A method and system for evaluating torque converter lockup shock

Abstract

The application discloses a kind of evaluation method and system of variator lockup shock, the method includes: monitoring variator turbine speed and transmission output speed;Combination the variator turbine speed and the transmission output speed determines first evaluation index, and according to the transmission output speed determines second evaluation index;Combination the first evaluation index and the second evaluation index, or separately using the second evaluation index evaluates the variator lockup shock torque.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a method and system for evaluating torque converter lock-up impact. Background Technology

[0002] With the continuous development of hydraulic automatic transmission technology, high-power hydraulic automatic transmissions are gradually being applied to medium and heavy-duty trucks, special-purpose vehicles, special off-road vehicles, and construction machinery. In order to ensure the smooth operation of vehicles, an easy-to-promote and objective evaluation method and evaluation index are needed for torque converter lock-up, one of the core functions of hydraulic automatic transmissions.

[0003] In evaluating hydraulic automatic transmissions, existing methods typically involve adding testing equipment such as acceleration sensors, GPS sensors, and laser cameras. However, these additional testing devices are not designed into hydraulic automatic transmissions and the vehicles they are installed in, and since vehicle models vary, it is impossible to analyze the lock-up impact of each hydraulic automatic transmission, thus lacking widespread applicability. Summary of the Invention

[0004] To address the technical problem of low promotional value caused by the need for additional testing equipment in existing technologies, this invention provides a method and system for evaluating torque converter lock-up impact. Without relying on additional testing equipment, this method objectively evaluates the magnitude of torque converter lock-up impact and its impact on vehicle ride comfort based on the measurable operating parameters of the high-power hydraulic automatic transmission itself. The technical solution of this invention can serve as the basis for evaluating the effectiveness of torque converter lock-up control and optimizing calibration parameters, and thus has promotional value.

[0005] To address the aforementioned technical problems, a first aspect of the present invention discloses a method for evaluating torque converter lock-up impact, the method comprising:

[0006] Monitor torque converter turbine speed and transmission output speed;

[0007] A first evaluation index is determined by combining the torque converter turbine speed and the transmission output speed, and a second evaluation index is determined based on the transmission output speed.

[0008] The torque converter lock-up impact torque is evaluated by combining the first evaluation index and the second evaluation index, or by using the second evaluation index alone.

[0009] Preferably, the monitoring of the torque converter turbine speed and the transmission output speed specifically includes:

[0010] Using a hydraulic automatic transmission to monitor the transmission output speed at each moment during the torque converter lock-up process Torque converter turbine speeds at various moments during the torque converter lock-up process Where i represents the current gear and j represents the moment during the transmission lock-up process.

[0011] Preferably, according to the formula Obtain the speed ratio Δi of the planetary transmission mechanism at each time point. g ; where i gC This represents the theoretical gear ratio corresponding to the current gear of the hydraulic automatic transmission when the torque converter is locked; it is a fixed value.

[0012] Based on the speed ratio Δi of the planetary transmission mechanism at each moment g By subtracting the values ​​from each other and taking the absolute value, the maximum difference in speed ratio Δi of the planetary transmission mechanism can be determined. gmax This serves as the first evaluation indicator.

[0013] Preferably, determining the second evaluation index based on the output speed of the transmission specifically includes:

[0014] Based on the transmission output speed at each time point By subtracting the values ​​from each other and taking the absolute value, the maximum difference Δn between the transmission output speeds can be determined. pc.max This serves as the second evaluation indicator.

[0015] Preferably, the step of evaluating the torque converter lock-up impact torque by combining the first evaluation index and the second evaluation index, or by using the second evaluation index alone, specifically includes:

[0016] Determine the maximum speed ratio difference Δi of the planetary transmission mechanism. gmax Is it greater than the design threshold C?

[0017] If Δi gmax If the value is greater than C, then the maximum speed ratio difference Δi of the planetary transmission mechanism is used. gmax Maximum difference in transmission output speed Δn pc.max The torque converter lock-up impact torque is jointly evaluated; wherein, if the maximum speed ratio difference Δi of the planetary transmission mechanism during the torque converter lock-up process is... gmax If the values ​​are different, then the maximum difference in the speed ratio of the planetary transmission mechanism is Δi. gmax The larger the value, the greater the torque converter lock-up impact torque; if the maximum speed ratio difference Δi of the planetary transmission mechanism during the torque converter lock-up process... gmax If the values ​​are the same, then the maximum difference in the output speed of the transmission is Δn. pc.max The larger the value, the greater the lock-up impact torque of the torque converter;

[0018] If Δi gmax If ≤C, then the maximum difference in output speed Δn of the transmission is used alone.pc.max The torque converter lock-up impact torque is evaluated; wherein, the maximum difference in output speed of the transmission is Δn. pc.max The larger the value, the greater the lock-up impact torque of the torque converter.

[0019] Preferably, the second evaluation index is also used to evaluate the sole evaluation index of the impact of the torque converter lock-up shock on vehicle ride comfort.

[0020] A second aspect of the present invention discloses an evaluation system for torque converter lock-up impact, the system comprising:

[0021] The monitoring module is used to monitor the torque converter turbine speed and the transmission output speed;

[0022] The first determining module is used to determine a first evaluation index by combining the torque converter turbine speed and the transmission output speed, and to determine a second evaluation index based on the transmission output speed.

[0023] The evaluation module is used to evaluate the torque converter lock-up impact torque by combining the first evaluation index and the second evaluation index, or by using the second evaluation index alone.

[0024] Through one or more technical solutions of the present invention, the present invention has the following beneficial effects or advantages:

[0025] The technical solution of this invention objectively evaluates the magnitude of torque converter lock-up impact and its impact on vehicle ride comfort based on the measurable operating parameters of a high-power hydraulic automatic transmission, without relying on additional testing equipment. Furthermore, by comparing the torque converter lock-up impact torque with the torque capacity, different operating parameters are used to obtain evaluation indicators, making the evaluation more targeted and allowing for different corresponding measures to be taken in different situations. The technical solution of this invention can serve as the basis for evaluating the effectiveness of torque converter lock-up control and optimizing calibration parameters, and has widespread application value.

[0026] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0027] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0028] In the attached diagram:

[0029] Figure 1 A flowchart of a method for evaluating torque converter lock-up impact according to an embodiment of the present invention is shown;

[0030] Figure 2 A schematic diagram of the lock-up process of the 3rd gear torque converter of a high-power hydraulic automatic transmission according to an embodiment of the present invention is shown.

[0031] Figure 3 A schematic diagram of the speed change curve when the torque converter is locked according to an embodiment of the present invention is shown;

[0032] Figure 4 A schematic diagram of an evaluation system for torque blockage impact according to an embodiment of the present invention is shown. Detailed Implementation

[0033] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0034] To gain a detailed understanding of the implementation scenarios of this invention, the following section will first describe the torque converter's unlocking function and operating characteristics, as well as the causes of torque converter lock-up impact.

[0035] (1) Torque converter unlocking and locking functions and working characteristics.

[0036] In heavy-duty vehicle hydraulic automatic transmissions, lockable torque converters are widely used to improve transmission efficiency, power utilization, and dynamic performance. The lock-up control of the torque converter includes two scenarios:

[0037] a. To improve transmission efficiency, the torque converter is locked; to increase drive torque, the torque converter is unlocked. When the torque converter enters coupling mode or a certain torque converter turbine speed range, the turbine and pump wheel are locked together by a clutch, changing from hydraulic transmission to direct mechanical transmission. Conversely, when operating in mechanical transmission mode and the engine is under strain while the torque converter turbine speed drops to a certain range, the lock should be disengaged to restore hydraulic transmission mode, so as to fully utilize the torque converter's torque-enhancing effect and improve the vehicle's traction performance.

[0038] b. To improve shift quality, the torque converter is unlocked for buffering. Before each shift in the hydraulic automatic transmission, in order to utilize the buffering effect of the hydraulic components, the oil supply to the lock-up clutch is interrupted for a short period of time, the torque converter is unlocked, and hydraulic transmission is switched to improve shift quality. After the shift is completed, in order to improve transmission efficiency and vehicle speed, the oil supply to the lock-up clutch is restored, and the torque converter is locked again.

[0039] (2) Causes of torque converter lock-up impact.

[0040] On a smooth, level road surface, as the vehicle accelerates and shifts gears to overcome driving resistance under the engine's action, before the torque converter locks in, there is a significant speed difference between the turbine assembly and the pump wheel assembly. For heavy vehicles, the equivalent moment of inertia of the assembly connected to the turbine is much greater than that of the assembly connected to the pump wheel. Furthermore, since the torque converter lock-in time is generally extremely short, the turbine assembly's speed will remain essentially constant during the torque converter lock-in period, while the pump wheel assembly's speed will drop sharply. This sudden drop in pump wheel assembly speed will release a large amount of inertial energy, which will be converted into a huge impact torque disturbance and transmitted to the vehicle. This will cause torque and speed fluctuations in the vehicle's powertrain system, affecting the passenger's ride comfort.

[0041] Therefore, to ensure smooth vehicle operation, it is necessary to evaluate torque converter lock-up impact. This invention discloses a method for evaluating torque converter lock-up impact, applicable to medium and heavy-duty trucks, special-purpose vehicles, special off-road vehicles, and construction machinery. See also... Figure 1 The method includes the following steps:

[0042] Step 101: Monitor the torque converter turbine speed and the transmission output speed.

[0043] Step 102: Determine the first evaluation index by combining the torque converter turbine speed and the transmission output speed, and determine the second evaluation index based on the transmission output speed.

[0044] Step 103: Combine the first evaluation index and the second evaluation index, or use the second evaluation index alone to evaluate the torque converter lock-up impact torque.

[0045] The technical solution of this invention objectively evaluates the magnitude of torque converter lock-up impact and its impact on vehicle ride comfort based on the measurable operating parameters of a high-power hydraulic automatic transmission, without relying on additional testing equipment. Furthermore, by comparing the magnitude of the torque converter lock-up impact torque and torque capacity, different operating parameters are used to obtain evaluation indicators, making the evaluation more targeted and allowing for different corresponding measures to be taken in different situations. The technical solution of this invention can serve as the basis for evaluating the effectiveness of torque converter lock-up control and optimizing calibration parameters, and has widespread application value.

[0046] Specifically, the torque converter includes an unlocking process and a locking process. During the locking process, the locking impact torque disturbance generated by the torque converter is transmitted to the vehicle, causing fluctuations in torque and speed in the vehicle's powertrain. The locking impact torque generated by the torque converter during the locking process is correlated with the torque capacity of the clutch engaged in the current gear. Therefore, this embodiment evaluates the torque converter locking impact by considering the torque converter locking impact torque and the torque capacity of the clutch engaged in the current gear.

[0047] With attachment Figure 2 The following example illustrates the lock-up process of the 3rd gear torque converter in a certain type of high-power hydraulic automatic transmission. Figure 2 In the case of a high-power hydraulic automatic transmission, there are torque converter lock-up clutches C0 and various shift clutches: C1, C2, B1, B2, and B3.

[0048] When the torque converter lock-up impact torque is less than the torque capacity of the clutch engaged in the current gear, the hydraulic automatic transmission will rigidly transmit the torque, thus the impact torque will directly cause a change in the transmission's output speed. When the torque converter lock-up impact torque is greater than the torque capacity of the clutch engaged in the current gear, the impact torque will cause the shift clutch (see appendix) to... Figure 2 If the friction pairs (C1, C2, B1, B2, B3) slip, the speed ratio of the planetary transmission mechanism will deviate from the current gear ratio and change significantly in a short period of time. Therefore, the extremely large impact torque will not only cause changes in the output speed of the transmission, but also cause violent fluctuations in the speed ratio of the planetary transmission mechanism.

[0049] In Figure 2 During the torque converter lock-up process, the trends of torque converter pump wheel speed, torque converter turbine speed, and transmission output speed are shown in the attached figure. Figure 3 As shown in the figure, t1 and t2 represent the start and end times of torque converter lock-up. Before torque converter lock-up begins, there is a significant speed difference between the torque converter pump wheel speed and the torque converter turbine speed. The speed ratio between the torque converter turbine speed and the transmission output speed is the theoretical speed ratio of the current gear. After the torque converter lock-up process begins, the speed difference between the torque converter pump wheel speed and the torque converter turbine speed gradually decreases. The lock-up impact torque will act on the vehicle's powertrain system, causing the torque converter turbine speed and the transmission output speed to oscillate, and its speed ratio to oscillate around the theoretical speed ratio. When the torque converter pump wheel speed and the torque converter turbine speed are equal and stable, and the speed ratio between the torque converter turbine speed and the transmission output speed returns to the theoretical speed ratio and stabilizes, the torque converter lock-up process ends.

[0050] Therefore, to evaluate the torque converter lock-up impact torque, this embodiment uses its own measurable operating parameters—torque converter turbine speed and transmission output speed—as the basis for constructing evaluation indicators. The evaluation indicators and their interpretations are as follows:

[0051] Maximum difference in transmission output speed Δn pc.max.

[0052] Both excessively large and insufficient torque converter lock-up impact torque can affect the transmission's output speed. For example, if the torque converter lock-up impact torque is less than the torque capacity of the clutch engaged in the current gear, the entire impact torque will act on the vehicle's powertrain, causing a sudden change in the transmission's output speed. Conversely, if the torque converter lock-up impact torque is too large, or even greater than the torque capacity of the clutch engaged in the current gear, the clutch friction pair will experience low-speed slippage and heat generation, consuming some of the lock-up impact energy. The remaining portion will still act on the vehicle's powertrain, causing a sudden change in the transmission's output speed.

[0053] Therefore, during the transmission lock-up process, the maximum difference in transmission output speed Δn can be... pc.max As an important indicator for evaluating the magnitude of transmission lock-up impact torque, the maximum difference in transmission output speed Δn pc.max The larger the value, the greater the torque converter lock-up impact torque.

[0054] Maximum speed ratio difference Δi of planetary transmission mechanism gmax .

[0055] If the torque converter lock-up impact torque is too large, for example, if the torque converter lock-up impact torque exceeds the torque capacity, taking the 3rd gear torque converter lock-up as an example, when the lock-up impact torque exceeds the torque capacity of clutches C1 and B1, the friction pair of clutch C1, which has a relatively smaller torque capacity, will experience low-speed slippage. This manifests as the actual speed ratio of the planetary transmission mechanism deviating from the theoretical speed ratio. Taking 3rd gear as an example, the actual speed ratio of the planetary transmission structure will be lower than the theoretical speed ratio of the planetary transmission structure. i gC The oscillation causes the planetary transmission ratio to be the maximum difference Δi between the maximum and minimum actual speed ratios during torque converter lock-up. gmax It is also used as an important indicator for evaluating the torque converter lock-up impact torque, and is used to evaluate the transmission lock-up impact torque. The maximum speed ratio difference Δi of the planetary transmission mechanism. gmax The larger the value, the greater the torque converter lock-up impact torque. Furthermore, the maximum speed ratio difference Δi in the planetary transmission mechanism... gmax It is not related to the gear position.

[0056] To further illustrate and explain the present invention, the first evaluation index (maximum speed ratio difference Δi of the planetary transmission mechanism) will be discussed below. gmax ) and the second evaluation index (maximum difference in transmission output speed Δn) pc.max (This will be explained.)

[0057] First evaluation index (maximum speed ratio difference Δi of planetary transmission mechanism) gmax )

[0058] In this embodiment, in order to obtain the maximum speed ratio difference Δi of the planetary transmission mechanism gmax Perform as follows:

[0059] First, the transmission output speed at each moment during the torque converter lock-up process is monitored using a hydraulic automatic transmission. Torque converter turbine speeds at various moments during the torque converter lock-up process Where i represents the current gear and j represents the moment during the transmission lock-up process.

[0060] Secondly, according to the formula Obtain the speed ratio Δi of the planetary transmission mechanism at each time point. g ; where i gC This represents the theoretical gear ratio corresponding to the current gear of the hydraulic automatic transmission when the torque converter is locked; it is a fixed value.

[0061] Finally, based on the speed ratio Δi of the planetary transmission mechanism at each moment... g By subtracting the values ​​from each other and taking the absolute value, the maximum difference in speed ratio Δi of the planetary transmission mechanism can be determined. gmax It serves as the primary evaluation indicator.

[0062] Second evaluation indicator (maximum difference in transmission output speed Δn) pc.max )

[0063] In this embodiment, in order to obtain the maximum difference in transmission output speed Δn pc.max Perform as follows:

[0064] First, the transmission output speed at each moment during the torque converter lock-up process is monitored using a hydraulic automatic transmission. Where i represents the current gear and j represents the moment during the transmission lock-up process.

[0065] Secondly, based on the corresponding transmission output speed at each moment The maximum difference between the output speeds of the transmissions is determined by taking the absolute value of the difference between them, and is used as the second evaluation index.

[0066] Specifically, the output speeds of the transmission at each time point are subtracted from each other, for example, in, Let k represent the transmission output speed at another moment during the torque converter lock-up process, where k = 1, 2, 3… The maximum difference Δn between the transmission output speeds at each moment can be determined by taking the absolute value of the difference between them. pc.max As the second evaluation indicator.

[0067] As described above, the maximum speed ratio difference Δi of the planetary transmission mechanism is... gmaxMaximum difference in transmission output speed Δn pc.max Both can be used as evaluation indicators for the lock-up impact torque of the torque converter. The following section introduces the use of the maximum speed ratio difference Δi of the planetary transmission mechanism. gmax Maximum difference in transmission output speed Δn pc.max The evaluation process.

[0068] In the specific evaluation process, the maximum speed ratio difference Δi of the planetary transmission mechanism gmax Whether it is greater than the design threshold C, the design threshold C in this embodiment is, for example, 0.02, but it does not constitute a limitation. The specific value can be determined according to the actual situation.

[0069] If Δi gmax If the value is greater than C, then the maximum speed ratio difference Δi of the planetary transmission mechanism is used. gmax Maximum difference in transmission output speed Δn pc.max The torque converter lock-up impact torque is evaluated jointly; among which, if the maximum difference in the speed ratio of the planetary transmission mechanism Δi during the torque converter lock-up process is considered... gmax If the values ​​are different, then the maximum difference in the speed ratio of the planetary transmission mechanism is Δi. gmax The larger the value, the greater the torque converter lock-up impact torque; if the maximum speed ratio difference Δi of the planetary transmission mechanism during the torque converter lock-up process... gmax If the values ​​are the same, then the maximum difference in transmission output speed is Δn. pc.max The larger the value, the greater the torque converter lock-up impact torque.

[0070] If Δi gmax If ≤C, then the maximum difference in transmission output speed Δn is used alone. pc.max Evaluate the torque converter lock-up impact torque; among which, the maximum difference in transmission output speed Δn pc.max The larger the value, the greater the torque converter lock-up impact torque.

[0071] It is worth noting that the speed ratio change of the planetary transmission mechanism caused by the torque converter lock-up impact torque is dissipated as heat generated by the sliding friction of the clutch friction pair and is not actually transmitted to the vehicle occupants through torque disturbance. Therefore, during the torque converter lock-up process, the maximum difference in transmission output speed Δn can still be transmitted. pc.max As the only objective evaluation indicator of the impact of torque converter lock-up shock on vehicle ride comfort, it corresponds to the subjective feelings of the occupants.

[0072] Based on the same inventive concept, the following embodiments describe an evaluation system for torque converter lock-up impact, see below. Figure 4 The system includes:

[0073] Monitoring module 401 is used to monitor the torque converter turbine speed and the transmission output speed;

[0074] The first determining module 402 is used to determine a first evaluation index by combining the torque converter turbine speed and the transmission output speed, and to determine a second evaluation index based on the transmission output speed.

[0075] Evaluation module 403 is used to evaluate the torque converter lock-up impact torque by combining the first evaluation index and the second evaluation index, or by using the second evaluation index alone.

[0076] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0077] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for evaluating torque converter lock-up impact, characterized in that, The method includes: Monitoring the torque converter turbine speed and transmission output speed specifically includes: using a hydraulic automatic transmission to monitor the transmission output speed at various moments during the torque converter lock-up process. Torque converter turbine speeds at various moments during the torque converter lock-up process ;in, Indicates the current gear. Indicates the point in time during the transmission lock-up process; The first evaluation index is determined by combining the torque converter turbine speed and the transmission output speed, specifically including: according to the formula Obtain the speed ratio of the planetary transmission mechanism at each time point. ;in, This represents the theoretical gear ratio corresponding to the current gear of the hydraulic automatic transmission when the torque converter is locked, and is a fixed value; it is based on the gear ratio of the planetary transmission mechanism at each moment. By subtracting the values ​​from each other and taking the absolute value, the maximum difference in speed ratios of the planetary transmission mechanism can be determined. As the first evaluation index; and, The second evaluation index is determined based on the transmission output speed, specifically including: the transmission output speed at each time point. The maximum difference between the output speeds of the transmissions is determined by taking the absolute value of the difference between them. As the second evaluation indicator; Evaluating the torque converter lock-up impact torque by combining the first evaluation index and the second evaluation index, or by using the second evaluation index alone, specifically includes: determining the maximum difference in speed ratio of the planetary transmission mechanism. Is it greater than the design threshold? ;like Then, the maximum difference in speed ratio of the planetary transmission mechanism is used. Maximum difference in transmission output speed The torque converter lock-up impact torque is evaluated jointly; wherein, if the maximum difference in the speed ratio of the planetary transmission mechanism during the torque converter lock-up process is... If the values ​​are different, then the maximum difference in the speed ratio of the planetary transmission mechanism is... The larger the value, the greater the torque converter lock-up impact torque; if the maximum difference in the speed ratio of the planetary transmission mechanism during the torque converter lock-up process is... If the values ​​are the same, then the maximum difference in the output speed of the transmission is... The larger the value, the greater the torque converter lock-up impact torque; if Then, the maximum difference in output speed of the transmission is used alone. The torque converter lock-up impact torque is evaluated; wherein, the maximum difference in the output speed of the transmission is also evaluated. The larger the value, the greater the lock-up impact torque of the torque converter.

2. The method as described in claim 1, characterized in that, The second evaluation index is also used to evaluate the sole evaluation index of the impact of the torque converter lock-up shock on vehicle ride comfort.

3. An evaluation system for torque converter lock-up impact, characterized in that, The system includes: The monitoring module is used to monitor the torque converter turbine speed and the transmission output speed. Specifically, it includes monitoring the transmission output speed at various moments during the torque converter lock-up process using a hydraulic automatic transmission. Torque converter turbine speeds at various moments during the torque converter lock-up process ;in, Indicates the current gear. Indicates the point in time during the transmission lock-up process; The first determining module is used to determine a first evaluation index by combining the torque converter turbine speed and the transmission output speed, specifically including: according to the formula Obtain the speed ratio of the planetary transmission mechanism at each time point. ;in, This represents the theoretical gear ratio corresponding to the current gear of the hydraulic automatic transmission when the torque converter is locked, and is a fixed value; it is based on the gear ratio of the planetary transmission mechanism at each moment. By subtracting the values ​​from each other and taking the absolute value, the maximum difference in speed ratios of the planetary transmission mechanism can be determined. The first evaluation index is used as the evaluation index; and the second evaluation index is determined based on the transmission output speed, specifically including: based on the transmission output speed at each time point. The maximum difference between the output speeds of the transmissions is determined by taking the absolute value of the difference between them. As the second evaluation indicator; The evaluation module is used to evaluate the torque converter lock-up impact torque by combining the first evaluation index and the second evaluation index, or by using the second evaluation index alone. Specifically, it includes: determining the maximum difference in the speed ratio of the planetary transmission mechanism. Is it greater than the design threshold? ;like Then, the maximum difference in speed ratio of the planetary transmission mechanism is used. Maximum difference in transmission output speed The torque converter lock-up impact torque is evaluated jointly; wherein, if the maximum difference in the speed ratio of the planetary transmission mechanism during the torque converter lock-up process is... If the values ​​are different, then the maximum difference in the speed ratio of the planetary transmission mechanism is... The larger the value, the greater the torque converter lock-up impact torque; if the maximum difference in the speed ratio of the planetary transmission mechanism during the torque converter lock-up process is... If the values ​​are the same, then the maximum difference in the output speed of the transmission is... The larger the value, the greater the torque converter lock-up impact torque; if Then, the maximum difference in output speed of the transmission is used alone. The torque converter lock-up impact torque is evaluated; wherein, the maximum difference in the output speed of the transmission is also evaluated. The larger the value, the greater the lock-up impact torque of the torque converter.

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