Vehicle transmission system parameter measurement method, device and equipment, storage medium and electric vehicle

Abstract

The invention discloses a vehicle transmission system parameter measuring method, device and equipment, a storage medium and an electric automobile, and the method comprises the steps that when a vehicle meets a measuring condition, a vehicle motor is controlled to periodically output torque, and the measuring condition comprises that the vehicle is in a parking state; measuring to-be-measured transmission system parameters of the vehicle based on motor operation data collected in the torque output process of the vehicle motor, wherein the to-be-measured transmission system parameters comprise a mechanical clearance parameter and a half shaft rigidity parameter; when the vehicle is in the parking state, the motor of the vehicle is controlled to periodically output the torque, at the moment, the motor is controlled to output the torque so that a gear pair of the vehicle transmission system can be in a tooth attaching state, a half shaft deforms, and the parameters of the to-be-measured transmission system of the vehicle are measured based on the motor operation data collected in the torque output process. Therefore, transmission system parameter measurement after vehicle parts are loaded is realized, and the measurement efficiency and the measurement precision of mechanical clearance parameters and half shaft rigidity parameters are effectively improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a method, apparatus, device, storage medium, and electric vehicle for measuring vehicle transmission system parameters. Background Technology

[0002] The vehicle drivetrain is the system that transmits power to a vehicle, including the drive motor, reducer, differential, left and right half-shafts, and wheels. Obtaining accurate parameters of the drivetrain is crucial for building a drivetrain model and implementing algorithms such as wheel speed estimation, drivetrain impact suppression, and pre-torque calculation. Among these, measuring the half-shaft stiffness and mechanical clearance is particularly challenging. Currently, the half-shaft stiffness and mechanical clearance can only be measured before components are installed in the vehicle using specialized equipment and instruments. However, this process is complex, costly, and does not allow for accurate and efficient measurement of vehicle drivetrain parameters after components are installed. Summary of the Invention

[0003] The main objective of this invention is to provide a method, apparatus, device, storage medium, and electric vehicle for measuring vehicle transmission system parameters, aiming to solve the technical problems of existing transmission system parameter measurement being complex, costly, and unable to accurately and efficiently measure the vehicle transmission system after installation.

[0004] To achieve the above objectives, the present invention provides a method for measuring vehicle transmission system parameters, the method comprising the following steps:

[0005] When the vehicle meets the measurement conditions, the vehicle motor is controlled to periodically output torque, the measurement conditions including the vehicle being in a parked state;

[0006] The parameters of the vehicle's transmission system to be tested are measured based on the motor operation data collected during the torque output process of the vehicle motor. The parameters of the transmission system to be tested include mechanical clearance parameters and half-shaft stiffness parameters.

[0007] Optionally, the motor operating data includes the rotor angle data of the vehicle motor; the measurement of the vehicle's transmission system parameters based on the motor operating data collected during the torque output process of the vehicle motor includes:

[0008] The clearance angle and half-shaft torsion angle of the vehicle transmission system are determined based on the rotor angle data collected during the torque output process of the vehicle motor.

[0009] The mechanical clearance parameters and axle stiffness parameters of the vehicle are determined based on the clearance angle and the axle torsion angle.

[0010] Optionally, determining the clearance angle and half-shaft torsion angle of the vehicle transmission system based on the rotor angle data collected during the torque output process of the vehicle motor includes:

[0011] Waveform separation is performed on the rotor angle data collected during the torque output process of the vehicle motor to obtain gap data and stiffness data;

[0012] The clearance angle and half-shaft torsion angle of the vehicle transmission system are determined based on the clearance data and the stiffness data.

[0013] Optionally, determining the clearance angle and half-shaft torsional angle of the vehicle transmission system based on the clearance data and the stiffness data includes:

[0014] Acquire torque output data during the torque output process of the vehicle motor;

[0015] Based on the torque output data, determine the torque change information and torque zero-crossing moment information during the torque output process of the vehicle motor;

[0016] The clearance angle of the vehicle transmission system is determined based on the zero-crossing time information and the clearance data;

[0017] The torsional angle of the half-shaft of the vehicle drivetrain is determined based on the torque variation information and the stiffness data.

[0018] Optionally, determining the mechanical clearance parameters and axle stiffness parameters of the vehicle based on the clearance angle and the axle torsion angle includes:

[0019] Obtain the transmission ratio parameters of the vehicle;

[0020] The mechanical clearance parameters of the vehicle are determined based on the transmission ratio parameters and the clearance angle.

[0021] Obtain torque change information during the torque output process of the vehicle motor;

[0022] The information on the change of the motor rotor during the torque output process of the vehicle motor is obtained based on the motor rotor angle parameters.

[0023] The axle stiffness parameters of the vehicle are determined based on the torque change information, the motor rotor change information, and the axle torsion angle.

[0024] Optionally, the measurement conditions include at least one of the following:

[0025] The vehicle is in a parked state, and the parking duration of the vehicle reaches a preset duration threshold, and the total mileage of the vehicle exceeds a preset mileage threshold.

[0026] The vehicle is in a parked state, and the duration of the parking of the vehicle reaches a preset duration threshold, and the total driving time of the vehicle exceeds a preset driving time threshold.

[0027] Furthermore, to achieve the above objectives, the present invention also proposes a vehicle transmission system parameter measuring device, the vehicle transmission system parameter measuring device comprising:

[0028] The motor control module is used to control the vehicle motor to periodically output torque when the vehicle meets the measurement conditions, the measurement conditions including the vehicle being in a parked state;

[0029] The parameter measurement module is used to measure the parameters of the vehicle's transmission system to be tested based on the motor operation data collected during the torque output process of the vehicle motor. The parameters of the transmission system to be tested include mechanical clearance parameters and half-shaft stiffness parameters.

[0030] In addition, to achieve the above objectives, this application also proposes a vehicle transmission system parameter measuring device, the device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the vehicle transmission system parameter measuring method as described above.

[0031] In addition, to achieve the above objectives, this application also proposes a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the vehicle transmission system parameter measurement method described above.

[0032] In addition, to achieve the above objectives, this application also proposes an electric vehicle that includes the vehicle drivetrain parameter measuring device as described above.

[0033] In addition, to achieve the above objectives, this application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the vehicle transmission system parameter measurement method described above.

[0034] This invention measures the transmission system parameters of a vehicle by controlling the vehicle motor to periodically output torque when the vehicle is in a parked state. The measured parameters include mechanical clearance parameters and half-shaft stiffness parameters. Because this invention controls the vehicle motor to periodically output torque while the vehicle is parked, the controlled torque output causes the gear pairs in the transmission system to be in a close-gear state, and the half-shaft to deform. By measuring the transmission system parameters based on the motor operating data collected during the torque output process, this invention enables the measurement of transmission system parameters after vehicle components are installed, effectively improving the measurement efficiency and accuracy of mechanical clearance and half-shaft stiffness parameters. Attached Figure Description

[0035] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0036] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the structure of a vehicle transmission system parameter measuring device in the hardware operating environment involved in the embodiments of the present invention;

[0038] Figure 2 This is a flowchart illustrating the first embodiment of the vehicle transmission system parameter measurement method of the present invention;

[0039] Figure 3 This is a schematic diagram of the vehicle motor output torque in the vehicle parked state in the first embodiment of the vehicle transmission system parameter measurement method of the present invention;

[0040] Figure 4 This is a flowchart illustrating the second embodiment of the vehicle transmission system parameter measurement method of the present invention;

[0041] Figure 5 This is a schematic diagram of the vehicle motor torque output waveform in the second embodiment of the vehicle transmission system parameter measurement method of the present invention;

[0042] Figure 6 This is a waveform diagram illustrating the change in motor rotor angle during the output torque of the vehicle motor in the second embodiment of the vehicle transmission system parameter measurement method of the present invention.

[0043] Figure 7 This is a schematic diagram of the rotor angle waveform calculation points in the second embodiment of the vehicle transmission system parameter measurement method of the present invention;

[0044] Figure 8 This is a schematic diagram of the spacing between the extended lines of the calculation points in the second embodiment of the vehicle transmission system parameter measurement method of the present invention;

[0045] Figure 9 This is a waveform diagram of the motor rotor angle in the second embodiment of the vehicle transmission system parameter measurement method of the present invention;

[0046] Figure 10 This is a waveform diagram of motor torque output in the second embodiment of the vehicle transmission system parameter measurement method of the present invention;

[0047] Figure 11This is a structural block diagram of the first embodiment of the vehicle transmission system parameter measuring device of the present invention.

[0048] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0049] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0050] Reference Figure 1 , Figure 1 This is a schematic diagram of the vehicle transmission system parameter measurement device structure in the hardware operating environment involved in the embodiments of the present invention.

[0051] like Figure 1 As shown, the vehicle transmission system parameter measuring device may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen or an input unit such as a keyboard; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wireless-Fidelity (Wi-Fi) interface). The memory 1005 may be high-speed random access memory (RAM) or stable non-volatile memory (NVM), such as a disk storage device. The memory 1005 may also optionally be a storage device independent of the aforementioned processor 1001.

[0052] Those skilled in the art will understand that Figure 1 The structure shown does not constitute a limitation on the vehicle drivetrain parameter measuring device, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0053] like Figure 1 As shown, the memory 1005, which is a computer-readable storage medium, may include an operating system, a network communication module, a user interface module, and a vehicle transmission system parameter measurement program.

[0054] exist Figure 1In the vehicle transmission system parameter measuring device shown, the network interface 1004 is mainly used for data communication with the network server; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the vehicle transmission system parameter measuring device of the present invention can be set in the vehicle transmission system parameter measuring device. The vehicle transmission system parameter measuring device calls the vehicle transmission system parameter measuring program stored in the memory 1005 through the processor 1001 and executes the vehicle transmission system parameter measuring method provided in the embodiment of the present invention.

[0055] This invention provides a method for measuring vehicle transmission system parameters, referring to... Figure 2 , Figure 2 This is a flowchart illustrating the first embodiment of the vehicle transmission system parameter measurement method of the present invention.

[0056] In this embodiment, the method for measuring vehicle transmission system parameters includes the following steps:

[0057] Step S10: When the vehicle meets the measurement conditions, control the vehicle motor to periodically output torque.

[0058] It should be noted that currently, in order to obtain the half-shaft stiffness and mechanical clearance of a vehicle's transmission system, empirical formulas and professional equipment are usually used for measurement. However, the accuracy of empirical formulas is poor, and half-shafts contain irregularly shaped components such as universal connectors, making it difficult to calculate using empirical formulas. On the other hand, professional equipment measurement is complex to operate, costly, and cannot be applied to the measurement of transmission system parameters after installation.

[0059] It should be understood that this embodiment is applied to the transmission system of an electric vehicle, which includes a vehicle motor, a reducer, a differential, and half-shafts. This embodiment can determine whether the vehicle meets the parking requirements after installation. When the vehicle is in the parking state, the vehicle motor is controlled to periodically output torque. This torque output causes the gear pairs in the transmission system to be in a tooth-closed state, and the half-shafts to deform. Based on the motor operating data collected during the torque output process, the transmission system parameters to be measured are determined. This achieves the measurement of transmission system parameters after vehicle components are installed, effectively improving the measurement efficiency and accuracy of mechanical clearance parameters and half-shaft stiffness parameters. The aforementioned tooth-closed state can refer to the tooth surfaces of the driving gear and driven gear being in contact with each other, and the aforementioned installation can refer to all vehicle components being assembled into a complete vehicle.

[0060] It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, such as an in-vehicle electronic control unit, a vehicle controller, or an electronic device capable of performing the above functions. The following description uses a vehicle transmission system parameter measuring device (hereinafter referred to as the measuring device) as an example to illustrate this embodiment and the subsequent embodiments.

[0061] It should be noted that the above measurement conditions can be used to determine whether to execute vehicle transmission system parameters, and the measurement conditions may include the vehicle being in a parked state.

[0062] It should be noted that controlling the vehicle motor to periodically output torque can be done by controlling the vehicle motor to periodically output alternating positive and negative torque, for example, by controlling the vehicle motor output torque based on a periodic triangular waveform of alternating positive and negative torque.

[0063] In some embodiments, the measuring device can control the vehicle motor to periodically output alternating positive and negative torque based on a positive and negative alternating symmetrical waveform. The waveform needs to be set to be positive and negative symmetrical to ensure that the torque crosses zero, thereby testing the transmission system's mechanical backlash. In addition, the waveform should not have abrupt changes (such as steps), as this will cause the transmission system waveform to oscillate, affecting the test accuracy. The waveform period should be set within a certain range. The waveform period should not be too short or too long. A short waveform period can suppress oscillations caused by rapid torque changes, especially oscillations caused by the transmission system crossing mechanical backlash when the torque crosses zero; however, the period should not be too long either, otherwise it may conflict with the vehicle's operating time, so an excessively long waveform period should also be avoided. The waveform amplitude should also be set within a certain range, neither too large nor too small. If the waveform amplitude is too small, the signal-to-noise ratio of the acquired signal will be low; however, it should not be too large either, otherwise, in the event of brake device performance degradation or damage, insufficient braking force may cause the wheels to rotate, leading not only to measurement failure but also to parking safety issues. For example, a square wave with an amplitude of 50 Nm (the maximum output capacity of the motor is 250 Nm) and a period of 20 seconds can be used as the torque output waveform.

[0064] Furthermore, to avoid accidents during the measurement process and improve its accuracy and safety, the measurement conditions must include at least one of the following:

[0065] The vehicle is in a parked state, and the parking duration of the vehicle has reached a preset duration threshold, and the total mileage of the vehicle has exceeded a preset mileage threshold.

[0066] The vehicle is in a parked state, and the parking duration of the vehicle reaches a preset time threshold, and the total driving time of the vehicle exceeds a preset driving time threshold.

[0067] It should be noted that the measuring device can determine whether a vehicle has been parked for an extended period by setting a time threshold. For example, if a 10-minute time threshold is set, the measurement conditions are met when the vehicle has been parked for 10 minutes, and the measurement of the vehicle's transmission system parameters will begin.

[0068] Understandably, the purpose of setting measurement conditions to determine whether the parking duration has reached the preset time threshold is to ensure that the vehicle is unlikely to be started and used in the future. The longer this time is, the lower the probability that the vehicle will be used by the user in the future.

[0069] It should be noted that the preset mileage threshold can be used to determine whether the vehicle's total mileage has reached a certain stage, thereby avoiding frequent and unnecessary repeated measurements. Similarly, the aforementioned preset driving time threshold can be used to detect whether the vehicle's running time has reached a certain stage, thereby avoiding frequent and unnecessary repeated measurements.

[0070] Step S20: Measure the parameters of the vehicle's transmission system based on the motor operation data collected during the torque output process of the vehicle motor.

[0071] It should be noted that the parameters of the transmission system to be tested include mechanical clearance parameters and half-shaft stiffness parameters.

[0072] Understandably, when an electric vehicle is parked, the tires are clamped by the braking system, and the motor is controlled to apply torque in this state, such as... Figure 3 Both the left and right wheels are clamped by the braking device, and the vehicle motor applies T. m Torque, change in motor rotor angle θ m The change in the half-shaft connecting the differential to the left wheel is k1, and the change in the half-shaft connecting the differential to the right wheel is k2. The gearbox mechanical clearance is α. Because the vehicle's parking brake torque is greater than the drive torque, the applied motor torque will not cause the wheels to rotate. However, due to the clearance in the gear pair and the elasticity of the half-shaft, this torque will cause the transmission gear pair to engage / disengage and deform the transmission half-shaft. Since the wheels do not rotate, the change in the motor rotor angle during this process is entirely composed of the gearbox clearance angle and the half-shaft torsional angle. Therefore, during the vehicle motor's torque output process, motor operating data can be collected, and based on this data, the mechanical clearance parameters and half-shaft stiffness parameters of the vehicle's transmission system can be measured and calculated.

[0073] In some embodiments, the measuring device can control the vehicle motor to stop outputting torque when the torque output cycle of the vehicle motor reaches a preset cycle. For example, after the vehicle motor has completed three cycles (e.g., 60 seconds), the applied torque is stopped, thereby ensuring the accuracy of the measurement results while avoiding affecting the normal use of the vehicle.

[0074] In some embodiments, if the vehicle is started before the torque output cycle of the vehicle motor reaches a preset cycle, the measuring device can control the output torque of the vehicle motor to recover to 0 Nm with a preset slope. Controlling the torque output based on the preset slope by the measuring device can prevent excessively rapid torque changes from causing oscillations in the vehicle's transmission system. The preset slope can be set based on the period and amplitude of the vehicle motor's periodic torque output process.

[0075] This embodiment measures the transmission system parameters of the vehicle by controlling the vehicle motor to periodically output torque when the vehicle meets the measurement conditions, including the vehicle being in a parked state. The measured parameters include mechanical clearance parameters and half-shaft stiffness parameters, based on the motor operation data collected during the torque output process. Because this invention controls the vehicle motor to periodically output torque while the vehicle is parked, the controlled torque output causes the gear pairs in the transmission system to be in a close-tooth state, and the half-shaft to deform. The measured transmission system parameters are then obtained based on the motor operation data collected during the torque output process. This allows for the measurement of transmission system parameters after vehicle components are installed, effectively improving the measurement efficiency and accuracy of mechanical clearance and half-shaft stiffness parameters.

[0076] refer to Figure 4 , Figure 4 This is a flowchart illustrating the second embodiment of the vehicle transmission system parameter measurement method of the present invention.

[0077] Based on the first embodiment described above, in this embodiment, the motor operating data includes the rotor angle data of the vehicle motor, and step S20 further includes:

[0078] Step S21: Determine the clearance angle and half-shaft torsion angle of the vehicle transmission system based on the rotor angle data collected during the torque output process of the vehicle motor.

[0079] It should be noted that the clearance angle can be the angle of the gear pair engagement / disengagement clearance in the gearbox of a vehicle's transmission system.

[0080] In some embodiments, the mechanical clearance angles of the gear pairs are obtained by weighted summation. There will be mechanical clearance between the two gears in each gear pair in the transmission system. The total clearance angle is the weighted summation of these mechanical clearances. This weighted value is determined by the gear transmission ratio.

[0081] It should be noted that during the process of the vehicle motor outputting torque, since the vehicle is in a parked state, although the wheels will not rotate with the torque output by the motor, the half-shaft in the transmission system will deform. Therefore, the torsion angle of the half-shaft can be the angle at which the half-shaft in the transmission system deforms and twists.

[0082] It should be noted that the rotor angle data can be the data collected during the torque output process of the vehicle motor, showing how the motor rotor angle changes with the torque output.

[0083] Furthermore, to improve measurement accuracy, step S21 above may include:

[0084] Step S211: Perform waveform separation on the rotor angle data collected during the torque output process of the vehicle motor to obtain gap data and stiffness data;

[0085] Step S212: Determine the clearance angle and half-shaft torsion angle of the vehicle transmission system based on the clearance data and the stiffness data.

[0086] It should be noted that the clearance data can be used to calculate the clearance angle of the gear pair, and the torsion data can be used to calculate the torsion angle of the transmission system half-shaft.

[0087] It should be noted that waveform separation can be achieved by separating clearance data (which can be used to obtain the clearance angle) and stiffness data (which can be used to obtain the half-shaft torsional angle) from the signal waveform corresponding to the acquired motor rotor angle data, as shown in the reference. Figure 6 , Figure 6 This is a schematic diagram of the rotor angle waveform of the motor during the output torque process of the vehicle motor. The part of the rotor angle waveform used to obtain the gap can be the waveform before and after vibration, and the part used to obtain the stiffness can be the waveform line segment.

[0088] It should be understood that when the vehicle is parked, the vehicle motor outputs torque. At this time, because the vehicle tires are clamped by the braking device, if the parking braking torque is greater than the driving torque, the torque applied by the vehicle motor will not cause the wheels to rotate. However, due to the backlash in the gear pair and the elasticity of the half-shaft, this torque will cause the transmission gear pair to engage / disengage and deform the transmission half-shaft. Since the wheels are not rotating, the change in the motor rotor angle during this process is entirely composed of the gearbox clearance angle and the half-shaft torsional angle. Therefore, the measuring equipment can separate the clearance data and stiffness data from the rotor angle data, calculate the clearance angle based on the clearance data, and calculate the half-shaft torsional angle based on the stiffness data.

[0089] Furthermore, in order to reduce measurement errors and improve measurement accuracy, step S212 above may include:

[0090] Acquire torque output data during the torque output process of the vehicle motor;

[0091] Based on the torque output data, determine the torque change information and torque zero-crossing moment information during the torque output process of the vehicle motor;

[0092] The clearance angle of the vehicle's transmission system is determined based on the zero-crossing time information and clearance data;

[0093] The torsional angle of the half-shaft in the vehicle's drivetrain is determined based on torque variation information and stiffness data.

[0094] It should be noted that, as Figure 5 and Figure 6 As shown, Figure 5 This is a schematic diagram of the torque output waveform of a vehicle motor. Figure 6 This diagram illustrates the rotor angle waveform of a vehicle motor during torque output. When the vehicle is parked, the motor outputs alternating positive and negative torque. When the motor torque crosses zero, the rotor angle experiences a brief jump accompanied by oscillation. This oscillation can be represented by the noise lines in the rotor angle waveform diagram. This occurs during the gearbox clearance angle transition, and the parameter value causing the rotor angle jump can be the mechanical clearance value.

[0095] It should be understood that, in order to avoid the influence of oscillations generated when the gearbox passes through the clearance on the clearance calculation, this embodiment can take two points near the oscillation position on the rotor angle waveform (i.e., before and after the clearance) for reference. Figure 7 ,like Figure 7 Points a, b, c, and d are shown in the diagram; these are all calculation points. Figure 7 This is a schematic diagram for calculating the points on the rotor angle waveform. Figure 7 The points in the diagram are used to calculate the transmission system parameters. Then, the line formed by the two points is extended to the moment when the torque crosses zero. Figure 7 Extend lines a, b, c, and d to the moment the torque crosses zero. At this moment, the distance between two points on the extended lines is Δθ. m The distance Δθ between the two points m As the corresponding gap angle, refer to Figure 8 , Figure 8 To illustrate the spacing between the extended lines of the points, the extensions of points a and b, and c and d, are extended to the moment when the torque crosses zero. The distance between two points on the extension lines at the moment of zero crossing corresponds to the gap angle Δθ. m The moment when the torque crosses zero corresponds to the moment when the waveform begins to step in the rotor angle waveform diagram, and to the moment when the waveform crosses zero in the output torque waveform diagram.

[0096] In some embodiments, to avoid the impact of factors such as half-shaft torsional damping and quantization sampling noise on measurement accuracy, the amplitude and period of the torque output waveform of the vehicle motor should be controlled within a certain range. Excessive or insufficient period and amplitude will affect measurement accuracy. Therefore, the amplitude and period range of the motor torque output can be preset based on vehicle parameters. Furthermore, Figure 7The points shown above are for illustrative purposes only. Other points on the rotor angle waveform can also be used to calculate the half-shaft stiffness and mechanical clearance. This embodiment does not limit this. In some embodiments, multiple measurements can be taken and the average value can be calculated to improve the measurement accuracy.

[0097] In some embodiments, controlling the vehicle motor to periodically output torque can be achieved by outputting a symmetrical waveform with alternating positive and negative values. The waveform must be symmetrical to ensure the torque crosses zero, thus allowing testing of the transmission system's mechanical backlash. Furthermore, the waveform should not have abrupt changes (such as step jumps), as these can cause oscillations in the transmission system waveform, affecting test accuracy. The waveform period should be long enough to suppress oscillations caused by rapid torque changes, especially those resulting from the transmission system crossing mechanical backlash when the torque crosses zero; however, the period should not be too long, otherwise it may conflict with vehicle usage time. The waveform amplitude should be large enough to avoid low signal-to-noise ratios in the acquired signal, but it should not be too large either, otherwise, in the event of brake system performance degradation or damage, insufficient braking force may cause wheel rotation, leading not only to measurement failure but also parking safety issues. For example, a square wave with an amplitude of 50 Nm (the motor's maximum output capacity is 250 Nm) and a period of 20 seconds can be used as the torque output waveform.

[0098] Step S22: Determine the vehicle's mechanical clearance parameters and half-shaft stiffness parameters based on the clearance angle and half-shaft torsion angle.

[0099] It should be understood that since gearbox clearance and half-shaft torsion do not occur simultaneously, the clearance angle and half-shaft torsion angle can be separated from the signal in the motor rotor angle data at this time, and then the mechanical clearance and half-shaft stiffness can be calculated.

[0100] In some embodiments, the measuring device can measure the vehicle half-shaft stiffness parameters and mechanical clearance parameters according to the following steps:

[0101] Step 1: Determine whether the vehicle meets the measurement conditions, which include, but are not limited to: the vehicle is in a parked state, the parking duration of the vehicle reaches a preset duration threshold, and the total mileage of the vehicle exceeds a preset mileage threshold; the vehicle is in a parked state, the parking duration of the vehicle reaches a preset duration threshold, and the total mileage of the vehicle exceeds a preset driving time threshold.

[0102] Step 2: If the vehicle has been parked for more than the preset time and the total mileage exceeds the preset mileage threshold, or the total driving time exceeds the preset driving time threshold, then control the vehicle motor to apply a triangular wave torque starting from 0 Nm. The triangular wave period is 20 seconds, and the triangular wave amplitude is 50 Nm. When the applied torque is +10 Nm, -10 Nm, +40 Nm–40 Nm, record the corresponding rotor angle of the motor.

[0103] Step 3: After the vehicle motor torque output cycle has been completed for three cycles (e.g., 60 seconds), control the vehicle motor to stop outputting torque. If the vehicle starts before the three cycles are completed, control the motor to apply torque at a certain slope to restore 0 Nm.

[0104] Step 4: Acquire the operating data during the vehicle motor torque output process (such as motor rotor angle data and motor torque output data), separate the clearance data that can be used to calculate mechanical clearance and the stiffness data that can be used to calculate half-shaft stiffness from the operating data, and then measure the vehicle's mechanical clearance and half-shaft stiffness based on the clearance data and stiffness data respectively.

[0105] Furthermore, in order to accurately calculate the mechanical clearance and half-shaft stiffness, step S22 above may include:

[0106] Obtain the vehicle's gear ratio parameters;

[0107] The mechanical clearance parameters of the vehicle are determined based on the transmission ratio parameters and clearance angle.

[0108] Acquire torque change information during the torque output process of the vehicle motor;

[0109] Information on the change of the motor rotor during the torque output process of the vehicle motor is obtained based on the motor rotor angle parameters;

[0110] The axle stiffness parameters of the vehicle are determined based on torque variation information, motor rotor variation information, and axle torsional angle.

[0111] It should be noted that before and after the clearance, the gear pair is in a close-tooth state. The measuring equipment can calculate the mechanical clearance parameter based on the vehicle's transmission ratio parameter and the clearance angle using the following formula, where i is the transmission ratio parameter, α is the mechanical clearance parameter, and Δθ is the mechanical clearance parameter. m This represents the change in the motor rotor angle corresponding to the mechanical clearance.

[0112] α=Δθ m / i

[0113] The change in motor rotor angle caused by the torque applied when the gear pair is in a tooth-closed state originates from the torsion of the left and right half-shafts. Assume the motor torque change ΔT m Corresponding to the change in motor rotor angle Δθ m Based on the characteristics of the reducer and differential, let's assume the stiffness of the left and right half-shafts is k. L k R Then k L k R The following formula relationship is satisfied:

[0114]

[0115] If the difference in stiffness between the left and right half-shafts is negligible, then the stiffness of the left and right half-shafts can be calculated using the following formula:

[0116]

[0117] It should be understood that the calculation of half-shaft stiffness can be based on, for example... Figure 9 The calculations for points a and b shown are as follows: Figure 9 This is a waveform diagram of the motor rotor angle. Figure 10 The waveform diagram shows the motor torque output. Figure 9 The time corresponding to points a and b in the diagram Figure 10 Points e and f in the motor torque output waveform diagram are shown, where points a and e are points on different waveform diagrams at the same time, and points b and f are points on different waveform diagrams at the same time. The motor torque change ΔT m The calculation is based on the following formula, ΔΤ m This represents the change in motor torque between points e and f.

[0118] ΔT m =T m (f)-T m (e)

[0119] Motor rotor angle change Δθ m The calculation is based on the following formula, Δθ m This represents the change in the motor rotor angle between points a and b.

[0120] Δθ m =θ m (b)-θ m (a)

[0121] This embodiment determines the clearance angle and half-shaft torsion angle of the vehicle transmission system based on the rotor angle data collected during the torque output process of the vehicle motor. Based on the clearance angle and the half-shaft torsion angle, the mechanical clearance parameters and half-shaft stiffness parameters of the vehicle are determined, thereby realizing the decomposition of the collected data and effectively improving the measurement accuracy of the mechanical clearance parameters and half-shaft stiffness parameters.

[0122] Furthermore, embodiments of the present invention also propose a computer-readable storage medium storing a vehicle transmission system parameter measurement program, wherein when the vehicle transmission system parameter measurement program is executed by a processor, it implements the steps of the vehicle transmission system parameter measurement method described above.

[0123] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0124] The aforementioned computer-readable storage medium may be included in the vehicle powertrain parameter measuring device; or it may exist independently and not be assembled into the vehicle powertrain parameter measuring device.

[0125] In addition, to achieve the above objectives, this application also proposes an electric vehicle, which includes the vehicle drivetrain parameter measuring device as described above.

[0126] Furthermore, this invention also proposes a computer program product, including a vehicle transmission system parameter measurement program, which, when executed by a processor, implements the steps of the vehicle transmission system parameter measurement method described above.

[0127] The specific implementation of the computer program product of the present invention is basically the same as the embodiments of the above-described vehicle transmission system parameter measurement method, and will not be repeated here.

[0128] Reference Figure 11 , Figure 11 This is a structural block diagram of the first embodiment of the vehicle transmission system parameter measuring device of the present invention.

[0129] like Figure 11 As shown, the vehicle transmission system parameter measuring device proposed in this embodiment of the invention includes:

[0130] The motor control module 10 is used to control the vehicle motor to periodically output torque when the vehicle meets the measurement conditions, including the vehicle being in a parked state.

[0131] The parameter measurement module 20 is used to measure the parameters of the vehicle's transmission system under test based on the motor operation data collected during the torque output process of the vehicle motor. The parameters of the transmission system under test include mechanical clearance parameters and half-shaft stiffness parameters.

[0132] Furthermore, the parameter measurement module 20 is also used to determine the clearance angle and half-shaft torsion angle of the vehicle transmission system based on the rotor angle data collected during the torque output process of the vehicle motor; and to determine the mechanical clearance parameters and half-shaft stiffness parameters of the vehicle based on the clearance angle and half-shaft torsion angle.

[0133] Furthermore, the parameter measurement module 20 is also used to perform waveform separation on the rotor angle data collected during the torque output process of the vehicle motor to obtain clearance data and stiffness data; and to determine the clearance angle and half-shaft torsional angle of the vehicle transmission system based on the clearance data and stiffness data.

[0134] Furthermore, the parameter measurement module 20 is also used to acquire torque output data during the torque output process of the vehicle motor; determine torque change information and torque zero-crossing moment information during the torque output process of the vehicle motor based on the torque output data; determine the clearance angle of the vehicle transmission system based on the zero-crossing moment information and clearance data; and determine the half-shaft torsion angle of the vehicle transmission system based on the torque change information and stiffness data.

[0135] Furthermore, the parameter measurement module 20 is also used to acquire the vehicle's transmission ratio parameters; determine the vehicle's mechanical clearance parameters based on the transmission ratio parameters and the clearance angle; acquire torque change information during the torque output process of the vehicle motor; acquire motor rotor change information during the torque output process of the vehicle motor based on the motor rotor angle parameters; and determine the vehicle's half-shaft stiffness parameters based on the torque change information, motor rotor change information, and half-shaft torsional angle.

[0136] Furthermore, the measurement conditions include at least one of the following:

[0137] The vehicle is in a parked state, and the parking duration of the vehicle has reached a preset duration threshold, and the total mileage of the vehicle has exceeded a preset mileage threshold.

[0138] The vehicle is in a parked state, and the parking duration of the vehicle reaches a preset time threshold, and the total driving time of the vehicle exceeds a preset driving time threshold.

[0139] This embodiment measures the transmission system parameters by controlling the vehicle motor to periodically output torque when the vehicle meets the measurement conditions, including the vehicle being parked. The measured parameters include mechanical clearance parameters and half-shaft stiffness parameters, based on the motor operation data collected during the torque output process. Because this invention controls the vehicle motor to periodically output torque while the vehicle is parked, the controlled torque output causes the gear pairs in the transmission system to be in a close-tooth state, and the half-shaft to deform. By measuring the transmission system parameters based on the motor operation data collected during the torque output process, this invention enables the measurement of transmission system parameters after vehicle components are installed, effectively improving the measurement efficiency and accuracy of mechanical clearance and half-shaft stiffness parameters.

[0140] The vehicle transmission system parameter measuring device provided in this application, employing the vehicle transmission system parameter measuring method in the above embodiments, can solve the technical problem of vehicle transmission system parameter measurement. Compared with the prior art, the beneficial effects of the vehicle transmission system parameter measuring device provided in this application are the same as those of the vehicle transmission system parameter measuring method provided in the above embodiments, and other technical features in the vehicle transmission system parameter measuring device are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0141] It should be understood that the above are merely illustrative examples and do not constitute any limitation on the technical solutions of the present invention. In specific applications, those skilled in the art can make settings as needed, and the present invention does not impose any restrictions on this.

[0142] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of this invention. In practical applications, those skilled in the art can select some or all of the workflow to achieve the purpose of this embodiment according to actual needs, and no restrictions are imposed here.

[0143] In addition, for technical details not described in detail in this embodiment, please refer to the vehicle transmission system parameter measurement method provided in any embodiment of the present invention, which will not be repeated here.

[0144] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0145] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0146] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as read-only memory / random access memory, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0147] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A method for measuring parameters of a vehicle transmission system, characterized in that, The method for measuring vehicle powertrain parameters includes: When the vehicle meets the measurement conditions, the vehicle motor is controlled to periodically output torque, the measurement conditions including the vehicle being in a parked state; The parameters of the vehicle's transmission system to be tested are measured based on the motor operation data collected during the torque output process of the vehicle motor. The parameters of the transmission system to be tested include mechanical clearance parameters and half-shaft stiffness parameters.

2. The method for measuring vehicle transmission system parameters as described in claim 1, characterized in that, The motor operating data includes the rotor angle data of the vehicle motor; the measurement of the vehicle's transmission system parameters based on the motor operating data collected during the torque output process of the vehicle motor includes: The clearance angle and half-shaft torsion angle of the vehicle transmission system are determined based on the rotor angle data collected during the torque output process of the vehicle motor. The mechanical clearance parameters and axle stiffness parameters of the vehicle are determined based on the clearance angle and the axle torsion angle.

3. The method for measuring vehicle transmission system parameters as described in claim 2, characterized in that, The determination of the clearance angle and half-shaft torsion angle of the vehicle transmission system based on the rotor angle data collected during the torque output process of the vehicle motor includes: Waveform separation is performed on the rotor angle data collected during the torque output process of the vehicle motor to obtain gap data and stiffness data; The clearance angle and half-shaft torsion angle of the vehicle transmission system are determined based on the clearance data and the stiffness data.

4. The method for measuring vehicle transmission system parameters as described in claim 3, characterized in that, Determining the clearance angle and half-shaft torsion angle of the vehicle transmission system based on the clearance data and stiffness data includes: Acquire torque output data during the torque output process of the vehicle motor; Based on the torque output data, determine the torque change information and torque zero-crossing moment information during the torque output process of the vehicle motor; The clearance angle of the vehicle transmission system is determined based on the zero-crossing time information and the clearance data; The torsional angle of the half-shaft of the vehicle drivetrain is determined based on the torque variation information and the stiffness data.

5. The method for measuring vehicle transmission system parameters as described in claim 4, characterized in that, The process of determining the mechanical clearance parameters and axle stiffness parameters of the vehicle based on the clearance angle and the axle torsion angle includes: Obtain the transmission ratio parameters of the vehicle; The mechanical clearance parameters of the vehicle are determined based on the transmission ratio parameters and the clearance angle. Obtain torque change information during the torque output process of the vehicle motor; The information on the change of the motor rotor during the torque output process of the vehicle motor is obtained based on the motor rotor angle parameters. The axle stiffness parameters of the vehicle are determined based on the torque change information, the motor rotor change information, and the axle torsion angle.

6. The method for measuring vehicle transmission system parameters as described in any one of claims 1 to 5, characterized in that, The measurement conditions include at least one of the following: The vehicle is in a parked state, the parking duration of the vehicle reaches a preset duration threshold, and the total mileage of the vehicle exceeds a preset mileage threshold. The vehicle is in a parked state, the parking duration of the vehicle reaches a preset duration threshold, and the total driving time of the vehicle exceeds a preset driving time threshold.

7. A vehicle transmission system parameter measuring device, characterized in that, The vehicle transmission system parameter measuring device includes: The motor control module is used to control the vehicle motor to periodically output torque when the vehicle meets the measurement conditions, the measurement conditions including the vehicle being in a parked state; The parameter measurement module is used to measure the parameters of the vehicle's transmission system to be tested based on the motor operation data collected during the torque output process of the vehicle motor. The parameters of the transmission system to be tested include mechanical clearance parameters and half-shaft stiffness parameters.

8. A vehicle transmission system parameter measuring device, characterized in that, The vehicle drivetrain parameter measuring device includes: a memory, a processor, and a vehicle drivetrain parameter measuring program stored in the memory and executable on the processor, wherein the vehicle drivetrain parameter measuring program is configured to implement the vehicle drivetrain parameter measuring method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a vehicle powertrain parameter measurement program, which, when executed by a processor, implements the vehicle powertrain parameter measurement method as described in any one of claims 1 to 6.

10. An electric vehicle, characterized in that, The electric vehicle includes the vehicle drivetrain parameter measuring device as described in claim 8.

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