Hydraulic control wet clutch semi-coupling point self-learning method

Abstract

The application discloses a kind of liquid control wet clutch half combination point self-learning methods, and learning process includes the following processes: clutch emptying: clutch pressure oil way emptying is realized by controlling liquid control system solenoid valve current;Threshold self-learning: by setting learning pressure interval, drive solenoid valve current step, to obtain the threshold of half combination point self-learning pressure change rate;Half combination point pressure self-learning: based on threshold self-learning result, realize the automatic acquisition of clutch half combination point pressure;Result output: according to half combination point pressure self-learning result and temperature characteristic output wet clutch half combination point result.The method of the application is simple and easy to operate, and can be used for product initial and durability process and different use environment.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of hydraulic control wet clutch control in transmission system, and particularly relates to a hydraulic control wet clutch half engagement point self-learning method. BACKGROUND

[0002] The hydraulic control wet clutch is widely applied in the field of transmission technology, especially in the field of automatic transmission of automobiles, traditional AT, CVT, DCT, hybrid and new energy transmission, and the accurate control of the wet clutch has a decisive influence on the performance, durability and reliability of the whole machine, and the accurate acquisition of the half engagement point is one of the key technologies.

[0003] In the initial state of the wet clutch, due to the influence of the engineering tolerance of the related parts of the product, the half engagement point of the clutch assembly is often distributed with a dispersion error; in the actual application, the half engagement point pressure of the wet clutch measured by the sensor at the position is not the same due to the change of the environmental oil temperature or the different oil products; in addition, during the service life, the half engagement point of the clutch will change with the use mileage due to the wear of the clutch. Therefore, the accurate acquisition of the self-learning method of the half engagement point of the hydraulic control wet clutch has been the research focus and hotspot in the field of wet clutch control. SUMMARY

[0004] The application provides a hydraulic control wet clutch half engagement point self-learning method, and the method has the advantages of simplicity and practicability, and can be used in the initial stage and the durability use process of the product and different use environments.

[0005] The technical scheme for solving the above problems is as follows:

[0006] The hydraulic control wet clutch half engagement point self-learning method includes the following processes in the learning process:

[0007] Clutch emptying: the clutch pressure oil way is emptied by controlling the current of the electromagnetic valve of the hydraulic control system;

[0008] Threshold self-learning: the threshold value of the self-learning pressure change rate of the half engagement point is obtained by setting the learning pressure interval and the driving electromagnetic valve current step;

[0009] Half engagement point pressure self-learning: based on the threshold self-learning result, the half engagement point pressure of the clutch is automatically acquired;

[0010] Result output: the half engagement point result of the wet clutch is output according to the half engagement point pressure self-learning result and the temperature characteristic.

[0011] Further, the process of the clutch emptying is as follows:

[0012] Control the solenoid valve current with a first current slope a 1 Increase the clutch pressure from 0 current to a maximum pressure P1 with a first current slope a 1 The maximum pressure P1 is a calibration value, the first current slope is set by calibration a 1 To achieve the optimization of clutch emptying time, the maximum pressure P1 is set by calibration to achieve effective emptying of different engineering tolerance clutch samples, in addition, the above process also records the correspondence between clutch pressure and solenoid valve current.

[0013] Further, the threshold self-learning process is as follows:

[0014] Control the solenoid valve current to a first current value I 1 And maintain for N seconds, then with a second current slope a 2 Increase the solenoid valve current to a second current value I 2, record the actual clutch pressure, and filter the actual clutch pressure, and calculate the pressure change rate of the filtered clutch pressure simultaneously, take the maximum value of the pressure change rate in the preset pressure range (P3, P4) as the threshold self-learning result output;

[0015] P3, P4 are respectively the lower limit and upper limit calibration values of the threshold acquisition range.

[0016] Further, the second current slope a 2 is a calibration value.

[0017] Further, the first current value I 1 is the current value corresponding to the minimum pressure P2 in the correspondence between clutch pressure and solenoid valve current during the emptying process;

[0018] The second current value I 2 is the current value corresponding to the maximum pressure P1 in the correspondence between clutch pressure and solenoid valve current during the emptying process.

[0019] Further, the threshold self-learning is performed twice, and the fluctuation amount of the two learning results is calculated and compared with the preset fluctuation amount, if it is less than the preset fluctuation amount, the learning is successful, and the average of the two times is output; if it is greater than the preset fluctuation amount, the learning is unsuccessful.

[0020] Further, the process of half-clutch-point pressure self-learning is as follows:

[0021] Control the solenoid valve current from a first current value I 1 And maintain for M seconds, then with a second current slope a2 increase, record the clutch actual pressure, and filter the clutch actual pressure, simultaneously calculate the pressure change rate of the filtered clutch pressure, simultaneously compare the result with the threshold value self-learning output, when the clutch pressure change rate is greater than or equal to the threshold value, end, record the filtered clutch pressure at this time as the output of one half combination point pressure self-learning result, request the electromagnetic valve current to be 0; otherwise, continue to increase the electromagnetic valve current.

[0022] Further, the half combination point pressure self-learning is repeated multiple times, and multiple half combination point pressure learning results are output.

[0023] Further, the maximum fluctuation of the pressure results of multiple half combination point pressure self-learnings is calculated, and compared with a preset fluctuation threshold value, if the maximum fluctuation of the half combination point pressure self-learnings is greater than the preset threshold value, it is judged that the learning fails, if the maximum fluctuation of the half combination point pressure self-learnings is less than the preset threshold value, it is judged that the learning succeeds, and the average value of multiple half combination point pressure self-learnings is output, then according to the current half combination point pressure self-learning oil temperature and the preset temperature compensation calibration table, the temperature compensation value is obtained, and the average value is added to the output, and the final wet clutch half combination point is output.

[0024] The application is suitable for wet clutch single body off-line detection, transmission assembly or whole vehicle off-line equipped with wet clutch, and self-learning of clutch half combination point in the whole vehicle use process. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The flow chart of the liquid-controlled wet clutch half combination point self-learning method of the application.

[0026] Figure 2 The curve schematic diagram of the half combination point self-learning example process. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the application clearer, the technical scheme in the embodiments of the application is described in more detail in combination with the drawings in the embodiments of the application. The described embodiments are part of the embodiments of the application, rather than all the embodiments of the application. The embodiments described by reference to the drawings are exemplary, and are intended to explain the application, and cannot be simply understood as the limitation of the application. Based on the embodiments of the application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the application.

[0028] The application is described in detail below in combination with the drawings.

[0029] As Figure 1 and Figure 2As shown, the self-learning method of the hydraulic control wet clutch half-engagement point of the application includes four processes: clutch emptying, threshold self-learning, half-engagement point pressure self-learning, and result output. Each process and the relationship between them will be described below:

[0030] Clutch emptying: The clutch pressure oil passage is emptied by controlling the electromagnetic valve current of the hydraulic control system. In this embodiment, the specific process of the clutch emptying is as follows:

[0031] The current of the hydraulic control electromagnetic valve is controlled according to the first current slope a 1The clutch pressure is increased from 0 current to the maximum pressure P1, where the first current slope a 1The maximum pressure P1 is a calibrated quantity, and the first current slope is set through calibration a 1to optimize the clutch emptying time, and the maximum pressure P1 is set through calibration to effectively empty different engineering tolerance clutch samples. In addition, the above process also records the corresponding relationship between the clutch pressure and the electromagnetic valve current.

[0032] Threshold self-learning: The threshold value of the half-engagement point self-learning pressure change rate is obtained by setting the learning pressure interval and the driving electromagnetic valve current step. In this embodiment, the specific process of the threshold self-learning is as follows:

[0033] The electromagnetic valve current is controlled to be the first current value I 1and maintained for N seconds, where the value of N is preferably 1, and then the electromagnetic valve current is increased to the second current value a 2with the second current slope I 2The actual clutch pressure is recorded, and the actual clutch pressure is filtered. The filtered clutch pressure is calculated for the pressure change rate. The maximum value of the pressure change rate in the preset pressure interval (P3, P4) is taken as the threshold self-learning result output. Wherein:

[0034] P3 and P4 are respectively the lower and upper limit calibration quantities of the threshold acquisition interval.

[0035] The second current slope a 2is a calibrated quantity.

[0036] The first current value I 1is the current value corresponding to the minimum pressure P2 in the corresponding relationship between the clutch pressure and the electromagnetic valve current in the emptying process.

[0037] The second current value I 2is the current value corresponding to the maximum pressure P1 in the corresponding relationship between the clutch pressure and the electromagnetic valve current in the emptying process.

[0038] The threshold self-learning is performed twice, and the fluctuation of the two learning results is calculated and compared with the preset fluctuation. If the fluctuation is less than the preset fluctuation, the learning is successful, and the average of the two results is output. If the fluctuation is greater than the preset fluctuation, the learning is unsuccessful.

[0039] Half-engagement point pressure self-learning: based on the threshold self-learning result, the automatic acquisition of the clutch half-engagement point pressure is realized. In this embodiment, the specific process of the half-engagement point pressure self-learning is as follows:

[0040] The control solenoid current is increased from the first current value I 1 and maintained for M seconds, and the value of M is preferably 1, and then the second current slope a 2 is increased, the actual clutch pressure is recorded, and the actual clutch pressure is filtered, the filtered clutch pressure is calculated, and the result output by the threshold self-learning is compared. When the pressure change rate of the filtered clutch pressure is greater than or equal to the threshold value, the process is ended, the filtered clutch pressure at this time is recorded as an output half-engagement point pressure self-learning result, and the solenoid current is requested to be 0. Otherwise, the solenoid current continues to be increased.

[0041] The half-engagement point pressure self-learning is repeated multiple times, and multiple half-engagement point pressure learning results are output. In this embodiment, the number of times of repeating the half-engagement point pressure self-learning is preferably 5. Other cycle times can also be set according to application requirements.

[0042] Result output: according to the half-engagement point pressure self-learning result and the temperature characteristic, the half-engagement point result of the wet clutch is output. The maximum fluctuation of the pressure results of multiple half-engagement point pressure self-learnings is calculated, and compared with the preset fluctuation threshold. If the maximum fluctuation of the half-engagement point pressure self-learning is greater than the preset threshold, it is judged that the learning is unsuccessful. If the maximum fluctuation of the half-engagement point pressure self-learning is less than the preset threshold, it is judged that the learning is successful, and the average of multiple half-engagement point pressure self-learnings is output. Then, according to the oil temperature of the current half-engagement point pressure self-learning and the preset temperature compensation calibration table, the temperature compensation value is obtained, which is added to the output average value, and the final wet clutch half-engagement point of the self-learning is output.

[0043] The hydraulic control wet clutch half-engagement point self-learning is completed.

Claims

1. A method for self-learning of a semi-coupling point of a fluid-controlled wet clutch, characterized in that, The learning process comprises the following processes: Clutch emptying: the clutch pressure oil channel is emptied by controlling the solenoid valve current of the hydraulic control system; the process of the clutch emptying is as follows: Controlling the solenoid valve current with a first current ramp a 1. The clutch pressure is increased from 0 current to a maximum pressure P1 with a first current ramp a 1. The maximum pressure P1 is a calibrated value and the first current ramp is set by calibration a 1. To achieve an optimized clutch evacuation time, the maximum pressure P1 is set by calibration to achieve an effective evacuation of different engineering tolerance clutch samples, in addition, the above process also records the corresponding relationship between the clutch pressure and the solenoid valve current; Threshold self-learning: the threshold value of the self-learning pressure change rate of the half engagement point is obtained by setting the learning pressure interval and the driving solenoid valve current step; the process of the threshold self-learning is as follows: Control the solenoid valve current to the first current value I 1 and maintain for N seconds, then at the second current slope a 2. Increase the current of the solenoid valve to the second current value. I 2. Record the actual clutch pressure and filter the actual clutch pressure. Simultaneously calculate the pressure change rate of the filtered clutch pressure. Take the maximum value of the pressure change rate in the preset pressure range (P3, P4) as the threshold self-learning result output. P3 and P4 are respectively the lower limit and upper limit calibration values of the threshold value acquisition interval; Half engagement point pressure self-learning: based on the threshold self-learning result, the automatic acquisition of the clutch half engagement point pressure is realized; the process of the half engagement point pressure self-learning is as follows: controlling the solenoid valve current from a first current value I 1and maintaining M seconds, then increasing the solenoid valve current at a second current ramp a 2, recording the actual clutch pressure, filtering the actual clutch pressure, calculating the pressure rate of change of the filtered clutch pressure, comparing the result with the threshold value self-learning output, ending when the clutch pressure rate of change is greater than or equal to the threshold value, recording the filtered clutch pressure at this time as the output of one half of the self-learning result of the clutch pressure, requesting the solenoid valve current to be 0; otherwise, continue to increase the solenoid valve current; Result output: according to the half engagement point pressure self-learning result and the temperature characteristic, the half engagement point result of the wet clutch is output; the maximum fluctuation of the pressure result of the multiple half engagement point pressure self-learning is calculated, and is compared with the preset fluctuation threshold value; if the maximum fluctuation of the half engagement point pressure self-learning is greater than the preset threshold value, it is judged that the learning fails; if the maximum fluctuation of the half engagement point pressure self-learning is less than the preset threshold value, it is judged that the learning succeeds, and the average value of the multiple half engagement point pressure self-learning is output; then, according to the current half engagement point pressure self-learning oil temperature and the preset temperature compensation calibration table, the temperature compensation value is obtained, is added to the output average value, and the final half engagement point of the wet clutch is output.

2. The fluid-controlled wet-type clutch half-engagement point self-learning method according to claim 1, characterized by, Second current slope a 2 is a nominal quantity.

3. The fluid-controlled wet clutch half-engagement point self-learning method according to claim 1, characterized in that, first current value I 1 is the current value corresponding to the minimum pressure P2 in the correspondence between the clutch pressure and the solenoid current in the emptying process Second current value I 2 is the current value corresponding to the maximum pressure P1 in the correspondence between the clutch pressure during the emptying process and the solenoid current.

4. The fluid-controlled wet clutch half-engagement point self-learning method according to claim 1, characterized in that, The threshold self-learning is performed twice, the fluctuation of the learning results of the two times is calculated, and is compared with the preset fluctuation; if the fluctuation is less than the preset fluctuation, the learning succeeds, and the average value of the two times is output; if the fluctuation is greater than the preset fluctuation, the learning fails.

5. The fluid-controlled wet-clutch half-engagement-point self-learning method according to claim 1, characterized by The half engagement point pressure self-learning is repeated multiple times, and the half engagement point pressure learning results of the multiple times are output.

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