Control method and device for lock-up clutch

Abstract

The embodiment of the invention discloses a control method and device for a lock-up clutch, the lock-up clutch is used for achieving rigid connection between an engine and a turbine of a hydraulic torque converter, and when a vehicle meets the lock-up condition, first lock-up pressure, second lock-up pressure and third lock-up pressure are sequentially applied to the lock-up clutch, the second lock-up pressure is determined according to the preset pressure and the ith self-adaptive pressure, and if it is determined that the lock-up clutch meets the self-adaptive activation condition for the (i + 1) th time, according to the actual rotating speed change rate of the engine when the second lock-up pressure is applied to the lock-up clutch and within the preset time period before the third lock-up pressure is applied to the lock-up clutch, and determining the self-adaptive pressure increment according to the i-th self-adaptive pressure and the minimum target engine rotating speed change rate, and determining the (i + 1)-th self-adaptive pressure according to the i-th self-adaptive pressure and the self-adaptive pressure increment, so that the second locking pressure in the locking process can be determined based on the (i + 1)-th self-adaptive pressure, and the driving smoothness and the locking efficiency are balanced by controlling the pressure of the locking clutch.

Description

Technical Field

[0001] The present invention relates to the field of automobiles, and particularly to a control method and device for a lock-up clutch. Background Art

[0002] The torque converter component in an automatic transmission is responsible for transmitting the power of the engine to the transmission. The lock-up clutch in the torque converter is integrated on the turbine of the torque converter and can lock the lock-up clutch under specific working conditions, gradually pressing the friction plate of the lock-up clutch and the torque converter housing until a rigid connection is formed, so that the rotational speeds of the engine and the turbine are reduced until there is no slip.

[0003] During actual driving, when the vehicle speed is low or other shock-absorbing and buffering working conditions are required, the lock-up clutch is fully opened, and the torque converter transmits torque hydraulically to improve driving smoothness; when the vehicle speed is high and the working condition is stable, the pressure difference between both ends of the lock-up clutch is controlled to lock the lock-up clutch, forming a rigid mechanical transmission to achieve fuel economy. During the locking process of the lock-up clutch, the vehicle should maintain smooth engagement. However, due to the differences in the initial hardware itself and the performance differences caused by long-term driving, it is difficult for the current control method to achieve an ideal control effect. Summary of the Invention

[0004] To solve the above technical problems, the embodiments of the present application provide a control method and device for a lock-up clutch, which update the second lock-up pressure of the lock-up clutch by updating the i-th adaptive pressure to improve the vehicle smoothness during the locking process of the lock-up clutch.

[0005] The embodiments of the present application provide a control method for a lock-up clutch. The lock-up clutch is used to achieve rigid transmission between the engine and the turbine of the torque converter. The method includes:

[0006] When the vehicle meets the locking condition, the first lock-up pressure, the second lock-up pressure, and the third lock-up pressure are sequentially applied to the lock-up clutch. The first lock-up pressure is used to achieve pressure commutation of the lock-up clutch. The second lock-up pressure is determined according to a preset pressure and the i-th adaptive pressure. The third lock-up pressure is used to lock the lock-up clutch. i is an integer. When i is 0, the i-th adaptive pressure is the initial pressure;

[0007] If it is determined that the (i + 1)-th time the lock-up clutch meets the adaptive activation condition, an adaptive pressure increment is determined according to the actual engine speed change rate of the lock-up clutch when the second lock-up pressure is applied and the engine speed change rate in the previous preset time period before the third lock-up pressure is applied to the lock-up clutch, and the minimum target engine speed change rate;

[0008] Determine the (i + 1)-th adaptive pressure according to the i-th adaptive pressure and the adaptive pressure increment, and use the (i + 1)-th adaptive pressure as the latest adaptive pressure.

[0009] Optionally, if it is determined that the lock-up clutch satisfies the adaptive activation condition for the (i + 1)-th time, determine the adaptive pressure increment according to the actual engine speed change rate of the engine within a preset time period before the lock-up clutch is applied with the second lock-up pressure and before the lock-up clutch is applied with the third lock-up pressure, and the minimum target engine speed change rate, including:

[0010] If it is determined that the lock-up clutch satisfies the adaptive activation condition for the (i + 1)-th time, determine the minimum actual engine speed change rate of the engine according to the actual engine speed change rate of the engine within a preset time period before the lock-up clutch is applied with the second lock-up pressure and before the lock-up clutch is applied with the third lock-up pressure;

[0011] Determine the adaptive pressure increment according to the minimum actual engine speed change rate of the engine and the minimum target engine speed change rate.

[0012] Optionally, the determining the adaptive pressure increment according to the minimum actual engine speed change rate of the engine and the minimum target engine speed change rate includes:

[0013] If the difference between the minimum actual engine speed change rate of the engine and the minimum target engine speed change rate is less than the first threshold, determine the adaptive pressure increment according to the difference and the first calibration coefficient, the first threshold is less than zero, and the adaptive pressure increment is less than zero;

[0014] If the difference between the minimum actual engine speed change rate of the engine and the minimum target engine speed change rate is greater than the second threshold, determine the adaptive pressure increment according to the difference and the second calibration coefficient, the second threshold is greater than zero, and the adaptive pressure increment is greater than zero;

[0015] If the difference between the minimum actual engine speed change rate of the engine and the minimum target engine speed change rate is less than or equal to the second threshold and greater than or equal to the first threshold, determine that the adaptive pressure increment is zero.

[0016] Optionally, the second lock-up pressure is determined according to a preset pressure, a pressure threshold, and the i-th adaptive pressure, and the pressure threshold is positively correlated with the torque of the engine.

[0017] Optionally, the method further includes:

[0018] Obtain the i-th adaptive pressure corresponding to the actual operating condition parameters of the vehicle, where the actual operating condition parameters include the actual oil temperature and the actual engine torque;

[0019] Determine the minimum target engine speed change rate corresponding to the actual operating condition parameters;

[0020] Said determining the (i + 1)-th adaptive pressure according to the i-th adaptive pressure and the adaptive pressure increment includes:

[0021] Determine the (i + 1)-th adaptive pressure corresponding to the actual operating condition parameters of the vehicle according to the i-th adaptive pressure corresponding to the actual operating condition parameters of the vehicle and the adaptive pressure increment.

[0022] Optionally, the third lock-up pressure includes an open-loop lock-up pressure in a first stage and a closed-loop lock-up pressure in a second stage, and the method further includes:

[0023] Determine the open-loop lock-up pressure according to the second lock-up pressure and a preset step size;

[0024] Determine the closed-loop lock-up pressure according to the open-loop lock-up pressure and the difference between the engine speed and the turbine speed.

[0025] Optionally, the method further includes:

[0026] If the absolute value of the difference between the engine speed and the turbine speed is less than a preset value, apply a fourth lock-up pressure to the lock-up clutch, and the fourth lock-up pressure is greater than the third lock-up pressure.

[0027] An embodiment of the present application provides a control device for a lock-up clutch, where the lock-up clutch is used to achieve rigid transmission between an engine and a turbine of a torque converter, and the device includes:

[0028] A pressure application unit, configured to sequentially apply a first lock-up pressure, a second lock-up pressure, and a third lock-up pressure to the lock-up clutch when the vehicle meets the lock-up condition, where the first lock-up pressure is used to achieve pressure commutation of the lock-up clutch, the second lock-up pressure is determined according to a preset pressure and the i-th adaptive pressure, the third lock-up pressure is used to achieve lock-up of the lock-up clutch, i is an integer, and when i is 0, the i-th adaptive pressure is an initial pressure;

[0029] A pressure increment determination unit, configured to determine an adaptive pressure increment according to the actual engine speed change rate and the minimum target engine speed change rate when the lock-up clutch is applied with the second lock-up pressure and in a preset time period before the lock-up clutch is applied with the third lock-up pressure if it is determined that the lock-up clutch meets the adaptive activation condition for the (i + 1)-th time;

[0030] A pressure update unit, configured to determine the (i + 1)-th adaptive pressure according to the i-th adaptive pressure and the adaptive pressure increment, and use the (i + 1)-th adaptive pressure as the latest adaptive pressure.

[0031] Optionally, the pressure increment determination unit includes:

[0032] A minimum change rate determination unit, configured to determine the minimum actual engine speed change rate according to the actual engine speed change rate of the engine within a preset time period before the (i + 1)-th time the lock-up clutch satisfies the adaptive activation condition when the lock-up clutch is applied with the second lock-up pressure and when the lock-up clutch is applied with the third lock-up pressure;

[0033] A pressure increment determination subunit, configured to determine the adaptive pressure increment according to the minimum actual engine speed change rate of the engine and the minimum target engine speed change rate.

[0034] Optionally, the pressure increment determination subunit is specifically configured to:

[0035] If the difference between the minimum actual engine speed change rate of the engine and the minimum target engine speed change rate is less than a first threshold, determine the adaptive pressure increment according to the difference and a first calibration coefficient, where the first threshold is less than zero and the adaptive pressure increment is less than zero;

[0036] If the difference between the minimum actual engine speed change rate of the engine and the minimum target engine speed change rate is greater than a second threshold, determine the adaptive pressure increment according to the difference and a second calibration coefficient, where the second threshold is greater than zero and the adaptive pressure increment is greater than zero;

[0037] If the difference between the minimum actual engine speed change rate of the engine and the minimum target engine speed change rate is less than or equal to the second threshold and greater than or equal to the first threshold, determine that the adaptive pressure increment is zero.

[0038] Optionally, the second lock-up pressure is determined according to a preset pressure, a pressure threshold, and the i-th adaptive pressure, and the pressure threshold is positively correlated with the torque of the engine.

[0039] Optionally, the device further includes:

[0040] An adaptive pressure acquisition unit, configured to acquire the i-th adaptive pressure corresponding to the actual operating condition parameters of the vehicle, where the actual operating condition parameters include the actual oil temperature and the actual engine torque;

[0041] A speed change rate determination unit, configured to determine the minimum target engine speed change rate corresponding to the actual operating condition parameters;

[0042] The pressure update unit is specifically configured to:

[0043] Determine the (i + 1)-th adaptive pressure corresponding to the actual operating condition parameters of the vehicle according to the i-th adaptive pressure corresponding to the actual operating condition parameters of the vehicle and the adaptive pressure increment.

[0044] Optionally, the third locking pressure includes an open-loop locking pressure in a first stage and a closed-loop locking pressure in a second stage, and the device further includes:

[0045] An open-loop locking pressure determination unit, configured to determine the open-loop locking pressure according to the second locking pressure and a preset step size;

[0046] A closed-loop locking pressure determination unit, configured to determine the closed-loop locking pressure according to the open-loop locking pressure and the difference between the engine speed and the turbine speed.

[0047] Optionally, the device further includes:

[0048] A fourth locking pressure application unit, configured to apply a fourth locking pressure to the locking clutch if the absolute value of the difference between the engine speed and the turbine speed is less than a preset value, and the fourth locking pressure is greater than the third locking pressure.

[0049] The embodiment of the present application provides a control method and device for a lock-up clutch. The lock-up clutch is used to achieve rigid transmission between the engine and the turbine of the torque converter. In this method, the i-th adaptive pressure can be obtained. When i is an integer and i = 0, the i-th adaptive pressure is the initial pressure. When the vehicle meets the lock-up condition, the first lock-up pressure, the second lock-up pressure, and the third lock-up pressure are sequentially applied to the lock-up clutch. The first lock-up pressure is used to achieve the pressure reversal of the lock-up clutch. The second lock-up pressure is determined according to the preset pressure and the i-th adaptive pressure. The third lock-up pressure is used to achieve the lock-up of the lock-up clutch. If it is determined that the lock-up clutch meets the adaptive activation condition for the (i + 1)-th time, then according to the actual engine speed change rate of the engine during the period when the second lock-up pressure is applied to the lock-up clutch and the previous preset time period before the third lock-up pressure is applied to the lock-up clutch, and the minimum target engine speed change rate, the adaptive pressure increment is determined. According to the i-th adaptive pressure and the adaptive pressure increment, the (i + 1)-th adaptive pressure is determined. In this way, each adaptive pressure is determined according to the actual engine speed change rate. Therefore, the determined adaptive pressure better meets the actual situation of the vehicle. Accordingly, the latest adaptive pressure can be updated when the (i + 1)-th adaptive activation condition is met, and the second lock-up pressure during the lock-up process is determined based on the i-th adaptive pressure, realizing the continuous optimization and update of the second lock-up pressure, improving the rationality of the second lock-up pressure, avoiding the problem of poor driving smoothness caused by too large a second lock-up pressure, and the problem of low lock-up efficiency caused by too small a second lock-up pressure. By controlling the pressure of the lock-up clutch, the driving smoothness and the lock-up efficiency are balanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments recorded in the present application. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings.

[0051] Figure 1 FIG. is a schematic diagram of a control process provided by an embodiment of the present application;

[0052] Figure 2 FIG. is a flowchart of a control method for a lock-up clutch provided by an embodiment of the present application;

[0053] Figure 3 FIG. is a flowchart of another control method for a lock-up clutch provided by an embodiment of the present application;

[0054] Figure 4 FIG. is a structural block diagram of a control device for a lock-up clutch provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0055] To make the above objects, features, and advantages of the present application more apparent and understandable, the following provides a detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings.

[0056] In the following description, numerous specific details are set forth to facilitate a thorough understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0057] During actual driving, when the driver starts, the lock-up clutch is fully open. After meeting the lock-up condition, the control of the lock-up clutch starts to lock. Refer to Figure 1 As shown, it is a schematic diagram of a control process provided by an embodiment of the present application. After the driver starts, the throttle opening rises to a certain value, and the engine torque and engine speed gradually increase. After meeting the lock-up condition, locking starts. The lock-up condition can be that the vehicle speed is relatively high and the working condition is stable. The judgment conditions for a relatively high vehicle speed and a stable working condition can be determined according to the actual situation. During the process of the engine speed increasing, the speed of the turbine can also gradually increase to reduce the difference between the engine speed and the turbine speed and improve the engagement efficiency.

[0058] After starting to lock, the lock-up clutch enters the locking process. The locking process of the lock-up clutch can include a pre-charge stage and an engagement stage. The pre-charge stage includes a pressure reversal stage (i.e., the first pre-charge stage) and a stable pressure build-up stage (i.e., the second pre-charge stage). The pressure reversal stage applies a certain pressure to the lock-up clutch to complete the pressure reversal of the lock-up clutch. The stable pressure build-up stage maintains a certain lock-up pressure for a period of time to achieve stable pressure reduction for the lock-up clutch. The lock-up clutch theoretically does not transmit torque during the pre-charge stage, which is a preparation stage for the engagement stage. At this time, the clearance of the friction pair composed of the lock-up clutch friction plate and the inner rigid surface of the pump wheel housing is eliminated, and it has little effect on the speed difference synchronization. The engagement stage can include an open-loop control stage and a closed-loop control stage. The engagement stage performs pressurization control on the lock-up clutch to gradually synchronize the engine speed and the turbine speed, realizing the locking of the lock-up clutch. After the engine speed and the turbine speed are synchronized (for example, the speed difference is less than a preset value), the lock-up clutch is fully locked.

[0059] During the locking process of the lock-up clutch, the vehicle should maintain smooth engagement. However, it is difficult to achieve an ideal control effect with the current control method. This is because of the performance differences caused by the hardware itself or durable driving, which easily leads to the problem that the lock-up pressure in the stable pressure reduction stage does not match the actual working condition of the vehicle. Refer to Figure 1As shown, if the lock-up pressure is too high, it will cause the engine speed to drop too quickly during the initial stage of the engagement phase after the second-stage pre-charge attempt or the engagement phase after the pre-charge phase, and the engine speed and the turbine speed will synchronize too quickly. Usually, the driver will feel a certain impact. If the lock-up pressure is too low, it will cause the speed difference between the engine and the turbine cannot be eliminated for some time after the pre-charge phase ends, the speed synchronization time is too long, and the lock-up efficiency is low.

[0060] Based on this, the embodiments of the present application provide a control method and device for a lock-up clutch. The lock-up clutch is used to realize the rigid transmission between the engine and the turbine of the torque converter. In this method, the i-th adaptive pressure can be obtained, where i is an integer. When i is 0, the i-th adaptive pressure is the initial pressure. When the vehicle meets the lock-up condition, the first lock-up pressure, the second lock-up pressure, and the third lock-up pressure are applied to the lock-up clutch in sequence. The first lock-up pressure is used to realize the pressure reversal of the lock-up clutch. The second lock-up pressure is determined according to the preset pressure and the latest adaptive pressure, and the latest adaptive pressure is the i-th adaptive pressure. The third lock-up pressure is used to realize the lock-up of the lock-up clutch. If it is determined that the lock-up clutch meets the adaptive activation condition for the (i + 1)-th time, then according to the actual engine speed change rate of the engine when the second lock-up pressure is applied to the lock-up clutch and the previous preset time period before the third lock-up pressure is applied to the lock-up clutch, as well as the minimum target engine speed change rate, the adaptive pressure increment is determined. According to the i-th adaptive pressure and the adaptive pressure increment, the (i + 1)-th adaptive pressure is determined as the latest adaptive pressure. In this way, each adaptive pressure is determined according to the actual engine speed change rate. Therefore, the determined adaptive pressure better meets the actual situation of the vehicle. Accordingly, the latest adaptive pressure can be updated when the (i + 1)-th adaptive activation condition is met, and the second lock-up pressure during the lock-up process is determined based on the (i + 1)-th adaptive pressure, realizing the continuous optimization and update of the second lock-up pressure, improving the rationality of the second lock-up pressure, avoiding the problem of poor driving smoothness caused by too high second lock-up pressure, and the problem of low lock-up efficiency caused by too low second lock-up pressure. By controlling the pressure of the lock-up clutch, the driving smoothness and the lock-up efficiency are balanced.

[0061] The following will combine the accompanying drawings to illustrate in detail the specific implementation manners of a control method and device for a lock-up clutch provided by the embodiments of the present application through embodiments.

[0062] Reference Figure 2 The flowchart of a control method for a lock-up clutch provided by the embodiments of the present application is shown. This method can be applied to a Transmission Control Unit (TCU) and may include the following steps.

[0063] S101, when the vehicle meets the lock-up condition, apply the first lock-up pressure, the second lock-up pressure, and the third lock-up pressure to the lock-up clutch in sequence.

[0064] In the embodiment of the present application, the torque converter includes a lock-up clutch. The lock-up clutch is used to achieve rigid transmission between the engine and the turbine of the torque converter, so that direct transmission between the pump impeller and the turbine is achieved when the lock-up clutch is locked, thereby transmitting the power of the engine to the transmission. The lock-up clutch may include friction plates. The friction plates are connected to the turbine. Applying a certain pressure to the friction plates can cause the friction plates to engage with the torque converter housing, and the rotational speeds gradually synchronize under the action of friction force.

[0065] During the locking process of the lock-up clutch, the latest adaptive pressure of the lock-up clutch can be obtained. Taking the i-th adaptive pressure as the latest adaptive pressure as an example, the i-th adaptive pressure is used to adjust the locking pressure in the pre-charge stage. i is an integer. When i is 0, the i-th adaptive pressure is the initial pressure, and the initial pressure can be set according to the actual situation. For example, it can be zero. The i-th adaptive pressure can be stored in the storage area for lookup, or can be called as an execution result. The storage area can be a permanently stored storage area and will not be lost when the vehicle's power is turned off, so that the i-th adaptive pressure can be applicable throughout the life cycle of the vehicle. That is to say, i can increase throughout the life cycle of the vehicle, and the i-th adaptive pressure is also continuously updated. That is to say, the i-th adaptive pressure obtained when the vehicle is powered on for the first time is the initial pressure, and the i-th adaptive pressure obtained when the vehicle is powered on for the nth time is the adaptive pressure adjusted during the previous power-on.

[0066] Referring to the subsequent description, when i is not 1, the i-th adaptive pressure can be determined according to the (i - 1)-th adaptive pressure. The i-th adaptive pressure is used to determine the second locking pressure, so it needs to be obtained before the second locking pressure is applied. It can be obtained when the vehicle meets the locking condition, or can be obtained before the vehicle meets the locking condition, or can also be obtained during the application of the first locking pressure, or after the application of the first locking pressure.

[0067] The i-th adaptive pressure can correspond to the actual operating condition parameters of the vehicle. The actual operating condition parameters are determined by the actual oil temperature and the actual engine torque. Therefore, the corresponding i-th adaptive pressure can be determined according to the actual oil temperature and the actual engine torque of the vehicle. The actual operating condition parameters are the operating condition parameters when the i-th adaptive pressure is obtained. Different i-th adaptive pressures can be determined under different actual oil temperatures, and different i-th adaptive pressures can also be determined under different actual engine torques. When the i-th adaptive pressure is used to adjust the pre-charge pressure, different pre-charge pressures can be provided under different actual operating condition parameters, so that good control effects can be achieved under different operating condition parameters. The transmission characteristics of different oil temperatures result in different hydraulic transmission characteristics, and a higher engine torque can correspond to a greater locking pressure. Based on this, the i-th adaptive pressure can be determined. For example, the i-th adaptive pressure can be set to be positively correlated with the actual oil temperature and positively correlated with the actual engine torque.

[0068] In the embodiments of the present application, when the vehicle meets the locking condition, the locking clutch can be locked. During the locking process, the first locking pressure, the second locking pressure, and the third locking pressure can be sequentially applied to the locking clutch. The application stage of the first locking pressure is the aforementioned first pre-charging stage, that is, the pressure commutation stage. The application stage of the second locking pressure corresponds to the aforementioned second pre-charging stage, that is, the stable pressure building stage. The application stage of the third locking pressure corresponds to the aforementioned engagement stage.

[0069] That is to say, the first locking pressure is used to achieve the pressure commutation of the locking clutch, the second locking pressure is used to achieve the stable pressure building of the locking clutch, and the third locking pressure is used to achieve the locking of the locking clutch. The first locking pressure is usually a pressure greater than the second locking pressure, which can be determined according to the performance of the locking clutch. The second locking pressure can be determined according to a preset pressure and the i-th adaptive pressure. The preset pressure can be a commutation pressure, also called a start engagement pressure. The i-th adaptive pressure is an adaptive pressure for the locking pressure, which is used to adjust the preset pressure to obtain the second locking pressure. The i-th adaptive high pressure and the locking pressure can be positively correlated. For example, the second locking pressure can be the sum of the preset pressure and the i-th adaptive pressure. In this way, by setting the i-th adaptive pressure, the second locking pressure can be increased or decreased.

[0070] Specifically, the second locking pressure can also be determined according to a pressure threshold, that is, the second locking pressure can be determined according to a preset pressure, a pressure threshold, and the i-th adaptive pressure. The pressure threshold is positively correlated with the torque of the engine. In this way, when the torque of the engine is large, the second locking pressure is relatively high. When the torque of the engine is small, the second locking pressure is relatively low, realizing the dynamic configuration of the second locking pressure and balancing the locking efficiency and vehicle smoothness.

[0071] The third locking pressure can be determined based on the second locking pressure. Specifically, the engagement stage of applying the third locking pressure can also be divided into a first stage and a second stage. The first stage can be called an open-loop control stage, and the second stage can be called a closed-loop control stage. Refer to Figure 1As shown, the third locking pressure may include the open-loop locking pressure in the first stage and the closed-loop locking pressure in the second stage. The open-loop locking pressure can be determined according to the second locking pressure and a preset step size, and the change rate of the open-loop locking pressure can be constant. In this way, the third locking pressure in the open-loop pressurization stage increases rapidly, the frictional torque increases, the engine speed and the turbine speed start to synchronize, the engine speed starts to drop, and the turbine speed rises. The closed-loop locking pressure can be determined according to the open-loop locking pressure and the difference between the engine speed and the turbine speed. The change rate of the closed-loop locking pressure can be constant or inversely correlated with the difference. In this way, in the closed-loop pressurization stage, as the engine speed and the turbine speed approach, the third locking pressure increases slowly, and the engine speed and the turbine speed are further stably synchronized until the lock-up clutch locks up.

[0072] In addition, if after applying the third locking pressure to the lock-up clutch, the absolute value of the difference between the engine speed and the turbine speed is less than a preset value, it is determined that the lock-up clutch is fully locked, and then the fourth locking pressure can be applied to the lock-up clutch. The fourth locking pressure is greater than the third locking pressure to keep the lock-up clutch in the locked state and realize the mechanical transmission between the engine and the turbine. There may be a buffer pressure between the third locking pressure and the fourth locking pressure.

[0073] S102. If it is determined that the (i + 1)-th time the lock-up clutch meets the adaptive activation condition, determine the adaptive pressure increment according to the actual engine speed change rate of the lock-up clutch when the second locking pressure is applied and the engine in the preset time period before the third locking pressure is applied to the lock-up clutch, and the minimum target engine speed change rate.

[0074] In the embodiment of the present application, if it is determined that the (i + 1)-th time the lock-up clutch meets the adaptive activation condition, the engine speed during the locking stage of the lock-up clutch can be monitored. If the engine speed drops too fast during the pre-charge stage, it means that the locking pressure is too high. If there is no obvious drop in the engine speed for a period of time after the pre-charge stage, it means that the locking pressure is too low. Since the turbine speed shows an upward trend, there may be misjudgment when using the speed difference between the engine and the turbine as the judgment signal for whether the locking pressure is reasonable. Therefore, it is relatively reasonable to indicate the unreasonable direction and adjustment direction of the locking pressure through the change of the engine speed.

[0075] Specifically, if it is determined that the lock-up clutch satisfies the adaptive activation condition for the (i + 1)-th time, the actual engine speed change rate can be determined based on the actual engine speed change rate when the lock-up clutch is applied with the second lock-up pressure and the actual engine speed change rate during the preset time period before the lock-up clutch is applied with the third lock-up pressure. Then, the adaptive pressure increment can be determined based on the minimum actual engine speed change rate and the minimum target engine speed change rate. Among them, the actual engine speed change rate when the lock-up clutch is applied with the second lock-up pressure should theoretically be slow without obvious downward pull. The preset time period before the lock-up clutch is applied with the third lock-up pressure is a relatively short time period, which can be determined according to the actual situation. During this time period, the lock-up clutch is in the initial stage of locking, and the engine speed should theoretically have a reasonable change rate. The stage when the lock-up clutch is applied with the second lock-up pressure and the preset time period before the lock-up clutch is applied with the third lock-up pressure are the engine speed monitoring stages. This stage is the adaptive stage, and the duration of this stage is the adaptive duration.

[0076] During the engine speed monitoring stage, the absolute value of the minimum actual engine speed change rate should theoretically be less than a certain reasonable threshold. However, unreasonable lock-up pressure may cause the actual engine speed to rise or drop rapidly. When the minimum actual engine speed change rate of the engine is too large or too small, it indicates that the second lock-up pressure is unreasonable and needs to be adjusted.

[0077] During specific implementation, if the difference between the minimum actual engine speed change rate and the minimum target engine speed change rate is less than the first threshold, the adaptive pressure increment can be determined based on this difference and the first calibration coefficient. The first threshold is less than zero, and the adaptive pressure increment is less than zero. That is to say, when the minimum actual engine speed change rate is negative and the absolute value of the minimum actual engine speed change rate is significantly larger than the absolute value of the minimum target engine speed change rate, it indicates that the engine speed drops too fast and the second lock-up pressure is too large. Therefore, it can be determined that the adaptive pressure increment is less than zero to suppress the second lock-up pressure. If the difference between the minimum actual engine speed change rate and the minimum target engine speed change rate is greater than the second threshold, the adaptive pressure increment can be determined based on this difference and the second calibration coefficient. The second threshold is greater than zero, and the adaptive pressure increment is greater than zero. That is to say, when the minimum actual engine speed change rate is negative and the absolute value of the minimum actual engine speed change rate is significantly smaller than the absolute value of the minimum target engine speed change rate, it indicates that the engine speed drops slowly and the second lock-up pressure is too small. Therefore, it can be determined that the adaptive pressure increment is greater than zero to increase the second lock-up pressure. If the difference between the minimum actual engine speed change rate and the minimum target engine speed change rate is less than or equal to the second threshold and greater than or equal to the first threshold, it indicates that the minimum actual engine speed change rate and the minimum target engine speed change rate do not differ much, and the adaptive convergence is achieved this time, and the second lock-up pressure is appropriate. Therefore, it can be determined that the adaptive pressure increment is zero, and there is no need to adjust the second lock-up pressure.

[0078] Among them, the minimum target engine speed change rate can be an appropriate negative value, and its specific value can be determined according to the actual situation. The absolute value of the second threshold can be equal to the absolute value of the first threshold, or greater than or less than the absolute value of the first threshold. The first calibration coefficient and the second calibration coefficient can be determined according to the actual situation. Denote the difference between the minimum actual engine speed change rate and the minimum target engine speed change rate as the change rate difference, and the adaptive pressure increment can be the product of the first calibration coefficient or the second calibration coefficient and the change rate difference.

[0079] In the embodiment of the present application, when the adaptive activation condition is satisfied, the aforementioned actual rotational speed change rate and the minimum target engine rotational speed change rate can be obtained, and then S102 is executed. The rotational speed change rate is the rotational speed change rate in the front section of applying the second lock-up pressure and the third lock-up pressure. Therefore, the monitoring of the engine is synchronously executed with the application of the second lock-up pressure and the third lock-up pressure in the front section in S101. The judgment of the adaptive activation condition can be executed before applying the second lock-up pressure, for example, it can be executed during the application of the first lock-up pressure. If the adaptive activation condition is not satisfied, the adaptive process can be exited, that is, the adaptive pressure is not adjusted and the original value is retained. The adaptive activation condition is usually entering the pre-charge state (that is, starting to apply the first lock-up pressure to the lock-up clutch) and satisfying certain stability conditions and fault-free conditions. The stability conditions and fault-free conditions can be determined according to the actual situation, such as stable vehicle speed, etc.

[0080] In the embodiment of the present application, the minimum target engine rotational speed change rate can be related to the actual working conditions of the vehicle. Different actual working condition parameters can correspond to different minimum target engine rotational speed change rates. In this way, the corresponding minimum target engine rotational speed change rate can also be determined according to the actual working condition parameters. The minimum target engine rotational speed change rate is used to compare with the actual rotational speed change rate under the actual working condition parameters to obtain the adaptive pressure increment under the actual working condition parameters, so as to adjust the i-th adaptive pressure under the actual working condition parameters, realize the gradual update of the adaptive pressure under the actual working condition parameters, and make the adjustment of the adaptive pressure more refined.

[0081] S103. Determine the (i + 1)-th adaptive pressure according to the i-th adaptive pressure and the adaptive pressure increment.

[0082] After determining the adaptive pressure increment, the (i + 1)-th adaptive pressure can be determined according to the i-th adaptive pressure and the adaptive pressure increment. The (i + 1)-th adaptive pressure is used as the latest adaptive pressure and is queried and called when the lock-up condition is satisfied next time. In this way, each adaptive pressure is determined according to the actual engine rotational speed change rate. Therefore, the determined adaptive pressure better meets the actual situation of the vehicle. Accordingly, the second lock-up pressure can be determined based on the i-th adaptive pressure when the lock-up condition is satisfied, and the second lock-up pressure can be determined according to the (i + 1)-th adaptive pressure after the adaptive pressure is updated, realizing the continuous optimization and update of the second lock-up pressure, improving the rationality of the second lock-up pressure, avoiding the problem of poor driving smoothness caused by too large second lock-up pressure, and the problem of low lock-up efficiency caused by too small second lock-up pressure, and balancing driving smoothness and lock-up efficiency. Among them, the (i + 1)-th adaptive pressure can be the sum of the i-th adaptive pressure and the adaptive pressure increment, that is, the (i + 1)-th adaptive pressure = the i-th adaptive pressure + the adaptive pressure increment.

[0083] After determining the (i + 1)-th adaptive pressure, the (i + 1)-th adaptive pressure can be stored, for example, stored in a storage area of permanent storage, so that the (i + 1)-th adaptive pressure can be used after power-off and power-on. In this way, when the vehicle meets the locking condition, the second locking pressure can be determined according to the (i + 1)-th adaptive pressure, and then the locking clutch can be controlled, and the (i + 2)-th adaptive pressure can be determined according to the state of the engine, and so on, so as to achieve the expected rotational speed synchronization effect, improve the versatility of the control software, and meet the driving smoothness.

[0084] In the embodiments of the present application, the determination of the adaptive pressure can be related to the actual working condition parameters of the vehicle. Under different actual working condition parameters, different minimum target engine speed change rates can be corresponding, which are used to compare with the actual speed change rate under the actual working condition parameters to obtain the adaptive pressure increment under the actual working condition parameters. The adaptive pressure increment under the actual working condition parameters is used to adjust the i-th adaptive pressure under the actual working condition parameters to obtain the (i + 1)-th adaptive pressure under the actual working condition parameters, that is, the (i + 1)-th adaptive pressure corresponding to the actual working condition parameters of the vehicle can be determined according to the i-th adaptive pressure and the adaptive pressure increment corresponding to the actual working condition parameters of the vehicle. In this way, the adaptive adjustment of the locking pressure can be carried out respectively for different actual working condition parameters, the second locking pressure can be dynamically determined according to the actual working condition parameters, the rotational speed synchronization control effect can be improved, and the driving smoothness and the locking efficiency can be balanced. During the entire life cycle, the adaptive pressures under different actual working condition parameters are continuously used and updated until the second locking pressure reaches a suitable value, the actual change rate of the engine and the target change rate are close, and the speed difference control requirements during the stable pressure building stage and for a period of time thereafter are met, realizing the smooth engagement of the shown clutch.

[0085] The control method of the locking clutch will be illustrated by examples below. Refer to Figure 3 As shown in the flowchart of another control method of the locking clutch provided by the embodiments of the present application, the method may include:

[0086] S201, when the vehicle meets the locking condition, apply a first locking pressure to the locking clutch;

[0087] S202, determine the second locking pressure corresponding to the actual working condition parameters according to the preset pressure, the pressure threshold and the i-th adaptive pressure;

[0088] S203, apply the second locking pressure and the third locking pressure to the locking clutch in sequence.

[0089] Wherein, after determining that the locking condition is met in S201, S204 - S208 can also be executed.

[0090] S204, determine whether the adaptive activation condition is met. If so, execute S205; if not, end the process.

[0091] S205, obtain the actual engine speed change rate when the lock-up clutch is applied with the second lock-up pressure and the minimum target engine speed change rate corresponding to the actual operating condition parameters within a preset time period before the lock-up clutch is applied with the third lock-up pressure.

[0092] S206, determine the adaptive pressure increment based on the actual engine speed change rate and the minimum target engine speed change rate.

[0093] S207, determine the (i + 1)-th adaptive pressure corresponding to the actual operating condition parameters based on the i-th adaptive pressure and the adaptive pressure increment. The (i + 1)-th adaptive pressure can be used as the latest adaptive pressure and can be stored, thus ending the current adaptive process.

[0094] For the specific implementation of each step in the above example, reference can be made to the foregoing description and will not be elaborated here.

[0095] The embodiment of the present application provides a control method for a lock-up clutch. The lock-up clutch is used to achieve rigid transmission between the engine and the turbine of the torque converter. In this method, the i-th adaptive pressure can be obtained, where i is an integer. When i is 0, the i-th adaptive pressure is the initial pressure. When the vehicle meets the lock-up condition, the first lock-up pressure, the second lock-up pressure, and the third lock-up pressure are sequentially applied to the lock-up clutch. The first lock-up pressure is used to achieve the pressure reversal of the lock-up clutch. The second lock-up pressure is determined based on the preset pressure and the i-th adaptive pressure. The third lock-up pressure is used to achieve the lock-up of the lock-up clutch. If it is determined that the lock-up clutch meets the adaptive activation condition for the (i + 1)-th time, then based on the actual engine speed change rate when the lock-up clutch is applied with the second lock-up pressure and the minimum target engine speed change rate within a preset time period before the lock-up clutch is applied with the third lock-up pressure, the adaptive pressure increment is determined. Based on the i-th adaptive pressure and the adaptive pressure increment, the (i + 1)-th adaptive pressure is determined. In this way, each adaptive pressure is determined according to the actual engine speed change rate, so the determined adaptive pressure better meets the actual situation of the vehicle. Accordingly, when the lock-up clutch meets the adaptive activation condition for the (i + 1)-th time, the latest adaptive pressure can be updated, and based on the (i + 1)-th adaptive pressure, the second lock-up pressure during the lock-up process is determined, realizing the continuous optimization and update of the second lock-up pressure, improving the rationality of the second lock-up pressure, avoiding the problem of poor driving smoothness caused by too large a second lock-up pressure, and the problem of low lock-up efficiency caused by too small a second lock-up pressure, and balancing the driving smoothness and the lock-up efficiency through the pressure control of the lock-up clutch.

[0096] Based on the above control method for the lock-up clutch, the embodiment of the present application further provides a control device for the lock-up clutch. Refer toFigure 4 As shown in the figure, it is a structural block diagram of a control device for a lock-up clutch provided by an embodiment of the present application. The lock-up clutch is used to achieve rigid transmission between the engine and the turbine of the torque converter. The device may include:

[0097] A pressure application unit 110, configured to sequentially apply a first lock-up pressure, a second lock-up pressure, and a third lock-up pressure to the lock-up clutch when the vehicle meets the lock-up condition. The first lock-up pressure is used to achieve pressure commutation of the lock-up clutch. The second lock-up pressure is determined according to a preset pressure and the i-th adaptive pressure. The third lock-up pressure is used to lock up the lock-up clutch. When i is an integer and i is 0, the i-th adaptive pressure is an initial pressure;

[0098] A pressure increment determination unit 120, configured to determine an adaptive pressure increment according to the actual engine speed change rate of the engine during the period when the lock-up clutch is applied with the second lock-up pressure and a preset period before the lock-up clutch is applied with the third lock-up pressure, and the minimum target engine speed change rate if it is determined that the lock-up clutch meets the adaptive activation condition for the (i + 1)-th time;

[0099] A pressure update unit 130, configured to determine the (i + 1)-th adaptive pressure according to the i-th adaptive pressure and the adaptive pressure increment, and the (i + 1)-th adaptive pressure is used as the latest adaptive pressure.

[0100] Optionally, the pressure increment determination unit includes:

[0101] A minimum change rate determination unit, configured to determine the minimum actual engine speed change rate of the engine according to the actual engine speed change rate of the engine during the period when the lock-up clutch is applied with the second lock-up pressure and a preset period before the lock-up clutch is applied with the third lock-up pressure if it is determined that the lock-up clutch meets the adaptive activation condition for the (i + 1)-th time;

[0102] A pressure increment determination subunit, configured to determine the adaptive pressure increment according to the minimum actual engine speed change rate of the engine and the minimum target engine speed change rate.

[0103] Optionally, the pressure increment determination subunit is specifically configured to:

[0104] If the difference between the minimum actual engine speed change rate of the engine and the minimum target engine speed change rate is less than a first threshold, determine the adaptive pressure increment according to the difference and a first calibration coefficient. The first threshold is less than zero, and the adaptive pressure increment is less than zero;

[0105] If the difference between the actual minimum engine speed change rate of the engine and the minimum target engine speed change rate is greater than a second threshold, an adaptive pressure increment is determined according to the difference and a second calibration coefficient, the second threshold is greater than zero, and the adaptive pressure increment is greater than zero;

[0106] If the difference between the actual minimum engine speed change rate of the engine and the minimum target engine speed change rate is less than or equal to the second threshold and greater than or equal to the first threshold, the adaptive pressure increment is determined to be zero.

[0107] Optionally, the second lock-up pressure is determined according to a preset pressure, a pressure threshold, and the i-th adaptive pressure, and the pressure threshold is positively correlated with the torque of the engine.

[0108] Optionally, the device further includes:

[0109] An adaptive pressure acquisition unit, configured to acquire the i-th adaptive pressure corresponding to the actual operating condition parameters of the vehicle, where the actual operating condition parameters include the actual oil temperature and the actual engine torque;

[0110] A speed change rate determination unit, configured to determine the minimum target engine speed change rate corresponding to the actual operating condition parameters;

[0111] The pressure update unit is specifically configured to:

[0112] Determine the (i + 1)-th adaptive pressure corresponding to the actual operating condition parameters of the vehicle according to the i-th adaptive pressure corresponding to the actual operating condition parameters of the vehicle and the adaptive pressure increment.

[0113] Optionally, the third lock-up pressure includes an open-loop lock-up pressure in a first stage and a closed-loop lock-up pressure in a second stage, and the device further includes:

[0114] An open-loop lock-up pressure determination unit, configured to determine the open-loop lock-up pressure according to the second lock-up pressure and a preset step;

[0115] A closed-loop lock-up pressure determination unit, configured to determine the closed-loop lock-up pressure according to the open-loop lock-up pressure and the difference between the engine speed and the turbine speed.

[0116] Optionally, the device further includes:

[0117] A fourth lock-up pressure application unit, configured to apply a fourth lock-up pressure to the lock-up clutch if the absolute value of the difference between the engine speed and the turbine speed is less than a preset value, and the fourth lock-up pressure is greater than the third lock-up pressure.

[0118] An embodiment of the present application provides a control device for a lock-up clutch. The lock-up clutch is used to achieve rigid transmission between the engine and the turbine of the torque converter. The i-th adaptive pressure can be obtained, where i is an integer. When i is 0, the i-th adaptive pressure is the initial pressure. When the vehicle meets the lock-up condition, the first lock-up pressure, the second lock-up pressure, and the third lock-up pressure are sequentially applied to the lock-up clutch. The first lock-up pressure is used to achieve pressure commutation of the lock-up clutch. The second lock-up pressure is determined according to a preset pressure and the i-th adaptive pressure. The third lock-up pressure is used to lock up the lock-up clutch. If it is determined that the lock-up clutch meets the adaptive activation condition for the (i + 1)-th time, then according to the actual engine speed change rate of the engine during the period before the lock-up clutch is applied with the second lock-up pressure and within a preset time period before the lock-up clutch is applied with the third lock-up pressure, and the minimum target engine speed change rate, an adaptive pressure increment is determined. According to the i-th adaptive pressure and the adaptive pressure increment, the (i + 1)-th adaptive pressure is determined. In this way, each adaptive pressure is determined according to the actual engine speed change rate, so the determined adaptive pressure better meets the actual situation of the vehicle. Accordingly, the latest adaptive pressure can be updated when the (i + 1)-th adaptive activation condition is met, and the second lock-up pressure during the lock-up process is determined based on the (i + 1)-th adaptive pressure, realizing continuous optimization and update of the second lock-up pressure, improving the rationality of the second lock-up pressure, avoiding the problem of poor driving smoothness caused by too large a second lock-up pressure, and the problem of low lock-up efficiency caused by too small a second lock-up pressure, and balancing driving smoothness and lock-up efficiency through the pressure control of the lock-up clutch.

[0119] From the description of the above embodiments, those skilled in the art can clearly understand that all or part of the steps in the above embodiment methods can be implemented by means of software plus a general hardware platform. Based on such an understanding, the technical solution of the present application can be embodied in the form of a software product. The computer software product can be stored in a storage medium, such as a read-only memory (ROM) / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network communication device such as a router) to execute the methods described in each embodiment or some parts of the embodiments of the present application.

[0120] It should be noted that the embodiments in this specification are described in a progressive manner, and the key points of each embodiment are the differences from other embodiments. The same and similar parts among the embodiments can be referred to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0121] It should also be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0122] The above is only the preferred embodiment of the present application. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present application, or modify it into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of the present application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application without departing from the content of the technical solution of the present application still fall within the scope of protection of the technical solution of the present application.

Claims

1. A method for controlling a locking clutch, characterized in that: The locking clutch is used to realize rigid transmission between the engine and the turbine of the torque converter. The method comprises: When the vehicle meets the locking condition, a first locking pressure, a second locking pressure and a third locking pressure are applied to the locking clutch in sequence, wherein the first locking pressure is used to realize the pressure reversal of the locking clutch, the second locking pressure is determined according to a preset pressure and a latest adaptive pressure, the latest adaptive pressure is an i-th adaptive pressure, and the third locking pressure is used to realize the locking of the locking clutch, wherein i is an integer, and when i is 0, the i-th adaptive pressure is an initial pressure; If it is determined that the lockup clutch satisfies the adaptive activation condition for the (i+1)th time, determining an adaptive pressure increment according to an actual engine speed change rate during a preset time period when the second lockup pressure is applied to the lockup clutch and before the third lockup pressure is applied to the lockup clutch, and a minimum target engine speed change rate; An (i+1)th adaptive pressure is determined according to the (i)th adaptive pressure and the adaptive pressure increment, and the (i+1)th adaptive pressure is used as the latest adaptive pressure.

2. The method according to claim 1, characterized in that If it is determined that the lockup clutch satisfies the adaptive activation condition for the i+1th time, determining the adaptive pressure increment according to the actual engine speed change rate during a preset time period when the second lockup pressure is applied to the lockup clutch and before the third lockup pressure is applied to the lockup clutch, and the minimum target engine speed change rate, comprises: If it is determined that the lockup clutch satisfies the adaptive activation condition for the (i+1)th time, determining a minimum rate of change of the actual engine speed according to the rate of change of the actual engine speed in a preset time period when the second lockup pressure is applied to the lockup clutch and before the third lockup pressure is applied to the lockup clutch; An adaptive pressure increment is determined based on a minimum rate of change of an actual engine speed and a minimum target engine speed rate of change.

3. The method according to claim 2, characterized in that The step of determining the adaptive pressure increment according to the minimum change rate of the actual engine speed and the minimum target engine speed change rate comprises: If the difference between the actual minimum rate of change of the engine speed and the minimum target engine speed rate of change is less than a first threshold, determining an adaptive pressure increment according to the difference and a first calibration coefficient, the first threshold is less than zero, and the adaptive pressure increment is less than zero; If the difference between the actual minimum rate of change of the engine speed and the minimum target engine speed rate of change is greater than a second threshold, determining an adaptive pressure increment according to the difference and a second calibration coefficient, the second threshold is greater than zero, and the adaptive pressure increment is greater than zero; If the difference between the actual minimum rate of change of the engine speed and the minimum target engine speed rate of change is less than or equal to the second threshold and greater than or equal to the first threshold, it is determined that the adaptive pressure increment is zero.

4. The method according to any one of claims 1 to 3, characterized in that: The second locking pressure is determined according to a preset pressure, a pressure threshold and the i-th adaptive pressure, and the pressure threshold is positively correlated with the torque of the engine.

5. The method according to any one of claims 1 to 3, characterized in that: The method further comprises: Obtaining an i-th adaptive pressure corresponding to an actual operating condition parameter of the vehicle, wherein the actual operating condition parameter includes an actual oil temperature and an actual engine torque; Determining a minimum target engine speed change rate corresponding to the actual operating condition parameter; The determining the (i+1)th adaptive pressure according to the i-th adaptive pressure and the adaptive pressure increment comprises: An (i+1)th adaptive pressure corresponding to the actual operating parameter of the vehicle is determined according to the (i)th adaptive pressure corresponding to the actual operating parameter of the vehicle and the adaptive pressure increment.

6. The method according to any one of claims 1 to 3, characterized in that: The third locking pressure includes an open-loop locking pressure of a first stage and a closed-loop locking pressure of a second stage, and the method further includes: determining the open-loop locking pressure according to the second locking pressure and a preset step size; The closed-loop lockup pressure is determined according to the open-loop lockup pressure and a difference between an engine speed and a turbine speed.

7. The method according to any one of claims 1 to 3, characterized in that: The method further comprises: If the absolute value of the difference between the engine speed and the turbine speed is smaller than a preset value, a fourth locking pressure is applied to the lockup clutch, and the fourth locking pressure is greater than the third locking pressure.

8. A control device for a locking clutch, characterized in that: The locking clutch is used to realize the rigid transmission between the engine and the turbine of the torque converter, and the device comprises: a pressure applying unit, used for applying a first locking pressure, a second locking pressure and a third locking pressure to the locking clutch in sequence when the vehicle meets the locking condition, wherein the first locking pressure is used to realize the pressure reversal of the locking clutch, the second locking pressure is determined according to a preset pressure and a latest adaptive pressure, the latest adaptive pressure is an i-th adaptive pressure, and the third locking pressure is used to realize the locking of the locking clutch, wherein i is an integer, and when i is 0, the i-th adaptive pressure is an initial pressure; a pressure increment determination unit, configured to determine an adaptive pressure increment according to an actual engine speed change rate when the second lockup pressure is applied to the lockup clutch and in a preset time period before the third lockup pressure is applied to the lockup clutch, and a minimum target engine speed change rate, if it is determined that the lockup clutch satisfies the adaptive activation condition for the (i+1)th time; The pressure updating unit is used to determine the (i+1)th adaptive pressure according to the (i)th adaptive pressure and the adaptive pressure increment, and the (i+1)th adaptive pressure is used as the latest adaptive pressure.

9. The device according to claim 8, characterized in that The pressure increment determination unit comprises: a minimum change rate determination unit, configured to determine a minimum change rate of the actual speed of the engine according to the actual speed change rate of the engine in a preset time period when the second lockup pressure is applied to the lockup clutch and before the third lockup pressure is applied to the lockup clutch, if it is determined that the lockup clutch satisfies the adaptive activation condition for the i+1th time; The pressure increment determination subunit is used to determine the adaptive pressure increment according to the minimum rate of change of the actual engine speed and the minimum target engine speed rate of change.

10. The device according to claim 9, characterized in that The pressure increment determination subunit is specifically used for: If the difference between the actual minimum rate of change of the engine speed and the minimum target engine speed rate of change is less than a first threshold, determining an adaptive pressure increment according to the difference and a first calibration coefficient, the first threshold is less than zero, and the adaptive pressure increment is less than zero; If the difference between the actual minimum rate of change of the engine speed and the minimum target engine speed rate of change is greater than a second threshold, determining an adaptive pressure increment according to the difference and a second calibration coefficient, the second threshold is greater than zero, and the adaptive pressure increment is greater than zero; If the difference between the actual minimum rate of change of the engine speed and the minimum target engine speed rate of change is less than or equal to the second threshold and greater than or equal to the first threshold, it is determined that the adaptive pressure increment is zero.

Images