Clutch control method

Abstract

The present invention provides a clutch control method, including: determining whether the clutch enters a static shifting condition, if it enters the static shifting condition, then determining whether the clutch activates an adaptive program according to an activation condition, if it is determined that the clutch activates the adaptive program, then entering an adaptive program execution step; monitoring whether a shifting shock exceeding a preset threshold occurs during the process of the clutch completing locking, obtaining the stage at which the shifting shock occurs in the static shifting condition, if the shifting shock exceeds the preset threshold, then obtaining adjustment parameters for adjusting the hydraulic characteristic curve of the clutch according to the stage, and entering a hydraulic characteristic curve adjustment step; adjusting the hydraulic characteristic curve according to the adjustment parameters. The shifting shock under the static shifting condition is identified through the adaptive program, and the hydraulic characteristic curve of the clutch is adaptively corrected according to the identified shifting shock, so as to alleviate the problem of static shifting shock and improve the comfort of static shifting.

Description

Technical Field

[0001] The present invention relates to the field of automobiles, and specifically to a clutch control method. Background Art

[0002] A continuously variable transmission (CVT) is an automatic transmission that can continuously change the transmission ratio within a certain range by changing the working radii of two pulleys.

[0003] Generally, a CVT realizes the switching between the forward gear (Drive), reverse gear (Reverse), and neutral gear (Neutral) through a planetary gear mechanism, a D - range clutch, and an R - range clutch. After the driver switches the gear to the D - range or R - range, the transmission control unit (TCM) calculates the clutch control pressure, and then calculates the control current of the clutch solenoid valve through the hydraulic characteristic curve (pressure - current characteristic) of the clutch, so that the clutch is engaged. If the deviation of the hydraulic characteristic curve of the clutch is large, it will cause a large deviation between the actual pressure in the clutch cylinder and the control pressure output by the TCM, which usually manifests as a static shift shock on the vehicle. Since there is usually no pressure sensor in the cylinders of the D - range and R - range clutches of the CVT, the deviation between the actual pressure and the control pressure of the clutch can only be judged indirectly.

[0004] The clutch control process in the static shift condition is divided into a pre - charge stage, an oil pressure stabilization stage, and an oil pressure rising stage in chronological order. Among them, the clutch pressure in the oil pressure stabilization stage is maintained at a level just enough to make the clutch transmit torque. The purpose is to eliminate the clearance of the driveline with a small torque in this stage and avoid the excessive speed of the transmission components at the moment when the clearance is eliminated, resulting in a static shift shock.

[0005] Both too high or too low actual pressure in the oil pressure stabilization stage will cause the problem of static shift shock:

[0006] 1. When the actual pressure in the oil pressure stabilization stage is too low, the clutch cannot transmit torque in this stage. Since the clearance of the driveline is not eliminated in the oil pressure stabilization stage, the static shift shock will appear in the subsequent oil pressure rising stage.

[0007] 2. When the actual pressure in the oil pressure stabilization stage is too high, the torque transmitted by the clutch in the oil pressure stabilization stage is too large, making the rotational speed of the transmission components before the clearance of the driveline too high, resulting in an obvious shock at the moment when the clearance of the driveline is eliminated. Summary of the Invention

[0008] To solve the above technical problems, the object of the present invention is to provide a clutch control method. Aiming at the problem of the static shift shock of the whole vehicle caused by the actual pressure deviation of the clutch, an adaptive program is used to identify the shift shock under the static shift condition caused by the actual pressure deviation, and the hydraulic characteristic curve of the clutch is adaptively corrected according to the identified shift shock, so that the clutch control program in the transmission control unit can adapt to the differences in the hydraulic characteristic curves of the clutch and the changes in the hydraulic characteristic curves during the life cycle, alleviate the problem of static shift shock caused by the differences in the hydraulic characteristic curves of the clutch, and improve the comfort of static shifting.

[0009] The clutch control method provided by the present invention includes: an adaptive program activation step, determining whether the clutch enters the static shift condition. If it enters the static shift condition, it is determined whether the clutch activates the adaptive program according to the activation condition. If it is determined that the clutch activates the adaptive program, it enters the adaptive program execution step; if it does not enter the static shift condition, the adaptive program activation step ends; the adaptive program execution step, monitoring whether there is a shift shock exceeding the preset threshold during the process of the clutch completing locking, obtaining the stage at which the shift shock appears in the static shift condition. If the shift shock exceeds the preset threshold, the adjustment parameters for adjusting the hydraulic characteristic curve of the clutch are obtained according to the stage, and it enters the hydraulic characteristic curve adjustment step; if the shift shock does not exceed the preset threshold, the adaptive program execution step ends; the hydraulic characteristic curve adjustment step, adjusting the hydraulic characteristic curve according to the adjustment parameters.

[0010] With the above solution, when the driver actually shifts the gear lever position from the parking gear or neutral gear to the forward gear or reverse gear, etc., during the gear shift from the stationary state of the vehicle, aiming at the problem of the static shift shock of the whole vehicle caused by the actual pressure deviation of the clutch, it is determined whether the clutch enters the static shift condition according to the deviation between the actual pressure and the control pressure of the clutch. Then it is determined whether the clutch activates the adaptive program according to the activation condition. After the adaptive program is activated, wait for the clutch to complete locking. During this period, monitor whether there is a large shift shock during the process of the clutch completing locking. Then the hydraulic characteristic curve of the clutch is corrected according to the identified shift shock, so that the clutch control program in the transmission control unit (TCM) can adapt to the differences in the hydraulic characteristic curves of the clutch and the changes in the hydraulic characteristic curves during the life cycle. Furthermore, the clutch hydraulic characteristic adaptive strategy enables the clutch control program in the transmission control unit to adapt to the deviations of different clutch hydraulic characteristic curves and the changes in the hydraulic characteristic curves during the clutch life cycle, alleviate the problem of static shift shock caused by the differences in the hydraulic characteristic curves of the clutch, and improve the comfort of static shifting. In addition, the method of indirectly judging whether the actual pressure of the clutch is too high or too low by using the degree of static shift shock in this embodiment can realize the adaptive correction of the deviation of the hydraulic characteristic curve without installing a pressure sensor.

[0011] According to another specific embodiment of the present invention, a clutch control method disclosed by the embodiment of the present invention, the hydraulic characteristic curve adjustment step includes: reading the current hydraulic characteristic curve of the clutch from the memory, and adjusting the current hydraulic characteristic curve according to the adjustment parameter to obtain a new hydraulic characteristic curve. If the new hydraulic characteristic curve does not exceed the theoretical threshold of the hydraulic characteristic curve, the new hydraulic characteristic curve is updated to the memory; if the new hydraulic characteristic curve exceeds the theoretical threshold of the hydraulic characteristic curve, the new hydraulic characteristic curve is not updated to the memory.

[0012] By adopting the above scheme, the rationality of the new hydraulic characteristic curve can be judged, and then it is ensured that the updated new hydraulic characteristic curve is reasonable, avoiding the influence of the coverage of wrong values on the normal shifting of the clutch.

[0013] According to another specific embodiment of the present invention, a clutch control method disclosed by the embodiment of the present invention, in the adaptive program activation step, the activation conditions include that the throttle is less than a preset throttle threshold, the braking pressure is greater than a preset braking pressure threshold, the vehicle speed is less than a preset vehicle speed threshold, the engine speed is less than a preset engine speed threshold, and the clutch has no current fault.

[0014] By adopting the above scheme, it is possible to accurately select when to start the adaptive program.

[0015] According to another specific embodiment of the present invention, a clutch control method disclosed by the embodiment of the present invention, in the adaptive program activation step, if any moment during the process of the clutch completing the locking process does not meet the activation conditions, the adaptive program is terminated. If all moments during the process of the clutch completing the locking process meet the activation conditions, the stage where the shift shock occurs is recorded.

[0016] By adopting the above scheme, the stability and rationality of the stage where the shock occurs can be recorded, avoiding the influence of individual fluctuations on the judgment of the activation of the adaptive program.

[0017] According to another specific embodiment of the present invention, a clutch control method disclosed by the embodiment of the present invention, in the adaptive program execution step, the basis for monitoring the shift shock is the rotational speed of the driven end of the clutch. And monitor the rotational speed of the driven end of the clutch during the process of the clutch completing the locking; if the maximum value of the rotational speed of the driven end of the clutch is greater than or equal to the hydraulic characteristic curve adjustment threshold, the shift shock exceeds the preset threshold, record the clutch control stage at the time when the maximum value of the rotational speed of the driven end of the clutch appears, and obtain the adjustment parameter; if the maximum value of the rotational speed of the driven end of the clutch is less than the hydraulic characteristic curve adjustment threshold, the adaptive program ends. The degree of static shift shock during the clutch engagement process is related to the rotational speed of the driven end of the clutch, so the highest rotational speed of the driven end of the clutch during the static shift is used to characterize the magnitude of the static shift shock.

[0018] With the above - mentioned solution, it is determined whether an obvious static shift shock occurs by monitoring whether the maximum rotational speed of the clutch driven end is greater than or equal to the hydraulic characteristic curve adjustment threshold. If it is greater than or equal to the hydraulic characteristic curve adjustment threshold, it indicates that an obvious static shift shock has occurred. At this time, adaptive adjustment is carried out, thus avoiding the shock caused by small - range fluctuations, preventing unnecessary activation of the adaptive program, and improving the reliability of the adjustment.

[0019] According to another specific embodiment of the present invention, a clutch control method disclosed by the embodiment of the present invention, the clutch control stage is the chronological order of the clutch control process in the static shift working condition, and the clutch control stage includes a pre - charge stage, an oil pressure stabilization stage, and an oil pressure rising stage.

[0020] With the above - mentioned solution, control can be carried out more reliably and conveniently.

[0021] According to another specific embodiment of the present invention, a clutch control method disclosed by the embodiment of the present invention, the adjustment parameters include the adjustment amplitude and the adjustment direction of the hydraulic characteristic curve.

[0022] Furthermore, the adjustment amplitude is obtained by looking up a table according to the maximum rotational speed of the clutch driven end.

[0023] Furthermore, obtain the stage in which the maximum rotational speed of the clutch driven end appears in the static shift working condition, and compare the relative positions of the actual clutch pressure and the clutch control pressure in the stage to obtain the adjustment direction.

[0024] With the above - mentioned solution, the method of indirectly judging whether the actual clutch pressure is too high or too low by the degree of static shift shock can realize the adaptive correction of the deviation of the hydraulic characteristic curve without installing a pressure sensor, and the clutch hydraulic characteristic adaptive strategy enables the clutch control program in the transmission control unit to adapt to the deviation of different clutch hydraulic characteristic curves and the change of the hydraulic characteristic curve during the clutch life cycle.

[0025] According to another specific embodiment of the present invention, a clutch control method disclosed by the embodiment of the present invention, in the adaptive program activation step, if a static shift action is executed, the clutch enters the static shift working condition.

[0026] The beneficial effects of the present invention are:

[0027] When the actual driver of a vehicle switches the shift lever position from the park or neutral position to the forward or reverse gear, etc., during the gear shift from the vehicle's stationary state, to address the problem of static shift shock in the whole vehicle caused by the deviation of the actual clutch pressure, it is determined whether the clutch enters the static shift working condition based on the deviation between the actual clutch pressure and the control pressure. Then, it is determined whether to activate the adaptive program for the clutch based on the activation conditions. After the adaptive program is activated, wait for the clutch to complete locking, and monitor whether a large shift shock occurs during the process of the clutch completing locking. Then, the clutch hydraulic characteristic curve is corrected according to the identified shift shock, so that the clutch control program in the transmission control unit (TCM) can adapt to the differences in the clutch hydraulic characteristic curves and the changes in the hydraulic characteristic curves during the life cycle. Furthermore, the clutch hydraulic characteristic adaptive strategy enables the clutch control program in the transmission control unit to adapt to the deviations of different clutch hydraulic characteristic curves, as well as the changes in the hydraulic characteristic curves during the clutch life cycle, and alleviates the problem of static shift shock caused by the differences in the clutch hydraulic characteristic curves, improving the comfort of static shifting. In addition, the method of indirectly judging whether the actual clutch pressure is too high or too low by using the degree of static shift shock in this embodiment can achieve the adaptive correction of the deviation of the hydraulic characteristic curve without installing a pressure sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a flow block diagram of a clutch control method provided in an embodiment of the present invention;

[0029] Figure 2 is a schematic diagram of adaptive adjustment search for a clutch control method provided in an embodiment of the present invention;

[0030] Figure 3 is a flow block diagram of a clutch control method provided in an embodiment of the present invention;

[0031] Figure 4 is a flow block diagram of a clutch control method provided in an embodiment of the present invention;

[0032] Figure 5 is a schematic diagram of the clutch engagement process of a clutch control method provided in an embodiment of the present invention;

[0033] Figure 6 is a schematic diagram of the clutch engagement process of a clutch control method provided in an embodiment of the present invention;

[0034] Figure 7 is a schematic diagram of adaptive adjustment of the clutch hydraulic characteristic curve of a clutch control method provided in an embodiment of the present invention;

[0035] Figure 8Schematic diagram of adaptive adjustment of clutch hydraulic characteristic curve provided in the embodiment of the present invention. Detailed implementation mode

[0036] The following specific embodiments illustrate the implementation mode 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 preferred embodiments, this does not mean that the features of this invention are limited to this implementation mode. On the contrary, the purpose of introducing the invention in conjunction with the implementation mode is to cover other alternatives or modifications that may extend 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 using 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 in the present invention and the features in the embodiments can be combined with each other.

[0037] It should be noted that in this specification, similar reference numerals and letters indicate 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.

[0038] In the description of this embodiment, it should be noted that the orientation or positional relationship indicated by terms such as "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 invention product is usually 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 cannot be understood as a limitation to the present invention.

[0039] Terms such as "first" and "second" are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0040] In the description of this embodiment, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "connected", and "connected" 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 situations.

[0041] To make the purpose, technical solution, and advantages of the present invention clearer, the implementation mode of the present invention will be further described in detail below with reference to the drawings.

[0042] Embodiment

[0043] This embodiment provides a clutch control method, as Figure 1 shown, including: an adaptive program activation step, an adaptive program execution step, and a hydraulic characteristic curve adjustment step.

[0044] Among them, in the adaptive program activation step, it is judged whether the clutch enters the static shift condition. If it enters the static shift condition, it is judged whether to activate the adaptive program according to the activation condition. If it is judged that the clutch activates the adaptive program, it enters the adaptive program execution step; if it does not enter the static shift condition, the adaptive program activation step ends. In the adaptive program execution step, it is monitored whether there is a shift shock exceeding a preset threshold during the process of the clutch completing locking, and the stage at which the shift shock appears in the static shift condition is obtained. If the shift shock exceeds the preset threshold, adjustment parameters for adjusting the hydraulic characteristic curve of the clutch are obtained according to the stage, and it enters the hydraulic characteristic curve adjustment step; if the shift shock does not exceed the preset threshold, the adaptive program execution step ends. In the hydraulic characteristic curve adjustment step, the hydraulic characteristic curve is adjusted according to the adjustment parameters.

[0045] Specifically, the static shift shock is caused by the deviation between the actual pressure and the control pressure of the clutch. However, pressure sensors are usually not equipped in the cylinders of the clutches in D gear and R gear, and it is impossible to directly judge the deviation between the actual pressure and the control pressure of the clutch. This embodiment uses the method of indirectly judging whether the actual pressure of the clutch is too high or too low by the degree of static shift shock, and can realize the adaptive correction of the deviation of the hydraulic characteristic curve without installing a pressure sensor.

[0046] According to the shift shock exceeding the preset threshold, obtaining the stage at which the shift shock appears in the static shift condition means obtaining the stage at which the shift shock occurs and the degree of the shift shock. The stage at which the shift shock appears in the static shift condition refers to that the clutch control process in the static shift condition is divided into a pre-charging stage, an oil pressure stabilization stage, and an oil pressure rising stage in chronological order. Those skilled in the art can monitor the stage where the shift shock appears in the static shift condition by time, or directly judge the stage in the static shift condition according to the oil pressure.

[0047] To better understand obtaining the adjustment parameters for adjusting the hydraulic characteristic curve of the clutch according to the stage, take the example where the static shift shock appears in the subsequent oil pressure rising stage. When the actual pressure in the oil pressure stabilization stage is too low, the clutch cannot transmit torque in this stage. Since the driveline clearance cannot be eliminated in the oil pressure stabilization stage, the static shift shock will appear in the subsequent oil pressure rising stage. Conversely, according to the static shift shock appearing in the oil pressure rising stage, the adjustment parameters can be obtained.

[0048] Regarding the preset threshold for shift shock, those skilled in the art can select and set it as a static value according to the actual requirements of different vehicle models, empirical values, and the level of manufacturing technology. The preset threshold for shift shock can also be a dynamic value that is dynamically optimized. For example, Figure 2 as shown, it is continuously optimized on the basis of adaptively optimizing by adjusting the hydraulic characteristic curve of the parameters to reach the theoretical minimum value, and then continuously reducing the difference in the clutch hydraulic characteristic curve in the direction of adaptive optimization.

[0049] It should be understood that Figure 2 is a search graph for adaptive program adjustment, where the ordinate is the adaptive value of shift shock and the abscissa is the number of optimization adjustments. After determining the adjustment parameters, the adaptive program adjustment search can be carried out as Figure 2 shown. For example, after determining the amplitude and direction of the adjustment parameters, the amount to be adjusted each time can be searched again within the found adjustment direction and amplitude range through the Figure 2 adjustment search process to avoid the adverse effects caused by parameter mutations. Figure 2 In it, the Kth adjustment of the hydraulic characteristic curve is used as the boundary to divide into a rough adjustment area and a fine adjustment area. In the rough adjustment area, the span of adjusting the shift shock value is relatively large compared to the fine adjustment area. After multiple adjustments in the rough adjustment area, the average value and the minimum value of the shift shock for K - 1 shifts are obtained, and then the adjustment slope is obtained based on the average value and the minimum value of the shift shock, which is used as the direction of adaptive optimization. Furthermore, the minimum value of the shift shock is obtained in the K + nth adaptive adjustment. Finally, it is judged whether it has fallen into the local optimal value according to whether the change in adjusting the shift shock no longer has an obvious effect, and then the above process is repeated to adjust the optimization direction.

[0050] Regarding the hydraulic characteristic curve, the hydraulic characteristic curve, that is, the pressure - current characteristic curve, can read the current clutch hydraulic characteristic curve from the electrically erasable programmable read - only memory (EEPROM), and then adjust the current hydraulic characteristic curve.

[0051] The clutch control method provided in this embodiment can be used for the control strategy of continuously variable transmissions, and can also be used for the control strategies of other transmissions equipped with torque converters, such as hydraulic mechanical automatic transmissions, to alleviate the static shift shock problem caused by the difference in the clutch hydraulic characteristic curve.

[0052] With the above solution, when the actual driver of the vehicle switches the position of the shift lever from the park or neutral gear to the forward or reverse gear, etc., that is, when shifting gears during vehicle stationary, for the problem of the static shift shock of the whole vehicle caused by the actual pressure deviation of the clutch, it is determined whether the clutch enters the static shift working condition according to the deviation between the actual pressure and the control pressure of the clutch. Then, it is determined whether the adaptive program of the clutch is activated according to the activation condition. After the adaptive program is activated, wait for the clutch to complete locking, and monitor whether there is a large shift shock during the process of the clutch completing locking. Then, the hydraulic characteristic curve of the clutch is corrected according to the stage and degree of the identified shift shock, so that the clutch control program in the transmission control unit (TCM) can adapt to the differences in the hydraulic characteristic curves of the clutch and the changes in the hydraulic characteristic curves during the life cycle. Furthermore, the clutch hydraulic characteristic adaptive strategy enables the clutch control program in the transmission control unit to adapt to the deviations of different clutch hydraulic characteristic curves, as well as the changes in the hydraulic characteristic curves during the clutch life cycle, alleviates the problem of static shift shock caused by the differences in the clutch hydraulic characteristic curves, and improves the comfort of static shifting. In addition, the method of indirectly judging whether the actual pressure of the clutch is too high or too low by using the degree of static shift shock in this embodiment can realize the adaptive correction of the deviation of the hydraulic characteristic curve without installing a pressure sensor.

[0053] According to another specific embodiment of the present invention, a clutch control method disclosed in the embodiment of the present invention is as Figure 3 shown. The hydraulic characteristic curve adjustment step includes: reading the current hydraulic characteristic curve of the clutch from the memory, and adjusting the current hydraulic characteristic curve according to the adjustment parameters to obtain a new hydraulic characteristic curve. If the new hydraulic characteristic curve does not exceed the theoretical threshold of the hydraulic characteristic curve, update the new hydraulic characteristic curve to the memory; if the new hydraulic characteristic curve exceeds the theoretical threshold of the hydraulic characteristic curve, do not update the new hydraulic characteristic curve to the memory.

[0054] Specifically, the memory can be an electrically erasable programmable read-only memory (EEPROM), and the theoretical threshold of the hydraulic characteristic curve can calculate the possible deviation or tolerance according to the data parameters. The specific acceptable range of the deviation or tolerance can be calculated according to the manufacturing process level or the specific vehicle model.

[0055] During operation, the current clutch hydraulic characteristic curve is read from the memory, and the hydraulic characteristic curve is adaptively corrected according to the adjustment parameters to calculate a new hydraulic characteristic curve. After obtaining the new hydraulic characteristic curve of the clutch, it is compared with the upper and lower limits of the theoretical threshold of the hydraulic characteristic curve. If the new hydraulic characteristic curve is within the upper and lower limits of the theoretical threshold, it indicates that the new hydraulic characteristic curve is within a reasonable range, and then the new hydraulic characteristic curve is used to replace the original hydraulic characteristic curve and stored in the memory; if the new hydraulic characteristic curve exceeds the upper and lower limits, the new hydraulic characteristic curve is not stored, and the clutch hydraulic characteristic adaptive program is ended.

[0056] By adopting the above solution, the rationality of the new hydraulic characteristic curve can be judged, and then it can be ensured that the updated new hydraulic characteristic curve is reasonable, avoiding the influence of the coverage of wrong values on the normal shifting of the clutch.

[0057] According to another specific embodiment of the present invention, a clutch control method disclosed in the embodiment of the present invention, in the adaptive program activation step, the activation conditions include that the throttle is less than a preset throttle threshold, the brake pressure is greater than a preset brake pressure threshold, the vehicle speed is less than a preset vehicle speed threshold, the engine speed is less than a preset engine speed threshold, and the clutch has no current fault.

[0058] By adopting the above solution, it is possible to accurately select when to start the adaptive program.

[0059] According to another specific embodiment of the present invention, a clutch control method disclosed in the embodiment of the present invention, in the adaptive program activation step, if any moment during the period when the clutch completes the locking process does not meet the activation conditions, the adaptive program is terminated. If all moments during the period when the clutch completes the locking process meet the activation conditions, the stage where the shift shock occurs is recorded.

[0060] By adopting the above solution, it can ensure the stability and rationality of the stage where the shock occurs, and avoid the influence of individual fluctuations on the judgment of the activation of the adaptive program.

[0061] According to another specific embodiment of the present invention, a clutch control method disclosed in the embodiment of the present invention, in the adaptive program execution step, such as Figure 2-3 and Figure 5-6As shown, the basis for monitoring the shift shock is the rotational speed of the clutch driven end. And monitor the rotational speed of the clutch driven end during the process of the clutch completing locking; if the maximum value of the rotational speed of the clutch driven end is greater than or equal to the hydraulic characteristic curve adjustment threshold, the shift shock exceeds the preset threshold, record the clutch control stage at the time when the maximum value of the rotational speed of the clutch driven end appears, and obtain the adjustment parameter; if the maximum value of the rotational speed of the clutch driven end is less than the hydraulic characteristic curve adjustment threshold, end the adaptive program. The degree of static shift shock during the clutch engagement process is related to the rotational speed of the clutch driven end, so the highest rotational speed of the clutch driven end during static shifting is used to characterize the magnitude of the static shift shock.

[0062] Specifically, when the actual pressure during the oil pressure stabilization stage is too high, the torque transmitted by the clutch during the oil pressure stabilization stage is too large, causing the rotational speed of the transmission components before the elimination of the transmission system clearance to be too high, resulting in an obvious shock at the moment of the elimination of the transmission system clearance. Therefore, the degree of static shift shock during the clutch engagement process is related to the rotational speed of the clutch driven end, and the highest rotational speed of the clutch driven end during static shifting can be used to characterize the magnitude of the static shift shock.

[0063] In this embodiment, in combination with the schematic diagram for judging the stage where the shift shock appears during the clutch engagement process Figure 5 and Figure 6 it is described as follows. Obtaining the stage where the shift shock appears in the static shift condition specifically means recording the maximum value of the rotational speed of the clutch driven end during the clutch locking process and the clutch control stage where the maximum value of the rotational speed of the driven end appears. Among them, taking Figure 5 as an example, the curves in the figure from top to bottom are the curves of the vehicle gear changing with time, the curves of the actual clutch pressure and the clutch control pressure changing with time, and the curves of the engine speed, the rotational speed of the clutch driving end, and the rotational speed of the clutch driven end changing directly with Figure 5 the abscissa of which is time. And the clutch control process of the static shift condition changing with time is divided into a pre-charging stage, an oil pressure stabilization stage, and an oil pressure rising stage in chronological order. If the maximum value of the rotational speed of the clutch driven end from the rotational speed curve of the clutch driven end appears in the oil pressure stabilization stage, the stage where the shift shock appears is the oil pressure stabilization stage. Similarly, Figure 6 if the maximum value of the rotational speed of the driven end appears in the oil pressure rising stage in

[0064] Adopting the above scheme, the stage where the shift shock occurs and the degree of the shift shock. It is judged whether an obvious static shift shock occurs by monitoring whether the maximum value of the rotational speed of the clutch driven end is greater than or equal to the hydraulic characteristic curve adjustment threshold. If it is greater than or equal to the hydraulic characteristic curve adjustment threshold, it indicates that an obvious static shift shock has occurred. At this time, adaptive adjustment is carried out, thus avoiding the shock caused by small-range fluctuations and avoiding unnecessary startup of the adaptive program, and improving the reliability of the adjustment.

[0065] According to another specific embodiment of the present invention, a clutch control method disclosed in the embodiment of the present invention, the clutch control stage is the time sequence of the clutch control process in the static gear shifting condition, and the clutch control stage includes a pre-charging stage, an oil pressure stabilizing stage, and an oil pressure rising stage.

[0066] By adopting the above scheme, control can be carried out more reliably and conveniently.

[0067] According to another specific embodiment of the present invention, a clutch control method disclosed in the embodiment of the present invention, as Figure 4 and Figure 5-Figure 8 shown, the adjustment parameters include the adjustment amplitude and the adjustment direction of the hydraulic characteristic curve.

[0068] Furthermore, the adjustment amplitude is obtained by looking up a table according to the maximum value of the rotational speed at the driven end of the clutch.

[0069] Furthermore, obtain the stage in which the maximum value of the rotational speed at the driven end of the clutch appears in the static gear shifting condition, and compare the relative positions of the actual pressure and the clutch control pressure of the clutch in the stage to obtain the adjustment direction.

[0070] Specifically, after identifying the rotational speed at the driven end greater than the adjustment threshold of the hydraulic characteristic curve, the adjustment amplitude is obtained by looking up a table with the maximum value of the rotational speed at the driven end. Those skilled in the art can obtain the relationship table between the rotational speed and the adjustment amplitude in advance according to the actual vehicle model through empirical values and experimental values. At this time, the greater the maximum value of the rotational speed at the driven end, the greater the adjustment amplitude of the hydraulic characteristic curve.

[0071] It should be noted that Figure 7-Figure 8 the abscissa in is the current, the ordinate is the clutch pressure, and the curve in the coordinate system is the hydraulic characteristic curve. Among them, the uppermost curve and the lowermost curve in the coordinate system are respectively the upper and lower limits of the hydraulic characteristic curve, that is, the theoretical values of the hydraulic characteristic curve.

[0072] Taking Figure 5 and Figure 7 as an example, Figure 5 in the oil pressure stabilizing stage, the situation where the maximum value of the rotational speed at the driven end is greater than the adjustment threshold of the hydraulic characteristic curve appears. At this time, obtain the maximum value of the rotational speed at the driven end and look up a table according to this value to obtain the hydraulic characteristic adjustment amplitude A. At the same time, since the maximum value of the rotational speed at the driven end appears in the oil pressure stabilizing stage, it indicates that the actual pressure is too high, that is, the original hydraulic characteristic curve is lower than the true hydraulic characteristic curve. As Figure 7 shown, at this time, the entire hydraulic characteristic curve needs to be translated upward, that is, the adjustment direction is upward, and the translation adjustment amplitude is A.

[0073] Similarly, as Figure 6 and Figure 8As shown, during the oil pressure rising stage, there appears a maximum speed of the driven end greater than the adjustment threshold of the hydraulic characteristic curve, and the adjustment amplitude can be obtained by looking up the table according to the maximum speed of the driven end.

[0074] If the maximum speed of the driven end appears during the oil pressure rising stage as shown in Figure 6 As shown, it indicates that the actual pressure is on the low side, that is, the original hydraulic characteristic curve is higher than the true hydraulic characteristic curve. As shown in Figure 8 As shown, the entire hydraulic characteristic curve needs to be translated downward, and the translation adjustment amplitude B is obtained by looking up the table according to the maximum speed of the driven end.

[0075] Adopting the above scheme, the method of indirectly judging whether the actual pressure of the clutch is on the high side or the low side by using the degree of static shift shock can achieve the adaptive correction of the deviation of the hydraulic characteristic curve without installing a pressure sensor, and the clutch hydraulic characteristic adaptive strategy enables the clutch control program in the transmission control unit to adapt to the deviation of different clutch hydraulic characteristic curves and the changes of the hydraulic characteristic curve during the clutch life cycle.

[0076] According to another specific embodiment of the present invention, a clutch control method disclosed by the embodiment of the present invention enters the static shift working condition when performing a static shift action in the adaptive program activation step.

[0077] Specifically, performing a static shift action means that the shift lever position is switched from P or N to D or R.

[0078] 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 only limited 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. A clutch control method, characterized in that, it includes the following steps: Adaptive program activation step: Determine whether the clutch enters the static shifting condition. If it enters the static shifting condition, then determine whether to activate the adaptive program for the clutch according to the activation conditions. The activation conditions include that the throttle is less than a preset throttle threshold, the braking pressure is greater than a preset braking pressure threshold, the vehicle speed is less than a preset vehicle speed threshold, the engine speed is less than a preset engine speed threshold, and the clutch has no current fault. If it is determined that the clutch activates the adaptive program, then enter the adaptive program execution step; If it does not enter the static shifting condition, then end the adaptive program activation step; Adaptive program execution step: Monitor whether there is a shifting shock exceeding a preset threshold during the process of the clutch completing locking, and obtain the stage at which the shifting shock appears in the static shifting condition. If the shifting shock exceeds the preset threshold, then obtain the adjustment parameters for adjusting the hydraulic characteristic curve of the clutch according to the stage, and enter the hydraulic characteristic curve adjustment step; if the shifting shock does not exceed the preset threshold, then end the adaptive program execution step; Hydraulic characteristic curve adjustment step: Adjust the hydraulic characteristic curve according to the adjustment parameters.

2. The clutch control method according to claim 1, characterized in that, the hydraulic characteristic curve adjustment step includes: Read the current hydraulic characteristic curve of the clutch from the memory, and adjust the current hydraulic characteristic curve according to the adjustment parameters to obtain a new hydraulic characteristic curve; If the new hydraulic characteristic curve does not exceed the theoretical threshold of the hydraulic characteristic curve, then update the new hydraulic characteristic curve to the memory. If the new hydraulic characteristic curve exceeds the theoretical threshold of the hydraulic characteristic curve, then do not update the new hydraulic characteristic curve to the memory.

3. The clutch control method according to claim 1, characterized in that, In the adaptive program activation step, if any moment during the period when the clutch completes the locking process does not meet the activation conditions, then terminate the adaptive program; If all moments during the period when the clutch completes the locking process meet the activation conditions, then record the stage at which the shifting shock appears.

4. The clutch control method according to claim 1, characterized in that, In the adaptive program execution step, the basis for monitoring the shifting shock is the rotational speed of the clutch driven end; and monitor the rotational speed of the clutch driven end during the process of the clutch completing locking; If the maximum value of the rotational speed of the clutch driven end is greater than or equal to the hydraulic characteristic curve adjustment threshold, then the shifting shock exceeds the preset threshold, record the clutch control stage at the time when the maximum value of the rotational speed of the clutch driven end appears, and obtain the adjustment parameters; If the maximum value of the rotational speed of the clutch driven end is less than the hydraulic characteristic curve adjustment threshold, then end the adaptive program.

5. The clutch control method according to claim 4, characterized in that, The clutch control phase is the chronological order of the clutch control process in the static gearshift condition, and the clutch control phase includes a pre-charging phase, an oil pressure stabilization phase, and an oil pressure rising phase.

6. The clutch control method according to claim 4, wherein, the adjustment parameters include the adjustment amplitude and the adjustment direction of the hydraulic characteristic curve.

7. The clutch control method according to claim 6, wherein, the adjustment amplitude is obtained by looking up a table according to the maximum value of the rotational speed of the clutch driven end.

8. The clutch control method according to claim 6, wherein, obtain the phase in which the maximum value of the rotational speed of the clutch driven end appears in the static gearshift condition, and compare the relative positions of the actual clutch pressure and the clutch control pressure in the phase to obtain the adjustment direction.

9. The clutch control method according to claim 1, wherein, in the adaptive program activation step, if a static gearshift action is performed, the clutch enters the static gearshift condition.

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