Method and device for determining torque capacity of wet clutch, vehicle terminal and storage medium

Abstract

The application provides a wet clutch torque capacity determination method and device, a vehicle-mounted terminal and a storage medium, and relates to the technical field of clutches. The method comprises the following steps: using the existing first motor and second motor and the speed sensors thereof, without disassembling the wet clutch or adding an additional torque sensor, the calibration can be completed in the gearbox assembly environment, the torque capacity is indirectly obtained by actively causing the slip, and then the torque capacity map is calibrated, so that the accuracy of the generated torque capacity map is higher than that of the map obtained by the traditional test; the second motor is used for real-time torque compensation during the calibration process, the negative impact of the engine torque unloading transmitted to the wheels is offset, and the driving performance of the whole vehicle is not affected, and the test result is closer to the actual working condition.

Description

Technical Field

[0001] This application relates to the field of clutch technology, and in particular to a method, device, vehicle terminal and storage medium for determining the torque capacity of a wet clutch. Background Technology

[0002] As a key actuator in hybrid powertrain systems, the wet clutch's torque-pressure map (a graph showing the relationship between torque capacity and wet clutch control pressure) is fundamental to the precise control of the hybrid transmission. The accuracy of the torque-pressure map directly affects the smoothness and response speed of the engine's direct drive process in hybrid mode, as well as the reliability of the wet clutch.

[0003] Currently, the main methods for obtaining torque-pressure maps are: bench testing, which requires disassembling the wet clutch and cannot reflect real-world operating conditions; and vehicle / assembly calibration, which focuses on pressure control or towing tests and does not systematically obtain the map. Therefore, these technologies are all difficult to calibrate torque-pressure maps efficiently and accurately. Summary of the Invention

[0004] Therefore, it is necessary to provide a method, device, vehicle terminal, and storage medium for determining the torque capacity of a wet clutch to address the aforementioned technical problems and obtain an accurate torque-pressure map.

[0005] In a first aspect, embodiments of this application provide a method for determining the torque capacity of a wet clutch, applied to a dual-motor hybrid transmission. The dual-motor hybrid transmission includes a wet clutch, a first motor, and a second motor. The first motor is connected to the input end of the wet clutch, and the second motor is connected to the output end of the wet clutch. The method includes: adjusting the input torque of the wet clutch to a zero torque state; continuously controlling the pressure of the wet clutch to a preset pressure value; increasing the output torque of the first motor based on a preset torque change rate, and controlling the second motor to compensate for torque; monitoring the speed difference between the first motor and the second motor in real time; and determining the torque capacity based on the speed difference. The torque capacity characterizes the maximum static friction torque that the wet clutch can transmit under the preset pressure value.

[0006] Using the above method, the existing first and second motors and their speed sensors in the hybrid system can be used to complete the calibration in the environment of the transmission assembly without disassembling the wet clutch or adding an additional torque sensor. This fully considers the actual lubrication circuit, temperature field and other operating conditions, making the accuracy of the generated torque capacity spectrum higher than that obtained by traditional tests. By supplementing torque in real time during the calibration process by the second motor, the negative impact of the engine torque unloading transmitted to the wheels is offset, ensuring that the drivability of the whole vehicle is not affected, and the test results are closer to the actual operating conditions.

[0007] In some embodiments, the preset pressure value is greater than the half-engagement point pressure value, which includes the minimum pressure value required to move the wet clutch piston to the contact friction plate by applying the target thrust. Determining the target thrust includes: real-time monitoring of the torque feedback value of the second motor, and when the torque feedback value of the second motor changes by a preset amplitude relative to the initial reference value, determining that the thrust applied to the wet clutch is the target thrust.

[0008] The above method ensures that the wet clutch has established a basic clamping force, providing a repeatable initial benchmark for subsequent linear loading and slippage testing, and improving the technical problem of invalid or uncontrollable slippage occurring at the beginning of the test.

[0009] In some embodiments, the half-engagement point pressure value is determined as follows: the first motor is controlled to be locked, and the second motor is controlled to operate at a preset speed; the pressure of the wet clutch is controlled to start from zero and increase in preset steps; the torque feedback value that shows a preset amplitude jump is recorded as the target torque value, and the wet clutch pressure corresponding to the target torque value is used as the half-engagement point pressure value.

[0010] The above methods effectively reduce system friction fluctuations and interference from human judgment, ensuring the consistency and accuracy of the obtained semi-contact point pressure values.

[0011] In some embodiments, adjusting the input torque at the front end of the wet clutch to a zero torque state includes: controlling the engine output torque to drop to zero to obtain an engine torque reduction value, the engine torque reduction value representing the amount of torque change in reducing the engine output torque from the initial torque to zero torque; controlling the first motor to output a preset negative torque to suppress the residual torque of the engine and the first motor, the residual torque representing the torque generated due to inertia or friction after the engine torque drops to zero; calculating a compensation torque based on the engine torque reduction value, controlling the second motor to output the compensation torque to suppress negative impact and zero the torque of the wet clutch; wherein, the negative impact includes the negative torque transmitted to the wheels during the torque suppression process, and the compensation torque is positively correlated with the amount of engine torque reduction.

[0012] The above method establishes a clear and repeatable initial zero point for subsequent wet clutch pressure calibration and torque loading, improves the uncertainty caused by residual torque on the engine and first motor side, and ensures that the active part of the wet clutch enters the test process under no-load conditions, thereby reducing the interference of residual torque on slip point detection and torque capacity judgment.

[0013] In some embodiments, determining the torque capacity based on the speed difference includes: determining whether the speed difference increases from zero and is greater than a preset slippage threshold; if the speed difference is greater than the slippage threshold, determining that the wet clutch is slipping and recording the output torque value of the first motor; and using the output torque value of the first motor as the torque capacity of the wet clutch under a preset pressure value.

[0014] By utilizing the existing sensor resources of the hybrid system, high-precision and high-consistency online calibration can be achieved without the need for additional hardware, while providing accurate data support for subsequent wet clutch control and shifting strategies.

[0015] In some embodiments, the method further includes: traversing preset pressure values ​​to obtain multiple sets of calibration data, the calibration data including preset pressure values ​​and corresponding initial torque capacity; performing outlier removal processing on the multiple sets of calibration data; performing piecewise linear interpolation on the calibration data after outlier removal to generate calibration data to be verified, the calibration data to be verified including fitted torque; and performing accuracy verification on the calibration data to be verified to obtain the torque capacity spectrum, the torque capacity spectrum including the correspondence between the preset pressure values ​​and the torque capacity.

[0016] The above method effectively filters out abnormal points caused by measurement noise or external interference during the calibration process, while ensuring that the overall error of the spectrum is controlled within the preset threshold. This provides accurate data reference for the real-time pressure control of the wet clutch, ensuring the accuracy and smoothness of torque transmission of the wet clutch under different operating conditions.

[0017] In some embodiments, the accuracy verification of the calibration data to be verified includes: calculating the absolute error between the torque capacity and the fitted torque, such that the absolute error is less than or equal to a first error threshold; calculating the relative error between the torque capacity and the fitted torque, such that the relative error is less than or equal to a second error threshold; verifying the maximum relative error, such that the maximum relative error is less than or equal to a third error threshold; and verifying the average relative error, such that the average relative error is less than or equal to a fourth error threshold.

[0018] The above methods can comprehensively identify outliers and systematic deviations in calibration data, effectively verify the engineering usability of the graphs across the entire pressure range, and thus provide a high-confidence control benchmark for the transmission control unit.

[0019] Secondly, embodiments of this application provide a wet clutch torque capacity determination device, comprising: a clutch torque clearing module, used to adjust the input torque of the wet clutch to a zero torque state and continuously control the wet clutch pressure to a preset pressure value; a motor control module, used to increase the output torque of a first motor based on a preset torque change rate and control a second motor to compensate for torque; and a torque capacity determination module, used to monitor the speed difference between the first motor and the second motor in real time and determine the torque capacity based on the speed difference, wherein the torque capacity characterizes the maximum static friction torque that the wet clutch can transmit under the preset pressure value.

[0020] In some embodiments, the torque capacity determination module is used to monitor the torque feedback value of the second motor in real time. When the torque feedback value of the second motor changes by a preset amplitude relative to the initial reference value, the thrust applied to the wet clutch is determined to be the target thrust.

[0021] In some embodiments, the motor control module is used to control the first motor to be in a locked state, control the second motor to operate at a preset speed, control the pressure of the wet clutch to increase from zero in preset steps, record the torque feedback value that shows a preset amplitude jump as the target torque value, and use the wet clutch pressure corresponding to the target torque value as the half-engagement point pressure value.

[0022] In some embodiments, the clutch torque clearing module is used to control the engine output torque to drop to zero, obtaining an engine torque reduction value, which represents the amount of torque change required to reduce the engine output torque from the initial torque to zero torque; control the first motor to output a preset negative torque to suppress the residual torque of the engine and the first motor, whereby the residual torque represents the torque generated due to inertia or friction after the engine torque drops to zero; calculate a compensation torque based on the engine torque reduction value, and control the second motor to output the compensation torque to suppress negative impact and clear the torque of the wet clutch to zero; wherein, the negative impact includes the negative torque transmitted to the wheels during the torque suppression process, and the compensation torque is positively correlated with the amount of engine torque reduction.

[0023] In some embodiments, the torque capacity determination module is used to determine whether the speed difference increases from zero and is greater than a preset slippage threshold; if the speed difference is greater than the slippage threshold, it is determined that the wet clutch has slipped and the output torque value of the first motor is recorded; the output torque value of the first motor is used as the torque capacity of the wet clutch under a preset pressure value.

[0024] In some embodiments, the wet clutch torque capacity determination device further includes a spectrum generation module, which is used to traverse preset pressure values ​​to obtain multiple sets of calibration data, the calibration data including preset pressure values ​​and corresponding initial torque capacity; perform outlier removal processing on the multiple sets of calibration data; perform piecewise linear interpolation on the calibration data after removing outliers to generate calibration data to be verified, the calibration data to be verified including fitted torque; and perform accuracy verification on the calibration data to be verified to obtain a torque capacity spectrum.

[0025] In some embodiments, the map generation module is further configured to calculate the absolute error between the torque capacity and the fitted torque, such that the absolute error is less than or equal to a first error threshold; and to calculate the relative error between the torque capacity and the fitted torque, such that the relative error is less than or equal to a second error threshold; and to verify the maximum relative error, such that the maximum relative error is less than or equal to a third error threshold; and to verify the average relative error, such that the average relative error is less than or equal to a fourth error threshold.

[0026] Thirdly, embodiments of this application provide an in-vehicle terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the first aspect and any possible implementation method.

[0027] Fourthly, embodiments of this application provide a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method of the first aspect and any possible implementation.

[0028] The beneficial effects of this application are as follows: This application proposes a method, device, vehicle terminal, and storage medium for determining the torque capacity of a wet clutch. By utilizing the existing first and second motors and their speed sensors in the hybrid system, calibration can be completed in the environment of the transmission assembly without disassembling the wet clutch or adding an additional torque sensor. The torque capacity is indirectly obtained by actively creating slippage, and then a torque capacity spectrum is obtained through calibration, making the accuracy of the generated torque capacity spectrum higher than that obtained by traditional tests. By supplementing torque in real time during the calibration process by the second motor, the negative impact of engine torque unloading transmitted to the wheels is offset, ensuring that the drivability of the vehicle is not affected, and the test results are closer to the actual working conditions. Attached Figure Description

[0029] 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, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0030] Figure 1 A schematic diagram of a wet clutch torque capacity determination architecture provided in an embodiment of this application; Figure 2 A flowchart illustrating a method for determining the torque capacity of a wet clutch, as provided in an embodiment of this application; Figure 3 A flowchart of a control method for automatic calibration of the torque capacity of a wet clutch provided in this application embodiment; Figure 4 A schematic diagram of a wet clutch torque capacity determination device provided in an embodiment of this application; Figure 5 This is a schematic diagram of the internal structure of a vehicle-mounted terminal provided in an embodiment of this application. Detailed Implementation

[0031] 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.

[0032] 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.

[0033] To facilitate understanding of the technical solutions provided in the embodiments of this application, the design concept of the embodiments of this application will be introduced first below: The wet clutch is a key component in a dual-motor hybrid architecture. In this architecture, it is typically located between the engine and the transmission, used to couple and decouple the engine from the drive motor. The torque-pressure map is fundamental to the precise control of the hybrid transmission, directly impacting the smoothness and responsiveness of the engine's direct-drive operation in hybrid mode, as well as the reliability of the wet clutch. Therefore, obtaining an accurate and reliable torque-pressure map is a prerequisite for developing hybrid transmission control software and a core foundation for ensuring vehicle drivability and the lifespan of the wet clutch.

[0034] Currently, obtaining torque-pressure maps mainly relies on bench testing and vehicle or assembly calibration methods. Among these: Bench testing involves mounting the wet clutch assembly on a dedicated wet clutch performance test bench, providing precise pressure through an external hydraulic system, and directly measuring the transmitted torque of the wet clutch under different pressures using a high-precision torque sensor. However, this type of bench testing requires disassembling the wet clutch from the transmission assembly, and the test environment differs from the actual hybrid system (e.g., lubrication circuits, temperature field, vibration environment), thus failing to reflect the true operating condition of the wet clutch within the transmission assembly.

[0035] Vehicle / engineering calibration methods involve indirectly obtaining torque capacity by controlling the wet clutch pressure and observing the system response on a hybrid transmission assembly bench or in a complete vehicle. This method focuses on real-time pressure regulation during the control process and does not address how to systematically obtain the torque-pressure map. Calibration on a transmission assembly bench typically requires the installation of additional torque sensors, which is not only costly but also space-constrained, and in some cases, impossible to install.

[0036] In summary, the relevant technologies have the following shortcomings: bench testing requires the wet clutch to be removed from the gearbox, which cannot take into account actual factors such as the internal lubrication circuit of the gearbox and the thermal effects of adjacent components, resulting in a deviation between the map and the actual working condition; additional torque sensors need to be installed when calibrating the gearbox assembly on the bench, which is costly and has limited installation space.

[0037] To address the shortcomings of the aforementioned related technologies, this application provides a wet clutch torque capacity calibration method that utilizes the inherent conditions of a dual-motor hybrid system, requires no additional sensors, and can be implemented online. The method leverages the advantages of dual-motor coordinated control by using a first motor for torque clearing and linear loading, and a second motor for locking and torque compensation. The second motor's real-time torque compensation counteracts the negative impact transmitted to the wheels from engine torque unloading, ensuring that the vehicle's drivability remains unaffected during calibration. This application eliminates the need to disassemble the wet clutch, performing calibration directly within the transmission assembly or vehicle environment. It fully considers actual lubrication circuits, temperature fields, system stiffness, and other factors, resulting in a higher Map accuracy than traditional bench tests. Furthermore, this application allows for periodic execution of this method during vehicle use, automatically correcting for changes in wet clutch characteristics caused by wear and aging, thus improving the long-term consistency of wet clutch control.

[0038] The following section provides a detailed description of the wet clutch torque capacity determination method, device, vehicle terminal, and storage medium proposed in this application: First, the test architecture of this application is introduced. In some embodiments, the wet clutch torque capacity determination method provided in this application, as an example, uses a generator P1 as the first motor and a drive motor P3 as the second motor, which can be applied to applications such as... Figure 1 In the test architecture shown. Figure 1 It includes a wet clutch, a generator P1, a drive motor P3, and an engine. The engine and generator P1 are rigidly connected to the crankshaft and serve as the power input terminals, located on one side of the wet clutch. The other side of the wet clutch is connected to the drive motor P3, which is connected to the output terminal of the gearbox and is used to drive the wheels.

[0039] Based on the above structure, dual-motor hybrid systems typically have pure electric mode, series mode, parallel mode, and engine direct drive mode. In pure electric mode, the wet clutch disengages, the engine and generator P1 do not operate, and only the drive motor P3 drives the vehicle. In series mode, the wet clutch disengages, the engine starts and drives the generator P1 to generate electricity to supply the battery or drive motor P3, which then drives the vehicle alone. In parallel mode, the wet clutch engages, and the engine and both motors drive the vehicle together. In kinetic energy recovery mode, the wet clutch disengages, and the wheels pull on the P3 motor to generate electricity and recover energy. In engine direct drive mode, the wet clutch is fully engaged, engine torque is transmitted to the transmission input shaft through the wet clutch, the generator P1 is in a follow-along state, and the drive motor P3 is connected to the transmission output.

[0040] Since the torque capacity of a wet clutch is the maximum static friction torque that the wet clutch can transmit under a given pressure, it is only meaningful when the wet clutch is engaged. In the disengaged state, the torque capacity is always 0, which cannot be measured or calibrated. Therefore, the torque capacity of a wet clutch must be engaged to be tested. Only in the engaged state do normal pressure and static friction exist between the driving part (engine and generator) and the driven part (transmission and drive motor) of the wet clutch, and only then can the static friction limit be measured by actively creating slippage.

[0041] As can be seen from the above description of the working modes of the dual-motor system, the engine direct drive mode is the most ideal calibration condition. In this mode, the wet clutch is fully engaged, and the engine direct drive mode is a single power source without dynamic interference from gear shifting or mode switching. The torque source is singular and easy to reset to zero, which can provide a stable basic condition for clutch calibration and ensure the accuracy and repeatability of slip point detection.

[0042] Furthermore, since the torque-pressure map obtained by this application describes the physical characteristics of the wet clutch itself, rather than the system response under a specific operating condition, the interference of other operating conditions affects the dynamic behavior of the system, rather than the physical capabilities of the wet clutch hardware itself. Therefore, the torque-pressure map calibrated by this application is applicable to the operating conditions of various wet clutches.

[0043] The following section provides a detailed description of the method for determining the torque capacity of a wet clutch proposed in this application: In some embodiments, such as Figure 2 As shown, a method for determining the torque capacity of a wet clutch is provided, which is then applied to... Figure 1 Taking the architecture in [the document] as an example, the following steps are included: Step S201: Adjust the input torque of the wet clutch to zero torque and continuously control the pressure of the wet clutch to the preset pressure value.

[0044] As discussed above, the engine direct drive mode is the ideal calibration condition. Although the engine direct drive mode is a single power source, due to the coupling effect of inertia, pumping losses, and frictional resistance, the engine does not achieve ideal zero torque output in the zero-command state. Therefore, it is necessary to actively apply a small negative torque through the P1 motor to clear the torque, absorb residual energy, and ensure the accuracy of the calibration reference.

[0045] In some embodiments, adjusting the input torque at the front end of the wet clutch to a zero torque state includes: controlling the engine output torque to drop to zero to obtain an engine torque reduction value, the engine torque reduction value representing the amount of torque change in reducing the engine output torque from the initial torque to zero torque; controlling the first motor to output a preset negative torque to suppress the residual torque of the engine and the first motor, the residual torque representing the torque generated due to inertia or friction after the engine torque drops to zero; calculating a compensation torque based on the engine torque reduction value, controlling the second motor to output the compensation torque to suppress negative impact and zero the torque of the wet clutch; wherein, the negative impact includes the negative torque transmitted to the wheels during the torque suppression process, and the compensation torque is positively correlated with the amount of engine torque reduction.

[0046] The above method establishes a clear and repeatable initial zero point for subsequent wet clutch pressure calibration and torque loading, improving the uncertainty caused by residual torque on the engine and first motor sides, ensuring that the active part of the wet clutch enters the test process under no-load conditions, thereby improving the technical problem of residual torque interfering with slip point detection and torque capacity judgment.

[0047] As an example, the first motor is a generator P1, and the second motor is a drive motor P3. Commands are sent to the engine and motor P1 via the vehicle controller or transmission control unit to reduce the engine torque to zero. Simultaneously, motor P1 is controlled to output zero torque or a small negative torque to eliminate residual engine torque, ensuring that the torque at the front end of the wet clutch (i.e., the active part of the wet clutch) is zero. This puts the wet clutch in an unloaded state, providing an initial zero point for subsequent pressure setting and loading, while motor P3 is controlled to compensate for torque loss, ensuring the vehicle's drivability.

[0048] However, during the torque clearing process, by reducing engine torque (engine torque unloading) and applying negative torque to the P1 motor to bring the front-end torque to zero, the load state of the transmission system is instantly changed, generating a drag force opposite to the direction of travel. If left unchecked, this impact will be transmitted to the wheels through the transmission, causing the vehicle to jerk, severely affecting the driving experience, and may even be misdiagnosed as a malfunction.

[0049] Engine torque unloading is the process by which the engine actively reduces its torque to zero from a state of outputting positive torque. When the engine torque suddenly drops, the transmission system loses its original driving force and generates a drag force in the opposite direction of travel, i.e., a negative impact.

[0050] Because the P3 motor is located at the gearbox output and directly connected to the wheels, when a negative impact occurs during torque compensation, the TCU (Transmission Control Unit) calculates the required compensation amount in real time and instructs the P3 motor to output a positive compensation torque. This positive torque mechanically cancels out the negative impact, so the wheels do not feel a drastic change in net torque. Through torque compensation, the calibration system can complete the front-end torque zeroing in a very short time, while ensuring that the occupants inside the vehicle can hardly detect it, achieving a balance between testing efficiency and driving comfort.

[0051] After establishing the initial zero point of the test system by clearing the torque, a preset pressure value is applied to the wet clutch, and the torque capacity is determined by detecting the speed difference between the master and slave parts of the wet clutch.

[0052] In some embodiments, the preset pressure value is greater than the half-engagement point pressure value, which includes the minimum pressure value required to move the wet clutch piston to the contact friction plate by applying the target thrust. Determining the target thrust includes: real-time monitoring of the torque feedback value of the second motor, and when the torque feedback value of the second motor changes by a preset amplitude relative to the initial reference value, determining that the thrust applied to the wet clutch is the target thrust.

[0053] The semi-engagement pressure value is the zero point of the torque transmission capability of a wet clutch. Only in the region where the pressure is greater than this value can a wet clutch generate stable and measurable static friction, thereby calibrating the effective torque capacity.

[0054] If the preset pressure value is less than the half-engagement point pressure value, the piston does not contact the friction plate and there is a gap. At this time, no matter how much torque the first motor applies, the wet clutch cannot transmit any force and will only idle. Therefore, the torque capacity cannot be measured at all.

[0055] If the preset pressure value is equal to the half-engagement point pressure value, the piston just contacts the friction plate, but the normal pressure is zero. At this time, the torque capacity of the wet clutch is theoretically zero, and the physical state is extremely unstable. Any slight disturbance will lead to misjudgment, the data cannot be repeated, and it cannot be used as a calibration starting point.

[0056] Only when the preset pressure value is greater than the half-engagement point pressure value will the piston begin to press against the friction plate, generating a stable positive pressure (target thrust). At this time, the wet clutch has a torque capacity greater than zero. By controlling the first motor to apply linear load, the critical point from zero slip to slip can be tested, thereby obtaining a stable and accurate torque capacity.

[0057] The above method ensures that the wet clutch has established a basic clamping force, providing a repeatable initial benchmark for subsequent linear loading and slippage testing, and improving the technical problem of invalid or uncontrollable slippage occurring at the beginning of the test.

[0058] The above analysis shows that the half-binding point pressure value is very important for spectrum calibration. Therefore, the more accurate the half-binding point pressure value, the more accurate the calibration result.

[0059] In some embodiments, the half-engagement point pressure value is determined as follows: the first motor is controlled to be locked, and the second motor is controlled to operate at a preset speed; the pressure of the wet clutch is controlled to start from zero and increase in preset steps; the torque feedback value that shows a preset amplitude jump is recorded as the target torque value, and the wet clutch pressure corresponding to the target torque value is used as the half-engagement point pressure value.

[0060] It can be seen that by locking the first motor and rotating the second motor at a constant speed, under the condition that the driving end of the wet clutch is fixed and the driven end is rotating, the piston displacement is triggered by gradually increasing the pressure. The instantaneous jump of the torque of the second motor is used as the physical criterion to transform the fuzzy node that depends on experience or indirect inference into a quantifiable and reproducible electrical detection signal. This allows for the accurate testing of the critical pressure value when the piston contacts the friction plate but has not yet generated a clamping force, providing a reliable reference zero point for subsequent torque capacity calibration.

[0061] The above methods effectively reduce system friction fluctuations and interference from human judgment, ensuring the consistency and accuracy of the obtained semi-contact point pressure values.

[0062] The above method yields a more accurate half-engagement point pressure value. Based on this, a preset pressure value applied to the wet clutch can be set, and point-by-point control can be performed in the calibrated dual-motor hybrid system. This allows for the generation of multiple sets of calibration data based on the speed difference, as detailed below:

[0063] Step S202: Increase the output torque of the first motor based on the preset torque change rate, and control the second motor to compensate for torque.

[0064] Because the first motor is connected to the input of the wet clutch, the output torque of the first motor is increased linearly during calibration. If the wet clutch has not slipped, this torque will be transmitted to the wheels through the wet clutch and the transmission, generating a positive force to drive the vehicle forward. Without intervention, the vehicle will suddenly accelerate, severely affecting the driving experience and even causing safety issues.

[0065] The second motor is located at the gearbox output and is directly connected to the wheels. Controlling the second motor to output a compensating torque that is equal in magnitude but opposite in direction to the torque transmitted by the first motor can completely cancel out the driving force generated by the first motor at a mechanical level. At this time, the net driving force at the wheels is zero, and the vehicle remains stationary or moves at a constant speed.

[0066] Therefore, by supplementing torque to keep the vehicle stable, it is equivalent to simulating the lock-up condition of bench testing in the whole vehicle environment, ensuring that the measured torque capacity truly reflects the physical characteristics of the wet clutch itself, and is not affected by the inertia of the whole vehicle.

[0067] Step S203: Monitor the speed difference between the first motor and the second motor in real time, and determine the torque capacity based on the speed difference. The torque capacity characterizes the maximum static friction torque that the wet clutch can transmit under a preset pressure value.

[0068] In some embodiments, determining the torque capacity based on the speed difference includes: determining whether the speed difference increases from zero and is greater than a preset slippage threshold; if the speed difference is greater than the slippage threshold, determining that the wet clutch is slipping and recording the output torque value of the first motor; and using the output torque value of the first motor as the torque capacity of the wet clutch under a preset pressure value, wherein the torque capacity characterizes the maximum static friction torque that the wet clutch can transmit under the preset pressure value.

[0069] By utilizing the existing sensor resources of the hybrid system, high-precision and high-consistency online calibration can be achieved without the need for additional hardware, while providing accurate data support for subsequent wet clutch control and shifting strategies.

[0070] As an example, the TCU module adjusts the wet clutch pressure to a preset target pressure value Pi, i=1,2,...,n, where n is the number of calibration points. During pressure build-up, the wet clutch piston moves and presses against the friction plates, but since there is no torque input at the front end, the wet clutch remains stationary and in a non-slipping state. The set target pressure needs to be above the half-engagement point pressure value, improving the technical problem of slippage occurring in the wet clutch before the P1 motor begins to load. The wet clutch pressure is kept constant at Pi, and the P1 motor is controlled to linearly increase the output torque at a preset torque change rate. Simultaneously, the P3 motor is controlled to provide torque compensation to ensure the vehicle's drivability.

[0071] The speed difference between the driving and driven parts of the wet clutch is monitored in real time. When the speed difference increases from zero and exceeds the preset slippage threshold, it is determined that the wet clutch has experienced slight slippage. At this time, the current torque value of motor P1 is recorded and mapped to the input torque T of the wet clutch. i This value represents the maximum static friction torque capacity that the wet clutch can transmit under the current pressure Pi. Simultaneously, the torque of the P1 motor is cleared, improving the technical problem of the wet clutch being in a state of constant slippage and reducing slippage work. Thus, multiple sets of calibration data (Pi, Ti) can be obtained without adding additional hardware.

[0072] In some embodiments, the method further includes: traversing preset pressure values ​​to obtain multiple sets of calibration data, the calibration data including preset pressure values ​​and corresponding initial torque capacity; performing outlier removal processing on the multiple sets of calibration data; performing piecewise linear interpolation on the calibration data after removing outliers to generate calibration data to be verified, the calibration data to be verified including fitted torque; and performing accuracy verification on the calibration data to be verified to obtain a torque capacity spectrum, the torque capacity spectrum including the correspondence between the preset pressure values ​​and the torque capacity.

[0073] The process of iterating through preset pressure values ​​includes, for each preset pressure value, executing the torque capacity determination method described in this application to obtain multiple sets of calibration data.

[0074] After traversing the preset pressure values, multiple sets of calibration data are obtained. Through outlier removal and piecewise linear interpolation, a torque-pressure map is generated and stored in the TCU for subsequent wet clutch control.

[0075] In one possible embodiment, multiple sets of calibration data can be obtained in the following way:

[0076] Set the pressure point sequence to be calibrated {P1, P2, …, P} n}, where the pressure in the pressure point sequence is greater than the pressure value of the half-bond point; initialize the pressure point index i = 1 (i is a positive integer); set the current target pressure value to P. i Perform the torque capacity determination method to obtain the torque capacity T at that pressure point. i This forms a set of calibration data (P) i , T i ); Determine if i is equal to n: If i < n, increment i by 1 and continue to the calibration of the next pressure point (execute the torque capacity determination method); If i = n, then all pressure points are calibrated and multiple sets of calibration data are obtained.

[0077] As an example, outlier removal is performed using the IQR (Interquartile Range Method), where points outside the specified interval are considered outliers and removed. Additionally, points where torque monotonically increases with pressure are also considered outliers. The resulting calibrated discrete Map nodes are: ( , ), ( , ), ..., ( , ), < <...< For any pressure First find the interval ∈[ , Then, the interpolation formula is obtained, which is used to calculate the corresponding torque capacity: ; in, For torque capacity, The current wet clutch pressure, For any point in the calibration interval, For the k-th calibration pressure, For the first The calibrated pressure of each, for The corresponding torque capacity, for The corresponding torque capacity.

[0078] The above method effectively filters out abnormal points caused by measurement noise or external interference during the calibration process, while ensuring that the overall error of the spectrum is controlled within the preset threshold. This provides accurate data reference for the real-time pressure control of the wet clutch, ensuring the accuracy and smoothness of torque transmission of the wet clutch under different operating conditions.

[0079] The torque capacity directly measured through slippage testing is a true physical measurement value, but this value only exists at discrete pressure points and cannot cover all operating conditions. Interpolated graphs make these discrete points continuous for real-time TCU lookup, but the interpolation process inevitably introduces fitting errors. Therefore, it is necessary to verify the error parameters between the fitted torque and torque capacity in the torque capacity graph, including: absolute error, relative error, maximum relative error, and average relative error. This improves the accuracy of the graph across the entire pressure range, ensures that the deviation between the graph output and the original measured data is controllable, and addresses the technical problem of wet clutch control commands being executed based on distorted data, thereby guaranteeing smooth shifting and torque transmission accuracy.

[0080] In some embodiments, the accuracy verification of the calibration data to be verified includes: calculating the absolute error between the torque capacity and the fitted torque, such that the absolute error is less than or equal to a first error threshold; calculating the relative error between the torque capacity and the fitted torque, such that the relative error is less than or equal to a second error threshold; verifying the maximum relative error, such that the maximum relative error is less than or equal to a third error threshold; and verifying the average relative error, such that the average relative error is less than or equal to a fourth error threshold.

[0081] As an example, the first error threshold can be 20 N / m (Newton-meter), the second error threshold can be 0.2, the third error threshold can be 0.2, and the fourth error threshold can be 0.2, so that the absolute error is ≤20 N / m, the relative error is ≤0.2, the maximum relative error is ≤0.2, and the average relative error is ≤0.2.

[0082] The absolute error directly reflects the absolute deviation between the output value of the graph and the measured value. Under high torque conditions (such as above 200 N / m), even if the relative error is small, the absolute deviation may still be large, affecting the accuracy of wet clutch control. Limiting the absolute error to ≤20 N / m ensures control accuracy during high torque transmission.

[0083] The relative error reflects the calibration accuracy under low torque conditions. Under low torque conditions (such as 50 N / m), the relative error is limited to ≤0.2, which can ensure the calibration accuracy under low torque conditions. This ensures the control accuracy of the wet clutch under low torque conditions such as starting and creeping, and improves the technical problem of uneven engagement caused by excessive relative deviation.

[0084] The maximum relative error reflects the point with the largest error among all calibration points. This indicator improves the situation where excessive calibration deviation at individual pressure points causes the vehicle to experience shocks or jerks under specific operating conditions. The average relative error reflects the overall accuracy level of the map. Even if the error at individual points is large, if the average value is acceptable, it indicates that the accuracy of most points is good; conversely, if the average value exceeds the standard, it indicates that there is a systematic deviation and recalibration is required.

[0085] The above methods can comprehensively identify outliers and systematic deviations in calibration data, effectively verify the engineering usability of the graphs across the entire pressure range, and thus provide a high-confidence control benchmark for the transmission control unit.

[0086] Finally, use the following formula to look up the table online: ; in, For torque capacity, This is the minimum torque capacity, typically 0. The maximum threshold value (maximum torque capacity) that a wet clutch can transmit. For the minimum calibrated pressure, The current wet clutch pressure, For the maximum calibrated pressure, For any point in the calibration interval, For the k-th calibration pressure, For the first The calibrated pressure of each, for The corresponding torque capacity, for The corresponding torque capacity. For example, when the TCU queries the torque capacity corresponding to P = 2.8 bar: first find the interval where P is located, assuming P∈[2.5,3.0], then k=2. =2.5, =80, =3.0, =104, substitute into the interpolation formula to calculate the torque capacity.

[0087] Based on the above introduction, Figure 3 This paper presents a control method for automatic calibration of wet clutch torque capacity. First, it determines whether the automatic control conditions for wet clutch torque capacity testing are met. For example, the automatic control trigger conditions for wet clutch torque capacity testing include: vehicle speed between (70, 100), acceleration between (-2, 2), accelerator pedal position between (10, 50), accelerator pedal change rate between (-200, 200), brake pedal false, no system faults (engine, motor, wet clutch, battery, etc.), steering wheel angle between (-10, 10), lateral acceleration between (-1, 1), GTA function enabled, and drive motor speed change rate between (-200, 200). Meeting one or more of these conditions is sufficient. After confirming that the automatic control conditions for wet clutch torque capacity testing are met, the paper first checks whether the vehicle status meets the calibration trigger conditions, including whether the engine is idling and running stably, whether the hydraulic oil temperature change rate is less than the threshold, and whether there is no vehicle mode switching operation. If the conditions are met, the calibration process begins; otherwise, it continues to wait.

[0088] After entering torque clearing control, the system sends a zero torque request to the engine via the HCU (Vehicle Controller Unit) or TCU, controlling the P1 motor to output zero torque or a small negative torque to eliminate residual torque at the front end of the wet clutch. Simultaneously, the P3 motor is controlled to compensate for torque loss to maintain drivability. The torque at the front end of the wet clutch is continuously monitored until it is less than 5 N / m, and the solenoid valve current is confirmed to reach 1300 mA (ensuring the hydraulic system is under control). Then, the system enters wet clutch pressure setpoint control. Adjust the wet clutch pressure to the preset target pressure value Pi (which must be greater than the half-engagement point pressure value) and maintain a constant pressure. The system monitors the actual pressure of the wet clutch in real time to determine whether it is within the target pressure ±0.2 bar range. If the accuracy requirement is not met, continue adjusting the pressure until it reaches the target. If the accuracy requirement is met, enter the wet clutch front-end torque increase control: The wet clutch pressure is kept constant at Pi, and the P1 motor is controlled to linearly increase the output torque at a preset torque change rate, while the speed difference between the driving and driven parts of the wet clutch is monitored in real time. When the speed difference increases from zero and exceeds the preset slippage threshold, the wet clutch is determined to be slipping.

[0089] Then, the torque value of the wet clutch front end under the current pressure is solidified. When slippage occurs, the torque value of the current P1 motor is recorded as the torque capacity Ti of the wet clutch under the pressure Pi, and this value is solidified and stored.

[0090] Finally, determine whether all pressure points have been scanned and check whether all preset pressure points have been traversed. If not, change the target pressure value and return to step two to continue calibrating the next pressure point; if all pressure points have been scanned, the calibration process ends and enters the generation and verification stage of the torque-pressure map.

[0091] The above method utilizes the existing first and second motors and their speed sensors in the hybrid system to complete calibration within the gearbox assembly environment without disassembling the wet clutch or adding an additional torque sensor. It indirectly obtains torque capacity by actively creating slippage, thereby calibrating a torque capacity spectrum, resulting in a higher accuracy than the spectrum obtained by traditional tests. By supplementing torque in real time during the calibration process with the second motor, the negative impact of engine torque unloading transmitted to the wheels is offset, ensuring that the drivability of the vehicle is not affected, and the test results are closer to actual operating conditions.

[0092] It should be understood that, although Figure 2 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 2 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0093] Based on the same inventive concept, this application provides a wet clutch torque capacity determination device 400, including: a clutch torque clearing module 401, a motor control module 402, a torque capacity determination module 403, and a graph generation module 404, wherein: The clutch torque clearing module 401 is used to adjust the input torque of the wet clutch to a zero torque state and continuously control the wet clutch pressure to a preset pressure value. The motor control module 402 is used to control the wet clutch pressure to remain constant at a preset pressure value, increase the output torque of the first motor based on a preset torque change rate, and control the second motor to compensate for torque. The torque capacity determination module 403 is used to monitor the speed difference between the first motor and the second motor in real time and determine the torque capacity based on the speed difference. The torque capacity represents the maximum static friction torque that the wet clutch can transmit under a preset pressure value.

[0094] In some embodiments, the preset pressure value is greater than the half-engagement point pressure value, and the half-engagement point pressure value includes the minimum pressure value required to apply the target thrust to move the wet clutch piston to the contact friction plate. Determining the target thrust includes: real-time monitoring of the torque feedback value of the second motor, and when the torque feedback value of the second motor changes by a preset amplitude relative to the initial reference value, determining that the thrust applied to the wet clutch is the target thrust.

[0095] In some embodiments, the motor control module 402 is used to control the first motor to be in a locked state, control the second motor to work at a preset speed, control the pressure of the wet clutch to start from zero and increase in preset steps, record the torque feedback value that shows a preset amplitude jump as the target torque value, and use the wet clutch pressure corresponding to the target torque value as the half-engagement point pressure value.

[0096] In some embodiments, the clutch torque clearing module 401 is used to control the engine output torque to drop to zero, obtaining an engine torque reduction value, which represents the amount of torque change required to reduce the engine output torque from the initial torque to zero torque; control the first motor to output a preset negative torque to suppress the residual torque of the engine and the first motor, where the residual torque represents the torque generated due to inertia or friction after the engine torque drops to zero; calculate a compensation torque based on the engine torque reduction value, and control the second motor to output the compensation torque to suppress negative impact and clear the torque of the wet clutch to zero; wherein, the negative impact includes the negative torque transmitted to the wheels during the torque suppression process, and the compensation torque is positively correlated with the amount of engine torque reduction.

[0097] In some embodiments, the torque capacity determination module 403 is used to determine whether the speed difference increases from zero and is greater than a preset slippage threshold; if the speed difference is greater than the slippage threshold, it is determined that the wet clutch has slipped and the output torque value of the first motor is recorded; the output torque value of the first motor is used as the torque capacity of the wet clutch under a preset pressure value.

[0098] In some embodiments, the wet clutch torque capacity determination device 400 further includes a graph generation module 404, which is used to traverse preset pressure values ​​to obtain multiple sets of calibration data, the calibration data including preset pressure values ​​and corresponding initial torque capacity; perform outlier removal processing on the multiple sets of calibration data; perform piecewise linear interpolation on the calibration data after removing outliers to generate calibration data to be verified, the calibration data to be verified including fitted torque; and perform accuracy verification on the calibration data to be verified to obtain a torque capacity graph, the torque capacity graph including the correspondence between the preset pressure values ​​and the torque capacity.

[0099] In some embodiments, the map generation module 404 is configured to calculate the absolute error between the torque capacity and the fitted torque, such that the absolute error is less than or equal to a first error threshold; and to calculate the relative error between the torque capacity and the fitted torque, such that the relative error is less than or equal to a second error threshold; and to verify the maximum relative error, such that the maximum relative error is less than or equal to a third error threshold; and to verify the average relative error, such that the average relative error is less than or equal to a fourth error threshold.

[0100] Specific limitations regarding the wet clutch torque capacity determination device can be found in the limitations of the voice recognition method described above, and will not be repeated here. Each module in the aforementioned wet clutch torque capacity determination device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the vehicle terminal in hardware form or independently of it, or stored in the memory of the vehicle terminal in software form, so that the processor can call and execute the corresponding operations of each module.

[0101] Based on the same inventive concept, embodiments of this application provide a vehicle-mounted terminal, which can be a server, and its internal structure diagram can be as follows. Figure 5 As shown, the vehicle-mounted terminal includes a processor, memory, and network interface connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage medium. The network interface is used to communicate with external terminals via a network connection. When the computer program is executed by the processor, it implements a method for determining the torque capacity of a wet clutch.

[0102] Those skilled in the art will understand that Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the vehicle terminal to which the present application is applied. A specific vehicle terminal may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0103] Based on the same inventive concept, this application provides an in-vehicle terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it performs the following steps: adjusting the input torque of the wet clutch to a zero torque state, continuously controlling the wet clutch pressure to a preset pressure value, increasing the output torque of the first motor based on a preset torque change rate, and controlling the second motor to compensate for torque; monitoring the speed difference between the first motor and the second motor in real time, and determining the torque capacity based on the speed difference. The torque capacity characterizes the maximum static friction torque that the wet clutch can transmit under the preset pressure value.

[0104] In some embodiments, when the processor executes a computer program, it further performs the following steps: The torque feedback value of the second motor is monitored in real time. When the torque feedback value of the second motor changes by a preset amplitude relative to the initial reference value, the thrust applied to the wet clutch is determined to be the target thrust.

[0105] In some embodiments, when the processor executes a computer program, it further performs the following steps: The first motor is locked, and the second motor is operated at a preset speed. The pressure of the wet clutch is controlled to increase from zero in preset steps. The torque feedback value that shows a preset amplitude jump is recorded as the target torque value, and the wet clutch pressure corresponding to the target torque value is used as the half-engagement point pressure value.

[0106] In some embodiments, when the processor executes a computer program, it further performs the following steps: The engine output torque is controlled to drop to zero, resulting in an engine torque reduction value. This value represents the amount of torque change required to reduce the engine output torque from its initial value to zero. A preset negative torque is then output by the first motor to suppress residual torque in both the engine and the first motor. This residual torque represents the torque generated due to inertia or friction after the engine torque drops to zero. A compensation torque is calculated based on the engine torque reduction value, and the second motor is then output to suppress negative impacts and clear the torque of the wet clutch to zero. The negative impact includes the negative torque transmitted to the wheels during torque suppression, and the compensation torque is positively correlated with the amount of engine torque reduction.

[0107] In some embodiments, when the processor executes a computer program, it further performs the following steps: Determine whether the speed difference increases from zero and exceeds the preset slippage threshold; if the speed difference exceeds the slippage threshold, determine that the wet clutch has slipped and record the output torque value of the first motor; use the output torque value of the first motor as the torque capacity of the wet clutch under the preset pressure value.

[0108] In some embodiments, when the processor executes a computer program, it further performs the following steps: The system iterates through preset pressure values ​​to obtain multiple sets of calibration data, which include preset pressure values ​​and corresponding initial torque capacities. Outlier removal is performed on the multiple sets of calibration data. Piecewise linear interpolation is then performed on the calibration data after outlier removal to generate calibration data to be verified, which includes fitted torque. Accuracy verification is then performed on the calibration data to be verified to obtain a torque capacity graph, which includes the correspondence between the preset pressure values ​​and torque capacities.

[0109] In some embodiments, when the processor executes a computer program, it further performs the following steps: Calculate the absolute error between the torque capacity and the fitted torque, such that the absolute error is less than or equal to a first error threshold; calculate the relative error between the torque capacity and the fitted torque, such that the relative error is less than or equal to a second error threshold; verify the maximum relative error, such that the maximum relative error is less than or equal to a third error threshold; and verify the average relative error, such that the average relative error is less than or equal to a fourth error threshold.

[0110] Based on the same inventive concept, embodiments of this application provide a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it performs the following steps: adjusting the input torque of the wet clutch to a zero torque state; continuously controlling the wet clutch pressure to a preset pressure value; increasing the output torque of the first motor based on a preset torque change rate; and controlling the second motor to compensate for torque; monitoring the speed difference between the first motor and the second motor in real time; determining the torque capacity based on the speed difference; and the torque capacity characterizing the maximum static friction torque that the wet clutch can transmit under the preset pressure value.

[0111] In some embodiments, when a computer program is executed by a processor, it further performs the following steps: The torque feedback value of the second motor is monitored in real time. When the torque feedback value of the second motor changes by a preset amplitude relative to the initial reference value, the thrust applied to the wet clutch is determined to be the target thrust.

[0112] In some embodiments, when a computer program is executed by a processor, it further performs the following steps: The first motor is locked, and the second motor is operated at a preset speed. The pressure of the wet clutch is controlled to increase from zero in preset steps. The torque feedback value that shows a preset amplitude jump is recorded as the target torque value, and the wet clutch pressure corresponding to the target torque value is used as the half-engagement point pressure value.

[0113] In some embodiments, when a computer program is executed by a processor, it further performs the following steps: The engine output torque is controlled to drop to zero, resulting in an engine torque reduction value. This value represents the amount of torque change required to reduce the engine output torque from its initial value to zero. A preset negative torque is then output by the first motor to suppress residual torque in both the engine and the first motor. This residual torque represents the torque generated due to inertia or friction after the engine torque drops to zero. A compensation torque is calculated based on the engine torque reduction value, and the second motor is then output to suppress negative impacts and clear the torque of the wet clutch to zero. The negative impact includes the negative torque transmitted to the wheels during torque suppression, and the compensation torque is positively correlated with the amount of engine torque reduction.

[0114] In some embodiments, when a computer program is executed by a processor, it further performs the following steps: Determine whether the speed difference increases from zero and exceeds the preset slippage threshold; if the speed difference exceeds the slippage threshold, determine that the wet clutch has slipped and record the output torque value of the first motor; use the output torque value of the first motor as the torque capacity of the wet clutch under the preset pressure value.

[0115] In some embodiments, when a computer program is executed by a processor, it further performs the following steps: The system iterates through preset pressure values ​​to obtain multiple sets of calibration data, which include preset pressure values ​​and corresponding initial torque capacities. Outlier removal is performed on the multiple sets of calibration data. Piecewise linear interpolation is then performed on the calibration data after outlier removal to generate calibration data to be verified, which includes fitted torque. Accuracy verification is then performed on the calibration data to be verified to obtain a torque capacity graph, which includes the correspondence between the preset pressure values ​​and torque capacities.

[0116] In some embodiments, when a computer program is executed by a processor, it further performs the following steps: Calculate the absolute error between the torque capacity and the fitted torque, such that the absolute error is less than or equal to a first error threshold; calculate the relative error between the torque capacity and the fitted torque, such that the relative error is less than or equal to a second error threshold; verify the maximum relative error, such that the maximum relative error is less than or equal to a third error threshold; and verify the average relative error, such that the average relative error is less than or equal to a fourth error threshold.

[0117] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0118] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0119] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for determining the torque capacity of a wet clutch, applied to a dual-motor hybrid transmission, the dual-motor hybrid transmission comprising a wet clutch, a first motor, and a second motor, wherein the first motor is connected to the input end of the wet clutch, and the second motor is connected to the output end of the wet clutch, characterized in that... The method includes: The input torque of the wet clutch is adjusted to zero torque, and the pressure of the wet clutch is continuously controlled to the preset pressure value. The output torque of the first motor is increased based on a preset torque change rate, and the second motor is controlled to compensate for the torque. The speed difference between the first motor and the second motor is monitored in real time, and the torque capacity is determined based on the speed difference. The torque capacity represents the maximum static friction torque that the wet clutch can transmit under the preset pressure value.

2. The method according to claim 1, characterized in that, The preset pressure value is greater than the half-engagement point pressure value, which includes the minimum pressure value required to move the wet clutch piston to the contact friction plate by applying the target thrust. Determining the target thrust includes: The torque feedback value of the second motor is monitored in real time. When the torque feedback value of the second motor changes by a preset amplitude relative to the initial reference value, the thrust applied to the wet clutch is determined to be the target thrust.

3. The method according to claim 2, characterized in that, The method for determining the pressure value at the semi-junction point is as follows: The first motor is locked, and the second motor is controlled to operate at a preset speed. The pressure of the wet clutch is controlled to increase from zero in preset steps; The torque feedback value that exhibits a preset amplitude jump is recorded as the target torque value, and the wet clutch pressure corresponding to the target torque value is used as the half-engagement point pressure value.

4. The method according to claim 1, characterized in that, Adjusting the input torque at the front end of the wet clutch to a zero torque state includes: The engine output torque is controlled to drop to zero, and the engine torque drop value is obtained. The engine torque drop value represents the amount of torque change when the engine output torque is reduced from the initial torque to zero torque. The first motor is controlled to output a preset negative torque to suppress the residual torque of the engine and the first motor. The residual torque represents the torque generated due to inertia or friction after the engine torque drops to zero. The compensation torque is calculated based on the decrease in engine torque, and the second motor is controlled to output the compensation torque; the compensation torque is positively correlated with the decrease in engine torque.

5. The method according to any one of claims 1-4, characterized in that, Determining the torque capacity based on the speed difference includes: Determine whether the speed difference increases from zero and exceeds a preset slippage threshold; If the speed difference is greater than the slippage threshold, it is determined that the wet clutch has slipped, and the output torque value of the first motor is recorded. The output torque value of the first motor is used as the torque capacity of the wet clutch under a preset pressure value.

6. The method according to any one of claims 1-4, characterized in that, The method further includes: By iterating through preset pressure values, multiple sets of calibration data are obtained, including preset pressure values ​​and corresponding initial torque capacity. Outlier removal is performed on the multiple sets of calibration data; piecewise linear interpolation is performed on the calibration data after outlier removal to generate calibration data to be verified, the calibration data to be verified including the fitted torque; The accuracy of the calibration data to be verified is checked to obtain the torque capacity map, which includes the correspondence between the preset pressure value and the torque capacity.

7. The method according to claim 6, characterized in that, The accuracy verification of the calibration data to be verified includes: Calculate the absolute error between the torque capacity and the fitted torque, such that the absolute error is less than or equal to a first error threshold. And, calculate the relative error between the torque capacity and the fitted torque, such that the relative error is less than or equal to a second error threshold; In addition, the maximum relative error is verified such that the maximum relative error is less than or equal to a third error threshold; In addition, the average relative error is verified such that the average relative error is less than or equal to the fourth error threshold.

8. A device for determining the torque capacity of a wet clutch, characterized in that, include: The clutch torque clearing module is used to adjust the input torque of the wet clutch to a zero torque state and continuously control the pressure of the wet clutch to the preset pressure value. The motor control module is used to increase the output torque of the first motor based on a preset torque change rate, and to control the second motor to compensate for torque. The torque capacity determination module is used to monitor the speed difference between the first motor and the second motor in real time, and determine the torque capacity based on the speed difference. The torque capacity represents the maximum static friction torque that the wet clutch can transmit under a preset pressure value.

9. A vehicle-mounted terminal, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the wet clutch torque capacity determination method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a plurality of instructions adapted for loading by a processor and implementing the wet clutch torque capacity determination method as described in any one of claims 1 to 7.

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