Compensation method and device of steer-by-wire system, vehicle and readable storage medium

Abstract

The invention relates to the technical field of vehicle control, in particular to a compensation method and device of a steer-by-wire system, a vehicle and a readable storage medium. The compensation method comprises the steps that under the condition that a driving working condition is a constant-speed working condition, a hand torque value, downward rotation rack force and a steering wheel angle are obtained; under the conditions that the hand torque value is smaller than or equal to the torque threshold value, the downward rotation rack force is smaller than or equal to the rack force threshold value, and the steering wheel angle is smaller than or equal to the angle threshold value, it is determined that the compensation strategy is a passive compensation strategy; when the driving condition is an acceleration condition or a deceleration condition, acquiring a wheel speed difference between left and right front wheels and a steering wheel angle; under the condition that the wheel speed difference and the steering wheel angle meet set conditions, determining that an active compensation strategy is adopted as a compensation strategy; and compensating the steer-by-wire system according to the passive compensation strategy and the active compensation strategy. The system can adapt to various driving working conditions and is suitable for constant-speed driving, acceleration and deceleration working conditions, and the overall performance and reliability of the system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control, and particularly relates to a compensation method and device for a steer-by-wire system, a vehicle, and a readable storage medium. Background Art

[0002] For the steer-by-wire (SBW) system of an automobile, compared with the traditional automobile steering system, the mechanical connection between the steering wheel and the steering wheel is disconnected in terms of structure, and information communication such as torque and angle of up and down rotation is established in the form of electrical signals. Moreover, the use of a steer-by-wire system can be compatible with autonomous driving technology and better adapt to the trend of intelligent transportation and vehicle networking.

[0003] During the driving process of an automobile, due to the influence of some factors, such as uneven road surfaces, constant crosswinds, tire characteristics, asymmetry of suspension or steering geometry, and non-central vehicle mass center, the vehicle will deviate from the straight path. When the vehicle deviates from the straight path, the driver needs to continuously apply force to the steering wheel to correct the deviation of the vehicle, which is likely to cause driver operation fatigue, affect driving safety, and increase the incidence of traffic accidents.

[0004] In the related art, for the solution to the deviation problem, a deviation compensation method for an electric power steering system is proposed, including: during the driving process of the vehicle, obtaining the state information of the vehicle; the state information includes vehicle speed information, torque information representing whether the vehicle deviates, steering wheel angle, vehicle longitudinal acceleration, and yaw angle. Determining the target state position of the deviation compensation module according to the vehicle state information, and controlling the vehicle to enter the target state position; when in the long-term steering wheel holding state position, performing torque compensation according to the rack force learned by the long-term compensation rack force; when in the activation state position, performing torque compensation after superimposing the short-term compensation rack force and the long-term compensation rack force of the vehicle; when in the waiting state position, performing torque compensation according to the rack force learned by the long-term compensation rack force; when in the exit state position, decreasing the motor torque of the deviation compensation module until the final output is zero.

[0005] In the process of implementing the above embodiments, at least the following problems exist: In the above embodiments, the target state positions of the deviation module are divided into the long-term steering wheel holding state position, the activation state position, the waiting state position, and the exit state position. The quantitative markings of these state positions are not clear, which will lead to frequent start and stop of compensation, affecting the stability of vehicle operation. Moreover, the compensation method depends on rack force learning. For acceleration or deceleration scenarios, only relying on the learned rack force for compensation results in insufficient deviation compensation, thereby affecting the compensation accuracy. Summary of the Invention

[0006] One of the objectives of the present invention is to provide a compensation method for a steer-by-wire system, so as to solve the problems in the prior art that frequent compensation for the steer-by-wire system affects the running stability of the vehicle and the compensation accuracy is low; the second objective is to provide a compensation device for the steer-by-wire system; the third objective is to provide a vehicle; the fourth objective is to provide a readable storage medium.

[0007] To achieve the above objectives, the technical solutions adopted by the present invention are as follows: In some embodiments, a compensation method for a steer-by-wire system is provided, including: obtaining the driving condition of the vehicle; when the driving condition is a constant-speed condition, obtaining the hand torque value, the lower rack force, and the steering wheel angle; when the hand torque value is less than or equal to the torque threshold, the lower rack force is less than or equal to the rack force threshold, and the steering wheel angle is less than or equal to the angle threshold, determining that the compensation strategy adopts a passive compensation strategy; when the driving condition is an acceleration condition or a deceleration condition, obtaining the wheel speed difference between the left and right front wheels and the steering wheel angle; when the wheel speed difference and the steering wheel angle meet the set conditions, determining that the compensation strategy adopts an active compensation strategy; compensating the steer-by-wire system according to the passive compensation strategy and / or the active compensation strategy.

[0008] The compensation method for the steer-by-wire system provided by the present disclosure sets the determination conditions for deviation corresponding to the driving condition according to different driving conditions of the vehicle, and thus can improve the accuracy of identifying the deviation scenario for different driving conditions. Further, corresponding compensation strategies are set for different deviation scenarios, so as to be able to effectively compensate for multiple driving conditions, thereby reducing the operation burden of the driver and avoiding driving fatigue caused by frequent correction of deviation, and thus improving driving safety.

[0009] In this way, compared with the prior art that uses multi-parameter joint determination and does not target the vehicle driving scenario, by identifying the driving condition and setting the deviation determination conditions matching the driving condition according to different driving conditions, the present disclosure improves the coverage of multiple driving conditions. By selecting different parameter combinations for different driving conditions to determine the deviation scenario, the accuracy of identifying the deviation scenario is improved, the response speed is increased, and the false trigger rate is reduced. That is, the present disclosure can adapt to multiple driving conditions, broaden the application scenario of the deviation compensation system, make it not only applicable to constant-speed driving, but also effectively cope with complex conditions such as acceleration and deceleration, and improve the overall performance and reliability of the system. Moreover, compensating the steer-by-wire system according to the passive compensation strategy and / or the active compensation strategy improves the compensation accuracy of the steer-by-wire system and the running stability of the vehicle.

[0010] Optionally, the steps of the passive compensation strategy include: determining the short-term compensation weight corresponding to the current short-term operation cycle according to a preset short-term operation cycle, short-term compensation time calibration quantity, short-term integration ratio calibration quantity, and driver correction confidence; determining the short-term compensation torque of the current short-term operation cycle according to the short-term compensation weight of the current short-term operation cycle, the force transmission ratio from the steering wheel end to the lower rotation motor end, and the hand torque value of the current short-term operation cycle; adding the short-term compensation torque of the current short-term operation cycle to the cumulative value of the historical short-term compensation torque to obtain an updated cumulative short-term compensation torque; and obtaining the target short-term compensation torque according to the updated cumulative short-term compensation torque and the short-term compensation torque exit condition.

[0011] In this embodiment, the short-term compensation weight is calculated according to a preset short-term operation cycle, compensation time calibration quantity, integration ratio calibration quantity, and driver correction confidence, so that the compensation torque can quickly adapt to different driving scenarios and driver intentions. Combining the force transmission ratio and the hand torque value, the compensation torque for each short-term operation cycle is accurately calculated to ensure the accuracy and timeliness of the compensation torque. By adding the current short-term compensation torque to the historical cumulative value, the dynamic accumulation of the compensation torque is realized, the change of the compensation torque is smoothed, and the torque mutation caused by signal fluctuation is reduced. According to the updated cumulative short-term compensation torque and the preset output condition, the final target short-term compensation torque is determined to ensure the stable output of the compensation torque. The short-term compensation strategy in the passive compensation strategy provided by the present disclosure can better adapt to different driving scenarios and driver operation habits by combining the driver correction confidence to adjust the compensation weight and the update mechanism of the cumulative compensation torque, reducing the frequent correction operations required by the driver due to deviation during uniform driving, reducing driving fatigue, and improving driving comfort. The versatility and adaptability of the system are improved.

[0012] Optionally, the steps of obtaining the target short-term compensation torque according to the updated cumulative short-term compensation torque and the short-term compensation torque exit condition include: obtaining the current hand torque value, the current lower rotation rack force, and the current steering wheel angle; and outputting the target short-term compensation torque according to the updated cumulative short-term compensation torque and the short-term compensation exit step threshold when the current hand torque value is less than or equal to the torque threshold, the current lower rotation rack force is less than or equal to the rack force threshold, and the current steering wheel angle is less than or equal to the angle threshold.

[0013] In this embodiment, the current hand torque value, the lower rack force, and the steering wheel angle are obtained in real time to ensure that the compensation strategy can be adjusted according to the latest vehicle state. By setting the thresholds for the hand torque, the lower rack force, and the steering wheel angle, it is accurately determined whether the vehicle is still in a state that requires compensation. Only when all parameters are less than or equal to the thresholds, the compensation torque is output, avoiding unnecessary compensation. Further, a short-term compensation exit step threshold is introduced to ensure a smooth exit process of the compensation torque and avoid a decrease in the driving experience caused by sudden changes in the compensation torque. By setting the short-term compensation exit step threshold, frequent changes in the compensation torque caused by signal fluctuations are avoided, making the compensation torque more stable and reducing discomfort during driving.

[0014] Optionally, the steps of the passive compensation strategy further include: superimposing the target short-term compensation torque on the hand torque value to obtain the hand torque value of the current long-term operation cycle; determining the long-term compensation weight of the current long-term operation cycle according to the preset long-term operation cycle, the long-term compensation time calibration quantity, the long-term integral ratio calibration quantity, and the driver's correction confidence; determining the long-term compensation torque of the current long-term operation cycle according to the long-term compensation weight, the force transmission ratio from the steering wheel end to the lower rotation motor end, and the hand torque value of the current long-term operation cycle; superimposing the long-term compensation torque of the current long-term operation cycle on the cumulative value of the historical long-term compensation torque to obtain the updated long-term compensation cumulative torque; and obtaining the target long-term compensation torque according to the updated long-term compensation cumulative torque and the long-term compensation torque output condition.

[0015] In this embodiment, the hand torque value after short-term compensation is used as the input for long-term compensation to ensure that long-term compensation can be adjusted based on the latest vehicle state. According to the preset long-term operation cycle, the compensation time calibration quantity, the integral ratio calibration quantity, and the driver's correction confidence, the long-term compensation weight is calculated, enabling the compensation torque to better adapt to long-term deviation changes. The current long-term compensation torque is superimposed on the historical cumulative value to smooth the change of the compensation torque and reduce torque mutations caused by signal fluctuations. According to the updated long-term compensation cumulative torque and the preset output conditions, the target long-term compensation torque is dynamically output to ensure the stability and adaptability of the compensation torque. Through the long-term compensation mechanism, the present disclosure further compensates the hand torque value after short-term compensation, can more accurately eliminate the deviation torque, and improve the compensation accuracy. And by accumulating and dynamically adjusting the long-term compensation torque, the instability of the compensation torque caused by signal fluctuations is reduced, and it can better adapt to long-term deviation changes, improving the adaptability and stability of the system.

[0016] Optionally, the steps of the active compensation strategy include: determining a basic compensation torque according to the vehicle speed, the steering wheel angle, and the steering wheel rotation speed; obtaining a first compensation coefficient corresponding to the longitudinal acceleration and a second compensation coefficient corresponding to the front wheel torque; and determining an active compensation torque according to the basic compensation torque, the first compensation coefficient, the second compensation coefficient, the force transmission ratio from the steering wheel end to the lower rotation motor end, and the driver's deviation correction confidence level.

[0017] In this embodiment, the active compensation strategy comprehensively considers multiple parameters such as the vehicle speed, the steering wheel angle, the steering wheel rotation speed, the longitudinal acceleration, and the front wheel torque, determines the first compensation coefficient and the second compensation coefficient, and combines the driver's deviation correction confidence level to adjust the basic compensation torque, ensuring that the compensation torque can be adjusted according to the actual dynamics of the vehicle to improve the deviation compensation accuracy for acceleration and braking conditions and make it more in line with the driver's driving habits.

[0018] Optionally, the steps of determining a basic compensation torque according to the vehicle speed, the steering wheel angle, and the steering wheel rotation speed include: constructing a first calibration relationship of the target rotation speed of the steering wheel corresponding to the vehicle speed and the steering wheel angle; constructing a second calibration relationship of the basic compensation torque corresponding to the vehicle speed and the rotation speed difference, where the rotation speed difference is the absolute value of the difference between the current rotation speed of the steering wheel and the target rotation speed of the steering wheel; and looking up the first calibration relationship and the second calibration relationship according to the vehicle speed and the steering wheel angle to determine the basic compensation torque.

[0019] In this embodiment, by constructing the first calibration relationship between the vehicle speed and the steering wheel angle and the target rotation speed, the target rotation speed of the steering wheel can be determined according to the actual driving state of the vehicle. Calculate the absolute value of the difference between the current rotation speed of the steering wheel and the target rotation speed, and look up the second calibration relationship according to the vehicle speed and the absolute value of the rotation speed difference to determine the basic compensation torque. In this way, by combining the vehicle speed, the steering wheel rotation speed, and the steering wheel angle, and determining the basic compensation torque in combination with the first calibration relationship and the second calibration relationship, the dynamic changes of the vehicle at different vehicle speeds and steering wheel angles can be adapted, the deviation during acceleration and braking can be accurately compensated, and the compensation accuracy can be improved.

[0020] Optionally, the steps of calculating the driver's deviation correction confidence level include: determining a sampling rate, a sample length, and a preset number of detection frequencies, where the detection frequencies corresponding to the preset number are different; collecting the hand torque value and the vehicle speed according to the detection frequency, the sampling rate, and the sample length; calculating the discrete frequency according to the detection frequency, the sampling rate, and the sample length; calculating the recursion coefficient according to the discrete frequency and the sample length; performing iterative calculation according to the recursion coefficient and the collected hand torque value to obtain a weighted ability value; weighting the weighted ability value according to the vehicle speed to obtain a vehicle speed-corrected energy value; and determining the driver's deviation correction confidence level according to the vehicle speed-corrected energy value and the preset mapping relationship.

[0021] In this embodiment, the Goertzel Algorithm is used to perform frequency-domain analysis on the collected hand torque signal, which can effectively detect specific frequency components, thereby accurately identifying the driver's intention to correct deviation. By using the Goertzel Algorithm to analyze the hand torque signal and combining the vehicle speed information to calculate the driver's deviation correction confidence, the low computational complexity ensures the timeliness and accuracy of torque compensation, can accurately identify the driver's intention to correct deviation, adjust the compensation torque, thereby improving the compensation accuracy and adaptability, optimizing the driving experience, and enhancing the stability of the system. Particularly for the steer-by-wire system, the driver's deviation correction confidence is added to the torque calculation part in both the active compensation strategy and the passive compensation strategy to correct the compensation value, which improves the accuracy of the compensation torque and can effectively meet the compensation requirements under signal fluctuations and complex working conditions.

[0022] Optionally, according to the passive compensation strategy and / or the active compensation strategy, the steps of compensating the steer-by-wire system include: after superimposing the active compensation torque and the passive compensation torque, inputting them into the optimized torque controller, and outputting a compensation torque request value; wherein, in the optimized torque controller, the real-time motor torque of the lower-rotating motor is differentiated; the compensation torque request value is output to the lower-rotating motor.

[0023] Optionally, the optimized torque controller includes: placing the differentiation link on the feedback loop to differentiate the real-time motor torque of the lower-rotating motor; the differential equation is: ; where T out (t) is the motor-end torque request value; K p , K i , K d are the proportional, integral, and differential gain values respectively; T act (t) is the real-time motor torque of the lower-rotating motor feedback by the torque sensor; T cmp (t) is the total compensation torque value after superimposing the active compensation torque and the passive compensation torque calculated in the current cycle; σ is the integral reset coefficient.

[0024] In this embodiment, the differential process is placed within the feedback loop to address signal fluctuations in steer-by-wire systems, optimizing the PID controller. This process directly differentiates the real-time motor torque before adding the compensation torque. The resulting torque difference is then used as the controlled variable for proportional-integral control. This allows for faster capture of torque changes, reduces response lag, and ensures the stability of the output torque request, further enhancing the driving experience. Furthermore, an integral reset coefficient is introduced within the integral process. When the torque error exceeds a preset value, the integral term is gradually reset to zero, eliminating the negative effects of integral overshoot and torque fluctuation and preventing overshoot or oscillation caused by integral saturation. The differential process and integral reset mechanism effectively reduce torque fluctuations and improve the stability of the compensation torque. Furthermore, by outputting the compensation torque request to the lower motor, a closed compensation loop is formed, in which the vehicle veers, the driver corrects, the function compensates the lower motor, the upper motor follows the lower motor, and the driver stops correcting. In this way, the delay in the arrival of the compensation torque is avoided, and the influence of the deviation compensation on the handling is compensated. Even if the compensation torque fluctuates frequently, the driver will not feel obvious discomfort.

[0025] Optionally, the step of obtaining the driving condition of the vehicle includes: obtaining the longitudinal acceleration of the vehicle; when the longitudinal acceleration is less than or equal to an acceleration threshold and lasts for a first time period, determining that the vehicle is in a uniform speed condition; when the longitudinal acceleration is greater than the acceleration threshold and lasts for a second time period, determining that the vehicle is in an acceleration condition or a braking condition.

[0026] In this embodiment, the vehicle's operating condition is determined to be constant speed, accelerating, or braking by monitoring longitudinal acceleration and combining its duration. By setting duration thresholds, first and second durations, it is possible to quickly identify operating condition changes and reduce the response lag of the compensation strategy. The compensation strategy is selected based on the identified operating condition, ensuring that it can adapt to different driving scenarios.

[0027] In some embodiments, a compensation device for a steer-by-wire system is provided, comprising: an acquisition module for acquiring the driving condition of a vehicle; a passive compensation mode arbitration module for acquiring a hand torque value, a downward rack force, and a steering wheel angle when the driving condition is a uniform speed condition; determining that a passive compensation strategy is adopted as the compensation strategy when the hand torque value is less than or equal to a torque threshold, the downward rack force is less than or equal to a rack force threshold, and the steering wheel angle is less than or equal to an angle threshold; an active compensation mode arbitration module for acquiring the wheel speed difference and the steering wheel angle of the left and right front wheels when the driving condition is an acceleration condition or a deceleration condition; determining that an active compensation strategy is adopted as the compensation strategy when the wheel speed difference and the steering wheel angle meet set conditions; and a compensation control module for compensating the steer-by-wire system according to the passive compensation strategy and / or the active compensation strategy.

[0028] In some embodiments, a compensation device for a steer-by-wire system is provided, including a processor and a memory storing program instructions. The processor is configured to execute the compensation method for the steer-by-wire system as described in any of the above embodiments when running the program instructions.

[0029] In some embodiments, a vehicle is provided, including: a steer-by-wire system; and a compensation device for the steer-by-wire system as described in any of the above embodiments, where the steer-by-wire system is communicatively connected to the compensation device.

[0030] In some embodiments, a readable storage medium is provided, storing program instructions that, when running, are used to cause a computer to execute the compensation method for the steer-by-wire system as described in any of the above embodiments.

[0031] Advantages of the present invention: (1) Corresponding compensation strategies are adopted for different driving conditions. Specifically, for the condition where the vehicle is driving at a constant speed and drifting, a passive compensation strategy is adopted to solve the problem of driver fatigue caused by frequent correction, improve the driving experience, and reduce safety risks. For the condition where the vehicle drifts during acceleration or braking, an active compensation strategy is adopted to perform active torque compensation on the vehicle from two dimensions of the vehicle's operating parameters and the driver's operations, reducing the driver's operation burden while ensuring the safety of vehicle driving.

[0032] (2) For the driving scenario of the constant-speed condition, the determination factors for determining the drifting scenario include the hand torque value, the lower rack force, and the steering wheel angle. These three parameters are jointly determined. Compared with the related art that determines using parameters such as vehicle speed information, torque information representing whether the vehicle drifts, steering wheel angle, vehicle longitudinal acceleration, and yaw angle, the complexity of drifting determination is reduced, thereby shortening the decision-making cycle and improving the compensation efficiency. Moreover, the determination factor of the present disclosure adopts the lower rack force. As an important parameter of steer-by-wire, the lower rack force has advantages such as high timeliness and good accuracy. By adding a rack force threshold constraint, instantaneous interference caused by road surface bumps can be excluded.

[0033] (3) For the driving scenario of the acceleration or deceleration condition, the determination factors for determining the drifting scenario are the wheel speed difference between the left and right front wheels and the steering wheel angle. Based on the wheel speed difference between the left and right front wheels and the steering wheel angle parameters, the vehicle's acceleration and deceleration drifting conditions are specifically identified. By directly correlating the wheel speed difference, the response delay of the condition is reduced, thereby improving the timeliness of judging the vehicle's acceleration and braking drifting conditions and ensuring reliability. Moreover, through the joint determination of the wheel speed difference between the left and right front wheels and the steering wheel angle, it is possible to avoid misjudging normal steering in a curve as drifting and reduce the false triggering rate.

[0034] (4) By using the Goertzel algorithm to analyze the hand torque signal and combining the vehicle speed information to calculate the driver's deviation correction confidence, the computational complexity is reduced, the timeliness and accuracy of torque compensation are ensured, the driver's deviation correction intention can be accurately identified, the compensation torque can be adjusted, thereby improving the compensation accuracy and adaptability, optimizing the driving experience, and enhancing the stability of the system.

[0035] (5) Specifically for the steer-by-wire system, the driver's deviation correction confidence is added to the torque calculation part in both the active compensation strategy and the passive compensation strategy to correct the compensation value, improving the accuracy of the compensation torque, effectively meeting the compensation requirements under signal fluctuations and complex working conditions, better adapting to different driving scenarios and driver operating habits, reducing the frequent corrections required by the driver due to deviation during uniform driving, reducing driving fatigue, and enhancing driving comfort.

[0036] (6) Regarding the signal fluctuation problem of the steer-by-wire system, the PID controller is optimized by placing the differential link on the feedback loop. After directly differentiating the real-time motor torque and then superimposing the compensation torque, the processed torque difference is used as the controlled quantity, and then proportional-integral control is performed, which can capture the change of torque more quickly, reduce the response lag, thereby ensuring the stability of the output torque request and further enhancing the driving experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a flowchart of the compensation method for the steer-by-wire system provided by an embodiment of the present invention; Figure 2 It is the arbitration coordinate system of the rotational speed difference Δω and the steering wheel angle ψ in the present invention; Figure 3 It is a flowchart of the short-term compensation strategy provided by an embodiment of the present invention; Figure 4 It is a flowchart of the long-term compensation strategy provided by an embodiment of the present invention; Figure 5 It is a flowchart of the active compensation strategy provided by an embodiment of the present invention; Figure 6 It is a schematic diagram of the first calibration relationship of the target rotational speed of the steering wheel corresponding to the vehicle speed and the steering wheel angle in the present invention; Figure 7 It is a schematic diagram of the second calibration relationship of the basic compensation torque corresponding to the vehicle speed and the rotational speed difference in the present invention; Figure 8 It is the first compensation coefficient relationship diagram of the longitudinal acceleration in the present invention; Figure 9 It is the second compensation coefficient relationship diagram of the front wheel torque in the present invention; Figure 10Schematic diagram of the mapping relationship between the energy value and the driver's deviation correction confidence in the present invention; Figure 11 Flowchart of a compensation method for a steer-by-wire system provided by another embodiment of the present invention; Figure 12 System block diagram of a compensation device for a steer-by-wire system provided by an embodiment of the present invention; Figure 13 Structural diagram of a compensation device for a steer-by-wire system provided by an embodiment of the present invention. Detailed implementation manners

[0038] The following will illustrate the implementation manners of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the protection scope of the present invention.

[0039] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0040] In some embodiments, the steer-by-wire system of a vehicle includes a steering wheel assembly, a steering execution assembly, and a main controller. The steering wheel assembly includes a steering wheel, a steering wheel angle sensor, a torque sensor, and a steering wheel return motor. The steering wheel angle sensor is used to detect the steering wheel angle. The torque sensor is used to detect the hand torque of the steering wheel. The main function of the steering wheel assembly is to convert the driver's steering intention into a digital signal by measuring the steering wheel angle and transmit it to the main controller; at the same time, it receives the torque signal sent by the main controller and generates a steering wheel return torque to provide the driver with corresponding road feel information. The steering execution assembly includes a front wheel angle sensor, a lower rotation motor for steering execution, a steering motor controller, and a front wheel steering assembly, etc. The function of the steering execution assembly is to receive the command of the main controller and control the rotation of the steering wheel through the steering motor controller to realize the driver's steering intention. The main controller analyzes and processes the collected signals, discriminates the motion state of the vehicle, sends commands to the steering wheel return motor and the lower rotation motor, controls the operation of the two motors, ensures ideal vehicle response under various working conditions, reduces the driver's compensation task for the change of the vehicle's steering characteristics with the vehicle speed, and reduces the driver's burden. At the same time, the controller can also identify the driver's operation instructions and determine whether the driver's steering operation is reasonable in the current state. When the vehicle is in an unstable state or the driver issues a wrong command, the steer-by-wire system will shield the driver's wrong steering operation and automatically perform stability control to make the vehicle return to a stable state as soon as possible.

[0041] In some embodiments, a compensation device for a steer-by-wire system is provided, including a processor and a memory storing program instructions. The processor is configured to execute the compensation method of the steer-by-wire system as described in any of the above embodiments when running the program instructions. The processor serves as the execution entity of the compensation method of the steer-by-wire system provided in the following embodiments.

[0042] In some embodiments, in combination with Figure 1 as shown, a compensation method for a steer-by-wire system is provided, including: S101, obtaining the driving condition of the vehicle.

[0043] Optionally, the step of obtaining the driving condition of the vehicle includes: obtaining the longitudinal acceleration of the vehicle; when the longitudinal acceleration is less than or equal to the acceleration threshold and lasts for the first duration, determining that the vehicle is in a constant speed condition; when the longitudinal acceleration is greater than the acceleration threshold and lasts for the second duration, determining that the vehicle is in an acceleration condition or a braking condition.

[0044] By monitoring the longitudinal acceleration and combining it with the duration, it is determined whether the vehicle is in a uniform speed, accelerating or braking condition. By setting the duration thresholds, the first duration and the second duration, the change of the condition can be quickly identified, and the response lag of the compensation strategy can be reduced. According to the identified condition, a compensation strategy is selected to ensure that the compensation strategy can adapt to different driving scenarios. Among them, the acceleration threshold, the first duration and the second duration are specifically selected and set according to the configuration parameters of the vehicle and the performance requirements of the vehicle, and no specific limitation is made here.

[0045] S102. In the case where the driving condition is a uniform speed condition, obtain the hand torque value, the downward rotation rack force, and the steering wheel angle.

[0046] Among them, the hand torque of the steering wheel is detected by a torque sensor. The steering wheel angle is detected by a steering wheel angle sensor. The downward rotation rack force is calculated through the torque of the downward rotation motor.

[0047] S103. In the case where the hand torque value is less than or equal to the torque threshold, the downward rotation rack force is less than or equal to the rack force threshold, and the steering wheel angle is less than or equal to the angle threshold, it is determined that the compensation strategy adopts a passive compensation strategy.

[0048] Specifically, for the driving scenario of the uniform speed condition, the determination factors for determining the deviation scenario include the hand torque value, the downward rotation rack force, and the steering wheel angle. These three parameters are jointly determined. Compared with the related art that uses parameters such as vehicle speed information, torque information representing whether the vehicle deviates, steering wheel rotation angle, vehicle longitudinal acceleration, and yaw angle for determination, the complexity of deviation determination is reduced, thereby shortening the decision-making cycle and improving the compensation efficiency. And, the determination factors of the present disclosure adopt the downward rotation rack force. As an important parameter of the steer-by-wire, the downward rotation rack force has the advantages of high timeliness and good accuracy. By adding the rack force threshold constraint, the instantaneous interference caused by road surface bumps can be excluded.

[0049] S104. In the case where the driving condition is an accelerating condition or a decelerating condition, obtain the wheel speed difference between the left and right front wheels and the steering wheel angle.

[0050] S105. In the case where the wheel speed difference and the steering wheel angle meet the set conditions, it is determined that the compensation strategy adopts an active compensation strategy.

[0051] Optionally, the step of determining whether the wheel speed difference and the steering wheel angle meet the set conditions includes: Combine Figure 2As shown, an arbitration coordinate system of rotational speed difference Δω and steering wheel angle ψ is constructed; where the abscissa represents the steering wheel angle and the ordinate represents the rotational speed difference between the left and right front wheels. Exemplarily, it can be set that a left turn (counterclockwise) of the steering wheel angle is positive and a right turn (clockwise) of the steering wheel angle is negative. The rotational speed difference is the difference between the rotational speed of the left front wheel and the rotational speed of the right front wheel. In this way, the first and third quadrants symbolize that the steering wheel angle is opposite to the direction of the expected rotational speed difference; the second and fourth quadrants symbolize that the steering wheel angle is the same as the direction of the expected rotational speed difference. Exemplarily: when the steering wheel turns to the left, the expected rotational speed of the right front wheel should be higher than that of the left front wheel during normal steering, that is, when the steering wheel turns to the left, it is positive, and the rotational speed difference is negative, being in the fourth quadrant. However, if there is understeering or tire slipping, the rotational speed difference value will be very small (close to the Y-axis in the fourth quadrant) or positive (being in the first quadrant), manifested as Figure Four the shaded part shown on the positive X-axis, and the active compensation strategy should be activated. When the steering wheel turns to the right, the situation is similar, manifested as Figure Four the shaded part shown on the negative X-axis.

[0052] Combined with Figure 2 the arbitration coordinate system shown, a critical determination boundary is set, with the critical rotational speed difference Δω e and the critical steering wheel angle ψ １ and ψ ２ as the boundaries to distinguish the shaded parts, specifically including: Area A: ψ > -ψ １ and Δω > 0; Area B: ψ < ψ １ and Δω < 0; Area C: ψ １ ≤ ψ ≤ ψ ２ and Δω ≤ -Δω e , and -ψ2 ≤ ψ ≤ -ψ1 and Δω ≥ Δω e , with a large steering amplitude but insufficient rotational speed difference.

[0053] Combined with the arbitration coordinate system, when the rotational speed difference between the left and right front wheels and the steering wheel angle fall into any one of Area A, Area B, and Area C, the active compensation strategy is activated.

[0054] For the driving scenarios of acceleration or deceleration conditions, the determination factors for judging the pulling-to-one-side scenario are the rotational speed difference between the left and right front wheels and the steering wheel angle. Based on the rotational speed difference between the left and right front wheels and the steering wheel angle parameters, the pulling-to-one-side conditions of the vehicle during acceleration and deceleration are specifically identified. By directly correlating the rotational speed difference, the response delay of the conditions is reduced, thereby improving the timeliness of judging the pulling-to-one-side conditions of the vehicle during acceleration and braking, and ensuring reliability. Moreover, through the combined determination of the rotational speed difference between the left and right front wheels and the steering wheel angle, it is possible to avoid misjudging normal steering in a curve as pulling-to-one-side, reducing the false triggering rate.

[0055] S106, compensate the steer-by-wire system according to the passive compensation strategy and / or the active compensation strategy.

[0056] The compensation method of the steer-by-wire system provided by the present disclosure sets the determination conditions for deviation corresponding to different driving conditions of the vehicle, and thus can improve the accuracy of identifying deviation scenarios for different driving conditions. Further, by distinguishing uniform speed, acceleration, and deceleration conditions and respectively adopting passive compensation and active compensation strategies, effective compensation in a variety of driving scenarios is achieved, thereby reducing the driver's operation burden and avoiding driving fatigue caused by frequent correction of deviation, thus improving driving safety.

[0057] In this way, compared with the solution in the related art that uses multi-parameter joint determination and does not target vehicle driving scenarios, by identifying the driving conditions and setting the deviation determination conditions matching the driving conditions according to different driving conditions, the present disclosure improves the coverage of various driving conditions. By selecting different parameter combinations for different driving conditions to determine the deviation scenario, the accuracy of identifying the deviation scenario is improved, the response speed is increased, and the false trigger rate is reduced. That is, the present disclosure can adapt to various driving conditions, broaden the application scenario of the deviation compensation system, making it applicable not only to uniform speed driving but also effectively coping with complex conditions such as acceleration and deceleration, improving the overall performance and reliability of the system. And, according to the passive compensation strategy and / or the active compensation strategy, the steer-by-wire system is compensated, improving the compensation accuracy of the steer-by-wire system and enhancing the stability of vehicle operation.

[0058] In some embodiments, the passive compensation strategy includes a short-term compensation strategy and a long-term compensation strategy, wherein the short-term compensation strategy is used to handle the deviation that occurs in the vehicle in the short term.

[0059] In some embodiments, as Figure 3 shown, the steps of the short-term compensation strategy include: S301, perform filtering processing on the received hand torque signal.

[0060] Optionally, the step of performing filtering processing includes; filtering out the hand torque signals in the hand torque signal that are less than the torque signal threshold; performing low-pass filtering processing on the filtered hand torque signal at the cut-off frequency. Among them, the torque signal threshold is the minimum hand torque value that needs to be compensated. In this way, by filtering out the hand torque signals less than the torque signal threshold, that is, the dead zone limit value, the purpose is to filter out tiny torque changes. The low-pass filtering is to filter out the influence of high-frequency torque changes on the algorithm.

[0061] S302, determine the short-term compensation weight corresponding to the current short-term operation cycle according to the preset short-term operation cycle, short-term compensation time calibration quantity, short-term integral ratio calibration quantity, and driver correction confidence.

[0062] In this embodiment, according to the short-term operation cycle, the compensation time calibration quantity, the integral ratio calibration quantity, and the driver's deviation correction confidence level, the short-term compensation weight is calculated so that the compensation torque can quickly adapt to different driving scenarios and driver intentions.

[0063] The calculation formula for the short-term compensation weight is:

[0064] where k s is the short-term compensation weight, T is the preset short-term operation cycle, t s is the short-term compensation time calibration quantity, I s is the short-term integral ratio calibration quantity, and μ is the driver's deviation correction confidence level.

[0065] Among them, the preset short-term operation cycle is determined according to the actual operation cycle of the controller of the vehicle-mounted algorithm. The short-term compensation time calibration quantity and the short-term integral ratio calibration quantity are calibrated according to the performance requirements of the vehicle being carried.

[0066] Furthermore, according to the direction of the cumulative value of the historical short-term compensation torque and the direction of the current hand torque signal, the short-term compensation time calibration quantity is calibrated. In the case where the direction of the cumulative value of the historical short-term compensation torque is the same as the direction of the current hand torque signal, the compensation superposition weight is selected. In the case where the direction of the cumulative value of the historical short-term compensation torque is opposite to the direction of the current hand torque signal, the compensation exit weight is selected. Among them, the short-term compensation time calibration quantity corresponding to the compensation superposition weight is less than the short-term compensation time calibration quantity corresponding to the compensation exit weight, so as to ensure that the torque compensation can be based on the driver's intention and flexibly adapt to the driving scenario.

[0067] S303. Determine the short-term compensation torque of the current short-term operation cycle according to the short-term compensation weight of the current short-term operation cycle, the force transmission ratio from the steering wheel end to the lower rotation motor end, and the hand torque value of the current short-term operation cycle.

[0068] In this embodiment, by combining the force transmission ratio and the hand torque value, the compensation torque of each short-term operation cycle is accurately calculated to ensure the accuracy and timeliness of the compensation torque.

[0069] The calculation formula for the short-term compensation torque T se of the current short-term operation cycle is:

[0070] where k s is the short-term compensation weight, r is the force transmission ratio from the steering wheel end to the lower rotation motor end, and θ e is the hand torque value after filtering processing in this cycle.

[0071] S304. Superimpose the short-term compensation torque of the current short-term operation cycle on the cumulative value of the historical short-term compensation torque to obtain the updated cumulative short-term compensation torque.

[0072] In this embodiment, by superimposing the current short-term compensation torque on the historical cumulative value, the dynamic accumulation of the compensation torque is realized, the change of the compensation torque is smoothed, and the torque mutation caused by signal fluctuation is reduced.

[0073] The calculation formula for calculating the updated cumulative short-term compensation torque is: T S =T Pre+ T se ; where, T Pre is the cumulative value of the historical short-term compensation torque, and T se is the short-term compensation torque of this cycle.

[0074] S305. Obtain the target short-term compensation torque according to the updated cumulative short-term compensation torque and the short-term compensation torque exit condition.

[0075] Optionally, the steps of obtaining the target short-term compensation torque according to the updated cumulative short-term compensation torque and the short-term compensation torque exit condition include: obtaining the current hand torque value, the current downward rotating rack force, and the current steering wheel angle; when the current hand torque value is less than or equal to the torque threshold, and the current downward rotating rack force is less than or equal to the rack force threshold, and the current steering wheel angle is less than or equal to the angle threshold, output the target short-term compensation torque according to the updated cumulative short-term compensation torque and the short-term compensation exit step threshold.

[0076] In this embodiment, according to the updated cumulative short-term compensation torque and the preset output conditions, the final target short-term compensation torque is determined to ensure the stable output of the compensation torque. And the current hand torque value, the downward rotating rack force, and the steering wheel angle are obtained in real time to ensure that the compensation strategy can be adjusted according to the latest vehicle state. By setting the thresholds of the hand torque, the downward rotating rack force, and the steering wheel angle, it is accurately judged whether the vehicle is still in a state that needs compensation. Only when all parameters are less than or equal to the thresholds, the compensation torque is output to reduce the false triggering rate. Among them, the hand torque value is less than or equal to the torque threshold to exclude the interference of the driver's active steering. The downward rotating rack force is less than or equal to the rack force threshold to suppress the signal fluctuation caused by road surface bumps. The current steering wheel angle is less than or equal to the angle threshold to ensure that the vehicle is in an approximately straight-ahead state.

[0077] Introduce the short-term compensation exit step threshold to make the exit process of the compensation torque smoother, reduce the jitter amplitude, and avoid the decline of the driving experience caused by the mutation of the compensation torque.

[0078] Specifically, when the current hand torque value is less than or equal to the torque threshold, the current downward rotation rack force is less than or equal to the rack force threshold, and the current steering wheel angle is less than or equal to the angle threshold, further determine whether the updated short-term compensation cumulative torque is less than or equal to the short-term compensation torque threshold, and whether the short-term compensation torque change rate is less than or equal to the short-term compensation gradient threshold. The short-term compensation torque change rate is equal to the short-term compensation torque of the current short-term operation cycle minus the short-term compensation torque obtained in the previous cycle. When the updated short-term compensation cumulative torque is less than or equal to the short-term compensation torque threshold and the short-term compensation torque change rate is less than or equal to the short-term compensation gradient threshold, the updated short-term compensation cumulative torque is output. When the updated short-term compensation cumulative torque is greater than the short-term compensation torque threshold or the short-term compensation torque change rate is greater than the short-term compensation gradient threshold, the short-term compensation torque threshold is output. By setting the short-term compensation torque threshold and the short-term compensation gradient threshold, the short-term compensation frequency is prevented from being too high and affecting the driving feel. The short-term compensation torque threshold and the short-term compensation gradient threshold can be specifically set according to the actual vehicle parameters and operating conditions of the driving vehicle. If any of the current hand torque value, the current downward rotation rack force, and the current steering wheel angle exceeds its corresponding threshold, short-term compensation is cleared in the Ramp mode. After the clearing is completed, the standby state is entered. The calculation formula for clearing the compensation in the Ramp mode is: ; wherein, T Pre is the updated short-term compensation cumulative torque, and T step is the short-term compensation exit step size.

[0079] wherein, T step should be set according to the actual situation of the vehicle. Exemplarily, if the calibration personnel for driving performance believe that the short-term compensation exits too frequently and has an insignificant effect on the actual road surface, then T step should be adjusted smaller, so that the retention time of the short-term compensation torque becomes longer. If T step is too small, the short-term compensation torque cannot be cleared in time according to the driver's intention, resulting in too long a retention time of the compensation torque, which affects the driving feel when changing the driving scenario and has a counterproductive effect. Then T step should be adjusted larger to accelerate the exit speed of the compensation torque.

[0080] In some embodiments, as shown in combination with Figure 4 the steps of the long-term compensation strategy include: S401, superimpose the target short-term compensation torque and the hand torque value, and filter the superimposed hand torque signal to obtain the hand torque value of the current long-term operation cycle.

[0081] By using the hand torque value after short-term compensation as the input for long-term compensation, the response gap is eliminated, enabling the long-term compensation to be adjusted based on the latest vehicle state.

[0082] Optionally, the superimposed hand torque signal is subjected to low-pass filtering at a preset cut-off frequency, and torque signals smaller than the minimum compensation value are filtered out. The value range of the preset cut-off frequency is 20Hz to 100Hz.

[0083] S402. Determine the long-term compensation weight for the current long-term operation cycle according to the preset long-term operation cycle, long-term compensation time calibration quantity, long-term integration ratio calibration quantity, and driver correction confidence level.

[0084] Calculate the long-term compensation weight based on the long-term operation cycle, compensation time calibration quantity, integration ratio calibration quantity, and driver correction confidence level, so that the compensation torque can better adapt to long-term deviation changes.

[0085] Determine the long-term compensation weight k L for the current long-term operation cycle, and the formula is: ; where D is the preset long-term operation cycle, t L is the long-term compensation time calibration quantity, I L is the long-term integration ratio calibration quantity, and μ is the driver correction confidence level.

[0086] Among them, the long-term compensation time calibration quantity t L is 100 to 200 times the short-term compensation time calibration quantity to obtain an accurate and stable long-term compensation torque. The preset long-term operation cycle is determined according to the actual operation cycle of the controller of the vehicle-mounted algorithm. The long-term compensation time calibration quantity is calibrated according to the performance requirements of the vehicle. The long-term integration ratio calibration quantity is calibrated according to the vehicle-mounted algorithm and can be adjusted according to the actual vehicle operation situation. Exemplarily, if it is considered that the long-term compensation torque is superimposed too quickly and the learned torque value is inaccurate, the long-term integration ratio calibration quantity should be adjusted smaller; if it is considered that the long-term compensation torque is superimposed too slowly and it is difficult to play a role, the long-term integration ratio calibration quantity should be adjusted larger.

[0087] S403. Determine the long-term compensation torque for the current long-term operation cycle according to the long-term compensation weight, the force transmission ratio from the steering wheel end to the lower steering motor end, and the hand torque value of the current long-term operation cycle.

[0088] Determine the long-term compensation torque T Le for the current long-term operation cycle, and the calculation formula is: ; where k L is the long-term compensation weight, r is the force transmission ratio from the steering wheel end to the lower steering motor end, and θ elIs the hand torque value for the current long-term operation cycle.

[0089] S404. Superimpose the long-term compensation torque of the current long-term operation cycle on the cumulative value of the historical long-term compensation torque to obtain the updated cumulative long-term compensation torque.

[0090] Superimpose the current long-term compensation torque on the cumulative value of the historical long-term compensation torque, smooth the change of the compensation torque, reduce the torque mutation caused by signal fluctuation, and improve the stability of the compensation torque.

[0091] The calculation formula for obtaining the updated cumulative long-term compensation torque is: T L = T Prel+ T Le ; Wherein, T Prel is the cumulative value of the historical long-term compensation torque, and T Le is the long-term compensation torque of the current long-term operation cycle.

[0092] S405. Obtain the target long-term compensation torque according to the updated cumulative long-term compensation torque and the long-term compensation torque output condition.

[0093] In this embodiment, according to the updated cumulative long-term compensation torque and the preset output condition, the target long-term compensation torque is dynamically output to ensure the stability and adaptability of the compensation torque. The long-term compensation torque output conditions include: determining whether the updated cumulative long-term compensation torque is less than or equal to the long-term compensation torque threshold, and whether the long-term compensation torque change rate is less than or equal to the long-term compensation gradient threshold. The long-term compensation torque change rate is equal to the long-term compensation torque of the current long-term operation cycle minus the long-term compensation torque obtained in the previous cycle. When the updated cumulative long-term compensation torque is less than or equal to the long-term compensation torque threshold and the long-term compensation torque change rate is less than or equal to the long-term compensation gradient threshold, the updated cumulative long-term compensation torque is output. When the updated cumulative long-term compensation torque is greater than the long-term compensation torque threshold or the long-term compensation torque change rate is greater than the long-term compensation gradient threshold, the long-term compensation torque threshold is output. By setting the long-term compensation torque threshold and the long-term compensation gradient threshold, the driving feel is prevented from being affected by too high compensation frequency. The long-term compensation torque threshold and the long-term compensation gradient threshold can be specifically set according to the actual vehicle parameters and operating conditions of the driving vehicle.

[0094] In some embodiments, the active compensation strategy processes the deviation situation generated when the vehicle accelerates and brakes, and receives vehicle speed, hand torque, steering wheel angle, current steering wheel rotation speed, and front wheel torque signals.

[0095] Optionally, as shown in Figure 5 The steps of the active compensation strategy include: S501: Determine a basic compensation torque according to the vehicle speed, the steering wheel angle, and the steering wheel speed.

[0096] The vehicle speed is used to determine the compensation base strength. The steering wheel angle is acquired to identify unexpected yaw, such as one-sided slip. The steering wheel speed is acquired to detect emergency maneuvers.

[0097] Optionally, the step of determining the basic compensation torque based on the vehicle speed, steering wheel angle and steering wheel speed includes: constructing a first calibration relationship of the target speed of the steering wheel corresponding to the vehicle speed and the steering wheel angle; constructing a second calibration relationship of the basic compensation torque corresponding to the vehicle speed and the speed difference, wherein the speed difference is the absolute value of the difference between the current speed of the steering wheel and the target speed of the steering wheel; according to the vehicle speed and the steering wheel angle, checking the first calibration relationship and the second calibration relationship to determine the basic compensation torque.

[0098] In this embodiment, by constructing a first calibration relationship between vehicle speed, steering wheel angle and target speed, the ideal steering rhythm under the current working condition is defined, and the target speed can be adjusted according to the actual driving state of the vehicle, thereby providing a more accurate reference for the calculation of the basic compensation torque. In addition, based on the vehicle speed and speed difference, the basic compensation torque is calculated through the second calibration relationship to quantify the compensation demand for the deviation between the actual and ideal speeds, so that the basic compensation torque can be adjusted according to the actual dynamic characteristics of the vehicle. Among them, the absolute value of the speed difference is processed to uniformly quantify the compensation demand for left / right deviation and reduce the dimension of the calibration relationship. Combined with Figure 6 As shown, the first calibration relationship of the target speed of the steering wheel corresponding to the vehicle speed and the steering wheel angle is constructed. For example, the vehicle speed is breakpoint 1, and the design is: 0Kph, 5Kph, 15Kph, 30Kph, 50Kph, 70Kph, 90Kph, 110Kph. The steering wheel angle is breakpoint 2, and the target speed of the steering wheel for the remaining vehicle speeds is calibrated using linear interpolation to obtain the first calibration relationship. The unit of the target speed is radps, that is, radians per second. Combined with Figure 7 As shown, the absolute value of the difference between the current speed of the steering wheel and the target speed of the steering wheel is calculated as the speed difference. A second calibration relationship of the basic compensation torque corresponding to the vehicle speed and the speed difference is constructed. For example, in combination with Figure 7 As shown, the design breakpoint 1 is the vehicle speed, breakpoint 2 is the target speed difference, and the output is the basic compensation torque.

[0099] S502 : Obtain a first compensation coefficient corresponding to the longitudinal acceleration and a second compensation coefficient corresponding to the front wheel torque.

[0100] By introducing multiple parameters such as vehicle speed, steering wheel angle, steering wheel rotation speed, longitudinal acceleration, and front wheel torque, the dynamic characteristics of the vehicle under acceleration and braking conditions are comprehensively considered, thereby improving the compensation accuracy. By setting the first compensation coefficient, the influence degree of the vehicle pitching attitude is determined. By setting the second compensation system, the tire grip state is determined, and then the first compensation coefficient and the second compensation coefficient are used to adjust the basic compensation torque to ensure that the compensation torque can be adjusted according to the actual dynamic characteristics of the vehicle.

[0101] In this embodiment, for the vehicle running deviation during acceleration and deceleration, combined with Figure 8 as shown, a first compensation coefficient relationship diagram corresponding to the longitudinal acceleration is designed. And combined with Figure 9 as shown, a second compensation coefficient relationship diagram of the front wheel torque is designed. By designing the first compensation coefficient relationship diagram corresponding to the longitudinal acceleration and the second compensation coefficient relationship diagram corresponding to the front wheel torque, according to the driving characteristics of the vehicle, it provides a suitable compensation coefficient for accurately identifying the running deviation condition, improves the torque compensation accuracy, and compared with real-time operation, it improves the coefficient calculation speed, optimizes the software operation efficiency, and reduces the delay of torque compensation.

[0102] S503. Determine the active compensation torque according to the basic compensation torque, the first compensation coefficient, the second compensation coefficient, the force transmission ratio from the steering wheel end to the lower rotating motor end, and the driver's deviation correction confidence.

[0103] By introducing the driver's deviation correction confidence, the driver's operation intention is incorporated into the calculation of the compensation torque, further optimizing the compensation effect and making it more in line with the driver's driving habits. By combining the driver's deviation correction confidence, the active compensation strategy can better reflect the driver's operation intention, reduce the driving discomfort caused by improper compensation, and improve the driving experience.

[0104] The calculation formula for determining the active compensation torque T l is: ; where K l is the first compensation coefficient corresponding to the longitudinal acceleration, K w is the second compensation coefficient corresponding to the front wheel torque, F b is the basic compensation torque, r is the force transmission ratio from the steering wheel end to the lower rotating motor end, and μ is the driver's deviation correction confidence.

[0105] In some embodiments, the steps of calculating the driver's correction confidence include: determining a sampling rate, a sample length, and a preset number of detection frequencies, where the detection frequencies corresponding to the preset number are different; and collecting hand torque values and vehicle speeds according to the detection frequencies, the sampling rate, and the sample length; calculating a discrete frequency according to the detection frequencies, the sampling rate, and the sample length; calculating a recursion coefficient according to the discrete frequency and the sample length; performing iterative calculation according to the recursion coefficient and the collected hand torque values to obtain a weighted ability value; weighting the weighted ability value according to the vehicle speed to obtain a vehicle speed corrected energy value; and determining the driver's correction confidence according to the vehicle speed corrected energy value and a preset mapping relationship.

[0106] In this embodiment, it is considered that when the vehicle is driving on the road surface, the tires will continuously receive road surface excitation, causing the lower rotation rack force signal to fluctuate, and the disturbance frequency is about 15 Hz. This disturbance signal will be fed back to the hand torque signal along with the up and down rotation following function, causing the hand torque signal to also generate this disturbance. When the driver operates the steering wheel to correct the vehicle, the disturbance frequency will be significantly reduced. In response to the driver's correction behavior, the present disclosure corrects the compensation torque through the driver's correction confidence, enabling it to adapt to different driving scenarios and driver operating habits, and improving the adaptability of the system.

[0107] Optionally, the steps of estimating the driver's correction confidence using the Goertzel algorithm include: Determining signal processing parameters: setting a sampling rate (R), a sample length (N), and a preset number of detection frequencies (δ), where the value range of the preset number is from 1 to 3. By selecting multiple different frequencies for detection to improve detection accuracy, the value range of the detection frequency is from 15 Hz to 20 Hz. The sampling rate R refers to the number of sampling points per second; the sample length N refers to the number of sampling points at which an evaluation is performed every few.

[0108] Collecting hand torque and vehicle speed signals: continuously collecting hand torque and vehicle speed according to the set sampling rate. The hand torque value can reflect the operating force of the driver on the steering wheel and is a key signal for judging the driver's correction intention. The vehicle speed is used to adjust the magnitude of the compensation torque because the driver's operating habits and the dynamic characteristics of the vehicle are different at different vehicle speeds.

[0109] Calculating the discrete frequency K according to the detection frequencies, the sampling rate, and the sample length, and the calculation formula is: . Rounding K to the nearest integer to obtain the integer value of the discrete frequency. The discrete frequency K is used to determine the frequency resolution in signal processing and is the basis for subsequent recursion coefficient calculation.

[0110] Calculating the recursion coefficient C according to the discrete frequency and the sample length, and the calculation formula is: , the recursive coefficient C is used for subsequent iterative calculations and is one of the core parameters of the Goertzel algorithm for extracting the energy of specific frequency components.

[0111] According to the recursive coefficient and the collected hand torque values, the steps of iteratively calculating the weighted energy value by traversing N sample points include: initializing the iterative variables: x(n - 1)=0, x(n)=0, x(n + 1)=0, y(n)=0.

[0112] For each sampling point n (from 1 to N), iterative calculations are performed using the recursive formula: x(n - 1)=C×x(n)-x(n + 1)+T HW ; where T HW is the hand torque value at the nth sampling point.

[0113] x(n + 1)=x(n); x(n)=x(n - 1); y(n)=x(n) 2 +x(n + 1) 2 -C×x(n)×x(n + 1).

[0114] Taking the number of detection frequencies as 3 as an example, the calculated energy values y1, y2, y3 are weighted and combined into y m . By iteratively calculating the energy value for extracting the specific frequency component in the hand torque signal, it reflects the intensity of the driver's corrective behavior.

[0115] The steps of obtaining the vehicle speed corrected energy value p by weighting the weighted energy value according to the vehicle speed include: according to the vehicle speed, looking up the corresponding weight coefficient w from the preset vehicle speed weight table. Using the formula p = y m ×w to calculate the vehicle speed corrected energy value p. The vehicle speed corrected energy value takes into account the influence of the vehicle speed on the driver's operation, making the energy value more in line with the actual driving scenario. The vehicle speed weight table can set the mapping relationship table between different vehicle speed intervals and the corresponding weight coefficients, and the specific setting can be specifically set according to the performance parameters of the specific vehicle, which will not be elaborated here one by one.

[0116] The steps of determining the driver's corrective confidence level according to the vehicle speed corrected energy value and the preset mapping relationship: Combining Figure 10 as shown, the constructed mapping relationship between the energy value and the driver's corrective confidence level. According to the obtained vehicle speed corrected energy value, combined with the mapping relationship between the energy value and the driver's corrective confidence level, the corresponding driver's corrective confidence level is retrieved. By constructing the mapping relationship between the energy value and the driver's corrective confidence level, the energy value is correspondingly converted into a compensation torque coefficient, which is designed based on the actual vehicle debugging experience.

[0117] In the embodiments of the present disclosure, by increasing the driver's deviation correction confidence, the driver's deviation correction confidence is used to reflect the credibility of the driver's deviation correction behavior, and is used to adjust the magnitude of the compensation torque to ensure that the compensation torque more conforms to the actual intention of the driver. By calculating the driver's deviation correction confidence, adjusting the magnitude of the compensation torque, and correcting the weighted energy value according to the vehicle speed, it is ensured that the compensation torque can maintain consistency and accuracy at different vehicle speeds.

[0118] In some embodiments, as shown in Figure 11 a compensation method for a steer-by-wire system is provided, including: S1101, obtaining the driving condition of the vehicle.

[0119] S1102, when the driving condition is a constant-speed condition, obtaining the hand torque value, the lower-rotating rack force, and the steering wheel angle.

[0120] S1103, when the hand torque value is less than or equal to the torque threshold, the lower-rotating rack force is less than or equal to the rack force threshold, and the steering wheel angle is less than or equal to the angle threshold, determining that the compensation strategy adopts a passive compensation strategy.

[0121] S1104, when the driving condition is an acceleration condition or a deceleration condition, obtaining the wheel speed difference between the left and right front wheels and the steering wheel angle.

[0122] S1105, when the wheel speed difference and the steering wheel angle meet the set conditions, determining that the compensation strategy adopts an active compensation strategy.

[0123] S1106, after superimposing the active compensation torque and the passive compensation torque, inputting them into the optimized torque controller, and outputting a compensation torque request value; wherein, in the optimized torque controller, the real-time motor torque of the lower-rotating motor is differentiated.

[0124] S1107, outputting the compensation torque request value to the lower-rotating motor.

[0125] Optionally, the optimized torque controller includes: placing the differentiation link on the feedback loop and differentiating the real-time motor torque of the lower-rotating motor; The differential equation is: ; where T out (t) is the motor-end torque request value; K p , K i , K d are the proportional, integral, and differential gain values respectively; T act (t) is the real-time motor torque of the lower-rotating motor fed back by the torque sensor; T cmp (t) is the total compensation torque value after superimposing the active compensation torque and the passive compensation torque calculated in the current cycle; σ is the integral reset coefficient.

[0126] In this embodiment, considering that the road conditions are very complex during vehicle driving, which can easily cause high-frequency disturbances in the motor torque signal feedback by the actuator, the present disclosure adopts a differential lead strategy to optimize the torque controller, that is, the differential link is placed on the feedback loop to differentiate the measured motor torque to replace the traditional PID differential process for the error. The present invention integrates the compensation torque and outputs it to the lower-rotating motor end, ensuring the stability of the function and eliminating the negative impact of the deviation compensation on the driver's feel. For the problem of unstable motor torque output that may occur in a steer-by-wire vehicle, the differential lead strategy is adopted: after differentiating the current motor torque, the compensation torque is superimposed, and the processed torque difference is used as the controlled quantity, and then proportional-integral control is performed. In the integral link, this module adopts an integral reset and dead zone control strategy to eliminate the negative impact brought by integral overshoot and torque fluctuation.

[0127] Optionally, the step of superimposing the active compensation torque and the passive compensation torque includes: total compensation torque = active compensation torque × first weight + passive compensation torque × second weight, and the first weight and the second weight are calibrated according to the vehicle state parameters or the driver's intention focused on by the actual vehicle carried, according to the performance requirements. Paying attention to the vehicle state parameters increases the weight of the active compensation torque, and paying attention to the driver's deviation correction intention increases the weight of the passive compensation torque.

[0128] Optionally, when the controlled quantity T cmp (t) exceeds the preset maximum value e max , σ is gradually set to 0 in the form of Ramp, and when the controlled quantity is less than the preset maximum value, σ is set to 1. The specific formula is as follows: ; wherein, the preset maximum value e max的 has a calibration range of 0.6 N·m to 0.8 N·m, and the specific value is set according to the performance requirements of the actual vehicle carried.

[0129] In addition, when the controlled quantity T cmp (t) is less than the preset dead zone limit value, it indicates that the torque difference is small, and the current sampling result is not included in the integral calculation to avoid calculation errors in the motor torque request value caused by frequent fluctuations of the motor torque and problems such as uneven feel for the driver. In this way, the integral link is used to eliminate the steady-state error. And the integral saturation reset step is used to avoid excessive accumulation of the integral term in the case where the system cannot respond, resulting in too large overshoot or oscillation, which can improve the dynamic response of the system, reduce the recovery time, and improve the stability. The ramp reset method is used to avoid abnormal vehicle steering caused by torque mutation.

[0130] Among them, the preset dead zone limit calibration range is 0.1 N·m to 0.25 N·m, and specific settings can be made according to the performance requirements of the vehicle equipped with the actual vehicle.

[0131] Exemplarily, during the vehicle driving process, due to the influence of factors such as constant crosswind, road surface inclination, abnormal tire pressure, and tire side slip, the heading angle of the vehicle deviates, and the driver outputs a hand torque to correct the deviation. By using the compensation method provided in the present disclosure, the driving conditions of the vehicle are obtained, and the corresponding operating parameters and compensation strategies are determined according to the driving conditions of the vehicle. In the uniform speed condition, the hand torque value, the lower rotation rack force, and the steering wheel angle are obtained, and the compensation strategy adopts an active compensation strategy; in the acceleration condition or the deceleration condition, the wheel speed difference between the left and right front wheels and the steering wheel angle are obtained, and the determined compensation strategy adopts an active compensation strategy. Then, after superimposing the active compensation torque and the passive compensation torque, it is input into the optimized torque controller, and a compensation torque request value is output; among them, in the optimized torque controller, the real-time motor torque of the lower rotation motor is differentiated; the compensation torque request value is output to the lower rotation motor. The lower rotation motor responds and executes the torque request value to correct the vehicle heading angle. At the same time, the angle closed-loop control system of the main controller responds to the angle difference between the steering wheel return motor and the lower rotation motor, outputs a hand feeling compensation torque request, the steering wheel return motor responds, executes the hand feeling compensation torque request, corrects the hand torque output by the driver, and forms a compensation closed-loop in which the vehicle runs off course, the driver corrects, the torque compensation lower rotation motor, and the upper rotation steering wheel return motor follows the lower rotation motor to compensate for the driver's hand torque.

[0132] In some embodiments, in combination with Figure 12 As shown, a compensation device 1200 for a steer-by-wire system is provided, including: an acquisition module 1201 for acquiring the driving conditions of the vehicle; a passive compensation mode arbitration module 1202 for acquiring the hand torque value, the lower rotation rack force, and the steering wheel angle when the driving condition is a uniform speed condition; and determining that the compensation strategy adopts a passive compensation strategy when the hand torque value is less than or equal to the torque threshold, the lower rotation rack force is less than or equal to the rack force threshold, and the steering wheel angle is less than or equal to the angle threshold; an active compensation mode arbitration module 1203 for acquiring the wheel speed difference between the left and right front wheels and the steering wheel angle when the driving condition is an acceleration condition or a deceleration condition; and determining that the compensation strategy adopts an active compensation strategy when the wheel speed difference and the steering wheel angle meet the set conditions; a compensation control module 1204 for compensating the steer-by-wire system according to the passive compensation strategy and / or the active compensation strategy.

[0133] Optionally, the acquisition module 1201 is used to acquire signals such as hand torque, steering wheel angle, vehicle speed, longitudinal acceleration, lateral acceleration, yaw rate, front wheel torque, left front wheel speed, and right front wheel speed, which are used to determine the current driving state of the vehicle and whether it is deviating from the straight path. Among them, the hand torque and the steering wheel angle are not only used for state judgment but also for calculating the compensation torque value. The yaw rate value only serves as an important condition for judging the driving state of the vehicle.

[0134] Optionally, the compensation device further includes a signal diagnosis module 1205, which is used to diagnose the validity of the signals corresponding to the parameters acquired by the acquisition module. If the diagnosis result is abnormal, the compensation function is not triggered, and the error information is fed back to the vehicle controller. If the diagnosis result is normal, the hand torque, steering wheel angle, vehicle speed, longitudinal acceleration, lateral acceleration, yaw rate, left front wheel speed, right front wheel speed, steering wheel speed, and lower rack force are input to the arbitration unit for arbitration. The signal diagnosis here includes signal communication diagnosis. For example, signal communication anomalies include, but are not limited to, sensor failures, CRC (Cyclic Redundancy Check) check failures, data runaway caused by unexpected problems, etc.; and for signals such as vehicle speed and steering wheel angle that require received signal values and signal valid bits, the abnormality is directly judged through the valid bits. The output function validity is abnormal, and it is cyclically detected. If the result value is normal, it jumps to the standby state. The standby state refers to an intermediate state of the algorithm. When the signal diagnosis is normal and the vehicle is not in a state of deviating from the straight path, the algorithm is in the standby state.

[0135] In some embodiments, in combination with Figure 13 As shown, a compensation device 1300 for a steer-by-wire system is provided, which includes a processor 1310 and a memory 1320 storing program instructions. Optionally, the device 1300 may further include a communication interface 1330 and a bus 1340. Among them, the processor 1310, the communication interface 1330, and the memory 1320 can complete mutual communication through the bus 1340. The communication interface 1330 can be used for information transmission. The processor 1310 can call the logical instructions in the memory 1320 to execute the compensation method for the steer-by-wire system as described in any of the above embodiments.

[0136] In addition, when the logical instructions in the above-mentioned memory 1320 are implemented in the form of a software functional unit and sold or used as an independent product, they can be stored in a computer-readable storage medium.

[0137] The memory 1320, being a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as the program instructions / modules corresponding to the methods in the embodiments of the present disclosure. The processor 1300 executes functional applications and data processing by running the program instructions / modules stored in the memory 1320, that is, implements the compensation method for the steer-by-wire system in the above embodiments.

[0138] The memory 1320 may include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created according to the use of the terminal device, etc. In addition, the memory 1320 may include high-speed random access memory and may also include non-volatile memory.

[0139] In some embodiments, a vehicle is provided, including: a steer-by-wire system; and a compensation device for the steer-by-wire system as described in any of the above embodiments, where the steer-by-wire system is communicatively connected to the compensation device.

[0140] The embodiments of the present disclosure provide a computer-readable storage medium storing computer-executable instructions, and the computer-executable instructions are configured to execute the compensation method for the steer-by-wire system.

[0141] The technical solution of the embodiments of the present disclosure can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes one or more instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiments of the present disclosure. The foregoing storage medium may be a non-transitory storage medium, such as: a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk, or an optical disc, etc., which are various media that can store program codes.

[0142] The above description and the accompanying drawings fully illustrate the embodiments of the present disclosure, enabling those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, process, and other changes. Embodiments merely represent possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terms used in this application are only for describing embodiments and do not limit the claims. As used in the description of embodiments and claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to also include the plural forms. Similarly, as used in this application, the term "and / or" refers to any and all possible combinations of one or more of the associated listed items. Additionally, when used in this application, the term "comprise" and its variants "comprises" and / or "comprising" etc. mean the presence of the stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or groupings of these. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of additional identical elements in the process, method, or device comprising the element. In this article, what each embodiment focuses on can be the differences from other embodiments, and the same or similar parts between various embodiments can be referred to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method parts disclosed in the embodiments, the relevant parts can refer to the description of the method parts.

[0143] Those skilled in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner can depend on the specific application and design constraints of the technical solution. The skilled person can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the embodiments of the present disclosure. The skilled person can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0144] In the embodiments disclosed herein, the disclosed methods, products (including but not limited to devices, equipment, etc.) can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units can be merely a logical function division. In actual implementation, there can be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Additionally, the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect coupling or communication connection of devices or units can be in electrical, mechanical or other forms. The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to implement this embodiment. Additionally, in the embodiments of the present disclosure, the various functional units can be integrated in one processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0145] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram can represent a module, a program segment, or a part of code that contains one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions marked in the blocks can also occur in a different order than that marked in the accompanying drawings. For example, two consecutive blocks can actually be executed substantially in parallel, and they can sometimes be executed in the reverse order, which can depend on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks can also occur in a different order than that disclosed in the description. Sometimes, there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the reverse order, which can depend on the functions involved. Each block in the block diagram and / or flowchart, as well as the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions. The above embodiments are merely preferred embodiments given to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art of this technology on the basis of the present invention are all within the protection scope of the present invention.

Claims

1. A compensation method for a steer-by-wire system, characterized in that, Including: Obtain the driving condition of the vehicle; When the driving condition is a constant speed condition, obtain the hand torque value, the downward rotation rack force, and the steering wheel angle; When the hand torque value is less than or equal to the torque threshold, the downward rotation rack force is less than or equal to the rack force threshold, and the steering wheel angle is less than or equal to the angle threshold, determine that the compensation strategy adopts a passive compensation strategy; When the driving condition is an acceleration condition or a deceleration condition, obtain the wheel speed difference between the left and right front wheels and the steering wheel angle; when the wheel speed difference and the steering wheel angle meet the set conditions, determine that the compensation strategy adopts an active compensation strategy; Compensate the steer-by-wire system according to the passive compensation strategy and / or the active compensation strategy.

2. The compensation method according to claim 1, characterized in that The steps of the passive compensation strategy include: Determine the short-term compensation weight corresponding to the current short-term operation cycle according to the preset short-term operation cycle, the short-term compensation time calibration quantity, the short-term integral ratio calibration quantity, and the driver correction confidence; Determine the short-term compensation torque of the current short-term operation cycle according to the short-term compensation weight of the current short-term operation cycle, the force transmission ratio from the steering wheel end to the downward rotation motor end, and the hand torque value of the current short-term operation cycle; Superimpose the short-term compensation torque of the current short-term operation cycle on the cumulative value of the historical short-term compensation torque to obtain the updated short-term compensation cumulative torque; Obtain the target short-term compensation torque according to the updated short-term compensation cumulative torque and the short-term compensation torque exit condition.

3. The compensation method according to claim 2, characterized in that The steps of obtaining the target short-term compensation torque according to the updated short-term compensation cumulative torque and the short-term compensation torque exit condition include: Obtain the current hand torque value, the current downward rotation rack force, and the current steering wheel angle; When the current hand torque value is less than or equal to the torque threshold, the current downward rotation rack force is less than or equal to the rack force threshold, and the current steering wheel angle is less than or equal to the angle threshold, output the target short-term compensation torque according to the updated short-term compensation cumulative torque and the short-term compensation exit step threshold.

4. The compensation method according to claim 2, characterized in that, The steps of the passive compensation strategy further include: Superimpose the target short-term compensation torque on the hand torque value to obtain the hand torque value of the current long-term operation cycle; Determine the long-term compensation weight of the current long-term operation cycle according to the preset long-term operation cycle, the long-term compensation time calibration quantity, the long-term integral ratio calibration quantity, and the driver correction confidence; Determine the long-term compensation torque of the current long-term operation cycle according to the long-term compensation weight, the force transmission ratio from the steering wheel end to the downward rotation motor end, and the hand torque value of the current long-term operation cycle; Superimpose the long-term compensation torque of the current long-term operation cycle on the cumulative value of the historical long-term compensation torque to obtain the updated long-term compensation cumulative torque; Obtain the target long-term compensation torque according to the updated long-term compensation cumulative torque and the long-term compensation torque output condition.

5. The compensation method according to claim 1, characterized in that, The steps of the active compensation strategy include: Determine the basic compensation torque according to the vehicle speed, the steering wheel angle, and the steering wheel rotation speed; Obtain the first compensation coefficient corresponding to the longitudinal acceleration and the second compensation coefficient corresponding to the front wheel torque; Determine the active compensation torque according to the basic compensation torque, the first compensation coefficient, the second compensation coefficient, the force transmission ratio from the steering wheel end to the downward rotation motor end, and the driver correction confidence.

6. The compensation method according to claim 5, wherein, The steps for determining the basic compensation torque according to vehicle speed, steering wheel angle, and steering wheel rotation speed include: Constructing a first calibration relationship of the target rotation speed of the steering wheel corresponding to the vehicle speed and the steering wheel angle; Constructing a second calibration relationship of the basic compensation torque corresponding to the vehicle speed and the rotation speed difference, where the rotation speed difference is the absolute value of the difference between the current rotation speed of the steering wheel and the target rotation speed of the steering wheel; Querying the first calibration relationship and the second calibration relationship according to the vehicle speed and the steering wheel angle to determine the basic compensation torque.

7. The compensation method according to any one of claims 2 to 5, characterized in that The steps for calculating the driver's deviation correction confidence level include: Determining the sampling rate, the sample length, and a preset number of detection frequencies, where the detection frequencies corresponding to the preset number are different; Collecting the hand torque value and the vehicle speed according to the detection frequency, the sampling rate, and the sample length; Calculating the discrete frequency according to the detection frequency, the sampling rate, and the sample length; Calculating the recursion coefficient according to the discrete frequency and the sample length; Performing iterative calculation according to the recursion coefficient and the collected hand torque value to obtain the weighted ability value; Weighting the weighted ability value according to the vehicle speed to obtain the vehicle speed corrected energy value; Determining the driver's deviation correction confidence level according to the vehicle speed corrected energy value and the preset mapping relationship.

8. The compensation method according to any one of claims 1 to 5, characterized in that The steps for compensating the steer-by-wire system according to the passive compensation strategy and / or the active compensation strategy include: After superimposing the active compensation torque and the passive compensation torque, inputting them into the optimized torque controller, and outputting the compensation torque request value; where, in the optimized torque controller, the real-time motor torque of the lower rotation motor is differentiated; Outputting the compensation torque request value to the lower rotation motor.

9. The compensation method according to claim 8, wherein The optimized torque controller includes: Placing the differentiation link on the feedback loop to differentiate the real-time motor torque of the lower rotation motor; The differential equation is: ； Among them, T out (t) is the torque request value at the motor end; K p , K i , K d are the proportional, integral, and differential gain values respectively; T act (t) is the real-time motor torque of the lower rotating motor fed back by the torque sensor; T cmp (t) is the total compensation torque value after superimposing the active compensation torque and the passive compensation torque calculated in the current cycle; σ is the integral clearing coefficient.

10. The compensation method according to any one of claims 1 to 5, characterized in that, The steps for obtaining the driving condition of the vehicle include: Obtaining the longitudinal acceleration of the vehicle; When the longitudinal acceleration is less than or equal to the acceleration threshold and lasts for the first duration, determining that the vehicle is in a constant speed condition; When the longitudinal acceleration is greater than the acceleration threshold and lasts for the second duration, determining that the vehicle is in an acceleration condition or a braking condition.

11. A compensation device for a steer-by-wire system, characterized in that, Including: An acquisition module for obtaining the driving condition of the vehicle; A passive compensation mode arbitration module for obtaining the hand torque value, the lower rotation rack force, and the steering wheel angle when the driving condition is a constant speed condition; When the hand torque value is less than or equal to the torque threshold, the lower rotation rack force is less than or equal to the rack force threshold, and the steering wheel angle is less than or equal to the angle threshold, determining that the compensation strategy adopts the passive compensation strategy; An active compensation mode arbitration module for obtaining the wheel speed difference between the left and right front wheels and the steering wheel angle when the driving condition is an acceleration condition or a deceleration condition; when the wheel speed difference and the steering wheel angle meet the set conditions, determining that the compensation strategy adopts the active compensation strategy; A compensation control module for compensating the steer-by-wire system according to the passive compensation strategy and / or the active compensation strategy.

12. A compensation device for a steer-by-wire system, characterized in that, Including a processor and a memory storing program instructions, the processor is configured to execute the compensation method of the steer-by-wire system according to any one of claims 1 to 10 when running the program instructions.

13. A vehicle, characterized in that, Including: A steer-by-wire system; The compensation device of the steer-by-wire system according to claim 11 or 12, wherein the steer-by-wire system is communicatively connected to the compensation device.

14. A readable storage medium stores program instructions, characterized in that, When running, the program instructions are used to cause a computer to execute the compensation method of the steer-by-wire system according to any one of claims 1 to 10.

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