Method and device for debugging steering return of electric power steering system

Abstract

The present application relates to EPS steering calibration technical field, especially in kind of electric power steering system's steering return debugging method and device, wherein, method includes: to target vehicle low speed working condition steering, intermediate position steering and big steering, to establish return coefficient-hand torque curve, lateral acceleration-hand torque curve and steering wheel angle-return coefficient curve;To lateral acceleration-hand torque curve return torque analysis, to get return torque state;According to return torque state to return coefficient-hand torque curve adjustment, to complete electric power steering system's return torque debugging;To steering wheel angle-return coefficient curve return speed analysis, to determine return speed state;According to return speed state to return coefficient-hand torque curve adjustment, to complete electric power steering system's return speed debugging. Thus, it solves how to steer calibration electric power steering system, to reach the optimal steering feel problem.

Description

Technical Field

[0001] This invention relates to the field of EPS steering adjustment technology, and in particular to a steering return adjustment method and device for an electric power steering system. Background Technology

[0002] The steering system controls the car's direction according to the driver's intentions, playing a crucial role in driving safety. It's the most important channel for feedback from the vehicle to the driver; its sensitivity determines the driver's most direct feeling about the car. Steering tuning primarily involves calibrating the Electric Power Steering (EPS) system. EPS provides assist torque through an assist motor, reducing the torque required for the driver to turn the steering wheel. By adjusting the steering assist torque, the steering force and return-to-center performance at different speeds are determined, allowing the steering system to better match the driver's driving intentions and provide appropriate road feel in any driving environment. Key elements of EPS steering tuning include assist, return-to-center, and damping; adjusting the return-to-center setting is crucial for achieving excellent steering feel. Summary of the Invention

[0003] This invention provides a steering return adjustment method and apparatus for an electric power steering system, in order to solve the problem of how to adjust the electric power steering system to achieve the optimal steering feel.

[0004] The first aspect of this invention provides a method for adjusting the steering return-to-center of an electric power steering system, comprising the following steps: performing low-speed steering, mid-position steering, and large-angle steering on a target vehicle to establish a return-to-center coefficient-hand torque curve, a lateral acceleration-hand torque curve, and a steering wheel angle-return-to-center coefficient curve; performing a return-to-center torque analysis on the lateral acceleration-hand torque curve to obtain the return-to-center torque state; adjusting the return-to-center coefficient-hand torque curve according to the return-to-center torque state to complete the return-to-center torque adjustment of the electric power steering system; performing a return-to-center speed analysis on the steering wheel angle-return-to-center coefficient curve to determine the return-to-center speed state; and adjusting the return-to-center coefficient-hand torque curve according to the return-to-center speed state to complete the return-to-center speed adjustment of the electric power steering system.

[0005] Optionally, the return torque state includes at least two of the following: strong return torque in the central region, normal return torque in the central region, strong return torque at large turns, and normal return torque at large turns.

[0006] Optionally, the return speed state includes at least one of fast return speed, slow return speed, and normal return speed.

[0007] Optionally, the step of performing a restoring torque analysis on the lateral acceleration-hand torque curve to obtain the restoring torque state includes:

[0008] The steering start torque at different vehicle speeds is obtained from the lateral acceleration-hand torque curve;

[0009] The steering start torque at adjacent vehicle speeds is compared sequentially to obtain multiple comparison results. If any of the multiple comparison results is greater than a preset value, the return torque state is that the return torque in the central region is strong; otherwise, the return torque state is that the return torque in the central region is normal.

[0010] Determine whether there is a torque asymmetry region in the lateral acceleration-hand torque curve. If the torque asymmetry region exists, the return torque state is strong at large turns; otherwise, the return torque state is normal at large turns.

[0011] Optionally, adjusting the return-to-center coefficient-hand torque curve based on the return-to-center torque state to complete the return-to-center torque tuning of the electric power steering system includes:

[0012] When the return torque state is that the return torque in the central region is strong, the return coefficient in the corresponding region of the return coefficient-hand torque curve is reduced until there is no case greater than the preset value in multiple comparison results;

[0013] When the return torque state is characterized by strong return torque at large turns, reduce the hand torque in the corresponding region of the return coefficient-hand torque curve until there is no longer any region of torque asymmetry.

[0014] When the return torque state is normal in the central region or normal at large turning angles, there is no need to adjust the return coefficient-hand torque curve.

[0015] Optionally, adjusting the return-to-center coefficient-hand torque curve based on the return-to-center speed state to complete the return-to-center speed adjustment of the electric power steering system includes:

[0016] When the return speed is fast, reduce the return coefficient and hand torque in the corresponding area of ​​the return coefficient-hand torque curve until the return speed and hand torque meet the target requirements;

[0017] When the return speed is slow, increase the return coefficient and hand torque in the corresponding area of ​​the return coefficient-hand torque curve until the return speed and hand torque meet the target requirements.

[0018] When the return speed is normal, there is no need to adjust the return coefficient-hand torque curve.

[0019] A second aspect of the present invention provides a steering return-to-center adjustment device for an electric power steering system, comprising: a curve establishment module for performing low-speed steering, mid-position steering, and large-angle steering on a target vehicle to establish a return-to-center coefficient-hand torque curve, a lateral acceleration-hand torque curve, and a steering wheel angle-return-to-center coefficient curve; a return-to-center torque analysis module for performing return-to-center torque analysis on the lateral acceleration-hand torque curve to obtain a return-to-center torque state; a return-to-center torque adjustment module for adjusting the return-to-center coefficient-hand torque curve according to the return-to-center torque state to complete the return-to-center torque adjustment of the electric power steering system; a return-to-center speed analysis module for performing return-to-center speed analysis on the steering wheel angle-return-to-center coefficient curve to determine a return-to-center speed state; and a return-to-center speed adjustment module for adjusting the return-to-center coefficient-hand torque curve according to the return-to-center speed state to complete the return-to-center speed adjustment of the electric power steering system.

[0020] A third aspect of the present invention provides a vehicle comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steering return-to-center adjustment method of the electric power steering system as described in the above embodiments.

[0021] A fourth aspect of the present invention provides a computer program product, which, when executed by a processor, implements the above-described method for adjusting the steering return of an electric power steering system.

[0022] A fifth aspect of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for adjusting the steering return of an electric power steering system.

[0023] The steering return-to-center adjustment method and apparatus for an electric power steering system proposed in this invention can ensure good vehicle return-to-center performance at various speeds by adjusting the return-to-center torque, reducing safety hazards caused by improper steering wheel operation; by adjusting the return-to-center speed, the return-to-center speed can be flexibly adjusted under different operating conditions, making the steering wheel return-to-center process smoother and more stable, reducing the driver's operational difficulty and fatigue during steering, and improving the driver's confidence and sense of security; by adjusting the return-to-center torque and return-to-center speed respectively, the vehicle's handling performance and stability can be significantly improved, the driving experience optimized, and the safety of the vehicle during driving enhanced. It is also of great significance for improving the overall performance of the electric power steering system and meeting the driver's control needs.

[0024] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0025] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0026] Figure 1 This is a flowchart of a steering return-to-center debugging method for an electric power steering system provided in an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of a return coefficient-hand torque curve provided in an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of a lateral acceleration-hand torque curve provided in an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of a steering wheel angle-return coefficient provided in an embodiment of the present invention;

[0030] Figure 5 This is a block diagram of a steering return-to-center adjustment device for an electric power steering system provided in an embodiment of the present invention;

[0031] Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0032] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0033] The steering return adjustment and apparatus of the electric power steering system according to an embodiment of the present invention are described below with reference to the accompanying drawings.

[0034] Figure 1 This is a schematic flowchart illustrating a steering return-to-center adjustment method for an electric power steering system provided in an embodiment of the present invention.

[0035] like Figure 1 As shown, the steering return-to-center adjustment method for this electric power steering system includes the following steps:

[0036] In step S101, the target vehicle is subjected to low-speed steering, mid-position steering, and large-angle steering respectively, in order to establish the return coefficient-hand torque curve, lateral acceleration-hand torque curve, and steering wheel angle-return coefficient curve.

[0037] In actual implementation, it is necessary to first evaluate the steering return-to-center condition of the target vehicle, as follows:

[0038] like Figure 2 As shown, under low-speed steering conditions, the vehicle was driven at idle speed, 10 km / h, 15 km / h, 20 km / h, and 25 km / h respectively. The steering wheel was slowly and evenly turned to its maximum turning angle. The steering wheel was then released, and the speed of return to center was observed to ensure it matched the steering rhythm. The uniformity of the steering wheel's return speed was also observed. This process collected the hand torque and its corresponding steering system friction torque at each speed, and a return-to-center coefficient-hand torque curve was established based on the hand torque and its corresponding steering system friction torque at each speed.

[0039] like Figure 3 As shown, when turning in the middle position, drive at speeds of 20km / h, 40km / h, 60km / h, 80km / h, 100km / h, 120km / h, and 140km / h respectively, slowly and evenly turn the steering wheel left and right at small angles, with the turning angle not exceeding ±15°, and feel whether the return torque is appropriate and whether the return speed is slow and even (when returning to center, the steering wheel slides on the fingertips). In this way, the hand torque and its corresponding lateral acceleration at each speed are collected, and a lateral acceleration-hand torque curve is established based on the hand torque and its corresponding lateral acceleration at each speed.

[0040] like Figure 4 As shown, under large-angle steering conditions, the vehicle was driven at speeds of 40km / h, 60km / h, 80km / h, 100km / h, and 120km / h, and the steering wheel was slowly and evenly turned left and right at large angles, with a turning angle of ±20 to ±180°. The higher the speed, the smaller the turning angle. The specific angle was judged based on the vehicle's handling stability. The steering wheel was checked to see if the return torque was appropriate, whether the torque decreased too quickly when returning to the center position, and whether the return speed was slow and even. The steering wheel angle and its corresponding steering wheel angle rate were collected at each speed, and a lateral acceleration-hand torque curve was established based on the steering wheel angle and its corresponding steering wheel angle rate at each speed.

[0041] In step S102, the lateral acceleration-hand torque curve is analyzed for the normalizing torque to obtain the normalizing torque state.

[0042] In step S103, the return-centering coefficient-hand torque curve is adjusted according to the return-centering torque state to complete the return-centering torque debugging of the electric power steering system.

[0043] In some embodiments, the return torque state includes at least two of the following: strong return torque in the center region, normal return torque in the center region, strong return torque at large turns, and normal return torque at large turns.

[0044] In actual operation, centering not only affects the naturalness of steering but also the linearity of steering force and the convergence of the steering wheel. Therefore, centering adjustment mainly involves adjusting the centering torque and the centering speed. Adjusting the centering torque first requires determining the trend and range of the centering coefficient-hand torque curve, such as... Figure 2 As shown, the torque corresponding to the first point of the return-to-center coefficient-hand torque curve corresponds to the friction torque of the steering system, and is generally taken as about 0.4 Nm, corresponding to a ordinate coefficient of about 0.95. The curve's circular transition and the tire's lateral stiffness are out of phase, and the maximum hand torque is generally taken as 3.0 Nm, corresponding to a ordinate of 0 to 0.2. Therefore, when returning to center, this data principle must be followed, and the steering force will be basically uniform and linear.

[0045] Based on the above principles, the return torque of the electric power steering system is adjusted. The specific process is as follows:

[0046] The steering start torque at different vehicle speeds is obtained from the lateral acceleration-hand torque curve. The steering start torque at adjacent vehicle speeds is compared sequentially, resulting in multiple comparison results. If any of these results exceeds a preset value, the return torque state is considered strong in the central region. The return coefficient in the corresponding region of the return coefficient-hand torque curve is then reduced until no results exceed the preset value. Conversely, if none of these results exceed the preset value, the return torque state is considered normal in the central region, and no adjustment to the return coefficient-hand torque curve is needed. For example, ... Figure 3 The green circle represents the initial torque required to turn the steering wheel, also known as the steering torque lag value. If, at different vehicle speeds, the value of the lower circle is significantly smaller than that of the upper circle (greater than 0.3 Nm), it indicates that the torque required to return to the center area is strong and needs to be reduced. Figure 2 The self-alignment coefficient corresponds to the middle area of ​​the vehicle, until the feel and Figure 3 The return curve is normal. The hand torque range corresponding to the middle position area of ​​the vehicle is 0-2.8Nm, covering a vehicle speed range of 20-100km / h.

[0047] Furthermore, determine if there is a torque asymmetry region in the lateral acceleration-hand torque curve. If a torque asymmetry region exists, the return torque state is characterized by strong return torque at large turns. Reduce the hand torque in the corresponding region of the return coefficient-hand torque curve until no torque asymmetry region exists. Conversely, if no torque asymmetry region exists, the return torque state is characterized by normal return torque at large turns, and no adjustment to the return coefficient-hand torque curve is needed. For example, if the return torque is strong at large turns (regardless of vehicle speed), that corresponds to... Figure 3The torque in the area marked by the dashed line in the blue box is asymmetrical, with the absolute negative value being too small, requiring adjustment. Figure 2 The corresponding curve around 3.0 Nm on the vertical axis shows a decrease in the torque coefficient in the area indicated by the dashed blue box. The specific adjustment range can be determined by whether there is a pullback sensation when returning to center after a large turn.

[0048] It should be noted that, Figure 2 The more points the curve is divided into, the smoother the steering and return-to-center adjustment will be. It is generally recommended to use 8-10 coordinate points.

[0049] In step S104, the steering wheel angle-return coefficient curve is analyzed to determine the return speed status.

[0050] In step S105, the return coefficient-hand torque curve is adjusted according to the return speed status to complete the return speed debugging of the electric power steering system.

[0051] In some embodiments, the return speed state includes at least one of fast return speed, slow return speed, and normal return speed.

[0052] In actual implementation, after completing the return torque adjustment, the return speed of the electric power steering system is adjusted. The specific process is as follows:

[0053] It should be noted that the return-to-center speed refers to the uniformity of the steering wheel's return-to-center speed, which is divided into normal steering and rapid steering. This embodiment of the invention describes normal steering, with a steering wheel angular velocity of 100–150° / s. The return-to-center problem that occurs with rapid steering can be solved through damping compensation and inertia compensation. For example... Figure 4 As shown, different curves represent the characteristics of the return-to-center speed curve at different vehicle speeds. Generally, the maximum vehicle speed is set to 80 km / h. Above 80 km / h, return-to-center mainly relies on... Figure 2 The centering module and the vehicle's own centering mechanism ensure this.

[0054] First, analyze the return speed of the steering wheel angle-return coefficient curve to determine the return speed state. If the return speed is fast, reduce the return coefficient and hand torque in the corresponding area of ​​the return coefficient-hand torque curve until the return speed and hand torque meet the target requirements. If the return speed is slow, increase the return coefficient and hand torque in the corresponding area of ​​the return coefficient-hand torque curve until the return speed and hand torque meet the target requirements. If the return speed is normal, no adjustment to the return coefficient-hand torque curve is needed. For example, Figure 4As shown by the blue curve, a higher return speed is required for low-speed steering wheel return to center, and a larger return speed coefficient value results in a higher return speed. When adjusting the return speed, different vehicle speeds and steering wheel angles should be evaluated to determine the optimal return speed. If the return speed is insufficient, it needs to be increased; if the return is too fast, the return speed coefficient needs to be decreased. It's important to note that the return speed coefficient primarily affects the steering wheel return speed, but it also influences the steering wheel return torque. Increasing the return speed will correspondingly increase the steering wheel return torque; therefore, it needs to be considered in conjunction with the return speed. Figure 2 The return torque module is comprehensively debugged until the steering wheel return speed and return torque meet the subjective and objective target requirements.

[0055] In summary, the steering return-to-center adjustment method for the electric power steering system proposed in the embodiments of the present invention has the following beneficial effects:

[0056] (1) By adjusting the return torque, it can be ensured that the vehicle can maintain good return performance at various speeds, reducing safety hazards caused by improper steering wheel operation;

[0057] (2) By adjusting the return speed, the return speed can be flexibly adjusted under different working conditions, making the return process of the steering wheel more stable and smooth, reducing the driver's operational difficulty and fatigue during the steering process, and improving the driver's confidence and sense of security.

[0058] (3) By adjusting the return torque and return speed respectively, the vehicle's handling performance and stability can be significantly improved, the driving experience can be optimized, and the safety of the vehicle during driving can be enhanced. It is also of great significance for improving the overall performance of the electric power steering system and meeting the driver's handling needs.

[0059] Next, the steering return adjustment device for the electric power steering system according to an embodiment of the present invention is described with reference to the accompanying drawings.

[0060] Figure 5 This is a block diagram of a steering return adjustment device for an electric power steering system provided in an embodiment of the present invention.

[0061] like Figure 5 As shown, the steering return-to-center adjustment device 50 of the electric power steering system includes: a curve establishment module 501, a return-to-center torque analysis module 502, a return-to-center torque adjustment module 503, a return-to-center speed analysis module 504, and a return-to-center speed adjustment module 505.

[0062] The system comprises three modules: a curve establishment module 501, used to perform low-speed steering, mid-position steering, and large-angle steering on the target vehicle to establish return-to-center coefficient-hand torque curves, lateral acceleration-hand torque curves, and steering wheel angle-return-to-center coefficient curves; a return-to-center torque analysis module 502, used to analyze the return-to-center torque of the lateral acceleration-hand torque curve to obtain the return-to-center torque state; a return-to-center torque adjustment module 503, used to adjust the return-to-center coefficient-hand torque curve based on the return-to-center torque state to complete the return-to-center torque adjustment of the electric power steering system; a return-to-center speed analysis module 504, used to analyze the return-to-center speed of the steering wheel angle-return-to-center coefficient curve to determine the return-to-center speed state; and a return-to-center speed adjustment module 505, used to adjust the return-to-center coefficient-hand torque curve based on the return-to-center speed state to complete the return-to-center speed adjustment of the electric power steering system.

[0063] In some embodiments, the return torque state includes at least two of the following: strong return torque in the center region, normal return torque in the center region, strong return torque at large turns, and normal return torque at large turns.

[0064] In some embodiments, the return speed state includes at least one of fast return speed, slow return speed, and normal return speed.

[0065] In some embodiments, the aligning torque analysis module 502 includes:

[0066] The acquisition sub-unit is used to obtain the steering start torque at different vehicle speeds from the lateral acceleration-hand torque curve;

[0067] The first judgment subunit is used to compare the steering start torque at adjacent vehicle speeds in sequence to obtain multiple comparison results. If any of the multiple comparison results is greater than a preset value, the return torque state is that the return torque in the central area is strong; otherwise, the return torque state is that the return torque in the central area is normal.

[0068] The second judgment subunit is used to determine whether there is a torque asymmetry region in the lateral acceleration-hand torque curve. If there is a torque asymmetry region, the return torque state is strong at large turns; otherwise, the return torque state is normal at large turns.

[0069] In some embodiments, the return torque adjustment module 503 includes:

[0070] Adjust the return coefficient subunit. When the return torque state is that the return torque in the central region is strong, reduce the return coefficient in the corresponding region of the return coefficient-hand torque curve until there are no cases in multiple comparison results that are greater than the preset value.

[0071] The manual torque subunit is adjusted to reduce the manual torque in the corresponding area of ​​the return-to-center coefficient-manual torque curve when the return-to-center torque state is strong at large turns, until there is no torque asymmetry area.

[0072] First, no adjustment of the sub-unit is required. This is used when the return torque is normal in the central region or when the return torque at large angles is normal, without needing to adjust the return coefficient-hand torque curve.

[0073] In some embodiments, the return speed adjustment module 505 includes:

[0074] The first adjustment sub-unit for the return coefficient and hand torque is used to reduce the return coefficient and hand torque in the corresponding area of ​​the return coefficient-hand torque curve when the return speed is fast, until the return speed and hand torque meet the target requirements.

[0075] The second adjustment sub-unit for the return coefficient and hand torque is used to increase the return coefficient and hand torque in the corresponding area of ​​the return coefficient-hand torque curve when the return speed is slow, until the return speed and hand torque meet the target requirements.

[0076] The second no-adjustment subunit is used when the return speed is normal, so that there is no need to adjust the return coefficient-hand torque curve.

[0077] It should be noted that the explanation of the aforementioned embodiment of the steering return adjustment method for the electric power steering system also applies to the steering return adjustment device of the electric power steering system in this embodiment, and will not be repeated here.

[0078] The steering return adjustment device for an electric power steering system according to an embodiment of the present invention has the following beneficial effects:

[0079] (1) By adjusting the return torque, it can be ensured that the vehicle can maintain good return performance at various speeds, reducing safety hazards caused by improper steering wheel operation;

[0080] (2) By adjusting the return speed, the return speed can be flexibly adjusted under different working conditions, making the return process of the steering wheel more stable and smooth, reducing the driver's operational difficulty and fatigue during the steering process, and improving the driver's confidence and sense of security.

[0081] (3) By adjusting the return torque and return speed respectively, the vehicle's handling performance and stability can be significantly improved, the driving experience can be optimized, and the safety of the vehicle during driving can be enhanced. It is also of great significance for improving the overall performance of the electric power steering system and meeting the driver's handling needs.

[0082] Figure 6This is a schematic diagram of a vehicle provided in an embodiment of the present invention. The vehicle may include:

[0083] The memory 601, the processor 602, and the computer program stored on the memory 601 and capable of running on the processor 602.

[0084] When the processor 602 executes the program, it implements the steering return-to-center debugging method of the electric power steering system provided in the above embodiments.

[0085] Furthermore, electronic devices also include:

[0086] Communication interface 603 is used for communication between memory 601 and processor 602.

[0087] The memory 601 is used to store computer programs that can run on the processor 602.

[0088] The memory 601 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0089] If the memory 601, processor 602, and communication interface 603 are implemented independently, then the communication interface 603, memory 601, and processor 602 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of representation, Figure 6 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0090] Optionally, in a specific implementation, if the memory 601, processor 602, and communication interface 603 are integrated on a single chip, then the memory 601, processor 602, and communication interface 603 can communicate with each other through an internal interface.

[0091] Processor 602 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention.

[0092] This invention also provides a computer program product, which, when executed by a processor, implements the above-described method for adjusting the steering return of an electric power steering system.

[0093] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for adjusting the steering return of an electric power steering system.

[0094] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0095] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0096] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0097] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0098] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0099] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0100] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0101] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for adjusting the steering return to center of an electric power steering system, characterized in that, Includes the following steps: The target vehicle was subjected to low-speed steering, mid-position steering, and large-angle steering respectively, in order to establish the return coefficient-hand torque curve, lateral acceleration-hand torque curve, and steering wheel angle-return coefficient curve. A restoring torque analysis is performed on the lateral acceleration-hand torque curve to obtain the restoring torque state, specifically including: The steering start torque at different vehicle speeds is obtained from the lateral acceleration-hand torque curve; The steering start torque at adjacent vehicle speeds is compared sequentially to obtain multiple comparison results. If any of the multiple comparison results is greater than a preset value, the return torque state is that the return torque in the central region is strong; otherwise, the return torque state is that the return torque in the central region is normal. Determine whether there is a torque asymmetry region in the lateral acceleration-hand torque curve. If the torque asymmetry region exists, the return torque state is strong at large turns; otherwise, the return torque state is normal at large turns. The return torque coefficient-hand torque curve is adjusted according to the return torque state to complete the return torque tuning of the electric power steering system, specifically including: When the return torque state is that the return torque in the central region is strong, the return coefficient in the corresponding region of the return coefficient-hand torque curve is reduced until there is no case greater than the preset value in multiple comparison results; When the return torque state is characterized by strong return torque at large turns, reduce the hand torque in the corresponding region of the return coefficient-hand torque curve until there is no region of torque asymmetry. When the return torque state is that the return torque in the central area is normal or the return torque at large turning angles is normal, there is no need to adjust the return coefficient-hand torque curve; Perform a return-to-center speed analysis on the steering wheel angle-return-to-center coefficient curve to determine the return-to-center speed status; The return-to-center coefficient-hand torque curve is adjusted based on the return-to-center speed status to complete the return-to-center speed tuning of the electric power steering system, specifically including: When the return speed is fast, reduce the return coefficient and hand torque in the corresponding area of ​​the return coefficient-hand torque curve until the return speed and hand torque meet the target requirements; When the return speed is slow, increase the return coefficient and hand torque in the corresponding area of ​​the return coefficient-hand torque curve until the return speed and hand torque meet the target requirements. When the return speed is normal, there is no need to adjust the return coefficient-hand torque curve.

2. The steering return-to-center adjustment method for an electric power steering system according to claim 1, characterized in that, The return torque state includes at least two of the following: strong return torque in the central region, normal return torque in the central region, strong return torque at large turns, and normal return torque at large turns.

3. The steering return-to-center adjustment method for an electric power steering system according to claim 1, characterized in that, The return speed status includes at least one of the following: fast return speed, slow return speed, and normal return speed.

4. A steering return-to-center adjustment device for an electric power steering system, characterized in that, include: A curve module is established to perform low-speed steering, mid-position steering, and large-angle steering on the target vehicle to establish the return coefficient-hand torque curve, lateral acceleration-hand torque curve, and steering wheel angle-return coefficient curve. The aligning torque analysis module is used to perform aligning torque analysis on the lateral acceleration-hand torque curve to obtain the aligning torque state, specifically including: The acquisition sub-unit is used to obtain the steering start torque at different vehicle speeds from the lateral acceleration-hand torque curve; The first judgment subunit is used to compare the steering start torque at adjacent vehicle speeds in sequence to obtain multiple comparison results. If any of the multiple comparison results is greater than a preset value, the return torque state is that the return torque in the central area is strong; otherwise, the return torque state is that the return torque in the central area is normal. The second judgment subunit is used to determine whether there is a torque asymmetry region in the lateral acceleration-hand torque curve. If there is a torque asymmetry region, the return torque state is strong at large angles; otherwise, the return torque state is normal at large angles. The return torque adjustment module is used to adjust the return coefficient-hand torque curve according to the return torque state to complete the return torque adjustment of the electric power steering system, specifically including: The adjustment of the return coefficient subunit is used to reduce the return coefficient in the corresponding area of ​​the return coefficient-hand torque curve when the return torque state is strong in the central area, until there are no cases in multiple comparison results that are greater than the preset value. The manual torque subunit is adjusted to reduce the manual torque in the corresponding area of ​​the return-to-center coefficient-manual torque curve when the return-to-center torque state is strong at large turns, until there is no torque asymmetry area. First, no sub-unit needs to be adjusted. This is used when the return torque is normal in the central area or when the return torque at large angles is normal, without needing to adjust the return coefficient-hand torque curve. The return speed analysis module is used to analyze the return speed of the steering wheel angle-return coefficient curve to determine the return speed status. The return-to-center speed adjustment module is used to adjust the return-to-center coefficient-hand torque curve according to the return-to-center speed status, so as to complete the return-to-center speed adjustment of the electric power steering system, specifically including: The first adjustment sub-unit for the return coefficient and hand torque is used to reduce the return coefficient and hand torque in the corresponding area of ​​the return coefficient-hand torque curve when the return speed is fast, until the return speed and hand torque meet the target requirements. The second adjustment sub-unit for the return coefficient and hand torque is used to increase the return coefficient and hand torque in the corresponding area of ​​the return coefficient-hand torque curve when the return speed is slow, until the return speed and hand torque meet the target requirements. The second no-adjustment subunit is used when the return speed is normal, so that there is no need to adjust the return coefficient-hand torque curve.

5. A vehicle, characterized in that, include: The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steering return-to-center adjustment method for an electric power steering system as described in any one of claims 1-3.

6. A computer program product, characterized in that, When the computer program / instruction is executed by the processor, it implements the steering return adjustment method of the electric power steering system according to any one of claims 1-3.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the steering return adjustment method for the electric power steering system as described in any one of claims 1-3.

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