A gap determination method, system, electronic device, and program product

Abstract

The application relates to the technical field of torque control of a vehicle, in particular to a gap determination method and system, an electronic device and a program product, the method comprising the following steps: determining N positive torque boundary positions and N reverse torque boundary positions corresponding to the vehicle; N is a positive integer greater than 1; determining a positive zero torque boundary position based on the N positive torque boundary positions, and determining a reverse zero torque boundary position based on the N reverse torque boundary positions; and determining a transmission chain tooth side gap in the vehicle based on the positive zero torque boundary position and the reverse zero torque boundary position. Through the technical scheme provided in the embodiments of the application, the elastic deformation caused by a transmission shaft system and tooth surface contact is eliminated as much as possible, so that the obtained gap is basically a pure mechanical gap, and the offset caused by the change of the gap with the loaded torque, temperature and mechanism stiffness is reduced.

Description

Technical Field

[0001] This application relates to the field of torque control technology for vehicles, and more particularly to a method, system, electronic device, and program product for determining clearance. Background Technology

[0002] Torque zero-crossing control in the electric drive system of new energy vehicles typically requires obtaining the backlash of the transmission chain teeth. This backlash is crucial for rationally planning gear engagement and torque transition strategies during torque commutation, thereby reducing the impact and knocking noise generated when gears switch from one contact side to the other. Therefore, accurate backlash measurement is essential for torque zero-crossing control, making the method of backlash determination of paramount importance.

[0003] In the relevant technical solutions for determining the clearance, the average value of the positional change during the forward and reverse approach to the gear is usually directly used as the clearance, without distinguishing between the pure mechanical clearance on the tooth side and the elastic deformation caused by the transmission shaft system and tooth surface contact, which leads to the determined clearance shifting with changes in loading torque, temperature and mechanism stiffness. Summary of the Invention

[0004] This application provides a clearance determination method, system, electronic device, and program product to reduce elastic deformation caused by transmission shafts, tooth surface contact, etc., thereby achieving a clearance that is essentially a pure mechanical clearance. The specific implementation scheme is as follows: Firstly, this application provides a gap determination method, the method comprising: Determine the N positive torque boundary positions and N negative torque boundary positions corresponding to the vehicle; where N is a positive integer greater than 1. Based on N positive torque boundary positions, determine the positive zero torque boundary position, and based on N negative torque boundary positions, determine the negative zero torque boundary position. The backlash of the transmission chain teeth in the vehicle is determined based on the positive zero torque boundary position and the negative zero torque boundary position.

[0005] Through the above-described embodiments, the positive zero torque boundary position is first determined by N positive torque boundary positions, and the negative zero torque boundary position is determined by N negative torque boundary positions. Then, the gap is determined based on the positive zero torque boundary position and the negative zero torque boundary position, thereby eliminating elastic deformation caused by transmission shaft system, tooth surface contact, etc. as much as possible, so that the obtained gap is basically a pure mechanical gap, thereby reducing the offset of the gap caused by changes in loading torque, temperature and mechanism stiffness.

[0006] In one possible implementation, each of the N positive torque boundary positions and N negative torque boundary positions is determined in the following way: The same torque target value is applied to the vehicle multiple times, and the first torque boundary position is collected multiple times according to the control cycle after each application of the torque target value; after the current application of the torque target value, the torque is controlled to return to zero and wait for a set time before the next application of the torque target value. Stability verification and repeatability consistency verification are performed based on multiple first torque boundary positions; If both the stability check and the repeatability consistency check pass, the final torque boundary position is obtained based on multiple first torque boundary positions.

[0007] Through the above-described embodiments, the same target torque value is applied to the vehicle multiple times to facilitate repeatability and consistency verification. After each application of the target torque value, the first torque boundary position is collected multiple times according to the control cycle to perform stability verification during each application of the target torque value. Only after both the repeatability and consistency verification and the stability verification pass are the final torque boundary position determined. This minimizes the inclusion of unstable tooth surface engagement or accidental measurement errors in the torque boundary position, improving the accuracy of the final torque boundary position and enhancing its reproducibility. This, in turn, contributes to improving the robustness and reproducibility of the clearance determination. Furthermore, after applying the target torque value, before applying the next target torque value, the torque is controlled to return to zero and wait for a set time to allow the drivetrain to release to the next repeatable loading state as much as possible. This minimizes the influence of the current applied target torque value on the next applied target torque value, further improving the accuracy of the final torque boundary position.

[0008] In one possible implementation, the stability check includes: After applying the target torque value, a target array is obtained; wherein, the torque boundary positions contained in the target array are all the first torque boundary positions within the set range; Determine whether the number of second torque boundary positions in the target array reaches a first set number; where the second torque boundary position is the torque boundary position in the target array that satisfies the stability condition; If so, the stability check of the applied torque target value is confirmed to be passed, and the stable torque boundary position of the applied torque target value is determined based on each second torque boundary position in the target array. If not, then the stability verification of the applied torque target value has failed.

[0009] Through the above-described embodiments, the first torque boundary position is only included in the target array when it is within a set range. This largely avoids using invalid torque boundary positions for stability verification, thus improving the accuracy of stability verification. Subsequently, when the number of second torque boundary positions satisfying the stability condition in the target array reaches a set number, it can be determined that the tooth surface is basically locked, and the torque boundary position is basically stable. At this point, the stability verification can be considered passed. After the stability verification is passed, the stable torque boundary position of the applied torque target value is determined based on the second torque boundary positions in the target array. This largely avoids using torque boundary positions that are not yet locked, the machine is still moving, or the signal is abnormal as the final torque boundary position of the applied torque target value, thereby improving the accuracy of the torque boundary position.

[0010] In one possible implementation, the stability condition is that the change between the current torque boundary position and its adjacent torque boundary positions in the target array is less than a first stability threshold, or the change between the current torque boundary position and any torque boundary position in the target array is less than a second stability threshold, or the angular velocity corresponding to the current torque boundary position is within a set range, or the rate of change of the angular velocity is less than a third stability threshold, or the position variance of each torque boundary position in the target array is less than a fourth stability threshold.

[0011] Through the above application embodiments, stability conditions are set by means of the following methods: the change between the current torque boundary position and its adjacent torque boundary positions is less than a stability threshold; or the change between the current torque boundary position and any torque boundary position in the target array is less than a second stability threshold; or the angular velocity corresponding to the current torque boundary position is within a set range and the rate of change of the angular velocity is less than a third stability threshold; or the position variance of each torque boundary position in the target array is less than a fourth stability threshold. This is to accurately determine whether the torque boundary positions in the target array are stable, thereby achieving stability verification.

[0012] In one possible implementation, determining the stable torque boundary position of the applied torque target value based on each second torque boundary position in the target array includes: Determine the average torque boundary position between each second torque boundary position in the target array; The average torque boundary position is taken as the stable torque boundary position of the target torque value applied this time.

[0013] Through the above application embodiments, the average torque boundary position between each second torque boundary position in the target array is used as the stable torque boundary position of the applied torque target value, so as to offset random errors as much as possible, and make the determined stable torque boundary position close to the true torque boundary position of the applied torque target value, thereby improving the accuracy of the stable torque boundary position.

[0014] In one possible implementation, the repeatability check includes: Determine whether the number of stable torque boundary positions obtained after applying the same target torque value to the vehicle multiple times reaches a second preset number; If so, when it is determined that each stable torque boundary position meets the consistency condition, the repeated consistency check is deemed to have passed, and the final torque boundary position is determined based on multiple stable torque boundary positions; wherein, the consistency condition includes that the deviation of each stable torque boundary position is less than the consistency threshold. If not, the duplication consistency check has failed.

[0015] Through the above-described embodiments, it is first determined whether the number of stable torque boundary positions obtained after applying the same torque target value to the vehicle multiple times reaches a second preset number. This allows the determination of the number of times the stability check passes when the same torque target value is applied multiple times. Then, when the number of times the stability check passes reaches the second preset number, it is further determined whether the deviation of each stable torque boundary position is less than a consistency threshold. This is to determine whether the stable torque boundary positions obtained by repeatedly applying the same torque target value are consistent. When the deviation of each stable torque boundary position is less than the consistency threshold, it is determined that the stable torque boundary positions obtained by repeatedly applying the same torque target value are consistent. Only then is the final torque boundary position determined based on each stable torque boundary position. This essentially avoids including single accidental measurement errors in the torque boundary position, thereby further improving the accuracy of the final torque boundary position.

[0016] In one possible implementation, the deviation is the difference between two stable torque boundary positions, then the consistency condition includes that the difference between any two stable torque boundary positions is less than a first consistency threshold; or

[0017] The deviation is the dispersion of each stable torque boundary position; then the consistency condition includes the dispersion being less than the second consistency threshold.

[0018] Through the above application embodiments, consistency conditions are set by means of the difference between any two stable torque boundary positions being less than a first consistency threshold, or the dispersion of each stable torque boundary position being less than a second consistency threshold, so as to accurately determine whether the stable torque boundary positions obtained by applying the same torque target value multiple times are consistent, thereby realizing consistency verification.

[0019] In one possible implementation, the final torque boundary position is determined based on multiple stable torque boundary positions, including: Determine the average stable torque boundary position among multiple stable torque boundary positions; The average stable torque boundary position is taken as the final torque boundary position.

[0020] Through the above-described embodiments, the average stable torque boundary position between various stable torque boundary positions is used as the final torque boundary position when the same torque target value is applied multiple times, so as to offset random errors as much as possible, making the determined final torque boundary position close to the true torque boundary position when the same torque target value is applied multiple times, thereby improving the accuracy of the final torque boundary position.

[0021] In one possible implementation, determining the positive zero torque boundary position based on N positive torque boundary positions and determining the reverse zero torque boundary position based on N negative torque boundary positions includes: Determine whether the N positive torque boundary positions and the N negative torque boundary positions are all within the set position range; If so, then based on the N positive torque boundary positions, determine the positive zero torque boundary position, and based on the N negative torque boundary positions, determine the negative zero torque boundary position.

[0022] Through the above-described embodiments, the positive / reverse zero torque boundary positions are determined only when all N positive torque boundary positions and N negative torque boundary positions are within a set position range. This ensures that the positive and negative zero torque boundary positions are obtained under reasonable positive and negative torque boundary positions, thereby improving their accuracy.

[0023] In one possible implementation, determining the positive zero torque boundary position based on N positive torque boundary positions and determining the reverse zero torque boundary position based on N negative torque boundary positions includes: Based on N positive torque boundary positions, the positive torsional stiffness is determined. Then, based on the positive torsional stiffness, the line segments corresponding to the N positive torque boundary positions are extrapolated to obtain the positive zero torque boundary position corresponding to zero torque. Here, the positive torsional stiffness is the shape parameter of the line segments corresponding to the N positive torque boundary positions; and... Based on the N reverse torque boundary positions, the reverse torsional stiffness is determined. Based on the reverse torsional stiffness, the line segments corresponding to the N reverse torque boundary positions are extrapolated to obtain the reverse zero torque boundary position corresponding to zero torque. Here, the reverse torsional stiffness is the shape parameter of the line segments corresponding to the N reverse torque boundary positions.

[0024] Through the above-described embodiments, the torsional stiffness is obtained from the torque boundary position for both the forward and reverse directions. Then, extrapolation is performed based on the torsional stiffness to obtain the zero torque boundary position corresponding to zero torque. This reduces the computational load of the zero torque boundary position and improves the efficiency of the zero torque boundary position while ensuring its accuracy as much as possible.

[0025] In one possible implementation, determining the backlash of the drive chain teeth in the vehicle based on the positive zero torque boundary position and the negative zero torque boundary position includes: The difference between the positive zero torque boundary position and the negative zero torque boundary position is used as the initial clearance on the transmission chain tooth side in the vehicle. A reasonableness check is performed on the initial gap. If the reasonableness check passes, the initial gap is taken as the gap. The reasonableness check includes: if it is determined that the change between the initial gap and the previous gap in the storage space is less than a set change threshold, then the reasonableness check is determined to pass.

[0026] Through the above-described embodiments, the difference between the positive zero-torque boundary position and the negative zero-torque boundary position is used as the initial clearance on the tooth side of the transmission chain in the vehicle. This further eliminates elastic deformation caused by the transmission shaft system and tooth surface contact as much as possible, making the resulting clearance approximately a pure mechanical clearance and reducing the offset caused by changes in loading torque, temperature, and mechanism stiffness. Subsequently, when the change between the initial clearance and the previous clearance in the storage space is less than a set change threshold, the rationality verification of the initial clearance is determined to be passed. Only then is the initial clearance used as the final clearance, thereby essentially avoiding using a clearance that exceeds the reasonable range as the final clearance and further improving the accuracy of the clearance.

[0027] In one possible implementation, after determining the backlash of the drive chain teeth in the vehicle, the method further includes: Write the gaps and the corresponding learning information into the storage space; When the vehicle is powered on again, the current gap in the storage space is checked for reasonableness. If the current clearance passes the rationality check, the current clearance will be used as the clearance reference value for torque zero-crossing control. If the current gap fails the rationality check, the historical valid gap or default gap in the storage space will be used as the gap reference value for torque zero-crossing control.

[0028] Through the above-described embodiments, the gap and its corresponding learning information (such as time difference, motor oil temperature, etc.) are written into the storage space so that when using the gap later, information such as the motor oil temperature corresponding to that gap can be obtained. Subsequently, when the vehicle is powered on again, only when the current gap in the storage space passes the rationality check is the current gap used as the gap reference value for torque zero-crossing control. If the current gap fails the rationality check, the historical valid gap or default gap in the storage space is used as the gap reference value for torque zero-crossing control. This allows for gap reference management across power-on cycles while largely avoiding the use of unreasonable gaps as gap reference values, thus ensuring the accuracy of the gap reference value as much as possible.

[0029] Secondly, this application also provides a gap determination system, the system comprising: The first determining module is used to determine the N positive torque boundary positions and N negative torque boundary positions corresponding to the vehicle; where N is a positive integer greater than 1. The second determining module is used to determine the positive zero torque boundary position based on N positive torque boundary positions, and to determine the reverse zero torque boundary position based on N reverse torque boundary positions. The processing module is used to determine the backlash of the transmission chain teeth in the vehicle based on the positive zero torque boundary position and the negative zero torque boundary position.

[0030] In one possible implementation, each of the N positive torque boundary positions and N negative torque boundary positions is determined as follows: the same torque target value is applied to the vehicle multiple times, and after each application of the torque target value, the first torque boundary position is collected multiple times according to the control cycle; wherein, after the current application of the torque target value, the torque is controlled to return to zero and a set time is waited before the next application of the torque target value; based on the multiple first torque boundary positions, stability verification and repeatability consistency verification are performed; if it is determined that both stability verification and repeatability consistency verification are passed, the final torque boundary position is obtained based on the multiple first torque boundary positions.

[0031] In one possible implementation, the stability verification includes: after applying the target torque value, obtaining a target array; wherein the torque boundary positions contained in the target array are all first torque boundary positions within a set range; determining whether the number of second torque boundary positions in the target array reaches a first set number; wherein the second torque boundary positions are torque boundary positions in the target array that satisfy the stability condition; if yes, then the stability verification of the applied torque target value is determined to be passed, and based on each second torque boundary position in the target array, the stable torque boundary position of the applied torque target value is determined; if no, then the stability verification of the applied torque target value is determined to be failed.

[0032] In one possible implementation, the stability condition is that the change between the current torque boundary position and its adjacent torque boundary positions in the target array is less than a first stability threshold, or the change between the current torque boundary position and any torque boundary position in the target array is less than a second stability threshold, or the angular velocity corresponding to the current torque boundary position is within a set range, or the rate of change of the angular velocity is less than a third stability threshold, or the position variance of each torque boundary position in the target array is less than a fourth stability threshold.

[0033] In one possible implementation, when the first determining module determines the stable torque boundary position of the target torque value applied this time based on each of the second torque boundary positions in the target array, it is specifically used to determine the average torque boundary position between each of the second torque boundary positions in the target array; and to use the average torque boundary position as the stable torque boundary position of the target torque value applied this time.

[0034] In one possible implementation, the repeatability check includes: determining whether the number of stable torque boundary positions obtained after applying the same torque target value to the vehicle multiple times reaches a second preset number; if yes, when it is determined that each stable torque boundary position meets the consistency condition, the repeatability check is determined to be passed, and the final torque boundary position is determined based on the multiple stable torque boundary positions; wherein, the consistency condition includes that the deviation of each stable torque boundary position is less than a consistency threshold; if no, the repeatability check is determined to be failed.

[0035] In one possible implementation, if the deviation is the difference between two stable torque boundary positions, then the consistency condition includes that the difference between any two stable torque boundary positions is less than a first consistency threshold; or, if the deviation is the dispersion of each stable torque boundary position, then the consistency condition includes that the dispersion is less than a second consistency threshold.

[0036] In one possible implementation, when determining the final torque boundary position based on multiple stable torque boundary positions, the first determining module is specifically used to determine the average stable torque boundary position among the multiple stable torque boundary positions; and to use the average stable torque boundary position as the final torque boundary position.

[0037] In one possible implementation, when the second determining module determines the positive zero torque boundary position based on N positive torque boundary positions and the reverse zero torque boundary position based on N negative torque boundary positions, it is specifically used to determine whether both the N positive torque boundary positions and the N negative torque boundary positions are within a set position range; if so, it determines the positive zero torque boundary position based on the N positive torque boundary positions and the reverse zero torque boundary position based on the N negative torque boundary positions.

[0038] In one possible implementation, when the second determining module determines the positive zero torque boundary position based on N positive torque boundary positions and the reverse zero torque boundary position based on N negative torque boundary positions, it is specifically used to determine the positive torsional stiffness based on the N positive torque boundary positions, and extrapolate the line segments corresponding to the N positive torque boundary positions based on the positive torsional stiffness to obtain the positive zero torque boundary position corresponding to zero torque; wherein, the positive torsional stiffness is the shape parameter of the line segments corresponding to the N positive torque boundary positions; and to determine the reverse torsional stiffness based on the N negative torque boundary positions, and extrapolate the line segments corresponding to the N negative torque boundary positions based on the reverse torsional stiffness to obtain the reverse zero torque boundary position corresponding to zero torque; wherein, the reverse torsional stiffness is the shape parameter of the line segments corresponding to the N negative torque boundary positions.

[0039] In one possible implementation, when the processing module determines the clearance of the transmission chain teeth in the vehicle based on the positive zero torque boundary position and the negative zero torque boundary position, it specifically uses the difference between the positive zero torque boundary position and the negative zero torque boundary position as the initial clearance of the transmission chain teeth in the vehicle; performs a rationality check on the initial clearance; and in response to the rationality check passing, uses the initial clearance as the clearance; wherein, the rationality check includes: if it is determined that the change between the initial clearance and the previous clearance in the storage space is less than a set change threshold, then the rationality check is determined to pass.

[0040] In one possible implementation, after determining the backlash of the transmission chain teeth in the vehicle, the processing module is further used to write the backlash and the corresponding learning information into the storage space; when the vehicle is powered on again, the current backlash in the storage space is checked for reasonableness; if the current backlash passes the reasonableness check, the current backlash is used as the backlash reference value for torque zero-crossing control; if the current backlash fails the reasonableness check, the historical valid backlash or default backlash in the storage space is used as the backlash reference value for torque zero-crossing control.

[0041] Thirdly, this application provides an electronic device, comprising: Memory, used to store computer programs; A processor, when executing a computer program stored in memory, implements the method described in any one of the first aspects.

[0042] Fourthly, this application provides a computer-readable storage medium storing a computer program, the computer program including program instructions, which, when executed by a computer, cause the computer to perform the method described in any one of the first aspects.

[0043] Fifthly, this application provides a computer program product comprising: computer program code, which, when run on a computer, causes the computer to perform the method described in any one of the first aspects.

[0044] For the various aspects of the second to fifth aspects mentioned above, and the technical effects that each aspect may achieve, please refer to the above description of the technical effects that can be achieved for the first aspect or the various possible solutions in the first aspect, which will not be repeated here. Attached Figure Description

[0045] Figure 1 A flowchart illustrating a gap determination method provided in this application embodiment. Figure 1 ; Figure 2 A schematic diagram illustrating the process of determining the torque boundary position as provided in an embodiment of this application; Figure 3 A schematic diagram illustrating the timing relationship between the target torque value and the motor rotor position, provided in an embodiment of this application; Figure 4 A schematic diagram showing the rotor position, target torque value, torsional stiffness, and clearance of the motor provided in the embodiments of this application; Figure 5 A flowchart illustrating the process of determining the gap provided in this application embodiment. Figure 1 ; Figure 6 A flowchart illustrating the process of determining the gap provided in this application embodiment. Figure 2 ; Figure 7 A flowchart illustrating a gap determination method provided in this application embodiment. Figure 2 ; Figure 8 A schematic diagram illustrating the composition of the gap determination system and the control relationships between its units, provided in an embodiment of this application. Figure 9 A schematic diagram of a gap determination system provided in an embodiment of this application; Figure 10 This is a schematic diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than that shown here.

[0047] The terms "first" and "second" in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the term "comprising" and any variations thereof are intended to cover non-exclusive protection. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices. The term "multiple" in this application can mean at least two, for example, two, three, or more, and the embodiments of this application do not impose limitations.

[0048] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of this application, including various details to aid understanding. These embodiments should be considered merely exemplary. Therefore, those skilled in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope of this application. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description. It should be noted that in the embodiments of this application, certain existing industry solutions such as software, components, and models may be mentioned. These should be considered exemplary, intended only to illustrate the feasibility of implementing the technical solutions of this application, and do not imply that the applicant has already used or necessarily used such solutions.

[0049] The acquisition, transmission, storage, and use of data in this application all comply with relevant national laws and regulations.

[0050] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0051] In the relevant technical solutions for determining the clearance, the average value of the positional change during the positive and negative approach to the gear is usually directly used as the clearance value, without distinguishing between the pure mechanical clearance on the tooth side and the elastic deformation caused by the transmission shaft system and tooth surface contact, which leads to the determined clearance shifting with changes in loading torque, temperature and mechanism stiffness.

[0052] Therefore, this application proposes a clearance determination method for use in a clearance determination system, which can be an electric drive system for new energy vehicles, but is not limited to this. The clearance determination system first determines the positive zero torque boundary position using N positive torque boundary positions, and then determines the reverse zero torque boundary position using N reverse torque boundary positions. The clearance is then determined based on these positive and reverse zero torque boundary positions, thereby minimizing elastic deformation caused by the drive shaft system, tooth surface contact, etc., resulting in a clearance that is essentially purely mechanical. This reduces the offset caused by changes in loading torque, temperature, and mechanism stiffness.

[0053] Reference Figure 1 The diagram shown is a flowchart illustrating a gap determination method provided in an embodiment of this application. The method includes: S101, determine the N positive torque boundary positions and N negative torque boundary positions corresponding to the vehicle.

[0054] Before determining the clearance on the transmission chain teeth side of the vehicle, the clearance determination system first determines whether the current environment of the vehicle meets the entry conditions for clearance determination. These entry conditions include at least the vehicle being parked (e.g., vehicle speed is zero, parking mechanism is in a learnable state) and not being powered off. Therefore, clearance determination can be performed at least when the vehicle is parked and not powered off. This allows the system to operate independently of actual driving conditions such as torque crossing zero, high-speed slippage, or drive / brake switching, decoupling clearance determination from normal vehicle operation. This largely avoids interference with the driver's actions caused by clearance determination and helps update clearance data according to operating conditions such as oil temperature throughout the vehicle's lifespan.

[0055] In this embodiment, the admission conditions, in addition to the vehicle being parked and not powered off, may also include no driver request for driving or acceleration, the gear position and high / low voltage power supply status meeting the learning requirements, normal communication between the Vehicle Control Unit (VCU) and the Motor Control Unit (MCU) / Power Electronic Unit (PEU), no faults prohibiting self-learning (such as no motor overheating faults or loose position sensor faults), and the motor oil temperature being within the preset operating temperature window. The requirement that the gear position and high / low voltage power supply status meet the learning requirements means that the vehicle's gear position and power supply status can support the vehicle's movement during the interval determination process; the preset operating temperature window can be calibrated and configured according to specific application scenarios to adapt to different vehicle models and transmission system characteristics.

[0056] Before performing the clearance determination step, the clearance determination system needs to ensure that the vehicle meets each of the aforementioned access conditions. Therefore, once the vehicle meets the access condition, the clearance determination system can automatically begin performing the clearance determination step, thereby achieving automatic clearance determination.

[0057] In another possible implementation, the gap determination system can also be initiated manually by a driver, vehicle maintenance personnel, or calibration personnel via the vehicle's infotainment system, after-sales diagnostic equipment, or engineering calibration tools. In this method, the vehicle also needs to meet certain eligibility criteria.

[0058] In this application example, the gap determination system can determine whether to automatically execute the gap determination steps or manually activate them by setting two states: "Allow automatic self-learning" and "Disable automatic self-learning". For example, when the vehicle system or diagnostic system is set to allow automatic self-learning, the gap determination system can automatically execute the gap determination steps after the vehicle meets the access conditions; when the vehicle system or diagnostic system is set to disable automatic self-learning, the gap determination system can be manually triggered by the driver, vehicle maintenance personnel, or calibration personnel to start executing the gap determination steps, so as to meet the needs of different user preferences, after-sales diagnosis, test verification, or special use scenarios.

[0059] Furthermore, after determining that the vehicle meets the access conditions, the clearance determination system first determines N positive torque boundary positions and N negative torque boundary positions corresponding to the vehicle. Here, N is a positive integer greater than 1. The torque boundary positions can be represented by the motor rotor position, which can be represented by the motor rotor angle. Alternatively, the torque boundary positions can be represented by the resolver angle, encoder angle, rotor angle estimated based on the motor control algorithm, or a combination of half-shaft angles, or wheel end angles, etc., signals that reflect the relative displacement of the transmission chain. However, the data used for clearance calculation should remain continuous, valid, and usable for comparing torque boundary positions during the same learning process (i.e., the same clearance determination process).

[0060] The aforementioned N positive torque boundary positions and N negative torque boundary positions can all be determined using the same method. Taking one torque boundary position from the N positive and N negative torque boundary positions as an example, the process of determining this torque boundary position can be as follows: Figure 2 As shown: The gap determination system first initializes the inner and outer loop counters. For example, the system sets both the inner and outer loop counters to zero. Then, the system applies a target torque value to the vehicle and waits for a first set time. It then acquires the first torque boundary position according to the control cycle and determines whether this position is reasonable. The target torque value is measured in Newton-meters (Nm). The target torque value and the first set time can be calibrated and configured according to specific application scenarios to adapt to different vehicle models, drivetrain stiffness characteristics, and the accuracy of the motor rotor position sensor.

[0061] In this embodiment, the gap determination system can determine whether the first torque boundary position is reasonable or unreasonable by judging whether the first torque position is within a set range. This set range can be calibrated and configured according to specific application scenarios to adapt to different vehicle models, transmission chain stiffness characteristics, and motor rotor position sensor accuracy.

[0062] If the position of the first torque boundary is determined to be outside the set range, the gap determination system can determine that the position of the first torque boundary is unreasonable. In this case, the inner ring counter is incremented by 1.

[0063] If the first torque boundary position is determined to be within the set range, the gap determination system can determine that the first torque boundary position is reasonable and add this reasonable first torque boundary position to the inner loop array (i.e., the target array), while simultaneously incrementing the coordinates of the inner loop array by 1. Therefore, all torque boundary positions in the inner loop array are reasonable first torque boundary positions. Next, the gap determination system determines whether the torque boundary positions in the inner loop array are stable.

[0064] In this embodiment, the gap determination system can determine whether the torque boundary position in the inner loop array is stable by whether the torque boundary position meets the stability condition. For example, if the torque boundary position in the inner loop array meets the stability condition, the torque boundary position is determined to be stable; otherwise, the torque boundary position is determined to be unstable.

[0065] Optionally, the stability condition can be that the change between the current torque boundary position in the inner loop array (i.e., the torque boundary position acquired in the current control cycle) and its adjacent torque boundary positions is less than a first stability threshold. The change between the current torque boundary position and its adjacent torque boundary positions can be represented by the difference.

[0066] For example, the inner loop array contains three torque boundary positions, namely A, B, and C. A, B, and C represent the reasonable first torque boundary positions acquired in the first, second, and fourth control cycles after the target torque value is applied, respectively. Since the current control cycle is the fourth control cycle, C is the current torque boundary position. At this point, the gap determination system can calculate the difference between C and B. If this difference is less than the first stability threshold, then B is determined to be stable.

[0067] Alternatively, the stability condition can also be that the change between the current torque boundary position in the inner loop array and any torque boundary position in the inner loop array is less than a second stability threshold.

[0068] Optionally, the stability condition can also be that the angular velocity corresponding to the current torque boundary position in the inner loop array is within a set range. This set range can be a range including zero, so that the angular velocity corresponding to the current torque boundary position is close to zero.

[0069] Optionally, the stability condition can also be that the rate of change of angular velocity corresponding to the current torque boundary position in the inner loop array is less than the third stability threshold.

[0070] Optionally, the stability condition can also be that the variance of the position of each torque boundary in the inner loop array is less than the fourth stability threshold. The aforementioned fourth, third, second, and first stability thresholds can all be calibrated and configured according to specific application scenarios to adapt to different vehicle models and transmission system characteristics.

[0071] Furthermore, after determining that the torque boundary positions in the inner loop array are stable, the gap determination system can also mark these stable torque boundary positions, for example, marking them as the second torque boundary positions. Then, the second torque boundary position is the torque boundary position in the inner loop array that satisfies the stability condition.

[0072] Subsequently, if the torque boundary positions in the inner loop array are determined to be stable, the gap determination system directly increments the inner loop counter by 1; if the torque boundary positions in the inner loop array are determined to be unstable, the coordinates of the inner loop array are cleared to zero, and then the inner loop counter is incremented by 1. These coordinates of the inner loop array represent the number of stable torque boundary positions in the inner loop array, which is also the number of second torque boundary positions in the inner loop array.

[0073] In this application example, the torque boundary positions in the inner loop array of the gap determination system are unstable. When the coordinates of the inner loop array are cleared to zero, the torque boundary positions in the inner loop array can also be cleared to zero, ensuring that the torque boundary positions in the inner loop array are all reasonable and stable torque boundary positions. In this case, the torque boundary positions in the inner loop array are all the second torque boundary positions.

[0074] After incrementing the inner loop counter by 1, the gap determination system checks whether the coordinates of the inner loop array have reached a first preset number. This first preset number can be calibrated and configured according to specific application scenarios.

[0075] Optionally, when the gap determination system determines whether the inner loop array coordinates have reached a first preset number, if it determines that the inner loop array coordinates have not reached the first preset number, it continues to determine whether the inner loop counter has reached the inner loop upper limit threshold. This inner loop upper limit threshold can represent the maximum number of times the gap determination system can acquire the first torque boundary position when applying a torque target value (such as the current applied torque target value) according to the control cycle, which is also the maximum number of control cycles (i.e., the maximum sampling period). This inner loop upper limit threshold can be calibrated and configured according to specific application scenarios.

[0076] If it is determined that the inner loop counter has not reached the inner loop upper limit threshold, the gap determination system can determine that the transmission chain gear has not yet reached the gap boundary when the target torque value is applied this time, and continue to wait for the next execution cycle to collect the first torque boundary position of the next control cycle, until the inner loop array coordinates reach the first set number, or until the inner loop counter reaches the inner loop upper limit threshold.

[0077] If the inner loop counter reaches the inner loop upper limit threshold, the gap determination system can determine that the transmission chain gear has reached the gap boundary when the target torque value is applied, and can end the application of the target torque value. However, since the inner loop counter reaches the inner loop upper limit threshold only when the coordinates of the inner loop array have not reached the first set number, the gap determination system can determine that the stability check has failed when the target torque value is applied.

[0078] Optionally, when the gap determination system determines that the inner ring array coordinates have reached a first preset number, if it determines that the number of stable torque boundary positions in the inner ring array (i.e., the number of second torque boundary positions in the inner ring array) has reached the first preset number, the gap determination system can determine that the tooth surface has reached a stable contact state, and thus can determine that the stability check has passed when the target torque value is applied. At this time, regardless of whether the inner ring counter has reached the upper limit threshold of the inner ring, the gap determination system can end the acquisition of the first torque boundary position when the target torque value is applied.

[0079] After determining that the coordinates of the inner loop array have reached a first predetermined number, the gap determination system can determine the stable torque boundary position of the applied torque target value based on the stable torque boundary positions (i.e., the second torque boundary positions) in the inner loop array. For example, the gap determination system calculates the average value of the second torque boundary positions in the inner loop array (i.e., the average torque boundary position) and uses this average value as the stable torque boundary position. Another example is that the gap determination system calculates the median of the torque boundary positions in the inner loop array and uses this median as the stable torque boundary position. In this embodiment, the method by which the gap determination system determines the stable torque boundary position based on the second torque boundary positions in the inner loop array can be flexibly adjusted according to the actual application scenario.

[0080] After determining the stable torque boundary position for the applied target torque value, the gap determination system can also include this stable torque boundary position (i.e., the stable torque boundary position corresponding to the inner loop array) in the outer loop array and increment the outer loop array coordinates by 1. These outer loop array coordinates represent the number of stable torque boundary positions, indicating the number of times the stability check passes when the same target torque value is applied multiple times.

[0081] Specifically, the gap determination system includes the stable torque boundary position in the outer loop array and increments the outer loop array coordinates by 1. Then, it determines the end of the current inner loop (i.e., the end of the current stability check), controls the torque to return to zero (e.g., applies zero torque), and waits for a set duration (referred to as the second set duration) to allow the drivetrain to release to the next reloadable state before applying the next torque target value. The outer loop array coordinates indicate the effective number of times the gap determination system applies the same torque target value; the second set duration can be calibrated and configured according to specific application scenarios to adapt to different vehicle models, drivetrain stiffness characteristics, and motor rotor position sensor accuracy.

[0082] Subsequently, the gap determination system checks whether the coordinates of the outer ring array have reached a second preset number. This second preset number can be a preset number of times the gap determination system applies the same torque target value. This preset number of applications is the preset number of effective applications and can be calibrated and configured according to specific application scenarios.

[0083] Optionally, when the gap determination system determines whether the outer ring array coordinates have reached the second preset number, if it determines that the outer ring array coordinates have not reached the second preset number, it continues to determine whether the outer ring counter has reached the outer ring upper limit threshold. This outer ring upper limit threshold can indicate the maximum number of times the gap determination system can repeatedly apply the same torque target value to the vehicle, i.e., a preset maximum number of application attempts, which can be calibrated and configured according to specific application scenarios; the outer ring counter can indicate the current number of times the gap determination system applies the same torque target value to the vehicle, i.e., the total number of application attempts.

[0084] If it is determined that the outer loop timer has not reached the outer loop upper limit threshold, the gap determination system continues to apply the same torque target value to the vehicle until the outer loop array coordinates reach the second set number, or until the outer loop counter reaches the outer loop upper limit threshold.

[0085] In this embodiment of the application, the gap determination system may also clear the inner loop array, the inner loop array coordinates, and the inner loop counter before continuing to apply the same torque target value to the vehicle.

[0086] If the outer loop counter reaches the outer loop upper limit threshold, the gap determination system can determine that the maximum number of times the same torque target value has been applied to the vehicle has been reached, at which point the repeatability consistency check ends. Since the outer loop counter reaches the outer loop upper limit threshold only when the outer loop array coordinates have not reached the second preset number, in this case, the gap determination system can determine that the repeatability consistency check has failed and mark the outer loop as failed.

[0087] In one possible implementation, when determining whether the outer loop counter has reached the outer loop upper limit threshold, the gap determination system can also use whether the remaining application attempts are sufficient to make the effective application count reach the preset application count. The remaining application attempts are the difference between the preset maximum application attempts and the total number of application attempts. For example, if the preset maximum application attempts are 5, the preset application count is 3, the current total application attempts are 3, and the effective application count is 0, then the remaining application attempts are 2. Even if the stability check and repeatability check succeed in the remaining two applications of the same torque target value, the maximum effective application count is still 2, which does not reach the preset application count. Therefore, in this case, the remaining application attempts are insufficient to make the effective application count reach the preset application count. In this situation, the gap determination system can prematurely terminate the repeatability check and determine that the repeatability check has failed, thereby improving the efficiency of the repeatability check.

[0088] Optionally, when the gap determination system determines whether the coordinates of the outer ring array have reached the second set number, if it determines that the coordinates of the outer ring array have reached the second set number, it performs a consistency comparison of each stable torque boundary position in the outer ring array, that is, it determines whether each stable torque boundary position in the outer ring array meets the consistency condition.

[0089] In this embodiment, the consistency condition may include the deviation of each stable torque boundary position in the outer loop array being less than a consistency threshold. This consistency threshold can be calibrated and configured according to specific application scenarios to adapt to different vehicle models and transmission system characteristics.

[0090] This deviation can be represented by the difference between two stable torque boundary positions, and the consistency condition includes that the difference between any two torque boundary positions in the outer loop array is less than the first consistency threshold.

[0091] This deviation can also be represented by the dispersion of each stable torque boundary position in the outer loop array. This dispersion can be represented by the range, standard deviation, median filtering, the average after outlier removal, or the maximum absolute difference between any two stable torque boundary positions in the outer loop array. Furthermore, the consistency condition can include the dispersion of each stable torque boundary position in the outer loop array being less than a second consistency threshold. The second consistency threshold corresponding to the range, standard deviation, median filtering, the average after outlier removal, and the maximum absolute difference between any two stable torque boundary positions in the outer loop array can be different for each of these parameters.

[0092] When the consistency conditions are met at each stable torque boundary position in the outer loop array, the gap determination system can determine that the repeatability consistency check has passed and mark the outer loop as successful. At this point, regardless of whether the outer loop counter has reached the outer loop upper limit threshold, the gap determination system can terminate the multiple applications of the torque target value.

[0093] After confirming that the repeatability consistency check has passed, the gap determination system can determine the final torque boundary position when the same torque target value is applied multiple times, based on the stable torque boundary positions in the outer loop array. For example, the gap determination system calculates the average value of the stable torque boundary positions in the outer loop array (i.e., the average stable torque boundary position) and uses this average value as the final torque boundary position when the same torque target value is applied multiple times. Another example is that the gap determination system calculates the median of the stable torque boundary positions in the outer loop array and uses this median as the final torque boundary position when the same torque target value is applied multiple times. In this embodiment, the method by which the gap determination system determines the final torque boundary position when the same torque target value is applied multiple times, based on the stable torque boundary positions in the outer loop array, can be flexibly adjusted according to the actual application scenario.

[0094] In addition, in this embodiment of the application, regardless of whether the stability verification passes or fails, after determining that the current inner loop has ended (i.e., the current stability verification has ended), the torque is controlled to return to zero (e.g., zero torque is applied), and the system waits for a second set time to allow the transmission chain to be released to the next reloadable state before applying the next torque target value. This allows for multiple independent applications of the torque target value at the same torque boundary, thereby facilitating repeated consistency verification.

[0095] Thus, through the above method, N positive torque boundary positions and N negative torque boundary positions can be determined.

[0096] In this embodiment, the order in which the N positive torque boundary positions and the N negative torque boundary positions are determined can be flexibly adjusted according to the application scenario. Furthermore, the torque target values ​​corresponding to the N positive torque boundary positions are all positive torque target values, but their magnitudes are different; the torque target values ​​corresponding to the N negative torque boundary positions are all negative torque target values, but their magnitudes are different. However, the corresponding positive and negative torque target values ​​are two torque target values ​​with opposite directions but the same magnitude.

[0097] The following section uses an N=2 ratio as an example to explain in detail the order in which the N positive torque boundary positions and the N negative torque boundary positions are determined.

[0098] Assuming N is 2, the N positive torque boundary positions and N negative torque boundary positions are: the first positive torque boundary position, the second positive torque boundary position, the third negative torque boundary position, and the fourth negative torque boundary position. The target torque value corresponding to the first positive torque boundary position is the first positive torque target value; the target torque value corresponding to the second positive torque boundary position is the second positive torque target value; the target torque value corresponding to the first negative torque boundary position is the first negative torque target value; and the target torque value corresponding to the second negative torque boundary position is the second negative torque target value. The first positive torque target value is less than the second positive torque target value; the first negative torque target value is the same as the first positive torque target value; and the second negative torque target value is the same as the second positive torque target value. The first positive torque target value and the first negative torque target value are used to ensure tooth surface contact and minimize vehicle displacement. The second positive torque target value and the second negative torque target value are used to provide elastic reference points for determining the subsequent positive zero torque boundary position and the negative zero torque boundary position, as well as for eliminating elastic deformation.

[0099] When determining the positions of the first positive torque boundary, the second positive torque boundary, the third negative torque boundary, and the fourth negative torque boundary, the clearance determination system first applies a first positive torque target value to the vehicle, and then uses... Figure 2 The stability and consistency checks are performed in the manner shown. After both the stability and consistency checks pass, the final torque boundary position of the first positive torque target value is obtained, that is, the first positive torque boundary position is obtained.

[0100] Subsequently, the gap determination system first controls the torque to return to zero, waits for a second set time, then applies a second positive torque target value to the vehicle, and then uses... Figure 2 The stability and consistency checks are performed in the manner shown. After both the stability and consistency checks pass, the final torque boundary position of the second positive torque target value is obtained, that is, the second positive torque boundary position is obtained.

[0101] Next, the gap determination system controls the torque to return to zero and waits for a second set time to release the transmission chain to the next reloadable state, preparing for reverse loading.

[0102] After waiting for the second set time period, the gap determination system applies a first reverse torque target value to the vehicle, and then uses... Figure 2 Stability and consistency checks are performed as shown. After both checks pass, the final torque boundary position of the first reverse torque target value is obtained, i.e., the second reverse torque boundary position is obtained. Subsequently, the control torque is returned to zero, and after waiting for a second set time, the second reverse torque target value is applied to the vehicle again. Then, the following steps are taken: Figure 2 The stability and consistency checks are performed in the manner shown. After both the stability and consistency checks pass, the final torque boundary position of the second reverse torque target value is obtained, that is, the second reverse torque boundary position is obtained.

[0103] Taking the motor rotor position as an example, the temporal relationship between the target torque value and the change in motor rotor position during the determination of the first positive torque boundary position, the second positive torque boundary position, the third negative torque boundary position, and the fourth negative torque boundary position can be described as follows: Figure 3 As shown.

[0104] exist Figure 3 In the torque command, ① small positive torque represents the process of determining the first positive torque boundary position (i.e., the learning process), ② large positive torque represents the process of determining the second positive torque boundary position, ④ small reverse torque represents the process of determining the third reverse torque boundary position, and ⑤ large reverse torque represents the process of determining the fourth reverse torque boundary position; T in the torque command represents the target torque value, T1 represents the first positive torque target value, T2 represents the second positive torque target value, -T1 represents the first reverse torque target value, -T2 represents the second reverse torque target value; t_wait represents the first set duration, i.e., the torque establishment waiting time, in milliseconds (ms); n_target period represents the number of consecutive stable target periods, in the number of periods; θ U1 Indicates the position of the first positive torque boundary; θ U2 Indicates the position of the second positive torque boundary; θ D1 Indicates the position of the first reverse torque boundary; θ D2This indicates the location of the second reverse torque boundary; ① The detailed diagram of repeated loading inside the boundary shows the process of applying the first positive torque target value multiple times during the determination of the first positive torque boundary location; t_zero indicates the second set duration, i.e., the torque return-to-zero waiting time, in ms; n_max_sample indicates the maximum number of sampling periods for a single application of the torque target value, i.e., the inner loop upper limit threshold, in the number of periods; θ avg,1 The first stable torque boundary position is indicated during the determination of the first positive torque boundary position; θ avg,2 The second stable torque boundary position is indicated during the determination of the first positive torque boundary position; θ avg,3 This indicates the location of the third stable torque boundary during the determination of the first positive torque boundary location.

[0105] During the determination of the first positive torque boundary position, when attempt 4 is successful, the outer ring array coordinates reach the second set number. At this point, the gap determination system can determine the gap based on θ. avg,1 θ avg,2 θ avg,3 Perform a consistency comparison, for example, when θ avg,1 θ avg,2 θ avg,3 If the maximum absolute difference between any two stable torque boundary positions is greater than the second consistency threshold, then θ is determined. avg,1 θ avg,2 θ avg,3 The consistency condition is satisfied, and thus the position of the first positive torque boundary can be determined as a constant θ. avg,1 θ avg,2 θ avg,3 The average value.

[0106] S102, based on N positive torque boundary positions, determine the positive zero torque boundary position, and based on N negative torque boundary positions, determine the negative zero torque boundary position.

[0107] After determining N positive torque boundary positions and N negative torque boundary positions, the clearance determination system can first perform a rationality check on each of these N positive and N negative torque boundary positions. For example, it can check whether each of the N positive and N negative torque boundary positions is within a set position range. The set position ranges corresponding to different torque boundary positions can be different. This set position range can be calibrated and configured according to specific application scenarios to adapt to different vehicle models, drivetrain stiffness characteristics, and the accuracy of the motor rotor position sensor.

[0108] If it is determined that any of the N positive torque boundary positions and N negative torque boundary positions is not within the set position range, then it is determined that there is a torque boundary position among the N positive torque boundary positions and N negative torque boundary positions that has failed the rationality verification. At this time, the gap determination system can end the determination of the current gap.

[0109] If it is determined that both the N positive torque boundary positions and the N negative torque boundary positions are within the set position range, then the rationality verification of the N positive torque boundary positions and the N negative torque boundary positions is passed. At this point, the gap determination system then determines the corresponding positive zero torque boundary position and negative zero torque boundary position based on the N positive torque boundary positions and the N negative torque boundary positions. This ensures that the positive zero torque boundary position and the negative zero torque boundary position are obtained under the premise of reasonable positive torque boundary positions and negative torque boundary positions, which helps to improve the accuracy of the positive zero torque boundary position and the negative zero torque boundary position.

[0110] Specifically, the clearance determination system first determines the positive torsional stiffness based on N positive torque boundary positions, and then extrapolates the line segments corresponding to the N positive torque boundary positions based on the positive torsional stiffness to obtain the positive zero torque boundary position corresponding to zero torque; and, based on N negative torque boundary positions, determines the negative torsional stiffness, and then extrapolates the line segments corresponding to the N negative torque boundary positions based on the negative torsional stiffness to obtain the negative zero torque boundary position corresponding to zero torque.

[0111] Wherein, the positive zero torque boundary position and the negative zero torque boundary position are the torque boundary positions when the torque is zero in the lines corresponding to the first positive torque boundary position and the second positive torque boundary position, respectively; and the negative zero torque boundary position is the torque boundary position when the torque is zero in the lines corresponding to the first negative torque boundary position and the second negative torque boundary position, respectively. The positive torsional stiffness and the negative torsional stiffness are the shape parameters of the line segments corresponding to the N positive torque boundary positions and the N negative torque boundary positions, respectively. For example, when the line segments corresponding to the N positive torque boundary positions and the N negative torque boundary positions are all straight lines, the positive torsional stiffness is the reciprocal of the slope of the line segments corresponding to the N positive torque boundary positions (i.e., 1 / slope), and the negative torsional stiffness is the reciprocal of the slope of the line segments corresponding to the N negative torque boundary positions (i.e., 1 / slope).

[0112] Taking N as 2, and N positive torque boundary positions and N negative torque boundary positions as the first positive torque boundary position, the second positive torque boundary position, the first negative torque boundary position, and the second negative torque boundary position respectively, the clearance determination system can use the slope of a straight line to determine the torsional stiffness when determining the positive torsional stiffness based on the N positive torque boundary positions and the negative torsional stiffness based on the N negative torque boundary positions.

[0113] Reference Figure 4 As shown, the torque boundary position is represented by the motor rotor position, i.e., the motor rotor angle, θ. U1 θ U2 θ D1 θ D2 The meanings of T1, T2, -T1, and -T2 are the same as those of T1, T2, -T1, and -T2. Figure 3 θ shown U1 θ U2 θ D1 θ D2 The meanings of T1, T2, -T1, and -T2 are the same and will not be repeated here. The positive torsional stiffness and negative torsional stiffness can be determined using the following formula:

[0114] Among them, K pos K represents the positive torsional stiffness. neg This indicates the reverse torsional stiffness.

[0115] Continue to refer to Figure 4 As shown, under the premise that the transmission system approximately satisfies the linear torsional stiffness assumption after the tooth surfaces are engaged, after determining the positive torsional stiffness and the negative torsional stiffness, the clearance determination system extrapolates the line segments corresponding to the N positive torque boundary positions based on the positive torsional stiffness to obtain the positive zero torque boundary position corresponding to zero torque, and extrapolates the line segments corresponding to the N negative torque boundary positions based on the negative torsional stiffness to obtain the negative zero torque boundary position corresponding to zero torque. These positive and negative zero torque boundary positions can be determined using the following formulas:

[0116] Where, θ U0 θ represents the positive zero torque boundary position. D0 This indicates the position of the reverse zero torque boundary.

[0117] When N is greater than 2, the clearance determination system, when determining the positive zero torque boundary position and the negative zero torque boundary position based on N positive torque boundary positions and N negative torque boundary positions, can use methods such as multi-point linear fitting, piecewise linear fitting, or quadratic curve fitting to process the N positive torque boundary positions and N negative torque boundary positions respectively, obtaining the corresponding positive zero torque boundary position and negative zero torque boundary position. This facilitates the removal of elastic displacement caused by torque from the application position of the torque target value, thereby obtaining a clearance value that is closer to pure mechanical clearance. The processing of the N positive torque boundary positions and N negative torque boundary positions can be performed using the same fitting method.

[0118] S103, based on the positive zero torque boundary position and the negative zero torque boundary position, determines the side clearance of the transmission chain teeth in the vehicle.

[0119] After obtaining the positive and negative zero torque boundary positions, the clearance determination system can determine the clearance using these positions. For example, the clearance determination system can use the difference between the positive and negative zero torque boundary positions as the clearance, as shown in the following formula:

[0120] Where, Δθ gap Indicates a gap.

[0121] By using the above method, the difference between the positive zero torque boundary position and the negative zero torque boundary position is used as the gap, thereby basically eliminating the elastic displacement caused by the applied torque, so that the determined gap is approximately the pure mechanical gap of the tooth side at the current operating temperature (such as the current motor oil temperature).

[0122] To ensure that the determined clearance is more reasonable and accurate, the clearance determination system determines the clearance (i.e., the preliminary clearance) based on the positive zero torque boundary position and the reverse zero torque boundary position. Then, it performs a reasonableness check on the preliminary clearance. Once the reasonableness check is passed, the preliminary clearance is used as the clearance determined in this case.

[0123] In this embodiment of the application, when the gap determination system performs a reasonableness check on the preliminary gap, it can use a first reasonableness check method. Specifically, the gap determination system first retrieves the previously determined gap (i.e., the previous gap) from the storage space. This storage space can be non-volatile memory (NvM), flash memory (Flash), electrically erasable programmable read-only memory (EEPROM), or other non-volatile storage media.

[0124] Subsequently, the gap determination system calculates the change between the initial gap and the previous gap, and determines whether the change is less than a set change threshold; if so, the rationality check of the initial gap is deemed to have passed; otherwise, the rationality check of the initial gap is deemed to have failed, and the gap determination process ends.

[0125] The change between the initial gap and the previous gap can be determined by the difference or the absolute difference, but it is not limited to this.

[0126] Optionally, the clearance determination system can also use a second rationality verification method when performing a rationality verification on the initial clearance. This second rationality verification method involves checking whether the positive torsional stiffness and the negative torsional stiffness meet the cross-verification requirements. For example, whether the difference between the positive torsional stiffness and the negative torsional stiffness is within a set difference range. If it is, then the positive torsional stiffness and the negative torsional stiffness meet the cross-verification requirements; otherwise, they do not. This set difference range can be calibrated and configured according to specific application scenarios. If either the second or first rationality verification method fails, the initial clearance rationality verification is deemed to have failed, and the clearance determination ends. If both the second and first rationality verification methods pass, the initial clearance rationality verification is deemed to have passed.

[0127] Furthermore, after the rationality verification of the preliminary gap is passed, the gap determination system can write the preliminary gap into the storage space as the determined gap.

[0128] Furthermore, when writing the determined gap to storage, the gap determination system can also write the corresponding learning information (such as timestamps, operating temperatures (e.g., motor oil temperature)) to storage, thereby completing the power-down self-learning of the gap. For example, when writing the gap to storage, the gap determination system can write the gap and time difference to the corresponding positions according to the range corresponding to the motor oil temperature. If the learning fails or the reasonableness verification of the gap fails, it can retain historical valid gaps, use a default gap, limit the single update range, or record a Diagnostic Trouble Code (DTC) / diagnostic event and delay retry until the next time the access conditions are met.

[0129] Taking NvM storage space as an example, the steps of the gap determination system after obtaining the gap can be referred to Figure 5 As shown, after obtaining the actual gap (i.e., the preliminary gap that has passed the rationality check) through this power-down self-learning, the current gap in NvM is saved as the historical gap in NvM; the actual gap obtained through this self-learning (i.e., the preliminary gap that has passed the rationality check), along with the motor oil temperature and timestamp during the learning process, are saved as the current gap in NvM; then a state update is performed, and the power-down self-learning ends. In this application example, the state of the gap determination system can be a gap self-learning success state, a gap self-learning failure state, or a gap self-learning unexpected interruption state. Therefore, after saving the actual gap obtained through this self-learning, along with the motor oil temperature and timestamp during the learning process, as the current gap in NvM, the state update can be: updating the current state to a gap self-learning success state.

[0130] When the vehicle is powered on again, the gaps stored in the storage space can be used.

[0131] For example, taking NvM storage space as an example, refer to Figure 6 As shown, when the vehicle is powered on again, the current clearance in the NvM is read; the rationality of this current clearance is then checked. This rationality check can be performed using the first rationality check method described above. Once the rationality check passes, the current clearance is used as the clearance reference value for torque zero-crossing control within this power-on cycle, thereby completing the clearance power-on initialization and realizing clearance reference value management across power-on cycles. This helps to reduce the reliance on one-time calibration on the test bench or fixed constants.

[0132] If the rationality check fails, it is determined whether a historical valid gap exists in the NvM (i.e., a historical gap that passed the rationality check). If a historical valid gap exists in the NvM, it is used, for example, as the gap reference value for torque zero-crossing control in the current power-on cycle. If no historical valid gap exists in the NvM, the default gap is used, for example, as the gap reference value for torque zero-crossing control in the current power-on cycle. This completes the gap power-on initialization.

[0133] Optionally, the clearance determination system can also display on the vehicle's infotainment system or diagnostic tool the clearance determined this time, its corresponding motor oil temperature and timestamp, historical clearances, their corresponding motor oil temperature and timestamps, clearance determination status (e.g., success or failure), the reason for failure, and whether the clearance reference value for torque zero-crossing control during this power-on cycle is the clearance determined in the clearance determination process of this application embodiment, a historical valid clearance, or a default clearance. Furthermore, the clearance determination system can also plot a clearance change trend curve based on multiple clearance determination records, facilitating users or after-sales personnel to make auxiliary judgments by combining vehicle usage status, maintenance records, and clearance change trends.

[0134] In this embodiment of the application, when the rationality check of the current gap in NvM fails, the gap-related status can also be recorded for diagnosis.

[0135] Furthermore, during the clearance determination process (i.e., the clearance self-learning process), if any of the following occurs: determination timeout (i.e., learning timeout), failure to pass both stability and consistency checks at any torque boundary position, any torque boundary position exceeding the set position range, driver request for drive, gear change, vehicle preparation for start-up, vehicle malfunction (such as high voltage or communication malfunction), or failure to pass the reasonableness check of the determined clearance, the clearance determination system can terminate the clearance determination. In this case, the clearance determination system can control the torque to return to zero to prioritize driving requests and system safety. Moreover, the clearance determination system does not update the current clearance. If a historical valid clearance exists in the storage space, it is retained; if no historical valid clearance exists in the storage space, the default clearance is used upon the next power-on.

[0136] For example, refer to Figure 7 As shown, if any of the following occurs in the gap determination system: the entry conditions are not met, the torque boundary position fails the rationality check, or the determined gap fails the rationality check, the system will abandon the learning result and exit the self-learning process. Only after the entry conditions are met, all torque boundary positions are successfully determined, all determined torque boundary positions pass the rationality check, and the determined gap passes the rationality check, will the determined gap be written into the storage space and the power-down self-learning process of the gap (i.e., the gap determination process) be terminated.

[0137] Furthermore, in this embodiment, the aforementioned gap determination system may include a VCU, an MCU / PEU, a drive motor, a reducer and transmission chain, a motor rotor position acquisition unit, wheels, and an NvM. The composition of the gap determination system and the control relationships between its units are as follows: Figure 8 As shown in the diagram. The VCU is used for gap self-learning (i.e., gap determination) including admission judgment, process scheduling, gap calculation and result verification after boundary learning, and storage management of learning results in the NvM. During gap self-learning, the VCU sends torque commands for each stage to the MCU / PEU and receives status feedback from the MCU / PEU to perform repeatability consistency checks. The MCU / PEU executes the target torque output according to the torque commands issued by the VCU, acquires the motor rotor position after torque is established, and performs stability checks. The motor rotor position acquisition unit acquires the angular position of the motor rotor at each stage as the basis for torque boundary position determination and gap calculation. The NvM stores the gaps that have passed the rationality check and their associated information for retrieval upon the next power-on.

[0138] Specifically, the VCU first performs an admission judgment for gap self-learning, that is, it determines whether the current environment of the vehicle meets the admission conditions. When the VCU determines that it can enter the gap self-learning, it issues torque commands for each stage (i.e., the application stage of each torque target value) to the MCU / PEU (this torque command carries the torque target value of the corresponding stage). For example, in the stage of determining the first positive torque boundary position, the VCU issues a first torque command to the MCU / PEU, which carries the first positive torque target value corresponding to the first positive torque boundary position.

[0139] After receiving the torque command, the MCU / PEU drives the drive motor to generate a corresponding drive current to apply the target torque value. This target torque value is transmitted to the wheels, which are mechanically connected to the reducer and transmission chain, thereby driving the vehicle. During this process, the motor rotor rotates, and the motor rotor acquisition unit can acquire the motor rotor position (i.e., the angular position of the motor rotor during the application of the target torque value) and send this position to the MCU / PEU. Simultaneously, the drive motor provides status feedback to the MCU / PEU, such as the motor status after generating the corresponding drive current.

[0140] After receiving the motor rotor position from the motor rotor acquisition unit, the MCU / PEU performs a stability check based on that position and then provides status feedback to the VCU based on the result. For example, if the MCU / PEU determines that the stability check for the applied torque target value has passed, it will provide feedback to the VCU on the stable torque boundary position obtained after applying the target torque value; or, if the MCU / PEU determines that the stability check for the applied torque target value has failed, it will provide feedback to the VCU indicating that the stability check for the applied torque target value has failed.

[0141] Subsequently, the VCU performs a repeatability check based on the stable torque boundary position or the information indicating that the stability check failed after multiple applications of the target torque value fed back by the MCU / PEU. Then, based on the stability check and the repeatability check, the VCU determines the gap by obtaining the various reverse torque boundary positions and the forward torque boundary positions. The VCU then performs a rationality check on the obtained gap and stores the gap in the NvM after the rationality check passes.

[0142] Optionally, in the clearance determination system, the MCU / PEU can independently determine the torque boundary position and calculate the clearance after meeting the access conditions, and upload the determined clearance and related information to the VCU; alternatively, the power domain controller or integrated vehicle domain controller can uniformly complete the process scheduling, torque boundary position acquisition and determination, and clearance storage.

[0143] Based on the same inventive concept, this application also provides a gap determination system, such as... Figure 9 The diagram shown is a structural schematic of a gap determination system provided in this application. The system includes: The first determining module 901 is used to determine N positive torque boundary positions and N negative torque boundary positions corresponding to the vehicle; where N is a positive integer greater than 1. The second determining module 902 is used to determine the positive zero torque boundary position based on N positive torque boundary positions, and to determine the reverse zero torque boundary position based on N reverse torque boundary positions. Processing module 903 is used to determine the backlash of the transmission chain teeth in the vehicle based on the positive zero torque boundary position and the negative zero torque boundary position.

[0144] In one possible implementation, each of the N positive torque boundary positions and N negative torque boundary positions is determined as follows: the same torque target value is applied to the vehicle multiple times, and after each application of the torque target value, the first torque boundary position is collected multiple times according to the control cycle; wherein, after the current application of the torque target value, the torque is controlled to return to zero and a set time is waited before the next application of the torque target value; based on the multiple first torque boundary positions, stability verification and repeatability consistency verification are performed; if it is determined that both stability verification and repeatability consistency verification are passed, the final torque boundary position is obtained based on the multiple first torque boundary positions.

[0145] In one possible implementation, the stability verification includes: after applying the target torque value, obtaining a target array; wherein the torque boundary positions contained in the target array are all first torque boundary positions within a set range; determining whether the number of second torque boundary positions in the target array reaches a first set number; wherein the second torque boundary positions are torque boundary positions in the target array that satisfy the stability condition; if yes, then the stability verification of the applied torque target value is determined to be passed, and based on each second torque boundary position in the target array, the stable torque boundary position of the applied torque target value is determined; if no, then the stability verification of the applied torque target value is determined to be failed.

[0146] In one possible implementation, the stability condition is that the change between the current torque boundary position and its adjacent torque boundary positions in the target array is less than a first stability threshold, or the change between the current torque boundary position and any torque boundary position in the target array is less than a second stability threshold, or the angular velocity corresponding to the current torque boundary position is within a set range, or the rate of change of the angular velocity is less than a third stability threshold, or the position variance of each torque boundary position in the target array is less than a fourth stability threshold.

[0147] In one possible implementation, when the first determining module 901 determines the stable torque boundary position of the target torque value applied this time based on each of the second torque boundary positions in the target array, it is specifically used to determine the average torque boundary position between each of the second torque boundary positions in the target array; and to use the average torque boundary position as the stable torque boundary position of the target torque value applied this time.

[0148] In one possible implementation, the repeatability check includes: determining whether the number of stable torque boundary positions obtained after applying the same torque target value to the vehicle multiple times reaches a second preset number; if yes, when it is determined that each stable torque boundary position meets the consistency condition, the repeatability check is determined to be passed, and the final torque boundary position is determined based on the multiple stable torque boundary positions; wherein, the consistency condition includes that the deviation of each stable torque boundary position is less than a consistency threshold; if no, the repeatability check is determined to be failed.

[0149] In one possible implementation, if the deviation is the difference between two stable torque boundary positions, then the consistency condition includes that the difference between any two stable torque boundary positions is less than a first consistency threshold; or, if the deviation is the dispersion of each stable torque boundary position, then the consistency condition includes that the dispersion is less than a second consistency threshold.

[0150] In one possible implementation, when determining the final torque boundary position based on multiple stable torque boundary positions, the first determining module 901 is specifically used to determine the average stable torque boundary position among the multiple stable torque boundary positions; and to use the average stable torque boundary position as the final torque boundary position.

[0151] In one possible implementation, when the second determining module 902 determines the positive zero torque boundary position based on N positive torque boundary positions and the reverse zero torque boundary position based on N negative torque boundary positions, it is specifically used to determine whether both the N positive torque boundary positions and the N negative torque boundary positions are within a set position range; if so, it determines the positive zero torque boundary position based on the N positive torque boundary positions and the reverse zero torque boundary position based on the N negative torque boundary positions.

[0152] In one possible implementation, when the second determining module 902 determines the positive zero torque boundary position based on N positive torque boundary positions and the reverse zero torque boundary position based on N negative torque boundary positions, it is specifically used to determine the positive torsional stiffness based on the N positive torque boundary positions, and extrapolate the line segments corresponding to the N positive torque boundary positions based on the positive torsional stiffness to obtain the positive zero torque boundary position corresponding to zero torque; wherein, the positive torsional stiffness is the shape parameter of the line segments corresponding to the N positive torque boundary positions; and to determine the reverse torsional stiffness based on the N negative torque boundary positions, and extrapolate the line segments corresponding to the N negative torque boundary positions based on the reverse torsional stiffness to obtain the reverse zero torque boundary position corresponding to zero torque; wherein, the reverse torsional stiffness is the shape parameter of the line segments corresponding to the N negative torque boundary positions.

[0153] In one possible implementation, when the processing module 903 determines the clearance on the transmission chain tooth side of the vehicle based on the positive zero torque boundary position and the negative zero torque boundary position, it specifically uses the difference between the positive zero torque boundary position and the negative zero torque boundary position as the initial clearance on the transmission chain tooth side of the vehicle; performs a rationality check on the initial clearance; and in response to the rationality check passing, uses the initial clearance as the clearance; wherein, the rationality check includes: if it is determined that the change between the initial clearance and the previous clearance in the storage space is less than a set change threshold, then the rationality check is determined to pass.

[0154] In one possible implementation, after determining the backlash of the transmission chain teeth in the vehicle, the processing module 903 is further configured to write the backlash and the corresponding learning information into a storage space; when the vehicle is powered on again, the current backlash in the storage space is checked for reasonableness; if the current backlash passes the reasonableness check, the current backlash is used as the backlash reference value for torque zero-crossing control; if the current backlash fails the reasonableness check, the historical valid backlash or default backlash in the storage space is used as the backlash reference value for torque zero-crossing control.

[0155] Based on the same inventive concept, this application also provides an electronic device that can realize the function of the aforementioned gap determination system. (Refer to...) Figure 10 The aforementioned electronic devices include: At least one processor 1001 and a memory 1002 connected to at least one processor 1001. In this embodiment, the specific connection medium between the processor 1001 and the memory 1002 is not limited. Figure 10 The example shown is the connection between processor 1001 and memory 1002 via bus 1000. Bus 1000 is... Figure 10 The connections between other components are shown in bold lines only and are not intended to be limiting. The Bus 1000 can be divided into address bus, data bus, control bus, etc., for ease of representation. Figure 10 The term 1001 is represented by a single thick line, but this does not imply that there is only one bus or one type of bus. Alternatively, the processor 1001 can also be called a controller; there are no restrictions on the name.

[0156] In this embodiment, memory 1002 stores instructions executable by at least one processor 1001. By executing the instructions stored in memory 1002, at least one processor 1001 can perform the gap determination method described above. Processor 1001 can implement... Figure 9 The system shown illustrates the functions of each module.

[0157] The processor 1001 is the control center of the system. It can connect to various parts of the control device through various interfaces and lines. By running or executing instructions stored in memory 1002 and calling data stored in memory 1002, it can monitor the various functions and data processing of the system as a whole.

[0158] In one possible design, processor 1001 may include one or more processing units. Processor 1001 may integrate an application processor and a modem processor, wherein the application processor mainly handles the operating system, user interface, and applications, and the modem processor mainly handles wireless communication. It is understood that the modem processor may also not be integrated into processor 1001. In some embodiments, processor 1001 and memory 1002 may be implemented on the same chip; in some embodiments, they may also be implemented on separate chips.

[0159] The processor 1001 can be a general-purpose processor, such as a central processing unit (CPU), digital signal processor, application-specific integrated circuit, field-programmable gate array or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, capable of implementing or executing the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the gap determination method disclosed in the embodiments of this application can be directly manifested as being executed by a hardware processor, or executed by a combination of hardware and software modules within the processor.

[0160] Memory 1002, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. Memory 1002 may include at least one type of storage medium, such as flash memory, hard disk, multimedia card, card-type memory, random access memory (RAM), static random access memory (SRAM), programmable read-only memory (PROM), read-only memory (ROM), EEPROM, magnetic storage, magnetic disk, optical disk, etc. Memory 1002 can be any other medium capable of carrying or storing desired program code in the form of instructions or data structures that can be accessed by a computer, but is not limited thereto. In the embodiments of this application, memory 1002 can also be a circuit or any other device capable of implementing storage functions for storing program instructions and / or data.

[0161] By designing and programming the processor 1001, the code corresponding to the gap determination method described in the foregoing embodiments can be embedded into the chip, thereby enabling the chip to execute the code during operation. Figure 1 The steps of the gap determination method in the illustrated embodiment are described. How to design and program the processor 401 is a technique well-known to those skilled in the art and will not be elaborated upon here.

[0162] Based on the same inventive concept, embodiments of this application also provide a storage medium storing computer instructions that, when executed on a computer, cause the computer to perform the gap determination method described above.

[0163] In some possible implementations, various aspects of the gap determination method provided in this application may also be implemented in the form of a program product, which includes program code that, when the program product is run on a device, causes the control device to perform the steps in the gap determination method according to the various exemplary embodiments of this application described above.

[0164] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0165] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0166] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0167] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0168] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for determining a gap, characterized in that, include: Determine N positive torque boundary positions and N negative torque boundary positions corresponding to the vehicle; where N is a positive integer greater than 1; Based on the N positive torque boundary positions, a positive zero torque boundary position is determined, and based on the N negative torque boundary positions, a negative zero torque boundary position is determined; wherein, determining the positive zero torque boundary position based on the N positive torque boundary positions and the negative zero torque boundary position based on the N negative torque boundary positions includes: determining a positive torsional stiffness based on the N positive torque boundary positions, and extrapolating the line segments corresponding to the N positive torque boundary positions based on the positive torsional stiffness to obtain the positive zero torque boundary position corresponding to zero torque; the positive torsional stiffness is the shape parameter of the line segments corresponding to the N positive torque boundary positions; and determining a negative torsional stiffness based on the N negative torque boundary positions, and extrapolating the line segments corresponding to the N negative torque boundary positions based on the negative torsional stiffness to obtain the negative zero torque boundary position corresponding to zero torque; the negative torsional stiffness is the shape parameter of the line segments corresponding to the N negative torque boundary positions. The backlash of the transmission chain teeth in the vehicle is determined based on the positive zero torque boundary position and the negative zero torque boundary position.

2. The method as described in claim 1, characterized in that, Each of the N positive torque boundary positions and the N negative torque boundary positions is determined in the following way: The same torque target value is applied to the vehicle multiple times, and after each application of the torque target value, the position of the first torque boundary is collected multiple times according to the control cycle; wherein, after the current application of the torque target value, the torque is controlled to return to zero and wait for a set time before the next application of the torque target value is performed; Based on multiple first torque boundary positions, stability verification and repeatability consistency verification are performed; If both the stability check and the repeatability consistency check pass, the final torque boundary position is obtained based on the multiple first torque boundary positions.

3. The method as described in claim 2, characterized in that, The stability check includes: After applying the target torque value, a target array is obtained; wherein, the torque boundary positions contained in the target array are all first torque boundary positions within a set range; Determine whether the number of second torque boundary positions in the target array reaches a first preset number; wherein, the second torque boundary position is the torque boundary position in the target array that satisfies the stability condition; If so, then the stability check of the applied torque target value is determined to be passed, and the stable torque boundary position of the applied torque target value is determined based on each of the second torque boundary positions in the target array. If not, then the stability check for applying the target torque value this time has failed.

4. The method as described in claim 3, characterized in that, The stability condition is that the change between the current torque boundary position and its adjacent torque boundary positions in the target array is less than a first stability threshold, or the change between the current torque boundary position and any torque boundary position in the target array is less than a second stability threshold, or the angular velocity corresponding to the current torque boundary position is within a set range, or the rate of change of the angular velocity is less than a third stability threshold, or the position variance of each torque boundary position in the target array is less than a fourth stability threshold.

5. The method as described in claim 3, characterized in that, Determining the stable torque boundary position for applying the target torque value based on each of the second torque boundary positions in the target array includes: Determine the average torque boundary position between each of the second torque boundary positions in the target array; The average torque boundary position is taken as the stable torque boundary position for applying the target torque value this time.

6. The method as described in claim 3, characterized in that, The repeatability consistency check includes: Determine whether the number of stable torque boundary positions obtained after applying the same torque target value to the vehicle multiple times reaches a second preset number; If so, when it is determined that each of the stable torque boundary positions meets the consistency condition, the repeated consistency check is determined to be passed, and the final torque boundary position is determined based on the multiple stable torque boundary positions; wherein, the consistency condition includes that the deviation of each of the stable torque boundary positions is less than the consistency threshold. If not, the repeatability consistency check has failed.

7. The method as described in claim 6, characterized in that, The deviation is the difference between the two stable torque boundary positions, then the consistency condition includes any two stable torque boundary positions having a difference less than a first consistency threshold; or The deviation is the dispersion of each of the stable torque boundary positions; then the consistency condition includes the dispersion being less than the second consistency threshold.

8. The method as described in claim 6, characterized in that, Determining the final torque boundary position based on multiple stable torque boundary positions includes: Determine the average stable torque boundary position among the plurality of said stable torque boundary positions; The average stable torque boundary position is taken as the final torque boundary position.

9. The method as described in claim 1, characterized in that, The step of determining the positive zero torque boundary position based on the N positive torque boundary positions, and determining the reverse zero torque boundary position based on the N reverse torque boundary positions, includes: Determine whether the N positive torque boundary positions and the N negative torque boundary positions are all within a set position range; If so, then based on the N positive torque boundary positions, the positive zero torque boundary position is determined, and based on the N negative torque boundary positions, the negative zero torque boundary position is determined.

10. The method as described in claim 1, characterized in that, Determining the backlash of the transmission chain teeth in the vehicle based on the positive zero torque boundary position and the negative zero torque boundary position includes: The difference between the positive zero torque boundary position and the negative zero torque boundary position is used as the initial clearance on the transmission chain tooth side in the vehicle. The initial gap is subjected to a rationality check. In response to the rationality check passing, the initial gap is taken as the gap. The rationality check includes: if it is determined that the change between the initial gap and the previous gap in the storage space is less than a set change threshold, then the rationality check is determined to pass.

11. The method as described in claim 10, characterized in that, After establishing the initial gap as the gap, the method further includes: Write the gap and the learning information corresponding to the gap into the storage space; When the vehicle is powered on again, the reasonableness check is performed on the current gap in the storage space; If the current gap passes the rationality check, then the current gap is used as the gap reference value for torque zero-crossing control; If the current gap fails the rationality check, then the historical valid gap or default gap in the storage space will be used as the gap reference value for torque zero-crossing control.

12. A gap determination system, characterized in that, include: The first determining module is used to determine N positive torque boundary positions and N negative torque boundary positions corresponding to the vehicle; wherein, N is a positive integer greater than 1; The second determining module is configured to determine a positive zero torque boundary position based on the N positive torque boundary positions, and to determine a reverse zero torque boundary position based on the N negative torque boundary positions. Specifically, when determining the positive zero torque boundary position based on the N positive torque boundary positions, the second determining module is configured to determine a positive torsional stiffness based on the N positive torque boundary positions, and extrapolate the line segments corresponding to the N positive torque boundary positions based on the positive torsional stiffness to obtain the positive zero torque boundary position corresponding to zero torque; the positive torsional stiffness is a shape parameter of the line segments corresponding to the N positive torque boundary positions. Furthermore, the second determining module is configured to determine a reverse torsional stiffness based on the N negative torque boundary positions, and extrapolate the line segments corresponding to the N negative torque boundary positions based on the reverse torsional stiffness to obtain the reverse zero torque boundary position corresponding to zero torque; the reverse torsional stiffness is a shape parameter of the line segments corresponding to the N negative torque boundary positions. The processing module is used to determine the backlash of the transmission chain teeth in the vehicle based on the positive zero torque boundary position and the negative zero torque boundary position.

13. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor, when executing a computer program stored in the memory, implements the method of any one of claims 1-11.

14. A computer program product, characterized in that, The computer program product includes: computer program code, which, when run on a computer, causes the computer to perform the method according to any one of claims 1-11.

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