Fault-tolerant control method and device for vehicle steer-by-wire system, vehicle and medium

Abstract

The invention relates to a fault-tolerant control method and device for a vehicle steer-by-wire system, a vehicle and a medium, and the method comprises the steps that after the vehicle is powered on, the steering wheel angle variation of the vehicle based on an electrical angle is obtained; obtaining a reference starting point value of the steering wheel angle and a steering wheel angle reference starting point value corresponding to the electrical angle; the steering wheel angle theoretical value of the vehicle is estimated based on the steering wheel angle change amount of the electrical angle, the reference starting point value of the steering wheel angle and the steering wheel angle reference starting point value corresponding to the electrical angle, and fault-tolerant control of vehicle steering is performed based on the steering wheel angle theoretical value when the failure of an angle sensor of the steering wheel is detected. Therefore, the problems that in the related technology, system cost, size and weight can be increased by adding a third angle sensor backup, other system space can be compressed, a whole vehicle degradation strategy for effectively coping with a steering wheel sensor failure working condition scheme is lacked, so that a vehicle cannot continue to run, the actual use experience of a user is affected, and the service life of the user is prolonged are solved. And a relatively large potential safety hazard also exists.

Description

Technical Field

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

[0002] In the SBW (Steer By Wire) system, there is no mechanical connection between the steering wheel and the wheel steering mechanism. The HWA (Hand Wheel Actuator) detects the user's steering wheel angle input through the steering wheel angle sensor, and then instructs the RWA (Rear Wheel Assist) to turn the wheel to the target angle through an electrical signal. For the SBW system, HWA has adopted a dual redundant system to achieve the ASIL D level safety target. However, for the OEM to apply SBW, the user's availability needs to be considered. During the vehicle's driving, if the HWA's steering wheel angle sensor fails at two points, the system cannot obtain the user's steering wheel angle request, and will not be able to calculate the RWA's target rack displacement / angle, resulting in the vehicle losing the ability to control the vehicle's lateral motion during driving. This poses a challenge to the design of the vehicle's lateral backup control. Therefore, compared with the traditional steering system, the SBW system requires a higher level of fault tolerance to avoid losing the vehicle's lateral motion control.

[0003] In order to deal with the double-point failure of the steering wheel angle sensor of HWA during vehicle driving, in the related art, a third redundant SAS (Steering Angle Sensor) sensor can be added and connected to the domain controller or other controller. In the event of a double-point failure of the steering wheel angle sensor, the angle information of the additional SAS sensor is used to obtain the user's steering wheel angle input, calculate the target rack displacement / angle and send it to RWA to maintain the vehicle's steering ability. However, although adding a backup of the third angle sensor can effectively avoid / solve this problem, too many sensor backups will increase system cost, volume and weight, and compress other system space. In the related art, the whole vehicle degradation strategy can also be used to achieve emergency control of the vehicle without adding a third redundant SAS sensor. Although it can avoid safety accidents caused by loss of control of the steering wheel during driving, it will cause the vehicle to be unable to continue driving, so that the user can only wait for rescue on the spot, affecting the user's travel itinerary. At the same time, the vehicle is parked in the middle of the road, and there is a greater risk of collision.

[0004] To sum up, in the relevant technology, adding a third angle sensor backup will increase the system cost, volume and weight, and will compress the space for other systems. The lack of a vehicle degradation strategy to effectively deal with the steering wheel sensor failure condition will cause the vehicle to be unable to continue driving, which not only affects the user's actual usage experience, but also poses a major safety hazard and needs to be improved. Summary of the invention

[0005] The present application provides a fault-tolerant control method, device, vehicle and medium for a vehicle's wire-controlled steering system to solve the technical problems in the related art that adding a third angle sensor backup will increase the system cost, volume and weight, and will compress the space for other systems, and the lack of a vehicle degradation strategy that effectively copes with the steering wheel sensor failure condition will cause the vehicle to be unable to continue driving, which not only affects the user's actual usage experience, but also poses a major safety hazard.

[0006] A first aspect embodiment of the present application provides a fault-tolerant control method for a vehicle's steer-by-wire system, comprising the following steps: after the vehicle is powered on, obtaining a steering wheel angle change of the vehicle based on an electrical angle; obtaining a reference starting value of the steering wheel angle and a steering wheel angle reference starting value corresponding to the electrical angle; estimating a first steering wheel angle theoretical value of the vehicle based on the steering wheel angle change of the electrical angle, the reference starting value of the steering wheel angle and the steering wheel angle reference starting value corresponding to the electrical angle, and in the event that a steering wheel angle sensor detecting the steering wheel fails, performing fault-tolerant control of the vehicle's steering based on the first steering wheel angle theoretical value.

[0007] Optionally, in one embodiment of the present application, obtaining the reference starting point value of the steering wheel angle and the reference starting point value of the steering wheel angle corresponding to the electrical angle includes: obtaining the sensor status of the vehicle; judging whether the vehicle meets a preset starting angle self-learning condition based on the sensor status; if the vehicle meets the starting angle self-learning condition, calculating the reference starting point value of the steering wheel angle and the reference starting point value of the steering wheel angle of the electrical angle based on the historical steering wheel angle data of the steering wheel and the steering wheel angle change of the electrical angle.

[0008] Optionally, in one embodiment of the present application, after estimating the first theoretical steering wheel angle of the vehicle, it also includes: estimating the second theoretical steering wheel angle of the steering wheel backup electrical system of the vehicle; comparing the first theoretical steering wheel angle, the second theoretical steering wheel angle and the steering wheel angle sensor angle to obtain a quantitative feedback value of the steering wheel angle of the vehicle; determining the steering wheel control angle of the vehicle based on the quantitative feedback value, so as to perform fault-tolerant control of the vehicle steering based on the steering wheel control angle.

[0009] Optionally, in one embodiment of the present application, after estimating the first theoretical steering wheel angle of the vehicle, it also includes: switching the flag of the first theoretical steering wheel angle to a first available flag to allow the first theoretical steering wheel angle to be called; and / or, after estimating the second theoretical steering wheel angle, it also includes: switching the flag of the second theoretical steering wheel angle to a second available flag to allow the second theoretical steering wheel angle to be called.

[0010] Optionally, in one embodiment of the present application, determining the steering wheel control angle of the vehicle based on the quantitative feedback value includes: determining whether the first steering wheel theoretical angle and the second steering wheel theoretical angle are valid based on the first available flag bit and the second available flag bit respectively; if the first steering wheel theoretical angle and the second steering wheel theoretical angle are both valid, calculating the angle difference between the first steering wheel theoretical angle and the second steering wheel theoretical angle, and judging whether the angle difference is less than a preset threshold; if the angle difference is less than the preset threshold, determining the steering wheel control angle using the first steering wheel theoretical angle or the second steering wheel theoretical angle; if the angle difference is greater than or equal to the preset threshold, calculating the difference between the first steering wheel theoretical angle and the second steering wheel theoretical angle and the angle of the steering wheel angle sensor respectively, and determining the steering wheel control angle based on the difference.

[0011] Optionally, in one embodiment of the present application, after determining whether the first theoretical steering wheel angle and the second theoretical steering wheel angle are valid based on the first available flag bit and the second available flag bit respectively, it also includes: if the first theoretical steering wheel angle is valid and the second theoretical steering wheel angle is invalid, then determining the steering wheel control angle based on the first theoretical steering wheel angle; if the second theoretical steering wheel angle is valid and the first theoretical steering wheel angle is invalid, then determining the steering wheel control angle based on the second theoretical steering wheel angle.

[0012] Optionally, in one embodiment of the present application, after determining whether the first theoretical steering wheel angle and the second theoretical steering wheel angle are valid based on the first available flag bit and the second available flag bit respectively, it also includes: if both the first theoretical steering wheel angle and the second theoretical steering wheel angle are invalid, executing the vehicle downgrade strategy of the vehicle.

[0013] A second aspect of the present application provides a fault-tolerant control device for a vehicle's steer-by-wire system, comprising: a first acquisition module, used to acquire a steering wheel angle change of the vehicle based on an electrical angle after the vehicle is powered on; a second acquisition module, used to acquire a reference starting value of the steering wheel angle and a reference starting value of the steering wheel angle corresponding to the electrical angle; a first control module, used to estimate a first theoretical steering wheel angle value of the vehicle based on the steering wheel angle change of the electrical angle, the reference starting value of the steering wheel angle and the reference starting value of the steering wheel angle corresponding to the electrical angle, and to perform fault-tolerant control of the vehicle's steering based on the first theoretical steering wheel angle value when a steering wheel angle sensor fails.

[0014] Optionally, in one embodiment of the present application, the second acquisition module includes: an acquisition unit for acquiring the sensor status of the vehicle; a first judgment unit for judging whether the vehicle meets a preset starting angle self-learning condition based on the sensor status; and a calculation unit for calculating a reference starting point value of the steering wheel angle and a reference starting point value of the steering wheel angle of the electrical angle based on the historical steering wheel angle data of the steering wheel and the steering wheel angle change of the electrical angle when the vehicle meets the starting angle self-learning condition.

[0015] Optionally, in one embodiment of the present application, it also includes: an estimation module, used to estimate a second steering wheel theoretical angle of the vehicle's steering wheel backup electrical system; a calculation module, used to compare the first steering wheel theoretical angle, the second steering wheel theoretical angle and the steering wheel angle sensor angle to obtain a quantitative feedback value of the vehicle's steering wheel angle; a second control module, used to determine the vehicle's steering wheel control angle based on the quantitative feedback value, so as to perform fault-tolerant control of the vehicle's steering based on the steering wheel control angle.

[0016] Optionally, in one embodiment of the present application, it also includes: a first switching module, used to switch the flag bit of the first steering wheel angle theoretical value to a first available flag bit to allow the first steering wheel angle theoretical value to be called; and / or, it also includes: a second switching module, used to switch the flag bit of the second steering wheel angle theoretical value to a second available flag bit to allow the second steering wheel theoretical angle to be called.

[0017] Optionally, in one embodiment of the present application, the second control module includes: a first determination unit, used to determine whether the first steering wheel theoretical angle and the second steering wheel theoretical angle are valid based on the first available flag bit and the second available flag bit; a second judgment unit, used to calculate the angle difference between the first steering wheel theoretical angle and the second steering wheel theoretical angle when both the first steering wheel theoretical angle and the second steering wheel theoretical angle are valid, and judge whether the angle difference is less than a preset threshold; a second determination unit, used to determine the steering wheel control angle using the first steering wheel theoretical angle or the second steering wheel theoretical angle when the angle difference is less than the preset threshold; a third determination unit, used to calculate the difference between the first steering wheel theoretical angle and the second steering wheel theoretical angle and the steering wheel angle sensor angle when the angle difference is greater than or equal to the preset threshold, and determine the steering wheel control angle based on the difference.

[0018] Optionally, in one embodiment of the present application, the second control module also includes: a fourth determination unit, used to determine the steering wheel control angle based on the first steering wheel theoretical angle when the first steering wheel theoretical angle is valid and the second steering wheel theoretical angle is invalid; a fifth determination unit, used to determine the steering wheel control angle based on the second steering wheel theoretical angle when the second steering wheel theoretical angle is valid and the first steering wheel theoretical angle is invalid.

[0019] Optionally, in one embodiment of the present application, the second control module further includes: a sixth determination unit, configured to execute a vehicle degradation strategy for the vehicle when both the first theoretical steering wheel angle and the second theoretical steering wheel angle are invalid.

[0020] A third aspect of the present application provides a vehicle, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the fault-tolerant control method of the vehicle's steer-by-wire system as described in the above embodiment.

[0021] A fourth aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the fault-tolerant control method of the vehicle steer-by-wire system as described in the above embodiments.

[0022] The fifth aspect of the present application provides a computer program product, including a computer program, which, when executed, is used to implement the fault-tolerant control method of the vehicle wire-controlled steering system as described above.

[0023] After the vehicle is powered on, the embodiment of the present application can obtain the steering wheel angle change based on the electrical angle, the reference starting value of the steering wheel angle and the reference starting value of the steering wheel angle corresponding to the electrical angle, and then estimate the theoretical value of the steering wheel angle of the vehicle, so that when the steering wheel angle sensor fails, the theoretical value of the steering wheel angle can be used to perform fault-tolerant control of the vehicle steering, and the steering wheel angle can be calculated using the motor electrical angle without adding additional redundant components, so as to identify the user's steering angle input to maintain the normal steering operation of the SBW, so that the vehicle can still drive normally according to user needs when the steering wheel angle sensor fails, ensuring the user's driving experience and effectively improving the safety performance of the vehicle. Thus, the technical problem that adding a third angle sensor backup in the related technology will increase the system cost, volume and weight, and will compress the space of other systems, and the lack of a vehicle downgrade strategy that effectively responds to the steering wheel sensor failure working condition will cause the vehicle to be unable to continue driving, which not only affects the user's actual use experience, but also has a large safety hazard.

[0024] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0026] Figure 1 A flowchart of a fault-tolerant control method for a vehicle steer-by-wire system provided according to an embodiment of the present application;

[0027] Figure 2 A schematic diagram of the principle of a fault-tolerant control method for a vehicle steer-by-wire system according to an embodiment of the present application;

[0028] Figure 3 A schematic structural diagram of a fault-tolerant control device for a vehicle steer-by-wire system provided according to an embodiment of the present application;

[0029] Figure 4 It is a schematic diagram of the structure of a vehicle provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0030] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0031] The following describes the fault-tolerant control method, device, vehicle and medium of the vehicle wire steering system of the embodiment of the present application with reference to the accompanying drawings. In view of the related technologies mentioned in the above background technology, in the related technologies, adding a third angle sensor backup will increase the system cost, volume and weight, and will compress the space of other systems, and the lack of a vehicle degradation strategy that effectively responds to the steering wheel sensor failure working condition solution will cause the vehicle to be unable to continue driving, which not only affects the actual user experience, but also has a large technical problem of potential safety hazards. The present application provides a fault-tolerant control method for a vehicle wire steering system, in which after the vehicle is powered on, the steering wheel angle change based on the electrical angle of the vehicle, the reference starting value of the steering wheel angle and the reference starting value of the steering wheel angle corresponding to the electrical angle can be obtained, and then the theoretical value of the steering wheel angle of the vehicle can be estimated, so that when the steering wheel angle sensor fails, the theoretical value of the steering wheel angle can be used to perform fault-tolerant control of the vehicle steering, and the steering wheel angle can be calculated using the motor electrical angle without adding additional redundant components, so as to identify the user's steering angle input to maintain the normal steering operation of the SBW, so that the vehicle can still drive normally according to the user's needs when the steering wheel angle sensor fails, ensuring the user's driving experience and effectively improving the safety performance of the vehicle. Thereby, the technical problem in the related technology that adding a third angle sensor backup will increase the system cost, volume and weight and will compress the space for other systems, while the lack of a vehicle degradation strategy to effectively deal with the steering wheel sensor failure condition will cause the vehicle to be unable to continue driving, which not only affects the user's actual usage experience but also poses a major safety hazard.

[0032] Specifically, Figure 1 A flow chart of a fault-tolerant control method for a vehicle steer-by-wire system provided in an embodiment of the present application.

[0033] like Figure 1 As shown, the fault-tolerant control method of the vehicle wire-controlled steering system includes the following steps:

[0034] In step S101, after the vehicle is powered on, a steering wheel angle change based on an electrical angle of the vehicle is obtained.

[0035] As a possible implementation method, after the HWA system is powered on and initialized, in the cycle scheduling of the motor control, the change in the number of electrical cycles is determined and counted based on the difference between the current motor electrical angle and the electrical angle of the previous cycle taking into account the direction sign. The embodiment of the present application can convert the sum of the current motor electrical angle and 360*the number of electrical cycles into the steering wheel angle change based on the number of pole pairs, gear ratio and the resolution of the steering wheel angle sensor.

[0036] For example, in the embodiment of the present application, after the HWA system is powered on and initialized, in the periodic scheduling of the HWA motor control, the motor electrical angle of the current cycle can be read, and it can be converted into the steering wheel angle change according to the following formula:

[0037]

[0038] Among them, Δδ is the steering wheel angle change converted from the motor electrical angle; θ n is the motor electrical angle of the current cycle taking into account the direction sign, which is the angle information that is already available in the motor control algorithm; t θ is the number of cycles of the motor electrical angle change; P is the number of pole pairs of the motor; G is the transmission ratio of the HWA reduction mechanism; K w is the resolution of the steering wheel angle; K m is the resolution in electrical degrees.

[0039] Due to the high real-time requirements of motor control, the motor control cycle is set to the microsecond level. In this embodiment of the application, the electrical angle change between two adjacent motor control cycles does not exceed 360 degrees. Therefore, the number of motor electrical angle change cycles can be accumulated according to the following formula:

[0040]

[0041] Among them, t θ is the number of cycles of the motor electrical angle change, θ n is the motor electrical angle of the current cycle taking into account the direction sign, θ l is the motor electrical angle of the previous cycle taking the direction sign into account.

[0042] In step S102, a reference starting point value of the steering wheel angle and a reference starting point value of the steering wheel angle corresponding to the electrical angle are obtained.

[0043] Furthermore, the embodiment of the present application can obtain the reference starting point value of the steering wheel angle and the reference starting point value of the steering wheel angle corresponding to the electrical angle through starting angle self-learning.

[0044] Optionally, in one embodiment of the present application, obtaining a reference starting point value of the steering wheel angle and a reference starting point value of the steering wheel angle corresponding to the electrical angle includes: obtaining a sensor status of the vehicle; judging whether the vehicle meets a preset starting angle self-learning condition based on the sensor status; if the vehicle meets the starting angle self-learning condition, calculating a reference starting point value of the steering wheel angle and a reference starting point value of the steering wheel angle corresponding to the electrical angle based on historical steering wheel angle data of the steering wheel and the steering wheel angle change of the electrical angle.

[0045] During the actual implementation process, the embodiment of the present application can perform starting angle self-learning condition determination after power-on, thereby calculating the reference starting point value of the steering wheel angle and the steering wheel angle reference starting point value of the electrical angle based on the historical steering wheel angle data of the steering wheel and the steering wheel angle change of the electrical angle.

[0046] For example, in the application periodic scheduling, if the following conditions are met, the embodiment of the present application can start the starting angle self-learning:

[0047] The steering wheel angle sensor calibration flag is ON;

[0048] And there is no abnormality in the steering wheel angle sensor;

[0049] And the HWA motor position sensor has no abnormality;

[0050] And the steering wheel angle initial reference value self-learning completion flag is OFF.

[0051] The current steering wheel angle data detected by the steering wheel angle sensor and the steering wheel angle change calculated based on the electrical angle are stored continuously m times (the number of times can be calibrated).

[0052] To ensure the reliability of the data, after collecting the angle data of the steering wheel angle sensor for m consecutive times, the deviation of the maximum and minimum values ​​is calculated. If the deviation exceeds a certain threshold (the threshold can be calibrated), the data is judged to be unreliable, and the steering wheel angles of the steering wheel angle sensor for m times stored and the steering wheel angle change calculated based on the electrical angle are cleared at the same time.

[0053] If the deviation meets the threshold range, the angle data of the m steering wheel angle sensor and the steering wheel angle change calculated based on the electrical angle are averaged and the average values ​​are used as the reference starting point values ​​δ of the steering wheel angle. wr The steering wheel angle reference starting point value δ corresponding to the electrical angle mr The data is saved and the start angle self-learning completion flag is set to ON.

[0054] In step S103, a first steering wheel angle theoretical value of the vehicle is estimated based on the steering wheel angle change of the electrical angle, the reference starting value of the steering wheel angle and the steering wheel angle reference starting value corresponding to the electrical angle. In case the angle sensor detecting the steering wheel fails, fault-tolerant control of the vehicle steering is performed based on the first steering wheel angle theoretical value.

[0055] After the steering wheel angle starting reference value self-learning completion flag is ON, the embodiment of the present application can calculate the steering wheel angle change Δδ of the current electrical angle in the periodic scheduling of the motor control, and calculate the first steering wheel theoretical angle δ based on the following formula E:

[0056] δ E =(δ wr +Δδ)-δ mr .

[0057] Finally, the embodiment of the present application can set the first steering wheel theoretical angle available flag to ON.

[0058] Based on the above estimation results, the embodiment of the present application can call the estimated first steering wheel theoretical angle when the steering wheel of the vehicle fails, thereby achieving fault-tolerant control of the vehicle steering.

[0059] Optionally, in one embodiment of the present application, after estimating the first theoretical steering wheel angle of the vehicle, it also includes: estimating the second theoretical steering wheel angle of the vehicle's steering wheel backup electrical system; comparing the first theoretical steering wheel angle, the second theoretical steering wheel angle and the steering wheel angle sensor angle to obtain a quantitative feedback value of the vehicle's steering wheel angle; determining the vehicle's steering wheel control angle based on the quantitative feedback value, so as to perform fault-tolerant control of the vehicle steering based on the steering wheel control angle.

[0060] It is understandable that the HWA system is usually set up as a dual system to ensure the driving safety of the vehicle. In the redundant backup electrical system, the embodiment of the present application can also execute the above logic to calculate the second steering wheel theoretical angle of the backup system. The dual systems can send their respective estimated steering wheel theoretical angles and available flags to each other for mutual verification.

[0061] For example, the embodiments of the present application can estimate the quantitative feedback value of the steering wheel angle by comparing the first theoretical steering wheel angle, the second theoretical steering wheel angle and the steering wheel angle sensor angle, thereby determining the control angle of the steering wheel according to the quantitative feedback value, and then determining the target angle of the wheel, thereby achieving fault-tolerant control of vehicle steering.

[0062] Optionally, in one embodiment of the present application, after estimating the first theoretical steering wheel angle of the vehicle, it also includes: switching the flag of the first theoretical steering wheel angle to a first available flag to allow the first theoretical steering wheel angle to be called; and / or, after estimating the second theoretical steering wheel angle, it also includes: switching the flag of the second theoretical steering wheel angle to a second available flag to allow the second theoretical steering wheel angle to be called.

[0063] In the embodiment of the present application, after the first steering wheel angle theoretical value is calculated, it can be determined that the first steering wheel angle theoretical value can be called, and the flag bit can be switched to the first available flag bit.

[0064] Similarly, in the case of a dual system, after the second steering wheel angle theoretical value is calculated, it is determined that the second steering wheel angle theoretical value can be called, and the flag is switched to the second available flag.

[0065] Optionally, in one embodiment of the present application, the steering wheel control angle of the vehicle is determined based on a quantitative feedback value, including: determining whether the first steering wheel theoretical angle and the second steering wheel theoretical angle are valid based on a first available flag bit and a second available flag bit respectively; if both the first steering wheel theoretical angle and the second steering wheel theoretical angle are valid, calculating the angle difference between the first steering wheel theoretical angle and the second steering wheel theoretical angle, and judging whether the angle difference is less than a preset threshold; if the angle difference is less than the preset threshold, determining the steering wheel control angle using the first steering wheel theoretical angle or the second steering wheel theoretical angle; if the angle difference is greater than or equal to the preset threshold, calculating the difference between the first steering wheel theoretical angle and the second steering wheel theoretical angle and the steering wheel angle sensor angle, and determining the steering wheel control angle based on the difference.

[0066] In the embodiment of the present application, the main electrical system may be set as system A, the backup electrical system may be set as system B, and the determination logic of the quantitative feedback value may be as shown in Table 1, wherein Table 1 is a quantitative feedback value determination table.

[0067] Table 1

[0068]

[0069]

[0070] Optionally, in one embodiment of the present application, after determining whether the first steering wheel theoretical angle and the second steering wheel theoretical angle are valid based on the first available flag bit and the second available flag bit respectively, it also includes: if the first steering wheel theoretical angle is valid and the second steering wheel theoretical angle is invalid, then determining the steering wheel control angle based on the first steering wheel theoretical angle; if the second steering wheel theoretical angle is valid and the first steering wheel theoretical angle is invalid, then determining the steering wheel control angle based on the second steering wheel theoretical angle.

[0071] As shown in Table 1, when the estimated theoretical steering wheel angle of any electrical system is invalid, the embodiment of the present application can select a valid theoretical steering wheel angle to determine the steering wheel control angle, thereby achieving redundant control of vehicle steering.

[0072] Optionally, in one embodiment of the present application, after determining whether the first theoretical steering wheel angle and the second theoretical steering wheel angle are valid based on the first available flag bit and the second available flag bit respectively, it also includes: if both the first theoretical steering wheel angle and the second theoretical steering wheel angle are invalid, executing the vehicle downgrade strategy.

[0073] As a possible implementation method, after detecting that the steering wheel angle sensors of both HWA systems have failed, the embodiment of the present application can determine the quantitative feedback value QF of the theoretical steering wheel angle. If QF>=2, the corresponding theoretical steering wheel angle output value is used to calculate the target rack displacement / angle, and the wheel rotation is performed for RWA. If QF<2, the original vehicle degradation strategy is executed.

[0074] Combination Figure 2 As shown, the working principle of the fault-tolerant control method of the vehicle steer-by-wire system of the embodiment of the present application is described in detail by taking an embodiment as an example.

[0075] The embodiment of the present application can start learning the reference starting value of the steering wheel angle and the reference starting value of the steering wheel angle corresponding to the electrical angle after the HWA system is initialized. After the self-learning is completed, the steering wheel angle is estimated in real time based on the change in the electrical angle. This logic is executed in the dual redundant system of HWA. Then, the estimated steering wheel angle calculated by the two systems and the available flag bits are used for mutual verification to determine the estimated steering wheel angle output value (i.e., the steering wheel control angle) and the QF value. When a dual-point failure occurs in the steering wheel angle sensor, the steering wheel sensor can no longer detect the driver's angle input, and the estimated steering wheel angle is used as a substitute based on the QF value, allowing the user to continue driving to the repair shop or pull over.

[0076] like Figure 2 As shown, the embodiment of the present application may include the following steps:

[0077] Step S1: Calculate the steering wheel angle change based on the electrical angle.

[0078] After the HWA system is powered on and initialized, in the cycle scheduling of the motor control, the embodiment of the present application can determine the change in the number of electrical cycles and add or subtract counts thereof based on the difference between the current motor electrical angle and the electrical angle of the previous cycle taking into account the direction sign. Based on the sum of the current motor electrical angle and 360*the number of electrical cycles, and taking into account the number of pole pairs, gear ratio, and the resolution of the steering wheel angle sensor, it is converted into the steering wheel angle change.

[0079] For example, in the embodiment of the present application, after the HWA system is powered on and initialized, in the periodic scheduling of the HWA motor control, the motor electrical angle of the current cycle can be read, and it can be converted into the steering wheel angle change according to the following formula:

[0080]

[0081] Among them, Δδ is the steering wheel angle change converted from the motor electrical angle; θ n is the motor electrical angle of the current cycle taking into account the direction sign, which is the angle information that is already available in the motor control algorithm; tθ is the number of cycles of the motor electrical angle change; P is the number of pole pairs of the motor; G is the transmission ratio of the HWA reduction mechanism; K w is the resolution of the steering wheel angle; K m is the resolution in electrical degrees.

[0082] Due to the high real-time requirements of motor control, the motor control cycle is set to the microsecond level. In this embodiment of the application, the electrical angle change between two adjacent motor control cycles does not exceed 360 degrees. Therefore, the number of motor electrical angle change cycles can be accumulated according to the following formula:

[0083]

[0084] Among them, t θ is the number of cycles of the motor electrical angle change, θ n is the motor electrical angle of the current cycle taking into account the direction sign, θ l is the motor electrical angle of the previous cycle taking the direction sign into account.

[0085] Step S2: Self-learning with reference to the starting angle.

[0086] In the application cycle scheduling, if the following conditions are met, the start angle self-learning is started:

[0087] The steering wheel angle sensor calibration flag is ON;

[0088] And there is no abnormality in the steering wheel angle sensor;

[0089] And the HWA motor position sensor has no abnormality;

[0090] And the steering wheel angle initial reference value self-learning completion flag is OFF.

[0091] After the above conditions are met, the embodiment of the present application can continuously store m times (the number can be calibrated) of the current steering wheel angle data detected by the steering wheel angle sensor and the steering wheel angle change calculated based on the electrical angle in step S1.

[0092] To ensure the reliability of the data, after collecting the angle data of the steering wheel angle sensor for m consecutive times, the deviation of the maximum and minimum values ​​is calculated. If the deviation exceeds a certain threshold (the threshold can be calibrated), the data is judged to be unreliable, and the steering wheel angles of the steering wheel angle sensor for m times stored and the steering wheel angle change calculated based on the electrical angle are cleared at the same time.

[0093] If the deviation meets the threshold range, the angle data of the m steering wheel angle sensor and the steering wheel angle change calculated based on the electrical angle are averaged and the average values ​​are used as the reference starting point values ​​δ of the steering wheel angle.wr The steering wheel angle reference starting point value δ corresponding to the electrical angle mr The data is saved and the start angle self-learning completion flag is set to ON.

[0094] Step S3: Estimated steering wheel angle calculation.

[0095] After the steering wheel angle starting reference value self-learning completion flag is ON, as in step S1, the embodiment of the present application can calculate the steering wheel angle change Δδ of the current electrical angle in the periodic scheduling of the motor control, and calculate the first steering wheel theoretical angle δ based on the following formula E :

[0096] δ E =(δ wr +Δδ)-δ mr .

[0097] Finally, the embodiment of the present application can set the first steering wheel theoretical angle available flag to ON.

[0098] Step S4: Determine the QF value of the theoretical steering wheel angle.

[0099] The above logic is implemented synchronously in the HWA redundant system. The two systems send their estimated steering wheel theoretical angle and available flag to each other. The steering wheel theoretical angle and available flag are calculated using the motor electrical angle of the HWA redundant system for mutual verification. The specific judgment logic is shown in Table 1.

[0100] It should be noted that using only one channel to estimate the steering wheel angle can also meet the scenario of dual-point failure of the steering wheel angle sensor. Using two channels of steering wheel theoretical angles can not only verify each other, but also cover the scenario of failure of one motor or motor sensor, which improves robustness and safety level capabilities.

[0101] Step S5: Enable the steering wheel control angle.

[0102] After detecting that the steering wheel angle sensors of both HWA systems have failed, the embodiment of the present application can determine the theoretical steering wheel angle QF. If QF>=2, the output value of the theoretical steering wheel angle (i.e., the steering wheel control angle determined based on QF and the two theoretical steering wheel angles) is used to calculate the target rack displacement / angle, and the wheel rotation is performed for RWA. If QF<2, the original vehicle degradation strategy is executed.

[0103] In summary, the embodiments of the present application can use the steering wheel sensor angle information and the motor electrical angle information to perform self-learning of the starting angle when the vehicle is powered on, and the self-learning time is short, and the steering wheel angle can be estimated in real time without the user noticing. When a double-point failure occurs in the HWA steering wheel angle sensor, the estimated steering wheel angle is used to replace the angle information of the steering wheel angle sensor for control. All information comes from within the system and will not be affected by the delay of other sensor signals themselves or the delay of signal transmission. There is no need to add an additional power supply circuit to keep the HWA system running at all times after the vehicle is powered off, thereby wasting the energy consumption of the entire vehicle.

[0104] According to the fault-tolerant control method of the vehicle wire-controlled steering system proposed in the embodiment of the present application, after the vehicle is powered on, the steering wheel angle change based on the electrical angle, the reference starting value of the steering wheel angle and the reference starting value of the steering wheel angle corresponding to the electrical angle can be obtained, and then the theoretical value of the steering wheel angle of the vehicle can be estimated, so that when the steering wheel angle sensor fails, the theoretical value of the steering wheel angle can be used to perform fault-tolerant control of the vehicle steering, and the steering wheel angle can be calculated using the motor electrical angle without adding additional redundant components, so as to identify the user's steering angle input to maintain the normal steering operation of the SBW, so that the vehicle can still drive normally according to the user's needs when the steering wheel angle sensor fails, ensuring the user's driving experience and effectively improving the safety performance of the vehicle. Thus, the technical problem that adding a third angle sensor backup in the related art will increase the system cost, volume and weight, and will compress the space of other systems, and the lack of a vehicle degradation strategy that effectively responds to the steering wheel sensor failure working condition will cause the vehicle to be unable to continue driving, which not only affects the user's actual use experience, but also has a large safety hazard.

[0105] Next, the fault-tolerant control device for the vehicle steer-by-wire system proposed in accordance with the embodiment of the present application will be described with reference to the accompanying drawings.

[0106] Figure 3 It is a block diagram of a fault-tolerant control device for a vehicle steer-by-wire system according to an embodiment of the present application.

[0107] like Figure 3 As shown, the fault-tolerant control device 10 of the vehicle steer-by-wire system includes: a first acquisition module 100 , a second acquisition module 200 and a first control module 300 .

[0108] Specifically, the first acquisition module 100 is used to acquire the steering wheel angle change of the vehicle based on the electrical angle after the vehicle is powered on.

[0109] The second acquisition module 200 is used to acquire a reference starting point value of a steering wheel angle and a reference starting point value of a steering wheel angle corresponding to an electrical angle.

[0110] The first control module 300 is used to estimate a first steering wheel angle theoretical value of the vehicle based on a steering wheel angle change of an electrical angle, a reference starting point value of the steering wheel angle and a steering wheel angle reference starting point value corresponding to the electrical angle, and to perform fault-tolerant control of the vehicle steering based on the first steering wheel angle theoretical value when a steering wheel angle sensor fails.

[0111] Optionally, in one embodiment of the present application, the second acquisition module 200 includes: an acquisition unit, a first judgment unit and a calculation unit.

[0112] The acquisition unit is used to acquire the sensor status of the vehicle.

[0113] The first judgment unit is used to judge whether the vehicle meets a preset starting angle self-learning condition based on the sensor state.

[0114] A calculation unit is used to calculate a reference starting point value of the steering wheel angle and a reference starting point value of the steering wheel angle in electrical angle based on historical steering wheel angle data of the steering wheel and the steering wheel angle change in electrical angle when the vehicle meets the starting angle self-learning conditions.

[0115] Optionally, in one embodiment of the present application, the fault-tolerant control device 10 of the vehicle steer-by-wire system further includes: an estimation module, a calculation module and a second control module.

[0116] Among them, the estimation module is used to estimate the second steering wheel theoretical angle of the vehicle's steering wheel backup electrical system.

[0117] The calculation module is used to compare the first steering wheel theoretical angle, the second steering wheel theoretical angle and the steering wheel angle sensor angle to obtain a quantitative feedback value of the vehicle's steering wheel angle.

[0118] The second control module is used to determine a steering wheel control angle of the vehicle based on the quantitative feedback value, so as to perform fault-tolerant control of vehicle steering based on the steering wheel control angle.

[0119] Optionally, in one embodiment of the present application, it further includes: a first switching module and / or a second switching module.

[0120] Among them, the first switching module is used to switch the flag bit of the first steering wheel angle theoretical value to the first available flag bit to allow the first steering wheel angle theoretical value to be called.

[0121] The second switching module is used to switch the flag bit of the second steering wheel angle theoretical value to a second available flag bit to allow the second steering wheel theoretical angle to be called.

[0122] Optionally, in one embodiment of the present application, the second control module includes: a first determination unit, a second judgment unit, a second determination unit and a third determination unit.

[0123] Among them, the first determination unit is used to determine whether the first steering wheel theoretical angle and the second steering wheel theoretical angle are valid based on the first available flag bit and the second available flag bit respectively.

[0124] The second judgment unit is used to calculate the angle difference between the first steering wheel theoretical angle and the second steering wheel theoretical angle when both the first steering wheel theoretical angle and the second steering wheel theoretical angle are valid, and to judge whether the angle difference is less than a preset threshold.

[0125] The second determination unit is used to determine the steering wheel control angle by using the first steering wheel theoretical angle or the second steering wheel theoretical angle when the angle difference is less than a preset threshold.

[0126] The third determination unit is used to calculate the differences between the first steering wheel theoretical angle and the second steering wheel theoretical angle and the steering wheel angle sensor angle respectively when the angle difference is greater than or equal to a preset threshold, and determine the steering wheel control angle based on the differences.

[0127] Optionally, in one embodiment of the present application, the second control module further includes: a fourth determining unit and a fifth determining unit.

[0128] Among them, the fourth determination unit is used to determine the steering wheel control angle based on the first steering wheel theoretical angle when the first steering wheel theoretical angle is valid and the second steering wheel theoretical angle is invalid.

[0129] The fifth determination unit is used to determine the steering wheel control angle based on the second steering wheel theoretical angle when the second steering wheel theoretical angle is valid and the first steering wheel theoretical angle is invalid.

[0130] Optionally, in one embodiment of the present application, the second control module further includes: a sixth determination unit.

[0131] Among them, the sixth determination unit is used to execute the vehicle degradation strategy of the vehicle when both the first steering wheel theoretical angle and the second steering wheel theoretical angle are invalid.

[0132] It should be noted that the above explanation of the embodiment of the fault-tolerant control method of the vehicle steer-by-wire system is also applicable to the fault-tolerant control device of the vehicle steer-by-wire system of this embodiment, and will not be repeated here.

[0133] According to the fault-tolerant control device of the vehicle wire-controlled steering system proposed in the embodiment of the present application, after the vehicle is powered on, the steering wheel angle change based on the electrical angle, the reference starting value of the steering wheel angle and the reference starting value of the steering wheel angle corresponding to the electrical angle can be obtained, and then the theoretical value of the steering wheel angle of the vehicle can be estimated, so that when the steering wheel angle sensor fails, the theoretical value of the steering wheel angle can be used to perform fault-tolerant control of the vehicle steering, and the steering wheel angle can be calculated using the motor electrical angle without adding additional redundant components, so as to identify the user's steering angle input to maintain the normal steering operation of the SBW, so that the vehicle can still drive normally according to the user's needs when the steering wheel angle sensor fails, ensuring the user's driving experience and effectively improving the safety performance of the vehicle. Thus, the technical problem that adding a third angle sensor backup in the related art will increase the system cost, volume and weight, and will compress the space of other systems, and the lack of a vehicle degradation strategy that effectively responds to the steering wheel sensor failure working condition will cause the vehicle to be unable to continue driving, which not only affects the user's actual use experience, but also has a large safety hazard.

[0134] Figure 4 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application. The vehicle may include:

[0135] Memory 401 , processor 402 , and a computer program stored in the memory 401 and executable on the processor 402 .

[0136] When the processor 402 executes the program, the fault-tolerant control method of the vehicle steer-by-wire system provided in the above embodiment is implemented.

[0137] Furthermore, the vehicle also includes:

[0138] The communication interface 403 is used for communication between the memory 401 and the processor 402 .

[0139] The memory 401 is used to store computer programs that can be executed on the processor 402 .

[0140] The memory 401 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0141] If the memory 401, the processor 402 and the communication interface 403 are implemented independently, the communication interface 403, the memory 401 and the processor 402 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 4 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0142] Optionally, in a specific implementation, if the memory 401, the processor 402 and the communication interface 403 are integrated on a chip, the memory 401, the processor 402 and the communication interface 403 can communicate with each other through an internal interface.

[0143] The processor 402 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0144] This embodiment also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the fault-tolerant control method of the vehicle steer-by-wire system is implemented.

[0145] An embodiment of the present application also provides a computer program product, including a computer program, which, when executed by a processor, implements the fault-tolerant control method of the vehicle steer-by-wire system provided by an embodiment of the present invention.

[0146] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0147] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0148] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0149] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways as necessary and then storing it in a computer memory.

[0150] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0151] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0152] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0153] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A fault-tolerant control method for a vehicle steer-by-wire system, characterized in that: The following steps are involved: After the vehicle is powered on, obtaining a steering wheel angle change of the vehicle based on an electrical angle; Get the reference starting point value of the steering wheel angle and the reference starting point value of the steering wheel angle corresponding to the electrical angle; A first steering wheel angle theoretical value of the vehicle is estimated based on the steering wheel angle change of the electrical angle, the reference starting point value of the steering wheel angle and the steering wheel angle reference starting point value corresponding to the electrical angle. In the event that a sensor detecting the steering wheel angle fails, fault-tolerant control of the vehicle steering is performed based on the first steering wheel angle theoretical value.

2. The method according to claim 1, characterized in that The step of obtaining a reference starting point value of the steering wheel angle and a reference starting point value of the steering wheel angle corresponding to the electrical angle includes: Obtaining a sensor status of the vehicle; Determining whether the vehicle meets a preset starting angle self-learning condition based on the sensor state; If the vehicle satisfies the starting angle self-learning condition, a reference starting point value of the steering wheel angle and a steering wheel angle reference starting point value of the electrical angle are calculated based on the historical steering wheel angle data of the steering wheel and the steering wheel angle change amount of the electrical angle.

3. The method according to claim 1, characterized in that After estimating the first theoretical steering wheel angle value of the vehicle, the method further includes: estimating a second theoretical steering wheel angle of a steering wheel backup electrical system of the vehicle; Comparing the first theoretical steering wheel angle, the second theoretical steering wheel angle, and the steering wheel angle sensor angle to obtain a quantitative feedback value of the steering wheel angle of the vehicle; A steering wheel control angle of the vehicle is determined based on the quantitative feedback value, so as to perform fault-tolerant control of the vehicle steering based on the steering wheel control angle.

4. The method according to claim 3, characterized in that in, After estimating the first theoretical steering wheel angle value of the vehicle, the method further includes: switching a flag bit of the first theoretical steering wheel angle value to a first available flag bit to allow calling the first theoretical steering wheel angle value; And / or, after estimating the second theoretical steering wheel angle, the method further includes: switching a flag of the second theoretical steering wheel angle value to a second available flag to allow calling the second theoretical steering wheel angle.

5. The method according to claim 4, characterized in that The determining the steering wheel control angle of the vehicle based on the quantitative feedback value comprises: Based on the first available flag bit and the second available flag bit, determining whether the first theoretical steering wheel angle and the second theoretical steering wheel angle are valid respectively; If both the first steering wheel theoretical angle and the second steering wheel theoretical angle are valid, calculating an angle difference between the first steering wheel theoretical angle and the second steering wheel theoretical angle, and determining whether the angle difference is less than a preset threshold; If the angle difference is less than the preset threshold, determining the steering wheel control angle using the first steering wheel theoretical angle or the second steering wheel theoretical angle; If the angle difference is greater than or equal to the preset threshold, the differences between the first steering wheel theoretical angle and the second steering wheel theoretical angle and the steering wheel angle sensor angle are calculated respectively, and the steering wheel control angle is determined based on the differences.

6. The method according to claim 5, characterized in that After determining whether the first theoretical steering wheel angle and the second theoretical steering wheel angle are valid based on the first available flag bit and the second available flag bit, the method further includes: If the first steering wheel theoretical angle is valid and the second steering wheel theoretical angle is invalid, determining the steering wheel control angle based on the first steering wheel theoretical angle; If the second steering wheel theoretical angle is valid and the first steering wheel theoretical angle is invalid, the steering wheel control angle is determined based on the second steering wheel theoretical angle.

7. The method according to claim 5, characterized in that After determining whether the first theoretical steering wheel angle and the second theoretical steering wheel angle are valid based on the first available flag bit and the second available flag bit, the method further includes: If both the first theoretical steering wheel angle and the second theoretical steering wheel angle are invalid, a vehicle degradation strategy for the vehicle is executed.

8. A fault-tolerant control device for a vehicle steer-by-wire system, characterized in that: include: A first acquisition module, configured to acquire a steering wheel angle change of the vehicle based on an electrical angle after the vehicle is powered on; A second acquisition module is used to acquire a reference starting point value of a steering wheel angle and a reference starting point value of a steering wheel angle corresponding to an electrical angle; A control module is used to estimate the theoretical steering wheel angle value of the vehicle based on the steering wheel angle change of the electrical angle, the reference starting point value of the steering wheel angle and the reference starting point value of the steering wheel angle corresponding to the electrical angle, and in the event that the angle sensor detecting the steering wheel fails, perform fault-tolerant control of the vehicle steering based on the theoretical steering wheel angle value.

9. A vehicle, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the fault-tolerant control method for a vehicle steer-by-wire system as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the fault-tolerant control method of a vehicle steer-by-wire system as described in any one of claims 1 to 7.

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