A method and apparatus for determining clutch pressure

Abstract

The embodiment of the application provides a kind of clutch pressure determination method and device, method includes: determining the target speed difference between clutch and engine, obtains the first demand pressure when clutch is in microslip state and the second demand pressure when target speed difference, according to the friction coefficient compensation coefficient of first demand pressure and second demand pressure determination clutch, obtain the actual demand pressure when clutch is in real-time working state, according to actual demand pressure and friction coefficient compensation coefficient determine the final demand pressure when clutch is in real-time working state, can be calculated according to the demand pressure of different state and obtain the friction coefficient compensation coefficient of clutch under target speed difference, and then according to the actual demand pressure under current target speed difference and friction coefficient compensation coefficient determines final demand pressure, realizes the accurate pressure of clutch, so that clutch carries out accurate transmission torque, improve the transmission torque performance of clutch, correspondingly improve the performance of vehicle.

Description

Technical Field

[0001] This application relates to the field of vehicles, and more particularly to a method and apparatus for determining clutch pressure. Background Technology

[0002] With the rapid development of the automotive industry, the variety of automotive products is also increasing. One crucial component of any vehicle is the clutch, and its performance is paramount. Specifically, the quality of the clutch's torque transmission characteristics directly affects the accuracy of torque transmission, thus impacting the overall performance of the vehicle.

[0003] In practical applications, torque transmission is achieved by applying a certain pressure to the clutch. Therefore, applying appropriate pressure can result in higher torque transmission accuracy. Thus, how to apply appropriate pressure to the clutch during actual driving is a problem that urgently needs to be solved. Summary of the Invention

[0004] This application provides a method and apparatus for determining clutch pressure, which can obtain the final required pressure of the clutch in real-time working state, transmit more accurate torque, and improve vehicle performance.

[0005] This application provides a method for determining clutch pressure, the method comprising:

[0006] Determine the target speed difference between the clutch and the engine;

[0007] Obtain the first required pressure when the clutch is in a state of slight slippage and the second required pressure when it is in the target speed difference;

[0008] The friction coefficient compensation coefficient of the clutch is determined based on the first demand pressure and the second demand pressure.

[0009] Obtain the actual required pressure when the clutch is in real-time operating condition;

[0010] The final required pressure of the clutch when it is in the real-time operating state is determined based on the actual required pressure and the friction coefficient compensation coefficient.

[0011] Optionally, obtaining the first required pressure when the clutch is in a state of slight slippage and the second required pressure when it is in the target speed difference includes:

[0012] Obtain the first required torque when the clutch is in real-time operating state;

[0013] Based on the first correspondence between the first required torque and the first required pressure when the clutch is in the micro-slipping state, the first required pressure when the clutch is in the micro-slipping state is determined.

[0014] The second demand pressure of the clutch at the target speed difference is determined based on the second correspondence between the first demand torque and the second demand pressure at the target speed difference.

[0015] Optionally, obtaining the actual required pressure when the clutch is in real-time operating state includes:

[0016] Based on the third correspondence between the first required torque and the actual required pressure when the clutch is in the real-time operating state, the actual required pressure when the clutch is in the real-time operating state is determined.

[0017] Optionally, the method further includes:

[0018] Compared to the clutch being in a state of slight slippage, the coefficient of friction is determined when there is a difference in target speed under the same demand pressure;

[0019] Based on the clutch torque transmission equation, determine the required torque at different target speed differences under the same required pressure.

[0020] Optionally, determining the friction coefficient compensation coefficient of the clutch based on the first demand pressure and the second demand pressure includes:

[0021] The ratio of the second demand pressure to the first demand pressure is determined as the friction coefficient compensation coefficient of the clutch.

[0022] Optionally, determining the final required pressure of the clutch when it is in the real-time operating state based on the actual required pressure and the friction coefficient compensation coefficient includes:

[0023] The product of the actual required pressure and the friction coefficient compensation coefficient is determined as the final required pressure of the clutch when it is in the real-time operating state.

[0024] This application provides a clutch pressure determining device, the device comprising:

[0025] The first determining unit is used to determine the target speed difference between the clutch and the engine;

[0026] The first acquisition unit is used to acquire the first required pressure when the clutch is in a micro-slipping state and the second required pressure when it is in the target speed difference.

[0027] The second determining unit is used to determine the friction coefficient compensation coefficient of the clutch based on the first demand pressure and the second demand pressure.

[0028] The second acquisition unit is used to acquire the actual required pressure when the clutch is in real-time working state;

[0029] The third determining unit is used to determine the final demand pressure of the clutch when it is in the real-time working state based on the actual demand pressure and the friction coefficient compensation coefficient.

[0030] Optionally, the first acquisition unit is specifically used for:

[0031] Obtain the first required torque when the clutch is in real-time operating state;

[0032] Based on the first correspondence between the first required torque and the first required pressure when the clutch is in the micro-slipping state, the first required pressure when the clutch is in the micro-slipping state is determined.

[0033] The second demand pressure of the clutch at the target speed difference is determined based on the second correspondence between the first demand torque and the second demand pressure at the target speed difference.

[0034] Optionally, the second acquisition unit is specifically used for:

[0035] Based on the third correspondence between the first required torque and the actual required pressure when the clutch is in the real-time operating state, the actual required pressure when the clutch is in the real-time operating state is determined.

[0036] Optionally, the device further includes a fourth determining unit;

[0037] The fourth determining unit is used for:

[0038] Compared to the clutch being in a state of slight slippage, the coefficient of friction is determined when there is a difference in target speed under the same demand pressure;

[0039] Based on the clutch torque transmission equation, determine the required torque at different target speed differences under the same required pressure.

[0040] This application provides a method for determining clutch pressure. The method includes: determining a target speed difference between the clutch and the engine; obtaining a first required pressure when the clutch is in a slightly slipping state and a second required pressure when it is at the target speed difference; determining a friction coefficient compensation coefficient of the clutch based on the first and second required pressures; obtaining the actual required pressure of the clutch when it is in a real-time operating state; and determining the final required pressure of the clutch when it is in a real-time operating state based on the actual required pressure and the friction coefficient compensation coefficient. In other words, since there is a target speed difference between the clutch and the engine, the required pressure of the clutch is different in different states. The friction coefficient compensation coefficient of the clutch under the target speed difference can be calculated based on the required pressure under different states. Then, the final required pressure is determined based on the actual required pressure under the current target speed difference and the friction coefficient compensation coefficient, thereby achieving precise pressure application to the clutch so that the clutch can transmit torque accurately, improve the torque transmission performance of the clutch, and correspondingly improve the performance of the vehicle. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application, 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 some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 A flowchart illustrating a method for determining clutch pressure provided in an embodiment of this application;

[0043] Figure 2 A schematic diagram of the pressure-friction torque relationship provided in an embodiment of this application;

[0044] Figure 3 This is a structural block diagram of a clutch pressure determining device provided in an embodiment of this application. Detailed Implementation

[0045] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present application.

[0046] With the rapid development of the automotive industry, the variety of automotive products is also increasing. One crucial component of any vehicle is the clutch, and its performance is paramount. Specifically, the quality of the clutch's torque transmission characteristics directly affects the accuracy of the frictional torque it transmits, thus impacting the overall performance of the vehicle. However, many factors influence the clutch's torque transmission accuracy, such as temperature, lubrication flow rate, pressure, and the speed difference between the clutch and the engine.

[0047] In practical applications, a certain pressure is applied to the clutch to achieve frictional torque transmission. Therefore, applying appropriate pressure can make the clutch torque transmission accuracy higher. The clutch pressure can usually be determined using the clutch pressure-friction torque relationship diagram (Torque Map). However, this Torque Map does not take into account the influence of the speed difference between the clutch and the engine. This leads to inaccurate clutch pressure application and inaccurate clutch torque transmission under large speed differences, resulting in poor clutch shifting performance.

[0048] Therefore, how to apply appropriate pressure to the clutch during actual driving to achieve high torque transmission accuracy is an urgent problem to be solved.

[0049] Based on this, this application provides a method for determining clutch pressure. The method includes: determining a target speed difference between the clutch and the engine; obtaining a first required pressure when the clutch is in a micro-slipping state and a second required pressure when it is in the target speed difference; determining a friction coefficient compensation coefficient of the clutch based on the first and second required pressures; obtaining the actual required pressure of the clutch in a real-time operating state; and determining the final required pressure of the clutch in the real-time operating state based on the actual required pressure and the friction coefficient compensation coefficient. In other words, since there is a target speed difference between the clutch and the engine, the required pressure of the clutch is different in different states. The friction coefficient compensation coefficient of the clutch under the target speed difference can be calculated based on the required pressure under different states. Then, the final required pressure is determined based on the actual required pressure under the current target speed difference and the friction coefficient compensation coefficient, thereby achieving precise pressure application to the clutch so that the clutch can transmit torque accurately, improve the torque transmission performance of the clutch, and correspondingly improve the performance of the vehicle.

[0050] To better understand the technical solution and effects of this application, the specific embodiments will be described in detail below with reference to the accompanying drawings.

[0051] See Figure 1 The figure is a flowchart of a clutch pressure determination method provided in an embodiment of this application.

[0052] The clutch pressure determination method provided in this embodiment includes the following steps:

[0053] S101, determine the target speed difference between the clutch and the engine.

[0054] In the embodiments of this application, during the driving process of the vehicle, there may be a speed difference between the clutch and the engine. For example, when shifting gears, there may be a large speed difference between the clutch and the engine.

[0055] Specifically, the target speed difference between the clutch currently engaged with the engine and the engine can be determined.

[0056] In practical applications, the target speed difference is usually greater than 20 revolutions per minute (rpm). A target speed difference of 20 rpm is for the clutch to be in a state of slight slippage.

[0057] S102, obtain the first required pressure when the clutch is in a state of slight slippage and the second required pressure when it is in a state of target speed difference.

[0058] In the embodiments of this application, since the clutch requires different pressures when it is in different states, the first required pressure when the clutch is in a state of slight slippage and the second required pressure when it is in a state of target speed difference can be obtained respectively. The first required pressure and the second required pressure correspond to the same required torque, that is, the same required torque corresponds to different required pressures when the clutch and the engine are in different speed differences.

[0059] Specifically, the first required torque when the clutch is in real-time operating condition can be obtained. Based on the first correspondence between the first required torque and the first required pressure when in a state of slight slippage, the first required pressure when the clutch is in a state of slight slippage can be determined. Based on the second correspondence between the first required torque and the second required pressure when at the target speed difference, the second required pressure when the clutch is at the target speed difference can be determined. In other words, after obtaining the first required torque in real-time operating condition, the first required pressure and the second required pressure under the first required torque in a state of slight slippage and at the target speed difference can be determined, i.e., the required pressure under the same required torque in different states can be obtained.

[0060] Specifically, when obtaining the first required torque (CmndTorq) under real-time operating conditions, since there are many real-time operating conditions when the vehicle is running, the first required torque calculated under each operating condition is different. The automatic transmission control unit (TCU) can be used to calculate the first required torque under each operating condition in real time.

[0061] In practical applications, when there is a speed difference between the clutch and the engine, that is, when the clutch is in different states, the same required torque may correspond to different required pressures, and the same required pressure may correspond to different required torques. This is because the friction coefficient of the clutch is different when it is at different target speed differences under the same required pressure.

[0062] Specifically, under different target speed differences and different demand pressures, the friction coefficient deviates from the micro-slip friction state. The table below shows the friction coefficient deviation, where the horizontal axis represents the target speed difference in rpm, and the vertical axis represents the demand pressure in bar. 20 rpm corresponds to the micro-slip friction state, where the friction coefficient is used as the base, and the deviation value (Ofst) is 0. The deviation values ​​for other target speed differences are the Ofst values ​​of the friction coefficient at the current speed difference relative to the friction coefficient under the micro-slip friction state.

[0063]

[0064]

[0065] As shown in the table above, if the friction coefficient under micro-slip friction can be calculated, the friction coefficient under different target speed differences and different demand pressures can be calculated by using the friction coefficient offset values ​​under different target speed differences and different demand pressures.

[0066] The pressure-friction torque relationship diagram under micro-slip friction conditions can be used as a reference. Figure 2 As shown, the required torque under different required pressures in the micro-slip friction state is determined, and then the friction coefficient under different required torques in the micro-slip friction state is determined according to the clutch torque transmission equation.

[0067] The torque transmission equation of the clutch is T=μrmzpA, where μ represents the friction coefficient, rm represents the equivalent radius, z represents the number of friction pairs, p represents the required pressure, and A represents the friction area.

[0068] The friction coefficients under different demand pressures in a state of slight slippage can be calculated using the Torque Map and the clutch torque equation, as shown in the table below:

[0069]

[0070] In the embodiments of this application, the friction coefficient under a micro-slip friction state is obtained. Combined with the offset value of different target speed differences compared to the micro-slip friction state, the friction coefficients under different target speed differences and different pressures can be obtained, as shown in the table below:

[0071]

[0072]

[0073] In the embodiments of this application, since the friction coefficient of the clutch is different at different target speed differences under the same demand pressure, the demand torque is also different at different target speed differences under the same demand pressure. Specifically, compared to a clutch in a slightly slipping state, after determining the friction coefficient at different target speed differences under the same demand pressure, the demand torque at different target speed differences under the same demand pressure is determined according to the clutch torque transmission equation.

[0074] Based on the friction coefficient table and clutch torque transmission equation under different target speed differences and pressures, the required torque table under different target speed differences and pressures is obtained:

[0075]

[0076] In practical applications, after obtaining the first required torque CmndTorq under real-time working conditions, the first required pressure CmndPress_MicrSlp and the second required pressure CmndPress_CurrSlp can be determined based on the required torque tables under different target speed differences and different pressures.

[0077] As an example, the first required torque CmndTorq is 222 Nm, and at 20 rpm under slight slippage conditions, according to the required torque table under different target speed differences and different pressures, the first required pressure CmndPress_MicrSlp is 19 bar.

[0078] As another example, the first required torque CmndTorq is 283 Nm, and the second required pressure CmndPress_CurrSlp is 19 bar when the target speed difference is 1000 rpm, according to the required torque table for different target speed differences and different pressures.

[0079] S103, determine the friction coefficient compensation coefficient of the clutch based on the first demand pressure and the second demand pressure.

[0080] In the embodiments of this application, after determining the first demand pressure and the second demand pressure according to the demand torque table under different target speed differences and different pressures, the friction coefficient compensation coefficient of the clutch can be determined based on the first demand pressure and the second demand pressure.

[0081] Specifically, the ratio of the second demand pressure CmndPress_MicrSlp to the first demand pressure CmndPress_CurrSlp can be determined as the friction coefficient compensation coefficient FrictionFactor of the clutch, that is, FrictionFactor=CmndPress_CurrSlp / CmndPress_MicrSlp.

[0082] S104, obtain the actual required pressure when the clutch is in real-time working state.

[0083] In the embodiments of this application, after obtaining the friction coefficient compensation coefficient of the clutch under different target speed differences and different demand pressures, the friction coefficient compensation coefficient can be used to compensate for the current demand pressure. Therefore, the actual demand pressure when the clutch is in the current real-time working state can be obtained first.

[0084] Specifically, the actual required pressure of the clutch in real-time operation can be determined based on the third correspondence between the first required torque and the actual required pressure when the clutch is in real-time operation. This third correspondence can be a Torque Map.

[0085] In other words, the actual required pressure CmndPres_T2P can be determined based on the calculated first required torque CmndTorq of the clutch under the current operating conditions and the Torque Map.

[0086] S105 determines the final demand pressure of the clutch when it is in real-time working state based on the actual demand pressure and the friction coefficient compensation coefficient.

[0087] In the embodiments of this application, after obtaining the actual required pressure and the friction coefficient compensation coefficient, the final required pressure when the clutch is in real-time working state can be determined based on the actual required pressure and the friction coefficient compensation coefficient.

[0088] Specifically, the product of the actual demand pressure CmndPres_T2P and the friction coefficient compensation coefficient FrictionFactor can be determined as the final demand pressure CmndPres_Fnl when the clutch is in real-time working state, that is, CmndPres_Fnl=CmndPres_T2P×FrictionFactor.

[0089] Therefore, the clutch pressure determination method provided in this application adjusts the clutch pressure in real time according to the clutch characteristics and the current working condition of the clutch, ensuring that the clutch accurately transmits the required torque at all times.

[0090] This application provides a method for determining clutch pressure. The method includes: determining a target speed difference between the clutch and the engine; obtaining a first required pressure when the clutch is in a slightly slipping state and a second required pressure when it is at the target speed difference; determining a friction coefficient compensation coefficient of the clutch based on the first and second required pressures; obtaining the actual required pressure of the clutch when it is in a real-time operating state; and determining the final required pressure of the clutch when it is in a real-time operating state based on the actual required pressure and the friction coefficient compensation coefficient. In other words, since there is a target speed difference between the clutch and the engine, the required pressure of the clutch is different in different states. The friction coefficient compensation coefficient of the clutch under the target speed difference can be calculated based on the required pressure under different states. Then, the final required pressure is determined based on the actual required pressure under the current target speed difference and the friction coefficient compensation coefficient, thereby achieving precise pressure application to the clutch so that the clutch can transmit torque accurately, improve the torque transmission performance of the clutch, and correspondingly improve the performance of the vehicle.

[0091] Based on the clutch pressure determination method provided in the above embodiments, this application also provides a clutch pressure determination device, the working principle of which will be described in detail below with reference to the accompanying drawings.

[0092] See Figure 3 The figure is a structural block diagram of a clutch pressure determining device provided in an embodiment of this application.

[0093] The clutch pressure determining device 300 provided in this embodiment includes:

[0094] The first determining unit 310 is used to determine the target speed difference between the clutch and the engine;

[0095] The first acquisition unit 320 is used to acquire the first required pressure when the clutch is in a micro-slipping state and the second required pressure when it is in the target speed difference.

[0096] The second determining unit 330 is used to determine the friction coefficient compensation coefficient of the clutch based on the first demand pressure and the second demand pressure.

[0097] The second acquisition unit 340 is used to acquire the actual required pressure when the clutch is in real-time working state;

[0098] The third determining unit 350 is used to determine the final demand pressure of the clutch when it is in the real-time working state based on the actual demand pressure and the friction coefficient compensation coefficient.

[0099] Optionally, the first acquisition unit is specifically used for:

[0100] Obtain the first required torque when the clutch is in real-time operating state;

[0101] Based on the first correspondence between the first required torque and the first required pressure when the clutch is in the micro-slipping state, the first required pressure when the clutch is in the micro-slipping state is determined.

[0102] The second demand pressure of the clutch at the target speed difference is determined based on the second correspondence between the first demand torque and the second demand pressure at the target speed difference.

[0103] Optionally, the second acquisition unit is specifically used for:

[0104] Based on the third correspondence between the first required torque and the actual required pressure when the clutch is in the real-time operating state, the actual required pressure when the clutch is in the real-time operating state is determined.

[0105] Optionally, the device further includes a fourth determining unit;

[0106] The fourth determining unit is used for:

[0107] Compared to the clutch being in a state of slight slippage, the coefficient of friction is determined when there is a difference in target speed under the same demand pressure;

[0108] Based on the clutch torque transmission equation, determine the required torque at different target speed differences under the same required pressure.

[0109] Optionally, the second determining unit is specifically used for:

[0110] The ratio of the second demand pressure to the first demand pressure is determined as the friction coefficient compensation coefficient of the clutch.

[0111] Optionally, the third determining unit is specifically used for:

[0112] The product of the actual required pressure and the friction coefficient compensation coefficient is determined as the final required pressure when the clutch is in the real-time operating state.

[0113] When describing elements of various embodiments of this application, the articles “a,” “an,” “this,” and “described” are all intended to indicate that there are one or more elements. The words “comprising,” “including,” and “having” are inclusive and mean that there may be other elements in addition to those listed.

[0114] It should be noted that those skilled in the art will understand that all or part of the processes in the above method embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0115] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on its differences from other embodiments. In particular, the device embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. The device embodiments described above are merely illustrative. The units and modules described as separate components may or may not be physically separate. Furthermore, some or all of the units and modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0116] The above description is only a specific embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for determining the pressure of a clutch, characterized in that, The method includes: Determine the target speed difference between the clutch and the engine; Obtain the first required pressure when the clutch is in a state of slight slippage and the second required pressure when it is in the target speed difference; The ratio of the second demand pressure to the first demand pressure is determined as the friction coefficient compensation coefficient of the clutch. Obtain the actual required pressure when the clutch is in real-time operating condition; The product of the actual required pressure and the friction coefficient compensation coefficient is determined as the final required pressure when the clutch is in the real-time operating state.

2. The method according to claim 1, characterized in that, The process of obtaining the first required pressure when the clutch is in a state of slight slippage and the second required pressure when it is in the target speed difference includes: Obtain the first required torque when the clutch is in real-time operating state; Based on the first correspondence between the first required torque and the first required pressure when the clutch is in the micro-slipping state, the first required pressure when the clutch is in the micro-slipping state is determined. The second demand pressure of the clutch at the target speed difference is determined based on the second correspondence between the first demand torque and the second demand pressure at the target speed difference.

3. The method according to claim 2, characterized in that, The actual required pressure when the clutch is in real-time operating state includes: Based on the third correspondence between the first required torque and the actual required pressure when the clutch is in the real-time operating state, the actual required pressure when the clutch is in the real-time operating state is determined.

4. The method according to any one of claims 1-3, characterized in that, The method further includes: Compared to the clutch being in a state of slight slippage, the coefficient of friction is determined when there is a difference in target speed under the same demand pressure; Based on the clutch torque transmission equation, determine the required torque at different target speed differences under the same required pressure.

5. A clutch pressure determining device, characterized in that, The device includes: The first determining unit is used to determine the target speed difference between the clutch and the engine; The first acquisition unit is used to acquire the first required pressure when the clutch is in a micro-slipping state and the second required pressure when it is in the target speed difference. The second determining unit is used to determine the ratio of the second demand pressure to the first demand pressure as the friction coefficient compensation coefficient of the clutch. The second acquisition unit is used to acquire the actual required pressure when the clutch is in real-time working state; The third determining unit is used to determine the product of the actual demand pressure and the friction coefficient compensation coefficient as the final demand pressure when the clutch is in the real-time working state.

6. The apparatus according to claim 5, characterized in that, The first acquisition unit is specifically used for: Obtain the first required torque when the clutch is in real-time operating state; Based on the first correspondence between the first required torque and the first required pressure when the clutch is in the micro-slipping state, the first required pressure when the clutch is in the micro-slipping state is determined. The second demand pressure of the clutch at the target speed difference is determined based on the second correspondence between the first demand torque and the second demand pressure at the target speed difference.

7. The apparatus according to claim 6, characterized in that, The second acquisition unit is specifically used for: Based on the third correspondence between the first required torque and the actual required pressure when the clutch is in the real-time operating state, the actual required pressure when the clutch is in the real-time operating state is determined.

8. The apparatus according to any one of claims 5-7, characterized in that, The device further includes a fourth determining unit; The fourth determining unit is used for: Compared to the clutch being in a state of slight slippage, the coefficient of friction is determined when there is a difference in target speed under the same demand pressure; Based on the clutch torque transmission equation, determine the required torque at different target speed differences under the same required pressure.

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