Power-assisted control method and device for steering wheel, vehicle, storage medium and product

Abstract

The embodiment of the invention discloses a power-assisted control method and device for a steering wheel, a vehicle, a storage medium and a product, and the method comprises the steps that the angle of the steering wheel, the hand torque, the rotating speed of a power-assisted motor and the vehicle speed are obtained; inputting the angle of the steering wheel, the hand torque, the rotating speed of the power-assisted motor and the vehicle speed into a learning module to obtain a left limit angle and a right limit angle of the steering wheel; according to the numerical relationship between the current steering wheel angle of the steering wheel and the left limit angle and the numerical relationship between the current steering wheel angle of the steering wheel and the right limit angle, the rack state of the steering wheel is determined; based on the rack state, the angle of the steering wheel, the hand torque, the rotating speed of the assistance motor and the vehicle speed, the reduction assistance coefficient and the reverse torque are determined; and controlling the torque output of a power-assisted motor of the steering wheel based on the reduced power-assisted coefficient, and superposing the reverse torque on the torque output of the motor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intelligent vehicles, and particularly relates to a power control method and device for a steering wheel, a vehicle, a storage medium and a product. BACKGROUND

[0002] The purpose of electric power steering is to assist the driver to overcome the mechanical friction inside the steering mechanism and the ground friction, and to implement steering according to the expectation of the driver. Referring to Figure 1 The working principle is that physical signals such as the steering torque, the steering angle, the vehicle speed and the speed of the power motor of the steering wheel are collected by sensors, the processor processes the input signals through an internal algorithm and outputs a corresponding power current, then the power current is output to the power motor end and controls the motor to output a certain power torque, the power torque output by the motor is reduced in speed and increased in torque by a worm gear reducer, and then is added to the hand torque to overcome the resistance torque, helping the driver to control the vehicle steering as expected. The EPS system usually has functions such as basic power, active return, damping control, end protection, high-frequency compensation, and the end protection as a basic function in EPS reduces the impact on the end of the rack by reducing the power torque of the motor within the range of the end of the steering wheel, protects the end of the rack housing and reduces noise.

[0003] The existing end protection strategy usually takes the rotation angle, the rotation angular velocity and the steering torque of the steering wheel as inputs to determine whether the steering wheel reaches the end of the rack, so as to provide a power reduction control for the power motor of the steering wheel. However, this method only considers the working condition of the steering wheel towards the end of the rack, which will lead to the problem of insufficient power when the steering wheel is at the end of the rack and returns. In addition, when the power reduction function is applied to the power of the steering wheel, the power reduction is suddenly applied or suddenly stopped, resulting in obvious impact feeling of the end protection of the steering wheel in use. SUMMARY

[0004] Therefore, the present application provides a power control method and device for a steering wheel, a vehicle, a storage medium and a product.

[0005] The technical scheme of the present application is implemented as follows:

[0006] In one aspect, the present application provides a power control method for a steering wheel, which comprises the following steps:

[0007] obtaining the steering wheel angle, the steering torque, the speed of the power motor and the vehicle speed;

[0008] inputting the steering wheel angle, the steering torque, the speed of the power motor and the vehicle speed into a learning module to obtain the left limit angle and the right limit angle of the steering wheel;

[0009] determining a rack state of the steering wheel according to a numerical relationship between a current steering wheel angle of the steering wheel and the left limit angle, the right limit angle;

[0010] determining a descending assist force coefficient and a reverse torque based on the rack state, the steering wheel angle, the hand torque, the assist motor speed, and the vehicle speed;

[0011] controlling an assist motor torque output of the steering wheel based on the descending assist force coefficient, and superimposing the reverse torque on the motor torque output.

[0012] In some embodiments, the inputting of the steering wheel angle, the hand torque, the assist motor speed, and the vehicle speed into the learning module to obtain the left limit angle and the right limit angle of the steering wheel comprises:

[0013] in a case where the vehicle speed is less than a vehicle speed threshold, a vehicle signal is valid, the steering wheel angle is in a first preset angle interval, the hand torque is greater than a first hand torque threshold, and a duration in which the absolute value of the steering wheel speed is less than a first steering wheel speed threshold reaches a first preset time period, assigning the current steering wheel angle to the left limit angle;

[0014] in a case where the vehicle speed is less than a vehicle speed threshold, a vehicle signal is valid, the steering wheel angle is in a second preset angle interval, the hand torque is less than a second hand torque threshold, and a duration in which the absolute value of the steering wheel speed is less than a first steering wheel speed threshold reaches a second preset time period, assigning the current steering wheel angle to the right limit angle, wherein the first preset angle interval and the second angle interval are symmetrical about the origin, and the first hand torque threshold and the second hand torque threshold are opposite numbers.

[0015] The embodiments of the present application ensure accurate acquisition of the limit angles of left and right steering of the steering wheel under safe and reliable conditions by judging the conditions and time requirements. The system uses a symmetrical design principle to handle left and right steering, ensuring the consistency of protection on both sides of the steering system. Through comprehensive judgment of multiple dimensions such as vehicle speed, signal validity, angle interval, hand torque, and speed, the occurrence of false learning and incorrect recording of limit angles is avoided. Accurate recording of the limit angles provides a basis parameter for subsequent end protection control, effectively preventing damage to mechanical components of the steering system due to excessive rotation, and optimizing the operation feel of the driver at the steering limit position. The entire learning process is highly automated and does not require human intervention, improving the reliability and user experience of the system.

[0016] In some embodiments, after the inputting of the steering wheel angle, the hand torque, the assist motor speed, and the vehicle speed into the learning module to obtain the left limit angle and the right limit angle of the steering wheel, the method further comprises:

[0017] in a case where the duration that the steering wheel angle exceeds the left limit angle reaches a third preset time period and the absolute value of the steering wheel rotation speed is less than a second steering wheel rotation speed threshold, updating the left limit angle by using a current steering wheel angle;

[0018] in a case where the duration that the steering wheel angle exceeds the right limit angle reaches a fourth preset time period and the absolute value of the steering wheel rotation speed is less than a second steering wheel rotation speed threshold, updating the right limit angle by using a current steering wheel angle.

[0019] The embodiments of the application avoid the risk of normal steering operation triggering parameter updating by mistake by introducing the double judgment of the rotation speed threshold and the time duration condition, and ensure the stability of the system in complex driving conditions. The dynamic updating mechanism cooperates with the state determination module and the factor limiting module, and finally realizes the optimized control effect of protecting the mechanical structure and not affecting the driving feeling.

[0020] In some embodiments, the method further comprises:

[0021] in a case where the absolute difference between the left limit angle and the right limit angle is greater than a preset angle threshold, re-executing the assignment process of the left limit angle and the right limit angle.

[0022] The embodiments of the application can continuously monitor and correct the left and right limit angles of the steering system, ensure the symmetry and accuracy of the steering stroke, effectively solve the stroke deviation problem caused by sensor errors and mechanical wear, improve the reliability and service life of the steering system, and at the same time provide consistent steering feeling for the driver.

[0023] In some embodiments, the rack state of the steering wheel is determined according to the numerical relationship between the current steering wheel angle of the steering wheel and the left limit angle and the right limit angle, comprising:

[0024] in a case where the steering wheel angle does not enter the end stroke region, determining the rack state as a normal state;

[0025] in a case where the steering wheel angle is in the end stroke region and the steering wheel angle moves towards the end limit position, determining the rack state as an entry state;

[0026] in a case where the steering wheel angle is in the end stroke region and the steering wheel angle moves away from the end limit position, determining the rack state as an exit state;

[0027] in a case where the system meets the disabling condition, determining the rack state as a disabled state.

[0028] The embodiments of the present application realize intelligent protection of the end region of the electric power steering system through accurate state division and targeted control strategy. The system can dynamically adjust the protection strength according to the real-time working condition, optimize the steering feeling while ensuring the safety of the mechanical structure, and avoid the common feeling mutation problem in the traditional end protection method.

[0029] In some embodiments, the reduced assist force coefficient is obtained by the following steps:

[0030] In the case that the rack state is in the entering state, a first reduced assist force coefficient is obtained based on the product of a vehicle speed coefficient, an angle coefficient and a rotation speed coefficient, wherein the vehicle speed coefficient is related to the vehicle speed, the rotation speed coefficient is related to the assist motor rotation speed, and the angle coefficient is determined by the ratio of the steering wheel angle to the end and a preset scaling factor;

[0031] In the case that the rack state is in the exiting state, a second reduced assist force coefficient is determined based on the comparison result of the hand torque and a third hand torque threshold;

[0032] In the case that the rack state is in the regular state or the disabled state, a third reduced assist force coefficient is output, and the effect of the third reduced assist force coefficient is not to limit the assist motor output.

[0033] The embodiments of the present application accurately control the assist force output through multi-parameter fusion calculation, optimize the steering feeling while protecting the mechanical structure, effectively reduce the mechanical impact risk, improve the driving comfort, and prolong the service life of the steering system.

[0034] In some embodiments, the reverse torque is obtained by the following steps:

[0035] In the case that the rack state is in the entering state or the exiting state, a basic torque is determined according to the linear relationship between the steering wheel angle and the end limit position;

[0036] The basic torque is adjusted based on the product of the absolute value of the assist motor rotation speed and a hand torque gain factor to obtain a reverse torque;

[0037] In the case that the rack state is in the disabled state or the regular state, the reverse torque is set to zero.

[0038] The embodiments of the present application accurately determine the state, intelligently calculate and apply appropriate reverse torque when the rack approaches the end, effectively reduce the mechanical impact and optimize the steering feeling. In the non-end region, the reverse torque is cancelled to ensure that the normal steering assist is not affected.

[0039] In another aspect, the embodiments of the present application provide a power control device for a steering wheel, the device comprising:

[0040] a sensor module configured to acquire a steering wheel angle, a hand torque, a power-assisted motor speed, and a vehicle speed;

[0041] a learning module configured to input the steering wheel angle, the hand torque, the power-assisted motor speed, and the vehicle speed into the learning module, and acquire a left limit angle and a right limit angle of the steering wheel;

[0042] a limiting module configured to determine a rack state of the steering wheel according to a numerical relationship between a current steering wheel angle of the steering wheel and the left limit angle and the right limit angle;

[0043] determine a power reduction coefficient and a reverse torque based on the rack state, the steering wheel angle, the hand torque, the power-assisted motor speed, and the vehicle speed;

[0044] control a power-assisted motor torque output of the steering wheel based on the power reduction coefficient, and superimpose the reverse torque on the motor torque output.

[0045] In still another aspect, an embodiment of the present application provides a vehicle including a steering wheel, a power-assisted motor, a memory, and a processor, wherein the power-assisted motor is configured to output a power-assisted torque to a rack of the steering wheel, the memory stores a computer program capable of running on the processor, and the processor implements part or all steps of the power-assisted control method of the steering wheel when executing the program.

[0046] In still another aspect, an embodiment of the present application provides a computer readable storage medium having a computer program stored thereon, and the computer program is executed by a processor to implement part or all steps of the power-assisted control method of the steering wheel.

[0047] In still another aspect, an embodiment of the present application provides a computer program including computer readable code, and when the computer readable code is run in a vehicle, a processor in the vehicle executes the code to implement part or all steps of the power-assisted control method of the steering wheel.

[0048] In still another aspect, an embodiment of the present application provides a computer program product including a non-transitory computer readable storage medium storing a computer program, and when the computer program is read and executed by a computer, part or all steps of the power-assisted control method of the steering wheel are implemented.

[0049] The embodiment of the application obtains the left and right limit angles of the rack accurately through a learning module by collecting various steering parameters of the steering wheel angle, hand torque, assist motor speed and vehicle speed of the vehicle, identifies the state of the rack based on the left and right limit angles, determines the assist reduction coefficient and the reverse torque for different rack states and steering parameters, so that the assist force coefficient can be used to dynamically limit the steering wheel assist force output torque under various working conditions, so that the steering wheel assist force limitation can cover various working conditions in the vehicle driving process, and the reverse torque is superimposed on the assist motor torque output to avoid the end impact touch feeling caused by the lack of buffer feeling when the hand torque is large, and the hand feeling of the steering wheel assist force is optimized. BRIEF DESCRIPTION OF DRAWINGS

[0050] The drawings incorporated into the specification and forming a part of the specification, show embodiments consistent with the present application, and together with the specification, serve to explain the technical solutions of the present application.

[0051] Figure 1 It is a schematic diagram of the architecture of a vehicle steering wheel assist system in the prior art;

[0052] Figure 2 It is a schematic diagram of the implementation process of a steering wheel assist control method provided by the embodiment of the application;

[0053] Figure 3 It is a system architecture diagram of a steering wheel assist control system provided by the embodiment of the application;

[0054] Figure 4 It is a schematic diagram of a rack structure provided by the embodiment of the application;

[0055] Figure 5 It is a principle diagram of a request torque method of an assist motor provided by the embodiment of the application;

[0056] Figure 6 It is a schematic diagram of the composition structure of a steering wheel assist control device provided by the embodiment of the application;

[0057] Figure 7 It is a schematic diagram of the hardware entity of a vehicle provided by the embodiment of the application. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions of the present application are further described in detail below in combination with the drawings and embodiments, and the described embodiments should not be regarded as limiting the present application, and all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0059] In the following description, reference is made to "some embodiments", which describe a subset of all possible embodiments, but which can be understood as possibly being the same or different subsets of all possible embodiments, and which can be combined with each other, without conflict, if so desired.

[0060] The terms "first / second / third" are only to distinguish similar objects, and do not represent a specific order of the objects. It can be understood that the "first / second / third" can be interchanged in a specific order or sequence as allowed, so that the embodiments of the application described herein can be implemented in an order other than that illustrated or described herein.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the specification is for the purpose of describing the application only and is not intended to be limiting of the application.

[0062] The embodiments of the application provide a power control method of a steering wheel, which can be executed by a processor of a vehicle-mounted device. The vehicle-mounted device can be a server, a notebook computer, a tablet computer, a desktop computer, a smart television, a set-top box, a mobile device (such as a mobile phone, a portable video player, a personal digital assistant, a dedicated message device, a portable game device) and the like. Figure 1 The implementation flowchart of the power control method of the steering wheel provided by the embodiments of the application is shown in FIG. 1. Figure 1 The method comprises the following steps.

[0063] In step 101, the steering wheel angle, the hand torque, the power motor speed and the vehicle speed are obtained.

[0064] In the embodiments of the application, the steering wheel angle is an angle value of the steering wheel rotation, which represents the rotation degree of the steering wheel relative to the center position, and the unit is degree (°). The hand torque is a torque value applied by the driver on the steering wheel, which represents the force size of the driver operating the steering, and the unit is Newton-meter (Nm). The power motor speed is a rotation speed value of the output shaft of the power motor, which represents the motor running state, and the unit is degree per second (° / s) or revolutions per minute (rpm). The vehicle speed is a speed value of the vehicle running, which represents the whole vehicle dynamic state, and the unit is kilometers per hour (km / h).

[0065] The system collects the required parameters in real time by integrating the sensor module, measures the steering wheel angle and hand torque using the TAS sensor, and can directly transmit to the ECU at a sampling frequency of, for example, 100 Hz; measures the speed of the assist motor through the photoelectric encoder; at the same time, the ECU acquires the vehicle speed data from the CAN bus at a period of, for example, 10 ms. This process ensures that all input signals are filtered to eliminate noise interference and provide effective and synchronized data input for the learning module.

[0066] Step 102, input the steering wheel angle, hand torque, assist motor speed, and vehicle speed into the learning module to obtain the left and right limit angles of the steering wheel.

[0067] In the embodiments of the present application, the learning module is a functional unit in the system, responsible for learning and updating the left and right limit angles of the steering wheel through algorithms, including a self-learning sub-module and an update learning sub-module. The self-learning sub-module is used to determine the left and right limit angles when the assist motor is just started, and the update learning sub-module is used to update the left and right limit angles after the assist motor is started. The left limit angle is the maximum angle value of the steering wheel turning to the left, representing the limit position of the left mechanical stroke of the rack. The right limit angle is the maximum angle value of the steering wheel turning to the right, representing the limit position of the right mechanical stroke of the rack.

[0068] After the system inputs the steering wheel angle, hand torque, assist motor speed, and vehicle speed into the learning module, it first starts the self-learning sub-module when the software is first run. When the vehicle speed is less than a threshold value, the vehicle voltage is normal, and all signals are valid, the system determines whether the steering wheel angle is in a predetermined interval (for example, 380°≤θ≤500° for left limit learning), while monitoring whether the absolute value of the steering wheel speed (converted from the assist motor speed and the worm gear reduction ratio) is below a threshold value and whether the hand torque exceeds a threshold value, and maintaining this state for a certain period of time. If the conditions are met, the system assigns the current steering wheel angle to the left or right limit angle, otherwise the learning process is reset. Then, the system checks whether the absolute difference between the left and right limit angles is less than a threshold value to ensure that the left and right strokes are consistent. The update learning sub-module dynamically corrects the limit angles when the angle sensor is abnormal: when it is detected that the steering wheel angle continuously exceeds the original limit angle by a certain value and the speed is below a threshold value, the system reassigns and stores the value to the memory. Finally, the system outputs the learned left and right limit angles and sets the flag position to 1, and the memory already has valid values of the left and right limit angles.

[0069] Step 103, determine the rack state of the steering wheel according to the numerical relationship between the current steering wheel angle of the steering wheel and the left and right limit angles.

[0070] In the embodiments of the present application, the rack state is the current running state value of the rack end protection function, including disable (non-activated), normal (activated and not entering the end), entry (entering the end and moving towards the limit), and exit (entering the end but moving away from the limit)

[0071] The system performs a state determination module according to the numerical relationship between the current steering wheel angle and the left limit angle and the right limit angle. If the system is not activated, the disable state is output. If the steering wheel angle does not enter the end stroke range, the normal state is output. If the current steering wheel angle is in the end range and the assist motor speed direction points to the limit position, the entry state is output. If the current steering wheel angle is in the end range but the speed direction deviates from the limit position. The system adds a low-pass filter in the exit state to ensure smooth state switching and avoid sudden changes in hand feeling.

[0072] In step 104, based on the rack state, the steering wheel angle, the hand torque, the assist motor speed, and the vehicle speed, the system determines the assist reduction coefficient and the reverse torque.

[0073] In the embodiments of the present application, the assist reduction coefficient is a scaling factor value in the range [0, 1], which is used to reduce the output torque of the assist motor. The reverse torque is an additional torque value, which acts in the opposite direction of the basic assist and provides damping effect.

[0074] Based on the rack state, the steering wheel angle, the hand torque, the assist motor speed, and the vehicle speed, the system processes through the factor limiting module and the reverse torque calculation module. In the entry state or the exit state, the system calculates the vehicle speed coefficient (which decreases with the increase of the vehicle speed), the angle coefficient (which decreases linearly with the proximity to the limit position), and the speed coefficient (which decreases with the increase of the speed), and the three are multiplied to obtain the assist reduction coefficient. At the same time, the system calculates the reverse torque in the exit or entry state, according to the assist motor speed, the angle proximity, and the hand torque gain factor kr, and outputs the reverse torque, which increases with the increase of the speed and the proximity. The system applies a low-pass filter to all outputs to ensure the continuity of the coefficient and torque changes.

[0075] In step 105, the assist motor torque output of the steering wheel is controlled based on the assist reduction coefficient, and the reverse torque is superimposed on the motor torque output.

[0076] In an embodiment of the present application, the system first applies the power reduction coefficient to the motor request torque end, and multiplies the power reduction coefficient by the sum of the torque requests of the basic power assistance, return control and other functions to achieve a reduction in torque output (for example, when the power reduction coefficient = 0.5, the output torque is halved). Subsequently, the system superimposes a reverse torque on the motor torque output end, whose sign is opposite to the basic power assistance and is only activated when entering or exiting the state. This process is executed in real time by the torque synthesis algorithm of the ECU, and the control command is sent via the CAN message 0x2A0. Ultimately, the system ensures that the torque output of the power assist motor meets the protection requirements, while avoiding mutations through smoothing filtering.

[0077] The embodiment of the present application collects multiple steering parameters such as the steering wheel angle, hand torque, power-assist motor speed and vehicle speed of the vehicle steering wheel to accurately obtain the left and right limit angles of the rack through a learning module, identifies the rack state based on the left and right limit angles, and determines the power-assistance reduction coefficient and reverse torque for different rack states and steering parameters. In this way, the power-assistance output torque of the steering wheel can be dynamically limited under various working conditions by utilizing the power-assistance coefficient, so that the steering wheel power-assistance limitation can cover various working conditions during vehicle driving. At the same time, the reverse torque is superimposed on the power-assist motor torque output to avoid the end impact touch caused by the lack of buffering when the hand torque is large, thereby optimizing the feel of the steering wheel power-assistance.

[0078] In some embodiments, step 102 includes:

[0079] Step 1021, when the vehicle speed is less than the vehicle speed threshold, and the vehicle signal is valid, and the steering wheel angle is in the first preset angle range, and the hand torque is greater than the first hand torque threshold, and the duration period during which the absolute value of the steering wheel speed is less than the first steering wheel speed threshold reaches the first preset time period, the current steering wheel angle is assigned to the left limit angle.

[0080] In the embodiment of the present application, the vehicle speed threshold refers to a pre-set upper speed limit value, which is used to determine whether the vehicle is in a low-speed state. The effective vehicle signal indicates that the various sensors and systems of the vehicle are working normally and the signal is reliable and available. The first preset angle interval refers to the angle range of the steering wheel turning to the left, which is used to determine whether the steering wheel is in a suitable position for learning the left limit angle. The first hand torque threshold is used to determine the minimum force value applied by the driver to the hand torque. The first steering wheel speed threshold is a critical value for determining whether the steering wheel speed is in a stable state. The first preset time period is the shortest length of time that the judgment condition needs to be continuously met. The left limit angle refers to the maximum allowable angle of the steering wheel turning to the left.

[0081] The system first detects whether the current vehicle speed is less than a preset speed threshold, and checks whether the signals of the vehicle sensors are valid. Then the system determines whether the steering wheel angle is within a first preset angle interval, and detects whether the hand torque is greater than a first hand torque threshold. Meanwhile, the system calculates the absolute value of the steering wheel rotation speed, and determines whether the value is less than a first steering wheel rotation speed threshold. The system continuously monitors all the above conditions, and when these conditions are met simultaneously and the duration reaches a first preset time period, the system assigns the current steering wheel angle value as the left limit angle.

[0082] In step 1022, the current steering wheel angle is assigned to the right limit angle in the case that the vehicle speed is less than the speed threshold, the vehicle signals are valid, the steering wheel angle is within a second preset angle interval, the hand torque is less than a second hand torque threshold, and the absolute value of the steering wheel rotation speed is less than a first steering wheel rotation speed threshold for a duration reaching a second preset time period, wherein the first preset angle interval and the second angle interval are symmetric about the origin, and the first hand torque threshold and the second hand torque threshold are opposite numbers.

[0083] In the embodiments of the present application, the second preset angle interval refers to the angle range of the steering wheel turning to the right, which is symmetric about the origin with the first preset angle interval. The second hand torque threshold is the minimum reverse force value applied by the driver on the hand torque, which is equal in value but opposite in sign to the first hand torque threshold. The second preset time period is the minimum time length for which the conditions need to be continuously met, which can be the same as or different from the first preset time period. The right limit angle refers to the maximum allowed angle of the steering wheel turning to the right.

[0084] The system first detects whether the current vehicle speed is less than a preset speed threshold, and checks whether the signals of the vehicle sensors are valid. Then the system determines whether the steering wheel angle is within a second preset angle interval, which is symmetric about the origin with the first preset angle interval. The system detects whether the hand torque is less than the second hand torque threshold (i.e., the reverse torque). Meanwhile, the system calculates the absolute value of the steering wheel rotation speed, and determines whether the value is less than a first steering wheel rotation speed threshold. The system continuously monitors all the above conditions, and when these conditions are met simultaneously and the duration reaches a second preset time period, the system assigns the current steering wheel angle value as the right limit angle. This process ensures that in the stable state of low vehicle speed, reliable signals, appropriate steering wheel position, and sufficient reverse torque applied by the driver, the limit position of the steering wheel turning to the right is accurately recorded.

[0085] The application embodiment ensures accurate acquisition of the limit angle of left and right rotation of the steering wheel under safe and reliable conditions through strict judgment conditions and time requirements. The system adopts a symmetrical design principle to process left and right steering, ensuring the consistency of protection on both sides of the steering system. Through comprehensive judgment of multiple dimensions such as vehicle speed, signal effectiveness, angle interval, hand torque and rotation speed, the occurrence of false learning and incorrect recording of the limit angle is avoided. The accurate limit angle recorded provides a basic parameter for subsequent end protection control, which can effectively prevent the mechanical parts of the steering system from being damaged due to excessive rotation, and at the same time optimizes the operation feeling of the driver at the limit position of steering. The entire learning process is highly automated and does not require human intervention, improving the reliability and user experience of the system.

[0086] In some embodiments, after the step 102, the method further comprises:

[0087] Step 201, in the case that the duration of the steering wheel angle exceeding the left limit angle reaches a third preset time period, and the absolute value of the steering wheel rotation speed is less than a second steering wheel rotation speed threshold, the left limit angle is updated by using the current steering wheel angle.

[0088] In the application embodiment, the steering wheel angle refers to the current rotation position of the steering wheel measured by the torque and angle sensor (TAS), and the unit is degree. The left limit angle refers to the maximum mechanical limit angle of the left rotation of the steering mechanism determined by the system through learning, which is stored in the non-volatile memory (NVM). The third preset time period is a time threshold set by the system for judging whether the steering wheel is continuously in an abnormal position state. The absolute value of the steering wheel rotation speed refers to the rotation speed of the steering column without considering the rotation direction, which is obtained by converting the rotation speed of the assist motor and the worm gear reduction ratio. The second steering wheel rotation speed threshold is a rotation speed threshold set by the system for judging whether the steering operation is in a quasi-static condition.

[0089] The system continuously monitors the steering wheel angle signal, and when it is detected that the current angle value continuously exceeds the stored left limit angle for a third preset time period, and the absolute value of the steering wheel rotation speed measured by the photoelectric encoder is less than the second steering wheel rotation speed threshold, the ECU determines that the left limit angle needs to be updated. At this time, the system writes the current steering wheel angle value to the designated storage area of the NVM, overwriting the original left limit angle value. Before updating, CRC check is performed to ensure data integrity, and if the check fails, the backup sector is written. After the update is completed, the system recalculates the end stroke range and updates the reference benchmark of the state judgment module.

[0090] Step 202, in the case that the duration of the steering wheel angle exceeding the right limit angle reaches a fourth preset time period, and the absolute value of the steering wheel rotation speed is less than the second steering wheel rotation speed threshold, the right limit angle is updated by using the current steering wheel angle.

[0091] In the embodiment of the present application, the system monitors the angle state of the steering wheel turning right in parallel. When it is detected that the angle value continuously exceeds the stored right limit angle for a duration reaching a fourth preset time period, and at the same time, the condition that the absolute value of the steering wheel speed is less than the second steering wheel speed threshold is met, the ECU starts the right limit angle updating process. The system first verifies the validity range of the current angle value, and then writes the verified current angle value to the corresponding storage area of the NVM. After updating, the system immediately verifies whether the absolute difference between the left and right limit angles is less than the safety threshold. If it exceeds the threshold, the self-learning module is triggered to reinitialize the learning process. The updating operation synchronously triggers the state reset of the alarm module, ensuring that the human-machine interaction prompt is consistent with the latest mechanical limit.

[0092] The embodiment of the present application avoids the risk of mis-triggering parameter updating in normal steering operation by introducing the double judgment of speed threshold and time duration condition, ensuring the stability of the system in complex driving conditions. The dynamic updating mechanism cooperates with the state judgment module and the factor limiting module, and finally realizes the optimized control effect of protecting the mechanical structure and not affecting the driving feeling.

[0093] In some embodiments, the method further comprises: in the case that the absolute difference between the left limit angle and the right limit angle is greater than a preset angle threshold, re-executing the assignment process of the left limit angle and the right limit angle.

[0094] In the embodiment of the present application, the system reads the assigned left limit angle and right limit angle from the memory and calculates the absolute difference between them. This calculation process is automatically executed after each angle assignment. The system compares the calculated absolute difference with the preset angle threshold stored in the memory. This comparison operation is automatically completed by the control unit as a basis for judging whether the angle value needs to be relearned. When the comparison result shows that the absolute difference exceeds the preset threshold, the system automatically resets the learning flag, clears the original angle value, and re-executes the complete left limit angle and right limit angle learning process. This process ensures that the steering system always maintains an accurate stroke range.

[0095] The embodiment of the present application can continuously monitor and correct the left and right limit angles of the steering system, ensuring the symmetry and accuracy of the steering stroke. This closed-loop control mechanism effectively solves the stroke deviation problem caused by sensor errors and mechanical wear, improves the reliability and service life of the steering system, and at the same time provides consistent steering feeling for the driver.

[0096] In some embodiments, the step 103 comprises:

[0097] Step 1031, in the case where the steering wheel angle does not enter the end stroke region, the rack state is determined as a normal state.

[0098] In the embodiment of the present application, the system continuously monitors the steering wheel angle value through the TAS sensor, and compares and calculates the value with the pre-learned and stored left and right limit angle values. When it is judged that the current steering wheel angle does not enter the end stroke region, the system marks the rack state as a normal state. In this state, the system does not activate any end protection measures, maintains normal assist motor output, and all assist functions such as basic assist, return control, etc. are operated according to standard parameters. The system will continuously monitor the steering wheel angle change at the same time, preparing for possible state conversion.

[0099] Step 1032, in the case where the steering wheel angle is in the end stroke region and the steering wheel angle moves towards the end limit position, the rack state is determined as an entering state.

[0100] In the embodiment of the present application, the end limit position refers to the value of the maximum left and right turning angle of the steering wheel obtained through the self-learning module and stored in the NVM, representing the limit position of the rack within the range allowed by the mechanical structure. The entering state indicates that the rack has entered the end protection region and is moving towards the limit position.

[0101] The system judges that the current steering wheel angle has entered the end stroke region through real-time calculation, and judges that the steering wheel is moving towards the end limit position through the speed direction and position change trend of the assist motor measured by the photoelectric encoder (the speed and position change directions are consistent). At this time, the system marks the rack state as an entering state and activates the end protection algorithm. The system will calculate the assist reduction coefficient according to the vehicle speed coefficient, angle coefficient and speed coefficient, and generate a reverse torque opposite to the direction of the basic assist, both of which act on the motor request torque end to realize gradual assist limitation and protection.

[0102] Step 1033, in the case where the steering wheel angle is in the end stroke region and the steering wheel angle moves away from the end limit position, the rack state is determined as an exiting state.

[0103] In the embodiment of the present application, the exiting state indicates that the rack is in the end stroke region, but the steering wheel angle change trend shows that it is moving away from the end limit position. Moving away from the end limit position refers to the motion state in which the steering wheel rotation direction is opposite to the limit position direction through the assist motor speed measurement value.

[0104] The system detects that the steering wheel angle is in the end stroke region, but the direction of the assist motor speed measured by the photoelectric encoder shows that the steering wheel is moving away from the limit position. At this time, the system marks the rack state as the exit state. In this state, the system no longer uses the conventional assist reduction coefficient calculation method, but dynamically adjusts the assist reduction coefficient according to the hand torque measured by the TAS sensor, and smoothes the state transition process through a low-pass filter to ensure a natural transition in hand feeling.

[0105] Step 1034, in the case where the system meets the disable condition, determining the rack state as the disable state.

[0106] In the embodiments of the present application, the disable condition refers to a judgment condition for completely closing the end protection function when the system detects certain abnormal conditions or specific working conditions, including but not limited to high vehicle speed, sensor signal failure, system voltage anomaly, etc. The disable state indicates a system state in which the end protection function is forcibly closed.

[0107] The system continuously monitors multiple operating parameters, and when it detects that the disable condition is met (such as vehicle speed exceeding a threshold, sensor signal invalid, system voltage anomaly, etc.), it marks the rack state as disable. In this state, the system completely closes the end protection function and does not apply any assist reduction coefficient or reverse torque, only retaining the basic assist function. The system will record the disable reason at the same time and send state information through the CAN bus. When the disable condition is removed, the system will automatically reactivate the end protection function and restore the appropriate state according to the current steering wheel angle and speed.

[0108] The embodiments of the present application achieve intelligent protection of the end region of the electric power steering system through precise state division and targeted control strategy. The system can dynamically adjust the protection strength according to the real-time working condition, optimize the steering feeling while ensuring the safety of the mechanical structure, and avoid the common sudden change in hand feeling in traditional end protection methods.

[0109] In some embodiments, the assist reduction coefficient is obtained by the following steps:

[0110] Step 301, in the case where the rack state is in the entry state, obtaining a first assist reduction coefficient based on the product of a vehicle speed coefficient, an angle coefficient, and a speed coefficient, wherein the vehicle speed coefficient is related to the vehicle speed, the speed coefficient is related to the assist motor speed, and the angle coefficient is determined by the ratio of the steering wheel angle to the end and a preset scaling factor.

[0111] In the embodiments of the present application, the vehicle speed coefficient is a proportional factor related to the vehicle driving speed, used to adjust the degree of assistance limitation according to the vehicle speed. The angle coefficient is a proportional factor calculated by the ratio of the current steering wheel angle to the end limit angle, reflecting the degree of approaching the end of the steering position. The speed coefficient is a proportional factor related to the speed of the assistance motor, used to adjust the degree of assistance limitation according to the steering speed. The first reduction assistance coefficient is a comprehensive proportional factor obtained by multiplying the above three coefficients, used to reduce the motor assistance output.

[0112] When the rack state is in the entering state, the system first calculates the vehicle speed coefficient, which decreases with the increase of the vehicle speed, realizing more strict assistance limitation when driving at high speed. Then the angle coefficient is calculated, which is obtained by multiplying the ratio of the current steering wheel angle to the end limit angle by a preset scaling factor, reflecting the degree of approaching the end of the steering position. Then the speed coefficient is calculated, which decreases with the increase of the speed of the assistance motor, reflecting the need for stronger assistance limitation when steering quickly. Finally, the three coefficients are multiplied to obtain the first reduction assistance coefficient, which acts on the motor request torque end, realizing the effect of gradually reducing the assistance output.

[0113] In step 302, when the rack state is in the exiting state, a second reduction assistance coefficient is determined based on the comparison result of the hand torque and a third hand torque threshold.

[0114] In the embodiments of the present application, the second reduction assistance coefficient is an assistance limitation proportional factor determined according to the comparison result of the hand torque and a preset threshold. The third hand torque threshold is a critical value obtained by real vehicle calibration, used to judge the strength of the driver's steering intention.

[0115] When the rack state is in the exiting state, the system continuously monitors the hand torque input signal. When the hand torque is greater than the third hand torque threshold, the system judges that the driver has strong steering intention, and sets the second reduction assistance coefficient to 1, indicating that the assistance output is not limited. When the hand torque is less than the threshold, the system calculates the second reduction assistance coefficient according to the size of the hand torque in a quadratic function relationship, and adjusts the change rate through a gain factor, realizing a smooth assistance recovery process. The coefficient acts on the motor request torque end, ensuring smooth transition of the assistance output when exiting the end region.

[0116] In step 303, when the rack state is in the normal state or the disabled state, a third reduction assistance coefficient is output, and the effect of the third reduction assistance coefficient is to not limit the output of the assistance motor.

[0117] In the embodiments of the present application, the system directly outputs a third reduction assistance coefficient 1 when the rack state is in a normal state or a disabled state. The coefficient acts on the motor request torque end, indicating that no restriction is made on the assistance motor output, and the normal assistance output characteristic is maintained. In the normal state, the system continuously monitors the steering parameters to prepare for possible state conversion. In the disabled state, the system suspends all end protection functions and only maintains basic monitoring functions.

[0118] In the embodiments of the present application, the accurate control of assistance output is realized through multi-parameter fusion calculation, the steering feel is optimized while the mechanical structure is protected, the mechanical impact risk is effectively reduced, the driving comfort is improved, and the service life of the steering system is prolonged.

[0119] In some embodiments, the reverse torque is obtained by the following steps:

[0120] Step 401, when the rack state is in the entering state or the exiting state, a basic torque is determined according to the linear relationship between the steering wheel angle and the end limit position.

[0121] In the embodiments of the present application, when the rack state is in the entering state or the exiting state, the current steering wheel angle and the pre-learned end limit position are first obtained. The system calculates the proportional relationship between the steering wheel angle and the end limit position through a linear interpolation algorithm, and determines a basic torque value according to a preset torque curve. The basic torque serves as the initial value of the reverse torque, and its size is proportional to the degree to which the steering wheel approaches the end limit position. The closer the steering wheel approaches the end limit position, the larger the basic torque value. The system stores the calculated basic torque value in a temporary variable for subsequent steps.

[0122] Step 402, the basic torque is adjusted based on the product of the absolute value of the assistance motor speed and the hand torque gain factor to obtain the reverse torque.

[0123] In the embodiments of the present application, the current assistance motor speed is obtained and the absolute value operation is performed to ensure that it is positive. At the same time, the system calculates a hand torque gain factor according to the measured hand torque value, and the factor increases with the increase of the hand torque. The system multiplies the absolute value of the assistance motor speed by the hand torque gain factor to obtain an adjustment coefficient. Then the adjustment coefficient is multiplied by the obtained basic torque to obtain the final reverse torque value. The reverse torque will increase with the increase of the assistance motor speed and the hand torque, providing appropriate damping effect in the end region, optimizing the steering feel and reducing mechanical impact.

[0124] Step 403, when the rack state is in the disabled state or the normal state, the reverse torque is set to zero.

[0125] In the embodiments of the present application, the system continuously monitors the rack state, and sets the reverse torque to zero when it is determined that the current state is the disabled state or the normal state. In this state, the system does not apply any reverse torque, ensuring that the normal steering assist function of the non-terminal region is not affected. The system achieves smooth switching between different states through state machine management. When switching from the entry state or the exit state to the disabled state or the normal state, the reverse torque is smoothly transitioned to zero through a low-pass filter, avoiding the discomfort of steering feel caused by torque mutation.

[0126] The embodiments of the present application intelligently calculate and apply appropriate reverse torque when the rack approaches the terminal end through accurate state judgment, effectively reducing mechanical impact and optimizing steering feel. In the non-terminal region, the reverse torque is cancelled, ensuring that the normal steering assist is not affected.

[0127] In some embodiments, the method further comprises: when the steering wheel angle enters the terminal stroke range or approaches the terminal limit position, triggering the alarm module to output a prompt signal.

[0128] In the embodiments of the present application, the system acquires the steering wheel angle θ in real time through the sensor module, and compares it with the terminal limit position θz, θm and the terminal stroke range △θ stored in the learning module. When the steering wheel angle θ enters the terminal stroke range (i.e. θ = θz-△θ or θ = θm+△θ) or approaches the terminal limit position (i.e. θ = θz-5° or θ = θm+5°), the system determines that the current state meets the alarm triggering condition. Subsequently, the alarm module is activated, and the system outputs a visual prompt signal (such as displaying “entering the terminal” or “reaching the terminal, please pay attention”) through the vehicle central control screen, generates an audible prompt signal (such as a beeping sound) at the same time, and maintains a preset duration (for example, 1 second or 2 seconds). The entire process is executed with a software main loop cycle of 10 milliseconds, ensuring real-time and accuracy.

[0129] The embodiments of the present application provide active warnings when the driver operates the steering system by monitoring the steering wheel angle in real time and accurately triggering the alarm module, effectively reducing the risk of the rack colliding with the mechanical terminal. Combined with the control of the assist reduction coefficient and the reverse torque, the system optimizes the steering feel while protecting the steering mechanism, prolongs the service life of the steering system, and improves the overall driving safety.

[0130] In some embodiments, with reference to Figure 3The application provides a rack end protection system, which is divided into a sensor module, a learning module, a limiting module and an alarm module. The sensor module collects the steering wheel angle, hand torque, assist motor speed and vehicle speed, wherein the vehicle speed is received by the ECU from the CAN network, and the lower end of the steering wheel column is rigidly connected with the assist motor, so that the steering wheel speed is linearly related to the assist motor speed. The learning module is divided into a self-learning module and an updating learning module, and the functions of the self-learning module and the updating learning module are to learn the left and right limit angles of the rack end and to update the left and right limit angles respectively. The limiting module is divided into a state judgment module, a reverse torque calculation module and a factor limiting module. The state judgment module judges the current state of the rack according to the left and right limit angles of the steering wheel and the end stroke, so as to output the corresponding reverse torque and the reduction assist coefficient. The reverse torque calculation module outputs the corresponding reverse assist torque according to the assist motor speed, the current state and the hand torque, so as to improve the hand feeling in the end range. The factor limiting module outputs the reduction assist coefficient according to the current state, the steering wheel angle and the speed. The alarm module is a supplementary function, which prompts the driver whether to reach the end stroke range and the end limit angle through sound and the central control screen.

[0131] The sensor module includes a TAS (Torque and Angle Sensor) sensor, an optical encoder and a Hall wheel speed sensor, which respectively measure the hand torque and angle of the steering wheel, the assist motor speed and the vehicle speed. The hand torque, angle and assist motor speed are directly transmitted to the ECU for calculation after being measured by the sensor, and the vehicle speed is sent to the ECU of the EPS system through the CAN network of the whole vehicle. The learning module and the limiting module need to use the steering wheel speed as a judgment condition. Considering the physical structure of the EPS, the lower end of the steering column is rigidly connected with the worm and gear reducer, so that the steering wheel speed is linearly related to the assist motor speed, and the specific correlation coefficient is equal to the worm and gear reduction ratio.

[0132] The left and right limit angles are very important in the EPS system, which define the maximum angle that the steering wheel can be turned to the left and right in the software. Generally, the left and right limit angles are less than the physical limit angle of the rack, and the left and right limit angles in the EPS are stored in the NVM (Non-Volatile Memory) area of the ECU. When the software is initially run, there is no corresponding left and right limit angle value in the NVM, so the corresponding value needs to be obtained through learning, and the result is stored in the NVM after the vehicle is powered off. The left limit angle θ Lf :

[0133] Step S1: the vehicle speed is less than a threshold V th , the vehicle voltage is normal, and all signals are valid;

[0134] Step S2: the steering wheel angle θ hw is greater than a defined threshold θ min and less than θmax , the absolute value of the steering wheel speed |ω hw |Less than the threshold ω th , hand torque T hw Greater than the threshold T th , and the above judgment conditions are connected using AND operation and maintained for a certain time t, the current steering wheel angle θ hw Assigned to θ Lf This step is to ensure that the rack is in the extreme position and remains stationary for a certain period of time;

[0135] Step S3: If one of the conditions in the above steps is not met at a certain time t0, the system will reset and re-execute the operation for a certain time t.

[0136] Learn the right limit angle θ by following the steps below Ri :

[0137] Step P1: Vehicle speed is less than threshold V th , the vehicle voltage is normal and all signals are valid;

[0138] Step P2: Steering wheel angle θ hw Greater than -θ max and less than -θ min , the absolute value of the steering wheel speed |ω hw |Less than the threshold ω th , hand torque T hw Less than -T th , and the above judgment conditions are connected using AND operation and maintained for a certain time t, the current steering wheel angle θ hw Assigned to θ Ri ;

[0139] Step P3: If one of the conditions in the above steps is not met at a certain time t0, the system will reset and re-execute the operation for a certain time t.

[0140] Get θ Lf and θ Ri Then, continue to judge the absolute difference between the left and right extreme angles |θ Lf |-|θ Ri Is it less than the threshold θ? th If it is not satisfied, the self-learning operation will be re-executed to avoid the random error that causes the left and right limit angles to differ too much and cause the left and right rack travel ranges to be inconsistent. The physical meaning of mathematical symbols is as follows Figure 4 When all the above conditions are met, the flag bit b fg Set from 0 to 1, indicating that the self-learning operation has been completed and both the left and right limits have values, b fg It is crucial for subsequent judgment of the terminal state.

[0141] Through the self-learning module, the software can execute the flow of the limiting module and the alarm module. However, there may be errors in the angle sensor, and the zero return is not completed, so the update learning module is introduced, and the following steps are executed:

[0142] M1: flag b fg is 1, indicating that the self-learning is completed, and the update learning module can be entered;

[0143] M2: θ hw is greater than θ min and less than θ max or θ hw is greater than -θ max and less than -θ min , θ hw is greater than θ Lf or θ hw is less than θ Ri , |ω hw | is less than the threshold value ω th , the above conditions are met and maintained for a certain time t, θ hw is assigned to θ Lf or θ hw is assigned to θ Ri .

[0144] After the learning module, the software learns the left and right limit angles θ Lf and θ Ri , and has the ability to continuously update. After each power-off, the program automatically executes the operation of writing θ Lf , θ Ri , and b fg to the NVM, and after each power-on, the three values are read from the NVM and applied in the software.

[0145] According to the current state of the steering wheel, the end protection is divided into four states, namely disable, normal, entry, and exit. Disable indicates that the current end protection function is in an inactive state, normal indicates that the end protection is activated but has not entered the end travel area, entry indicates that it is in the end travel area and moves towards the end limit position, and exit indicates that it is in the end travel area but moves away from the end limit position. To avoid the transition between entry and exit being too intense and affecting the hand feeling, a low-pass filter is added in the exit stage to make the transition between states smooth.

[0146] The factor limiting module outputs a power reduction factor f, which is in the range [0, 1]. When the state judgment module outputs disable and normal, this module outputs a factor of 1, indicating that no restrictions are placed on the power-assisted motor. When in entry, the power reduction factor is multiplied by the speed factor fv , angle coefficient f a , rotation speed coefficient f ω , related, the calculation formula of the three coefficients is as follows formula (1), (2), (3):

[0147]

[0148] v represents the current vehicle speed, unit: km / h, as the vehicle speed increases, the coefficient decreases, indicating that the assist torque limit is larger at high speed, and the steering wheel limit angle is further limited to protect the driver.

[0149]

[0150] k a indicates the angle-related scaling factor, which is obtained by real vehicle calibration; the end stroke Δθ is related to the vehicle speed, the higher the vehicle speed, the larger Δθ, indicating that the rack will enter the end earlier, and then limit the assist force, embodying the protection of the driver, that is, limit large angle turning at high speed.

[0151]

[0152] f ω decreases with the increase of rotation speed, in the end region, large rotation speed usually means that the rack will contact the limit position earlier, so the assist force coefficient is limited according to the rotation speed.

[0153] The above three coefficients f v , f a , f ω are multiplied by the assist force reduction coefficient f, and act on the motor request torque end of the sum of the basic assist function, the return control function, the damping compensation function and other functions in the EPS. The coefficient is between 0 and 1, and is multiplied by the motor request torque, which realizes the effect of reducing the motor assist torque.

[0154] When in exit, the factor limiting module gradually increases the assist force reduction coefficient f, but cannot be directly increased to 1, because it is still in the end stroke at this time. Therefore, the hand torque is considered as the only input quantity, and the calculation is as follows formula (4):

[0155]

[0156] k ex is a scaling factor, T th_ex is a hand torque threshold, both of which are obtained by real vehicle calibration. When the hand torque |T hw | is greater than a certain threshold T th_ex , it is considered that the rack will soon leave the end region, and the exit state changes to the normal state. When the hand torque |T hw | is less than T th_exWhen , f is quadratically related to the hand torque, which represents the limitation of the assist motor and adjusts the output change rate through the gain factor.

[0157] Furthermore, consider a working condition where frequent commutation at the end of the stroke causes constant switching between the entry and exit states, which in turn affects the consistency of the power reduction coefficient f, leading to significant fluctuations in the power assist motor output, ultimately affecting the hand. Therefore, a low-pass filter is added to the output of the factor limiting module to limit large frequency fluctuations.

[0158] Within the rack end travel, relying solely on the factor limiting module to output the power reduction coefficient f will result in a stiff feel. Without a sense of cushioning, the driver will experience a tactile impact at the end when the hand torque is large. This may also generate noise, affecting the driving experience. Based on this, we propose applying a reverse torque within the end travel. This reverse torque is related to the power assist motor speed, hand torque, and angle, and is calculated using the following formula (5):

[0159]

[0160] ω m Indicates the power assist motor speed in ° / s, k T Represents the gain factor related to the hand torque. dmp As the rack approaches the end limit position θ Lf and θ Ri , its value increases linearly, and as the power assist motor speed |ω m | gradually increases with the increase of k T Calculated by the following formula (6):

[0161]

[0162] k is the scaling factor used to limit T dmp The output level, T dmp If it is too small, the damping effect of the reverse torque will be lost. dmp If it is too large, it will conflict with functions such as basic power assistance and may bring certain dangers. Therefore, the value range of k needs to be calibrated in the actual vehicle.

[0163] The reverse torque module is added to the motor torque request terminal and has the opposite sign to the basic assist. It will only output in the entry and exit states, and output 0 in the other two states. This ensures that the normal output of the motor in the non-terminal range is not affected. The relationship between the assist coefficient and reverse torque and other functions in EPS is as follows: Figure 5 shown.

[0164] In some embodiments, an alarm module is added to the system to remind the driver of the current terminal status.hw = θ Lf - Δθ or θ hw = θ Ri + Δθ, display "entering end" on the vehicle's center screen and maintain for a certain period. When the distance to the end limit position is 5°, i.e. the steering wheel angle θ hw = θ Lf - 5 or θ hw = θ Ri + 5, the center screen displays "reached end, be careful" and a prompt sound is emitted and maintained for a certain time. Through this method, the risk of the driver colliding with the end of the machine is further reduced on the basis of software limitation, the steering system is protected, and the service life is increased.

[0165] Some embodiments of the present application can achieve the following technical effects:

[0166] The calculation process of the end limit position θ and 0m is clarified, and a specific self-learning process is given. The strategy for updating learning is proposed to update the left and right limit angle values stored in the NVM in the case of angle sensor failure and non-zero return.

[0167] The end protection is divided into four states, and the vehicle speed coefficient f, the angle coefficient f, and the rotation speed coefficient f, are used to calculate the reduction assistance coefficient in the normal state, and the specific mathematical expression and calculation process are given. For the exit state, the reduction assistance coefficient is calculated according to the current hand torque.

[0168] The concept of applying a separate reverse torque to the motor request torque end is proposed, which is related to the hand torque, the assistance motor rotation speed and the angle, and the specific calculation process is given. The end feel is optimized while the risk of mechanical collision is reduced.

[0169] The concept of adding an alarm module in the end protection is proposed to assist the driver in judging the current rack state, protecting the steering system while increasing the service life.

[0170] In some embodiments, the system realizes hardware integration through the control unit ECU of the EPS and various sensors, the ECU is connected to the TAS sensor, the optical encoder and the CAN bus. The TAS sensor is integrated on the upper end of the steering column to collect the steering wheel angle θ hw and the hand torque T hw in real time at a sampling frequency of 100HZ; the optical encoder is installed on the output shaft of the assistance motor to measure the assistance motor rotation speed ω m with a resolution less than 0.1rpm; the Hall sensor is installed on the four wheels to calculate the vehicle speed v through the wheel speed pulse, and the ECU obtains the vehicle speed data from the CAN bus every 10ms. The steering wheel rotation speed is obtained by converting the assistance motor rotation speed and the worm gear reduction ratio.

[0171] The self-learning module is started at first running, when the vehicle speed is less than a threshold, the voltage is normal and each signal is valid, if the steering wheel angle θ is continuous for a certain time and meets the preset interval, such as the left limit θ Lf The learning ensures 380°≤θ hw ≤500°, T hw ≥3Nm, |ω hw |≤1rad / s, the current θ hw is assigned to the corresponding limit angle. After self-learning is completed, |θ Lf -θ Ri |≤5°, otherwise re-enter self-learning. The update learning module dynamically corrects θ hw and θ Lf when θ is detected to be out of limit, such as θ is continuous for 2s and exceeds the original limit angle by 5° and |ω Ri |≤0.5rad / s. The correction value is written to the 0x1000-0x1003 address segment of NVM after CRC verification.

[0172] The state update module is divided into four states according to the relationship between θ and the end limit angle θ Lf and θ Ri . disable indicates that the system is not activated, normal indicates that θ hw is not in the end Δθ range (such as θ hw ∈[θ Ri , θ Lf ]), entry indicates that θ hw is in the end range and the speed |ω hw | is towards the end limit direction (such as θ hw ∈[θ Lf -Δθ, θ Lf ] and ω hw ≥0), and disable indicates that θ hw is in the end range but θ hw and ω hw have opposite signs (such as θ hw ∈[θ Lf -Δθ, θ Lf ] and ω hw ≤0). The assist force coefficient f is calculated by the product of the vehicle speed coefficient f v , the angle coefficient f a , and the speed coefficient f ω . In the entry state, the value is directly applied, and in the exit state, it is adjusted according to the hand torque T hw . When T hw is greater than T th_exWhen the state switches, the assist force coefficient f returns to 1. The output of the factor limiting module needs to be smoothed by a 2HZ low-pass filter during the state switching. The reverse torque is activated in the entry / exit state, and the direction of action is opposite to the basic assist force.

[0173] The alarm module adopts a hierarchical triggering strategy, and θ hw When entering the end, the central control screen displays an orange flashing icon and runs for 1s, and when approaching the end limit of 2°, a beeping sound (lasting 2s) is emitted and a red "maximum angle!" warning is popped up.

[0174] The software main loop runs at a period of 10ms, including sensor data filtering, state machine updating, torque synthesis and CAN message 0x2A0 sending. When powered off, θ Lf and θ Ri are automatically saved to NVM, and written to the backup sector in abnormality.

[0175] The application provides a rack end protection system based on multi-module cooperation, which acquires steering parameters in real time through a sensor module, accurately acquires left and right limit angles of the rack by combining self-learning and dynamic updating mechanism, divides four protection states based on a state machine, and innovatively introduces a reduction assist coefficient calculation model and a reverse torque generation algorithm, thereby limiting the motor assist while optimizing the end feel. The system realizes human-computer interaction closed loop through an alarm module, effectively reduces the risk of mechanical collision, and solves the problems of hard hand feeling and low learning accuracy in traditional EPS end protection.

[0176] Based on the foregoing embodiments, the application provides a power control device for a steering wheel, which includes units and modules included in the units, and can be realized by a processor of a device carried or communicatively connected by a vehicle. Of course, it can also be realized by a specific logic circuit. In the implementation process, the processor can be a central processing unit (CPU), a microprocessor unit (MPU), a digital signal processor (DSP) or a field programmable gate array (FPGA).

[0177] Figure 6 A schematic diagram of the composition structure of the power control device for the steering wheel provided by the embodiments of the application is shown in Figure 6 The power control device 50 for the steering wheel includes:

[0178] A sensor module 501 is configured to acquire the steering wheel angle, the hand torque, the assist motor speed and the vehicle speed.

[0179] The learning module 502 is configured to input the steering wheel angle, the hand torque, the assist motor speed, and the vehicle speed into the learning module, and obtain a left limit angle and a right limit angle of the steering wheel.

[0180] The limiting module 503 is configured to determine a rack state of the steering wheel according to a numerical relationship between the current steering wheel angle of the steering wheel and the left limit angle and the right limit angle, determine a reduction assist coefficient and a reverse torque based on the rack state, the steering wheel angle, the hand torque, the assist motor speed, and the vehicle speed, and control the assist motor torque output of the steering wheel based on the reduction assist coefficient, and superimpose the reverse torque on the motor torque output.

[0181] In some embodiments, the learning module 502 is further configured to assign the current steering wheel angle to the left limit angle in a case where the vehicle speed is less than a vehicle speed threshold, a vehicle signal is valid, the steering wheel angle is in a first preset angle interval, the hand torque is greater than a first hand torque threshold, and the absolute value of the steering wheel speed is less than a first steering wheel speed threshold for a duration reaching a first preset time period; and assign the current steering wheel angle to the right limit angle in a case where the vehicle speed is less than the vehicle speed threshold, the vehicle signal is valid, the steering wheel angle is in a second preset angle interval, the hand torque is less than a second hand torque threshold, and the absolute value of the steering wheel speed is less than the first steering wheel speed threshold for a duration reaching a second preset time period, wherein the first preset angle interval and the second angle interval are symmetric with respect to the origin, and the first hand torque threshold and the second hand torque threshold are opposite numbers.

[0182] In some embodiments, the learning module 502 is further configured to update the left limit angle using the current steering wheel angle in a case where the steering wheel angle exceeds the left limit angle for a duration reaching a third preset time period, and the absolute value of the steering wheel speed is less than a second steering wheel speed threshold; and update the right limit angle using the current steering wheel angle in a case where the steering wheel angle exceeds the right limit angle for a duration reaching a fourth preset time period, and the absolute value of the steering wheel speed is less than the second steering wheel speed threshold.

[0183] In some embodiments, the learning module 502 is further configured to re-perform the assignment process of the left limit angle and the right limit angle in a case where the absolute difference between the left limit angle and the right limit angle is greater than a preset angle threshold.

[0184] In some embodiments, the limiting module 503 is further configured to: determine the rack state as a normal state when the steering wheel angle does not enter the end stroke region; determine the rack state as an entering state when the steering wheel angle is in the end stroke region and the steering wheel angle moves towards the end limit position; determine the rack state as an exiting state when the steering wheel angle is in the end stroke region and the steering wheel angle moves away from the end limit position; and determine the rack state as a disabled state when the system meets a disabling condition.

[0185] In some embodiments, the limiting module 503 is further configured to: obtain a first reduction assistance coefficient based on a product of a vehicle speed coefficient, an angle coefficient, and a rotation speed coefficient when the rack state is in the entering state, wherein the vehicle speed coefficient is related to the vehicle speed, the rotation speed coefficient is related to the assistance motor rotation speed, and the angle coefficient is determined by a ratio of the steering wheel angle to the end limit position and a preset scaling factor; determine a second reduction assistance coefficient based on a comparison result of the hand torque and a third hand torque threshold when the rack state is in the exiting state; and output a third reduction assistance coefficient when the rack state is in the normal state or the disabled state, wherein the third reduction assistance coefficient has an effect of not limiting the assistance motor output.

[0186] In some embodiments, the limiting module 503 is further configured to: determine a basic torque according to a linear relationship between the steering wheel angle and the end limit position when the rack state is in the entering state or the exiting state; adjust the basic torque based on a product of an absolute value of the assistance motor rotation speed and a hand torque gain factor to obtain a reverse torque; and set the reverse torque to zero when the rack state is in the disabled state or the normal state.

[0187] In some embodiments, the apparatus further includes an alarm module 504 configured to trigger the alarm module to output a prompt signal when the steering wheel angle enters the end stroke range or approaches the end limit position.

[0188] The embodiments of the present application collect various steering parameters of the steering wheel angle, the hand torque, the assistance motor rotation speed, and the vehicle speed of the vehicle, accurately acquire the left and right limit angles of the rack through the learning module, identify the rack state based on the left and right limit angles, determine the reduction assistance coefficient and the reverse torque for different rack states and steering parameters, so that the steering assistance output torque can be dynamically limited in various working conditions by using the assistance coefficient, the steering assistance limitation can cover various working conditions in the vehicle driving process, and the reverse torque is superimposed on the assistance motor torque output to avoid the end impact touch feeling caused by the large hand torque due to the lack of buffer feeling, thereby optimizing the hand feeling of the steering assistance.

[0189] The description of the above device embodiments is similar to the description of the above method embodiments, and has similar beneficial effects as the method embodiments. In some embodiments, the device provided by the embodiments of the present application has functions or includes modules that can be used to perform the methods described in the above method embodiments. For technical details not disclosed in the device embodiments of the present application, please refer to the description of the method embodiments of the present application for understanding.

[0190] If the technical solutions of the present application involve personal information, the product applying the technical solutions of the present application has clearly informed the personal information processing rules before processing the personal information, and has obtained the personal independent consent. If the technical solutions of the present application involve sensitive personal information, the product applying the technical solutions of the present application has obtained the personal independent consent before processing the sensitive personal information, and at the same time meets the requirement of "explicit consent". For example, at the personal information collection device such as camera, a clear and prominent mark is set to inform that the personal information collection range has been entered, and the personal information will be collected. If the person voluntarily enters the collection range, it is regarded as consent to collect the personal information thereof; or in the case that the personal information processing rules are informed to the person by using obvious mark / information on the device for processing personal information, the personal authorization is obtained by pop-up information or by asking the person to upload the personal information thereof. The personal information processing rules can include personal information processor, personal information processing purpose, processing method, and personal information type.

[0191] It should be noted that, in the embodiments of the present application, if the above-mentioned steering wheel assist control method is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application can be embodied in the form of a software product, which is stored in a storage medium and includes a plurality of instructions for causing a vehicle (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods described in the embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a magnetic disk or an optical disk, and various program code storage media. Thus, the embodiments of the present application are not limited to any specific hardware, software or firmware, or any combination of hardware, software and firmware.

[0192] The embodiments of the present application provide a vehicle, which includes a steering wheel, an assist motor, a memory and a processor, the memory stores a computer program capable of running on the processor, and the processor implements part or all of the steps in the above method when executing the program.

[0193] The present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements some or all of the steps in the above method. The computer-readable storage medium may be transient or non-transient.

[0194] An embodiment of the present application provides a computer program, comprising a computer-readable code. When the computer-readable code runs in a vehicle, a processor in the vehicle executes some or all of the steps for implementing the above method.

[0195] An embodiment of the present application provides a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program, and when the computer program is read and executed by a computer, implements some or all of the steps in the above method. The computer program product can be implemented specifically by hardware, software, or a combination thereof. In some embodiments, the computer program product is embodied as a computer storage medium. In other embodiments, the computer program product is embodied as a software product, such as a software development kit (SDK), etc.

[0196] It should be noted that the descriptions of the various embodiments above tend to emphasize the differences between the various embodiments, and their similarities or similarities can be referenced to each other. The descriptions of the above device, storage medium, computer program, and computer program product embodiments are similar to the descriptions of the above method embodiments and have similar beneficial effects as the method embodiments. For technical details not disclosed in the embodiments of the device, storage medium, computer program, and computer program product of this application, please refer to the description of the method embodiments of this application for understanding.

[0197] It should be noted that Figure 7 This is a schematic diagram of a hardware entity of a vehicle in an embodiment of the present application, such as Figure 7 As shown, the hardware entity of the vehicle 700 includes: one or more processors 701, a communication interface 702 and a memory 703, wherein:

[0198] Processor 701 generally controls the overall operation of vehicle 700 .

[0199] The communication interface 702 enables the vehicle to communicate with other terminals or servers through the network.

[0200] The memory 703 is configured to store instructions and applications executable by the processor 701, and can also cache data to be processed by the processor 701 and modules in the vehicle 700 (for example, image data, audio data, voice communication data and video communication data) to be processed or having been processed, and can be implemented by a FLASH or a random access memory (RAM). The processor 701, the communication interface 702 and the memory 703 can perform data transmission through the bus 704. It is to be noted that the vehicle can include a plurality of processors 701, and each processor 701 can perform data interaction through an aggregate communication mode such as all-to-all, allgather or allreduce. The processor 701 can be a central processing unit (CPU), a graphics processing unit (GPU), a neural-network processing units (NPU), a tensor processing unit (TPU), a data processing units (DPU), an accelerated processing unit (APU), a floating processing units (FPU) or an application-specific integrated circuit (ASIC), etc. The processor can also be a single-core processor or a multi-core processor. The processor can be a combination of a CPU and a hardware chip. The hardware chip can be an ASIC, a PLD or a combination thereof. The PLD can be a complex programmable logic device (CPLD), an FPGA, a generic array logic (GAL) or any combination thereof. The processor can also be implemented by a logic device with built-in processing logic, such as an FPGA or a digital signal processor (DSP), etc.

[0201] It is to be noted that the vehicle can include a plurality of processors 701, and each processor 701 can perform data interaction through an aggregate communication mode such as all-to-all, allgather or allreduce. The processor 701 can be a central processing unit (CPU), a graphics processing unit (GPU), a neural-network processing units (NPU), a tensor processing unit (TPU), a data processing units (DPU), an accelerated processing unit (APU), a floating processing units (FPU) or an application-specific integrated circuit (ASIC), etc. The processor can also be a single-core processor or a multi-core processor. The processor can be a combination of a CPU and a hardware chip. The hardware chip can be an ASIC, a PLD or a combination thereof. The PLD can be a complex programmable logic device (CPLD), an FPGA, a generic array logic (GAL) or any combination thereof. The processor can also be implemented by a logic device with built-in processing logic, such as an FPGA or a digital signal processor (DSP), etc.

[0202] The communication interface 702 can be a wired interface or a wireless interface, for communicating with other modules or devices. The wired interface can be an Ethernet interface, a local interconnect network (LIN), etc. The wireless interface can be a cellular network interface or a wireless local area network interface, etc.

[0203] The memory 703 can be a non-volatile memory, for example, a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically EPROM (EEPROM), or a flash memory. The memory 703 can also be a volatile memory, which can be a random access memory (RAM) used as an external cache. By way of example, and not limitation, many forms of RAM can be used, for example, a static RAM (SRAM), a dynamic RAM (DRAM), a synchronous DRAM (SDRAM), a double data rate SDRAM (DDR SDRAM), an enhanced SDRAM (ESDRAM), a synchlink DRAM (SLDRAM), and a direct rambus RAM (DRRAM), a direct rambus dynamic RAM (DRDRAM), and a rambus DRAM (RDRAM).

[0204] The bus 704 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc.

[0205] It should be understood that every feature, structure, or characteristic described in relation to one embodiment is applicable to at least one other embodiment. Therefore, the appearance of the phrase "in one embodiment" or "in an embodiment" in various places throughout the specification is not necessarily referring to the same embodiment. Furthermore, various features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that the sequence of steps / processes in various embodiments of the present application does not mean the order of execution, the execution order of the steps / processes should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The above sequence number of the embodiments of the present application is only for description, not representing the pros and cons of the embodiments.

[0206] It should be understood that the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0207] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The above-described device embodiments are only illustrative, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed components can be through some interface, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0208] The units described above as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units; they can be located in one place or distributed on multiple network units; some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0209] In addition, each functional unit in each embodiment of the present application can be integrated into one processing unit, or each unit can be a unit alone, or two or more units can be integrated into one unit; the integrated unit can be realized in the form of hardware or hardware plus software functional unit.

[0210] Those skilled in the art can understand that all or part of the steps of the above-mentioned method embodiments can be completed by program instruction related hardware, and the foregoing program can be stored in a computer readable storage medium, and the program executes the steps of the above-mentioned method embodiments when executed; and the foregoing storage medium includes a mobile storage device, a read only memory (ROM), a magnetic disc or an optical disc and various storage medium capable of storing program codes.

[0211] Alternatively, the integrated units of the present application can be stored in a computer readable storage medium if they are realized in the form of software function modules and sold or used as independent products. Based on such understanding, the technical solutions of the present application or the parts that make contributions to the related art can be embodied in the form of software products, and the computer software products are stored in a storage medium, including a plurality of instructions for making a vehicle-mounted or connected electronic device execute all or part of the methods described in the embodiments of the present application. The foregoing storage medium includes a mobile storage device, a ROM, a magnetic disc or an optical disc and various storage medium capable of storing program codes.

[0212] The above is only an embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application.

Claims

1. A method for controlling a steering wheel power assist, characterized in that: The method comprises: Obtain steering wheel angle, hand torque, power assist motor speed and vehicle speed; Inputting the steering wheel angle, the hand torque, the power-assist motor speed, and the vehicle speed into a learning module to obtain the left limit angle and the right limit angle of the steering wheel; determining a rack state of the steering wheel according to a numerical relationship between a current steering wheel angle of the steering wheel and the left limit angle and the right limit angle; Determining a power reduction coefficient and a reverse torque based on the rack state, the steering wheel angle, the hand torque, the power assist motor speed, and the vehicle speed; The power assist motor torque output of the steering wheel is controlled based on the power assist reduction coefficient, and the reverse torque is superimposed on the motor torque output.

2. The method according to claim 1, characterized in that The step of inputting the steering wheel angle, the hand torque, the power-assist motor speed, and the vehicle speed into a learning module to obtain the left limit angle and the right limit angle of the steering wheel includes: When the vehicle speed is less than the vehicle speed threshold, the vehicle signal is valid, the steering wheel angle is within a first preset angle range, the hand torque is greater than the first hand torque threshold, and the duration of the steering wheel speed absolute value being less than the first steering wheel speed threshold reaches a first preset time period, assigning the current steering wheel angle to the left limit angle; When the vehicle speed is less than the vehicle speed threshold, the vehicle signal is valid, the steering wheel angle is in the second preset angle range, the hand torque is less than the second hand torque threshold, and the duration period during which the absolute value of the steering wheel speed is less than the first steering wheel speed threshold reaches the second preset time period, the current steering wheel angle is assigned to the right limit angle, wherein the first preset angle range and the second angle range are symmetrical compared to the origin, and the first hand torque threshold and the second hand torque threshold are opposite numbers.

3. The method according to claim 2, characterized in that After inputting the steering wheel angle, the hand torque, the power-assist motor speed, and the vehicle speed into the learning module to obtain the left limit angle and the right limit angle of the steering wheel, the method further includes: When the duration of the steering wheel angle exceeding the left limit angle reaches a third preset time period and the absolute value of the steering wheel speed is less than a second steering wheel speed threshold, updating the left limit angle using the current steering wheel angle; When the duration of the steering wheel angle exceeding the right limit angle reaches a fourth preset time period and the absolute value of the steering wheel speed is less than a second steering wheel speed threshold, the right limit angle is updated using the current steering wheel angle.

4. The method according to claim 3, characterized in that The method further comprises: When the absolute difference between the left limit angle and the right limit angle is greater than a preset angle threshold, the process of assigning the left limit angle and the right limit angle is re-executed.

5. The method according to any one of claims 1 to 4, characterized in that The determining the rack state of the steering wheel according to the numerical relationship between the current steering wheel angle of the steering wheel and the left limit angle and the right limit angle includes: When the steering wheel angle does not enter the end travel region, the rack state is determined to be a normal state; determining the rack state as an entry state when the steering wheel angle is within the end travel region and the steering wheel angle moves toward an end limit position; determining the rack state as an exit state when the steering wheel angle is within the end travel region and the steering wheel angle moves away from the end limit position; When the system meets the disabling condition, the rack state is determined to be a disabling state.

6. The method according to claim 5, characterized in that The power reduction coefficient is obtained by the following steps: When the rack state is in the entry state, obtaining a first power reduction coefficient based on the product of a vehicle speed coefficient, an angle coefficient, and a rotational speed coefficient, wherein the vehicle speed coefficient is related to the vehicle speed, the rotational speed coefficient is related to the power assist motor rotational speed, and the angle coefficient is determined by a ratio of the steering wheel angle to the end and a preset scaling factor; When the rack state is in the exit state, determining a second power reduction coefficient based on a comparison result of the hand torque and a third hand torque threshold; When the rack state is in the normal state or the disabled state, a third power reduction coefficient is output, and the effect of the third power reduction coefficient is not to limit the output of the power assist motor.

7. The method according to claim 5, characterized in that The reverse torque is obtained by the following steps: When the rack state is in the entering state or the exiting state, determining a basic torque according to a linear relationship between the steering wheel angle and the end limit position; The basic torque is adjusted based on the product of the absolute value of the power-assisting motor speed and the hand torque gain factor to obtain a reverse torque; When the rack state is in the disabled state or the normal state, the reverse torque is set to a zero value.

8. A power steering control device for a steering wheel, characterized in that: include: Sensor module, used to obtain steering wheel angle, hand torque, power steering motor speed and vehicle speed; a learning module, configured to input the steering wheel angle, the hand torque, the power-assist motor speed, and the vehicle speed into the learning module to obtain a left limit angle and a right limit angle of the steering wheel; a limiting module, configured to determine a state of the steering wheel rack based on a numerical relationship between a current steering wheel angle and the left limit angle and the right limit angle; and determine a power reduction coefficient and a reverse torque based on the rack state, the steering wheel angle, the hand torque, the power assist motor speed, and the vehicle speed; The power assist motor torque output of the steering wheel is controlled based on the power assist reduction coefficient, and the reverse torque is superimposed on the motor torque output.

9. A vehicle, characterized in that: It includes a steering wheel, a power-assist motor, a memory, and a processor, among which: The power-assist motor is used to output power-assist torque to the rack of the steering wheel; The memory stores a computer program that can be run on the processor, and when the processor executes the program, the steps of the steering wheel power assistance control method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the steering wheel power assistance control method according to any one of claims 1 to 7 are implemented.

11. A computer program product comprising a non-transitory computer-readable storage medium storing a computer program, wherein: When the computer program is read and executed by a computer, the steps of the steering wheel power assistance control method according to any one of claims 1 to 7 are implemented.

Images