Torque compensation method, device, medium and vehicle for electric power steering system

Abstract

The application provides a torque compensation method, device, medium and vehicle of an electric power steering system. The torque compensation method comprises: acquiring vehicle parameters, wherein the vehicle parameters comprise steering wheel speed, steering wheel cumulative rotation amount and steering ball temperature; determining a torque compensation coefficient of the electric power steering system based on the vehicle parameters; and compensating a basic output torque of the electric power steering system based on the torque compensation coefficient to output a power assistance torque. The torque compensation method compensates the basic output torque of the electric power steering system based on the steering wheel speed, the steering wheel cumulative rotation amount and the steering ball temperature, so that the driver can more easily complete steering, and the steering comfort of the driver is improved.

Description

Technical Field

[0001] This application relates to the field of electronic power steering technology, and more specifically to a torque compensation method, device, medium, and vehicle for an electric power steering system. Background Technology

[0002] In recent years, Electric Power Steering (EPS) systems have gradually been adopted in many vehicle models both domestically and internationally due to their unparalleled advantages over other power steering systems and their wide applicability. When the driver operates the steering wheel, the EPS system uses a power steering motor as an actuator to provide steering assistance. Its main function is to help the driver drive the car more effortlessly and easily, providing assistance during steering and sufficient return torque during automatic return to center to bring the steering wheel back to the neutral position.

[0003] When a car is kept in low temperatures for an extended period, the grease in some ball joints and inside the steering gear may solidify. In this case, a cold start will result in reduced power steering and return-to-center assist, causing the driver to feel that the steering is heavy and affecting the driver's driving experience. Summary of the Invention

[0004] This application is made in consideration of the above-mentioned problems. This application provides a torque compensation method, device, medium, and vehicle for an electric power steering system, which enables the driver to complete steering more easily and improves the driver's driving comfort.

[0005] According to a first aspect of this application, a torque compensation method for an electric power steering system is provided, the torque compensation method comprising:

[0006] Obtain vehicle parameters, including steering wheel speed, cumulative steering wheel rotation, and steering ball joint temperature;

[0007] The torque compensation coefficient of the electric power steering system is determined based on the vehicle parameters.

[0008] The basic output torque of the electric power steering system is compensated based on the torque compensation coefficient to output assist torque.

[0009] In one embodiment of this application, determining the torque compensation coefficient of the electric power steering system based on the vehicle parameters includes:

[0010] The first torque compensation gain coefficient is determined based on the temperature of the steering ball joint.

[0011] The second torque compensation gain coefficient is determined based on the steering wheel rotation speed;

[0012] The third torque compensation gain coefficient is determined based on the cumulative steering wheel rotation.

[0013] The torque compensation coefficient is obtained based on the first torque compensation gain coefficient, the second torque compensation gain coefficient, and the third torque compensation gain coefficient.

[0014] In one embodiment of this application, the method for obtaining the temperature of the steering ball joint includes:

[0015] The vehicle's engine compartment temperature and the controller temperature of the electric power steering system are obtained.

[0016] The steering ball joint temperature is determined based on the cabin temperature and the controller temperature using a preset prediction algorithm.

[0017] In one embodiment of this application, determining the steering ball joint temperature using a preset prediction algorithm includes:

[0018] Determine the parameters of the prediction system and the measurement system;

[0019] The Kalman gain at the current moment is determined based on the error value of the current cabin temperature relative to the steering ball joint temperature, the measurement system parameters, and the error covariance value of the controller temperature relative to the steering ball joint temperature at the previous moment.

[0020] The predicted value of the steering ball joint temperature at the current moment is obtained based on the steering ball joint temperature at the previous moment and the prediction system parameters.

[0021] The current steering ball joint temperature is obtained based on the current controller temperature, the current Kalman gain, the measurement system parameters, and the predicted steering ball joint temperature.

[0022] In one embodiment of this application, the torque compensation method further includes:

[0023] Obtain the preset target temperature of the steering ball joint;

[0024] When the current temperature of the steering ball joint is lower than the target temperature of the steering ball joint, the steering ball joint of the vehicle is heated based on the target temperature of the steering ball joint until the target temperature of the steering ball joint is reached.

[0025] In one embodiment of this application, the torque compensation method further includes:

[0026] When the temperature of the steering ball joint is equal to or higher than the target temperature of the steering ball joint, compensation for the basic output torque of the electric power steering system is stopped.

[0027] In one embodiment of this application, compensating the basic output torque of the electric power steering system based on the torque compensation coefficient to output assist torque includes:

[0028] The product of the torque compensation coefficient and the basic output torque is used as the compensation torque for the basic output torque;

[0029] The compensation torque is superimposed on the base output torque to control the electric power steering system to output the assist torque.

[0030] According to a second aspect of this application, an electronic device is provided, the electronic device including a memory and a processor, the memory storing a computer program executed by the processor, the computer program, when executed by the processor, causing a device equipped with the processor to perform the torque compensation method of the electric power steering system described above.

[0031] According to a third aspect of this application, a storage medium is provided, on which a computer program is stored, the computer program running on a computer, and the computer program, when running, causes the computer to execute the torque compensation method of the electric power steering system described above.

[0032] According to a fourth aspect of this application, a vehicle is provided, including the aforementioned electronic device or the aforementioned storage medium.

[0033] The torque compensation method for the electric power steering system disclosed in this application compensates for the basic output torque of the electric power steering system based on the steering wheel speed, cumulative steering wheel rotation, and steering ball head temperature. This increases the assist value of the electric power steering system motor, reduces the steering wheel effort, makes it easier for the driver to complete the steering, and improves the driver's driving comfort. Attached Figure Description

[0034] The above and other objects, features, and advantages of the present invention will become more apparent from the more detailed description of the embodiments of the invention in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same parts or steps.

[0035] Figure 1 This is a schematic block diagram of an electronic device used in the torque compensation method of an electric power steering system according to an embodiment of the present invention.

[0036] Figure 2 This is a schematic flowchart of a torque compensation method for an electric power steering system according to an embodiment of this application;

[0037] Figure 3 This is an example diagram of the temperature-compensation torque gain curve according to an embodiment of this application;

[0038] Figure 4 This is an example diagram of the steering wheel speed versus compensation torque gain curve according to an embodiment of this application;

[0039] Figure 5 This is an example diagram of the cumulative steering angle-compensation torque gain curve of a steering wheel according to an embodiment of this application;

[0040] Figure 6 This is a schematic flowchart of a torque compensation method for an electric power steering system according to another embodiment of this application;

[0041] Figure 7 This is a schematic structural diagram of a vehicle according to an embodiment of this application;

[0042] Figure 8 This is a schematic structural diagram of a vehicle according to another embodiment of this application. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the present invention more apparent, exemplary embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of the present invention, and not all of the embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described herein, all other embodiments obtained by those skilled in the art without inventive effort should fall within the protection scope of the present invention.

[0044] To address the issue that when a car is exposed to low temperatures for extended periods, the grease in some ball joints and inside the steering gear may solidify, leading to reduced steering assist and return-to-center assist in existing electric power steering systems during cold starts. This results in a heavy steering feel for the driver, negatively impacting the driving experience. This application proposes a torque compensation method, electronic equipment, medium, and vehicle for an electric power steering system, enabling the driver to steer more easily and improving driving comfort. A detailed description follows.

[0045] First, refer to Figure 1 This describes an example control device 100 for implementing embodiments of the method of the present invention.

[0046] like Figure 1 As shown, the control device 100 includes a processor 110, a memory 120, and a communication interface 130. The processor 110, memory 120, and communication interface 130 can be interconnected and communicate via a communication bus 140 and / or other forms of connection mechanisms (not shown).

[0047] It should be noted that Figure 1 The components and structure of the control device 100 shown are merely exemplary and not limiting; the control device may also have other components and structures as needed.

[0048] Optionally, the communication interface 130 may also include a transmitter and / or a receiver.

[0049] The processor 110 may be a microcontroller unit (MCU), a central processing unit (CPU), a digital signal processor (DSP), a microcontroller, an embedded device, or other processing unit with data processing and / or instruction execution capabilities, and may control other components in the autonomous vehicle system to perform desired functions.

[0050] The memory 120 can be various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM), cache memory, synchronous dynamic random access memory (SDRAM), etc. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may also be stored on the computer-readable storage medium, and the memory 120 can execute the program instructions to implement the torque compensation method of the electric power steering system described in the embodiments of the present invention below.

[0051] Next, refer to Figure 2This application describes a torque compensation method for an electric power steering system according to embodiments of the present application. This torque compensation method can be applied to electric power steering systems, more specifically, to scenarios where the electric power steering system provides insufficient assistance during cold starts of vehicles in low temperatures. The electric power steering system utilizes the power generated by an electric motor to assist the driver in steering operations. The system mainly consists of three parts: a signal sensing device, which may include a torque sensor, a steering angle sensor, and a vehicle speed sensor; a steering assist mechanism, which may include a motor, a clutch, and a reduction gear mechanism; and an electronic control device, such as an Electronic Control Unit (ECU). The electric motor only operates when assistance is needed. When the driver operates the steering wheel, the torque and steering angle sensors generate corresponding voltage signals based on the input torque and steering angle, the vehicle speed sensor detects the vehicle speed signal, and the control unit, based on the voltage and vehicle speed signals, issues commands to control the electric motor to operate, thereby generating the required steering assistance.

[0052] like Figure 2 As shown, the torque compensation method for an electric power steering system provided in this application includes the following steps S210-S230.

[0053] In step S210, vehicle parameters are acquired, including steering wheel speed, cumulative steering wheel rotation, and steering ball joint temperature.

[0054] In this application, the cumulative steering wheel rotation can be obtained by collecting the steering wheel angle signal through an angle sensor.

[0055] Specifically, the cumulative steering wheel rotation includes both the magnitude and direction of the steering angle. When representing this, the angle magnitude is indicated by a numerical value, and the direction by a positive or negative sign. For example, a set direction can be used as positive, and a negative angle indicates the opposite direction.

[0056] In this application, the steering wheel speed can be obtained by differentiating the cumulative steering wheel rotation with respect to time.

[0057] In this application, the temperature of the steering ball joint can be obtained directly by means of direct acquisition, for example, by placing a temperature measuring device at the steering ball joint and directly obtaining the temperature near the steering ball joint at this time through the temperature measuring device; or it can be obtained indirectly by means of the ambient temperature.

[0058] In step S220, the torque compensation coefficient of the electric power steering system is determined based on the vehicle parameters.

[0059] In this application, the torque compensation coefficient of the electric power steering system can be determined based on vehicle parameters by querying the corresponding pre-calibrated torque compensation coefficient table based on the steering wheel speed, cumulative steering wheel rotation, and steering ball head temperature.

[0060] In step S230, the basic output torque of the electric power steering system is compensated based on the torque compensation coefficient to output the power steering torque.

[0061] Specifically, the method of compensating the basic output torque of the electric power steering system based on the torque compensation coefficient is to increase the basic output torque of the electric power steering system based on the torque compensation coefficient.

[0062] Here, the base torque is the torque calculated by the EPS system when the driver turns the steering wheel. The EPS system detects the steering wheel angle and vehicle speed through sensors, sends voltage signals to the electronic control unit, and the electronic control unit calculates the torque based on the steering wheel angle and vehicle speed detected by the sensors.

[0063] The torque compensation method of the electric power steering system in this application compensates for the basic output torque of the electric power steering system based on the steering wheel speed, the cumulative steering wheel rotation, and the steering ball temperature, thereby increasing the assistance value of the electric power steering system motor, reducing the steering wheel hand force, making it easier for the driver to complete the steering, and improving the driver's operating comfort.

[0064] In one embodiment of this application, determining the torque compensation coefficient of the electric power steering system based on vehicle parameters includes:

[0065] The first torque compensation gain coefficient is determined based on the temperature of the steering ball joint.

[0066] The second torque compensation gain coefficient is determined based on the steering wheel rotation speed;

[0067] The third torque compensation gain coefficient is determined based on the cumulative steering wheel rotation.

[0068] The torque compensation coefficient is obtained based on the first torque compensation gain coefficient, the second torque compensation gain coefficient, and the third torque compensation gain coefficient.

[0069] Specifically, based on the steering ball joint temperature, the first torque compensation gain coefficient is obtained by looking up a temperature-compensation torque gain table. The table can be generated based on a pre-calibrated temperature-compensation torque gain curve. Figure 3 This is an example diagram of the temperature-compensation torque gain curve according to an embodiment of this application. The horizontal axis in the diagram is the temperature of the steering ball joint, and the vertical axis is the first torque compensation gain coefficient.

[0070] Specifically, based on the steering wheel rotation speed, the second torque compensation gain coefficient is obtained by looking up the steering wheel rotation speed-compensation torque gain table. The table can be generated based on a pre-calibrated steering wheel rotation speed-compensation torque gain curve. Figure 4This is an example diagram of the steering wheel speed versus compensation torque gain curve according to an embodiment of this application. The horizontal axis in the diagram is the steering wheel speed, and the vertical axis is the second torque compensation gain coefficient.

[0071] Specifically, based on the cumulative steering wheel rotation, the third torque compensation gain coefficient is obtained by looking up the cumulative steering wheel angle-compensation torque gain table. The table can be generated based on a pre-calibrated cumulative steering wheel angle-compensation torque gain curve. Figure 5 This is an example diagram of the cumulative steering wheel angle versus compensation torque gain curve according to an embodiment of this application. The horizontal axis of the diagram is the cumulative steering wheel angle, and the vertical axis is the third torque compensation gain coefficient.

[0072] The torque compensation coefficient is obtained by adding the first torque compensation gain coefficient, the second torque compensation gain coefficient, and the third torque compensation gain coefficient, which is used as the final low-temperature torque compensation coefficient.

[0073] In one embodiment of this application, the method for obtaining the temperature of the steering ball joint includes:

[0074] Obtain the vehicle's engine compartment temperature and the controller temperature of the electric power steering system;

[0075] Based on the cabin temperature and controller temperature, the steering ball joint temperature is determined through a preset prediction algorithm.

[0076] In this embodiment, the controller of the electric power steering system can be an electronic control unit (ECU), a microcontroller unit (MCU), a central processing unit (CPU), a digital signal processor (DSP), a microcontroller, an embedded device, or other processing units with data processing capabilities and / or instruction execution capabilities.

[0077] In this embodiment, the preset algorithm can be a Kalman filter algorithm or a neural network model for prediction. When using a Kalman filter algorithm, determining the steering ball joint temperature through a preset prediction algorithm includes:

[0078] The prediction system parameters and measurement system parameters are determined. In this application, it is assumed that the state value at the previous time step is consistent with the predicted state value at the current time step, so the prediction system parameter is set to 1. It is also assumed that the measured value at the previous time step is consistent with the measured state value at the current time step, so the measurement system parameter is also set to 1.

[0079] The Kalman gain at the current moment is determined based on the error value of the current cabin temperature relative to the steering ball joint temperature, the measurement system parameters, and the error covariance value of the controller temperature relative to the steering ball joint temperature at the previous moment. The calculation formula is as follows:

[0080]

[0081] in, The Kalman gain at the current moment. H For measuring system parameters, R is the error covariance value of the controller temperature relative to the steering ball joint temperature at the previous moment. This represents the error value between the current cabin temperature and the steering ball joint temperature.

[0082] Here, the error value between the current cabin temperature and the steering ball joint temperature is... The calculation method is as follows:

[0083] The predicted error value of the engine room temperature relative to the steering ball joint temperature at the current moment is obtained based on the error value of the previous moment's engine room temperature relative to the steering ball joint temperature, the covariance value of the predicted error value of the current moment's engine room temperature relative to the steering ball joint temperature, and the prediction system parameters. The calculation formula is as follows:

[0084]

[0085] in, Q is the error value between the cabin temperature at the previous moment and the steering ball joint temperature. covariance value, This is the predicted error value of the current cabin temperature relative to the steering ball joint temperature.

[0086] The error value of the current cabin temperature relative to the steering ball joint temperature is obtained based on the predicted error value of the current cabin temperature relative to the steering ball joint temperature, the current Kalman gain, and the measurement system parameters. The calculation formula is as follows:

[0087]

[0088] in, This represents the error value between the current cabin temperature and the steering ball joint temperature. This is the predicted error value of the current cabin temperature relative to the steering ball joint temperature. This represents the Kalman gain at the current moment.

[0089] The predicted value of the steering ball joint temperature at the current moment is obtained based on the previous moment's steering ball joint temperature and the prediction system parameters. The calculation formula is as follows:

[0090]

[0091] Where A represents the prediction system parameters. The temperature of the steering ball joint at the previous moment. This is the predicted temperature of the steering ball joint at the current moment.

[0092] Based on the current controller temperature, the current Kalman gain, and the measurement system parameters, the predicted value of the current steering ball joint temperature is used to obtain the current steering ball joint temperature. The calculation formula is as follows:

[0093]

[0094] in, The current controller temperature. This represents the current temperature of the steering ball joint.

[0095] In this embodiment, it is assumed that the state value at the previous moment is consistent with the predicted state value at the current moment, so Q = 0.3; and it is also assumed that the measured value at the previous moment is consistent with the measured state value at the current moment, so R = 0.7.

[0096] In one embodiment of this application, the torque compensation method further includes:

[0097] Obtain the preset target temperature of the steering ball joint;

[0098] When the current temperature of the steering ball joint is lower than the target temperature of the steering ball joint, the vehicle's steering ball joint is heated based on the target temperature until it reaches the target temperature.

[0099] Specifically, heating can be achieved using a heating device. The temperature of the steering ball joint is compared with a set target temperature, such as 40°C. If the current temperature is lower than the target temperature, the heating device starts working, and the steering ball joint is heated. If the temperature exceeds the target temperature, the heating device stops working.

[0100] Due to the inherent error defects in the compensation amount, a heat source device is installed near the steering ball joint to rapidly heat it to a temperature above the target temperature of the steering ball joint, eliminating the need for additional low-temperature compensation and thus making the power assist more precise. This method avoids systematic errors, improves the performance of the electric power steering system, and enhances driver comfort.

[0101] In one embodiment of this application, the torque compensation method further includes:

[0102] When the temperature of the steering ball joint is equal to or higher than the target temperature of the steering ball joint, compensation for the basic output torque of the electric power steering system is stopped.

[0103] See below Figure 6 This paper describes a torque compensation method for an electric power steering system according to another embodiment of the present application.

[0104] In one embodiment of this application, the torque compensation method for an electric power steering system includes:

[0105] Step 1: First, estimate the temperature of the steering ball joint. For example, the temperature at the steering ball joint can be obtained through Kalman filtering.

[0106] Step 2: Compare the temperature of the steering ball joint with the set threshold, such as 40°C;

[0107] Step 3: If the temperature is below the threshold at this point, the heating device starts working, rotates to the ball head for heating, and returns to Step 1. Specifically, PID control can be used for temperature control.

[0108] If the temperature exceeds the threshold at this point, the process ends. Here, during the heating process, if the temperature exceeds the threshold, the heating device stops working, and all compensation torque calculations are skipped, ending the process.

[0109] Step 4: Look up the table and calculate the torque gain.

[0110] Step 5: Output the compensation torque gain.

[0111] In one embodiment of this application, compensating the basic output torque of the electric power steering system based on a torque compensation coefficient to output assist torque includes:

[0112] The product of the torque compensation coefficient and the basic output torque is used as the compensation torque for the basic output torque;

[0113] The compensation torque is superimposed on the base output torque to control the output assist torque of the electric power steering system.

[0114] This application also provides an electronic device in which a navigation server includes a memory and a processor. The memory stores a computer program that is executed by the processor. When the computer program is executed by the processor, it causes the device equipped with the processor to perform the torque compensation method of the electric power steering system as described in any of the above embodiments.

[0115] This application also provides a storage medium storing a computer program that runs on a computer. When the computer program runs, it causes the computer to execute the torque compensation method of the electric power steering system as described in any of the above embodiments.

[0116] This application also provides a vehicle that includes the aforementioned electronic device or the aforementioned storage medium. Figure 7An exemplary vehicle according to an embodiment of this application is shown, the vehicle including electronic devices. Figure 8 A vehicle according to another embodiment of this application is illustrated, the vehicle including a storage medium.

[0117] Although exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of the invention. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of the invention. All such changes and modifications are intended to be included within the scope of the invention as claimed in the appended claims.

[0118] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0119] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed.

[0120] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0121] Similarly, it should be understood that, in order to streamline the invention and aid in understanding one or more of the various aspects of the invention, features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of the invention. However, this approach should not be construed as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the corresponding claims, its inventive point lies in solving the corresponding technical problem with fewer features than all of those in a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of the invention.

[0122] Those skilled in the art will understand that, apart from the mutual exclusion of features, all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or elements of any method or apparatus so disclosed may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0123] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features but not others included in other embodiments, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments can be used in any combination.

[0124] The various component embodiments of the present invention can be implemented in hardware, or as software modules running on one or more processors, or a combination thereof. Those skilled in the art will understand that microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions of some modules in the article analysis device according to embodiments of the present invention. The present invention can also be implemented as an apparatus program (e.g., a computer program and computer program product) for performing part or all of the methods described herein. Such programs implementing the present invention can be stored on a computer-readable medium or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

[0125] It should be noted that the above embodiments are illustrative of the invention and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

[0126] The above description is merely a specific embodiment of the present invention or an explanation of that embodiment. The scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A torque compensation method for an electric power steering system, characterized in that, The torque compensation method includes: Obtain vehicle parameters, including steering wheel speed, cumulative steering wheel rotation, and steering ball joint temperature; The method for obtaining the steering ball joint temperature includes: obtaining the engine compartment temperature of the vehicle and the controller temperature of the electric power steering system, and determining the steering ball joint temperature based on the engine compartment temperature and the controller temperature using a preset prediction algorithm; The step of determining the steering ball joint temperature using a preset prediction algorithm specifically includes: determining prediction system parameters and measurement system parameters; determining the Kalman gain at the current moment based on the error value of the current cabin temperature relative to the steering ball joint temperature, the measurement system parameters, and the error covariance value of the controller temperature relative to the steering ball joint temperature at the previous moment; obtaining the predicted value of the steering ball joint temperature at the current moment based on the steering ball joint temperature at the previous moment and the prediction system parameters; and obtaining the steering ball joint temperature at the current moment based on the controller temperature at the current moment, the Kalman gain at the current moment, the measurement system parameters, and the predicted value of the steering ball joint temperature at the current moment. The torque compensation coefficient of the electric power steering system is determined based on the vehicle parameters. The basic output torque of the electric power steering system is compensated based on the torque compensation coefficient to output assist torque.

2. The torque compensation method for an electric power steering system as described in claim 1, characterized in that, Determining the torque compensation coefficient of the electric power steering system based on the vehicle parameters includes: The first torque compensation gain coefficient is determined based on the temperature of the steering ball joint. The second torque compensation gain coefficient is determined based on the steering wheel rotation speed; The third torque compensation gain coefficient is determined based on the cumulative steering wheel rotation. The torque compensation coefficient is obtained based on the first torque compensation gain coefficient, the second torque compensation gain coefficient, and the third torque compensation gain coefficient.

3. The torque compensation method for an electric power steering system as described in claim 1, characterized in that, The torque compensation method further includes: Obtain the preset target temperature of the steering ball joint; When the current temperature of the steering ball joint is lower than the target temperature of the steering ball joint, the steering ball joint of the vehicle is heated based on the target temperature of the steering ball joint until the target temperature of the steering ball joint is reached.

4. The torque compensation method for an electric power steering system as described in claim 3, characterized in that, The torque compensation method further includes: When the temperature of the steering ball joint is equal to or higher than the target temperature of the steering ball joint, compensation for the basic output torque of the electric power steering system is stopped.

5. The torque compensation method for an electric power steering system as described in any one of claims 1 to 4, characterized in that, The compensation of the basic output torque of the electric power steering system based on the torque compensation coefficient to output assist torque includes: The product of the torque compensation coefficient and the basic output torque is used as the compensation torque for the basic output torque; The compensation torque is superimposed on the base output torque to control the electric power steering system to output the assist torque.

6. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory storing a computer program executed by the processor, the computer program, when executed by the processor, causing the device on which the processor is mounted to perform the torque compensation method of the electric power steering system as described in any one of claims 1-5.

7. A storage medium, characterized in that, The storage medium stores a computer program that runs on a computer and, when running, causes the computer to perform the torque compensation method for the electric power steering system as described in any one of claims 1-5.

8. A vehicle, characterized in that, Includes the electronic device of claim 6 or the storage medium of claim 7.

Images