Engine torque precision inspection method
By calculating and modifying the engine torque, the problem of torque accuracy is difficult to measure under the complex operating conditions of the vehicle, and the efficient shifting control and the life of the clutch are extended.
Patent Information
- Application Number
- CN202411655842.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-19
- Publication Date
- 2025-01-28
AI Technical Summary
The prior art cannot effectively measure engine torque accuracy under complex operating conditions of vehicles, and additional costs are required to measure sensors, which affects economics.
By obtaining the characteristic curve of the torque transformer speed ratio and the torque converter, calculate the input torque at the input speed of different pump wheels, and calculate the correction coefficient based on the net torque and input torque of the ECU broadcast. Essence
Without increasing the cost of hardware, the inspection and correction of the engine torque accuracy is achieved, the shift quality of the fluid automatic transmission is improved, and the service life of the clutch is extended.
Smart Images
Figure CN119373865A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of automobile engines, and in particular, to a method for checking engine torque accuracy. Background Art
[0002] For vehicles equipped with hydraulic automatic transmission, during operation, the engine controller (Electronic Control Unit, ECU) and the hydraulic automatic transmission controller (Transmission Control Unit, TCU) exchange signals through the CAN bus. During normal vehicle operation, the TCU switches the target gear according to the throttle signal and speed signal according to the shift table built into the TCU, and controls the clutch pressure curve according to the torque signal broadcast by the ECU and interacts with the ECU for torque response. Figure 1 The diagram shows the vehicle components. During vehicle operation, the ECU and TCU exchange signals through the CAN bus. The TCU receives the CAN bus message from the engine and controls the gear shifting of the transmission according to the real-time operating status of the engine to realize the driver's driving intention. Figure 2 The schematic diagram shows the signal interaction between ECU and TCU through CAN bus. TCU receives the message information from ECU. Through signal interaction, TCU can optimize the transmission according to the status of the vehicle and engine to improve the performance of the vehicle.
[0003] When the hydraulic automatic transmission switches gears, the TCU adjusts the clutch control curve according to the received engine torque signal to ensure the smoothness of the gear shift. Therefore, the engine torque accuracy broadcast by the ECU is crucial to clutch control and has a great impact on the shift quality of the hydraulic automatic transmission. When the TCU issues a shift command, the engine speed at the start of the shift is determined, and the engine speed at the completion of the shift is also determined. At the same time, the engine rotational inertia is also determined, so it is concluded that the inertia amount in the clutch inertia phase control process is fixed. Therefore, when the engine torque accuracy deviation is large, it will cause the speed of the inertia phase to change too fast or too slow, affecting the smoothness of the gear shift.
[0004] Figure 3The schematic diagram of the clutch control curve is shown, (1) when the actual engine torque is lower than the broadcast torque, the clutch control curve is shown as the red curve, (2) when the actual engine torque is higher than the broadcast torque, the clutch control curve is shown as the blue curve. When the actual engine torque is lower than the broadcast torque, the clutch torque will be higher than the actual engine torque, so the input shaft speed changes too quickly, affecting the driving experience; when the actual engine torque is higher than the broadcast torque, the clutch torque will be lower than the actual engine torque, causing the input shaft speed to change too slowly, the slip time is long, and the life of the clutch friction plate is affected. Therefore, it is necessary to ensure the engine torque accuracy to ensure that the clutch control curve is as shown Figure 3 As shown by the green curve in the middle, an engine torque accuracy inspection method is needed to verify the engine torque accuracy and make torque corrections according to the torque accuracy when the TCU performs clutch control, thereby improving the shift quality of the hydraulic automatic transmission and extending the life of the clutch. However, in the prior art, due to the complex operating conditions of the vehicle, it is impossible to measure the engine torque accuracy under all operating conditions; if an external sensor is used to measure the torque accuracy, additional costs will be incurred. Summary of the invention
[0005] In order to overcome at least one deficiency in the prior art, the present application provides an engine torque accuracy inspection method.
[0006] In a first aspect, a method for checking engine torque accuracy is provided, comprising:
[0007] Obtaining the speed ratio of the torque converter, and determining the input torque at a specific pump wheel speed under the speed ratio of the torque converter according to the characteristic curve of the hydraulic torque converter;
[0008] Calculate the input torque at different pump impeller input speeds based on the pump impeller input speed and the input torque at a specific pump impeller speed under the torque converter speed ratio;
[0009] Obtain the net torque broadcast by the ECU at different pump input speeds, and calculate the correction coefficient at different pump input speeds based on the net torque and the input torque at different pump input speeds;
[0010] The net torque broadcast by the ECU at different impeller input speeds is corrected according to the correction factor.
[0011] In one embodiment, the input torque at different pump input speeds is calculated based on the pump input speed and the input torque at a specific pump speed under the torque converter speed ratio, using the following formula:
[0012]
[0013] Among them, T1 k is the input torque at the kth pump input speed, PS kis the kth pump input speed, T2 i is the specific pump impeller speed PS at the torque converter speed ratio i 特定 The input torque is
[0014] In one embodiment, the correction coefficient at different impeller input speeds is calculated based on the net torque and the input torque at different impeller input speeds, including:
[0015]
[0016] Among them, coef k is the correction coefficient at the kth pump input speed, T1 k is the input torque at the kth pump input speed, T3 k is the net torque broadcast by the ECU at the kth impeller input speed.
[0017] In one embodiment, the torque converter ratio is 0.
[0018] In one embodiment, the specified impeller speed is 1700 rpm.
[0019] In one embodiment, different impeller input rotation speeds are 600 rpm, 900 rpm, 1200 rpm, 1500 rpm, and 1800 rpm.
[0020] In a second aspect, an engine torque accuracy inspection device is provided, comprising:
[0021] A torque determination module, used for obtaining a torque converter speed ratio and determining an input torque at a specific pump wheel speed under the torque converter speed ratio according to a characteristic curve of the hydraulic torque converter;
[0022] a torque calculation module, for calculating input torques at different pump input speeds based on the pump input speed and the input torque at a specific pump speed under a torque converter speed ratio;
[0023] A correction coefficient calculation module is used to obtain the net torque broadcast by the ECU at different pump input speeds, and calculate the correction coefficient at different pump input speeds according to the net torque and the input torque at different pump input speeds;
[0024] The correction module is used to correct the net torque broadcast by the ECU at different pump input speeds according to a correction coefficient.
[0025] On the third aspect, an engine torque accuracy inspection system is provided, including a TCU, a CAN bus and an ECU, the ECU is used to send the net torque broadcast by the ECU at different pump input speeds to the TCU through the CAN bus, and the TCU is used to implement the above-mentioned engine torque accuracy inspection method.
[0026] Compared with the prior art, the present application has the following beneficial effects: the engine torque accuracy inspection method of the present application can inspect the engine torque accuracy and calculate the engine torque correction coefficient without increasing the hardware cost, and correct the net torque broadcast by the ECU when the TCU performs gear shift control, thereby avoiding torque imbalance during the gear shifting process that causes gear shifting shock, clutch wear, etc., which can effectively improve the gear shifting quality and extend the service life of the clutch. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The present application may be better understood by referring to the following description given in conjunction with the accompanying drawings, which together with the following detailed description are included in this specification and form a part of this specification. In the drawings:
[0028] Figure 1 A simplified diagram of the vehicle composition is shown;
[0029] Figure 2 A schematic diagram showing signal interaction between ECU and TCU via CAN bus;
[0030] Figure 3 A schematic diagram of a clutch control curve is shown;
[0031] Figure 4 A flowchart of an engine torque accuracy checking method is shown;
[0032] Figure 5 The structural block diagram of the engine torque accuracy inspection device is shown. DETAILED DESCRIPTION
[0033] The exemplary embodiments of the present application will be described below in conjunction with the accompanying drawings. For the sake of clarity and conciseness, not all features of the actual embodiments are described in the specification. However, it should be understood that many implementation-specific decisions can be made in the process of developing any such actual embodiments in order to achieve the specific goals of the developer, and these decisions may vary from embodiment to embodiment.
[0034] It is also necessary to explain here that, in order to avoid obscuring the present application due to unnecessary details, only the device structure closely related to the scheme according to the present application is shown in the drawings, while other details that are not closely related to the present application are omitted.
[0035] It should be understood that the present application is not limited to the described implementation forms due to the following description with reference to the accompanying drawings. In this article, where feasible, the embodiments can be combined with each other, features between different embodiments can be replaced or borrowed, and one or more features can be omitted in one embodiment.
[0036] The present application provides a method for checking engine torque accuracy. Figure 4 A flowchart of the engine torque accuracy inspection method is shown in FIG. Figure 4 , methods include:
[0037] Step S1, obtaining the speed ratio of the transmission torque, and determining the input torque at a specific pump wheel speed under the torque converter speed ratio according to the characteristic curve of the torque converter.
[0038] Here, the characteristic curve related data of the torque converter are shown in Table 1. The characteristic curve related data of the torque converter include the specific pump wheel speed PS 特定 Input torque, efficiency, speed ratio and torque ratio at . In Table 1, the specific impeller speed is 1700 rpm.
[0039] Table 1
[0040]
[0041] Among them, the torque converter speed ratio i = turbine speed ÷ pump wheel speed.
[0042] Efficiency = (turbine speed * turbine torque) ÷ (pump speed * pump torque)
[0043] Torque ratio = turbine torque ÷ pump torque
[0044] According to Table 1, the input torque at a specific pump wheel speed under a specific torque converter speed ratio can be obtained.
[0045] Step S2, calculating the input torque at different pump impeller input speeds based on the pump impeller input speed and the input torque at a specific pump impeller speed under the torque converter speed ratio.
[0046] Specifically, the input torque at different pump input speeds can be calculated using the following formula:
[0047]
[0048] Among them, T1 k is the input torque at the kth pump input speed, PS k is the kth pump input speed, T2 i is the specific pump impeller speed PS at the torque converter speed ratio i 特定 Input torque at .
[0049] Step S3, obtaining the net torque broadcast by the ECU at different pump input speeds, and calculating the correction coefficient at different pump input speeds according to the net torque and the input torque at different pump input speeds.
[0050] Specifically, the correction factor is calculated using the following formula:
[0051]
[0052] Among them, coef k is the correction coefficient at the kth pump input speed, T1 k is the input torque at the kth pump input speed, T3 k is the net torque broadcast by the ECU at the kth impeller input speed.
[0053] Step S4, correcting the net torque broadcast by the ECU at different pump input speeds according to the correction coefficient.
[0054] Here, the correction coefficient is multiplied by the net torque broadcast by the ECU at the corresponding pump input speed to obtain the corrected net torque, which is applied to the inertia phase control process as shown in the following formula:
[0055]
[0056] Among them, ω e1 is the engine speed at the time when the gear shift is completed, ω e0 is the engine speed at the start of the shift, I e is the engine moment of inertia, T e is the transmission input torque, i.e. the net torque broadcast by the ECU, T c is the torque transmitted by the clutch, time1 is the end time of the gear shift, time0 is the start time of the gear shift, and coef is the correction coefficient.
[0057] The engine torque accuracy inspection method of the above-mentioned embodiment can inspect the engine torque accuracy and calculate the engine torque correction coefficient without increasing the hardware cost, and correct the net torque broadcast by the ECU when the TCU performs shift control, thereby avoiding torque imbalance during the shifting process that causes shifting shock, clutch wear, etc., which can effectively improve the shifting quality and delay the service life of the clutch.
[0058] In one embodiment, bus message information of the engine is obtained through the CAN bus, as shown in Table 2.
[0059] Table 2
[0060]
[0061] After starting the vehicle engine, shift the gearbox into D gear, and step on the brake to stop the vehicle. At this time, the engine speed is maintained in the specified speed range EOS1, EOS2, EOS3, EOS4, and EOS5 by controlling the accelerator pedal, and the engine torque information broadcast by the ECU is recorded at this time, as shown in Table 3. In this embodiment, EOS1~EOS6 (different pump wheel input speeds) are 600rpm (revolutions / minute), 900rpm, 1200rpm, 1500rpm, and 1800rpm respectively.
[0062] Table 3
[0063]
[0064]
[0065] T3 k =SPN544*(SPN512-SPN514-SPN2978)
[0066] The vehicle is put into D gear and the brake is pressed to stop the vehicle, which is equivalent to the torque converter speed ratio i being 0 at this time. According to step S2, when the torque converter speed ratio is 0, the pump input speed is calculated to be the input torque under EOS1, EOS2, EOS3, EOS4, and EOS5, respectively. As shown in Table 4.
[0067] Table 4
[0068] Speed (rpm) Torque value T1 calculated based on the torque converter characteristic curve EOS1 <![CDATA[T11]]> EOS2 <![CDATA[T12]]> EOS3 <![CDATA[T13]]> EOS4 <![CDATA[T14]]> EOS5 <![CDATA[T15]]>
[0069] According to step S3, the correction coefficients at different pump impeller input speeds are calculated, as shown in Table 5.
[0071] Table 5
[0072] Speed (rpm) Torque correction factor coef EOS1 <![CDATA[coef1]]> EOS2 <![CDATA[coef2 <!-- 5 -->]]> EOS3 <![CDATA[coef3]]> EOS4 <![CDATA[coef4]]> EOS5 <![CDATA[coef5]]>
[0073] Then, a lookup table is designed according to the calculated correction coefficients at different pump input speeds, the correction coefficients are obtained by looking up the table according to the pump input speed during the gear shifting process, and the correction coefficients are applied to the inertia phase control process.
[0074] Based on the same inventive concept as the engine torque accuracy inspection method, this embodiment also provides a corresponding engine torque accuracy inspection device. Figure 5 The structure block diagram of the engine torque accuracy inspection device is shown, comprising:
[0075] The torque determination module 51 is used to obtain the torque converter speed ratio and determine the input torque at a specific pump wheel speed under the torque converter speed ratio according to the characteristic curve of the hydraulic torque converter;
[0076] The torque calculation module 52 is used to calculate the input torque at different pump input speeds according to the pump input speed and the input torque at a specific pump speed under the torque converter speed ratio;
[0077] A correction coefficient calculation module 53 is used to obtain the net torque broadcast by the ECU at different pump input speeds, and calculate the correction coefficient at different pump input speeds according to the net torque and the input torque at different pump input speeds;
[0078] The correction module 54 is used to correct the net torque broadcast by the ECU at different pump input speeds according to the correction coefficient.
[0079] The engine torque accuracy inspection device of this embodiment has the same inventive concept as the engine torque accuracy inspection method described above, so the specific implementation method of the device can be seen in the implementation example part of the engine torque accuracy inspection method in the previous text, and its technical effect corresponds to the technical effect of the above method, which will not be repeated here.
[0080] An embodiment of the present application also provides an engine torque accuracy inspection system, including a TCU, a CAN bus and an ECU, wherein the ECU is used to send the net torque broadcast by the ECU at different pump input speeds to the TCU through the CAN bus, and the TCU is used to implement the above-mentioned engine torque accuracy inspection method.
[0081] The specific implementation of the system can be seen in the embodiment section of the engine torque accuracy inspection method in the previous text, and its technical effect corresponds to the technical effect of the above method, which will not be repeated here.
[0082] The above are only various implementations of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.
Claims
1. A method for checking engine torque accuracy, characterized in that: include: Obtaining a torque converter speed ratio, and determining an input torque at a specific pump impeller speed under the torque converter speed ratio according to a characteristic curve of the hydraulic torque converter; Calculating the input torque at different pump impeller input speeds according to the pump impeller input speed and the input torque at a specific pump impeller speed under the torque converter speed ratio; Obtaining a net torque broadcast by the ECU at different pump input speeds, and calculating a correction coefficient at different pump input speeds according to the net torque and the input torque at different pump input speeds; The net torque broadcast by the ECU at the different pump input speeds is corrected according to the correction coefficient.
2. The method according to claim 1, characterized in that in, Based on the impeller input speed and the input torque at a specific impeller speed under the torque converter speed ratio, the input torque at different impeller input speeds is calculated using the following formula: Among them, T1 k is the input torque at the kth pump input speed, PS k is the kth pump input speed, T2 i is the specific pump impeller speed PS at the torque converter speed ratio i 特定 Input torque at .
3. The method according to claim 1, characterized in that in, Calculating correction coefficients at different pump input speeds according to the net torque and the input torque at different pump input speeds includes: Among them, coef k is the correction coefficient at the kth pump input speed, T1 k is the input torque at the kth pump input speed, T3 k is the net torque broadcast by the ECU at the kth impeller input speed.
4. The method according to claim 1, characterized in that The torque converter speed ratio is 0.
5. The method according to claim 1, characterized in that The specific pump impeller speed is 1700 rpm.
6. The method according to claim 1, characterized in that The different pump wheel input rotation speeds are 600 rpm, 900 rpm, 1200 rpm, 1500 rpm and 1800 rpm.
7. An engine torque accuracy inspection device, characterized in that: include: A torque determination module, used for obtaining a torque converter speed ratio and determining an input torque at a specific pump wheel speed under the torque converter speed ratio according to a characteristic curve of the hydraulic torque converter; a torque calculation module, for calculating the input torque at different pump impeller input speeds according to the pump impeller input speed and the input torque at a specific pump impeller speed under the torque converter speed ratio; A correction coefficient calculation module, used for obtaining the net torque broadcast by the ECU at different pump input speeds, and calculating the correction coefficient at different pump input speeds according to the net torque and the input torque at different pump input speeds; The correction module is used to correct the net torque broadcast by the ECU at the different pump input speeds according to the correction coefficient.
8. An engine torque accuracy inspection system, characterized in that: It includes a TCU, a CAN bus and an ECU, wherein the ECU is used to send the net torque broadcast by the ECU at different pump input speeds to the TCU through the CAN bus, and the TCU is used to implement the engine torque accuracy inspection method described in any one of claims 1-6.