A zero position learning control method and device for a steering system

Abstract

The present application provides a kind of zero position learning control method and device of steering system, and it generates electronic center angle data by obtaining limit angle data of steering system at different limit positions, the limit angle data includes first limit angle data and second limit angle data;Obtain the measured center angle data of steering system at the center position;According to the difference between electronic center angle data and measured center angle data, whether the step of aligning electronic zero point and mechanical zero point is judged to realize the alignment of electronic zero point and mechanical zero point.By the method of the present application, the degree difference of left and right steering wheel after completing the steering angle calibration can be automatically guaranteed within a controllable range by software logic, so as to realize the alignment of electronic zero point and mechanical zero point of steering system, improve product quality, avoid after-sales complaints, and ensure driving safety.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of quality control of vehicle steering system, and particularly relates to a zero position learning control method and device of a steering system. BACKGROUND

[0002] For vehicles equipped with a column-electric power steering (C-EPS) system, the electronic zero point of the steering system and the mechanical zero point of the steering system are currently ensured to be consistent through mechanical processing and assembly line assembly. However, this method cannot overcome the inconsistency between the electronic zero point of the steering system and the mechanical zero point of the steering system caused by mechanical processing and assembly errors. If the difference between the two zero points is too large, it will cause market complaints and even affect driving safety. In order to ensure that the difference between the electronic zero point and the mechanical zero point of the steering system is within an acceptable range, it is necessary to invent a control method that can not only complete the learning of the steering angle, but also overcome the problems caused by the previous mechanical processing or assembly, avoid after-sales complaints, and ensure driving safety.

[0003] The current known learning method cannot overcome the inconsistency between the electronic zero point of the steering system and the mechanical zero point of the steering system caused by mechanical processing or assembly. The present application can overcome the above problems, ensure product quality, reduce after-sales complaints, and improve driving safety. Moreover, the method does not require additional hardware and can be implemented through software logic. SUMMARY

[0004] To solve the above problems, the present application provides a zero position learning control method and device of a steering system, which is suitable for learning the steering angle zero position of a C-EPS. Through this method, the degree difference between left and right steering after completing the steering angle calibration can be automatically ensured to be within a controllable range through software logic, rather than relying on mechanical processing and assembly. The purpose of the present application is achieved through the following technical solutions:

[0005] The present application first provides a steering angle zero position learning control method of a steering system, comprising: obtaining limit steering angle data of the steering system at different limit positions to generate electronic center steering angle data, the limit steering angle data comprising first limit steering angle data and second limit steering angle data; obtaining measured center steering angle data of the steering system at a center position; and determining whether the electronic zero point and the mechanical zero point are aligned according to the difference between the electronic center steering angle data and the measured center steering angle data. The method needs to perform center learning when the steering angle of the steering system is in an uncalibrated state (EPS_SteerWhlAgCalSts=0), and aligns the electronic zero point and the mechanical zero point of the steering system through center learning (i.e. the difference between the electronic zero point and the mechanical zero point is within a set range, and the feedback EPS_SteerWhlAgCalSts=1 is received from the steering system).

[0006] Specifically, the steering angle zero position learning control method of the present application comprises the following steps:

[0007] Step S10-generate electronic center steering angle data, comprising:

[0008] Step S11: control the steering system to run to a first limit position (e.g. the steering wheel is turned to the leftmost or rightmost end), and generate first limit steering angle data A1; preferably, when the steering angle of the steering system is in an uncalibrated state, the steering system determines whether the steering system is in a mechanical limit position (the steering wheel reaches the leftmost or rightmost limit position) according to the torque signal T1 and the action time t1 provided by itself;

[0009] Step S12: control the steering system to run to a second limit position (e.g. the steering wheel is turned to the rightmost or leftmost end, opposite to the first limit position), and generate second limit steering angle data A2 according to the sensor signal;

[0010] Step S13: calculate the electronic center steering angle data γ according to the first limit steering angle data A1 and the second limit steering angle data A2; preferably, the calculation method of the electronic center steering angle data γ is: γ= (A1+A2) / 2;

[0011] Step S20: control the steering system to run to a center position, and generate measured center steering angle data A3 according to the sensor signal; specifically, the steering wheel can be turned to the middle position and leveled, and the leveling of the steering wheel is ensured by the auxiliary tool leveler clamped on the steering wheel, and the measured center steering angle data A3 is generated according to the sensor signal at this time;

[0012] Step S30-generate a zero point alignment judgment result according to the electronic center steering angle data generated in step S10 and the measured center steering angle data obtained in step S20.

[0013] Further, the method of generating the first limit data A1 in step S11 comprises:

[0014] Step S11a: control the steering system to steer to the first direction, and determine whether the first limit position is reached according to the sensor signal;

[0015] Step S11b: when it is determined that the steering system is steered to the first limit position (e.g. the leftmost position or the rightmost position), assign the first limit angle data A1 as A1 = η0; wherein η0 is the original reading of the sensor.

[0016] Further, the method of generating the second limit data A2 in step S12 comprises:

[0017] Step S12a: control the steering system to steer to the second direction, and read the original reading ηi of the sensor at each steering angle position during the steering process;

[0018] Step S12b: determine whether ηi is over the maximum range α of the sensor, if the result is no, continue to measure ηi, if the result is yes, start to measure ηi again from zero; i ;

[0019] Step S12c: determine whether the second limit position (i.e. the leftmost position or the rightmost position of the steering wheel, opposite to the first limit position) is reached according to the sensor signal;

[0020] Step S12d: when it is determined that the steering system is steered to the second limit position, record the final reading η i of the sensor at the second limit position;

[0021] Step S12e: assign the second limit angle data A2 according to the information of step S12b and step S12d:

[0022]

[0023] Further, the method of calculating the ideal electronic center angle data γ according to the first limit angle data A1 and the second limit angle data A2 in step S13 comprises:

[0024] γ = (A1 + A2) / 2;

[0025] Further, the method of generating the measured center angle data A3 in step S20 comprises:

[0026] Step S21: control the steering system to steer from the second limit position to the middle position, and read the original reading η k of the sensor at each steering angle position during the steering process;

[0027] Step S22: determine whether the measured center angle data A3 is reached according to the sensor signal;k whether the maximum range of the sensor is passed, if the result of the judgment is no, then continue to measure k , if the result of the judgment is yes, then measure again from zero k ;

[0028] Step S23: judging whether the steering system reaches the horizontal position according to the sensor signal;

[0029] Step S24: when judging that the steering system runs to the horizontal position, recording the final reading of the sensor at the horizontal position k ;

[0030] Step S25: assigning the measured median steering angle data A3 according to the information of step S22 and step S24:

[0031]

[0032] Further, step S30 includes:

[0033] Step S31: calculating the electronic-mechanical zero position deviation angle θ according to the electronic median steering angle data γ and the measured median steering angle data; specifically, the calculation process of the electronic-mechanical zero position deviation angle θ is that the host computer sends the steering system a steering angle zero position learning instruction, and the steering system performs operation θ = [abs(γ) - abs(A3)] after receiving the zero position learning instruction.

[0034] Step S32: judging whether the electronic-mechanical zero position deviation angle θ is greater than a preset zero position deviation angle threshold β, if the result of the judgment is yes, then outputting a first judgment result; if the result of the judgment is no, then outputting a second judgment result. Specifically, the calculation method of the zero position deviation angle threshold β is: β = Roundup[m × (360 / n), n]; wherein, n is the number of teeth of the spline connected with the steering system and the steering column, and m is a fault tolerance coefficient.

[0035] Further, if θ > β, it indicates that the steering angle zero position learning fails, the system displays that the steering angle zero position learning fails, and outputs a fault code; if θ ≤ β, the steering angle zero position learning succeeds, the system displays that the steering angle zero position learning succeeds, and EPS_SteerWhlAgCalSts = 1.

[0036] The second aspect of the present application is to provide a zero position learning control device of a steering system, which comprises:

[0037] a sensor information receiving module configured to receive a sensor signal, the sensor signal comprising torque information and steering angle data information about the steering system, the steering angle data information comprising second limit steering angle data and measured median steering angle data;

[0038] The steering position confirmation module is configured to determine whether the steering system has reached the first limit position and the second limit position;

[0039] The first limit steering angle assignment module is configured to assign a value to the first limit steering angle data when the steering system reaches the first limit position.

[0040] The calculation module is configured to calculate the electronic median rotation angle data γ based on the first limit rotation angle data A1 and the second limit rotation angle data A2, and to calculate the electronic-mechanical zero-position deviation angle θ based on the electronic median rotation angle data γ and the measured median rotation angle data A3;

[0041] The judgment output module is configured to determine whether the electronic-mechanical zero-position deviation angle θ is greater than the zero-position deviation angle threshold β, and output the judgment result.

[0042] Furthermore, the steering position confirmation module has an extreme position reach signal unit, a timing unit, and a position confirmation unit: the extreme position reach signal unit is configured to trigger the timing unit to start timing when the steering system reaches the first extreme position or the second extreme position; the timing unit is configured to start timing after the timing is triggered, and activate the position confirmation unit after the timing exceeds the time threshold t0; the position confirmation unit is configured to output a steering position confirmation signal.

[0043] The beneficial effects of this invention are as follows:

[0044] 1) The method of the present invention can overcome the problem of inconsistency between the electronic zero point and the mechanical zero point of the steering system by relying on software logic without increasing hardware costs;

[0045] 2) The method of this invention can automatically ensure through software logic that the difference in the degree of turning the steering wheel to the left and right after the turning angle calibration is completed is within a controllable range, thereby achieving the alignment of the electronic zero point and the mechanical zero point of the steering system (first, alignment, and second, receiving system feedback). This can ensure the alignment of the two zero points, improve product quality, avoid after-sales complaints, and ensure driving safety. Attached Figure Description

[0046] To better understand the above and other objects, features, advantages, and functions of the present invention, reference can be made to the embodiments shown in the accompanying drawings. The same reference numerals in the drawings refer to the same parts. Those skilled in the art should understand that the drawings are intended to schematically illustrate preferred embodiments of the invention and do not limit the scope of the invention in any way; the parts in the drawings are not drawn to scale.

[0047] Figure 1 The diagram shown is a flowchart of the method of Embodiment 1 of the present invention;

[0048] Figure 2The diagram shown is a control logic schematic of Embodiment 1 of the present invention;

[0049] Figure 3 The diagram shown is a schematic of the steering system within the expected deviation in Embodiment 2 of the present invention;

[0050] Figure 4 The diagram shown is a schematic of the steering system reaching its limit position within the expected deviation in Embodiment 2 of the present invention;

[0051] Figure 5 The diagram shown is a schematic of the steering system exceeding the expected deviation in Embodiment 2 of the present invention;

[0052] Figure 6 The diagram shown is a schematic of the steering system reaching its limit position when the deviation exceeds the expected value in Embodiment 2 of the present invention;

[0053] Figure 7 The diagram shown is a schematic diagram of the device in Embodiment 3 of the present invention.

[0054] In the diagram: 1. Steering wheel; 2. CEPS steering column; 3. Rack; 4. Right front wheel; 5. Left front wheel; 6. Right outer tie rod; 7. Left outer tie rod; 8. Right adjusting nut; 9. Left adjusting nut; 10. Right inner tie rod; 11. Left inner tie rod; 12. Steering system mechanical zero point; 13. Steering system electronic zero point left limit; 14. Steering system electronic zero point left limit; 15. Steering system left mechanical limit; 16. Steering system right mechanical limit; 2' CEPS steering column; 3' Rack; 4' Right front wheel; 5' Left front wheel; 6' Right outer tie rod; 7' Left outer tie rod; 8' Right adjusting nut; 9' Left adjusting nut; 10' Right inner tie rod; 11' Left inner tie rod; 12' Steering system mechanical zero point; 13' Steering system electronic zero point left limit; 14' Steering system electronic zero point left limit; 15' Steering system left mechanical limit; 16' Steering system right mechanical limit. Detailed Implementation

[0055] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0056] The term "comprising" and its variations as used herein signify open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "one example embodiment" and "one embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0057] In order to at least partially solve one or more of the above-mentioned problems and other potential problems, embodiments of this disclosure propose a steering angle zero-position learning control method for a steering system.

[0058] Example 1:

[0059] This embodiment provides a steering angle zero-point learning control method for a steering system, comprising: acquiring limit steering angle data of the steering system at different limit positions to generate electronic center-point steering angle data, wherein the limit steering angle data includes first limit steering angle data and second limit steering angle data; acquiring measured center-point steering angle data of the steering system at the center position; and determining whether the electronic zero point and mechanical zero point are aligned based on the difference between the electronic center-point steering angle data and the measured center-point steering angle data. This method automatically ensures, through software logic, that the difference in the degree of steering wheel turning left and right is within a controllable range after steering angle calibration, rather than relying on machining and assembly. When the steering system steering angle is in an uncalibrated state (EPS_SteerWhlAgCalSts=0), the steering system needs to perform center-point learning, which involves aligning the electronic zero point and mechanical zero point of the steering system (alignment here means that the difference between the two is within a set range, and feedback from the steering system is received: EPS_SteerWhlAgCalSts=1). By aligning the electronic and mechanical zero points of the steering system using this method (both through alignment and receiving system feedback), we can ensure that both zero points are aligned, thereby improving product quality, avoiding after-sales complaints, and ensuring driving safety.

[0060] For the specific implementation process of this embodiment, please refer to [link / reference]. Figure 1 As shown, the implementation logic of this method is as follows: Figure 2 As shown, in some specific embodiments, the method specifically includes the following process:

[0061] Step S10 - Generate electronic median rotation data, including:

[0062] Step S11: Control the steering system to operate at the first limit position (e.g., the steering wheel is turned to the leftmost or rightmost end), and generate the first limit steering angle data A1; preferably, when the steering system angle is in an uncalibrated state, the steering system determines whether it is at the mechanical limit position (the steering wheel has reached the left or right limit position) based on the torque signal T1 and the action time t1 it provides; this step specifically includes:

[0063] Step S11a: Control the steering system to steer in the first direction, and determine whether the first limit position has been reached based on the sensor signal;

[0064] Step S11b: After determining that the steering system has reached the first limit position (such as the leftmost or rightmost position), assign a value to the first limit angle data A1: A1 = η0. η0 is the original reading of the sensor.

[0065] Step S12: Control the steering system to operate at the second extreme position (e.g., the steering wheel is turned to the far right or far left, opposite to the first extreme position), and generate the second extreme steering angle data A2 based on the sensor signal. In one specific embodiment, the implementation steps of step S12 are as follows:

[0066] Step S12a: Control the steering system to steer in the second direction, and read the raw sensor readings η at each corner position during the steering process. i ;

[0067] Step S12b: Determine η i Check if the sensor has reached its maximum range α. If the result is no, continue measuring η. i If the judgment result is yes, then η is measured again starting from zero. i ;

[0068] Step S12c: Determine whether the steering system has reached the second limit position (i.e., the steering wheel is turned to the leftmost or rightmost position, which is the opposite of the first limit position) based on the sensor signal.

[0069] Step S12d: After determining that the steering system has reached the second limit position, record the final reading η of the sensor at the second limit position. i ;

[0070] Step S12e: Assign a value to the second limit angle data A2 based on the information from steps S12b and S12d:

[0071]

[0072] Step S13: Calculate the electron median rotation angle data γ based on the first limit rotation angle data A1 and the second limit rotation angle data A2; preferably, the electron median rotation angle data γ is calculated as follows: γ = (A1 + A2) / 2;

[0073] Step S20: Control the steering system to the center position, and generate measured center position steering angle data A3 based on the sensor signal. Specifically, the steering wheel can be turned to the center position and leveled. The leveling of the steering wheel is ensured by using a level tool attached to the steering wheel. At this point, the angle reading of the steering angle sensor is the center position steering angle data A3. In one specific implementation, the generation of measured center position steering angle data A3 in step S20 is as follows:

[0074] Step S21: Control the steering system to rotate from the second extreme position to the middle position, and read the original sensor reading η at each corner position during the rotation. k ;

[0075] Step S22: Determine η k If the sensor's maximum range α has been exceeded, and the result is no, continue measuring ηk; if the result is yes, start measuring ηk again from zero. k ;

[0076] Step S23: Determine whether the steering system has reached a level position based on the sensor signals;

[0077] Step S24: After determining that the steering system has reached the horizontal position, record the final reading η of the sensor in the horizontal position. k ;

[0078] Step S25: Assign a value to the measured median rotation angle data A3 based on the information from steps S22 and S24:

[0079]

[0080] Step S30 - Generate a zero-point alignment judgment result based on the electronic median rotation angle data generated in step S10 and the measured median rotation angle data obtained in step S20. This step specifically includes:

[0081] Step S31: Calculate the electronic-mechanical zero-position deviation angle θ based on the electronic center angle data γ and the measured center angle data; specifically, the calculation process of the electronic-mechanical zero-position deviation angle θ is as follows: the host computer sends a steering angle zero-position learning command to the steering system, and the steering system performs the calculation θ=[abs(γ)-abs(A3)] after receiving the zero-position learning command;

[0082] Step S32: Determine whether the electronic-mechanical zero-position deviation angle θ is greater than the preset zero-position deviation angle threshold β. If the determination result is yes, output the first determination result; if the determination result is no, output the second determination result. Specifically, the zero-position deviation angle threshold β is calculated as follows: β = Roundup[m × (360 / n), n]; where n is the number of teeth of the spline connecting the steering system and the steering column, and m is the tolerance coefficient.

[0083] In one specific implementation, if the electromechanical zero-position deviation angle θ > the zero-position deviation angle threshold β, it indicates that the corner zero-position learning has failed, and the system displays that the corner zero-position learning has failed and reports a fault code; if θ ≤ β, the corner zero-position learning is successful, and the system displays that the corner zero-position learning is successful, and EPS_SteerWhlAgCalSts=1.

[0084] The prerequisites and principles for implementing this embodiment are as follows:

[0085] 1) When the steering wheel is turned counterclockwise, the torque sensor reading is positive; when the steering wheel is turned clockwise, the reading is negative (consistent with industry definition).

[0086] 2) When the steering wheel is turned counterclockwise, the sensor angle value is positive; when the steering wheel is turned clockwise, the value is negative (consistent with industry definition).

[0087] 3) The range α of the currently used angle sensor is 1440°;

[0088] This invention is defined as follows:

[0089] 1) The condition for determining when the steering wheel is turned to one extreme position is: abs(T1) is greater than or equal to the defined threshold T0, and t1 is greater than the defined threshold t0. Both conditions must be met simultaneously. The same applies to the other end.

[0090] 2) A1 is directly assigned a value based on the sensor's original reading: A1 = η0;

[0091] 3) A2 is then assigned a value based on the reading from the angle sensor, A2 = η i Or A2 = α - η0 + η i ;

[0092] 4) A3 is also assigned a value based on the reading of the angle sensor, A3=η k Or A3 = α – A2 + η k ;

[0093] 5) The smaller β is, the better, but it should be defined comprehensively based on the mechanical structure connecting the steering column and steering wheel, and the feasibility of industrial production. The definition method in this article is as follows:

[0094] β = Roundup [ mX(360 / n), 0 ], where n is the number of teeth on the spline connecting the steering wheel and the steering column, and m is the tolerance coefficient given in conjunction with industrial production.

[0095] It should be noted that A1 is the sensor's raw reading, while A2 and A3 are the readings after processing and calculation. Currently, most sensors have a measurement range of 1440°.

[0096] In some specific examples, the failure to learn the zero-position corner is mainly due to errors in the production process. Adding the functionality (method) described in this paper can detect these errors, preventing the vehicle from leaving the production line without rework. Without this patented functionality, such errors in production would go undetected, leading to the vehicle being taken off the line directly, causing the problem mentioned in this patent. Considering the actual situation on the production line, the current causes are primarily due to:

[0097] 1) Problems with the steering column marking equipment (the chance of equipment malfunction sometimes occurs);

[0098] 2) The steering wheel and steering column should be aligned (this can easily cause problems if the person is too close to the steering wheel).

[0099] Basically, first check cause 2). If 2) is confirmed to be without problems, then check 1). The problem should be solved.

[0100] Example 2:

[0101] The implementation principle of this embodiment is the same as that in Embodiment 1. This embodiment provides an application practice of the zero-position learning control method of this application in conjunction with specific changes in the vehicle steering system. Figure 3 and Figure 4 The example shown is one that has no errors in production and can be taken off the production line after being judged by the method of this application; Figure 5 and Figure 6 These are examples of problems identified using the methods described in this application, requiring rework.

[0102] As shown in the figure, a large difference in the left and right wheel angles or a large difference in the left and right turning radii is the same thing. This is reflected in the detectable quantity in this patent as θ = abs [abs(γ) - abs(A3)]. By judging the magnitude of θ, we can determine whether the difference in the left and right wheel angles (turning radii) is within an acceptable range. Since absolute symmetry does not exist in industrial production, a β is defined here as the zero-angle threshold, and the calculation method for the β value is also given based on the product parameters.

[0103] exist Figure 3When turning the steering wheel in system mode: δL is the steering wheel angle of steering wheel 1 when turning the steering wheel to the left to its limit; δR is the steering wheel angle of steering wheel 1 when turning the steering wheel to the right to its limit; ΦLI is the steering wheel angle of the left front wheel 5 when turning the steering wheel to the left to its limit; ΦLO is the steering wheel angle of the right front wheel 4 when turning the steering wheel to the left to its limit; ΦRO is the steering wheel angle of the left front wheel 5 when turning the steering wheel to the right to its limit; ΦRI is the steering wheel angle of the right front wheel 4 when turning the steering wheel to the right to its limit.

[0104] exist Figure 5 In system mode, steering wheel angles are as follows: δL' is the steering wheel angle 1' when the steering wheel is turned to the left to its maximum position; δR' is the steering wheel angle 1' when the steering wheel is turned to the right to its maximum position; ΦLI' is the steering wheel angle 5' of the left front wheel when the steering wheel is turned to the left to its maximum position; ΦLO' is the steering wheel angle 4' of the right front wheel when the steering wheel is turned to the left to its maximum position; ΦRO' is the steering wheel angle 5' of the left front wheel when the steering wheel is turned to the right to its maximum position; ΦRI' is the steering wheel angle 4' of the right front wheel when the steering wheel is turned to the right to its maximum position.

[0105] exist Figure 3 and Figure 5 In the middle, the positions of rack 3 and rack 3' are different, the lengths of the right outer tie rod 6 and right outer tie rod 6' that expose the right inner tie rod 10 and right inner tie rod 10' are different, and the lengths of the left outer tie rod 7 and left outer tie rod 7' that expose the left inner tie rod 11 and left inner tie rod 11' are different; everything else is the same.

[0106] for Figure 3 and Figure 4 Here is an example of electronic and mechanical zero-point alignment: the mechanical zero-point 12 of the steering system is located between the left limit 13 and the left limit 14 of the electronic zero-point of the steering system. The difference between the steering wheel angle δL when turning the steering wheel to the left limit position and the steering wheel angle δR when turning the steering wheel to the right limit position is within the design range. The difference between the corresponding wheel angles ΦLI and ΦRI is within the design range. The difference between the turning radius of the vehicle when turning left and right is within the design range, which will not cause after-sales complaints or affect driving safety.

[0107] for Figure 5 and Figure 6 This is an example of a misalignment between the electronic and mechanical zero points: the mechanical zero point 12' of the steering system is located outside the left limit 13' and the left limit 14' of the electronic zero point of the steering system. The difference between the steering wheel angle δL' when turning the steering wheel to the left limit position and the steering wheel angle δR' when turning the steering wheel to the right limit position exceeds the design range. The corresponding difference between the wheel angles ΦLI' and ΦRI' exceeds the design range. The difference between the turning radii of the vehicle when turning left and right exceeds the design range, which will lead to after-sales complaints and worse cases in driving safety.

[0108] To avoid this Worse case scenario, we need to:

[0109] 1) Strictly control production and assembly. Based on the current production situation, even adding more inspection procedures cannot completely eliminate the risks, and it will also lead to an increase in production costs.

[0110] 2) Add an electronic control program to prevent the product from flowing to the next workstation when a Worse case occurs, and prompt that it needs to be returned for repair.

[0111] Obviously, method 2) is economically efficient.

[0112] Example 3:

[0113] This embodiment provides an apparatus for implementing the method of Embodiment 1, comprising:

[0114] The sensor information receiving module is configured to receive sensor signals, the sensor signals including torque information and steering angle data information about the steering system, the steering angle data information including second limit steering angle data and measured median steering angle data;

[0115] The steering position confirmation module is configured to determine whether the steering system has reached the first limit position and the second limit position;

[0116] The first limit steering angle assignment module is configured to assign a value to the first limit steering angle data when the steering system reaches the first limit position.

[0117] The calculation module is configured to calculate the electronic median rotation angle data γ based on the first limit rotation angle data A1 and the second limit rotation angle data A2, and to calculate the electronic-mechanical zero-position deviation angle θ based on the electronic median rotation angle data γ and the measured median rotation angle data A3;

[0118] The judgment output module is configured to determine whether the electronic-mechanical zero-position deviation angle θ is greater than the zero-position deviation angle threshold β, and output the judgment result.

[0119] In a preferred embodiment, the steering position confirmation module has an extreme position reach signal unit, a timing unit, and a position confirmation unit: the extreme position reach signal unit is configured to trigger the timing unit to start timing when the steering system reaches the first extreme position or the second extreme position; the timing unit is configured to start timing after the timing is triggered, and activate the position confirmation unit when the timing t1 exceeds the time threshold t0; the position confirmation unit is configured to output a steering position confirmation signal.

[0120] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention; the dimensions described in the drawings and embodiments are not related to the specific physical object and are not used to limit the protection scope of the present invention. The physical dimensions can be selected and changed according to actual needs.

Claims

1. A zero-position learning control method for a steering system, characterized in that, include: Electronic median steering angle data is generated by acquiring the limit steering angle data of the steering system at different limit positions. The limit steering angle data includes first limit steering angle data and second limit steering angle data. Obtain the measured center position steering angle data of the steering system when it is in the center position; Determine whether the electronic zero point and the mechanical zero point are aligned based on the difference between the electronic median rotation angle data and the measured median rotation angle data; Specifically, the steps include the following: Step S10 - Generate electronic median rotation data, including: Step S11: Control the steering system to run to the first limit position and generate the first limit steering angle data A1; Step S12: Control the steering system to run to the second limit position, and generate the second limit steering angle data A2 based on the sensor signal; Step S13: Calculate the electron midpoint rotation angle γ based on the first limiting rotation angle data A1 and the second limiting rotation angle data A2; Step S20: Control the steering system to the center position and generate measured center angle data A3 based on sensor signals; Step S30 - Generate a zero-point alignment judgment result based on the electronic median rotation data generated in step S10 and the measured median rotation data obtained in step S20.

2. The zero-position learning control method according to claim 1, characterized in that, The method for calculating the electronic median rotation angle γ is: γ = (A1 + A2) / 2.

3. The zero-position learning control method according to claim 2, characterized in that, Step S30 includes: Step S31: Calculate the electronic-mechanical zero-position deviation angle θ based on the electronic median rotation angle data γ and the measured median rotation angle data; Step S32: Determine whether the electronic-mechanical zero-position deviation angle θ is greater than the preset zero-position deviation angle threshold β. If the determination result is yes, output the first determination result; if the determination result is no, output the second determination result.

4. The zero-position learning control method according to claim 3, characterized in that, The calculation method for the electromechanical zero-position deviation angle θ is: θ = [abs(γ) - abs(A3)].

5. The zero-position learning control method according to claim 3, characterized in that, The zero-position deflection threshold β is calculated as follows: β = Roundup[m × (360 / n), n]; where n is the number of teeth of the spline connecting the steering system and the steering column, and m is the tolerance coefficient.

6. The zero-position learning control method according to any one of claims 1 to 5, characterized in that, The method for generating the second limit data A2 in step S12 includes: Step S12a: Control the steering system to steer in the second direction, and read the raw sensor readings ηi at each corner position during the steering process; Step S12b: Determine whether ηi has passed the maximum range α of the sensor. If the determination result is no, continue to measure ηi. If the determination result is yes, start measuring ηi again from zero. Step S12c: Determine whether the steering system has reached the second limit position based on the sensor signal; Step S12d: After determining that the steering system has reached the second limit position, record the final reading ηi of the sensor at the second limit position; Step S12e: Assign a value to the second limit angle data A2 based on the information from steps S12b and S12d: ， Where η0 is the initial reading of the sensor at the first extreme position.

7. The zero-position learning control method according to claim 6, characterized in that, The method for generating the measured median rotation data A3 in step S20 includes: Step S21: Control the steering system to rotate from the second extreme position to the middle position, and read the original sensor reading η at each corner position during the rotation. k ; Step S22: Determine η k Check if the sensor has reached its maximum range α. If the result is no, continue measuring η. k If the judgment result is yes, then η is measured again starting from zero. k ; Step S23: Determine whether the steering system has reached a level position based on the sensor signals; Step S24: After determining that the steering system has reached the horizontal position, record the final reading η of the sensor in the horizontal position. k ; Step S25: Assign a value to the measured median rotation angle data A3 based on the information from steps S22 and S24: 。 8. A zero-position learning control device for a steering system, characterized in that, include: The sensor information receiving module is configured to receive sensor signals, the sensor signals including torque information and steering angle data information about the steering system, the steering angle data information including second limit steering angle data and measured median steering angle data; The steering position confirmation module is configured to determine whether the steering system has reached the first limit position and the second limit position; The first limit steering angle assignment module is configured to assign a value to the first limit steering angle data when the steering system reaches the first limit position. The calculation module is configured to calculate the electronic median rotation angle data γ based on the first limit rotation angle data A1 and the second limit rotation angle data A2, and to calculate the electronic-mechanical zero-position deviation angle θ based on the electronic median rotation angle data γ and the measured median rotation angle data A3; The judgment output module is configured to determine whether the electronic-mechanical zero-position deviation angle θ is greater than the zero-position deviation angle threshold β, and output the judgment result.

9. The zero-position learning control device according to claim 8, characterized in that, The steering position confirmation module includes an extreme position reach signal unit, a timing unit, and a position confirmation unit. The extreme position reach signal unit is configured to trigger the timing unit to start timing when the steering system reaches the first extreme position or the second extreme position; The timing unit is configured to start timing after the timing is triggered, and to activate the position confirmation unit when the timing exceeds the time threshold t0. The position confirmation unit is configured to output a steering position confirmation signal.

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