Steer-by-wire system feedback control method, device and equipment, medium and vehicle

Abstract

The embodiment of the invention provides a steering-by-wire system feedback control method, device and equipment, a medium and a vehicle, and relates to the technical field of vehicles. The method comprises the steps that the expected rotation variable quantity output to a steering wheel is determined in response to received vehicle state parameters, the expected rotation variable quantity comprises the expected torque variable quantity, the constraint condition corresponding to the expected rotation variable quantity is determined in response to a received triggering signal of the auxiliary driving function, and the auxiliary driving function is obtained based on the constraint condition and the expected torque variable quantity. And determining a first torque variable quantity distributed to the magnetorheological damper and a second torque variable quantity distributed to the permanent magnet motor, and outputting control signals to the magnetorheological damper and the permanent magnet motor based on the first torque variable quantity and the second torque variable quantity. According to the method, the problem that a wire-controlled steering system lacks the active rotation control capability and cannot meet the requirement of an advanced auxiliary driving function in the prior art is effectively solved.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a feedback control method, device, equipment, medium, and vehicle for a steer-by-wire system. Background Technology

[0002] In a vehicle's steering system, the driver perceives the vehicle's steering state through the mechanical feedback (i.e., "feel") from the steering wheel, which is crucial for driving safety and comfort. A steer-by-wire system provides continuously adjustable damping torque to simulate the feel of a traditional mechanical steering system, while simultaneously meeting the needs of different driving scenarios (such as low-speed assisted steering and high-speed stability control). Advanced driver assistance functions require the system to actively output angle and torque signals to perform operations such as automatic return to center, hands-free steering, and hazard avoidance, placing higher demands on the active control capabilities of the steer-by-wire system.

[0003] In related technologies, vehicle steer-by-wire systems use a rotating magnetorheological damper to provide a larger torque. However, the rotating magnetorheological damper can only provide passive damping torque and cannot actively drive the steering wheel to rotate. This fails to meet the needs of active rotation control in intelligent driving, resulting in insufficient availability of the steer-by-wire system. Summary of the Invention

[0004] This application provides a feedback control method, device, equipment, medium, and vehicle for a steer-by-wire system, in order to solve the problems in related technologies where steer-by-wire systems lack active rotation control capabilities and do not meet the requirements of advanced driver assistance functions.

[0005] In a first aspect, this application provides a feedback control method for a steer-by-wire system. The steer-by-wire system includes a magnetorheological damper and a permanent magnet motor. The output shafts of the magnetorheological damper and the permanent magnet motor are connected in series and connected to a steering wheel. Both the magnetorheological damper and the permanent magnet motor are used to output feedback torque. The method includes:

[0006] In response to the received vehicle state parameters, the expected change in rotation output to the steering wheel is determined. The expected change in rotation includes the expected change in torque, which includes the expected torque value output to the steering wheel that varies over time.

[0007] In response to the received trigger signal of the assisted driving function, determine the constraint conditions corresponding to the expected change in rotation, including torque constraint conditions;

[0008] Based on the constraints and the expected torque change, the first torque change allocated to the magnetorheological damper and the second torque change allocated to the permanent magnet motor are determined.

[0009] Based on the first torque change and the second torque change, control signals are output to the magnetorheological damper and the permanent magnet motor respectively. The control signals are used to make the magnetorheological damper output the torque value corresponding to the first torque change to the output shaft, and to make the permanent magnet motor output the torque value corresponding to the second torque change to the output shaft. The output shaft is used to feed back the received torque value to the steering wheel.

[0010] In one embodiment of this disclosure, the vehicle state parameters include the actual rotation angle and actual angular velocity of the steering wheel, and the expected rotation change further includes the expected angle change and the expected angular velocity change; the constraints include angle constraints and angular velocity constraints; in response to a received trigger signal of an assisted driving function, determining the constraints corresponding to the expected rotation change includes: determining the angle constraints and target angle change of the steering wheel based on the assisted driving function corresponding to the trigger signal and the expected angle change, wherein the angle constraints include a target angle range; determining the angular velocity constraints and target angular velocity change of the steering wheel based on the target angle change, the actual rotation angle, and the expected angular velocity change, wherein the angular velocity constraints include a range of angular velocity changes; and determining the torque constraints of the steering wheel based on the target angular velocity change and the actual angular velocity, wherein the torque constraints include a range of torque changes.

[0011] In one embodiment of this disclosure, determining the steering wheel angle constraint and target angle change based on the trigger signal corresponding to the assisted driving function and the expected angle change includes: determining the steering wheel rotation angle constraint based on the trigger signal corresponding to the assisted driving function; inputting the expected angle change into the angle constraint; and outputting the target angle change of the steering wheel.

[0012] In one embodiment of this disclosure, determining the angular velocity constraint condition and the target angular velocity change of the steering wheel based on the target angle change, the actual rotation angle, and the expected angular velocity change includes: determining the angle deviation change of the steering wheel based on the difference between the target angle change and the actual rotation angle; performing proportional-integral control processing on the angle deviation change to obtain the angular velocity constraint condition of the steering wheel; inputting the expected angular velocity change into the angular velocity constraint condition, and outputting the target angular velocity change of the steering wheel.

[0013] In one embodiment of this disclosure, determining the torque constraint condition of the steering wheel based on the target angular velocity change and the actual angular velocity includes: determining the angular velocity deviation change of the steering wheel based on the difference between the target angular velocity change and the actual angular velocity; and performing proportional-integral control processing on the angular velocity deviation change to obtain the torque constraint condition of the steering wheel.

[0014] In one embodiment of this disclosure, determining a first torque change allocated to the magnetorheological damper and a second torque change allocated to the permanent magnet motor based on constraints and expected torque changes includes: determining a deviation torque corresponding to the steering wheel based on the detected actual torque value and the expected torque change; if the deviation torque is less than a set deviation threshold, dividing the expected torque change into a first torque change and an expected second torque change based on a set first allocation ratio, wherein the first torque change at any given time is greater than the expected second torque change; if the deviation torque is greater than the set deviation threshold, dividing the expected torque change into a first torque change and an expected second torque change based on a set second allocation ratio and a set third allocation ratio; inputting the expected second torque change into torque constraints and outputting the second torque change.

[0015] In one embodiment of this disclosure, if the deviation torque is greater than a set deviation threshold, the expected torque change is divided into a first torque change and an expected second torque change based on a set second allocation ratio and a set third allocation ratio. This includes: if the deviation torque is greater than or equal to the set deviation threshold, dividing the initial torque value in the expected torque change into an initial first torque value and an initial second torque value based on the set second allocation ratio, wherein the initial first torque value is less than the initial second torque value; dividing the last torque value in the expected torque change into a target first torque value and a target second torque value based on the set third allocation ratio, wherein the target first torque value is greater than the target second torque value; determining the first torque change based on the initial first torque value and the target first torque value, wherein the torque value in the first torque change adjusts from the initial first torque value to the target first torque value over time; and determining the expected second torque change based on the initial second torque value and the target second torque value, wherein the torque value in the expected second torque change adjusts from the initial second torque value to the target second torque value over time.

[0016] Secondly, this disclosure provides a feedback control device for a steer-by-wire system. The steer-by-wire system includes a magnetorheological damper and a permanent magnet motor. The output shafts of the magnetorheological damper and the permanent magnet motor are connected in series and connected to a steering wheel. Both the magnetorheological damper and the permanent magnet motor are used to output feedback torque. The steer-by-wire system feedback control device includes:

[0017] The receiving module is used to determine the expected rotation change amount output to the steering wheel in response to the received vehicle state parameters. The expected rotation change amount includes the expected torque change amount, which includes the expected torque value output to the steering wheel that varies over time.

[0018] The judgment module is used to determine the constraint conditions corresponding to the expected change in rotation in response to the received trigger signal of the assisted driving function. The constraint conditions include torque constraint conditions.

[0019] The allocation module is used to determine, based on constraints and expected torque changes, a first torque change allocated to the magnetorheological damper and a second torque change allocated to the permanent magnet motor.

[0020] The output module is used to output control signals to the magnetorheological damper and the permanent magnet motor respectively based on the first torque change and the second torque change. The control signals are used to make the magnetorheological damper output the torque value corresponding to the first torque change to the output shaft, and to make the permanent magnet motor output the torque value corresponding to the second torque change to the output shaft. The output shaft is used to feed back the received torque value to the steering wheel.

[0021] Optionally, the judgment module is specifically used to: if the vehicle state parameters include the actual rotation angle and actual angular velocity of the steering wheel, and the expected rotation change includes the expected angle change and the expected angular velocity change; and the constraints include angle constraints and angular velocity constraints; based on the trigger signal corresponding to the assisted driving function and the expected angle change, determine the angle constraints and target angle change of the steering wheel, whereby the angle constraints include the target angle range; based on the target angle change, the actual rotation angle, and the expected angular velocity change, determine the angular velocity constraints and target angular velocity change of the steering wheel, whereby the angular velocity constraints include the range of angular velocity changes; and based on the target angular velocity change and the actual angular velocity, determine the torque constraints of the steering wheel, whereby the torque constraints include the range of torque changes.

[0022] In one embodiment of this disclosure, the determination module is specifically used to determine the angle constraint conditions of the steering wheel rotation angle based on the assisted driving function corresponding to the trigger signal; input the expected angle change into the angle constraint conditions; and output the target angle change of the steering wheel.

[0023] In one embodiment of this disclosure, the judgment module is specifically used to: determine the change in steering wheel angle deviation based on the difference between the target angle change and the actual rotation angle; perform proportional-integral control processing on the change in angle deviation to obtain the angular velocity constraint condition of the steering wheel; input the expected change in angular velocity into the angular velocity constraint condition, and output the target change in steering wheel angular velocity.

[0024] In one embodiment of this disclosure, the determination module is specifically used to determine the change in angular velocity deviation of the steering wheel based on the difference between the change in target angular velocity and the actual angular velocity; and to perform proportional-integral control processing on the change in angular velocity deviation to obtain the torque constraint condition of the steering wheel.

[0025] In one embodiment of this disclosure, the allocation module is specifically configured to: determine the deviation torque corresponding to the steering wheel based on the detected actual torque value and the expected torque change; if the deviation torque is less than a set deviation threshold, divide the expected torque change into a first torque change and an expected second torque change based on a set first allocation ratio, wherein the first torque change at any given time is greater than the expected second torque change; if the deviation torque is greater than the set deviation threshold, divide the expected torque change into a first torque change and an expected second torque change based on a set second allocation ratio and a set third allocation ratio; input the expected second torque change into the torque constraint condition, and output the second torque change.

[0026] In one embodiment of this disclosure, the allocation module is specifically configured to: if the deviation torque is greater than or equal to a set deviation threshold, divide the initial torque value in the expected torque change into an initial first torque value and an initial second torque value based on a set second allocation ratio, wherein the initial first torque value is less than the initial second torque value; divide the last torque value in the expected torque change into a target first torque value and a target second torque value based on a set third allocation ratio, wherein the target first torque value is greater than the target second torque value; determine a first torque change based on the initial first torque value and the target first torque value, wherein the torque value in the first torque change adjusts from the initial first torque value to the target first torque value over time; and determine an expected second torque change based on the initial second torque value and the target second torque value, wherein the torque value in the expected second torque change adjusts from the initial second torque value to the target second torque value over time.

[0027] Thirdly, embodiments of this application provide a control device, including: a memory and a processor;

[0028] The memory stores the instructions that the computer executes;

[0029] The processor executes computer execution instructions stored in memory, causing the processor to perform a feedback control method for implementing a steer-by-wire system as described in the first aspect of this disclosure.

[0030] Fourthly, embodiments of this disclosure also provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the steer-by-wire feedback control method as described in the first aspect of this disclosure.

[0031] Fifthly, embodiments of this disclosure also provide a computer program product comprising computer execution instructions, which, when executed by a processor, are used to implement the steer-by-wire system feedback control method as described in the first aspect of this disclosure.

[0032] In a sixth aspect, embodiments of this application provide a steer-by-wire system, which includes a controller, a magnetorheological damper, and a permanent magnet motor. The output shafts of the magnetorheological damper and the permanent magnet motor are connected in series and connected to a steering wheel. Both the magnetorheological damper and the permanent magnet motor are used to output feedback torque.

[0033] The controller is used to execute the steer-by-wire system feedback control method as described in the first aspect of this disclosure.

[0034] In a seventh aspect, embodiments of this application provide a vehicle that includes a steer-by-wire system as described in the sixth aspect of this disclosure.

[0035] The steer-by-wire system feedback control method, device, equipment, medium, and vehicle provided in this disclosure significantly improve the feedback performance and safety of the steer-by-wire system in advanced driver assistance functions through the coordinated control of a magnetorheological damper and a permanent magnet motor. By determining the expected torque and calculating the constraints based on vehicle state parameters and driver assistance function requirements, the output torque of both is precisely allocated. This fully leverages the complementary advantages of the high torque output of the magnetorheological damper and the fast and precise control of the permanent magnet motor, while effectively avoiding torque overload and system instability. As a result, high-precision angle and torque control of the steering wheel can be achieved, ensuring active, smooth, and reliable steering wheel rotation in driver assistance functions such as automatic parking and lane keeping, while also taking into account the feel feedback and system safety under different driving conditions. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0037] Figure 1 This diagram illustrates an application scenario of the feedback control method, apparatus, equipment, medium, and vehicle for the steer-by-wire system provided in this embodiment of the disclosure.

[0038] Figure 2 A flowchart of a feedback control method for a steer-by-wire system provided in one embodiment of this disclosure;

[0039] Figure 3 A flowchart of a feedback control method for a steer-by-wire system provided in yet another embodiment of this disclosure;

[0040] Figure 4 A schematic diagram of the structure of a feedback control device for a steer-by-wire system provided in yet another embodiment of this disclosure;

[0041] Figure 5 This is a schematic diagram of the structure of a control device provided in yet another embodiment of the present disclosure;

[0042] Figure 6A schematic diagram of the structure of a steer-by-wire system provided in yet another embodiment of this disclosure;

[0043] Figure 7 This is a structural schematic diagram of a vehicle provided for yet another embodiment of this disclosure.

[0044] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0045] 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 numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0046] New energy vehicles and vehicles equipped with intelligent driving assistance systems are typically equipped with a variety of driver assistance functions, such as automatic parking, lane keeping, and emergency obstacle avoidance. These functions require precise active control of the steering wheel to accurately adjust the vehicle's driving direction. In this case, the steer-by-wire system must not only provide sufficient feedback torque to ensure steering execution force, but also ensure smooth adjustment of output torque to avoid abruptness during vehicle operation. Furthermore, it must have continuous and stable torque output capability to ensure the continuity of control and driving safety in various driving scenarios.

[0047] In related technologies, steer-by-wire systems typically use a single magnetorheological damper or a conventional motor as the feedback actuator, which makes it difficult to simultaneously meet the aforementioned requirements. While magnetorheological dampers can output a large damping torque, their response speed is limited, making it difficult to achieve high-precision, smooth torque adjustment, and they cannot actively drive rotation. On the other hand, while conventional motors offer high control precision, they are prone to overheating when continuously outputting large torques, and their torque output range is limited. As a result, steer-by-wire systems cannot simultaneously achieve high torque output, smoothness, and continuous stability, making it difficult to meet the functional requirements of advanced autonomous driving.

[0048] The steer-by-wire system feedback control method, device, equipment, medium, and vehicle provided in this application work together by connecting a magnetorheological damper and a permanent magnet synchronous motor in series. Based on the driver assistance function trigger signal and vehicle status, the expected torque and its constraints are dynamically calculated. The torque to be fed back to the steering wheel is then distributed as a first torque change of the magnetorheological damper and a second torque change of the permanent magnet motor, which are output by the two actuators respectively. This simultaneously achieves high torque output, high-precision smooth adjustment, and continuous stable control of the steering wheel feedback torque.

[0049] Figure 1 The diagram illustrates the application scenarios of the feedback control method, device, equipment, medium, and vehicle for the steer-by-wire system provided in this application. Figure 1 As shown, in the feedback control of the steer-by-wire system, the vehicle-mounted steer-by-wire system 100 receives the signal output by the vehicle-mounted controller 110 and outputs the corresponding torque to the steering wheel 120 inside the vehicle, thereby realizing the function of feedback control based on the action of the steering wheel 120 inside the vehicle.

[0050] It should be noted that, Figure 1 The scenario shown includes an onboard steer-by-wire system, an onboard controller, and an in-vehicle steering wheel, which are only illustrated by one or a specific number of examples. However, this disclosure is not limited to this. In other words, the number of onboard steer-by-wire systems, onboard controllers, and in-vehicle steering wheels can be arbitrary.

[0051] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0052] Figure 2 This is a flowchart illustrating the feedback control method for the steer-by-wire system provided in the embodiments of this application. The following is a summary of the process. Figure 2 The main process of the feedback control method for steer-by-wire systems is explained below:

[0053] S201. In response to the received vehicle state parameters, determine the expected change in steering wheel rotation.

[0054] The expected rotational change includes the expected torque change, which includes the expected torque value that is output to the steering wheel over time.

[0055] The steer-by-wire system in this embodiment includes a magnetorheological damper and a permanent magnet motor. The output shafts of the magnetorheological damper and the permanent magnet motor are connected in series and connected to the steering wheel. Both the magnetorheological damper and the permanent magnet motor are used to output feedback torque.

[0056] Specifically, the feedback control method in this embodiment is applied to a steer-by-wire system in a vehicle. The steer-by-wire system is equipped with both a magnetorheological damper and a permanent magnet motor. The torque is output through these two devices and fed back to the steering wheel, so that the driver feels the damping torque when controlling the steering wheel, thereby simulating the feel of a mechanical steering system.

[0057] The magnetorheological damper is a rotary magnetorheological damper used to output rotational torque. It changes the magnetic field strength in the internal magnetorheological fluid by inputting a control current, thereby altering the viscosity characteristics and enabling the damper to output different magnitudes of rotational damping torque. Since the output control current is used to change the magnetic field strength, thus altering the viscosity characteristics of the magnetorheological fluid, and only a small control current is needed to significantly change these characteristics, resulting in a significant change in the rotational damping torque output by the damper, a larger torque can be achieved with a smaller control current, improving control efficiency.

[0058] In contrast, a permanent magnet motor is a permanent magnet synchronous motor. It receives control currents of different magnitudes to establish a working magnetic field in the three-phase stator windings, which interacts with the rotor permanent magnets to generate magnetic field torque, and then outputs torque. Therefore, the magnitude of the control current is directly related to the magnitude of the magnetic field and the magnitude of the magnetic field torque. Thus, a larger control current is required when outputting a larger torque.

[0059] However, since changes in the control current in a permanent magnet motor can directly drive changes in the output torque, its response speed is relatively fast. In contrast, changes in the control current in a magnetorheological damper are first converted into changes in the viscosity characteristics of the magnetorheological fluid, and then into changes in the output torque. Therefore, the response speed of a permanent magnet motor is faster than that of a magnetorheological damper.

[0060] Therefore, by combining the two devices mentioned above in the steer-by-wire system, the advantages of the permanent magnet motor in terms of fast response speed and continuous and accurate adjustment can be utilized, while the advantage of the magnetorheological damper in terms of outputting large damping torque with only a small current can be utilized. This effectively solves the problems of high power consumption and easy overheating risk in the steer-by-wire system in related technologies.

[0061] The following describes the specific feedback control process and method steps of the steer-by-wire system in conjunction with the method steps in this embodiment and subsequent embodiments.

[0062] It should be noted that the entity executing the feedback control method is the control module or controller in the steer-by-wire system. It can be a control system or control unit (such as an ECU) that works with the steer-by-wire system in the vehicle. For ease of explanation, it will be referred to as the controller from now on.

[0063] After the vehicle is woken up or started, the controller will continuously monitor the vehicle's status parameters, such as the vehicle's driving status (e.g., speed, acceleration) and driving mode (e.g., gear, sport mode). Based on this data, it can calculate the ideal motion trajectory of the steering wheel to achieve a specific driving intention or assistance function, and output the torque change as the final output. For example, in automatic parking, the vehicle's driving trajectory needs to be determined based on the position of the parking space and the vehicle's position, and then the corresponding motion trajectory of the steering wheel throughout the process needs to be determined.

[0064] Vehicle status parameters typically include the current steering wheel angle, angular velocity, vehicle speed, and yaw rate. The vehicle's main controller (such as the VCU or dedicated ECU, i.e., the host computer within the vehicle) can use these parameters and built-in functional algorithm models (such as lane-keeping models and automatic parking trajectory models) to calculate and ultimately generate a sequence of instructions indicating how the steering wheel should move—the expected change in rotation. This change includes the expected change in angle or angular velocity, but during execution, it is converted into torque that directly drives the actuators at the lower level. This torque is described in detail as a time-varying curve (such as gradient rise, hold, and fall) to ensure smooth and precise control.

[0065] The expected torque change is not a fixed value, but a continuous target curve that defines the magnitude, direction, and time of torque change. For example, at the beginning of automatic parking, the expected torque change might be a curve that gradually increases from zero torque to a certain positive torque value, instructing the steering wheel to begin rotating smoothly to the right.

[0066] S202. In response to the received trigger signal of the driver assistance function, determine the constraint conditions corresponding to the expected change in rotation.

[0067] Among these constraints are torque constraints.

[0068] Specifically, the trigger signal is used to indicate the currently activated driver assistance function (such as LKA lane keeping assist, APA automatic parking assist, AES automatic emergency steering, and DSR dynamic steering response). Different functions have unique safety requirements and operating characteristics for the steering wheel's range of motion, speed, and torque.

[0069] In some embodiments, in addition to driver assistance functions, trigger signals for basic driving functions can also be used to determine corresponding constraints, such as the reversing function.

[0070] Based on this signal, the controller invokes a pre-set set of constraints that match the function. These constraints are then integrated with the aforementioned expected rotational change to protect the system's mechanical structure, prevent system malfunction, and ensure driving comfort.

[0071] The torque constraint directly limits the maximum and minimum torque values ​​that can be output to the steering wheel, preventing damage to the steering mechanism or discomfort or even injury to the driver's arms due to excessive torque.

[0072] For example, in Comfort mode, the torque limit may be set lower to provide a gentle feel; while in Emergency Obstacle Avoidance mode, the limit will be increased to ensure that there is enough force to quickly complete the obstacle avoidance maneuver.

[0073] The process of determining constraints can be achieved through dynamic table lookup or real-time calculation. By quickly determining constraints, it can be ensured that the subsequent output control signals are limited to a predefined, safe range.

[0074] S203. Based on the constraints and the expected torque change, determine the first torque change to be allocated to the magnetorheological damper and the second torque change to be allocated to the permanent magnet motor.

[0075] Specifically, based on the overall expected torque demand calculated in the aforementioned steps, the controller will decompose it into sub-tasks to be undertaken by the two actuators respectively. During the allocation process, the torque constraints set in the migration steps must be followed to ensure that the resultant force output does not exceed the safe range.

[0076] The allocation principle is based on the inherent characteristics of the two actuators:

[0077] Magnetorheological dampers excel at providing large damping forces and rapidly dissipating kinetic energy, making them suitable for handling basic, high-load damping torque components (the first torque change); while permanent magnet motors offer high control precision and fast dynamic response, making them suitable for handling active torque components (the second torque change) that require fine adjustment.

[0078] The controller will calculate the optimal allocation ratio based on the specific form of the expected torque change (such as the required torque magnitude and rate of change) and the current state of the two actuators, using preset rules (which can be a specific allocation algorithm, such as real-time calculation based on weight factors, or a lookup method based on the proportional relationship obtained through experiments).

[0079] This ensures that, while meeting the total torque requirements, the advantages of the magnetorheological fluid damper in providing stable resistance and the advantages of the permanent magnet motor in precise control are fully utilized.

[0080] S204, based on the first torque change and the second torque change, outputs control signals to the magnetorheological damper and the permanent magnet motor respectively.

[0081] The control signal is used to cause the magnetorheological damper to output a torque value corresponding to the first torque change to the output shaft, and to cause the permanent magnet motor to output a torque value corresponding to the second torque change to the output shaft. The output shaft is used to feed back the received torque value to the steering wheel.

[0082] Specifically, the system generates two independent control signals. One of them is sent to the excitation current controller of the magnetorheological damper, which precisely controls the magnetic field strength by adjusting the current input to the damper coil, thereby generating a damping torque corresponding to the first torque change.

[0083] Another signal is sent to the servo driver of the permanent magnet motor, which is a torque command or current command (in torque control mode) to make the drive motor rotor output an active torque that corresponds to the second torque change.

[0084] These two torques are superimposed on their series-connected output shafts, ultimately combining to form a total, controlled feedback torque that acts on the steering wheel.

[0085] This enables parallel and coordinated control of the two actuators, ensuring that the force output to the driver is smooth, stable, and precisely meets functional requirements, thus completing the closed loop from decision-making to physical execution.

[0086] The steer-by-wire system feedback control method provided in this application significantly improves the feedback performance and safety of the steer-by-wire system in advanced driver assistance functions through the coordinated control of a magnetorheological damper and a permanent magnet motor. By determining the expected torque and calculating the constraints based on vehicle state parameters and driver assistance function requirements, the output torque of both is precisely allocated. This fully leverages the complementary advantages of the high torque output of the magnetorheological damper and the fast and precise control of the permanent magnet motor, while effectively avoiding torque overload and system instability. As a result, high-precision angle and torque control of the steering wheel can be achieved, ensuring active, smooth, and reliable steering wheel rotation in driver assistance functions such as automatic parking and lane keeping, while also taking into account the feel feedback and system safety under different driving conditions.

[0087] Figure 3 Another embodiment of the steer-by-wire system feedback control method provided in this disclosure, in Figure 2 Based on the illustrated embodiment, the following is combined with Figure 3 The implementation process of the feedback control method for the steer-by-wire system is explained in detail, including the following steps:

[0088] S301. In response to the received vehicle state parameters, determine the expected change in steering wheel rotation.

[0089] The expected rotational change includes the expected torque change, which includes the expected torque value that is output to the steering wheel over time.

[0090] Specifically, as described in the preceding embodiments, the host computer continuously monitors and receives vehicle state parameters such as the actual steering wheel rotation angle and actual angular velocity. Based on the currently activated assisted driving function target (such as the need for straightening during lane keeping), it calculates and generates the expected rotation change amount through a built-in algorithm model. This amount includes an expected torque curve that changes over time. The relevant content is described in step S201 and will not be repeated here.

[0091] S302. Based on the trigger signal corresponding to the assisted driving function and the expected angle change, determine the steering wheel angle constraint and the target angle change.

[0092] Among them, the angle constraint conditions include the target angle range.

[0093] Specifically, in this embodiment, the vehicle state parameters include the actual rotation angle and actual angular velocity of the steering wheel, and the expected rotation change also includes the expected angle change and the expected angular velocity change; the constraints include angle constraints and angular velocity constraints.

[0094] Based on the specific driver assistance function corresponding to the trigger signal, the controller determines the safe angle boundary (angle constraint) for steering wheel rotation. The calculated expected angle change is input into this constraint for limiting processing, and the output is an achievable target angle change that is restricted within a safe range.

[0095] Furthermore, the specific steps for determining the angle constraints include:

[0096] Step A1: Based on the trigger signal corresponding to the assisted driving function, determine the angle constraint conditions for the steering wheel rotation angle.

[0097] Specifically, the controller is pre-configured with a mapping table of corresponding functions and angle constraints according to different functions (such as APA or LKA). By querying this table, the maximum and minimum steering wheel rotation angle limits allowed by the assisted driving function can be obtained, i.e., the angle constraints.

[0098] Step A2: Input the expected angle change into the angle constraint conditions and output the target angle change of the steering wheel.

[0099] Specifically, the controller compares the original expected angle change calculated by the host computer with the aforementioned angle constraints. If it exceeds the limit, it is trimmed to the limit value, and finally outputs the target angle change after safety limiting to prevent the expected angle change from being too large and affecting the system's safety.

[0100] S303. Based on the target angle change, the actual rotation angle, and the expected angular velocity change, determine the angular velocity constraint conditions and the target angular velocity change of the steering wheel.

[0101] The angular velocity constraint includes the range of angular velocity variation.

[0102] Specifically, the controller uses the deviation between the target angle change obtained in the previous step and the actual rotation angle monitored in real time (which can be detected by the steering wheel angle sensor) to generate angular velocity constraints through the control algorithm, and combines them with the expected angular velocity change to finally derive a restricted target angular velocity change.

[0103] Furthermore, the specific steps for obtaining the angular velocity constraint conditions include:

[0104] Step B1: Determine the change in steering wheel angle based on the difference between the target angle change and the actual rotation angle.

[0105] Specifically, the controller calculates the difference between the angle value at each moment in the target angle change and the actual rotation angle of the steering wheel, thus obtaining the angle deviation change.

[0106] Step B2: Perform proportional-integral control processing on the change in angle deviation to obtain the angular velocity constraint condition of the steering wheel.

[0107] Specifically, the controller performs proportional-integral (PI) control calculations on the change in angular deviation, and the output result is converted to obtain the allowable range of angular velocity variation, i.e., the angular velocity constraint condition.

[0108] Step B3: Input the expected change in angular velocity into the angular velocity constraint condition, and output the target change in angular velocity of the steering wheel.

[0109] Specifically, the controller inputs the expected angular velocity change output from the host computer into the angular velocity constraint conditions for amplitude limiting. It will output the target angular velocity change that does not exceed the safe range to prevent oversaturation during proportional-integral control, which would affect the control accuracy and results.

[0110] S304. Based on the change in target angular velocity and the actual angular velocity, determine the torque constraint conditions for the steering wheel.

[0111] The torque constraint includes the range of torque variation.

[0112] Specifically, the controller determines the final torque constraint based on the difference between the target angular velocity change and the actual angular velocity value collected by the sensor.

[0113] Furthermore, the specific method for determining the torque constraint conditions includes the following steps:

[0114] Step C1: Determine the change in steering wheel angular velocity deviation based on the difference between the target angular velocity change and the actual angular velocity.

[0115] Specifically, the controller calculates the difference between the angular velocity value at each moment in the target angular velocity change and the vehicle's actual angular velocity, thus obtaining the angular velocity deviation change.

[0116] Step C2: Perform proportional-integral control processing on the change in angular velocity deviation to obtain the torque constraint condition of the steering wheel.

[0117] Specifically, the controller performs proportional-integral (PI) control calculations on the change in angular velocity deviation, and the output result can be used as the upper and lower limits of torque output, i.e., torque constraint conditions.

[0118] S305. Based on the detected actual torque value and the expected torque change, determine the corresponding deviation torque of the steering wheel.

[0119] Specifically, the controller reads the actual torque value on the steering wheel (which can be collected by the torque sensor configured in the steer-by-wire system) and calculates the difference between it and the torque value at each moment in the expected torque change output by the host computer. The deviation torque between the two can be calculated (the deviation torque is also a quantity that changes over time).

[0120] S306. If the deviation torque is less than the set deviation threshold, based on the set first distribution ratio, the expected torque change is divided into a first torque change and an expected second torque change.

[0121] Among them, the change in the first torque at the same moment is greater than the expected change in the second torque.

[0122] Specifically, if the calculated deviation torque is less than the preset threshold (e.g., the deviation torque is always less than 1 Nm), it indicates that the current state is stable. The controller can then use a preset first allocation ratio (e.g., any ratio such as 70%:30%, 90%:10%) to decompose the expected torque change into the first torque change borne by the magnetorheological damper and the expected second torque change borne by the permanent magnet motor. In this case, the damper shares a larger proportion of the torque.

[0123] S307. If the deviation torque is greater than the set deviation threshold, based on the set second distribution ratio and the set third distribution ratio, the expected torque change is divided into the first torque change and the expected second torque change.

[0124] Specifically, if the deviation torque is greater than the preset threshold (e.g., greater than 1Nm~3Nm), it indicates that the output torque needs to be adjusted quickly. At this time, the controller will adopt a dynamic allocation strategy and calculate the torque sharing of the two actuators in segments according to different ratios.

[0125] Furthermore, the torque distribution calculation method when the deviation torque is large includes:

[0126] Step D1: If the deviation torque is greater than or equal to the set deviation threshold, based on the set second allocation ratio, the initial torque value in the expected torque change is divided into an initial first torque value and an initial second torque value.

[0127] The initial first torque value is less than the initial second torque value.

[0128] Specifically, compared to the previous scenario, the permanent magnet motor needs to output a larger torque first for a rapid response, thus achieving a precise and fast response (the magnetorheological damper can provide a sufficiently large torque with a smaller current, but its accuracy is not high and its response speed is slower than that of the permanent magnet motor, while the permanent magnet motor can provide precise torque, but it suffers from severe heat generation, resulting in a poor driver experience; therefore, in this case, the permanent magnet motor is used to quickly provide a larger and more accurate torque). At this point, the permanent magnet motor needs to output a sufficiently large torque, i.e., the initial second torque value. Therefore, the initial second torque value is much larger than the initial first torque value (for example, the ratio of the initial first torque value to the initial second torque value, i.e., the second set allocation ratio, can be 1:9 or 1:10).

[0129] Step D2: Based on the set third allocation ratio, the last torque value in the expected torque change is divided into the target first torque value and the target second torque value.

[0130] Among them, the first target torque value is greater than the second target torque value.

[0131] Specifically, after the permanent magnet motor rapidly increases from the actual torque value to the initial second torque value, the magnetorheological damper will gradually take over the output operation. At this time, the torque value output by the permanent magnet motor will decrease from the initial second torque value to the target second torque value, while the magnetorheological damper will increase from the initial first torque value to the target first torque value.

[0132] At this point, the target first torque value is usually much larger than the target second torque value. For example, the third set distribution ratio can be 10:1 or 9:1.

[0133] Step D3: Determine the change in first torque based on the initial first torque value and the target first torque value.

[0134] Among them, the torque value in the first torque change amount is adjusted from the initial first torque value to the target first torque value over time.

[0135] Specifically, based on the initial first torque value and the target first torque value, the controller can use linear or specific curve interpolation to generate a first torque change that transitions smoothly over time, indicating how the magnetorheological damper gradually increases from the initial first torque value to the target first torque value.

[0136] Step D4: Based on the initial second torque value and the target second torque value, determine the expected change in second torque.

[0137] Among them, the torque value in the expected second torque change adjusts from the initial second torque value to the target second torque value over time.

[0138] Specifically, the controller can also use interpolation to generate the expected change in the second torque based on the initial second torque value and the target second torque value, instructing the permanent magnet motor to gradually decrease from the larger initial second torque value to the smaller target second torque value.

[0139] S308. Input the expected second torque change into the torque constraint condition and output the second torque change.

[0140] Specifically, since permanent magnet motors have advantages such as fast response and precise changes, the expected second torque change obtained in the previous step can be input into the torque constraint conditions determined in step S304 to limit the expected second torque change, ensuring that the motor output torque is always within a safe range, and finally outputting the actual second torque change to be executed by the permanent magnet motor.

[0141] In some embodiments, the expected first torque change can also be input into the torque constraint condition for limiting processing. Alternatively, the expected torque change can be input into the torque constraint condition in advance for limiting processing. The principle is the same as above, and will not be elaborated here.

[0142] S309, based on the first torque change and the second torque change, outputs control signals to the magnetorheological damper and the permanent magnet motor respectively.

[0143] The control signal is used to cause the magnetorheological damper to output a torque value corresponding to the first torque change to the output shaft, and to cause the permanent magnet motor to output a torque value corresponding to the second torque change to the output shaft. The output shaft is used to feed back the received torque value to the steering wheel.

[0144] Specifically, the controller sends two independent control signals to the drivers of the magnetorheological damper and the permanent magnet motor, respectively. One signal drives the damper to output its corresponding first torque change, and the other signal drives the motor to output its corresponding second torque change. The two signals are combined on the output shaft to ultimately transmit the resultant torque to the steering wheel, achieving precise, safe, and smooth steering feedback control.

[0145] In some embodiments, when the vehicle is in APA mode, if the driver is in a completely hands-free state, the first torque change input from the host computer to the magnetorheological damper is fixed at 0. At this time, the magnetorheological damper does not work to ensure the control accuracy of the steer-by-wire system (all torque output and control are performed through the permanent magnet motor).

[0146] In some embodiments, when the vehicle is not in APA mode and the driver has not completely taken his hands off the wheel, it is first necessary to monitor whether the driver's hands are on the steering wheel (i.e. whether the torque sensor detects the real-time actual torque value). If so, the corresponding control signal can be output directly based on the first torque change obtained in the aforementioned steps.

[0147] If it is detected that the driver's hands are not on the steering wheel (i.e., the detected real-time actual torque value is 0), the first torque change is fixed at 0. At this time, by making the magnetorheological damper not work and only the permanent magnet motor works, precise control in various working conditions and attack-assisted driving functions can be achieved, so that the permanent magnet motor drives the steering wheel to rotate with minimum torque, while ensuring the driver's hand feel when necessary.

[0148] The steer-by-wire system feedback control method provided in this disclosure ensures the safety and smoothness of the active steering wheel control process by introducing multi-level constraints of angle, angular velocity, and torque, along with proportional-integral control. Through a dynamic torque distribution strategy based on deviation torque, it coordinates the output characteristics of the magnetorheological damper and the permanent magnet motor, fully leveraging the former's high load capacity and the latter's precise control advantages, while achieving a balance between high torque output and high-precision adjustment. This enables the steer-by-wire system to provide stable, reliable force feedback that aligns with the driver's intentions in various assisted driving scenarios, significantly improving the system's control performance, safety margin, and driving experience.

[0149] Figure 4 This is a schematic diagram of the structure of a feedback control device for a steer-by-wire system according to an embodiment of this disclosure. Figure 4 As shown, the steer-by-wire system feedback control device 400 is applied to the steer-by-wire system, which includes a magnetorheological damper and a permanent magnet motor. The output shafts of the magnetorheological damper and the permanent magnet motor are connected in series and connected to the steering wheel. Both the magnetorheological damper and the permanent magnet motor are used to output feedback torque. The steer-by-wire system feedback control device 400 includes:

[0150] The receiving module 410 is used to determine the expected rotation change amount output to the steering wheel in response to the received vehicle state parameters. The expected rotation change amount includes the expected torque change amount, which includes the expected torque value output to the steering wheel that changes over time.

[0151] The judgment module 420 is used to determine the constraint conditions corresponding to the expected change in rotation in response to the received trigger signal of the assisted driving function. The constraint conditions include torque constraint conditions.

[0152] The allocation module 430 is used to determine, based on constraints and expected torque changes, a first torque change to be allocated to the magnetorheological damper and a second torque change to be allocated to the permanent magnet motor.

[0153] The output module 440 is used to output control signals to the magnetorheological damper and the permanent magnet motor respectively based on the first torque change and the second torque change. The control signals are used to make the magnetorheological damper output the torque value corresponding to the first torque change to the output shaft, and to make the permanent magnet motor output the torque value corresponding to the second torque change to the output shaft. The output shaft is used to feed back the received torque value to the steering wheel.

[0154] Optionally, the judgment module 420 is specifically used to: if the vehicle state parameters include the actual rotation angle and actual angular velocity of the steering wheel, and the expected rotation change includes the expected angle change and the expected angular velocity change; and the constraints include angle constraints and angular velocity constraints; based on the trigger signal corresponding to the assisted driving function and the expected angle change, determine the angle constraints and target angle change of the steering wheel, wherein the angle constraints include the target angle range; based on the target angle change, the actual rotation angle, and the expected angular velocity change, determine the angular velocity constraints and target angular velocity change of the steering wheel, wherein the angular velocity constraints include the range of angular velocity changes; and based on the target angular velocity change and the actual angular velocity, determine the torque constraints of the steering wheel, wherein the torque constraints include the range of torque changes.

[0155] In one embodiment of this disclosure, the judgment module 420 is specifically used to determine the angle constraint condition of the steering wheel rotation angle based on the assisted driving function corresponding to the trigger signal; input the expected angle change into the angle constraint condition; and output the target angle change of the steering wheel.

[0156] In one embodiment of this disclosure, the judgment module 420 is specifically used to: determine the change in steering wheel angle deviation based on the difference between the target angle change and the actual rotation angle; perform proportional-integral control processing on the change in angle deviation to obtain the angular velocity constraint condition of the steering wheel; input the expected change in angular velocity into the angular velocity constraint condition, and output the target change in steering wheel angular velocity.

[0157] In one embodiment of this disclosure, the determination module 420 is specifically used to determine the change in angular velocity deviation of the steering wheel based on the difference between the change in target angular velocity and the actual angular velocity; and to perform proportional-integral control processing on the change in angular velocity deviation to obtain the torque constraint condition of the steering wheel.

[0158] In one embodiment of this disclosure, the allocation module 430 is specifically configured to: determine the deviation torque corresponding to the steering wheel based on the detected actual torque value and the expected torque change; if the deviation torque is less than a set deviation threshold, divide the expected torque change into a first torque change and an expected second torque change based on a set first allocation ratio, wherein the first torque change at any given time is greater than the expected second torque change; if the deviation torque is greater than the set deviation threshold, divide the expected torque change into a first torque change and an expected second torque change based on a set second allocation ratio and a set third allocation ratio; input the expected second torque change into the torque constraint condition, and output the second torque change.

[0159] In one embodiment of this disclosure, the allocation module 430 is specifically configured to: if the deviation torque is greater than or equal to a set deviation threshold, divide the initial torque value in the expected torque change into an initial first torque value and an initial second torque value based on a set second allocation ratio, wherein the initial first torque value is less than the initial second torque value; divide the last torque value in the expected torque change into a target first torque value and a target second torque value based on a set third allocation ratio, wherein the target first torque value is greater than the target second torque value; determine a first torque change based on the initial first torque value and the target first torque value, wherein the torque value in the first torque change adjusts from the initial first torque value to the target first torque value over time; and determine an expected second torque change based on the initial second torque value and the target second torque value, wherein the torque value in the expected second torque change adjusts from the initial second torque value to the target second torque value over time.

[0160] The relevant explanations can be understood by referring to the corresponding descriptions and effects in the method embodiments, and will not be repeated here.

[0161] Figure 5 This is a schematic diagram of the structure of a control device provided in one embodiment of the present disclosure, as shown below. Figure 5 As shown, the control device 500 includes a memory 510 and a processor 520.

[0162] The memory 510 stores a computer program that can be executed by at least one processor 520. This computer program is executed by at least one processor 520 to enable the control device to implement the steer-by-wire feedback control method provided in any of the above embodiments.

[0163] The memory 510 and the processor 520 can be connected via a bus 530.

[0164] The relevant explanations can be understood by referring to the corresponding descriptions and effects in the method embodiments, and will not be repeated here.

[0165] Figure 6This is a schematic diagram of the structure of a steer-by-wire system provided in one embodiment of the present disclosure, as shown below. Figure 6 As shown, the steer-by-wire system 600 includes: a controller 610, a magnetorheological damper 620 and a permanent magnet motor 630. The output shafts of the magnetorheological damper 620 and the permanent magnet motor 630 are connected in series and connected to the steering wheel 640. Both the magnetorheological damper 620 and the permanent magnet motor 630 are used to output feedback torque.

[0166] The controller 610 is used to execute the steer-by-wire system feedback control method provided in any of the above embodiments.

[0167] Specifically, the equipment corresponding to the steer-by-wire system 600 also includes an external power supply 650 and a torque sensor 660. The external motor 650 is used to power the steer-by-wire system 600. The torque sensor 660, together with the output shaft of the magnetorheological damper 620 and the permanent magnet motor 630, is mounted on the corresponding output shaft of the steering wheel 640 to monitor the torque output by the steering wheel 640 and output the monitoring results to the controller 610.

[0168] The system is also connected to a host computer 670. For related information, please refer to the relevant descriptions and effects in the method embodiments. They will not be repeated here.

[0169] Figure 7 This is a schematic diagram of the structure of a vehicle provided in one embodiment of the present disclosure, such as... Figure 7 As shown, one embodiment of this disclosure provides a vehicle 700, which is equipped with the steer-by-wire system 600 described in the above embodiments. Related descriptions and effects can be understood from the corresponding descriptions and effects in the foregoing embodiments, and will not be repeated here.

[0170] One embodiment of this disclosure provides a computer-readable storage medium having a computer program stored thereon, the computer program being executed by a processor to implement the steer-by-wire system feedback control method provided in any of the above embodiments.

[0171] The computer-readable storage medium may be ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0172] One embodiment of this disclosure provides a computer program product comprising computer-executable instructions that, when executed by a processor, are used to implement the steer-by-wire system feedback control method provided in any of the above embodiments.

[0173] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0174] In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0175] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0176] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A feedback control method for a steer-by-wire system, characterized by, The steer-by-wire system comprises a magneto-rheological damper and a permanent magnet motor, output shafts of the magneto-rheological damper and the permanent magnet motor are connected in series and connected with a steering wheel, the magneto-rheological damper and the permanent magnet motor are both used to output feedback torque, and the method comprises the following steps: In response to the received vehicle state parameters, an expected rotation change amount output to the steering wheel is determined, the expected rotation change amount comprises an expected torque change amount, and the expected torque change amount comprises an expected torque value along time change output to the steering wheel; In response to the received trigger signal of the auxiliary driving function, a constraint condition corresponding to the expected rotation change amount is determined, and the constraint condition comprises a torque constraint condition; Based on the constraint condition and the expected torque change amount, a first torque change amount allocated to the magneto-rheological damper and a second torque change amount allocated to the permanent magnet motor are determined; Based on the first torque change amount and the second torque change amount, control signals are output to the magneto-rheological damper and the permanent magnet motor respectively, the control signals are used to make the magneto-rheological damper output a torque value corresponding to the first torque change amount to the output shaft and make the permanent magnet motor output a torque value corresponding to the second torque change amount to the output shaft, and the output shaft is used to feed back the received torque value to the steering wheel.

2. The method of claim 1, wherein, The vehicle state parameters comprise an actual rotation angle and an actual angular velocity of the steering wheel, the expected rotation change amount further comprises an expected angle change amount and an expected angular velocity change amount, and the constraint condition comprises an angle constraint condition and an angular velocity constraint condition; In response to the received trigger signal of the auxiliary driving function, a constraint condition corresponding to the expected rotation change amount is determined, and the constraint condition comprises a torque constraint condition; Based on the auxiliary driving function corresponding to the trigger signal and the expected angle change amount, an angle constraint condition of the steering wheel and a target angle change amount are determined, and the angle constraint condition comprises a target angle range; Based on the target angle change amount, the actual rotation angle and the expected angular velocity change amount, an angular velocity constraint condition of the steering wheel and a target angular velocity change amount are determined, and the angular velocity constraint condition comprises a change range of the angular velocity; Based on the target angular velocity change amount and the actual angular velocity, a torque constraint condition of the steering wheel is determined, and the torque constraint condition comprises a change range of the torque.

3. The method of claim 2, wherein, The determination of the angle constraint condition of the steering wheel and the target angle change amount based on the auxiliary driving function corresponding to the trigger signal and the expected angle change amount comprises: Based on the auxiliary driving function corresponding to the trigger signal, an angle constraint condition of the rotation angle of the steering wheel is determined; The target angle change amount of the steering wheel is output by inputting the expected angle change amount into the angle constraint condition.

4. The method of claim 3, wherein, The determination of the angular velocity constraint condition of the steering wheel and the target angular velocity change amount based on the target angle change amount, the actual rotation angle and the expected angular velocity change amount comprises: Based on a difference between the target angle change amount and the actual rotation angle, an angle deviation change amount of the steering wheel is determined; The angle deviation change amount is subjected to proportional integral control processing to obtain the angular velocity constraint condition of the steering wheel; The target angular velocity change amount of the steering wheel is output by inputting the expected angular velocity change amount into the angular velocity constraint condition.

5. The method of claim 4, wherein, The torque constraint condition of the steering wheel is determined based on the target angular velocity variation and the actual angular velocity, and the torque constraint condition of the steering wheel includes: The angular velocity deviation variation of the steering wheel is determined based on the difference between the target angular velocity variation and the actual angular velocity; The angular velocity deviation variation is subjected to proportional integral control processing to obtain the torque constraint condition of the steering wheel.

6. The method according to any one of claims 1 to 5, characterized in that, Based on the constraint condition and the expected torque variation, the first torque variation allocated to the magnetorheological damper and the second torque variation allocated to the permanent magnet motor are determined, including: Based on the detected actual torque value and the expected torque variation, the deviation torque corresponding to the steering wheel is determined; If the deviation torque is less than a set deviation threshold, the expected torque variation is divided into the first torque variation and an expected second torque variation based on a set first allocation ratio, wherein the first torque variation at the same time is greater than the expected second torque variation; If the deviation torque is greater than the set deviation threshold, the expected torque variation is divided into the first torque variation and the expected second torque variation based on a set second allocation ratio and a set third allocation ratio; The expected second torque variation is input to the torque constraint condition, and the second torque variation is output.

7. The method of claim 6, wherein, If the deviation torque is greater than the set deviation threshold, the expected torque variation is divided into the first torque variation and the expected second torque variation based on a set second allocation ratio and a set third allocation ratio, including: If the deviation torque is greater than or equal to the set deviation threshold, the initial torque value in the expected torque variation is divided into an initial first torque value and an initial second torque value based on a set second allocation ratio, wherein the initial first torque value is less than the initial second torque value; Based on a set third allocation ratio, the last torque value in the expected torque variation is divided into a target first torque value and a target second torque value, wherein the target first torque value is greater than the target second torque value; Based on the initial first torque value and the target first torque value, the first torque variation is determined, and the torque value in the first torque variation is adjusted from the initial first torque value to the target first torque value over time; Based on the initial second torque value and the target second torque value, the expected second torque variation is determined, and the torque value in the expected second torque variation is adjusted from the initial second torque value to the target second torque value over time.

8. A steer-by-wire system feedback control device, characterized by, The steer-by-wire system includes a magnetorheological damper and a permanent magnet motor, the output shafts of the magnetorheological damper and the permanent magnet motor are connected in series and connected with a steering wheel, and the magnetorheological damper and the permanent magnet motor are both used to output feedback torque, and the steer-by-wire system feedback control device includes: A receiving module is configured to determine an expected rotation variation output to the steering wheel in response to received vehicle state parameters, wherein the expected rotation variation includes an expected torque variation, and the expected torque variation includes a torque value expected to be output to the steering wheel over time. determining, in response to the received trigger signal of the auxiliary driving function, a constraint condition corresponding to the expected rotation change amount, the constraint condition including a torque constraint condition; determining, based on the constraint condition and the expected torque change amount, a first torque change amount allocated to the magnetorheological damper and a second torque change amount allocated to the permanent magnet motor; outputting, based on the first torque change amount and the second torque change amount, control signals to the magnetorheological damper and the permanent magnet motor respectively, the control signals being used to make the magnetorheological damper output a torque value corresponding to the first torque change amount to an output shaft and make the permanent magnet motor output a torque value corresponding to the second torque change amount to the output shaft, the output shaft being used to feed back the received torque value to the steering wheel.

9. A control device characterized by comprising: comprising: a memory, a processor; the memory stores computer execution instructions; the processor executes the computer execution instructions stored in the memory, so that the processor executes the method in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer execution instructions, and the computer execution instructions are executed by the processor to implement the method in any one of claims 1 to 7.

11. A steer-by-wire system characterized by, comprising: a controller, a magnetorheological damper and a permanent magnet motor, the output shafts of the magnetorheological damper and the permanent magnet motor being connected in series and connected with the steering wheel, the magnetorheological damper and the permanent magnet motor being used to output feedback torque; the controller is used to execute the method in any one of claims 1 to 7.

12. A vehicle characterized by comprising: The vehicle comprises the steer-by-wire system in claim 11. The vehicle comprises the steer-by-wire system in claim 11.

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