A control method and control system of a steer-by-wire system

Abstract

The application provides a control method and a control system of a steer-by-wire system. The method comprises the following steps: constructing a steering system dynamics equation based on a target front wheel running parameter, a configuration parameter and a target damping coefficient of a magneto-rheological damper in a shimmy instability mode, wherein the product of the target damping coefficient and a front wheel rotation speed is equal to the product of an initial damping coefficient of the magneto-rheological damper and a magneto-rheological damper current; obtaining a characteristic equation and all characteristic value expressions based on the steering system dynamics equation; obtaining real-time values of the target front wheel running parameter, a value of the configuration parameter, a magneto-rheological damper current real-time value and a value of the initial damping coefficient; obtaining real part values of all characteristic values of the characteristic value expressions based on the obtained values; and adjusting the magneto-rheological damper current real-time value until the real part values of all characteristic values are not greater than zero to obtain a value of the target damping coefficient, if there is at least one characteristic value whose real part value is greater than zero. The method according to the application can solve the front wheel shimmy problem.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of vehicles, and particularly relates to a control method and a control system of a steer-by-wire system. BACKGROUND

[0002] The steering system of a traditional vehicle has problems such as low flexibility, long transmission mechanism, and difficulty in maintenance, and the front wheel steering mechanism occupies a large space, which hinders the application of a wheeled vehicle in more scenarios.

[0003] Compared with a traditional steering system, the steer-by-wire active steering technology cancels the mechanical connection between a steering wheel and a steering mechanism, and uses an electric control system to replace a steering actuator. Therefore, the steer-by-wire system can freely design the steering angle response characteristics and torque response characteristics of the steering wheel to the front wheels of the vehicle, which is of key significance to improving driving comfort and future unmanned driving.

[0004] In addition, the full electrification of future vehicles has become a development trend, and more and more mechanisms on the chassis are replaced by electric control systems. Integrated electric wheels also appear on many concept vehicles. A single wheel can realize steer-by-wire driving, steer-by-wire braking, and steer-by-wire steering, and can realize 360° free steering.

[0005] At present, all integrated electric wheels using a kingpin steering mechanism, and the kingpin is perpendicular to the ground. If the wheel positioning is not suitable, the deceleration mechanism has a gap, or the damping force of the steering system is too small, the front wheel will face the problem of shimmy. It is usually manifested as the continuous angular vibration of the front wheel assembly around its kingpin axis. In the absence of external intervention, the shimmy movement of the front wheel of the vehicle will not self-decay or disappear. The problem of front wheel shimmy not only affects the driving experience, but also can cause serious traffic accidents. Therefore, the kingpin steering mechanism needs to solve the problem of shimmy before it is widely used. SUMMARY

[0006] The present application aims to at least solve one of the technical problems in the related art. To this end, the present application provides a control method and a control system of a steer-by-wire system, and the main purpose is to solve the problem of front wheel shimmy.

[0007] According to a first aspect of the present application, a control method of a steer-by-wire system is provided, the steer-by-wire system being arranged on a target front wheel of a vehicle, the steer-by-wire system comprising a decelerator and a magneto-rheological damper, the magneto-rheological damper being arranged on an output shaft of the decelerator, and the control method comprising:

[0008] The steering system dynamic equations are constructed based on the driving parameters, configuration parameters, and target damping coefficient of the magnetorheological damper under the shimmy instability mode of the target front wheel. The driving parameters include front wheel steering angle, front wheel angular velocity, vehicle speed, and front wheel slip angle. The configuration parameters include tire-related parameters, moment of inertia, and reducer transmission ratio. The product of the target damping coefficient and the front wheel angular velocity is equal to the product of the initial damping coefficient of the magnetorheological damper and the magnetorheological damper current.

[0009] Based on the steering system dynamics equations, the characteristic equations and all characteristic value expressions are obtained using the front wheel steering angle, the front wheel angular velocity, and the front wheel sideslip angle as variables;

[0010] The real-time values ​​of the driving parameters of the target front wheel, the values ​​of the configuration parameters, the real-time value of the magnetorheological damper current, and the value of the initial damping coefficient are obtained.

[0011] Input the real-time values ​​of the driving parameters and the values ​​of the configuration parameters into all the feature value expressions to obtain the real parts of all feature values;

[0012] Based on the initial damping coefficient value, the real-time value of the magnetorheological damper current, and the real part value, it is determined whether there is at least one characteristic value whose real part value is greater than zero. Then, the real-time value of the magnetorheological damper current is adjusted until the real part value of all characteristic values ​​is not greater than zero, so as to obtain the target damping coefficient value.

[0013] In the control method of the steer-by-wire system provided in the first aspect of the present invention, the step of constructing the steering system dynamic equation based on the driving parameters, configuration parameters and target damping coefficient of the magnetorheological damper under the shimmy instability mode of the target front wheel includes: firstly constructing a first transient dynamic equation between the front wheel steering angle and the magnetorheological damper based on the driving parameters, configuration parameters and target damping coefficient of the magnetorheological damper under the shimmy instability mode of the target front wheel; secondly constructing a second transient dynamic equation between the front wheel steering angle and the front wheel slip angle; and finally constructing a constraint equation between the front wheel slip angle and the front wheel slip force. The steering system dynamic equation is obtained based on the first transient dynamic equation, the second transient dynamic equation and the constraint equation, using the front wheel steering angle, the front wheel angular velocity and the front wheel slip angle as variables.

[0014] In the control method of the steer-by-wire system provided in the first aspect of the present invention, the step of obtaining the characteristic equation and all eigenvalue expressions based on the steering system dynamic equation, using the front wheel steering angle, the front wheel angular velocity, and the front wheel sideslip angle as variables, includes: differentiating the steering system dynamic equation with the front wheel steering angle, the front wheel angular velocity, and the front wheel sideslip angle as variables to obtain the Jacobian matrix; and obtaining the characteristic equation and all eigenvalue expressions based on the Jacobian matrix.

[0015] In the control method of the steer-by-wire system provided in the first aspect of the present invention, adjusting the real-time value of the magnetorheological damper current includes: successively increasing the real-time value of the magnetorheological damper current according to a set current step size.

[0016] The control method for the steer-by-wire system provided in the first aspect of the present invention further includes: calculating the shimmy instability mode frequency of the target front wheel after the real part of all eigenvalues ​​is not greater than zero.

[0017] According to a second aspect of the invention, a control system for a steer-by-wire system is also provided, the steer-by-wire system being arranged on a target front wheel of a vehicle, the steer-by-wire system including a reducer and a magnetorheological damper, the magnetorheological damper being arranged on the output shaft of the reducer, the control system including:

[0018] The dynamic equation construction module is used to construct the steering system dynamic equation based on the driving parameters, configuration parameters, and target damping coefficient of the magnetorheological damper under the shimmy instability mode of the target front wheel. The driving parameters include front wheel steering angle, front wheel angular velocity, vehicle speed, and front wheel slip angle. The configuration parameters include tire-related parameters, moment of inertia, and reducer transmission ratio. The product of the target damping coefficient and the front wheel angular velocity is equal to the product of the initial damping coefficient of the magnetorheological damper and the magnetorheological damper current.

[0019] The characteristic equation construction module is used to obtain the characteristic equation and all characteristic value expressions based on the steering system dynamic equation, using the front wheel steering angle, the front wheel steering angular velocity and the front wheel slip angle as variables;

[0020] The data acquisition module is used to acquire the real-time values ​​of the driving parameters of the target front wheel, the values ​​of the configuration parameters, the real-time value of the magnetorheological damper current, and the value of the initial damping coefficient.

[0021] The calculation module is used to input the real-time values ​​of the driving parameters and the values ​​of the configuration parameters into the expression for all feature values ​​to obtain the real part values ​​of all feature values;

[0022] The control module is used to determine whether there is at least one feature value with a real part greater than zero based on the value of the initial damping coefficient, the real value of the magnetorheological damper current, and the real part value. If so, the real value of the magnetorheological damper current is adjusted until the real part value of all feature values ​​is not greater than zero, so as to obtain the value of the target damping coefficient.

[0023] In the control system of the steer-by-wire system provided in the second aspect of the present invention, the dynamic equation construction module is used to: firstly construct a first transient dynamic equation between the front wheel steering angle and the magnetorheological damper based on the driving parameters, configuration parameters and target damping coefficient of the magnetorheological damper under the shimmy instability mode of the target front wheel; secondly construct a second transient dynamic equation between the front wheel steering angle and the front wheel slip angle; and finally construct a constraint equation between the front wheel slip angle and the front wheel slip force. The steering system dynamic equation is obtained based on the first transient dynamic equation, the second transient dynamic equation and the constraint equation, using the front wheel steering angle, the front wheel angular velocity and the front wheel slip angle as variables.

[0024] In the control system of the steer-by-wire system provided in the second aspect of the present invention, the characteristic equation construction module is specifically used to: differentiate the dynamic equation of the steering system with the front wheel steering angle, the front wheel steering angular velocity and the front wheel slip angle as variables to obtain the Jacobian matrix; and obtain the characteristic equation and all eigenvalue expressions based on the Jacobian matrix.

[0025] In the control system of the steer-by-wire system provided in the second aspect of the present invention, the control module is specifically used to: successively increase the real-time value of the magnetorheological damper current according to a set current step size.

[0026] According to a third aspect of the present invention, a control device for a steer-by-wire system is also provided, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the control method for the steer-by-wire system proposed in the first aspect of the present invention.

[0027] In one or more aspects of the present invention, a steer-by-wire system is arranged on a target front wheel of a vehicle. The steer-by-wire system includes a reducer and a magnetorheological damper, the magnetorheological damper being arranged on the output shaft of the reducer. The control method includes: constructing a steering system dynamic equation based on the target front wheel's driving parameters, configuration parameters, and the target damping coefficient of the magnetorheological damper under the shimmy instability mode. The driving parameters include front wheel steering angle, front wheel angular velocity, vehicle speed, and front wheel slip angle. The configuration parameters include tire-related parameters, moment of inertia, and reducer gear ratio. The product of the target damping coefficient and the front wheel angular velocity is equal to the product of the initial damping coefficient of the magnetorheological damper and the magnetorheological damper current. Based on the steering system dynamics equations, the characteristic equation and all eigenvalue expressions are obtained using the front wheel steering angle, front wheel angular velocity, and front wheel sideslip angle as variables. Real-time values ​​of the target front wheel's driving parameters, configuration parameters, magnetorheological damper current, and initial damping coefficient are acquired. The real-time values ​​of the driving parameters and configuration parameters are input into all eigenvalue expressions to obtain the real parts of all eigenvalues. Based on the initial damping coefficient, the real-time value of the magnetorheological damper current, and the real parts, it is determined whether at least one eigenvalue has a real part greater than zero. If so, the real-time value of the magnetorheological damper current is adjusted until the real parts of all eigenvalues ​​are not greater than zero, thus obtaining the target damping coefficient. In this case, by adding a magnetorheological damper to the output shaft of the reducer, the steering system dynamics equations are constructed, leading to the characteristic equations. By adjusting the real-time value of the magnetorheological damper current to ensure that the real parts of all eigenvalues ​​are not greater than zero, the target damping coefficient is obtained. At this point, the system is no longer underdamped, resolving the front wheel shimmy problem.

[0028] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0029] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0030] Figure 1 This diagram illustrates an application scenario of the steer-by-wire system provided in an embodiment of the present invention.

[0031] Figure 2 This shows a structural side view of the steer-by-wire system provided in an embodiment of the present invention;

[0032] Figure 3 This diagram illustrates a flow chart of a control method for a steer-by-wire system provided in an embodiment of the present invention.

[0033] Figure 4 A flowchart illustrating the method for constructing the dynamic equations of a steering system provided in an embodiment of the present invention is shown.

[0034] Figure 5 A block diagram of the control system of the steer-by-wire system provided in an embodiment of the present invention is shown;

[0035] Figure 6 This is a block diagram of the control device for the steer-by-wire system used to implement the control method of the steer-by-wire system in the embodiments of the present invention. Detailed Implementation

[0036] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of the present invention as detailed in the appended claims.

[0037] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0038] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. It should also be understood that the term "and / or" as used in this invention refers to and includes any or all possible combinations of one or more associated listed items.

[0039] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0040] This invention provides a control method and control system for a steer-by-wire system, with the main objective of solving the problem of front wheel shimmy.

[0041] In this invention, a steer-by-wire system is positioned on the target front wheel of the vehicle. The steer-by-wire system includes a reducer and a magnetorheological damper, with the magnetorheological damper positioned on the output shaft of the reducer. The magnetorheological damper and the output shaft are rigidly connected without any gaps.

[0042] In this invention, the target front wheel is selected from one of the front wheels.

[0043] Figure 1 The diagram illustrates an application scenario of the steer-by-wire system provided in an embodiment of the present invention. Figure 2 A structural side view of the steer-by-wire system provided in an embodiment of the present invention is shown. Figure 1 The wheel shown is an integrated steering wheel, which includes a single wheel and the steer-by-wire system of the present invention.

[0044] like Figure 2 As shown, the steer-by-wire system of the present invention includes a motor 1, a motor mounting plate 2, a first motor coupling 3, a second motor coupling 4, an angle transmission mechanism 5, a steering angle sensor 6, a steering angle sensor mounting plate 7, a magnetorheological damper 8, a damper flange 9, and a reducer 10. The motor 1 can be a PMSM (Permanent Magnet Synchronous Motor), and is fixed to the motor mounting plate 2. One end of the motor mounting plate 2 is fixed to the motor 1, and the other end is fixed to the reducer 10. One end of the first motor coupling 3 is fixed to the motor 1 by a pin, and the other end engages with the second motor coupling 4. One end of the second motor coupling 4 is fixed to the reducer 10 by a pin, and the other end engages with the first motor coupling 3. The inner ring of the angle transmission mechanism 5 is fixed to the drive shaft (i.e., the output shaft), and the outer ring engages with the steering angle sensor 6. The steering angle sensor 6 is fixed to the steering angle sensor mounting plate 7. Angle sensor mounting plate 7 is used to fix angle sensor 6. One end of angle sensor mounting plate 7 is connected to magnetorheological damper 8, and the other end is connected to angle sensor 6. The inner ring of magnetorheological damper 8 is fixed to the drive shaft. One end of magnetorheological damper 8 is fixed to angle sensor mounting plate 7, and the other end is fixed to damper flange 9. One end of damper flange 9 is fixed to magnetorheological damper 8, and the other end is fixed to reducer 10. Reducer 10 passes through the drive shaft. One end of reducer 10 is fixed to damper flange 9, and the other end is fixed to motor mounting plate 2.

[0045] Specifically, traditional automotive steering mechanisms have a certain amount of steering clearance, primarily generated by the reducer in steer-by-wire systems. This problem is unavoidable for both worm gear reducers and rack and pinion reducers. Furthermore, over time, the clearance gradually increases, causing wheel wobble. This wobble cannot be transmitted to the steering actuator motor and therefore cannot be controlled by it. Within this clearance range, the wheel experiences less friction, resulting in less damping and more severe shimmy. This invention adds a magnetorheological damper and positions it on the reducer's output shaft. The steer-by-wire system control method of this invention controls the magnetorheological damper, improving the underdamped wheel condition and thus solving the front wheel shimmy problem.

[0046] The control method of the steer-by-wire system of the present invention is described in detail below.

[0047] In the first embodiment, Figure 3 This diagram illustrates a flow chart of a control method for a steer-by-wire system according to an embodiment of the present invention. Figure 3 As shown, the control method of the steer-by-wire system includes:

[0048] Step S11: Construct the dynamic equation of the steering system based on the driving parameters, configuration parameters of the target front wheel and the target damping coefficient of the magnetorheological damper under the shimmy instability mode.

[0049] In step S11, the driving parameters include, but are not limited to, front wheel steering angle, front wheel steering angular velocity, front wheel steering angular acceleration, wheel angular damping about its kingpin, suspension damping about its kingpin, vehicle speed, front wheel slip angle, front wheel slip angular velocity, and the equivalent frictional resistance torque of the entire integral wheel.

[0050] In step S11, the configuration parameters include, but are not limited to, tire-related parameters, moment of inertia, motor output torque, and reducer gear ratio. The moment of inertia includes the moment of inertia of the target front wheel assembly about its kingpin. Tire-related parameters include tire mechanical trail, tire slack length, tire contact patch half-length, and tire formula parameters.

[0051] In step S11, the product of the target damping coefficient of the magnetorheological damper in the shimmy instability mode and the front wheel angular velocity is equal to the product of the initial damping coefficient of the magnetorheological damper and the magnetorheological damper current. Here, the shimmy instability mode refers to the shimmy-free state.

[0052] Figure 4 This is a schematic flowchart illustrating the method for constructing the dynamic equations of a steering system provided in an embodiment of the present invention.

[0053] like Figure 4As shown, the method for constructing the steering system dynamic equation in step S11 includes: based on the target front wheel's driving parameters, configuration parameters, and the target damping coefficient of the magnetorheological damper under the shimmy instability mode, firstly, a first transient dynamic equation between the front wheel steering angle and the magnetorheological damper is constructed (step S111); then, a second transient dynamic equation between the front wheel steering angle and the front wheel slip angle is constructed (step S112); finally, a constraint equation between the front wheel slip angle and the front wheel slip force is constructed (step S113); using the front wheel steering angle, front wheel angular velocity, and front wheel slip angle as variables, the steering system dynamic equation is obtained based on the first transient dynamic equation, the second transient dynamic equation, and the constraint equation (step S114).

[0054] In step S111, for the target front wheel of the present invention, a first transient dynamic equation is established to represent the transient dynamic relationship between the front wheel's angular velocity and the magnetorheological damper. The first transient dynamic equation satisfies equation (1):

[0055]

[0056] In the formula, It is the angular velocity of the front wheels; J1 is the front wheel angular acceleration; J2 is the moment of inertia of the target front wheel assembly about its kingpin; c1 is the angular damping of the wheel about its kingpin; c2 is the damping of the suspension about its kingpin; c b It is the target damping coefficient of the magnetorheological damper under the oscillation instability mode; n is the tire mechanical trail; F y1 It is the lateral force of the target front wheel; M f M is the equivalent frictional resistance torque of the entire device (i.e., the entire integrated wheel). d Let i be the motor output torque, and i0 be the reducer gear ratio. Let... M c I is the drag torque of the magnetorheological damper. m It is the current of the magnetorheological damper, c b0 is the initial damping coefficient of the magnetorheological damper.

[0057] In step S111, it is assumed that the tire mechanical trail is 0, the front wheel angular acceleration is 0, the current of the magnetorheological damper is I0, and the dynamic friction torque is M. f0 Then the equivalent frictional resistance torque M of the entire device f The drag torque M of the magnetorheological damper c Satisfying equation (2):

[0058]

[0059] Equation (2) characterizes the static and dynamic characteristics of the steer-by-wire system. In the static state, i.e., when the wheels are not rotating, M satisfies...c +M f =M c +M f The dynamic characteristics are such that when the wheel rotates, it satisfies Wherein, + indicates forward rotation and - indicates reverse rotation. The control method of this invention mainly considers its dynamic characteristics and the assumptions made above. There is no conflict.

[0060] In step S112, for the target front wheel of the present invention, a second transient dynamic equation is established to represent the transient dynamic constraint relationship between its vehicle speed, front wheel steering angle, and front wheel sideslip angle. The second transient dynamic equation satisfies equation (3):

[0061]

[0062] In the formula, θ1 is the front wheel steering angle, and α1 is the front wheel slip angle. Let v be the front wheel slip angular velocity, v be the vehicle speed, and σ0 be the tire slack length; a m0 It is half the length of the tire contact patch.

[0063] In step S113, for the target front wheel of the present invention, a constraint equation is established between the front wheel slip angle and the front wheel lateral force of the target front wheel. The front wheel lateral force is a nonlinear lateral force. This constraint equation satisfies equation (4):

[0064]

[0065] In the formula, F y1 It is the target front wheel lateral force, α1 is the front wheel lateral slip angle, and k t and k s These are tire formula parameters.

[0066] In step S114, the front wheel steering angle, front wheel steering angular velocity, and front wheel slip angle are introduced as variables. Transforming the first transient dynamic equation, the second transient dynamic equation, and the constraint equations, we obtain the steering system dynamic equation, which satisfies equation (5):

[0067]

[0068] In the formula, Γ is an abbreviation for the expression. R 3 It represents the three-dimensional real number field.

[0069] Combining equations (1), (3), and (4), the expression Γ can be expressed as equation (6):

[0070]

[0071]

[0072]

[0073] Equation (6) can be expressed in matrix form as equation (7), which satisfies:

[0074]

[0075] Step S12: Based on the steering system dynamics equations, the characteristic equations and expressions for all characteristic values ​​are obtained using the front wheel steering angle, front wheel steering angular velocity, and front wheel slip angle as variables.

[0076] In step S12, based on the steering system dynamics equation, the characteristic equation and all eigenvalue expressions are obtained with the front wheel angle, front wheel angular velocity and front wheel slip angle as variables, including: taking the derivative of the steering system dynamics equation with the front wheel angle, front wheel angular velocity and front wheel slip angle as variables to obtain the Jacobian matrix; and obtaining the characteristic equation and all eigenvalue expressions based on the Jacobian matrix.

[0077] Specifically, the derivative of the steering system dynamics equations is obtained, that is, by using... The Jacobian matrix of equation (6) can be solved, and the Jacobian matrix satisfies equation (8):

[0078]

[0079] In the formula, x0 can be the front wheel steering angle, front wheel steering angular velocity, and front wheel slip angle at the current vehicle speed and current state.

[0080] Then, substituting the Jacobian matrix M(v) into det|M(v)-λI|=0, M(v)-λI satisfies equation (9). Combining this with the general form of the third-order characteristic equation of the system shown in equation (10), we obtain the characteristic equation of this invention. The characteristic equation of this invention satisfies equation (11):

[0081]

[0082] μ3λ 3 +μ2λ 2 +μ1λ+μ0=0 (10)

[0083] Where I is the identity matrix, λ is the eigenvalue, and μ3, μ2, μ1, and μ0 are real or complex numbers, with μ3 ≠ 0.

[0084] Equation (10) is the general expression of this equation. In this invention, the characteristic equation of equation (9) is as follows:

[0085]

[0086] Based on the characteristic equation shown in equation (11), this invention has three eigenvalues, namely λ1, λ2, and λ3. Let all their eigenvalue expressions be λ1 = a1 + b1i, λ2 = a2 + b2i, and λ3 = a3 + b3i. These three eigenvalue expressions can be obtained from the above-mentioned c1, c2, c3 involved in the dynamic equation of the steering system. b The parameters are expressed, where the real parts a1, a2, a3 in the three eigenvalue expressions can all be expressed using c1, c2, c3. b The parameters are listed.

[0087] Step S13: Obtain the real-time values ​​of the target front wheel's driving parameters, configuration parameters, magnetorheological damper current, and initial damping coefficient.

[0088] In step S13, the real-time values ​​of the driving parameters of the target front wheel are obtained, namely, the real-time values ​​of the front wheel steering angle, front wheel angular velocity, front wheel angular acceleration, wheel angular damping around its kingpin, suspension damping around its kingpin, vehicle speed, front wheel slip angle, front wheel slip angular velocity, and the equivalent frictional resistance torque of the entire integrated wheel.

[0089] In step S13, the acquired configuration parameter values ​​include tire-related parameters, moment of inertia, motor output torque, and reducer transmission ratio. The moment of inertia value includes the moment of inertia of the target front wheel assembly about its kingpin. The tire-related parameter values ​​include tire mechanical trail, tire slack length, tire contact patch half-length, and tire formula parameters.

[0090] In step S13, the real-time value of the magnetorheological damper current is obtained as the current I of the magnetorheological damper. m The real-time value. The obtained initial damping coefficient value is the initial damping coefficient c of the magnetorheological damper. b0 The value of .

[0091] Step S14: Input the real-time values ​​of the driving parameters and the values ​​of the configuration parameters into all feature value expressions to obtain the real part values ​​of all feature values.

[0092] In step S14, the desired parameter values ​​are selected from the parameter values ​​obtained in step S13, substituted into all eigenvalue expressions, and the real parts of all eigenvalues ​​are obtained. Wherein, due to the target damping coefficient c... b Since the value is unknown, the real part of some or all of the eigenvalues ​​is the target damping coefficient c. b The expression is for variables. According to the stability criterion for continuous systems, the system is stable only if the real parts of all eigenvalues ​​are less than 0. Therefore, the target damping coefficient c of the magnetorheological damper in the oscillating instability mode is... bUnder the condition that a1<0, a2<0, a3<0, the target front wheel will not wobble.

[0093] Step S15: Based on the initial damping coefficient value, the real-time value of the magnetorheological damper current and the real part value, determine whether there is at least one characteristic value whose real part value is greater than zero. Then adjust the real-time value of the magnetorheological damper current until the real part value of all characteristic values ​​is not greater than zero, so as to obtain the target damping coefficient value.

[0094] In step S15, considering that when the target front wheel exhibits shimmy, it indicates insufficient damping force, the system is underdamped, and the system is unstable. To resolve the front wheel shimmy problem, the damping coefficient of the magnetorheological damper needs to be adjusted to the target damping coefficient. It is also considered that the damping coefficient of the magnetorheological damper cannot be directly adjusted, and the drag torque of the magnetorheological damper is linearly related to the magnitude of the current in the magnetorheological damper. Among them, M c Let I be the resistance torque of the magnetorheological damper, and c be the current in the magnetorheological damper. b0 The initial damping coefficient of the magnetorheological damper is given by the current I of the magnetorheological damper, which can be directly adjusted. m This allows for the adjustment of the damping coefficient of the magnetorheological damper. When the current I of the magnetorheological damper is adjusted... m Then, when the real parts of all eigenvalues ​​are less than or equal to zero, the damping coefficient of the magnetorheological damper at this point is the target damping coefficient c. b The value was adjusted, the system stabilized, and the front wheel shimmy problem was resolved.

[0095] In step S15, adjusting the real-time value of the magnetorheological damper current includes: gradually increasing the real-time value of the magnetorheological damper current according to a set current step size. That is, I k =I1 + k × ΔI, where I1 is the real-time value of the magnetorheological damper current when oscillation occurs, ΔI is the current step size, k is the number of adjustments, and I k This represents the real-time value of the magnetorheological damper current after each adjustment.

[0096] In an embodiment of the present invention, the control method for the steer-by-wire system further includes: calculating the shimmy instability mode frequency of the target front wheel after the real parts of all eigenvalues ​​are not greater than zero. The target front wheel shimmy instability mode frequency f s satisfy Where b is the resonant angular frequency.

[0097] In the control method of the steer-by-wire system in this embodiment of the invention, the steer-by-wire system is arranged on the target front wheel of the vehicle. The steer-by-wire system includes a reducer and a magnetorheological damper. The magnetorheological damper is arranged on the output shaft of the reducer. The control method includes: constructing a dynamic equation of the steering system based on the driving parameters, configuration parameters, and target damping coefficient of the magnetorheological damper under the shimmy instability mode of the target front wheel. The driving parameters include the front wheel steering angle, front wheel angular velocity, vehicle speed, and front wheel slip angle. The configuration parameters include tire-related parameters, moment of inertia, and reducer transmission ratio. The product of the target damping coefficient and the front wheel angular velocity is equal to the initial damping coefficient of the magnetorheological damper and the magnetorheological damper current. The system is constructed by adding a magnetorheological damper to the output shaft of the reducer. Based on the steering system dynamics equations, the characteristic equations and all eigenvalue expressions are obtained using the front wheel steering angle, front wheel angular velocity, and front wheel slip angle as variables. Real-time values ​​of the target front wheel's driving parameters, configuration parameters, magnetorheological damper current, and initial damping coefficient are acquired. The real-time values ​​of the driving parameters and configuration parameters are input into all eigenvalue expressions to obtain the real parts of all eigenvalues. Based on the initial damping coefficient, the real-time value of the magnetorheological damper current, and the real parts, it is determined whether at least one eigenvalue has a real part greater than zero. If so, the real-time value of the magnetorheological damper current is adjusted until the real parts of all eigenvalues ​​are not greater than zero, thus obtaining the target damping coefficient. In this case, by adding a magnetorheological damper to the output shaft of the reducer, the steering system dynamics equations are constructed, and the characteristic equations are obtained. By adjusting the real-time value of the magnetorheological damper current to ensure that the real parts of all eigenvalues ​​are not greater than zero, the target damping coefficient is obtained. At this point, the system is no longer underdamped, and the front wheel shimmy problem is solved.

[0098] The control method of the steer-by-wire system in this invention is applicable to ordinary vehicles and some special vehicles, and features adjustable damping. Specifically, this invention uses a magnetorheological damper combined with a control method to adjust the damping of the entire system, solving the tire shimmy problem that occurs in the steering wheel under medium and high speed conditions, and increasing the vehicle's driving stability and safety.

[0099] The following are system embodiments of the present invention, which can be used to execute the method embodiments of the present invention. For details not disclosed in the system embodiments of the present invention, please refer to the method embodiments of the present invention.

[0100] Please see Figure 5 , Figure 5This diagram illustrates a block diagram of the control system for a steer-by-wire system provided in an embodiment of the present invention. The control system of this steer-by-wire system can be implemented as all or part of the system through software, hardware, or a combination of both. The steer-by-wire system is mounted on the target front wheel of the vehicle and includes a reducer and a magnetorheological damper, with the magnetorheological damper mounted on the output shaft of the reducer. The control system of this steer-by-wire system includes a dynamic equation construction module, a characteristic equation construction module, a data acquisition module, a calculation module, and a control module, wherein:

[0101] The dynamic equation construction module is used to construct the dynamic equation of the steering system based on the driving parameters, configuration parameters, and target damping coefficient of the magnetorheological damper under the shimmy instability mode of the target front wheel. The driving parameters include front wheel steering angle, front wheel angular velocity, vehicle speed, and front wheel slip angle. The configuration parameters include tire-related parameters, moment of inertia, and reducer transmission ratio. The product of the target damping coefficient and the front wheel angular velocity is equal to the product of the initial damping coefficient of the magnetorheological damper and the current of the magnetorheological damper.

[0102] The characteristic equation construction module is used to obtain the characteristic equation and all characteristic value expressions based on the steering system dynamics equation, with the front wheel steering angle, front wheel steering angular velocity and front wheel sideslip angle as variables.

[0103] The data acquisition module is used to acquire real-time values ​​of the target front wheel's driving parameters, configuration parameters, magnetorheological damper current, and initial damping coefficient.

[0104] The calculation module is used to input the real-time values ​​of driving parameters and configuration parameters into all feature value expressions to obtain the real part values ​​of all feature values;

[0105] The control module is used to determine whether there is at least one characteristic value with a real part greater than zero, based on the initial damping coefficient value, the real-time value of the magnetorheological damper current and its real part value. If so, it adjusts the real-time value of the magnetorheological damper current until the real part value of all characteristic values ​​is not greater than zero, so as to obtain the target damping coefficient value.

[0106] Optionally, the dynamic equation construction module is specifically used to: based on the target front wheel's driving parameters, configuration parameters, and the target damping coefficient of the magnetorheological damper under the shimmy instability mode, firstly construct the first transient dynamic equation between the front wheel steering angle and the magnetorheological damper, then construct the second transient dynamic equation between the front wheel steering angle and the front wheel slip angle, and finally construct the constraint equation between the front wheel slip angle and the front wheel slip force. Using the front wheel steering angle, front wheel angular velocity, and front wheel slip angle as variables, the steering system dynamic equation is obtained based on the first transient dynamic equation, the second transient dynamic equation, and the constraint equation.

[0107] Optionally, the characteristic equation construction module is specifically used to: differentiate the steering system dynamics equations with front wheel steering angle, front wheel steering angular velocity, and front wheel slip angle as variables to obtain the Jacobian matrix; and obtain the characteristic equations and all eigenvalue expressions based on the Jacobian matrix.

[0108] Optionally, the control module is specifically used to: gradually increase the real-time value of the magnetorheological damper current according to the set current step size.

[0109] Optionally, the control module is also used to calculate the shimmy instability mode frequency of the target front wheel after the real part of all eigenvalues ​​is not greater than zero.

[0110] It should be noted that the control system of the steer-by-wire system provided in the above embodiments is only illustrated by the division of the above functional modules when executing the control method of the steer-by-wire system. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the control device of the steer-by-wire system can be divided into different functional modules to complete all or part of the functions described above. In addition, the control system of the steer-by-wire system provided in the above embodiments and the control method embodiments of the steer-by-wire system belong to the same concept, and its implementation process is detailed in the method embodiments, which will not be repeated here.

[0111] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0112] In the control system of the steer-by-wire system of this invention, the dynamic equation construction module is used to construct the steering system dynamic equation based on the target front wheel's driving parameters, configuration parameters, and the target damping coefficient of the magnetorheological damper under the shimmy instability mode. The driving parameters include the front wheel steering angle, front wheel angular velocity, vehicle speed, and front wheel slip angle. The configuration parameters include tire-related parameters, moment of inertia, and reducer gear ratio. The product of the target damping coefficient and the front wheel angular velocity is equal to the product of the initial damping coefficient of the magnetorheological damper and the magnetorheological damper current. The characteristic equation construction module is used to construct the steering system dynamic equation based on the steering system dynamic equation, considering the front wheel steering angle, front wheel angular velocity, and front wheel slip angle. The system uses the deflection angle as a variable to obtain the characteristic equation and expressions for all eigenvalues. The data acquisition module acquires real-time values ​​of the target front wheel's driving parameters, configuration parameters, magnetorheological damper current, and initial damping coefficient. The calculation module inputs the real-time driving parameters and configuration parameters into all eigenvalue expressions to obtain the real parts of all eigenvalues. The control module, based on the initial damping coefficient, the real-time magnetorheological damper current, and its real parts, determines if at least one eigenvalue has a real part greater than zero. If so, it adjusts the real-time magnetorheological damper current until the real parts of all eigenvalues ​​are not greater than zero, thus obtaining the target damping coefficient. In this scenario, by adding a magnetorheological damper to the reducer's output shaft, the steering system's dynamic equations are constructed, leading to the characteristic equation. By adjusting the real-time magnetorheological damper current to ensure the real parts of all eigenvalues ​​are not greater than zero, the target damping coefficient is obtained. At this point, the system is no longer underdamped, resolving the front wheel shimmy problem.

[0113] According to embodiments of the present invention, the present invention also provides a control device for a steer-by-wire system, a readable storage medium, and a computer program product.

[0114] Figure 6 This is a block diagram of a control device for a steer-by-wire system used to implement the control method of the steer-by-wire system according to embodiments of the present invention. The control device for the steer-by-wire system is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The control device for the steer-by-wire system can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable electronic devices, and other similar computing devices. The components, connections and relationships between components, and functions of components shown in this invention are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0115] like Figure 6As shown, the control device 20 of the steer-by-wire system includes a computing unit 21, which can perform various appropriate actions and processes based on a computer program stored in a read-only memory (ROM) 22 or a computer program loaded from a storage unit 28 into a random access memory (RAM) 23. The RAM 23 may also store various programs and data required for the operation of the control device 20 of the steer-by-wire system. The computing unit 21, ROM 22, and RAM 23 are interconnected via a bus 24. An input / output (I / O) interface 25 is also connected to the bus 24.

[0116] Multiple components in the control device 20 of the steer-by-wire system are connected to the I / O interface 25, including: an input unit 26, such as a keyboard, mouse, etc.; an output unit 27, such as various types of displays, speakers, etc.; a storage unit 28, such as a disk, optical disk, etc., which is communicatively connected to the computing unit 21; and a communication unit 29, such as a network card, modem, wireless transceiver, etc. The communication unit 29 allows the control device 20 of the steer-by-wire system to exchange information / data with other control devices of the steer-by-wire system through computer networks such as the Internet and / or various telecommunications networks.

[0117] The computing unit 21 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 21 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 21 performs the various methods and processes described above, such as performing a control method for a steer-by-wire system. For example, in some embodiments, the control method for a steer-by-wire system may be implemented as a computer software program tangibly contained in a machine-readable medium, such as storage unit 28. In some embodiments, part or all of the computer program may be loaded and / or installed on the control device 20 of the steer-by-wire system via ROM 22 and / or communication unit 29. When the computer program is loaded into RAM 23 and executed by the computing unit 21, one or more steps of the control method for a steer-by-wire system described above may be performed. Alternatively, in other embodiments, the computing unit 21 may be configured to perform the control method for a steer-by-wire system by any other suitable means (e.g., by means of firmware).

[0118] Various embodiments of the systems and techniques described above in this invention can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic electronic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0119] The program code used to implement the methods of the present invention can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code can be executed entirely on the machine, partially on the machine, as a standalone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0120] In this invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with the control device of an instruction execution system, apparatus, or steering-by-wire system. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or electronic devices, or any suitable combination thereof. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage electronics, magnetic storage electronics, or any suitable combination thereof.

[0121] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0122] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or middleware components (e.g., application servers), or frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), the Internet, and blockchain networks.

[0123] Computer systems can include clients and servers. Clients and servers are generally geographically separated and typically interact via communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. A server can be a cloud server, also known as a cloud computing server or cloud host, a hosting product within the cloud computing service ecosystem, addressing the shortcomings of traditional physical hosts and VPS (Virtual Private Server, or simply "VPS") services, such as high management difficulty and weak business scalability. Servers can also be servers for distributed systems or servers incorporating blockchain technology.

[0124] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this invention does not impose any limitations on them.

[0125] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A control method of a steer-by-wire system, characterized by, A steer-by-wire system is arranged on a target front wheel of a vehicle, the steer-by-wire system comprising a reducer and a magneto-rheological damper arranged on an output shaft of the reducer, and the control method comprises: constructing a steering system dynamics equation based on driving parameters of the target front wheel, configuration parameters and a target damping coefficient of the magneto-rheological damper in a shimmy instability mode, the driving parameters comprising a front wheel steering angle, a front wheel steering angle velocity, a vehicle speed, a front wheel side slip angle, the configuration parameters comprising tire-related parameters, a moment of inertia and a reducer transmission ratio, wherein a product of the target damping coefficient and the front wheel steering angle velocity is equal to a product of an initial damping coefficient of the magneto-rheological damper and a magneto-rheological damper current; obtaining a characteristic equation and all eigenvalue expressions based on the steering system dynamics equation with the front wheel steering angle, the front wheel steering angle velocity and the front wheel side slip angle as variables; obtaining real-time values of the driving parameters of the target front wheel, values of the configuration parameters, a magneto-rheological damper current real-time value and a value of the initial damping coefficient; inputting the real-time values of the driving parameters and the values of the configuration parameters into the all eigenvalue expressions to obtain real part values of all eigenvalues; based on the value of the initial damping coefficient, the magneto-rheological damper current real-time value and the real part values, judging whether there is at least one eigenvalue whose real part value is greater than zero, then adjusting the magneto-rheological damper current real-time value until real part values of all eigenvalues are not greater than zero to obtain a value of the target damping coefficient.

2. The control method of the steer-by-wire system according to claim 1, characterized by, The constructing of the steering system dynamics equation based on the driving parameters of the target front wheel, the configuration parameters and the target damping coefficient of the magneto-rheological damper in the shimmy instability mode comprises: based on the driving parameters of the target front wheel, the configuration parameters and the target damping coefficient of the magneto-rheological damper in the shimmy instability mode, first constructing a first transient dynamics equation between the front wheel steering angle and the magneto-rheological damper, then constructing a second transient dynamics equation between the front wheel steering angle and the front wheel side slip angle, and finally constructing a constraint equation between the front wheel side slip angle and a front wheel side slip force, to obtain the steering system dynamics equation based on the first transient dynamics equation, the second transient dynamics equation and the constraint equation with the front wheel steering angle, the front wheel steering angle velocity and the front wheel side slip angle as variables.

3. The control method of the steer-by-wire system according to claim 2, characterized by, The obtaining of the characteristic equation and all eigenvalue expressions based on the steering system dynamics equation with the front wheel steering angle, the front wheel steering angle velocity and the front wheel side slip angle as variables comprises: deriving the steering system dynamics equation to obtain a Jacobian matrix with the front wheel steering angle, the front wheel steering angle velocity and the front wheel side slip angle as variables; obtaining the characteristic equation and all eigenvalue expressions based on the Jacobian matrix.

4. The control method of the steer-by-wire system according to claim 3, characterized by, The adjusting of the magneto-rheological damper current real-time value comprises: increasing the magneto-rheological damper current real-time value by a set current step length.

5. The control method of the steer-by-wire system according to claim 4, characterized by, Further comprising: after the real part values of all eigenvalues are not greater than zero, calculating to obtain a shimmy instability mode frequency of the target front wheel.

6. A control system for a steer-by-wire system, characterized in that A steer-by-wire system is arranged on a target front wheel of a vehicle, the steer-by-wire system comprising a reducer and a magneto-rheological damper arranged on an output shaft of the reducer, the control system comprising: a dynamic equation construction module configured to construct a steering system dynamic equation based on driving parameters of the target front wheel, configuration parameters, and a target damping coefficient of the magneto-rheological damper in a shimmy instability mode, the driving parameters comprising a front wheel angle, a front wheel angle velocity, a vehicle speed, and a front wheel side slip angle, the configuration parameters comprising tire-related parameters, a moment of inertia, and a reducer transmission ratio, wherein a product of the target damping coefficient and the front wheel angle velocity is equal to a product of an initial damping coefficient of the magneto-rheological damper and a magneto-rheological damper current; a characteristic equation construction module configured to obtain a characteristic equation and all characteristic value expressions based on the steering system dynamic equation, with the front wheel angle, the front wheel angle velocity, and the front wheel side slip angle as variables; a data acquisition module configured to acquire real-time values of the driving parameters of the target front wheel, values of the configuration parameters, a magneto-rheological damper current real-time value, and a value of the initial damping coefficient; a calculation module configured to input the real-time values of the driving parameters and the values of the configuration parameters into the all characteristic value expressions to obtain real part values of all characteristic values; a regulation module configured to determine, based on the value of the initial damping coefficient, the magneto-rheological damper current real-time value, and the real part values, whether there is at least one characteristic value whose real part value is greater than zero, and then adjust the magneto-rheological damper current real-time value until the real part values of all characteristic values are not greater than zero to obtain a value of the target damping coefficient.

7. A control system for a steer-by-wire steering system as claimed in claim 6, characterised in that, The dynamic equation construction module is configured to: based on the driving parameters of the target front wheel, the configuration parameters, and the target damping coefficient of the magneto-rheological damper in the shimmy instability mode, first construct a first transient dynamic equation between the front wheel angle and the magneto-rheological damper, then construct a second transient dynamic equation between the front wheel angle and the front wheel side slip angle, and finally construct a constraint equation between the front wheel side slip angle and a front wheel side slip force, to obtain the steering system dynamic equation based on the first transient dynamic equation, the second transient dynamic equation, and the constraint equation, with the front wheel angle, the front wheel angle velocity, and the front wheel side slip angle as variables.

8. A control system for a steer-by-wire steering system as claimed in claim 7, characterised in that, The characteristic equation construction module is specifically configured to: derivate the steering system dynamic equation with the front wheel angle, the front wheel angle velocity, and the front wheel side slip angle as variables to obtain a Jacobian matrix, and obtain the characteristic equation and all characteristic value expressions based on the Jacobian matrix.

9. A control system for a steer-by-wire steering system as claimed in claim 8, characterised in that, The regulation module is specifically configured to: increase the magneto-rheological damper current real-time value by a set current step size.

10. A control device of a steer-by-wire system characterized by comprising: comprise: at least one processor; and a memory connected with the at least one processor in communication; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the control method of the steer-by-wire system according to any one of claims 1-5.

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