Unmanned electric steering wheel control system and electric steering wheel

Abstract

The invention discloses an unmanned electric steering wheel control system and an electric steering wheel, and relates to the technical field of automobile steering wheel control systems.The system comprises a data acquisition and preprocessing module, a feature extraction and decision conversion module, a control execution module, a communication module, a safety monitoring module and an automatic calibration module; according to the invention, on the data processing and decision-making level, the feature information highly related to the steering decision is accurately extracted through effective learning of a large amount of historical driving data by the deep learning feature extraction model, and is converted into the accurate steering decision indication according to the predefined communication protocol, so that the scientificity and accuracy of the steering decision are greatly improved, and the decision-making efficiency is improved. And complex and changeable road conditions can be effectively handled.

Description

Technical Field

[0001] The invention relates to the technical field of automobile steering wheel control systems, and in particular to an unmanned driving electric steering wheel control system and an electric steering wheel. Background Art

[0002] With the rapid development of automobile technology towards automation and intelligence, driverless vehicles have become a research hotspot and future development trend in the field of transportation. In the driverless system, the electric steering wheel control system plays a vital role, and its accuracy and reliability directly affect the driving safety and comfort of the vehicle.

[0003] In this regard, patent document publication number KR1019970026719A discloses an automatic steering system for driverless cars. The invention can accurately control the steering angle of the driverless car by using the global positioning system and map information, so that the car can automatically drive along a predetermined route, and can automatically adjust the steering angle in real time according to the driving environment. It can accurately control the steering angle of the driverless car by using GPS and map information, so that the car can automatically drive along a predetermined route, and can automatically adjust the steering angle in real time according to the driving environment, thereby improving the driving safety and driving efficiency of the driverless car.

[0004] However, the decision-making algorithm of the autonomous driving electric steering wheel needs to process a large amount of environmental information and vehicle status data to make accurate steering decisions. Due to the complexity and uncertainty of the road environment, the decision-making algorithm often faces huge computing pressure and challenges, which may lead to decision delays or errors.

[0005] In view of the above problems, an unmanned driving electric steering wheel control system and an electric steering wheel are proposed. Summary of the invention

[0006] The purpose of the present invention is to provide an unmanned driving electric steering wheel control system and an electric steering wheel, which solves the problem of inaccurate decision-making in the background technology.

[0007] To achieve the above object, the present invention provides the following technical solution: an unmanned electric steering wheel control system, comprising:

[0008] A data acquisition and preprocessing module, used to acquire raw data and perform cleaning and denoising on the raw data, wherein the raw data at least includes data of a steering angle sensor and a torque sensor;

[0009] A feature extraction and decision conversion module, for a feature extraction model and a predefined system communication protocol, wherein the feature extraction model collects historical driving data and converts it into a standardized steering decision instruction according to the predefined system communication protocol, wherein the steering decision instruction includes an accurate steering angle value, a torque value range, and a target vehicle speed setting;

[0010] A control execution module receives the decision instruction and drives the motor of the electric steering wheel to operate through a PID control method according to the decision instruction, so as to achieve precise control of the steering of the steering wheel;

[0011] A communication module supports CAN, serial port and PWM communication modes, and is used to realize data transmission between the data acquisition and preprocessing module, the feature extraction and decision conversion module and the control execution module, as well as data interaction with external devices;

[0012] Safety monitoring module, used to monitor the working status of system hardware in real time. When hardware failure is detected, it will send out a warning signal and control the vehicle emergency braking;

[0013] The automatic calibration module automatically calibrates the steering wheel when the system is turned on and stores the vehicle information for use next time the system is turned on, ensuring that the steering wheel is in an accurate initial state.

[0014] Preferably, the predefined system communication protocol adopts the CAN bus protocol. After the characteristic information is converted into a standardized steering decision indication, data is encapsulated according to the frame format of the CAN bus protocol, wherein the steering angle value occupies 16 data bits, the torque value range occupies 16 data bits, and the target vehicle speed setting occupies 16 data bits, and the data bit allocation method is optimized according to the system's accuracy requirements for each parameter and the data transmission frequency.

[0015] Preferably, the precise steering angle value is calculated by the following formula: Where θ is the steering angle, L is the center distance of the front wheels of the vehicle, and R is the expected turning radius of the vehicle. The expected turning radius is calculated by the vehicle dynamics model based on the curvature of the road ahead and the current speed of the vehicle. The vehicle dynamics model includes the vehicle mass, inertia, and the friction between the tire and the ground. The calculation formula is: Where F is the tire lateral force, m is the vehicle mass, and v is the vehicle speed.

[0016] Preferably, the torque value range is determined based on the steering assist characteristic curve of the vehicle, and the corresponding torque range is found on the characteristic curve according to the current vehicle speed and steering angle. The fitting formula of the characteristic curve is: T = a + bv + cθ + dv 2 +eθ 2+fvθ, where T is the steering torque, v is the vehicle speed, θ is the steering angle, and a, b, c, d, e, and f are fitting coefficients.

[0017] Preferably, the target speed setting is adjusted according to the road conditions ahead and traffic regulations. When a curve is detected on the road ahead, the target speed calculation formula is: Where V t is the target speed, R is the curve radius, g is the acceleration of gravity, μ is the friction coefficient between the tire and the ground, and α is the inclination angle of the curve; when a traffic light or other vehicle is detected ahead, the target speed is calculated based on the preset safety distance and the braking performance of the vehicle.

[0018] Preferably, the automatic calibration module includes a steering wheel position sensor module, a controller module, an electric adjustment mechanism module, a memory module, a vehicle information recognition module and a fault detection and diagnosis module.

[0019] Preferably, the steering wheel position sensor module adopts a Hall sensor array, which is evenly distributed around the rotating axis of the steering wheel. It generates multiple analog voltage signals by sensing the changes in magnetic field strength and direction when the steering wheel rotates, and transmits them to the controller module in the form of digital signals.

[0020] Preferably, the electric regulating mechanism monitors the motor driving current in real time, sets voltage monitoring points at the power input and output ends of the controller module respectively, detects the stability of the power supply voltage, and uses the check bit and heartbeat signal in the communication protocol to monitor the connection status of the communication lines between the modules.

[0021] An electric steering wheel for an unmanned electric steering wheel control system, the electric steering wheel comprising an electric adjustment mechanism, the electric adjustment mechanism consisting of a motor and a transmission assembly, the motor being connected to the transmission assembly, the transmission assembly being mechanically connected to the steering wheel to drive the steering wheel to adjust its position, a position sensor being installed on the electric adjustment mechanism, the position sensor collecting position information, a rotation angle and converting it into an electrical signal for transmission to a controller.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention provides an unmanned driving electric steering wheel control system and an electric steering wheel. First, at the data processing and decision-making level, a deep learning feature extraction model effectively learns a large amount of historical driving data, accurately extracts feature information that is highly relevant to steering decisions, and converts it into precise steering decision instructions based on a predefined communication protocol, which greatly improves the scientificity and accuracy of steering decisions and effectively responds to complex and changeable road conditions. Secondly, the PID control method adopted by the control execution module works closely with various parts of the system to achieve precise control of the steering wheel, enhance the stability and safety of vehicle driving, and further ensure the reliability and efficiency of unmanned driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a flow chart of the present invention;

[0025] Figure 2 It is a logical framework schematic diagram of the present invention;

[0026] Figure 3 It is a schematic diagram of the three-dimensional structure of the electric steering wheel of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings.

[0029] Combination Figure 1-Figure 3 , an unmanned driving electric steering wheel control system of the present invention comprises:

[0030] The data acquisition and preprocessing module is used to collect raw data and clean and denoise the raw data. The raw data includes at least the data of the steering angle sensor and the torque sensor. The steering force and angle adjustment strategies required at different vehicle speeds are different. Through the different steering angles, the sensor accurately records the real-time rotation angle of the steering wheel, providing the system with key feedback on the driver's manual operation intention or the execution of the steering command of the automatic driving system, thus achieving precise steering control. Secondly, the torque sensor can keenly sense the torque borne by the steering wheel, and infer the resistance during the steering process through the data of the friction change between the tire and the ground and the stress state of the mechanical components of the steering system, thereby assisting the system to optimize the steering power output and ensure the stability and smoothness of the steering operation;

[0031] The predefined system communication protocol adopts the CAN bus protocol. After converting the characteristic information into a standardized steering decision instruction, the data is encapsulated according to the frame format of the CAN bus protocol. The steering angle value occupies 16 data bits, the torque value range occupies 16 data bits, and the target speed setting occupies 16 data bits. The data bit allocation method is optimized according to the system's accuracy requirements for each parameter and the data transmission frequency.

[0032] The CAN bus protocol itself has a powerful error detection and processing mechanism, including cyclic redundancy check, bit filling, and error frame sending. During the data transmission process, each node calculates the CRC value when sending a data frame and attaches it to the CRC check field of the data frame. After receiving the data frame, the receiving node recalculates the CRC value and compares it with the received CRC value. If the two are inconsistent, it is determined that an error has occurred in the data transmission. At this time, the receiving node immediately sends an error frame to notify the sending node to resend the data to ensure the integrity and accuracy of the data. At the same time, the system also monitors the bus load rate in real time. When the bus load rate exceeds the preset threshold, the data transmission frequency is adjusted to avoid data transmission delays or losses caused by bus congestion.

[0033] The exact steering angle value is calculated using the following formula: Where θ is the steering angle, L is the center distance of the front wheels of the vehicle, and R is the expected turning radius of the vehicle. The expected turning radius is calculated by the vehicle dynamics model based on the curvature of the road ahead and the current speed of the vehicle. The vehicle dynamics model includes the vehicle mass, inertia, and the friction between the tire and the ground. The calculation formula is: Where F is the tire lateral force, m is the vehicle mass, and v is the vehicle speed;

[0034] The torque value range is determined based on the vehicle's steering assist characteristic curve. The corresponding torque range is found on the characteristic curve according to the current vehicle speed and steering angle. The fitting formula of the characteristic curve is: T = a + bv + cθ + dv 2 +eθ 2 +fvθ, where T is the steering torque, v is the vehicle speed, θ is the steering angle, and a, b, c, d, e, f are fitting coefficients;

[0035] The target speed setting is adjusted according to the road conditions and traffic rules ahead. When a curve is detected on the road ahead, the target speed calculation formula is: Where V t is the target speed, R is the curve radius, g is the acceleration of gravity, μ is the friction coefficient between the tire and the ground, and α is the inclination angle of the curve; when a traffic light or other vehicle is detected ahead, the target speed is calculated based on the preset safety distance and the braking performance of the vehicle.

[0036] The control execution module receives the decision instructions and drives the electric steering wheel motor to operate through PID control according to the decision instructions to achieve precise control of the steering of the steering wheel. The control execution module receives the decision instructions from the feature extraction and decision conversion module. These decision instructions contain precise steering angle values, torque value ranges and target vehicle speed setting information. At the same time, it maintains close communication with the data acquisition and preprocessing module to obtain the real-time measurement data of the vehicle speed sensor, steering angle sensor and torque sensor to calculate the error value e(k). At a certain moment, the decision instruction requires the steering wheel angle to reach 30°, and the steering angle sensor feedbacks that the current actual angle is 25°. The error at this time is e(k) = 30-25 = 5°. According to the sampling frequency of the sensor in the system and the system's requirements for real-time performance, determine the appropriate sampling period T. When the sampling frequency of the sensor is 100Hz, the sampling period T = 1 / 100 = 0.01s;

[0037] Communication module, which supports CAN, serial port and PWM communication modes, is used to realize data transmission between data acquisition and preprocessing module, feature extraction and decision conversion module and control execution module, as well as data interaction with external devices;

[0038] Safety monitoring module, used to monitor the working status of system hardware in real time. When hardware failure is detected, it will send out a warning signal and control the vehicle emergency braking;

[0039] The automatic calibration module automatically calibrates the steering wheel when the system is turned on, and stores the vehicle information for use next time the system is turned on, ensuring that the steering wheel is in an accurate initial state. The automatic calibration module includes a steering wheel position sensor module, a controller module, an electric adjustment mechanism module, a memory module, a vehicle information identification module and a fault detection and diagnosis module. The steering wheel position sensor module adopts a Hall sensor array, which is evenly distributed around the rotation axis of the steering wheel. By sensing the changes in magnetic field strength and direction when the steering wheel is turned, multiple analog voltage signals are generated. After amplification, filtering and analog-to-digital conversion by the signal conditioning circuit integrated in the sensor module, the signals are transmitted to the controller module in the form of digital signals. The digital signals can accurately reflect the position information of the steering wheel in three-dimensional space, including a rotation angle accuracy of ±0.1°, an up and down displacement accuracy of ±0.1mm, and a front and rear displacement accuracy of ±0.1mm. The signal conditioning circuit has an automatic calibration function, which can correct the zero drift and gain error of the sensor each time the vehicle is started, ensuring the accuracy and stability of the measurement data.

[0040] The fault detection and diagnosis module is implemented in the following ways: current sensors are connected to both ends of the motor winding of the electric adjustment mechanism to monitor the motor drive current in real time; voltage monitoring points are set at the power input and output ends of the controller to detect the stability of the power supply voltage; the check bit and heartbeat signal in the communication protocol are used to monitor the connection status of the communication lines between the modules; at the same time, a self-test circuit is built into the steering wheel position sensor module to periodically send a test pulse signal and detect its response; when any of the above monitoring parameters exceeds the preset normal range, the fault detection and diagnosis module immediately starts the fault classification processing procedure; for minor faults, such as temporary sensor signal abnormalities, online compensation and recovery are performed by sending correction instructions to the controller; for moderate faults, such as motor current overload or communication interruption, the electric adjustment mechanism is controlled to stop running, and detailed fault information and maintenance suggestions are displayed on the vehicle display; for serious faults, such as controller freeze or key hardware damage, in addition to executing the above measures, an emergency distress signal is sent to the remote monitoring center through the vehicle's emergency communication system, and the vehicle is automatically switched to a pure mechanical manual steering mode to ensure that the vehicle can drive to the nearest maintenance point in a safe state.

[0041] An electric steering wheel for an unmanned electric steering wheel control system, the electric steering wheel 1 comprises an electric adjustment mechanism, the electric adjustment mechanism is composed of a motor and a transmission assembly, the motor is connected to the transmission assembly, the transmission assembly is mechanically connected to the steering wheel to drive the steering wheel to adjust the position, a position sensor is installed on the electric adjustment mechanism, the position sensor collects position information, the rotation angle and converts it into an electrical signal and transmits it to a controller.

[0042] When the vehicle is turned on, the controller reads the standard position information in the memory chip, and compares and calculates it with the current position information fed back by the position sensor in real time, generates a control command based on the deviation value and sends it to the electric adjustment mechanism to drive the motor to automatically adjust the steering wheel to the standard position. The controller supports multiple sets of memory storage functions and can call the corresponding steering wheel position memory based on the user identification information of the vehicle. During the automatic correction process, the controller continuously receives feedback signals from the position sensor. Once an abnormal situation is detected, the operation of the electric adjustment mechanism is immediately stopped, and an alarm message is sent to the vehicle's human-computer interaction system. At the same time, the driver is allowed to manually intervene in the steering wheel position adjustment at any time, and the system automatically updates and stores the current manually adjusted position information as the new standard position.

[0043] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0044] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An unmanned electric steering wheel control system, characterized in that: include: A data acquisition and preprocessing module, used to acquire raw data and perform cleaning and denoising on the raw data, wherein the raw data at least includes data of a steering angle sensor and a torque sensor; A feature extraction and decision conversion module, for a feature extraction model and a predefined system communication protocol, wherein the feature extraction model collects historical driving data and converts it into a standardized steering decision instruction according to the predefined system communication protocol, wherein the steering decision instruction includes an accurate steering angle value, a torque value range, and a target vehicle speed setting; A control execution module receives the decision instruction and drives the motor of the electric steering wheel to operate through a PID control method according to the decision instruction, so as to achieve precise control of the steering of the steering wheel; A communication module supports CAN, serial port and PWM communication modes, and is used to realize data transmission between the data acquisition and preprocessing module, the feature extraction and decision conversion module and the control execution module, as well as data interaction with external devices; Safety monitoring module, used to monitor the working status of system hardware in real time. When hardware failure is detected, it will send out a warning signal and control the vehicle emergency braking; The automatic calibration module automatically calibrates the steering wheel when the system is turned on and stores the vehicle information for use next time the system is turned on, ensuring that the steering wheel is in an accurate initial state.

2. The unmanned driving electric steering wheel control system according to claim 1, characterized in that: The predefined system communication protocol adopts the CAN bus protocol. After converting the characteristic information into a standardized steering decision indication, data is encapsulated according to the frame format of the CAN bus protocol, wherein the steering angle value occupies 16 data bits, the torque value range occupies 16 data bits, and the target vehicle speed setting occupies 16 data bits, and the data bit allocation method is optimized according to the system's accuracy requirements for each parameter and the data transmission frequency.

3. The unmanned driving electric steering wheel control system according to claim 2, characterized in that: The precise steering angle value is calculated by the following formula: Where θ is the steering angle, L is the center distance of the front wheels of the vehicle, and R is the expected turning radius of the vehicle. The expected turning radius is calculated by the vehicle dynamics model based on the curvature of the road ahead and the current speed of the vehicle. The vehicle dynamics model includes the vehicle mass, inertia, and the friction between the tire and the ground. The calculation formula is: Where F is the tire lateral force, m is the vehicle mass, and v is the vehicle speed.

4. The unmanned driving electric steering wheel control system according to claim 3 is characterized in that: The torque value range is determined based on the vehicle's steering assist characteristic curve. The corresponding torque range is found on the characteristic curve according to the current vehicle speed and steering angle. The fitting formula of the characteristic curve is: T = a + bv + cθ + dv 2 +eθ 2 +fvθ, where T is the steering torque, v is the vehicle speed, θ is the steering angle, and a, b, c, d, e, and f are fitting coefficients.

5. The unmanned driving electric steering wheel control system according to claim 4, characterized in that: The target speed setting is adjusted according to the road conditions ahead and traffic rules. When a curve is detected on the road ahead, the target speed calculation formula is: Where V t is the target speed, R is the curve radius, g is the acceleration of gravity, μ is the friction coefficient between the tire and the ground, and α is the inclination angle of the curve; when a traffic light or other vehicle is detected ahead, the target speed is calculated based on the preset safety distance and the braking performance of the vehicle.

6. The unmanned driving electric steering wheel control system according to claim 1, characterized in that: The automatic calibration module includes a steering wheel position sensor module, a controller module, an electric adjustment mechanism module, a memory module, a vehicle information recognition module and a fault detection and diagnosis module.

7. The unmanned driving electric steering wheel control system according to claim 6, characterized in that: The steering wheel position sensor module adopts a Hall sensor array, which is evenly distributed around the rotation axis of the steering wheel. By sensing the changes in magnetic field strength and direction when the steering wheel rotates, multiple analog voltage signals are generated and transmitted to the controller module in the form of digital signals.

8. The unmanned driving electric steering wheel control system according to claim 7, characterized in that: The electric regulating mechanism monitors the motor driving current in real time, sets voltage monitoring points at the power input and output ends of the controller module respectively, detects the stability of the power supply voltage, and uses the check bit and heartbeat signal in the communication protocol to monitor the connection status of the communication lines between the modules.

9. The electric steering wheel of an unmanned driving electric steering wheel control system according to claims 1-8, characterized in that: The electric steering wheel (1) comprises an electric adjustment mechanism, which is composed of a motor and a transmission assembly. The motor is connected to the transmission assembly, and the transmission assembly is mechanically connected to the steering wheel to drive the steering wheel to adjust its position. A position sensor is installed on the electric adjustment mechanism, which collects position information, rotates the angle and converts it into an electrical signal and transmits it to a controller.

Images