 A flowchart 100 of an embodiment of a steer-by-wire system diagnostic method according to the present disclosure is shown, the flowchart 100 including the following specific steps:

[0051] Step 110: Send the first target steering wheel angle to the steer-by-wire system to obtain the first actual steering wheel angle responded by the steer-by-wire system.

[0052] In some embodiments, the entity that sends the first target steering wheel angle to the steer-by-wire system and receives the first actual steering wheel angle in response from the steer-by-wire system is the autonomous driving domain controller. (See also...) Figure 2 , Figure 2 A schematic diagram illustrating the interaction between the autonomous driving domain controller and the steer-by-wire system in implementing the diagnostic method for the steer-by-wire system disclosed herein is shown. Figure 2 As shown, when it is necessary to control the steering of an unmanned vehicle equipped with a steer-by-wire system 220, the vehicle may be an unmanned mining truck, an unmanned car, etc. The autonomous driving domain controller 210 sends the required first target steering wheel angle to the steer-by-wire system 220. When the steer-by-wire system 220 receives the first target steering wheel angle, it will respond with a first actual steering wheel angle and return it to the autonomous driving domain controller 210, so that the autonomous driving domain controller 210 can perform subsequent operations based on the returned first actual steering wheel angle, such as continuing to send the next target steering wheel angle.

[0053] In some other embodiments, the entity that sends the first target steering wheel angle to the steer-by-wire system and obtains the first actual steering wheel angle in response from the steer-by-wire system is another controller with data transmission and processing capabilities, such as a central processing unit. This disclosure does not specifically limit this aspect.

[0054] Step 120: Calculate the first theoretical steering wheel angle based on the first target steering wheel angle and the pre-established steer-by-wire system model.

[0055] In some embodiments, the entity that executes the calculation of the first theoretical steering wheel angle based on the first target steering wheel angle and a pre-established steer-by-wire system model is the autonomous driving domain controller. For example... Figure 2As shown, the autonomous driving domain controller 210 calculates the first theoretical steering wheel angle based on the first target steering wheel angle previously issued to the steer-by-wire system 220 and the steer-by-wire system model. Of course, in some other embodiments, the main body executing step 120 is other controllers with data issuance and processing capabilities, such as central processing units, etc., and this disclosure does not specifically limit this.

[0056] In other embodiments, the steer-by-wire system model is trained using machine learning. For example, a training dataset of steer-by-wire systems from multiple vehicles of the same model is pre-acquired. This dataset includes the target steering wheel angle and the corresponding theoretical steering wheel angle. The target steering wheel angle is used as input, and the corresponding theoretical steering wheel angle is used as output to train the steer-by-wire system model, resulting in a trained model. It should be understood that to improve the prediction accuracy of the steer-by-wire system model, the number of training datasets should be sufficiently large, such as one thousand or ten thousand or more.

[0057] In some other embodiments, the steer-by-wire system model is established through a frequency sweep test method. For example, a frequency sweep test is performed on the steer-by-wire system, and the frequency response curve of the steer-by-wire system is obtained based on the test results. The amplitude-frequency response characteristics of the steer-by-wire system are then obtained based on the frequency response curve. Finally, the steer-by-wire system model is obtained based on the amplitude-frequency response characteristics.

[0058] As a specific example, the steer-by-wire system model is a function transfer model with a second-order system, and the steer-by-wire system model is shown in equation (1) below:

[0059] (1)

[0060] (2)

[0061] Where M(z) is the transfer function, z is the z-transformation factor, a and b are both coefficients, c is a constant term, Y(z) is the z-transformation of the theoretical steering wheel angle, and U(z) is the z-transformation of the target steering wheel angle.

[0062] It should be noted that, in addition to the second-order system transfer function model mentioned above, the steer-by-wire system model can also use other transfer function models, such as third-order or higher-order transfer function models. This embodiment does not limit this.

[0063] Step 130: Calculate the first residual between the first actual steering wheel angle and the first theoretical steering wheel angle.

[0064] In some embodiments, the entity that performs the calculation of the first residual between the first actual steering wheel angle and the first theoretical steering wheel angle is the aforementioned autonomous driving domain controller. For example... Figure 2 As shown, the autonomous driving domain controller 210 calculates the first residual between the first actual steering wheel angle obtained from the steer-by-wire system 220 and the first theoretical steering wheel angle calculated, so as to determine the steering performance of the steer-by-wire system 220 based on the first residual.

[0065] Step 140: Determine whether the first duration for which the first residual is greater than the residual threshold is greater than the time threshold. If so, determine that the steering performance of the steer-by-wire system has degraded.

[0066] Specifically, the residual threshold is the maximum residual value that allows the first actual steering wheel angle to deviate from the first theoretical steering wheel angle. In other words, when the residual between the first actual steering wheel angle and the first theoretical steering wheel angle is less than the residual threshold, the steering performance of the steer-by-wire system meets the requirements. Conversely, when the residual between the first actual steering wheel angle and the first theoretical steering wheel angle is greater than the residual threshold, the steering performance of the steer-by-wire system deteriorates, that is, the steering angle following performance decreases.

[0067] In some embodiments, when the first residual is greater than a residual threshold, it is determined that the steering performance of the steer-by-wire system may have degraded, that is, the following performance of the steer-by-wire system may have malfunctioned. To more accurately determine whether the steering performance of the steer-by-wire system has degraded, and to avoid misjudgments due to occasional factors, it is necessary to determine whether the first duration for which the first residual is greater than the residual threshold is greater than a time threshold. If so, the steering performance of the steer-by-wire system is directly determined to have degraded.

[0068] In some embodiments, the first duration is obtained as follows: timing begins when the first residual is greater than a residual threshold. During the timing process, if at any point the first residual falls below the residual threshold, the timing is reset to zero, and timing restarts the next time the first residual exceeds the residual threshold. When the timing exceeds a time threshold, it is determined that the steering performance of the steering system has degraded; this timing time is also the first duration of this embodiment.

[0069] In some embodiments, the residual threshold and time threshold are determined by those skilled in the art based on experience; for example, they may be determined by those skilled in the art based on historical experience data of steer-by-wire systems of the same vehicle model. In other embodiments, the residual threshold and time threshold are set by the manufacturer of the steer-by-wire system to ensure timely detection of steering performance degradation.

[0070] In some embodiments, the residual threshold and the time threshold are determined based on statistical results of the maximum speed response data of the steer-by-wire system for the same vehicle model. The determination method of the residual threshold and the time threshold will be explained in detail below.

[0071] The second target steering wheel angle is sent multiple times to the steer-by-wire system of at least one vehicle of the same model to obtain the second actual steering wheel angle in response to the steer-by-wire system; wherein, the second target steering wheel angle is the passive maximum required speed of the steer-by-wire system.

[0072] The second theoretical steering wheel angle is calculated based on the second target steering wheel angle and the steer-by-wire system model.

[0073] The second residuals of each of the second actual steering wheel angles and the second theoretical steering wheel angles of the at least one vehicle are calculated respectively, and the mean and standard deviation of the second residuals of the at least one vehicle are calculated, and the second duration of each of the second residuals of the at least one vehicle within the preset residual interval is calculated respectively.

[0074] The maximum value of the mean of the second residuals of the at least one vehicle is used as the residual threshold, and the maximum value of the second duration is used as the time threshold.

[0075] As a concrete example, the steer-by-wire system inputs a second target steering wheel angle with a rotational speed of n, where n is the maximum rotational speed required by the autonomous driving domain controller for the steer-by-wire system, i.e., the passive maximum required rotational speed of the steer-by-wire system mentioned earlier. The second actual steering wheel angle SW responding to this input is then calculated. rt With the second theoretical steering wheel angle SW it The second residual e t For the second residual e t The distribution of the variables was statistically analyzed, and the mean e was obtained. tu With standard deviation σ u Statistical test data e t From e tu -σ u to e tu +σ u Duration t m The above test was performed on m vehicles of the same model with normal lateral tracking function. tu and t m Statistical analysis was conducted, and e was taken. tu and t m The maximum value in the range is used as the residual threshold d and the time threshold t.

[0076] It should be noted that when the residual threshold and time threshold are obtained by conducting multiple statistical tests on the same vehicle of the same model, the maximum value of the mean of the second residual is the mean of the second residual of that vehicle, and the maximum value of the second duration is also the maximum value of the second duration of that vehicle.

[0077] The steer-by-wire system diagnostic method of this disclosure takes the entire steer-by-wire system as the diagnostic object. By establishing a steer-by-wire system model of the entire steer-by-wire system, the theoretical steering angle is obtained based on the input target steering wheel angle and the model. The steering performance of the steer-by-wire system is determined based on the theoretical steering wheel angle and the actual steering wheel angle of the steer-by-wire system. This allows for timely detection of whether the steering performance of the steer-by-wire system has deteriorated, thereby improving the safety performance of autonomous vehicles equipped with this steer-by-wire system and reducing the operating costs of autonomous vehicles.

[0078] The following will combine Figure 3 The principle of the steer-by-wire system diagnostic method according to the embodiments of this disclosure will be explained in detail.

[0079] like Figure 3 As shown, when the diagnostic method is running, the autonomous driving domain controller sends the target steering wheel angle SW. t The steer-by-wire system responds to the target steering angle with an actual steering wheel angle SW. r Meanwhile, the autonomous driving domain controller determines the target steering wheel angle SW. t The theoretical steering wheel angle SW is calculated using the steer-by-wire system model M. i Real-time calculation of SW r With SW i The residual e between the two is used to start timing. When the residual e is greater than the residual threshold d, timing is started. If the residual is less than d, timing is reset to 0. If the timing time is greater than the time threshold t, it is considered that the steering system has experienced steering attenuation, that is, the steering system has malfunctioned.

[0080] This disclosure also provides a diagnostic device for a steer-by-wire system. Figure 4 A schematic diagram of one embodiment of a diagnostic device for a steer-by-wire system according to the present disclosure is shown. This diagnostic device can be used to perform the diagnostic methods described above, and details can be found in the relevant descriptions above, which will not be repeated here.

[0081] like Figure 4As shown, the diagnostic device 300 includes a sending module 310, a calculation module 320, and a diagnostic module 330. The sending module 310 sends a first target steering wheel angle to the steer-by-wire system to obtain a first actual steering wheel angle in response to the steer-by-wire system. The calculation module 320 calculates a first theoretical steering wheel angle based on the first target steering wheel angle and a pre-established steer-by-wire system model. The calculation module 320 also calculates a first residual between the first actual steering wheel angle and the first theoretical steering wheel angle. The diagnostic module 330 determines whether a first duration for which the first residual is greater than a residual threshold is greater than a time threshold; if so, it determines that the steering performance of the steer-by-wire system has degraded.

[0082] The steer-by-wire system diagnostic device of this embodiment takes the entire steer-by-wire system as the diagnostic object. By establishing a steer-by-wire system model of the entire steer-by-wire system, the theoretical steering angle is obtained based on the input target steering wheel angle and the model. The steering performance of the steer-by-wire system is determined based on the theoretical steering wheel angle and the actual steering wheel angle of the steer-by-wire system. This allows for timely detection of whether the steering performance of the steer-by-wire system has deteriorated, thereby improving the safety performance of autonomous vehicles equipped with the steer-by-wire system and reducing the operating cost of autonomous vehicles.

[0083] This disclosure also provides an autonomous driving domain controller. Figure 5 A schematic diagram of an embodiment of an autonomous driving domain controller according to the present disclosure is shown. This autonomous driving domain controller can be used to perform the diagnostic methods described above. For details, please refer to the relevant descriptions above, which will not be repeated here.

[0084] like Figure 5 As shown, the autonomous driving domain controller 210 includes a sending unit 211, a calculation unit 212, and a diagnostic unit 213. The sending unit 211 sends a first target steering wheel angle to the steer-by-wire system to obtain a first actual steering wheel angle in response to the steer-by-wire system. The calculation unit 212 calculates a first theoretical steering wheel angle based on the first target steering wheel angle and a pre-established steer-by-wire system model. The calculation unit 212 also calculates a first residual between the first actual steering wheel angle and the first theoretical steering wheel angle. The diagnostic unit 213 determines whether a first duration during which the first residual is greater than a residual threshold is greater than a time threshold; if so, it determines that the steering performance of the steer-by-wire system has degraded.

[0085] The autonomous driving domain controller of this disclosure treats the entire steer-by-wire system as a diagnostic object. By establishing a steer-by-wire system model of the entire system, the theoretical steering angle is obtained based on the input target steering wheel angle and the model. The steering performance of the steer-by-wire system is determined based on the theoretical steering wheel angle and the actual steering wheel angle of the system. This allows for timely detection of any degradation in the steering performance of the steer-by-wire system, thereby improving the safety performance of autonomous vehicles equipped with this system and reducing their operating costs.

[0086] This disclosure also provides an electronic device for performing the diagnostic methods described above. Figure 6 A block diagram of the electronic device used to perform the diagnostic method for the steering-by-wire system disclosed herein is shown.

[0087] like Figure 6 As shown, an electronic device 400 includes one or more processors 410 and a storage unit 412. The storage unit 412 is used to store one or more programs, which, when executed by the one or more processors 410, enable the one or more processors 410 to perform the method described above.

[0088] This disclosure also provides a computer-readable storage medium for storing a computer program that can be processed and executed to implement the methods described above.

[0089] The computer-readable storage medium may be any tangible medium that contains or stores a program, and may be an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device. More specific examples include, but are not limited to, electrical connections having one or more wires, portable computer disks, hard disks, optical fibers, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0090] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A diagnostic method for a steer-by-wire system, characterized in that, The method includes: The first target steering wheel angle is sent to the steer-by-wire system to obtain the first actual steering wheel angle in response to the steer-by-wire system. Based on the first target steering wheel angle and the pre-established steer-by-wire system model, the first theoretical steering wheel angle is calculated; the steer-by-wire system model is established using the following steps: A frequency sweep test was performed on the steer-by-wire system, and the frequency response curve of the steer-by-wire system was obtained based on the results of the frequency sweep test. Based on the frequency response curve, the amplitude-frequency response characteristics of the steer-by-wire system are obtained; Based on the amplitude-frequency response characteristics, the steer-by-wire system model is obtained; Calculate the first residual between the first actual steering wheel angle and the first theoretical steering wheel angle; Determine whether the first duration for which the first residual is greater than the residual threshold is greater than the time threshold; if so, determine that the steering performance of the steer-by-wire system has degraded. The method further includes: The second target steering wheel angle is sent multiple times to the steer-by-wire system of at least one vehicle of the same model to obtain the second actual steering wheel angle in response to the steer-by-wire system; wherein, the input speed of the second target steering wheel angle is the passive maximum required speed of the steer-by-wire system; The second theoretical steering wheel angle is calculated based on the second target steering wheel angle and the steer-by-wire system model. Calculate the second residuals of each of the second actual steering wheel angles and the second theoretical steering wheel angles of the at least one vehicle, and calculate the mean and standard deviation of the second residuals of the at least one vehicle, and calculate the second duration of each of the second residuals of the at least one vehicle within a preset residual interval. The maximum value of the mean of the second residuals of the at least one vehicle is used as the residual threshold, and the maximum value of the second duration is used as the time threshold.

2. The method according to claim 1, characterized in that, The method further includes: Timing is initiated when the first residual is greater than the residual threshold to generate the first duration.

3. The method according to claim 1, characterized in that, The first target steering wheel angle is generated by the autonomous driving domain controller.

4. The method according to any one of claims 1 to 3, characterized in that, The steer-by-wire system model adopts a second-order transfer function model, as shown in equations (1) and (2) below: （1） （2） Where M(z) is the transfer function, z is the z-transformation factor, a and b are both coefficients, c is a constant term, Y(z) is the z-transformation of the theoretical steering wheel angle, and U(z) is the z-transformation of the target steering wheel angle.

5. A diagnostic device for a steer-by-wire system, characterized in that, The device includes: The sending module is used to send the first target steering wheel angle to the steer-by-wire system and obtain the first actual steering wheel angle in response to the steer-by-wire system. The calculation module is used to calculate the first theoretical steering wheel angle based on the first target steering wheel angle and the pre-established steer-by-wire system model; the steer-by-wire system model is established using the following steps: A frequency sweep test was performed on the steer-by-wire system, and the frequency response curve of the steer-by-wire system was obtained based on the results of the frequency sweep test. Based on the frequency response curve, the amplitude-frequency response characteristics of the steer-by-wire system are obtained; Based on the amplitude-frequency response characteristics, the steer-by-wire system model is obtained; The calculation module is also used to calculate the first residual between the first actual steering wheel angle and the first theoretical steering wheel angle; The diagnostic module is used to determine whether the first duration for which the first residual is greater than the residual threshold is greater than the time threshold. If so, it determines that the steering performance of the steer-by-wire system has degraded. The second target steering wheel angle is sent multiple times to the steer-by-wire system of at least one vehicle of the same model to obtain the second actual steering wheel angle in response to the steer-by-wire system; wherein, the input speed of the second target steering wheel angle is the passive maximum required speed of the steer-by-wire system; The second theoretical steering wheel angle is calculated based on the second target steering wheel angle and the steer-by-wire system model. Calculate the second residuals of each of the second actual steering wheel angles and the second theoretical steering wheel angles of the at least one vehicle, and calculate the mean and standard deviation of the second residuals of the at least one vehicle, and calculate the second duration of each of the second residuals of the at least one vehicle within a preset residual interval. The maximum value of the mean of the second residuals of the at least one vehicle is used as the residual threshold, and the maximum value of the second duration is used as the time threshold.

6. An autonomous driving domain controller, characterized in that, include: The transmitting unit is used to send the first target steering wheel angle to the steer-by-wire system and obtain the first actual steering wheel angle responded by the steer-by-wire system. The calculation unit is used to calculate the first theoretical steering wheel angle based on the first target steering wheel angle and the pre-established steer-by-wire system model; the steer-by-wire system model is established using the following steps: A frequency sweep test was performed on the steer-by-wire system, and the frequency response curve of the steer-by-wire system was obtained based on the results of the frequency sweep test. Based on the frequency response curve, the amplitude-frequency response characteristics of the steer-by-wire system are obtained; Based on the amplitude-frequency response characteristics, the steer-by-wire system model is obtained; The calculation unit is also used to calculate the first residual between the first actual steering wheel angle and the first theoretical steering wheel angle; The diagnostic unit is used to determine whether the first duration for which the first residual is greater than the residual threshold is greater than the time threshold. If so, it determines that the steering performance of the steer-by-wire system has degraded. The second target steering wheel angle is sent multiple times to the steer-by-wire system of at least one vehicle of the same model to obtain the second actual steering wheel angle in response to the steer-by-wire system; wherein, the input speed of the second target steering wheel angle is the passive maximum required speed of the steer-by-wire system; The second theoretical steering wheel angle is calculated based on the second target steering wheel angle and the steer-by-wire system model. Calculate the second residuals of each of the second actual steering wheel angles and the second theoretical steering wheel angles of the at least one vehicle, and calculate the mean and standard deviation of the second residuals of the at least one vehicle, and calculate the second duration of each of the second residuals of the at least one vehicle within a preset residual interval. The maximum value of the mean of the second residuals of the at least one vehicle is used as the residual threshold, and the maximum value of the second duration is used as the time threshold.

7. An electronic device, characterized in that, include: One or more processors; A storage unit for storing one or more programs that, when executed by one or more processors, enable the one or more processors to implement the method according to any one of claims 1 to 4.

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