Steer-by-wire cooperative control method, steering system and vehicle

Abstract

The invention provides a steer-by-wire cooperative control method, a steering system and a vehicle, which are applied to the technical field of steering control, and the control method comprises the following steps: obtaining a steering wheel hand torque, a steering wheel current angle position and a whole vehicle driving parameter; the target steering torque of a steering motor is calculated by taking the steering wheel hand torque as basic input and combining with the whole vehicle driving parameters; controlling a steering motor to act by using the target steering torque and outputting a response steering torque; acquiring a real-time rotor angle position of the steering motor and converting the real-time rotor angle position into a theoretical angle position of the steering wheel; according to the control method, the theoretical angle position of the steering wheel serves as a control target to control a road sensing motor to act and output response feedback torque, and the current angle position of the steering wheel is corrected so as to achieve global closed-loop control over vehicle steering. The steering system and the vehicle have the advantages of being stable and reliable in the power-assisted steering process.

Description

Technical Field

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

[0002] With the development of electric and intelligent vehicles, steer-by-wire has become an inevitable direction for the development of automotive chassis technology. In the research and development of steer-by-wire, the coordinated control of the steering actuator and the road feedback system is the most core technology.

[0003] The current collaborative control technology solution in the industry is to use an angle sensor to measure the steering wheel angle in real time. The steering actuator calculates the corresponding actuator target position based on the current steering wheel angle, and performs angle closed-loop control on the steering actuator servo motor. The actuator is driven by the servo motor to respond to the steering wheel angle input. At the same time, the steering actuator controller calculates the road reaction force estimate on the steering actuator based on the current steering actuator motor output torque, actuator position, speed, acceleration and system dynamics characteristics. The road feel feedback system controller controls the road feel motor output response torque based on the road reaction force estimate, simulating the road feel force feedback to the driver.

[0004] The advantages of such a technical solution are that it is easy to implement, simple to perform servo control, and suitable for modification and application based on the existing mechanical structure of the electric power steering system. However, the disadvantages of this solution are also very obvious, that is, it is difficult to further improve its performance and reliability to meet the requirements of industrialization. There are two main problems. First, since the steering mechanism of the whole vehicle is subjected to a large load from the road, and there are a large number of random vibrations, impacts and other inputs, the actuator needs to perform real-time follow-up control of the steering wheel angle under harsh variable load conditions, so the responsiveness is poor, resulting in a relatively large phase difference between the steering actuator and the steering wheel input. Secondly, the target signal of the road feel feedback is an estimate rather than a real measurement, and the dynamic model of the road to the steering actuator load calculated based on the driving servo motor current and the mechanism motion parameters is not well matched to the actual fitting effect, and the parameters based on the estimation are greatly affected by various factors such as ambient temperature and humidity, real-time working conditions, and the consistency cannot be guaranteed, resulting in the road feel feedback obtained by the driver not matching the actual vehicle dynamics and the steering feel is very poor. Summary of the invention

[0005] In view of this, the embodiments of the present specification provide a wire-controlled steering cooperative control method, a steering system and a vehicle. The use of this steering cooperative control method can not only eliminate the phase difference between the steering actuator and the steering wheel input shaft, but also make the road feel feedback more accurate and comfortable. The steering system and vehicle using this control method have a smooth and reliable steering assist process, while allowing the driver to obtain real road feel feedback and optimize the steering feel.

[0006] The embodiments of this specification first provide a coordinated control method for wire-controlled steering, including the following steps: obtaining the steering wheel hand torque, the current steering wheel angle position and the whole vehicle driving parameters; using the steering wheel hand torque as the basic input and combining the whole vehicle driving parameters to calculate the target steering torque of the steering motor; using the target steering torque to control the actuation of the steering motor and output a response steering torque; obtaining the real-time rotor angle position of the steering motor and converting it into a theoretical steering wheel angle position; using the theoretical steering wheel angle position as the control target to control the actuation of the road sense motor and output a response feedback torque, and correcting the current steering wheel angle position to achieve global closed-loop control of the vehicle steering.

[0007] In order to optimize the above scheme, the following technical measures are also taken: As a preferred implementation manner, the controlling the steering motor by using the target steering torque specifically comprises performing torque closed-loop control on the steering motor by using the target steering torque and the actual response steering torque.

[0008] As a preferred implementation manner, the controlling the road sense motor using the steering wheel theoretical angle position as the control target is specifically to perform angle closed-loop control on the road sense motor using the steering wheel input shaft angle corresponding to the steering wheel theoretical angle position as the target angle.

[0009] As a preferred implementation, the vehicle driving parameters include the current vehicle speed and the target steering angle of the vehicle.

[0010] As a preferred implementation, the real-time rotor angle position of the steering motor is obtained and converted into a theoretical steering wheel angle, specifically comprising: converting the real-time rotor angle position into an actual position of a steering actuator and calculating a corresponding real-time theoretical steering wheel angle according to a vehicle definition and a driving mode, wherein the vehicle definition includes parameter definitions of a vehicle steering ratio, a steering force and a steering gradient.

[0011] The embodiments of the present specification also provide a wire-controlled steering system for implementing the above-mentioned wire-controlled steering coordinated control method, the steering system comprising: a steering wheel unit, comprising a steering wheel, a first acquisition module for acquiring the steering wheel torque and the steering wheel angle position, and a steering wheel actuation mechanism for adjusting the steering wheel angle position; a road sense feedback unit, comprising a road sense motor coupled to the steering wheel actuation mechanism and a road sense feedback control module for calculating the theoretical angle position of the steering wheel and using this as a control target to control the road sense motor to output feedback torque; and a steering execution unit, comprising a steering actuator, a steering motor mechanically connected to the steering actuator, a second acquisition module for acquiring the steering motor rotor angle position, and a steering execution control module for calculating the target steering torque of the steering motor and using this to control the steering motor to output a response steering torque.

[0012] In order to optimize the scheme, the following technical measures are also taken: As a preferred embodiment, the steering wheel actuation mechanism includes a steering wheel input shaft, which is transmission-connected to the output shaft of the road sense motor through a worm gear structure, wherein the worm gear structure adopts a self-locking worm gear structure and the steering wheel input shaft serves as a worm gear shaft and the output shaft of the road sense motor serves as a worm gear shaft.

[0013] As a preferred embodiment, the steering wheel actuating mechanism also includes an intermediate speed-increasing transmission mechanism arranged on the steering wheel input shaft, and the intermediate speed-increasing transmission mechanism is located between the steering wheel and the worm gear structure. In particular, the intermediate speed-increasing transmission mechanism is, for example, a cylindrical gear transmission structure or a belt transmission structure.

[0014] As a preferred implementation, the first acquisition module is arranged on the steering wheel input shaft.

[0015] The embodiments of the present specification also provide a vehicle, comprising the above-mentioned steer-by-wire system.

[0016] Compared with the prior art, the at least one technical solution adopted in the embodiments of this specification can achieve the following beneficial effects: First, by adopting this control method, a global closed loop of the system consisting of driver-steering execution path-road sense feedback path-driver can be formed. Specifically, the driver first inputs hand torque to the steering wheel, and the target steering torque is calculated by combining the hand torque with the obtained vehicle driving parameters and the motor is controlled to output the response steering torque. Then the rotor angle position of the steering motor is obtained. Since the rotor of the steering motor is mechanically connected to the steering actuator, the measured rotor angle position can be converted into the actual position of the steering actuator. Then the theoretical angle position of the steering wheel is calculated from the actual position of the steering actuator and the road sense motor is controlled to output the response feedback torque based on this. The feedback torque corrects the current position of the steering wheel to match the theoretical position. At this time, the driver's hand torque is a disturbance, that is, the angle position of the steering wheel is controlled to match the actual position of the steering actuator with the idea of ​​reverse control, thereby bridging or even eliminating the phase difference between the steering wheel input shaft and the steering actuator.

[0017] Secondly, since a global closed-loop control or constraint is formed, the target steering torque and response steering torque calculated in the steering execution control process can be based on actual measurement rather than estimation, so that the consistency of the steering control data can be guaranteed, so that the road feel feedback obtained by the driver matches the actual vehicle dynamics, further optimizing the steering feel.

[0018] Furthermore, from the driver's perspective, the feedback mechanism from the application of force, that is, the steering action, to the output of the steering wheel movement that perceives the force application object is more in line with human behavioral cognition, and therefore can obtain a more expected control feel and a realistic feel. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a schematic diagram of the process of Example 1 in this application; Figure 2 This is a schematic diagram of module connection of a steering system in Example 1 of the present application; Figure 3 It is a schematic diagram of the architecture and interfaces of the control part in the steering system of Example 1 of the present application; Figure 4 It is a schematic diagram of the component structure of the steering system in Example 2 of the present application; Figure 5 It is a schematic diagram of the component structure of the steering system in Example 3 of the present application. DETAILED DESCRIPTION

[0021] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0022] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0023] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0024] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0025] The embodiments of this specification first propose a coordinated control method for wire-controlled steering, which aims to solve the problems in the prior art that there is a relatively large phase difference between the steering actuator and the steering wheel and the target signal of the road feel feedback is an estimate rather than an actual measurement, so that the consistency of the data relied on in the steering control process cannot be guaranteed, resulting in the road feel feedback obtained by the driver not matching the actual vehicle dynamics. It can not only eliminate the phase difference between the steering actuator and the steering wheel, but also establish a global closed-loop control including the steering execution control process and the road feel feedback control process, so that the steering assist is more accurate and the road feel feedback is more real and reliable. Example

[0026] like Figure 1 As shown, the embodiment of this specification first provides a wire-controlled steering collaborative control method, including the following steps: S101, obtaining the steering wheel hand torque, the current steering wheel angle position and the whole vehicle driving parameters, wherein the whole vehicle driving parameters include parameters such as the current vehicle speed and the target steering angle of the vehicle; S102, using the steering wheel hand torque as the basic input and combining the whole vehicle driving parameters to calculate the target steering torque of the steering motor; S103, using the target steering torque to control the actuation of the steering motor and output a response steering torque; S104, obtaining the real-time rotor angle position of the steering motor and converting it into the theoretical angle position of the steering wheel; S105, using the theoretical angle position of the steering wheel as the control target to control the actuation of the road sense motor and output a response feedback torque, and correcting the current angle position of the steering wheel to achieve global closed-loop control of the vehicle steering.

[0027] In this embodiment, the control method is applied to form a system global closed loop consisting of driver → steering execution path → road sense feedback path → driver. Specifically, the driver first inputs hand torque to the steering wheel, and the target steering torque is calculated by combining the hand torque with the obtained vehicle driving parameters, and the motor is controlled to output the response steering torque. Then, the rotor angle position of the steering motor is obtained. Since the rotor of the steering motor is rigidly connected to the driving wheel of the steering actuator, such as the driving gear or the driving pulley, through a mechanical mechanism, the measured rotor angle position can be converted into the actual position of the steering actuator. Then, the theoretical angle position of the steering wheel is calculated from the actual position of the steering actuator and the road sense motor is controlled to output the response feedback torque based on this. The feedback torque corrects the current angle position of the steering wheel to match the calculated theoretical position of the steering wheel. At this time, the driver's hand torque is a disturbance, that is, this embodiment controls the angle position of the steering wheel to match the actual position of the steering actuator based on the idea of ​​reverse control, thereby bridging or even eliminating the phase difference between the steering wheel and the steering actuator.

[0028] It should be emphasized that the core of this collaborative control method is to form a global closed-loop control. Different from the solution in the prior art that controls the steering motor and the steering actuator to follow and match the steering wheel angle position, the key to forming a global closed-loop control is to control the steering wheel angle position to follow and match the actual position of the steering actuator through the reverse control process. This not only eliminates the phase difference between the steering wheel and the steering actuator, but also ensures that the steering control data on the global closed-loop path are based on actual measurements rather than estimates, so that consistency can be guaranteed, thereby enabling the steering system to provide more accurate steering assistance and more realistic road feel feedback.

[0029] Specifically, in the above S103, the control of the steering motor using the target steering torque is specifically to use the target steering torque and the actual response steering torque to perform torque closed-loop control or semi-closed-loop control on the steering motor. Through this local torque closed-loop or semi-closed-loop control loop, a feedback mechanism is introduced to timely monitor and adjust the response steering torque of the steering motor, so that the output response steering torque is more accurate and reliable.

[0030] Specifically, in the above S105, the control of the road sense motor using the theoretical angle position of the steering wheel as the control target is to use the angle of the steering wheel input shaft corresponding to the theoretical angle position of the steering wheel as the target angle to perform angle closed-loop control on the road sense motor. Through this local angle closed-loop control loop, a feedback mechanism is introduced to timely monitor and adjust the response feedback torque of the road sense motor, so that the output response feedback torque is more accurate and reliable.

[0031] In the above S104, the real-time rotor angle position of the steering motor is obtained and converted into a theoretical steering wheel angle, specifically including: converting the real-time rotor angle position into an actual position of the steering actuator and calculating the corresponding real-time theoretical steering wheel angle according to the vehicle definition and driving mode, wherein the vehicle definition includes parameter definitions of vehicle steering ratio, steering force and steering gradient.

[0032] like Figures 2 to 3 As shown, this embodiment also provides a wire-controlled steering system for implementing the above-mentioned wire-controlled steering coordinated control method. The steering system includes: a steering wheel unit, a road sense feedback unit and a steering execution unit 101, wherein Figure 3 The road sense feedback unit and the steering wheel 100 are shown. The steering wheel unit includes a steering wheel, a first acquisition module for acquiring the steering wheel torque and the steering wheel angle position. and a steering wheel actuating mechanism for adjusting the steering wheel angle position, wherein the first acquisition module described herein adopts an angle / torque integrated sensor (TAS), a road sense feedback unit comprises a road sense motor coupled to the steering wheel actuating mechanism and a road sense feedback control module for calculating the theoretical angle position of the steering wheel and using it as a control target to control the output feedback torque of the road sense motor, a steering execution unit comprises a steering actuator, a steering motor mechanically connected to the steering actuator, a second acquisition module for acquiring the rotor angle position of the steering motor and a steering execution control module for calculating the target steering torque of the steering motor and using it to control the output steering torque of the steering motor, wherein the second acquisition module herein is a steering motor position sensor for detecting the rotor angle position of the steering motor.

[0033] like Figure 2 As shown, the torque closed-loop control circuit 11 is shown. Specifically, the steering execution unit 101 also includes a steering motor drive module, a current loop monitoring module and a bridge arm sampling resistor, wherein the bridge arm sampling resistor is used to sample the phase current output by the steering motor, and the current loop monitoring module is used to monitor the motor output state or generate a feedback signal according to the response torque for closed-loop control of the steering torque of the steering motor.

[0034] like Figure 2 As shown, the angle closed-loop control circuit 12 is shown. Specifically, the road sense feedback unit 101 also includes a road sense motor drive module, which is used to output phase current to control the actuation of the road sense motor. The TAS measures the actual steering wheel angle as a feedback signal to correct the target signal of the road sense motor.

[0035] Specifically, when the driver makes a steering action, a hand torque is output to the steering system. The first acquisition module measures the hand torque and outputs it in the form of a digital signal. The steering execution control module calculates the target steering torque that the steering motor needs to output in real time based on the hand torque and with reference to the current vehicle speed, the target steering angle of the vehicle and other vehicle driving parameters. The steering motor drive module controls the current of each phase according to the predetermined distribution output according to the steering torque. The steering motor outputs the response steering torque under the drive of the phase current. The current loop monitoring module of the steering motor calculates the actual output response steering torque of the motor based on the sampling signal of the bridge arm sampling resistor, and uses it as a reference signal to supply the motor drive module to monitor the motor output state or as a feedback signal to correct the real-time input target steering torque. The steering actuator responds to the driving of the steering torque and the external disturbance composed of road load, system friction, mechanism inertia and other elements. The steering wheel of the steering actuator is rigidly connected to the rotor shaft of the steering motor through a mechanical structure. Therefore, the second acquisition module, i.e., the rotor position sensor, outputs a rotor position signal. The road sense feedback control module can convert the real-time position of the steering actuator according to the signal, and calculate the corresponding real-time theoretical steering wheel angle position according to the vehicle definition such as steering ratio, steering force, steering gradient and driving mode. The road sense motor drive module uses the steering wheel input end angle corresponding to the steering wheel theoretical angle position as the target angle to output the phase current to control the actuation of the road sense motor. The road sense motor rotates to drive the steering wheel input shaft to move. At this time, the driver's hand torque is the disturbance acting on the steering wheel. The steering wheel rotates under the joint action of this disturbance and the road sense motor drive. The TAS measures the actual steering wheel angle as a feedback signal to correct the target signal of the road sense motor. Thus, a global closed-loop control loop 13 is formed between the driver, the steering wheel unit, the steering execution unit and the road feel feedback unit. Due to the formation of a global closed-loop control or constraint, the target steering torque and the response steering torque calculated by the steering execution control process can be based on actual measurement rather than estimation, so that the consistency of the steering control data can be guaranteed, so that the road feel feedback obtained by the driver matches the actual vehicle dynamics, further optimizing the steering feel. From the driver's perspective, the feedback mechanism from the application of force, i.e., the steering action, to the output of the perception of the force application object, i.e., the movement of the steering wheel, is more in line with human behavioral cognition, so a more expected control feel and real feel can be obtained.

[0036] This embodiment also provides a vehicle, comprising the above-mentioned steer-by-wire system. Figure 3The structure and interface of the control part of the steering system are shown. The double solid line, solid line and dotted line in the figure represent mechanical flow, electrical flow and signal flow respectively. Among them, the road sense feedback control module and the steering execution control module are both connected to the vehicle network bus 103 for communication. The vehicle power supply 104 supplies power to the road sense feedback unit and the steering execution unit. The TAS is mechanically connected to the steering wheel input shaft, and the steering wheel input shaft is connected to the output shaft of the road sense motor. The input torque (hand torque or the superposition value of hand torque and feedback torque) measured by the TAS is sent to the steering execution control module through the road sense feedback control module, and the steering execution control module controls the output phase current of the steering motor drive module to control the actuation of the steering motor, and then drives the actuation of the steering actuator, and the steering actuator drives the chassis of the vehicle to move, thereby realizing the steering control of the vehicle. The steering wheel angle measured by the TAS is sent to the road sense feedback control module, and the road sense feedback control module controls the output phase current of the road sense motor drive module to control the actuation of the road sense motor, and then outputs the feedback torque. Example

[0037] refer to Figure 4 As shown in the figure, in the prior art, the road sense feedback unit based on the traditional electric power steering system cannot maintain the phase constraint between the steering wheel and the steering actuator when the road sense motor has no output. In actual applications, it is very common for the steering wheel to be rotated by external force when the vehicle is powered off. Once this happens, the phase between the steering wheel and the steering actuator will not match, resulting in functional safety issues.

[0038] In order to overcome the problem that the steering wheel and the steering actuator cannot maintain phase after the power is turned off in the existing wire control steering system, this embodiment further improves the following steering wheel actuation mechanism part, such as Figure 4 As shown, the steering wheel actuation mechanism includes a steering wheel input shaft, which is connected to the output shaft of the road sense motor 2 through a worm gear structure 5, wherein the worm gear structure 5 adopts a self-locking worm gear structure and the steering wheel input shaft serves as a worm gear shaft and the output shaft of the road sense motor serves as a worm gear shaft.

[0039] Specifically, the first acquisition module, namely the angle / torque integrated sensor (TAS), is arranged on the steering wheel input shaft. The road sense motor 2 is provided with a road sense feedback control module 1, the output shaft of the road sense motor 2 is connected to the worm shaft through a coupling, the worm shaft and the worm shaft at the bottom of the steering wheel input shaft are connected through a self-locking worm gear structure, the top of the steering wheel input shaft is provided with a steering wheel assembly 9, and the bottom of the steering wheel assembly 9 is provided with a clock spring, a turn signal lamp, and a wiper lever assembly 8.

[0040] In the above control logic of reverse transmission, the external force applied by the driver to the steering wheel is only an interference term in the local road feel feedback closed-loop control, and due to the self-locking effect of the worm gear, the efficiency of reverse transmission is almost zero. Therefore, this interference cannot directly change the steering wheel angle output, thereby ensuring the stability of angle control.

[0041] It should be emphasized that if the road feel feedback unit adopts the method of correcting the steering wheel torque, it is not suitable for the solution of this embodiment. On the one hand, only correcting the input torque may still cause phase mismatch between the steering wheel and the steering actuator after power is turned off, resulting in that although the above-mentioned steering wheel actuator achieves reverse self-locking, the correct phase match between the steering wheel and the steering actuator is not achieved. On the other hand, even if the torque on the steering wheel remains unchanged, there is still a situation where the steering wheel rotates, such as when the vehicle is subjected to a large vibration load, so that the steering wheel and the actuator cannot maintain phase constraint. Example

[0042] like Figure 5 As shown, the contents of this embodiment are basically the same as those of the second embodiment, and the difference between the two is that the steering wheel actuating mechanism also includes an intermediate speed-increasing transmission mechanism arranged on the steering wheel input shaft, and the intermediate speed-increasing transmission mechanism is located between the steering wheel assembly 9 and the worm gear structure 5.

[0043] Since the worm gear structure 5 needs to meet the requirement of reverse self-locking, it is generally designed to have a large transmission ratio. Therefore, for some models with a relatively large steering angle transmission ratio, an intermediate speed increasing mechanism 6 needs to be provided to increase the output speed to meet the maximum steering speed requirement. The intermediate speed increasing mechanism can adopt a transmission mechanism such as a gear set and a synchronous belt, and the transmission ratio is designed according to the steering performance definition of the whole vehicle.

[0044] In the above embodiment, since a global closed-loop control is formed between the steering wheel unit, the steering actuator unit, and the road feel feedback unit, not only can the phase difference between the steering wheel and the steering actuator be eliminated, but also the steering control data on the global closed-loop path can be based on actual measurement rather than estimation, so that consistency can be guaranteed, so that the steering system can provide more accurate steering assistance and more realistic road feel feedback. At the same time, since the control signals sent and received by the road feel feedback unit and the steering actuator unit are all actual measurements, it is ensured that the road feel feedback can restore the actual load on the steering system of the entire vehicle, so the steering feel can also be greatly optimized.

[0045] In this specification, the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the embodiments described later, the description is relatively simple, and the relevant parts can be referred to the partial description of the previous embodiments.

[0046] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A coordinated control method for steering by wire, characterized in that: The steps include: Obtain steering wheel hand torque, current steering wheel angle position and vehicle driving parameters; The target steering torque of the steering motor is calculated by taking the steering wheel torque as the basic input and combining the vehicle driving parameters; Using the target steering torque to control the actuation of the steering motor and output a response steering torque; Obtain the real-time rotor angle position of the steering motor and convert it into the theoretical angle position of the steering wheel; The theoretical angle position of the steering wheel is used as the control target to control the actuation of the road sensing motor and output a response feedback torque, and the current angle position of the steering wheel is corrected to achieve global closed-loop control of the vehicle steering.

2. The steer-by-wire coordinated control method according to claim 1, characterized in that: The controlling the steering motor by using the target steering torque specifically involves performing torque closed-loop control on the steering motor by using the target steering torque and the actual response steering torque.

3. The steer-by-wire coordinated control method according to claim 1, characterized in that: The controlling of the road sense motor by taking the theoretical angle position of the steering wheel as the control target is specifically to perform angle closed-loop control on the road sense motor by using the rotation angle of the steering wheel input shaft corresponding to the theoretical angle position of the steering wheel as the target rotation angle.

4. The steer-by-wire coordinated control method according to any one of claims 1 to 3, characterized in that: The vehicle driving parameters include the current vehicle speed and the target steering angle of the vehicle.

5. The steer-by-wire coordinated control method according to any one of claims 1 to 3, characterized in that: The method of obtaining the real-time rotor angle position of the steering motor and converting it into a theoretical steering wheel angle specifically includes: converting the real-time rotor angle position into an actual position of a steering actuator and calculating a corresponding real-time theoretical steering wheel angle according to a vehicle definition and a driving mode, wherein the vehicle definition includes parameter definitions of a vehicle steering ratio, a steering force and a steering gradient.

6. A steer-by-wire system, characterized in that: For implementing the coordinated control method of wire steering according to any one of claims 1 to 5, the steering system comprises: A steering wheel unit, comprising a steering wheel, a first acquisition module for acquiring the steering wheel torque and the steering wheel angular position, and a steering wheel actuating mechanism for adjusting the steering wheel angular position; A road sense feedback unit, comprising a road sense motor coupled to the steering wheel actuation mechanism and a road sense feedback control module for calculating a theoretical angular position of the steering wheel and using the calculated angular position as a control target to control an output feedback torque of the road sense motor; and The steering execution unit includes a steering actuator, a steering motor mechanically connected to the steering actuator, a second acquisition module for acquiring the angular position of the steering motor rotor, and a steering execution control module for calculating the target steering torque of the steering motor and controlling the steering motor to output a response steering torque.

7. The steer-by-wire system according to claim 6, characterized in that: The steering wheel actuation mechanism includes a steering wheel input shaft, which is transmission-connected to the output shaft of the road sense motor through a worm gear structure, wherein the worm gear structure adopts a self-locking worm gear structure, and the steering wheel input shaft serves as a worm gear shaft and the output shaft of the road sense motor serves as a worm gear shaft.

8. The steer-by-wire system according to claim 7, characterized in that: The steering wheel actuating mechanism further comprises an intermediate speed-increasing transmission mechanism arranged on the steering wheel input shaft, and the intermediate speed-increasing transmission mechanism is located between the steering wheel and the worm gear structure.

9. The steer-by-wire system according to claim 7, characterized in that: The first acquisition module is arranged on the steering wheel input shaft.

10. A vehicle, characterized in that: Comprising a steer-by-wire system as claimed in any one of claims 6 to 9.

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