Worm type steer-by-wire device

Abstract

The utility model discloses a worm type steer-by-wire device which comprises a moment road sense feedback device, a steering column comprises a spline shaft, and one end of the spline shaft is connected with a steering wheel. The torque feedback assembly comprises a first gear shaft, an angle torque sensor, a motor, a worm and a worm gear. The first gear shaft is connected with the spline shaft. The angle torque sensor is installed on one side of the first gear shaft. The worm gear is mounted on the first gear shaft; a worm matched with the worm gear is arranged at the output end of the motor. Detecting the torque and angle of the steering wheel through an angle torque sensor; according to the detected torque and angle, a feedback torque is simulated through a motor, a worm and a worm gear, and linear steering control can be realized through simulating and adjusting steering damping through the motor; mechanical decoupling between the steering wheel and the steering actuator is achieved, the steering hand feeling is improved, and personalized driving requirements can be met.

Description

Technical Field

[0001] The utility model relates to the technical field, and particularly relates to a worm-type steer-by-wire device. Background Art

[0002] Traditional steering devices include a steering column, an intermediate steering shaft, and a steering actuator. The steering wheel and the steering tie rod connected to the wheels are connected by mechanical components, and the steering process is basically carried out with a fixed steering angle transmission ratio. During the vehicle driving process, the feedback from the road surface and the tires will be transmitted to the steering wheel through the steering gear, the intermediate shaft, and the steering column.

[0003] With the development of automotive intelligence and autonomous driving functions, new requirements such as variable steering angle transmission ratio, adjustable steering feel, foldable steering wheel, and telescopic steering column are put forward for steering devices. Traditional steering devices can no longer meet the requirements of intelligent driving for steering devices.

[0004] There is a need to design a steering device that can achieve a linear or non-linear steering angle transmission ratio to meet personalized driving needs. The steer-by-wire device has broad market application prospects in automotive intelligence and autonomous driving. Summary of the Utility Model

[0005] Aiming at the above technical problems existing in the prior art, the utility model provides a worm-type steer-by-wire device, which realizes mechanical decoupling of the steering actuator through a torque road feel feedback component and simulates the steering road feel.

[0006] The utility model discloses a worm-type steer-by-wire device, including a torque road feel feedback device, the torque road feel feedback device includes a steering column and a torque feedback component installed on one side of the steering column, the steering column includes a spline shaft, and the outer end of the spline shaft is connected to the steering wheel; the torque feedback component includes a first gear shaft, an angle torque sensor, a motor, a worm, and a worm gear; the first gear shaft is connected to the inner end of the spline shaft, and the angle torque sensor is installed on one side of the first gear shaft; the worm gear is installed on the first gear shaft; the output end of the motor is provided with a worm that cooperates with the worm gear.

[0007] Preferably, one end of the housing of the torque feedback component is provided with a concave cavity, and the outer end of the first gear shaft is rotatably installed in the concave cavity;

[0008] A limit ring is rotatably installed in the concave cavity, and the inner teeth of the limit ring are meshed with the outer teeth of the first gear shaft;

[0009] One side of the limit ring is provided with a second limit boss;

[0010] A first limit boss that cooperates with the second limit boss is arranged in the concave cavity.

[0011] Preferably, an end cap is provided at the outer end of the concave cavity;

[0012] The spline shaft is connected to the steering wheel through the external spline at the outer end;

[0013] An upper bracket is provided on the housing, and the upper bracket is installed on the vehicle tube beam through the mounting holes.

[0014] Preferably, the side wall of the concave cavity is circular; the second limiting boss is installed on the side wall; the torque feedback assembly is detachably installed on one side of the steering column, and the housing of the steering column and the torque feedback assembly is an integral part; the spline shaft and the first gear shaft are an integral part.

[0015] Preferably, it further includes a controller assembly, and the controller assembly is respectively connected to the motor and the angle torque sensor; an input shaft is provided at the other end of the spline shaft, the inner hole of the input shaft is rigidly connected to one end of the torsion bar, and the other end of the torsion bar is rigidly connected to the inner hole of the first gear shaft;

[0016] The angle torque sensor includes a target plate and a body arranged at intervals,

[0017] The body is connected to the controller assembly through a wire harness.

[0018] Preferably, it further includes a steering actuator,

[0019] The steering actuator includes an electric drive controller, a drive motor, a ball screw nut pair and a steering tie rod,

[0020] The electric drive controller is respectively connected to the controller assembly and the drive motor;

[0021] The output end of the drive motor is connected to the nut of the ball screw nut pair, and the screw of the ball screw nut pair is connected to the steering tie rod.

[0022] Preferably, a rack is provided on the screw;

[0023] The external teeth on one side of the second gear shaft are engaged with the rack, and an angle sensor is arranged on the outside of the second gear shaft, and the angle sensor is connected to the electric drive controller.

[0024] Preferably, the output end of the drive motor is connected to the ball screw nut pair through a belt drive mechanism;

[0025] The angle sensor is connected to the electric drive controller through a sensing wire harness;

[0026] The controller assembly is connected to the electric drive controller through a CAN bus.

[0027] The present utility model also provides a control system for the above-mentioned worm-type steer-by-wire steering device, including a road feeling feedback module and a rack force merging module.

[0028] The road feeling feedback module is used to calculate the feedback torque of the steering wheel.

[0029] The rack force merging module is used to measure the position of the rack according to the angle feedback by the angle sensor, and calculate the rack force of the steering actuator.

[0030] The method for calculating the rack force includes: if the current vehicle speed is less than the first threshold, the rack force adopts the estimated rack force.

[0031] If the current vehicle speed exceeds the first threshold, the rack force is calculated through the vehicle model.

[0032] Preferably, the control system further includes an end limit module.

[0033] The end limit module is used to: calculate the target angle of the steering actuator and the rack end protection position according to the steering reference position, vehicle speed, steering wheel angle, steering wheel rotation speed and steering line angle ratio; when the position of the current rack reaches the rack end protection position, increase the feedback torque of the steering wheel and reduce the power assistance.

[0034] Preferably, the control system further includes any one of the following modules or their combinations: a damping torque module, an active return module, a hysteresis torque module, a rack force estimation module, a rack force estimation monitoring module, a position control monitoring module, a steering position control module, a torque control module and an operation mode management module.

[0035] The road feeling feedback module is used to obtain the rack force, steering wheel torque and current vehicle speed; according to the torque and current vehicle speed, obtain the feedback torque.

[0036] Specifically, the road feeling feedback module extracts the specific frequency of the rack force and adds the specific frequency to the final driving torque; according to different vehicle speeds and driver torques, adjusts the feedback torque in combination with the frequency; the feedback torque is determined by two-dimensional calibration data having a rack force dependence and a vehicle speed dependence.

[0037] The damping torque module is used to provide a damping torque through a damping torque function, and the damping torque function includes linear and quadratic damping controls, which are calculated by the steering wheel rotation speed and the vehicle speed respectively; then factorizes the output through the vehicle driving state to obtain oversteer or understeer conditions.

[0038] The active return module is used to: calculate an active return torque with reference to the vehicle speed and steering position, and generate an active rotation torque through speed closed-loop control to assist the steering wheel to actively return.

[0039] The hysteresis torque module is used to simulate the hysteresis torque, and the friction coefficient of the hysteresis torque is adjusted according to different vehicle speeds;

[0040] The rack force estimation module is used to calculate the estimated rack force of the steering actuator according to the rack position, the hand force on the steering wheel, and the torque of the drive motor;

[0041] The rack force estimation monitoring module is used to calculate the second rack force according to the estimated rack force, the state of the rack force estimation module, the rack moving speed, the hand force on the steering wheel, and the filtered drive motor torque, and calculate the error between the estimated rack force and the second rack force;

[0042] The position control monitoring module is used to monitor the position error between the target rack position and the actual rack position; if the position error exceeds the third threshold and the duration exceeds the fourth threshold, an error is reported, where the third threshold is adjustable and the fourth threshold can be adjusted according to the vehicle speed and the position error threshold;

[0043] The steering position control module uses the PID algorithm to convert the position control requirement into torque control and drives the rack position by monitoring the actual rack position, and can track the target rack position to achieve the position control goal;

[0044] The torque control module is used to calculate the motor torque demand value and the torque control state according to the driver's reference torque, the hand force on the steering wheel, the feedback torque of the steering wheel, the damping torque, the active return torque, the hysteresis torque, the reference torque, and the limit torque. By calculating the motor torque demand, the steering torque of the steering actuator can track the reference torque for torque drive, and at the same time monitor the error between the reference torque and the steering torque;

[0045] The operation mode management module is used for the conversion between different control modes, for checking the conversion conditions, and for managing the control modes required by ADAS. The control modes include steering alignment, handwheel grip, and manual steering.

[0046] Compared with the prior art, the beneficial effects of the present utility model are as follows: the torque and angle of the steering wheel are detected by the angle torque sensor; according to the detected torque and angle, the feedback torque is simulated through the motor, the worm, and the worm gear, and the steering damping can be simulated and adjusted by the motor to achieve linearized steering control; the mechanical decoupling between the steering wheel and the steering actuator is realized, the steering feel is improved, and the personalized driving requirements can be met. Brief Description of the Drawings

[0047] Figure 1 is a schematic structural diagram of the worm-type steer-by-wire device of the present utility model;

[0048] Figure 2 is a schematic structural diagram of the torque road feel feedback device

[0049] Figure 3 It is a sectional view of the torque feedback component;

[0050] Figure 4 It is a schematic installation diagram of the worm gear and the screw;

[0051] Figure 5 It is a schematic diagram of the transmission structure of the torque road feel feedback device;

[0052] Figure 6 It is a schematic diagram of the structure of the concave cavity;

[0053] Figure 7 It is a schematic diagram of the structure of the limit ring;

[0054] Figure 8 It is a logic block diagram of the worm - type steer - by - wire device;

[0055] Figure 9 It is a logic block diagram of the control system of the present utility model.

[0056] Markings in the figure: 1 torque road feel feedback device,

[0057] 11 steering column, 111 spline shaft, 112 external spline, 115 upper bracket, 116 mounting hole,

[0058] 12 torque feedback component, 121 housing, 122 end cover, 123 concave cavity, 125 first limit boss,

[0059] 13 input shaft, 14 torsion bar, 15 first gear shaft, 16 angle torque sensor, 161 wire harness, 162 body, 163 target plate, 17 limit ring, 171 second limit boss, 172 internal teeth, 18 controller assembly; 181 motor, 182 worm, 183 worm gear;

[0060] 2 steering wheel;

[0061] 3 steering actuator, 31 electric drive controller, 32 drive motor, 33 belt drive mechanism, 35 tie rod, 37 ball screw nut pair, 371 lead screw, 372 rack, 38 angle sensor, 381 sensing wire harness, 39 second gear shaft;

[0062] 51 rack force merging module, 52 road feel feedback module, 53 damping torque module, 54 active return - to - center module, 55 hysteresis torque module, 56 reference torque calculation module, 57 end limit module, 58 torque control module,

[0063] 61 rack force estimation module, 62 rack force estimation monitoring module, 63 position control monitoring module, 64 steering position control module. Detailed implementation manners

[0064] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts fall within the scope of protection of the present utility model.

[0065] The following further describes the present utility model in detail with reference to the accompanying drawings:

[0066] The present utility model provides a worm-type steer-by-wire device, as Figures 1-8 , including a torque feel feedback unit (TFU) 1. The torque feel feedback unit 1 includes a steering column 11 and a torque feedback assembly 12 mounted on one side of the steering column 11. The steering column 11 includes a spline shaft 111, and the outer end of the spline shaft 111 is connected to a steering wheel 2. The torque feedback assembly 12 includes a first gear shaft 15, an angle torque sensor 16, a motor 181, a worm 182 and a worm gear 183. The first gear shaft 15 is connected to the inner end of the spline shaft 111, and the angle torque sensor 16 is mounted on one side of the first gear shaft 15. The worm gear 183 is mounted on the first gear shaft 15. A worm 182 cooperating with the worm gear 183 is provided at the output end of the motor 181.

[0067] The torque and angle of the steering wheel 2 are detected by the angle torque sensor 16. According to the detected torque and angle, a feedback torque is simulated through the motor, the worm and the worm gear, and the steering damping can be simulated and adjusted by the motor to achieve linearized steering control. Mechanical decoupling between the steering wheel and the steering actuator 3 is realized, the steering feel is improved, and personalized driving requirements can be met. Moreover, impacts, vibrations, etc. from the road surface and the tires will not be transmitted to the steering wheel.

[0068] As Figures 3-7, one end of the housing 121 of the torque feedback assembly 12 is provided with a concave cavity 123, and the outer end of the first gear shaft 15 is rotatably installed in the concave cavity 123; the limit ring 17 is rotatably installed in the concave cavity 123, and the internal teeth 172 of the limit ring 17 are engaged with the external teeth of the first gear shaft 15; one side of the limit ring 17 is provided with a second limit boss 171; a first limit boss 125 matching with the second limit boss 171 is arranged in the concave cavity 123 for limiting the maximum rotation angle of the gear shaft 15 and the steering wheel. Angle limit is achieved through the external teeth of the first gear shaft, the internal teeth of the angle limit ring, and a set of limit bosses respectively arranged on the limit ring and the housing. Among them, the first gear shaft 15 and the internal gear of the limit ring 17 are eccentrically arranged. Different steering wheel 2 rotation turns can be achieved by setting the transmission ratio between the first gear shaft 15 and the internal gear of the angle limit ring 17. When the two limit bosses come into contact and limit, the rotation of the first gear shaft 15 is restricted. Similarly, when rotating in the opposite direction, the rotation angle of the steering wheel 2 is restricted.

[0069] As Figure 2 , an end cover 122 is arranged at the outer end of the concave cavity 123; the spline shaft 111 is connected with the steering wheel 2 through the external splines 112 at the outer end; an upper bracket 115 is arranged on the housing 121, and the upper bracket 115 is installed on the vehicle tube beam through the installation hole 116.

[0070] More specifically, the side wall of the concave cavity 123 is circular; the second limit boss 171 is installed on the side wall. The torque feedback assembly 12 is detachably installed on one side of the steering column 11; or the housing structures of the steering column and the torque feedback assembly are integrally formed. The spline shaft and the first gear shaft can also be integrally formed.

[0071] Figure 2 The controller assembly 18 is also shown, and the controller assembly 18 is respectively connected with the motor 181 and the angle torque sensor 16; the other end of the spline shaft 111 is provided with an input shaft 13, the inner hole of the input shaft 13 is rigidly connected with one end of the torsion bar 14, and the other end of the torsion bar 14 is rigidly connected with the inner hole of the first gear shaft 15; the angle torque sensor 16 includes a target plate 163 and a body 162 arranged at intervals, and the body 162 is connected with the controller assembly 18 through a wire harness 161.

[0072] The controller assembly controls the rotation of the motor to generate a resistance torque through a control algorithm. The torque output by the motor is transmitted to the first gear shaft through the worm and the worm gear. The first gear shaft transmits the resistance torque to the steering wheel 2 through the torsion bar, the input shaft and the spline shaft, realizing the torque road feeling feedback. The torque felt on the steering wheel 2 completely depends on the torque control of the torque feedback device.

[0073] Figure 1The steering actuator (FAA) 3 is shown, which includes an electric drive controller 31, a drive motor 32, a ball screw nut pair 37, and a steering tie rod 35. The electric drive controller 31 is respectively connected to the controller assembly 18 and the drive motor 32. The output end of the drive motor 32 is connected to the nut of the ball screw nut pair 37, and the screw 371 of the ball screw nut pair 37 is connected to the steering tie rod 35. The steering actuator 3 is connected to the controller assembly 18 through the CAN bus, realizing the mechanical decoupling of the steering actuator 3 from the torque road feel feedback device 1 and the steering wheel. The steering command is sent to the steering actuator 3 through the controller assembly 18.

[0074] A rack 372 is provided on the screw 371. The external teeth on one side of the second gear shaft 39 mesh with the rack 372. An angle sensor 38 is provided outside the second gear shaft 39, and the angle sensor 38 is connected to the electric drive controller 31. The detection value of the angle sensor 38 reflects the position and displacement of the rack, and is used to monitor the steering control result.

[0075] More specifically, the output end of the drive motor 32 is connected to the ball screw nut pair 37 through a belt drive mechanism 33. The angle sensor 38 is connected to the electric drive controller 31 through a sensing wire harness 381. The controller assembly 18 is connected to the electric drive controller 31 through the CAN bus. The CAN bus can adopt a private CAN. The electric drive controller and the controller assembly 18 can adopt corresponding microprocessors according to design requirements, such as adopting an ARM microprocessor, an STM32 microprocessor, etc., but not limited to this.

[0076] The present utility model also provides a control system for the above worm-type steer-by-wire device, as Figure 9 shown, the control system includes a road feel feedback module 52 and a rack force merging module 51.

[0077] The rack force merging module 51 is used to measure the position of the rack according to the angle fed back by the angle sensor 38 and calculate the rack force of the steering actuator 3 (referred to as the merged rack force). The method for calculating the rack force includes: if the current vehicle speed is less than the first threshold, the rack force adopts the estimated rack force; if the current vehicle speed exceeds the first threshold, the rack force is calculated through a vehicle model (Vehicle Model Rack Force).

[0078] The road feel feedback module 52 is used to calculate the feedback torque of the steering wheel. More specifically, according to the rack force, vehicle speed, and steering wheel hand force (steering wheel torque), and through an interpolation function, the feedback torque is calculated and controlled. The road feel feedback module can extract the specific frequency of the rack force and add the specific frequency to the final drive torque; the feedback torque is adjusted in combination with the frequency according to different vehicle speeds and driver torques.

[0079] The damping torque module 53 is used to provide a damping torque through a damping torque function, which includes linear and quadratic damping controls. The linear and quadratic damping controls are calculated respectively based on the steering wheel rotation speed and the vehicle speed; then, it is factorized through the vehicle driving state to output an oversteer or understeer condition.

[0080] The active return module 54 is used to: calculate an active return torque by referring to the vehicle speed and the steering position, and generate an active rotation torque through speed closed-loop control to assist the steering wheel to return actively. The active return module calculates the active rotation torque based on the following factors: vehicle speed, driving state, steering wheel rotation speed, steering wheel hand force, and steering wheel angle.

[0081] The hysteresis torque module 55 is used to simulate the hysteresis torque, and the friction coefficient of the hysteresis torque is adjusted according to different vehicle speeds. The hysteresis torque is calculated based on the following factors: rack force, steering wheel hand force, steering wheel angle, and steering wheel rotation speed.

[0082] The reference torque calculation module 56 is used to calculate a reference torque based on the combined rack force, vehicle speed, and driving state. Among them, the driving state is calculated by a vehicle dynamic function, and the considerations of the vehicle dynamic function are: vehicle speed, target angle, yaw rate, and lateral acceleration. The purpose is to give a basic steering reference torque based on the estimated rack force. The basic steering reference torque is determined by two-dimensional calibration data with a rack force dependence and a vehicle speed dependence.

[0083] The end limit module 57 is used to: calculate the target angle of the steering actuator and the rack end protection position according to the steering reference position (TFU RES position), vehicle speed, steering wheel angle, steering wheel rotation speed, and steering line angle ratio; when the current position of the rack reaches the rack end protection position, increase the feedback torque of the steering wheel (abbreviated as the limit torque) and reduce the power assist.

[0084] This module introduces the vehicle speed, steering wheel angle, and steering line angle ratio to calculate the target angle of the steering actuator and the rack end protection position of the torque road feel simulator. The target angle and the rack end protection position of the torque road feel simulator are affected by the steering position and the vehicle speed. At different vehicle speeds, different steering line angle ratios are set, and the corresponding steering wheel angles when the rack reaches the end protection are also different. When the rack reaches the rack end protection stroke, the torque road feel simulator increases the steering resistance torque, allowing the driver to perceive an increase in steering damping, avoiding excessive steering of the steering wheel, so as to achieve rack end protection. That is, at different vehicle speeds, the steering angles of the rack end protection of the torque road feel simulator are different.

[0085] Among them, the target angle and the end protection position are affected by the vehicle speed and the steering line angle ratio. The steering reference position is calculated by the steering reference position generation module based on the vehicle speed, the steering angle position, and the steering transmission ratio to calculate the axle target position (Axle Target Position), and calculate the target angle and the steering reference position (TFU RES position).

[0086] Based on the vehicle speed and the steering position, the rotational speed generates an additional reference torque, reducing the assistance when the steering actuator approaches the end to achieve the mechanical protection function of the rack.

[0087] The torque control module 58 is used to calculate the motor torque demand value and the torque control state according to the driver reference torque, the steering wheel hand force, the feedback torque of the steering wheel, the damping torque, the active rotation torque, the hysteresis torque, the reference torque, and the limit torque. By calculating the motor torque demand, the steering torque of the steering actuator can track the reference torque for torque drive, while monitoring the error between the reference torque and the steering torque.

[0088] The rack force estimation module 61 is used to calculate the estimated rack force of the steering actuator according to the rack position, the steering wheel hand force, and the driving motor torque.

[0089] The rack force estimation monitoring module 62 is used to calculate the second rack force according to the estimated rack force, the state of the rack force estimation module 61, the rack moving speed, the steering wheel hand force, and the filtered driving motor torque (torque), and calculate the error between the estimated rack force and the second rack force.

[0090] The position control monitoring module 63 is used to monitor the position error between the target rack position and the actual rack position; if the position error exceeds the third threshold and the duration exceeds the fourth threshold, an error is reported, where the third threshold is adjustable and the fourth threshold can be adjusted according to the vehicle speed and the position error threshold.

[0091] The steering position control module 64 uses the PID algorithm to convert the position control requirement into torque control, and drives the rack position by monitoring the actual rack position, and can track the target rack position to achieve the position control target.

[0092] The operation mode management module is used for the conversion between different control modes, for checking the conversion conditions, and for managing the control modes required by ADAS. The control modes include steering alignment, handwheel grip, and manual steering. Different steering feels can be provided for the driver according to different vehicle modes. When switching the driver mode, the steering wheel torque and the vehicle speed will be checked first, and then the current steering feel will be obtained through the interpolation function.

[0093] The present utility model cancels the steering intermediate shaft, realizes the mechanical decoupling of the upper steering column and the steering actuator, and is a steer-by-wire device that adds a torque feedback device to the steering column to simulate the road feel of steering. Since there is no mechanical connection between the steering wheel and the steering actuator, different or even non-linear steering angle transmission ratios can be achieved by using a control program to meet personalized driving needs. Through the torque feedback device connected to the steering wheel, the steering damping can be freely adjusted to achieve various advanced functions such as personalized steering feel.

[0094] Therefore, the steer-by-wire device of the present utility model has broad market application prospects in vehicle intelligence and vehicle autonomous driving. The structure of the present utility model is compact and reliable, has a high safety redundancy, an adjustable steering angle transmission ratio, and an adjustable steering feel, and can support a telescopic / folding steering wheel and a steer-by-wire device that supports a silent steering wheel.

[0095] The hand force, angle, and rotational speed signals of the steering wheel are detected by a torque angle sensor, and vehicle control signals, external torque or angle requests, as well as steering mode or status and measurement values are received through the vehicle CAN bus. The control unit calculates the feedback torque, executes the steering feel control, and outputs the angle request value for the steering actuator.

[0096] The torque road feel feedback device converts the driver's angle input into the steering wheel position requirement of the steering actuator. The torque road feel feedback device generates a simulated feedback torque to the driver's hand feel according to the rack force and rack position feedback by the steering actuator.

[0097] The rack position signal is detected by a steering angle sensor, and the angle request signal is received through the private CAN bus of the steer-by-wire system, and the vehicle external angle request signal and vehicle speed signal are received through the vehicle CAN bus. The control unit calculates the torque and executes the position control of the steering actuator. At the same time, the steering actuator feeds back the current status information to the torque road feel feedback device, including the measured rack position and the calculated rack force. The steering actuator pushes the steering wheel to the target position according to the defined performance, calculates the current rack force in real time, detects the rack position, and feeds back the current data and status to the torque road feel feedback device.

[0098] The above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. For those skilled in the art, the present utility model can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A worm-type wire-controlled steering device, characterized in that: The invention comprises a torque road sense feedback device (1), wherein the torque road sense feedback device (1) comprises a steering column (11) and a torque feedback component (12) installed on one side of the steering column (11). The steering column (11) comprises a spline shaft (111), and the outer end of the spline shaft (111) is connected to the steering wheel (2); The torque feedback assembly (12) comprises a first gear shaft (15), an angle torque sensor (16), a motor (181), a worm (182) and a worm wheel (183); The first gear shaft (15) is connected to the inner end of the spline shaft (111), and the angle torque sensor (16) is installed on one side of the first gear shaft (15); The worm gear (183) is mounted on the first gear shaft (15); The output end of the motor (181) is provided with a worm (182) that matches the worm wheel (183).

2. The worm-type steer-by-wire device according to claim 1, characterized in that: A concave cavity (123) is provided at one end of the housing (121) of the torque feedback assembly (12), and the outer end of the first gear shaft (15) is rotatably mounted in the concave cavity (123); A limiting ring (17) is rotatably mounted in the concave cavity (123), and the inner teeth (172) of the limiting ring (17) are meshed with the outer teeth of the first gear shaft (15); A second limiting boss (171) is provided on one side of the limiting ring (17); A first limiting boss (125) matching with the second limiting boss (171) is arranged in the concave cavity (123).

3. The worm-type steer-by-wire device according to claim 2, characterized in that: An end cover (122) is provided at the outer end of the concave cavity (123); The spline shaft (111) is connected to the steering wheel (2) via an external spline (112) at an outer end; An upper bracket (115) is provided on the housing (121), and the upper bracket (115) is mounted on the vehicle pipe beam through a mounting hole (116).

4. The worm-type steer-by-wire device according to claim 3, characterized in that: The side wall of the concave cavity (123) is circular; The second limiting boss (171) is installed on the side wall; The torque feedback component (12) is detachably mounted on one side of the steering column (11), or the steering column and the housing of the torque feedback component are an integrated part; The spline shaft and the first gear shaft are an integral piece.

5. The worm-type steer-by-wire device according to claim 1, characterized in that: It also includes a controller component (18), the controller component (18) being connected to the motor (181) and the angle torque sensor (16) respectively; an input shaft (13) is provided at the inner end of the spline shaft (111), the inner hole of the input shaft (13) is rigidly connected to one end of a torsion bar (14), and the other end of the torsion bar (14) is rigidly connected to the inner hole of the first gear shaft (15); The angle torque sensor (16) comprises a target plate (163) and a body (162) which are arranged at intervals. The body (162) is connected to the controller assembly (18) via a wiring harness (161).

6. The worm-type steer-by-wire device according to claim 5, characterized in that: Also includes a steering actuator (3), The steering actuator (3) comprises an electric drive controller (31), a drive motor (32), a ball screw nut pair (37) and a steering tie rod (35). The electric drive controller (31) is connected to the controller component (18) and the drive motor (32) respectively; The output end of the driving motor (32) is connected to the nut of the ball screw nut pair (37), and the lead screw (371) of the ball screw nut pair (37) is connected to the steering tie rod (35).

7. The worm-type steer-by-wire device according to claim 6, characterized in that: The lead screw (371) is provided with a rack (372); The external teeth on one side of the second gear shaft (39) mesh with the rack (372), and an angle sensor (38) is provided on the outer side of the second gear shaft (39), and the angle sensor (38) is connected to the electric drive controller (31).

8. The worm-type steer-by-wire device according to claim 7, characterized in that: The output end of the driving motor (32) is connected to the ball screw nut pair (37) via a belt transmission mechanism (33); The angle sensor (38) is connected to the electric drive controller (31) via a sensor harness (381); The controller component (18) is connected to the electric drive controller (31) via a CAN bus.

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