Adaptive Method for Clutch Engagement Point

Abstract

The present invention provides an adaptive method for the clutch engagement point, which is applicable to the dual-clutch transmission system of an automobile. The method includes: when the status information of the dual-clutch transmission system and the driving information of the automobile both meet the preset adaptive activation conditions, obtaining multiple groups of status information and driving information that meet the adaptive activation conditions, and calculating the average pressure value of the actual pressure of the clutch corresponding to each group of information and the average torque value of the input torque of the dual-clutch transmission; determining the engagement point pressure compensation value according to the average torque value, the preset torque model, and the average pressure value; and compensating the actual pressure of the clutch corresponding to the clutch engagement point according to the engagement point pressure compensation value. This solution adjusts the pressure of the clutch engagement point by transmitting all the average pressure values and average torque values that meet the adaptive conditions within a certain range of torque, which can make the pressure value corresponding to the clutch engagement point more accurate, and further make the torque transmitted by the clutch more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of clutch torque control, and particularly relates to an adaptive method for a clutch engagement point. Background Art

[0002] Due to its fast shifting speed, high comfort, and ability to provide uninterrupted power output, the dual-clutch transmission has become the focus of research and development by major automobile manufacturers.

[0003] For a dual-clutch transmission, the control of the clutch has a great impact on the smoothness of the vehicle driving. For the clutch, the engagement point of the clutch is one of the most important basic characteristic points of the clutch. This engagement point (also known as the meshing point) can transmit a relatively low torque. If the engagement point is inaccurate, it will cause the torque of the clutch in the low-torque stage to not match the engine torque, resulting in poor smoothness of the vehicle driving and affecting the driving experience. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem in the prior art that the engagement point of the clutch is inaccurate and affects the driving experience.

[0005] To solve the above problems, an embodiment of the present invention discloses an adaptive method for a clutch engagement point, which is applicable to a dual-clutch transmission system of an automobile. The dual-clutch transmission system includes a dual-clutch transmission, an engine, and a clutch; wherein, the clutch is arranged between the dual-clutch transmission and the engine to cut off or connect the power transmission between the dual-clutch transmission and the engine; the adaptive method for the clutch engagement point includes the following steps:

[0006] S1: Obtain the state information of the dual-clutch transmission system and the driving information of the automobile, and determine whether the state information of the dual-clutch transmission system and the driving information of the automobile both meet the preset adaptive activation conditions;

[0007] If so, execute step S2;

[0008] If not, continue to determine whether the state information of the dual-clutch transmission system and the driving information of the automobile both meet the preset adaptive activation conditions;

[0009] S2: Obtain multiple groups of state information and driving information that meet the adaptive activation conditions, and calculate the average pressure value of the actual pressure of the clutch corresponding to each group of state information and driving information, and the average torque value of the input torque of the dual-clutch transmission;

[0010] S3: Determine the engagement point pressure compensation value according to the average torque value, the preset torque model, and the average pressure value;

[0011] S4: Compensate the actual pressure of the clutch corresponding to the clutch engagement point according to the engagement point pressure compensation value;

[0012] S5: Repeat steps S1 to S4 until the actual pressure corresponding to the clutch engagement point reaches the preset condition.

[0013] Adopting the above solution, under the condition of meeting the adaptive activation condition, record the average pressure and average torque of all points within a certain torque range. And when the number of records reaches a certain threshold, adaptively adjust the actual pressure corresponding to the clutch engagement point synchronously according to the ratio. It can make the pressure value corresponding to the clutch engagement point more accurate, and then make the torque transmitted by the clutch more accurate, improving the driving smoothness.

[0014] According to another specific embodiment of the present invention, in the adaptive method for the clutch engagement point disclosed in the embodiment of the present invention, in step S1, the state information of the dual-clutch transmission system includes the control state of the clutch, the input torque of the dual-clutch transmission, the temperature of the oil in the dual-clutch transmission, the temperature of the coolant in the dual-clutch transmission system, the engine speed, the clutch speed, and the engine torque; the driving information of the vehicle includes the current gear and the road surface gradient; and the preset adaptive activation conditions include: the range of the current gear is from the 3rd gear to the 7th gear; the control state of the clutch is the micro-slip friction control state; the range of the input torque of the dual-clutch transmission is from 15 N·m to 30 N·m; the range of the temperature of the oil in the dual-clutch transmission is from 50 °C to 120 °C; the range of the road surface gradient is from 0 to 6%; the difference between the engine speed and the clutch speed ranges from 0 to 30 r / min and lasts for more than 0.5 s within this speed range; the engine torque is stable; and the above conditions need to be met simultaneously.

[0015] Adopting the above solution, during the process of judging the adaptive activation condition, comprehensively considering factors such as the gear, the state of the clutch, the state of the engine, and even considering the influence of the oil temperature, coolant temperature, and road surface gradient, setting strict adaptive activation conditions can make the actual pressure of the clutch and the input torque of the dual-clutch transmission obtained according to the adaptive activation condition more accurate, thereby improving the control accuracy.

[0016] According to another specific embodiment of the present invention, the adaptive method for the clutch engagement point disclosed in the embodiment of the present invention, step S2 includes: obtaining at least 300 groups of state information and driving information that meet the adaptive activation conditions; obtaining the actual pressure of the clutch and the input torque of the dual-clutch transmission corresponding to each group of state information and driving information that meet the adaptive activation conditions; calculating the average pressure value of the actual pressure of the clutch corresponding to each group of state information and driving information that meet the adaptive activation conditions, and calculating the average torque value of the input torque of the dual-clutch transmission corresponding to each group of state information and driving information that meet the adaptive activation conditions.

[0017] Adopting the above solution, restricting the quantity of the state information and driving information that meet the adaptive activation conditions can prevent random errors from affecting the average pressure value and the average torque value, and improve the accuracy of control.

[0018] According to another specific embodiment of the present invention, after step S2 of the adaptive method for the clutch engagement point disclosed in the embodiment of the present invention, it further includes:

[0019] S2’: Storing the average pressure value and the average torque value into the read-only memory of the vehicle.

[0020] According to another specific embodiment of the present invention, after step S2’ of the adaptive method for the clutch engagement point disclosed in the embodiment of the present invention, it further includes:

[0021] S2”: Judging whether both the average pressure value and the average torque value are within a preset reasonable range;

[0022] If so, execute step S3;

[0023] If not, clear all groups of state information and driving information that meet the adaptive activation conditions, clear the average pressure value and the average torque value stored in the read-only memory, and re-execute steps S1 to S2”.

[0024] Adopting the above solution, if any one of the average pressure value and the average torque value is not within the preset reasonable range, adaptive adjustment needs to be performed again. Thus, the problem of inaccurate pressure control of the clutch engagement point caused by unreasonable average pressure value and average torque value is avoided.

[0025] According to another specific embodiment of the present invention, step S3 of the adaptive method for the clutch engagement point disclosed in the embodiment of the present invention includes:

[0026] S31: Obtaining the target pressure of the torque model corresponding to the average torque value according to the average torque value and a preset torque model;

[0027] S32: Calculate the pressure difference between the average pressure value and the target pressure, and use the pressure difference as the pressure compensation value for the bite point.

[0028] According to another specific embodiment of the present invention, in the adaptive method for the clutch bite point disclosed in the embodiment of the present invention, after step S3, it further includes:

[0029] S3': Limit the adaptive step size according to the pressure compensation value for the bite point, the state information of the dual-clutch transmission system, and the driving information of the vehicle to obtain the maximum adjustment step size per time.

[0030] Adopting the above solution to limit the maximum adjustment step size per time avoids the pressure mutation of the clutch bite point caused by excessive adjustment at one time, and solves the problem of the occurrence of mutation points in vehicle control.

[0031] According to another specific embodiment of the present invention, in the adaptive method for the clutch bite point disclosed in the embodiment of the present invention, step S4 further includes: compensating the actual pressure of the clutch corresponding to the clutch bite point according to the pressure compensation value for the bite point and the maximum adjustment step size per time to obtain the compensated pressure of the clutch; and after step S4, it further includes: storing the compensated pressure in the read-only memory of the vehicle.

[0032] According to another specific embodiment of the present invention, in the adaptive method for the clutch bite point disclosed in the embodiment of the present invention, compensating the actual pressure of the clutch corresponding to the clutch bite point according to the pressure compensation value for the bite point and the maximum adjustment step size per time includes:

[0033] Judge whether the pressure compensation value for the bite point is greater than the maximum adjustment step size per time;

[0034] If so, compensate the actual pressure of the clutch bite point according to the maximum adjustment step size per time;

[0035] If not, compensate the actual pressure of the clutch bite point according to the pressure compensation value for the bite point.

[0036] Adopting the above solution can avoid large changes in the pressure of the clutch bite point, resulting in torque mutation and further causing the problem of vehicle driving jerks.

[0037] According to another specific embodiment of the present invention, the adaptive method for the clutch engagement point disclosed in the embodiment of the present invention, step S5 includes: clearing all sets of state information, driving information, average pressure value, and average torque value that meet the adaptive activation conditions in the previous adaptive cycle; repeating steps S1 to S4 to compensate for the compensation pressure of the clutch obtained in the previous adaptive cycle until the actual pressure corresponding to the clutch engagement point reaches a preset condition; and the preset condition includes: the target pressure of the preset torque model corresponding to the average torque value is equal to the average pressure value.

[0038] Adopting the above solution, by continuously compensating for the compensation pressure of the clutch obtained in the previous adaptive cycle, the pressure at the clutch engagement point can quickly reach the target.

[0039] The beneficial effects of the present invention are:

[0040] This solution synchronously and proportionally adjusts the pressure at the clutch engagement point by stably transmitting all average pressure values and average torque values that meet the adaptive conditions within a certain range of torque, enabling the pressure value corresponding to the clutch engagement point to be more accurate. Thus, the torque transmitted by the clutch can be more accurate, the driving smoothness of the whole vehicle is better, and the driving experience is improved. Description of the Drawings

[0041] Figure 1 is a flowchart of the adaptive method for the clutch engagement point provided by the embodiment of the present invention;

[0042] Figure 2 is a structural schematic diagram of the dual-clutch transmission system provided by the embodiment of the present invention.

[0043] Description of the Reference Numerals:

[0044] 1. Dual-clutch transmission; 2. Engine; 3. Clutch. Specific Embodiment

[0045] The following specific embodiments illustrate the embodiments of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiments, this does not mean that the features of this invention are limited to this embodiment. On the contrary, the purpose of introducing the invention in conjunction with the embodiment is to cover other alternatives or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, many specific details will be included in the following description. The present invention can also be implemented without these details. In addition, in order to avoid confusing or obscuring the key points of the present invention, some specific details will be omitted in the description. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0046] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0047] In the description of this embodiment, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "bottom", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention.

[0048] The terms "first", "second", etc. are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0049] In the description of this embodiment, it should also be noted that unless otherwise clearly specified and defined, the terms "arranged", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this embodiment can be understood according to specific circumstances.

[0050] To make the purpose, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the drawings.

[0051] To solve the problem in the prior art that the engagement point of the clutch is inaccurate and affects the driving experience, an adaptive method for the clutch engagement point is provided in the embodiments of the present invention. This adaptive method for the clutch engagement point is applicable to the dual-clutch transmission system of an automobile.

[0052] Specifically, referring to Figure 1 , the adaptive method for the clutch engagement point provided in this embodiment includes the following steps:

[0053] S1: Obtain the state information of the dual-clutch transmission system and the driving information of the automobile, and determine whether both the state information of the dual-clutch transmission system and the driving information of the automobile meet the preset adaptive activation conditions;

[0054] If so, execute step S2;

[0055] If not, continue to determine whether both the state information of the dual-clutch transmission system and the driving information of the automobile meet the preset adaptive activation conditions;

[0056] S2: Obtain multiple groups of state information and driving information that meet the adaptive activation conditions, and calculate the average pressure value of the actual pressure of the clutch corresponding to each group of state information and driving information, and the average torque value of the input torque of the dual-clutch transmission.

[0057] S3: Determine the bite point pressure compensation value according to the average torque value, the preset torque model, and the average pressure value.

[0058] S4: Compensate the actual pressure of the clutch corresponding to the clutch bite point according to the bite point pressure compensation value.

[0059] S5: Repeat steps S1 to S4 until the actual pressure corresponding to the clutch bite point reaches the preset condition.

[0060] Adopting the above solution, under the condition of meeting the adaptive activation condition, record the average pressure and average torque of all points within a certain torque range. And when the number of records reaches a certain threshold, adaptively adjust the actual pressure corresponding to the clutch bite point proportionally. It can make the pressure value corresponding to the clutch bite point more accurate, and then make the torque transmitted by the clutch more accurate, improving the smoothness of driving.

[0061] Next, refer to Figure 1-2 Specifically describe the adaptive method for the clutch bite point provided in this embodiment.

[0062] Before explaining the adaptive method for the clutch bite point, first explain the dual-clutch transmission system of the vehicle.

[0063] Refer to Figure 2 , the dual-clutch transmission system includes a dual-clutch transmission 1, an engine 2, and a clutch 3. The clutch 3 is arranged between the dual-clutch transmission 1 and the engine 2 to cut off or connect the power transmission between the dual-clutch transmission 1 and the engine 2.

[0064] When the clutch 3 is depressed, the transmission device of the engine 2 is disconnected from the wheels, and the power of the engine 2 will not be transmitted to the wheels, so the vehicle will not be driven. When the clutch 3 is released, the transmission device of the engine 2 is connected to the wheels, and the power of the engine 2 is transmitted to the wheels, and the vehicle is driven. The dual-clutch transmission system in this embodiment has no essential difference from the dual-clutch transmission system in the prior art, and will not be elaborated in this embodiment.

[0065] The adaptive method for the clutch bite point provided by the present invention is used to control the pressure of the bite point of the clutch of the dual-clutch transmission system. And this method is preferably applicable to controlling the pressure of the bite point of the wet clutch.

[0066] Among them, the bite point (BP) of the clutch is the point where the clutch transmits a relatively low torque. The torque transmitted at the bite point of a general clutch ranges from 12 N·m to 18 N·m, such as 15 N·m.

[0067] The pressure at the bite point of the clutch refers to the pressure transmitted to the output shaft by the clutch at the bite point.

[0068] First, perform step S1 to obtain the state information of the dual-clutch transmission system and the driving information of the vehicle, and determine whether both the state information of the dual-clutch transmission system and the driving information of the vehicle meet the preset adaptive activation conditions;

[0069] If so, perform step S2;

[0070] If not, continue to determine whether both the state information of the dual-clutch transmission system and the driving information of the vehicle meet the preset adaptive activation conditions.

[0071] Specifically, the state information of the dual-clutch transmission system includes the control state of the clutch, the input torque of the dual-clutch transmission, the temperature of the oil in the dual-clutch transmission, the temperature of the coolant in the dual-clutch transmission system, the engine speed, the clutch speed, and the engine torque.

[0072] Among them, the control state of the clutch can be measured by the engine speed and the clutch speed, that is, it can be measured by a speed sensor and obtained through subsequent calculations. The input torque of the dual-clutch transmission refers to the torque of the input shaft of the transmission and can be measured by a torque sensor. The temperature of the oil in the dual-clutch transmission can be measured by a temperature sensor. The temperature of the coolant can also be measured by a temperature sensor. The engine torque refers to the torque output by the engine and can be measured by a torque sensor.

[0073] The driving information of the vehicle includes the current gear and the road surface gradient.

[0074] Among them, the current gear refers to the current gear of the vehicle and can be measured by a gear sensor. The road surface gradient is also the percentage of the elevation difference between two points on the road surface and its horizontal distance, and can be obtained by measuring and calculating the elevation difference and the distance respectively.

[0075] In this embodiment, the preset adaptive activation conditions include: the current gear range is from the 3rd gear to the 7th gear; the control state of the clutch is the micro-slip friction control state; the input torque range of the dual-clutch transmission is from 15 N·m to 30 N·m; the temperature range of the oil in the dual-clutch transmission is from 50 °C to 120 °C; the road surface gradient range is from 0 to 6%; the difference between the engine speed and the clutch speed ranges from 0 to 30 r / min and lasts for more than 0.5 s within this speed range; and the engine torque is stable.

[0076] It should be noted that the adaptive activation can be activated only when the above adaptive activation conditions are met simultaneously.

[0077] Specifically, the number of gears of the dual-clutch transmission is generally 7. The current gear range from the 3rd gear to the 7th gear means that the current gear is in the 3rd, 4th, 5th, 6th, or 7th gear.

[0078] The micro-slip friction control state refers to the state where the difference between the clutch speed and the engine speed is less than the preset speed threshold. In this embodiment, when the speed difference between the clutch and the engine is from 0 r / min to 30 r / min, the control state of the clutch is the micro-slip friction control state.

[0079] The input torque range of the dual-clutch transmission is from 15 N·m to 30 N·m, which can specifically be 15 N·m, 20 N·m, 25.5 N·m, 30 N·m, or other values within this range.

[0080] The temperature range of the oil in the dual-clutch transmission is from 50 °C to 120 °C, which can specifically be 50 °C, 70 °C, 105 °C, 110.5 °C, 120 °C, or other values within this range.

[0081] The road surface gradient range from 0 to 6% means that the road surface gradient should be less than a certain threshold, such as 6%, 2.5%, or it can also be 0.

[0082] The difference between the engine speed and the clutch speed ranges from 0 to 30 r / min and lasts for more than 0.5 s within this speed range. That is to say, the clutch needs to be in the micro-slip friction control state for at least 0.5 s. For example, it can be 0.5 s, 1 s, or even longer.

[0083] The engine torque being stable means that the torque output by the engine is stable without fluctuations, which can be measured by the real-time change rate of the engine torque. When the change rate of the engine torque exceeds a certain value, it is considered that the engine torque is unstable; otherwise, it is stable.

[0084] Next, execute step S2 to obtain multiple sets of status information and driving information that meet the adaptive activation conditions, and calculate the average pressure value of the actual pressure of the clutch corresponding to each set of status information and driving information, and the average torque value of the input torque of the dual-clutch transmission.

[0085] Specifically, step S2 includes the following steps: First, obtain at least 300 sets of status information and driving information that meet the adaptive activation conditions. After that, obtain the actual pressure of the clutch and the input torque of the dual-clutch transmission corresponding to each set of status information and driving information that meet the adaptive activation conditions. Then, calculate the average pressure value of the actual pressure of the clutch corresponding to each set of status information and driving information that meet the adaptive activation conditions, and calculate the average torque value of the input torque of the dual-clutch transmission corresponding to each set of status information and driving information that meet the adaptive activation conditions.

[0086] In this embodiment, taking obtaining 300 sets of status information and driving information that meet the adaptive activation conditions as an example for illustration. Each time the adaptive condition is met, record the actual pressure of the clutch and the input torque of the dual-clutch transmission that meet the adaptive condition at that time. When 300 sets of the actual pressure of the clutch and the input torque of the dual-clutch transmission are accumulated, average these 300 actual pressures of the clutch to obtain the average pressure value of the actual pressure of the clutch; and average these 300 input torques of the dual-clutch transmission to obtain the average torque value of the input torque of the dual-clutch transmission.

[0087] It should be noted that in this embodiment, the average value of multiple sets of information is obtained to prevent random errors and the accuracy of subsequent calculations. In other embodiments of the present invention, 280, 400, 600 or even more sets of status information and driving information that meet the adaptive activation conditions can also be obtained.

[0088] It should be noted that in this embodiment, after step S2, there is also step S2'.

[0089] S2': Store the average pressure value and the average torque value in the read-only memory of the vehicle.

[0090] Specifically, the read-only memory in this embodiment refers to an Electrically Erasable Programmable Read-Only Memory (EEPROM).

[0091] Preferably, after step S2', there is also step S2".

[0092] S2": Judge whether both the average pressure value and the average torque value are within a preset reasonable range;

[0093] If so, execute step S3;

[0094] If not, clear all groups of status information and driving information that meet the adaptive activation conditions, clear the average pressure value and average torque value stored in the read-only memory, and re-execute steps S1 to S2.”

[0095] It should be noted that the preset reasonable range is related to the hardware characteristics of the dual-clutch transmission and the clutch. In this embodiment, the average pressure value and the average torque value respectively have their corresponding reasonable ranges.

[0096] In this embodiment, as long as any one of the average pressure value and the average torque value is not within the preset reasonable range, it is necessary to clear all the status information, driving information, average pressure value and average torque value that meet the adaptive activation conditions, and then re-execute the adaptive process.

[0097] After that, execute step S3 to determine the bite point pressure compensation value according to the average torque value, the preset torque model, and the average pressure value.

[0098] It should be noted that the torque model is obtained by analyzing and processing the torque curve. For a dry clutch, its torque curve can be determined by the motor pushing the clutch disc to move and the clutch position (displacement). This displacement can usually be measured by the actuator motor. For a wet clutch, its torque curve can be determined by measuring the pressure in the clutch piston chamber to determine the torque that the clutch can transmit. The clutch pressure is directly measured by a sensor. The above torque curves need to be calibrated on the transmission test bench with a special torque sensor, and then tested and verified on the vehicle, and the influencing factors such as temperature are corrected, and finally used as the torque model.

[0099] Specifically, step S3 includes the following steps:

[0100] S31: Obtain the target pressure of the torque model corresponding to the average torque value according to the average torque value and the preset torque model;

[0101] S32: Calculate the pressure difference between the average pressure value and the target pressure, and use the pressure difference as the bite point pressure compensation value.

[0102] That is to say, in this torque model, each torque value has a corresponding pressure. In this embodiment, it is necessary to find the pressure corresponding to the average torque value by using this torque model according to the average torque value, and use this pressure as the target pressure.

[0103] After obtaining the target pressure, the difference between it and the average pressure is the bite point pressure compensation value.

[0104] Preferably, in this embodiment, after step S3, step S3' is further included.

[0105] S3': Limit the adaptive step size according to the bite point pressure compensation value, the state information of the dual-clutch transmission system, and the driving information of the vehicle to obtain the maximum single adjustment step size.

[0106] It should be noted that the maximum single adjustment step size refers to the upper limit of the pressure adjustment of the bite point each time.

[0107] Next, execute step S4 to compensate the actual pressure of the clutch corresponding to the clutch bite point according to the bite point pressure compensation value.

[0108] Specifically, step S4 further includes: compensating the actual pressure of the clutch corresponding to the clutch bite point according to the bite point pressure compensation value and the maximum single adjustment step size to obtain the compensated pressure of the clutch.

[0109] Preferably, after step S4, the following is further included: storing the compensated pressure in the read-only memory of the vehicle.

[0110] More specifically, compensating the actual pressure of the clutch corresponding to the clutch bite point according to the bite point pressure compensation value and the maximum single adjustment step size includes:

[0111] Judge whether the bite point pressure compensation value is greater than the maximum single adjustment step size;

[0112] If so, compensate the actual pressure of the clutch bite point according to the maximum single adjustment step size;

[0113] If not, compensate the actual pressure of the clutch bite point according to the bite point pressure compensation value.

[0114] That is to say, when the pressure compensation value of the bite point is larger than the upper limit of the pressure adjustment of the bite point each time (the maximum single adjustment step size), only add or subtract the upper limit value of the pressure adjustment of the bite point to the actual pressure value of the clutch bite point. When the pressure compensation value of the bite point is smaller than the maximum single adjustment step size, add or subtract the bite point pressure compensation value to the actual pressure value of the clutch bite point.

[0115] In this embodiment, taking the actual pressure of the clutch bite point as a, the maximum single adjustment step size as b, and the bite point pressure compensation value as b' for illustration. When b ≥ b', the actual pressure of the clutch bite point is adjusted to a + b'. When b < b', the actual pressure of the clutch bite point is adjusted to a + b.

[0116] After that, execute step S5, and repeat steps S1 to S4 until the actual pressure corresponding to the clutch bite point reaches the preset condition.

[0117] Specifically, the preset conditions include: the target pressure of the preset torque model corresponding to the average torque value is equal to the average pressure value.

[0118] More specifically, step S5 specifically includes: First, clear all groups of state information, driving information, average pressure value, and average torque value that meet the adaptive activation conditions in the previous adaptive cycle. After that, repeat steps S1 to S4 to compensate for the compensation pressure of the clutch obtained in the previous adaptive cycle until the actual pressure corresponding to the clutch engagement point reaches the preset conditions.

[0119] That is to say, in this embodiment, after compensating the actual pressure of the clutch engagement point once, it is necessary to re-judge whether the adaptive activation conditions are met, accumulate a certain amount of data, and recalculate the average torque value and average pressure value. Then, determine the engagement point pressure compensation value again according to the calculated average torque value and average pressure value required for the second adjustment, and adjust the actual pressure of the clutch engagement point adjusted for the first time according to the re-determined engagement point pressure compensation value.

[0120] Taking the actual pressure of the clutch engagement point after the previous adjustment as a + b, the single maximum adjustment step as b, and the engagement point pressure compensation value as b' for illustration. When b ≥ b', adjust the actual pressure of the clutch engagement point to (a + b) + b'. When b < b', adjust the actual pressure of the clutch engagement point to (a + b) + b. Subsequent adjustments are carried out in the same way.

[0121] In another specific embodiment of the present invention, the adaptive method for the clutch engagement point is as follows:

[0122] Judge whether the adaptive activation conditions for the clutch engagement point are met according to Table 1 below.

[0123] Condition Range The gear position is within a certain range For example (3-7) The clutch is controlled in the micro-slip control state For example, the speed difference is 30 rpm The transmission input torque is within a certain range For example (15-30) The transmission oil temperature is within a certain range For example (50-120) The coolant temperature is within a certain range For example (50-120) The slope is less than a certain threshold For example 5% The speed difference exceeds a certain time within a certain range For example, the speed difference is within 30 rpm for 0.5 s The engine torque is stable The torque is stable without fluctuation

[0124] Table 1 Adaptive Activation Conditions for Clutch Engagement Point

[0125] When the adaptive conditions for the clutch engagement point are met, accumulate the number of times that meet the above adaptive activation conditions. Calculate the average value of the corresponding actual pressures of the clutch for all times That is, the average pressure value. Calculate the average value of the input torques of the gearbox corresponding to all times That is, the average torque value, and store these values in the corresponding read-only memory (EERPOM).

[0126] If the cumulative number of times in the above EEPROM does not reach a certain threshold, such as 300, then continue to return and judge whether it meets the adaptive activation conditions in Table 1 above.

[0127] If the cumulative number of times reaches the threshold, it is necessary to continue to judge the average value of the actual pressure of the clutch stored in the EEPROM whether it is within a reasonable range. If it is not within a reasonable range, this adaptive adjustment is unreasonable, discard this adaptive adjustment, and clear the cumulative number of times, the calculated average pressure and the average torque all to zero. After clearing, return and judge whether the adaptive activation conditions in Table 1 above are met

[0128] If the average pressure stored in the EEPROM is within a reasonable range, adjust the pressure corresponding to the clutch bite point (BP). First, according to the average torque stored in the EEPROM and the torque model, obtain the target pressure Pres_Current of the torque model corresponding to the average torque , then calculate the difference between the average pressure stored in the EEPROM and the target pressure Pres_Current of the torque model corresponding to the average torque , and use this difference as the compensation value for the pressure adjustment of the clutch bite point. And make corresponding restrictions on the step size of a single adaptive adjustment, limit the maximum step size that can be adjusted for each adaptive adjustment of the clutch bite point, and store the pressure of the clutch bite point adjusted according to the compensation value in the corresponding EEPROM. Finally, clear the cumulative number of times, the calculated average pressure and the average torque all to zero, return and judge whether the adaptive activation conditions in Table 1 above are met, and re-accumulate for adaptive adjustment

[0129] Although the present invention has been illustrated and described by referring to some preferred embodiments of the present invention, those of ordinary skill in the art should understand that the above content is a further detailed description of the present invention in combination with specific embodiments, and it cannot be determined that the specific implementation of the present invention is limited only to these descriptions. Those skilled in the art can make various changes in form and details, including making several simple deductions or substitutions, without departing from the spirit and scope of the present invention

Claims

1. An adaptive method for the clutch engagement point, characterized in that A dual-clutch transmission system applicable to an automobile, the dual-clutch transmission system comprising a dual-clutch gearbox, an engine, and a clutch; Wherein The clutch is arranged between the dual-clutch gearbox and the engine to cut off or connect the power transmission between the dual-clutch gearbox and the engine; The adaptive method for the clutch engagement point comprises the following steps: S1: Obtain the status information of the dual-clutch transmission system and the driving information of the automobile, and determine whether both the status information of the dual-clutch transmission system and the driving information of the automobile meet the preset adaptive activation conditions; If so, execute step S2; If not, continue to determine whether both the status information of the dual-clutch transmission system and the driving information of the automobile meet the preset adaptive activation conditions; S2: Obtain multiple sets of the status information and the driving information that meet the adaptive activation conditions, and calculate the average pressure value of the actual pressure of the clutch corresponding to each set of the status information and the driving information, and the average torque value of the input torque of the dual-clutch gearbox; S3: Determine the engagement point pressure compensation value according to the average torque value, the preset torque model, and the average pressure value; S4: Compensate the actual pressure of the clutch corresponding to the clutch engagement point according to the engagement point pressure compensation value; S5: Repeat steps S1 to S4 until the actual pressure corresponding to the clutch engagement point reaches the preset conditions.

2. The adaptive method for the clutch engagement point according to claim 1, wherein, In step S1, the status information of the dual-clutch transmission system includes the control state of the clutch, the input torque of the dual-clutch gearbox, the temperature of the oil in the dual-clutch gearbox, the temperature of the coolant in the dual-clutch transmission system, the engine speed, the clutch speed, and the engine torque; The driving information of the automobile includes the current gear and the road surface gradient; And The preset adaptive activation conditions include: The range of the current gear is from the 3rd gear to the 7th gear; The control state of the clutch is the micro-slip friction control state; The range of the input torque of the dual-clutch gearbox is from 15 N·m to 30 N·m; The range of the temperature of the oil in the dual-clutch gearbox is from 50 °C to 120 °C; The range of the road surface gradient is from 0 to 6%; The range of the difference between the engine speed and the clutch speed is from 0 to 30 r / min, and lasts for more than 0.5 s within this speed range; The engine torque is stable; and The above conditions need to be met simultaneously.

3. The adaptive method for the clutch engagement point according to claim 1, characterized in that, Step S2 includes: Obtain at least 300 sets of the status information and the driving information that meet the adaptive activation conditions; Obtain the actual pressure of the clutch and the input torque of the dual-clutch gearbox corresponding to each set of the status information and the driving information that meet the adaptive activation conditions; Calculate the average pressure value of the actual pressure of the clutch corresponding to the state information and the driving information that meet the adaptive activation condition for each group, and calculate the average torque value of the input torque of the dual-clutch transmission corresponding to the state information and the driving information that meet the adaptive activation condition for each group.

4. The adaptive method for the clutch engagement point according to claim 3, characterized in that After the step S2, it further includes: S2’: Store the average pressure value and the average torque value into the read-only memory of the vehicle.

5. The adaptive method for the clutch engagement point according to claim 4, characterized in that, After the step S2’, it further includes: S2”: Judge whether both the average pressure value and the average torque value are within a preset reasonable range; If so, execute step S3; If not, clear all the state information and the driving information that meet the adaptive activation condition for multiple groups, clear the average pressure value and the average torque value stored in the read-only memory, and re-execute the steps S1 to S2”.

6. The adaptive method for the clutch engagement point according to claim 1, characterized in that The step S3 includes: S31: Obtain the target pressure of the torque model corresponding to the average torque value according to the average torque value and the preset torque model; S32: Calculate the pressure difference between the average pressure value and the target pressure, and use the pressure difference as the bite point pressure compensation value.

7. The adaptive method for the clutch engagement point according to claim 1, characterized in that, After the step S3, it further includes: S3’: Limit the adaptive step size according to the bite point pressure compensation value, the state information of the dual-clutch transmission system, and the driving information of the vehicle to obtain the maximum single adjustment step size.

8. The adaptive method for the clutch engagement point according to claim 7, characterized in that The step S4 further includes: Compensate the actual pressure of the clutch corresponding to the clutch bite point according to the bite point pressure compensation value and the maximum single adjustment step size to obtain the compensated pressure of the clutch; and After the step S4, it further includes: Store the compensated pressure into the read-only memory of the vehicle.

9. The adaptive method for the clutch engagement point according to claim 8, wherein The compensating the actual pressure of the clutch corresponding to the clutch bite point according to the bite point pressure compensation value and the maximum single adjustment step size includes: Judge whether the bite point pressure compensation value is greater than the maximum single adjustment step size; If so, compensate the actual pressure of the clutch bite point according to the maximum single adjustment step size; If not, compensate the actual pressure of the clutch bite point according to the bite point pressure compensation value.

10. The adaptive method for the clutch engagement point as described in claim 8, characterized in that, The step S5 includes: Clear all the state information, the driving information, the average pressure value, and the average torque value that meet the adaptive activation condition in the previous adaptive cycle; Repeat the steps S1 to S4 to compensate the compensated pressure of the clutch obtained in the previous adaptive cycle until the actual pressure corresponding to the clutch bite point reaches a preset condition; and The preset condition includes: The target pressure of the preset torque model corresponding to the average torque value is equal to the average pressure value.

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