Steering wheel limit position learning method, system, device and storage medium

Abstract

The application embodiment provides a steering wheel limit position learning method, system, device and storage medium. The method comprises the following steps: determining whether the steering wheel rotation angle meets the initialized rotation angle requirement according to the steering wheel rotation angle and the last steering wheel limit position; determining whether the current motor rotation speed meets the initialized rotation speed requirement according to the current motor rotation speed and the motor rotation speed corresponding to the last steering wheel limit position; determining whether the current motor torque meets the initialized torque requirement according to the current motor torque and the motor torque corresponding to the last steering wheel limit position; and taking the steering wheel rotation angle as the current steering wheel limit position when the steering wheel rotation angle meets the initialized rotation angle requirement, the current motor rotation speed meets the initialized rotation speed requirement and the current motor torque meets the initialized torque requirement. The method realizes autonomous learning of the steering wheel limit position and avoids the situation that the steering wheel rotation angle exceeds the steering wheel limit position without mechanical limiting.

Description

Technical Field

[0001] This invention relates to the field of automotive technology, and more particularly to a method, system, device, and storage medium for learning the extreme positions of a steering wheel. Background Technology

[0002] Mechanical hydraulic power steering systems, electro-hydraulic power steering systems, and electric power steering systems all belong to steering systems based on mechanical components. These mechanical systems optimize the force transmission characteristics of the steering system, providing assistance for steering control and improving the vehicle's handling stability and ride comfort. However, limited by their mechanical structure, they cannot change the angular transmission characteristics of the steering system, i.e., the vehicle's steering characteristics, thus making it difficult to achieve the active control required for autonomous driving.

[0003] Steer-by-wire technology eliminates the mechanical connection between the steering wheel and the steering wheels, completely freeing it from the limitations of mechanical components and using electrical energy to achieve steering. However, because of the elimination of mechanical connection components, the response speed of the steering actuator as the steering wheel turns will be delayed, especially during rapid steering; and when the steering wheel is turned to its extreme end, there is no mechanical limit, which may result in the steering wheel being turned beyond its limit. Summary of the Invention

[0004] This application provides a method, system, device, and storage medium for learning the steering wheel's extreme positions, which can autonomously learn the steering wheel's extreme positions and avoid situations where the steering wheel angle exceeds the steering wheel's extreme positions without mechanical limits.

[0005] According to a first aspect of this application, the present invention provides a steering wheel extreme position learning method, comprising:

[0006] Get the steering wheel angle, current motor speed, and current motor torque;

[0007] Based on the steering wheel angle and the previous steering wheel limit position, determine whether the steering wheel angle meets the initial angle requirements;

[0008] Based on the current motor speed and the motor speed at the corresponding previous steering wheel limit position, determine whether the current motor speed meets the initial speed requirements;

[0009] Based on the current motor torque and the motor torque at the corresponding previous steering wheel limit position, determine whether the current motor torque meets the initial torque requirements;

[0010] When the steering wheel angle meets the initial angle requirement, the current motor speed meets the initial speed requirement, and the current motor torque meets the initial torque requirement, the steering wheel angle is taken as the current steering wheel limit position.

[0011] According to an embodiment of the first aspect of this application, the method further includes:

[0012] Obtain the target angle of the steering gear and the steering wheel speed;

[0013] The torque required for angle following is determined based on the steering wheel angle, the target angle of the steering gear, and the steering wheel rotation speed.

[0014] When the required torque is within a preset torque range, the system determines whether the steering wheel angle meets the initial angle requirements based on the steering wheel angle and the previous steering wheel limit position.

[0015] According to an embodiment of the first aspect of this application, determining the torque required for angle following based on the steering wheel angle, the target angle of the steering gear, and the steering wheel rotation speed includes:

[0016] The steering gain speed is obtained by performing PID calculation based on the difference between the steering wheel angle and the target angle of the steering gear;

[0017] The steering following speed is calculated by superimposing the steering gain speed and the steering wheel speed.

[0018] The steering following speed is calculated using PID control to obtain the torque required for angle following.

[0019] According to an embodiment of the first aspect of this application, determining whether the steering wheel angle meets the initial steering wheel angle requirements based on the steering wheel angle and the previous steering wheel extreme position includes:

[0020] When the difference between the steering wheel angle and the previous steering wheel limit position meets the first preset range, a first steering angle flag value is obtained. The first steering angle flag value indicates that the steering wheel angle meets the initial steering angle requirements.

[0021] When the difference between the steering wheel angle and the previous steering wheel limit position does not meet the first preset range, a second steering angle flag value is obtained. The second steering angle flag value indicates that the steering wheel angle does not meet the initial steering angle requirements.

[0022] According to an embodiment of the first aspect of this application, determining whether the current motor speed meets the initial speed requirement based on the current motor speed and the motor speed at the corresponding previous steering wheel limit position includes:

[0023] When the difference between the current motor speed and the motor speed at the corresponding previous steering wheel limit position meets the second preset range, and the first steering angle flag value lasts for a first preset time, a first speed flag value is obtained. The first speed flag value indicates that the current motor speed meets the initial speed requirements.

[0024] When the difference between the current motor speed and the motor speed at the corresponding previous steering wheel limit position does not meet the second preset range, or the first steering angle flag value does not last for the first preset time, a second speed flag value is obtained. The second speed flag value indicates that the current motor speed does not meet the initial speed requirements.

[0025] According to an embodiment of the first aspect of this application, determining whether the current motor torque meets the initial torque requirement based on the current motor torque and the motor torque at the corresponding previous steering wheel limit position includes:

[0026] When the difference between the current motor torque and the motor torque at the corresponding previous steering wheel limit position is greater than a preset torque change coefficient, the current motor torque is greater than a preset torque value, and the first steering angle flag value lasts for a second preset time, a first torque flag value is obtained. The first torque flag value indicates that the current motor torque meets the initial torque requirements.

[0027] When the difference between the current motor torque and the motor torque at the corresponding previous steering wheel limit position is less than a preset torque change coefficient, the current motor torque is less than a preset torque value, or the first steering angle flag value has not lasted for a second preset time, a second torque flag value is obtained. The second torque flag value indicates that the current motor torque does not meet the initial torque requirements.

[0028] According to an embodiment of the first aspect of this application, the method further includes:

[0029] If the steering wheel angle does not meet the initial angle requirement, the current motor speed does not meet the initial speed requirement, or the current motor torque does not meet the initial torque requirement, the previous steering wheel limit position is taken as the current steering wheel limit position.

[0030] A second aspect of this application provides a steering wheel limit position learning device, comprising:

[0031] The input unit is used to obtain the steering wheel angle, current motor speed, and current motor torque.

[0032] The first judgment unit is used to determine whether the steering wheel angle meets the initial angle requirements based on the steering wheel angle and the previous steering wheel extreme position.

[0033] The second judgment unit is used to determine whether the current motor speed meets the initial speed requirements based on the current motor speed and the motor speed at the corresponding previous steering wheel limit position.

[0034] The third judgment unit is used to determine whether the current motor torque meets the initial torque requirements based on the current motor torque and the motor torque at the corresponding previous steering wheel limit position.

[0035] The current steering wheel limit position determination unit is used to determine the steering wheel angle as the current steering wheel limit position when the steering wheel angle meets the initial angle requirement, the current motor speed meets the initial speed requirement, and the current motor torque meets the initial torque requirement.

[0036] According to a third aspect of this application, an electronic device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steering wheel limit position learning method as described above.

[0037] According to a fourth aspect of this application, a computer storage medium stores computer-executable instructions for performing the steering wheel extreme position learning method as described above.

[0038] This application has the following beneficial effects: It determines whether the steering wheel angle meets the initial angle requirement based on the steering wheel angle and the previous steering wheel limit position; it determines whether the current motor speed meets the initial speed requirement based on the current motor speed and the motor speed at the corresponding previous steering wheel limit position; it determines whether the current motor torque meets the initial torque requirement based on the current motor torque and the motor torque at the corresponding previous steering wheel limit position; when the steering wheel angle meets the initial angle requirement, the current motor speed meets the initial speed requirement, and the current motor torque meets the initial torque requirement, the steering wheel angle is taken as the current steering wheel limit position; it achieves autonomous learning of the steering wheel limit position, avoiding situations where the steering wheel angle exceeds the steering wheel limit position without mechanical limits. Attached Figure Description

[0039] Figure 1 This is a flowchart illustrating the steps of the steering wheel extreme position learning method provided in an embodiment of this application;

[0040] Figure 2 This is a step diagram showing the steps to determine if the required torque is normal for angle following.

[0041] Figure 3 This is a sub-step diagram of step S200;

[0042] Figure 4This is a structural diagram of the steering wheel extreme position learning system provided in an embodiment of this application;

[0043] Figure 5 This is a structural diagram of the electronic device provided in the embodiments of this application. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0045] It should be noted that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, or the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0046] The embodiments of this application will be further described below with reference to the accompanying drawings.

[0047] An embodiment of this application provides a steering wheel limit position learning method, applied to a steer-by-wire system.

[0048] Steer-by-wire systems eliminate the mechanical connection between the steering wheel and the steering wheels, freeing them from the limitations of mechanical components. Steering is achieved using electrical energy, optimizing angular transmission characteristics. In a steer-by-wire system, the driver's actions are converted into electrical signals by sensors. These signals are then analyzed, processed, and transmitted directly to the actuators via wires.

[0049] The steer-by-wire system mainly consists of a steering wheel module, a main controller, an actuator module, a fault handling system, and a power supply. The steering wheel module, main controller, and actuator module are the three main components of the steer-by-wire system; the other modules are auxiliary.

[0050] The steering wheel module is the input module for steering intentions, including the steering wheel, angle sensor, torque sensor, return torque motor, and related accessories.

[0051] The steering wheel module measures the steering wheel's angle and torque, converts the driver's steering intention into a digital signal, and transmits it to the main controller. At the same time, the steering wheel module receives the torque signal fed back from the main controller and generates the steering wheel's return torque to provide the driver with corresponding road feel.

[0052] The main controller, or ECU, is the core of the steer-by-wire system, acting as its brain. It determines the control effect of the steer-by-wire system. Its main function is to analyze and process various signals, determine the steering intention and the vehicle's motion state, and output corresponding control commands.

[0053] The main controller analyzes and processes the collected signals, sending commands to the steering actuator motor and the return torque motor to ensure that the two motors work in coordination, thereby simulating the vehicle's steering motion and road feel. On the other hand, the main controller maintains real-time monitoring of the driver's actions and the vehicle's status, achieving intelligent control.

[0054] When the system detects unreasonable steering intentions, erroneous system commands, or vehicle instability, the main controller can promptly block the erroneous commands and automatically control the vehicle in an appropriate manner to restore it to a stable state as quickly as possible. Furthermore, when the steer-by-wire system malfunctions, the main controller can take timely remedial measures to ensure driving safety and stability.

[0055] The steering actuator module is responsible for realizing and executing the driver's steering intentions. It consists of a steering actuator motor, a steering motor controller, wheel steering components, and wheel angle sensors. The actuator module receives instructions from the main controller and, through the steering motor and its controller, controls the rotation of the steering wheels to achieve steering.

[0056] In addition, the wheel angle sensor synchronously feeds back the measured wheel position signal to the main controller for calculation, analysis, and closed-loop control.

[0057] The fault handling system is also an important module of the steer-by-wire system. It contains a series of monitoring and response procedures. When a malfunction occurs in the steer-by-wire system, the fault handling system takes corresponding measures according to the pre-set procedures to avoid or mitigate the harm caused by the malfunction and ensure the vehicle's driving safety to the greatest extent possible.

[0058] In addition, the power supply, as a power supply facility, is also an indispensable part of the steer-by-wire system.

[0059] The working principle of steer-by-wire is as follows: When the steering wheel is turned, the steering angle sensor and torque sensor convert the measured steering angle and torque information into electrical signals, which are then transmitted to the main controller. Simultaneously, the main controller receives wheel motion status signals collected by the corresponding sensors, such as vehicle speed, longitudinal acceleration, and yaw rate. Based on these signals, the main controller processes the steering wheel's steering angle and torque signals and sends control commands to the steering actuator motor to achieve appropriate steering. The main controller receives wheel information collected by the wheel angle sensors and, combined with the vehicle's status information, sends corresponding torque commands to the return torque motor. The return torque motor simulates road feedback information, providing the driver with real-time road feel. When the main controller malfunctions or fails, the fault handling module will take appropriate action based on the type and severity of the fault, ensuring the driver can detect the fault and maintain safe driving.

[0060] Reference Figure 1 The method for learning the extreme positions of the steering wheel includes, but is not limited to, the following steps:

[0061] Step S300: Obtain the steering wheel angle, current motor speed, and current motor torque;

[0062] Step S400: Based on the steering wheel angle and the previous steering wheel limit position, determine whether the steering wheel angle meets the initial angle requirements;

[0063] Step S500: Based on the current motor speed and the motor speed at the corresponding previous steering wheel limit position, determine whether the current motor speed meets the initial speed requirements.

[0064] Step S600: Based on the current motor torque and the motor torque at the corresponding previous steering wheel limit position, determine whether the current motor torque meets the initial torque requirements.

[0065] Step S700: When the steering wheel angle meets the initial angle requirement, the current motor speed meets the initial speed requirement, and the current motor torque meets the initial torque requirement, the steering wheel angle is taken as the current steering wheel limit position.

[0066] Steer-by-wire technology in automobiles eliminates the mechanical intermediate shaft, transmitting the driver's steering intentions via electrical signals and providing feedback on road conditions. The directness of steering, i.e., the response speed of the steering actuators as the steering wheel turns, has a very direct impact on the driver's experience, especially the significant steering delay during rapid turns.

[0067] Therefore, before adjusting the steering wheel to its limit, it is necessary to ensure that the angle follows the required torque correctly.

[0068] Reference Figure 2To determine if the angle is following the required torque correctly, the following steps are recommended:

[0069] Step S100: Obtain the steering wheel angle, the target angle of the steering gear, and the steering wheel speed;

[0070] Step S200: Determine the torque required for angle following based on the steering wheel angle, the target angle of the steering gear, and the steering wheel speed.

[0071] For step S100, the steering wheel angle and steering wheel speed are obtained by the sensor on the steering wheel, and the target angle of the steering gear is obtained by the sensor on the steering gear.

[0072] Reference Figure 3 For step S200, determining the torque required for angle following based on the steering wheel angle, the target angle of the steering gear, and the steering wheel speed includes:

[0073] Step S210: Perform PID calculation based on the difference between the steering wheel angle and the target angle of the steering gear to obtain the steering gain speed;

[0074] Step S220: The steering following speed is obtained by superimposing the steering gain speed and the steering wheel speed.

[0075] Step S230: Perform PID calculation on the steering following speed to obtain the torque required for angle following.

[0076] The steering wheel angle and the target angle of the steering gear are input to a subtractor for subtraction calculation. The subtractor outputs the difference between the steering wheel angle and the target angle of the steering gear. This difference is then input to a PID controller. The PID controller performs PID calculations based on this difference, multiplying it by a proportional coefficient, multiplying the integral value by an integral coefficient, and multiplying the derivative value by a differential coefficient. The sum of these three products yields the steering gain speed.

[0077] The steering gain speed and steering wheel speed are input into the speed superposition module for calculation to obtain the steering following speed.

[0078] The steering following speed is input into the PID controller. The PID controller performs PID calculations based on the steering following speed, multiplying the steering following speed by a proportional coefficient, multiplying the integral value of the steering following speed by an integral coefficient, and multiplying the derivative value of the steering following speed by a derivative coefficient. The three products are then added together to obtain the torque required for angle following.

[0079] The steering wheel limit position is adjusted only when the torque required for angle following meets the preset torque range; otherwise, the steering wheel limit position is not adjusted.

[0080] By subtracting the target angle of the steering gear from the steering wheel angle, a stable steering gain speed is output through a PID algorithm. Then, the steering wheel speed and the steering gain speed of the steer-by-wire actuator are superimposed to output the steering following speed. Finally, the steering following speed is processed by a PID algorithm to output the torque required for angle following, thus reducing the steering following delay of the steer-by-wire system.

[0081] For step S300, the current motor speed is obtained through the motor speed sensor. The input current to the motor is obtained through the motor current sensor. The input current is added to the current from another path to obtain the total motor current. The total motor current is divided by the rated current and multiplied by the rated motor torque to obtain the current motor torque.

[0082] The steering wheel can turn left or right; therefore, the steering wheel has left and right limit positions, and you need to learn both left and right limit positions.

[0083] The process of learning the extreme positions of the left-hand steering wheel is as follows.

[0084] When the steering wheel angle is less than 0, it is determined that the steering wheel is turning to the left.

[0085] For step S400, based on the steering wheel angle and the previous steering wheel limit position, it is determined whether the steering wheel angle meets the initial angle requirements, including:

[0086] When the difference between the steering wheel angle and the previous left steering wheel limit position meets the first preset range, the first steering angle flag value is obtained. The first steering angle flag value indicates that the steering wheel angle meets the initial steering angle requirements.

[0087] When the difference between the steering wheel angle and the previous left steering wheel limit position does not meet the first preset range, a second steering angle flag value is obtained. The second steering angle flag value indicates that the steering wheel angle does not meet the initial steering angle requirements.

[0088] The first turning point is represented by a value of 1, and the second turning point is represented by a value of 0.

[0089] Understandably, the first preset range can be set according to actual production needs; for example, the first preset range could be -3 degrees to 3 degrees. When the difference between the steering wheel angle and the previous left-hand steering wheel limit position meets the first preset range, it means that the steering wheel has been turned to near the previous left-hand steering wheel limit position.

[0090] For step S500, based on the current motor speed and the motor speed at the corresponding previous steering wheel limit position, it is determined whether the current motor speed meets the initial speed requirements, including:

[0091] When the difference between the current motor speed and the motor speed at the corresponding left steering wheel limit position meets the second preset range, and the first steering angle flag value lasts for the first preset time, the first speed flag value is obtained. The first speed flag value indicates that the current motor speed meets the initial speed requirements.

[0092] When the difference between the current motor speed and the motor speed at the corresponding left steering wheel limit position does not meet the second preset range, or the first steering angle flag value does not last for the first preset time, a second speed flag value is obtained. The second speed flag value indicates that the current motor speed does not meet the initial speed requirements.

[0093] Understandably, the second preset range can be set according to actual production needs. For example, the second preset range could be -100 rpm to 100 rpm. When the difference between the current motor speed and the motor speed at the corresponding previous left steering wheel limit position does not meet the second preset range, it indicates that the steering wheel has been turned to the vicinity of the previous left steering wheel limit position.

[0094] The first preset time can be set according to actual production needs. For example, the first preset time can be set to 0.1 seconds.

[0095] The first speed indicator value is represented by 1, and the second speed indicator value is represented by 0.

[0096] For step S600, based on the current motor torque and the motor torque at the corresponding previous steering wheel limit position, determine whether the current motor torque meets the initial torque requirements, including:

[0097] When the difference between the current motor torque and the motor torque at the corresponding left steering wheel limit position is greater than the preset torque change coefficient, the current motor torque is greater than the preset torque value, and the first steering angle flag value lasts for a second preset time, the first torque flag value is obtained. The first torque flag value indicates that the current motor torque meets the initial torque requirements.

[0098] When the difference between the current motor torque and the motor torque at the corresponding left steering wheel limit position is less than the preset torque change coefficient, the current motor torque is less than the preset torque value, or the first steering angle flag value has not lasted for the second preset time, a second torque flag value is obtained. The second torque flag value indicates that the current motor torque does not meet the initial torque requirements.

[0099] The difference between the current motor torque and the motor torque at the previous left-hand steering wheel limit position is the torque change rate.

[0100] Understandably, the torque variation coefficient can be set according to actual production needs. When the difference between the current motor torque and the motor torque at the previous left steering wheel limit position is less than the preset torque variation coefficient, it indicates that the steering wheel has been turned to the vicinity of the previous left steering wheel limit position.

[0101] The preset torque value can be set according to actual production needs. Specifically, the preset torque value is set to 1.

[0102] The second preset time can be set according to actual production needs. For example, the second preset time can be set to 0.1 seconds.

[0103] The first torque value is represented by 1, and the second speed value is represented by 0.

[0104] For step S700, the angle flag value, speed flag value, and torque flag value are input to the AND operator for AND operation.

[0105] When the steering wheel angle meets the initial angle requirement, the current motor speed meets the initial speed requirement, and the current motor torque meets the initial torque requirement, the input to the AND operator is the first angle flag value (1), the first speed flag value (1), and the first torque flag value (1), and the result of the AND operation is 1.

[0106] If the steering wheel angle does not meet the initial angle requirement, the current motor speed does not meet the initial speed requirement, or the current motor torque does not meet the initial torque requirement, input any one of the second angle flag value, the second speed flag value, and the second torque flag value with an existence value of 0 to the AND operator, and the result of the AND operation will be 0.

[0107] When the result of the AND operation is 1, it means that the extreme position of the left steering wheel needs to be initialized; when the result of the AND operation is 0, it means that the extreme position of the left steering wheel does not need to be initialized.

[0108] The output value of the AND operator, the steering wheel angle, and the previous left steering wheel limit position are input to the selector. The selector performs a selection operation on the steering wheel angle and the previous left steering wheel limit position based on the output value of the AND operator. When the output value of the AND operator is 1, the left steering wheel limit position needs to be initialized, and the steering wheel angle is selected as the current left steering wheel limit position. When the output value of the AND operator is 0, the left steering wheel limit position does not need to be initialized, the previous left steering wheel limit position is selected as the current left steering wheel limit position, and the left steering wheel limit position is maintained.

[0109] The process of learning the extreme positions of the right-hand steering wheel is as follows.

[0110] When the steering wheel angle is less than 0, it is determined that the steering wheel is turning to the left.

[0111] For step S400, based on the steering wheel angle and the previous steering wheel limit position, it is determined whether the steering wheel angle meets the initial angle requirements, including:

[0112] When the difference between the steering wheel angle and the previous right steering wheel limit position meets the first preset range, the first steering angle flag value is obtained. The first steering angle flag value indicates that the steering wheel angle meets the initial steering angle requirements.

[0113] When the difference between the steering wheel angle and the previous right steering wheel limit position does not meet the first preset range, a second steering angle flag value is obtained. The second steering angle flag value indicates that the steering wheel angle does not meet the initial steering angle requirements.

[0114] The first turning point is represented by a value of 1, and the second turning point is represented by a value of 0.

[0115] Understandably, the first preset range can be set according to actual production needs; for example, the first preset range could be -3 degrees to 3 degrees. When the difference between the steering wheel angle and the previous right steering wheel limit position meets the first preset range, it means that the steering wheel has been turned to near the previous right steering wheel limit position.

[0116] For step S500, based on the current motor speed and the motor speed at the corresponding previous steering wheel limit position, it is determined whether the current motor speed meets the initial speed requirements, including:

[0117] When the difference between the current motor speed and the motor speed at the corresponding right steering wheel limit position meets the second preset range, and the first steering angle flag value lasts for the first preset time, the first speed flag value is obtained. The first speed flag value indicates that the current motor speed meets the initial speed requirements.

[0118] When the difference between the current motor speed and the motor speed at the corresponding right steering wheel limit position does not meet the second preset range, or the first steering angle flag value does not last for the first preset time, a second speed flag value is obtained. The second speed flag value indicates that the current motor speed does not meet the initial speed requirements.

[0119] Understandably, the second preset range can be set according to actual production needs. For example, the second preset range could be -100 rpm to 100 rpm. When the difference between the current motor speed and the motor speed at the corresponding previous right steering wheel limit position does not meet the second preset range, it indicates that the steering wheel has been turned to the vicinity of the previous right steering wheel limit position.

[0120] The first preset time can be set according to actual production needs. For example, the first preset time can be set to 0.1 seconds.

[0121] The first speed indicator value is represented by 1, and the second speed indicator value is represented by 0.

[0122] For step S600, based on the current motor torque and the motor torque at the corresponding previous steering wheel limit position, determine whether the current motor torque meets the initial torque requirements, including:

[0123] When the difference between the current motor torque and the motor torque at the corresponding right steering wheel limit position is greater than the preset torque change coefficient, the current motor torque is greater than the preset torque value, and the first steering angle flag value lasts for a second preset time, the first torque flag value is obtained. The first torque flag value indicates that the current motor torque meets the initial torque requirements.

[0124] When the difference between the current motor torque and the motor torque at the corresponding right steering wheel limit position is less than the preset torque change coefficient, the current motor torque is less than the preset torque value, or the first steering angle flag value has not lasted for the second preset time, a second torque flag value is obtained. The second torque flag value indicates that the current motor torque does not meet the initial torque requirements.

[0125] The difference between the current motor torque and the motor torque at the corresponding extreme position of the right steering wheel is the torque change rate.

[0126] Understandably, the torque variation coefficient can be set according to actual production needs. When the difference between the current motor torque and the motor torque at the previous right steering wheel limit position is less than the preset torque variation coefficient, it indicates that the steering wheel has been turned to the vicinity of the previous right steering wheel limit position.

[0127] The preset torque value can be set according to actual production needs. Specifically, the preset torque value is set to 1.

[0128] The second preset time can be set according to actual production needs. For example, the second preset time can be set to 0.1 seconds.

[0129] The first torque value is represented by 1, and the second speed value is represented by 0.

[0130] For step S700, the angle flag value, speed flag value, and torque flag value are input to the AND operator for AND operation.

[0131] When the steering wheel angle meets the initial angle requirement, the current motor speed meets the initial speed requirement, and the current motor torque meets the initial torque requirement, the input to the AND operator is the first angle flag value (1), the first speed flag value (1), and the first torque flag value (1), and the result of the AND operation is 1.

[0132] If the steering wheel angle does not meet the initial angle requirement, the current motor speed does not meet the initial speed requirement, or the current motor torque does not meet the initial torque requirement, input any one of the second angle flag value, the second speed flag value, and the second torque flag value with an existence value of 0 to the AND operator, and the result of the AND operation will be 0.

[0133] When the result of the AND operation is 1, it means that the right steering wheel limit position needs to be initialized; when the result of the AND operation is 0, it means that the right steering wheel limit position does not need to be initialized.

[0134] The output value of the AND operator, the steering wheel angle, and the previous right steering wheel limit position are input to the selector. The selector performs a selection operation on the steering wheel angle and the previous right steering wheel limit position based on the output value of the AND operator. When the output value of the AND operator is 1, the right steering wheel limit position needs to be initialized, and the steering wheel angle is selected as the current right steering wheel limit position. When the output value of the AND operator is 0, the right steering wheel limit position does not need to be initialized, the previous right steering wheel limit position is selected as the current right steering wheel limit position, and the right steering wheel limit position is maintained.

[0135] It enables autonomous learning of the steering wheel's extreme positions, preventing the steering wheel from turning beyond its extreme position when there are no mechanical limits.

[0136] An embodiment of this application also provides a steering wheel extreme position learning system.

[0137] Reference Figure 4 The steering wheel extreme position learning system includes: an input unit 100, a first judgment unit 210, a second judgment unit 220, a third judgment unit 230, and a current steering wheel extreme position determination unit 300.

[0138] The input unit 100 is used to acquire the steering wheel angle, the current motor speed, and the current motor torque; the first judgment unit 210 is used to determine whether the steering wheel angle meets the initial angle requirement based on the steering wheel angle and the previous steering wheel limit position; the second judgment unit 220 is used to determine whether the current motor speed meets the initial speed requirement based on the current motor speed and the motor speed corresponding to the previous steering wheel limit position; the third judgment unit 230 is used to determine whether the current motor torque meets the initial torque requirement based on the current motor torque and the motor torque corresponding to the previous steering wheel limit position; and the current steering wheel limit position determination unit 300 is used to determine the steering wheel angle as the current steering wheel limit position when the steering wheel angle meets the initial angle requirement, the current motor speed meets the initial speed requirement, and the current motor torque meets the initial torque requirement.

[0139] It is understood that the steering wheel limit position learning system of this embodiment applies the steering wheel limit position learning method described above. Each unit of the steering wheel limit position learning system of this embodiment corresponds to each step of the steering wheel limit position learning method. The steering wheel limit position learning system of this embodiment has the same technical solution as the steering wheel limit position learning method, solves the same technical problems as the steering wheel limit position learning method, and has the same technical effects as the steering wheel limit position learning method.

[0140] An embodiment of this application provides an electronic device. (Refer to...) Figure 5 The electronic device includes: a memory 20, a processor 10, and a computer program stored on the memory 20 and executable on the processor 10. When the processor 10 executes the computer program, it implements the steering wheel limit position learning method as described above.

[0141] This electronic device can be any smart terminal, including computers.

[0142] In general, for the hardware structure of electronic devices, the processor 10 can be implemented using a general-purpose CPU (Central Processing Unit, microprocessor, Application Specific Integrated Circuit, ASIC), or one or more integrated circuits, to execute relevant programs and implement the technical solutions provided in the embodiments of this application.

[0143] The memory 20 can be implemented as a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 20 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program code is stored in the memory 20 and is called and executed by the processor 10.

[0144] Input / output interfaces are used to implement information input and output.

[0145] The communication interface is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0146] Bus 30 transmits information between various components of the device (e.g., processor 10, memory 20, input / output interface, and communication interface). Processor 10, memory 20, input / output interface, and communication interface are interconnected within the device via bus 30.

[0147] An embodiment of this application provides a computer storage medium. The computer storage medium stores computer-executable instructions for executing the steering wheel limit position learning method described above.

[0148] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, it is well known to those skilled in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium. In the foregoing description of this specification, references to terms such as "one embodiment," "another embodiment," or "some embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0149] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0150] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0151] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0152] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0153] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed between each other may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms. Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

[0154] The above is a detailed description of the preferred embodiments of this application, but this application is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A method for learning the extreme positions of a steering wheel, characterized in that, include: Get the steering wheel angle, current motor speed, and current motor torque; Obtain the target angle of the steering gear and the steering wheel speed; The torque required for angle following is determined based on the steering wheel angle, the target angle of the steering gear, and the steering wheel rotation speed. When the required torque is within a preset torque range, the steering wheel angle is determined to meet the initial angle requirements based on the steering wheel angle and the previous steering wheel limit position. Based on the current motor speed and the motor speed at the corresponding previous steering wheel limit position, determine whether the current motor speed meets the initial speed requirements; Based on the current motor torque and the motor torque at the corresponding previous steering wheel limit position, determine whether the current motor torque meets the initial torque requirements; When the steering wheel angle meets the initial angle requirement, the current motor speed meets the initial speed requirement, and the current motor torque meets the initial torque requirement, the steering wheel angle is taken as the current steering wheel limit position.

2. The steering wheel extreme position learning method according to claim 1, characterized in that, The step of determining the torque required for angle following based on the steering wheel angle, the target angle of the steering gear, and the steering wheel rotation speed includes: The steering gain speed is obtained by performing PID calculation based on the difference between the steering wheel angle and the target angle of the steering gear. The steering following speed is calculated by superimposing the steering gain speed and the steering wheel speed. The steering following speed is calculated using PID control to obtain the torque required for angle following.

3. The steering wheel extreme position learning method according to claim 1, characterized in that, The step of determining whether the steering wheel angle meets the initial angle requirements based on the steering wheel angle and the previous steering wheel extreme position includes: When the difference between the steering wheel angle and the previous steering wheel limit position meets the first preset range, a first steering angle flag value is obtained. The first steering angle flag value indicates that the steering wheel angle meets the initial steering angle requirements. When the difference between the steering wheel angle and the previous steering wheel limit position does not meet the first preset range, a second steering angle flag value is obtained. The second steering angle flag value indicates that the steering wheel angle does not meet the initial steering angle requirements.

4. The steering wheel extreme position learning method according to claim 3, characterized in that, The step of determining whether the current motor speed meets the initial speed requirements based on the current motor speed and the motor speed at the corresponding previous steering wheel extreme position includes: When the difference between the current motor speed and the motor speed at the corresponding previous steering wheel limit position meets the second preset range, and the first steering angle flag value lasts for a first preset time, a first speed flag value is obtained. The first speed flag value indicates that the current motor speed meets the initial speed requirements. When the difference between the current motor speed and the motor speed at the corresponding previous steering wheel limit position does not meet the second preset range, or the first steering angle flag value does not last for the first preset time, a second speed flag value is obtained. The second speed flag value indicates that the current motor speed does not meet the initial speed requirements.

5. The steering wheel extreme position learning method according to claim 3, characterized in that, The step of determining whether the current motor torque meets the initial torque requirement based on the current motor torque and the motor torque at the corresponding previous steering wheel limit position includes: When the difference between the current motor torque and the motor torque at the corresponding previous steering wheel limit position is greater than a preset torque change coefficient, the current motor torque is greater than a preset torque value, and the first steering angle flag value lasts for a second preset time, a first torque flag value is obtained. The first torque flag value indicates that the current motor torque meets the initial torque requirements. When the difference between the current motor torque and the motor torque at the corresponding previous steering wheel limit position is less than a preset torque change coefficient, the current motor torque is less than a preset torque value, or the first steering angle flag value has not lasted for a second preset time, a second torque flag value is obtained. The second torque flag value indicates that the current motor torque does not meet the initial torque requirements.

6. The steering wheel extreme position learning method according to claim 1, characterized in that, The method further includes: If the steering wheel angle does not meet the initial angle requirement, the current motor speed does not meet the initial speed requirement, or the current motor torque does not meet the initial torque requirement, the previous steering wheel limit position is taken as the current steering wheel limit position.

7. A steering wheel extreme position learning system, characterized in that, include: The input unit is used to obtain the steering wheel angle, current motor speed, and current motor torque. The first judgment unit is used to obtain the target angle of the steering gear and the steering wheel speed; The torque required for angle following is determined based on the steering wheel angle, the target angle of the steering gear, and the steering wheel speed. When the torque required for angle following meets the preset torque range, it is determined whether the steering wheel angle meets the initial angle requirements based on the steering wheel angle and the previous steering wheel limit position. The second judgment unit is used to determine whether the current motor speed meets the initial speed requirements based on the current motor speed and the motor speed at the corresponding previous steering wheel limit position. The third judgment unit is used to determine whether the current motor torque meets the initial torque requirements based on the current motor torque and the motor torque at the corresponding previous steering wheel limit position. The current steering wheel limit position determination unit is used to determine the steering wheel angle as the current steering wheel limit position when the steering wheel angle meets the initial angle requirement, the current motor speed meets the initial speed requirement, and the current motor torque meets the initial torque requirement.

8. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the steering wheel extreme position learning method as described in any one of claims 1 to 6.

9. A computer storage medium, characterized in that, The system stores computer-executable instructions for performing the steering wheel extreme position learning method as described in any one of claims 1 to 6.

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