Lock-up clutch control method and device, vehicle and medium

Abstract

The invention provides a lock-up clutch control method and device, a vehicle and a medium, the method is applied to the technical field of vehicle control, and the method comprises the steps that target lock-up pressure of a lock-up clutch at the torque zero-crossing moment is obtained; the actual lock-up pressure of the lock-up clutch is controlled to be reduced to the target lock-up pressure before the torque passes zero; and the lock-up clutch is maintained at the target lock-up pressure until the engine completes torque zero passage. According to the method, by finely adjusting the pressure of the lock-up clutch, the problems of power delay, impact, vibration and the like existing when the torque of the engine crosses zero in the related technology are solved.

Description

Technical Field

[0001] The present application relates to the field of vehicle control technology, and more specifically, to a locking clutch control method, device, vehicle and medium in the field of vehicle control. Background Art

[0002] With the continuous development of the automobile market and the improvement of consumer living standards, consumers have increasingly demanding requirements for automobile driving experience. In addition to expecting vehicles to have good power performance and be able to accelerate and travel quickly and smoothly under various working conditions, they also have higher standards for driving comfort, including smoothness during driving, smooth gear shifting, and control of noise and vibration inside the vehicle.

[0003] In order to meet the needs of consumers, relevant technologies limit the output torque gradient under conditions such as torque crossing zero, aiming to reduce the impact and jerk of the vehicle and improve driving comfort by optimizing the power transmission process. However, the limitation of output torque makes it easy for power hysteresis to occur when the engine torque crosses zero, and also causes problems such as impact and vibration to a certain extent. Summary of the invention

[0004] The present application provides a locking clutch control method, device, vehicle and medium, which can solve the problems of power hysteresis, impact and vibration existing in the related technology when the engine torque passes through zero, ensure the power and smoothness when the engine torque passes through zero, and improve the driving comfort and controllability.

[0005] In a first aspect, a locking clutch control method is provided, the method comprising: obtaining a target locking pressure of the locking clutch at the moment when the torque passes through zero; controlling the actual locking pressure of the locking clutch to decrease to the target locking pressure before the torque passes through zero; maintaining the locking clutch at the target locking pressure until the engine completes the torque passing through zero.

[0006] Through the above technical scheme, the embodiment of the present application can reduce the actual locking pressure of the lockup clutch to the target locking pressure before the engine torque passes through zero. The locking pressure is related to the power transmitted by the lockup clutch. The smaller the locking pressure, the less power transmitted by the lockup clutch. Therefore, the locking pressure can be reduced to reduce the power transmitted by the lockup clutch, thereby reducing the impact caused by the power transmission when the engine torque passes through zero. The reduction in the impact can directly reduce the vibration when the engine torque passes through zero, and improve the smoothness when the engine torque passes through zero. At the same time, since the power transmission is small when the engine torque passes through zero, there is no need to limit the output torque gradient, which ensures the power when the engine torque passes through zero, helps to reduce the driver's discomfort during vehicle acceleration, and improves driving comfort.

[0007] In combination with the first aspect, in certain possible implementations, controlling the actual locking pressure of the locking clutch to be reduced to the target locking pressure before the torque passes through zero includes: obtaining a target reduction rate of the locking pressure; and reducing the actual locking pressure to the target locking pressure according to the target reduction rate before the torque passes through zero.

[0008] Through the above technical scheme, the embodiment of the present application achieves precise control of the lock-up clutch pressure change process by obtaining the target reduction rate of the lock-up pressure and reducing the actual lock-up pressure to the target lock-up pressure according to the rate before the torque passes through zero, which enables the lock-up clutch pressure to be accurately adjusted according to the requirement of torque passing through zero, avoiding the randomness and uncertainty of pressure changes. In addition, by setting and following a target reduction rate in advance to gradually reduce the lock-up clutch pressure, sudden impact and vibration can be avoided when the engine torque passes through zero, thereby ensuring the smoothness of power transmission and improving the driving experience.

[0009] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, before controlling the actual locking pressure of the locking clutch to be reduced to the target locking pressure before the torque passes through zero, it also includes: obtaining the engine torque of the hybrid vehicle during the power switching process; if the engine torque is greater than the first torque threshold, then controlling the actual locking pressure of the locking clutch to be reduced to the target locking pressure before the torque passes through zero.

[0010] Through the above technical solution, the embodiment of the present application first obtains the engine torque of the hybrid vehicle during the power switching process before controlling the lockup clutch pressure reduction, and uses the engine torque greater than the first torque threshold as a trigger condition to perform the subsequent pressure reduction operation, indicating that the vehicle needs to be in a working condition for pressure adjustment before the pressure adjustment is performed, avoiding unnecessary control actions, reducing the problems of frustration and impact that may be caused by controlling the lockup clutch too early or too late, thereby improving the response efficiency and reliability of the system. At the same time, when the engine torque is greater than the first torque threshold, it means that the vehicle is in a critical stage where power transmission needs to be controlled. At this time, timely reducing the actual lockup pressure of the lockup clutch to the target lockup pressure can make the engine torque transition more smoothly during the zero-crossing process, reducing the power delay caused by unreasonable torque transmission of the lockup clutch.

[0011] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, before obtaining the engine torque during the power switching process of the hybrid vehicle, it also includes: obtaining the engine torque and the driver's required torque of the hybrid vehicle at the power switching moment; controlling the locking clutch to reduce the actual locking pressure according to the engine torque and the driver's required torque until the actual slip between the engine speed and the turbine speed reaches the target slip.

[0012] Through the above technical scheme, the embodiment of the present application obtains the engine torque and the driver's required torque at the moment of power switching, and controls the lock-up clutch to reduce the actual lock-up pressure accordingly, thereby realizing early intervention of the lock-up clutch pressure. When the power switching is about to occur, the engine torque and the driver's required torque are the key factors that determine the vehicle's power demand and the working state of the power system. By adjusting the lock-up pressure according to these factors in advance, the lock-up clutch can be in a more suitable working state during the power switching process, optimize the power transmission path, avoid poor power transmission or impact due to inappropriate lock-up pressure at the moment of power switching, and improve the response speed and efficiency of the power system. In addition, at the moment of power switching, the lock-up pressure is timely adjusted based on the engine torque and the driver's required torque, so that the engine torque can be transmitted to the wheels more timely and accurately, avoiding the power delay caused by unreasonable lock-up clutch pressure, and reducing the impact caused by the mismatch between the engine and the turbine by accurately controlling the slip.

[0013] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, after maintaining the locking clutch at the target locking pressure, it also includes: if the engine torque is greater than a second torque threshold, determining that the engine has completed the torque zeroing, wherein the second torque threshold is greater than the first torque threshold.

[0014] Through the above technical scheme, the embodiment of the present application sets a second torque threshold value greater than the first torque threshold value to more accurately determine whether the engine has completed the torque zero crossing, which not only improves the adaptability to different driving conditions, but also enhances the reliability and accuracy of the vehicle and avoids misjudgment. In addition, once the engine torque exceeds the second torque threshold value, it can be determined that the engine has completed the torque zero crossing, so that it can transition from the torque zero crossing stage to the normal working state more quickly, reducing unnecessary delays and improving the power response speed.

[0015] In combination with the first aspect and the above-mentioned implementations, in some possible implementations, the power switching process is a process in which the engine torque changes from negative torque to positive torque.

[0016] Through the above technical scheme, the power switching process of the embodiment of the present application is the process of changing the engine torque from negative torque to positive torque. By clarifying the power switching process, each link can be adjusted more specifically and accurately to achieve a smooth transition, thereby meeting the driver's requirements for vehicle power performance and comfort.

[0017] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, after maintaining the lockup clutch at the target lockup pressure until the engine completes the torque crossing zero, it also includes: obtaining the pressure compensation value of the lockup clutch; controlling the lockup clutch to increase the actual lockup pressure according to the pressure compensation value and the engine torque.

[0018] Through the above technical scheme, in the embodiment of the present application, after the engine completes the torque crossing zero, the engine enters the normal positive torque output stage. At this time, appropriate locking pressure is required to ensure that power is efficiently transmitted to the wheels. Through the calculation and application of the pressure compensation value, the locking clutch pressure can be accurately adjusted according to the actual torque of the engine, so that the locking clutch can better transmit the engine torque, reduce power loss, and improve the transmission efficiency of the power system. At the same time, the locking clutch pressure compensation value is dynamically adjusted according to the change of the engine torque, so that the working state of the locking clutch can always match the engine working condition, thereby optimizing driving comfort. In addition, during the pressure compensation process after the engine torque passes zero, if the pressure is improperly increased, it may cause excessive wear to the locking clutch plate, or produce excessive impact loads on components such as the transmission. By accurately calculating the pressure compensation value and controlling it according to the engine torque, it is possible to avoid the situation where the locking clutch pressure is too high or too low, and reduce the risk of wear and damage between components.

[0019] In a second aspect, a locking clutch control device is provided, which includes: an acquisition module for acquiring a target locking pressure of the locking clutch at the moment when the torque passes through zero; a control module for controlling the actual locking pressure of the locking clutch to be reduced to the target locking pressure before the torque passes through zero; and a maintaining module for maintaining the locking clutch at the target locking pressure until the engine completes the torque passing through zero.

[0020] In a third aspect, a hybrid vehicle is provided, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement any one of the above-mentioned locking clutch control methods.

[0021] In a fourth aspect, a computer-readable storage medium is provided, which stores a computer program code. When the computer program code runs on a computer, the computer executes the locking clutch control method in the above-mentioned first aspect or any possible implementation of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic flow chart of a locking clutch control method provided according to an embodiment of the present application;

[0023] Figure 2 is a flow chart of a locking clutch control method provided according to an embodiment of the present application;

[0024] Figure 3 is a working principle diagram of the lock-up clutch pressure pre-control provided according to an embodiment of the present application;

[0025] Figure 4This is a working principle diagram of the TP3 stage control of the lock-up clutch provided according to an embodiment of the present application;

[0026] Figure 5 is a working principle diagram of the lock-up clutch pressure recovery control phase according to an embodiment of the present application;

[0027] Figure 6 is a schematic structural diagram of a locking clutch control device provided according to an embodiment of the present application;

[0028] Figure 7 It is a schematic diagram of the structure of a hybrid vehicle provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0029] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0030] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0031] The power architecture of hybrid vehicles is composed of P2 motor and engine as power output sources. When the engine torque and P2 motor torque are negative torque during coasting; when the accelerator is pressed, when the output torque changes from negative value to positive value, or when the engine speed crosses the input shaft speed from the bottom of the turbine to the top of the turbine, the HCU or VCU limits the output torque gradient and slowly passes through the zero torque point within a certain torque range until the engine torque is greater than a certain torque value or the input shaft speed passes through the turbine to transition the torque from negative torque to positive torque. In this way, the acceleration of the vehicle is affected to a certain extent in terms of power performance, giving the driver a certain sense of deceleration.

[0032] When the vehicle is coasting or the accelerator is suddenly pressed to activate Tipin, the engine goes from a fuel-cut state to a fuel-resuming state, the torque changes from negative torque to positive torque, and the input shaft speed crosses the turbine speed. The TCU only responds to the request status of the HCU or VCU for the lockup clutch. Due to the complex working conditions, the HCU or VCU cannot accurately control the impact of the torque repeatedly crossing zero on the drivability, resulting in drivability problems. For example, when the accelerator is pressed again during coasting or when the accelerator is pressed again after braking, the output torque changes from negative torque to positive torque, and the lockup clutch is in a locked state when the input shaft speed crosses the turbine speed, resulting in impact and other drivability problems.

[0033] Before explaining the locking clutch control method provided in the embodiment of the present application, the control signal involved in the embodiment of the present application is first explained.

[0034] The control signals of the embodiment of the present application include: input speed: the speed of the transmission input end, that is, the engine or motor speed; input shaft speed: turbine speed; target slip speed: the slip between the turbine and engine speeds; locking clutch state: the main state of the locking clutch, such as SLIP, closed, TP1, TP3, etc.; throttle opening: the opening of the throttle pedal; torque gradient: the torque gradient required by the driver; input torque: engine torque; clutch pressure: the minimum value of the locking clutch.

[0035] Figure 1 It is a schematic flow chart of a locking clutch control method provided in an embodiment of the present application.

[0036] For example, Figure 1 As shown, the locking clutch control method includes:

[0037] In step S101 , a target lockup pressure of the lockup clutch at the moment when the torque passes through zero is acquired.

[0038] Among them, the lock-up clutch is an important component in the automatic transmission, located between the engine and the transmission. Its main function is to directly connect the engine to the transmission under certain conditions, thereby reducing the slip loss in the torque converter and improving fuel economy and power transmission efficiency. The torque zero-crossing moment refers to the moment when the torque value is exactly zero during the process of the engine torque changing from negative torque to positive torque. The target lock-up pressure is an ideal pressure value that the lock-up clutch should reach at the moment of torque zero-crossing. It can be calculated and calibrated based on a series of factors. The purpose is to ensure that at this critical moment of torque zero-crossing, the lock-up clutch can work at an appropriate pressure, thereby achieving smooth power switching and avoiding driving problems such as impact and shaking.

[0039] It is understandable that the embodiment of the present application provides an accurate basis for the entire control process by obtaining the target locking pressure of the locking clutch at the moment when the torque passes through zero, clarifies the control direction of the locking clutch pressure, and improves the accuracy and reliability of the power system control. At the same time, it can optimize the torque transition smoothness, avoid vehicle shaking or impact, make acceleration smoother and more natural, and improve the driving experience. In addition, the embodiment of the present application can also speed up the response speed of the power system under the torque zero condition, reduce power hysteresis, and ensure acceleration requirements.

[0040] In step S102 , the actual lockup pressure of the lockup clutch is controlled to be reduced to the target lockup pressure before the torque crosses zero.

[0041] The actual lockup pressure refers to the actual pressure value of the lockup clutch during actual operation, which reflects the actual working state of the lockup clutch under different working conditions.

[0042] It can be understood that in the embodiment of the present application, when the engine torque changes from negative to positive, the pressure of the locking clutch is gradually reduced, so that sudden impact and vibration can be avoided. This progressive pressure adjustment ensures the smoothness of power transmission and significantly improves driving smoothness.

[0043] In an embodiment of the present application, controlling the actual lockup pressure of the lockup clutch to be reduced to the target lockup pressure before the torque passes through zero includes: obtaining a target reduction rate of the lockup pressure; and reducing the actual lockup pressure to the target lockup pressure according to the target reduction rate before the torque passes through zero.

[0044] The target reduction rate refers to a pre-set pressure reduction speed before the torque passes through zero, in order to smoothly and reasonably reduce the actual lockup pressure of the lockup clutch to the target lockup pressure. The target reduction rate specifies the value of the lockup pressure that should be reduced per unit time, and is a parameter that controls the pressure change process of the lockup clutch.

[0045] It can be understood that the embodiment of the present application can achieve precise control of the lock-up clutch pressure change process by obtaining the target reduction rate of the lock-up pressure and reducing the actual lock-up pressure to the target lock-up pressure according to the rate before the torque passes through zero, which enables the lock-up clutch pressure to be accurately adjusted according to the requirement of the torque passing through zero, avoiding the randomness and uncertainty of the pressure change. In addition, by setting and following a target reduction rate in advance to gradually reduce the lock-up clutch pressure, sudden impact and vibration can be avoided when the engine torque passes through zero, thereby ensuring the smoothness of power transmission and improving the driving experience.

[0046] In an embodiment of the present application, before controlling the actual locking pressure of the locking clutch to be reduced to the target locking pressure before the torque passes through zero, it also includes: obtaining the engine torque of the hybrid vehicle during the power switching process; if the engine torque is greater than the first torque threshold, then controlling the actual locking pressure of the locking clutch to be reduced to the target locking pressure before the torque passes through zero.

[0047] Among them, the engine torque is the key basis for judging the timing and strategy of the lock-up clutch pressure control during the vehicle power switching process. Its size and change trend directly affect the working state and pressure adjustment demand of the lock-up clutch. By obtaining the engine torque in real time, the control system can accurately understand the current power demand of the vehicle and the working state of the engine, so as to adjust the actual lock-up pressure of the lock-up clutch according to the predetermined control strategy to achieve smooth power switching and good driving performance; the first torque threshold is the trigger condition for controlling the lock-up clutch pressure adjustment. When it is detected that the engine torque is greater than the first torque threshold, the control system starts a series of operations, including controlling the actual lock-up pressure of the lock-up clutch to be reduced to the target lock-up pressure before the torque passes through zero. By setting the first torque threshold, the pressure control of the lock-up clutch can be made more accurate and timely, and effective pressure adjustment is only performed when the actual working conditions of the vehicle require it, avoiding unnecessary control actions, improving the response efficiency and control accuracy of the system, and also helping to protect the power system components, extend their service life, and improve the reliability and stability of the entire hybrid vehicle.

[0048] It is understandable that the embodiment of the present application first obtains the engine torque of the hybrid vehicle during the power switching process before controlling the lockup clutch pressure reduction, and uses the engine torque greater than the first torque threshold as a trigger condition to perform the subsequent pressure reduction operation, indicating that the vehicle needs to be in a working condition for pressure adjustment before the pressure adjustment is performed, avoiding unnecessary control actions, reducing the problems such as setbacks and impacts that may be caused by controlling the lockup clutch too early or too late, thereby improving the response efficiency and reliability of the system. At the same time, when the engine torque is greater than the first torque threshold, it means that the vehicle is in a critical stage where power transmission needs to be controlled. At this time, timely reducing the actual lockup pressure of the lockup clutch to the target lockup pressure can make the engine torque transition more smoothly during the zero-crossing process, reducing the power delay caused by unreasonable torque transmission of the lockup clutch.

[0049] In an embodiment of the present application, before obtaining the engine torque during the power switching process of the hybrid vehicle, it also includes: obtaining the engine torque and the driver's required torque of the hybrid vehicle at the power switching moment; braking the locking clutch to reduce the actual locking pressure according to the engine torque and the driver's required torque until the actual slip between the engine speed and the turbine speed reaches the target slip.

[0050] Among them, driver demand torque refers to the expectation of torque output conveyed by the driver to the vehicle power system by operating the accelerator pedal. It reflects the driver's subjective willingness for the vehicle's driving states such as acceleration, deceleration or maintaining speed. When the driver steps on the accelerator pedal, the change in throttle opening corresponds to different driver demand torque values. The larger the throttle opening, it usually means that the driver expects to obtain greater torque to achieve faster acceleration or overcome greater driving resistance. Conversely, releasing the accelerator pedal means that the driver's demand torque decreases, which may be the desire for the vehicle to decelerate or glide; target slip refers to the expected difference between the pre-set engine speed and the turbine speed in the power system of a hybrid vehicle, which is used to accurately control the working state of the lock-up clutch.

[0051] It can be understood that the embodiment of the present application achieves early intervention in the lockup clutch pressure by obtaining the engine torque and the driver's required torque at the moment of power switching, and controlling the lockup clutch accordingly to reduce the actual lockup pressure. When the power switching is about to occur, the engine torque and the driver's required torque are the key factors that determine the vehicle's power demand and the working state of the power system. By adjusting the lockup pressure according to these factors in advance, the lockup clutch can be in a more appropriate working state during the power switching process, optimizing the power transmission path, avoiding poor power transmission or impact due to inappropriate lockup pressure at the moment of power switching, and improving the response speed and efficiency of the power system. In addition, at the moment of power switching, the lockup pressure is adjusted in time based on the engine torque and the driver's required torque, so that the engine torque can be transmitted to the wheels more promptly and accurately, avoiding the power delay caused by unreasonable lockup clutch pressure, and reducing the impact caused by the mismatch between the engine and the turbine by accurately controlling the slip.

[0052] In the embodiment of the present application, the power switching process is the process in which the engine torque changes from negative torque to positive torque.

[0053] It can be understood that the power switching process in the embodiment of the present application is the process of changing the engine torque from negative torque to positive torque. By clarifying the power switching process, each link can be adjusted more specifically and accurately to achieve a smooth transition and meet the driver's requirements for vehicle power performance and comfort.

[0054] In step S103 , the lockup clutch is maintained at the target lockup pressure until the engine completes the torque zero crossing.

[0055] It can be understood that in the embodiment of the present application, during the process of engine torque crossing zero, maintaining the lockup clutch at the target lockup pressure can ensure a smooth transition of power transmission between the engine and the transmission. When the engine torque changes from negative to positive, if the lockup clutch pressure is unstable, it may cause fluctuations in power transmission and the vehicle will feel jerky. The target lockup pressure is accurately calculated and calibrated. Under this pressure, the lockup clutch can connect the engine and transmission in a suitable state, making the increase and decrease of power more linear, effectively avoiding the impact and jitter caused by torque reversing, and providing the driver with a more comfortable driving experience.

[0056] In the embodiment of the present application, after maintaining the lockup clutch at the target lockup pressure, it also includes: if the engine torque is greater than a second torque threshold, determining that the engine has completed torque zeroing, wherein the second torque threshold is greater than the first torque threshold.

[0057] The second torque threshold is a specific torque value used to clearly determine the engine's torque zero crossing during the hybrid vehicle power switching control process. It is a pre-set fixed value greater than the first torque threshold, and its specific value is determined based on the characteristics of the vehicle power system, engine performance, and a large amount of test and actual operation data.

[0058] It can be understood that by setting a second torque threshold that is greater than the first torque threshold in the embodiment of the present application, the system can more accurately determine whether the engine has completed the torque zero crossing, which not only improves the control system's adaptability to different driving conditions, but also enhances the system's reliability and accuracy and avoids misjudgment. In addition, once the engine torque exceeds the second torque threshold, the system can determine that the engine has completed the torque zero crossing, so that the system can transition from the torque zero crossing stage to the normal working state more quickly, reducing unnecessary delays and improving the power response speed.

[0059] In an embodiment of the present application, after maintaining the lockup clutch at the target lockup pressure until the engine completes the torque crossing zero, it also includes: obtaining a pressure compensation value of the lockup clutch; and controlling the lockup clutch to increase the actual lockup pressure according to the pressure compensation value and the engine torque.

[0060] Among them, the pressure compensation value is the locking pressure value that is additionally increased or adjusted after the engine completes the torque zeroing in order to optimize the working state of the locking clutch so that it can better adapt to the subsequent vehicle operation needs. It is a dynamic parameter calculated based on multiple factors such as the vehicle's current operating conditions, engine torque size, and overall performance requirements of the power system.

[0061] It is understandable that in the embodiment of the present application, after the engine completes the torque zeroing, the engine enters the normal positive torque output stage, at which time a suitable locking pressure is required to ensure that the power is efficiently transmitted to the wheels. By calculating and applying the pressure compensation value, the locking clutch pressure can be accurately adjusted according to the actual torque of the engine, so that the locking clutch can better transmit the engine torque, reduce power loss, and improve the transmission efficiency of the power system. At the same time, the locking clutch pressure compensation value is dynamically adjusted according to the engine torque change, so that the working state of the locking clutch can always match the engine working condition, thereby optimizing driving comfort. In addition, during the pressure compensation process after the engine torque passes zero, if the pressure is improperly increased, it may cause excessive wear to the locking clutch plate, or generate excessive impact loads on components such as the transmission. By accurately calculating the pressure compensation value and controlling it according to the engine torque, it is possible to avoid the situation where the locking clutch pressure is too high or too low, and reduce the risk of wear and damage between components.

[0062] The locking clutch control method proposed in the embodiment of the present application provides a precise direction for the control process by obtaining the target locking pressure at the moment when the torque passes through zero, improves the control accuracy and reliability of the power system, optimizes the torque transition smoothness, avoids jitter shock, makes acceleration smooth and natural, improves the driving experience, speeds up the response speed, and reduces power lag; gradually reduces the locking clutch pressure during the positive and negative transitions of the engine torque to ensure smooth power transmission and improve driving smoothness; controls the pressure change according to the target reduction rate to achieve precise adjustment, avoid randomness, and ensure smooth power transmission; uses the engine torque greater than the first torque threshold as a trigger to adjust the pressure to avoid unnecessary control, improve response efficiency and reliability, make the torque zero transition smoother, and reduce power delay; according to the power switch The engine and driver demand torque at all times to intervene in the lock-up pressure in advance, optimize the power transmission path, improve the response speed and efficiency, avoid power delay and impact, and accurately control the slip; clarify the power switching process, and make targeted and precise adjustments to achieve a smooth transition to meet the power performance and comfort requirements; the engine torque passes through zero to maintain the target lock-up pressure, ensure linear changes in power transmission, avoid shocks and setbacks, and provide a comfortable driving experience; set the second torque threshold to accurately judge the completion of the torque zero crossing, improve the system adaptability, reliability and accuracy, reduce delays and improve the power response speed; after the engine completes the torque zero crossing, the lock-up pressure is accurately adjusted through the pressure compensation value to improve the transmission efficiency, so that the working state of the lock-up clutch matches the engine operating conditions to optimize comfort and avoid excessive wear and damage risks of components.

[0063] The following will describe the locking clutch control method through a specific embodiment. The flow chart of the control method is as follows: Figure 2 As shown, the details are as follows:

[0064] 1. Lock-up clutch pressure pre-control

[0065] When the vehicle power state is negative torque, negative slip, and the lockup clutch state is in the speed PID control state, when the driver suddenly steps on the pedal, the engine torque starts to change from negative torque to positive torque, activating the lockup clutch pressure pre-control stage. Then the lockup clutch will compensate the lockup clutch pressure according to the driver's required torque gradient and the actual engine torque change, and control the lockup clutch to establish slip by calibrating the pressure compensation value to avoid torque zero when the power is switched, and the lockup clutch has no slip to cause impact. Its working principle diagram is as follows Figure 3 shown.

[0066] 2. Locking clutch TP3 stage control

[0067] When it is recognized that the driver is performing a Tipin action and the engine does not intervene, the torque is greater than or equal to a certain torque value -30Nm (calibratable value), and after a certain delay time (calibratable value), the locking clutch is in a positive torque and enters a transition state TP3.

[0068] When the lock-up clutch is in the TP3 control stage, the engine power switches from negative torque to positive torque or the engine speed crosses the input shaft speed from the bottom of the turbine to the top of the turbine, the torque passes through zero torque, and the lock-up clutch pressure transitions to the target pressure. The purpose is that when the engine torque passes through zero, the lock-up clutch transmits the minimum torque to avoid impact when the power switches from negative to positive torque. The working principle diagram is as follows Figure 4 shown.

[0069] 3. Lock-up clutch pressure recovery control

[0070] When the engine torque is greater than a certain value of 45Nm (calibratable value), the control state of the lock-up clutch exits TP3 and enters the speed PID state after filtering through TP1. In the TP1 stage, it transitions to the target pressure according to the filtering coefficient.

[0071] When exiting the TP3 state and transitioning to the speed PID state through TP1, the engine torque has become positive torque and drives the vehicle to provide positive acceleration. At this time, the lock-up clutch pressure increases from the basic pressure to the target pressure. When the engine torque is restored, due to the hysteresis of the lock-up clutch hydraulic system, the lock-up clutch pressure follows the response slowly, resulting in lock-up slip friction. Therefore, when exiting the TP3 state, the lock-up clutch pressure compensation is added to control the lock-up clutch slip speed.

[0072] After entering the speed PID, the lock-up clutch enters PI control. To avoid sudden changes in the lock-up clutch PI calculation pressure, the TIPIN target slip is set to enter closed-loop control. The purpose is to avoid synchronous shock caused by large slip value and sudden changes in the lock-up pressure dragging the engine speed when calculating the lock-up pressure. The working principle diagram is as follows Figure 5 shown.

[0073] Among them, TIPIN refers to the condition where the accelerator pedal opening suddenly increases but does not cause the transmission to downshift; the SPIDLE of the lock-up clutch state is the lock-up clutch slip control state; the lock-up clutch state TP3 is the lock-up clutch open state, and the pressure is maintained at the minimum pressure value; the lock-up clutch state TP1 is the lock-up clutch pressure filter transition state.

[0074] The implementation steps of the control method are as follows:

[0075] During normal driving, the driver stabilizes the accelerator pedal, and the engine speed and turbine speed maintain a stable sliding speed range. When the driver releases the accelerator or reduces the accelerator pedal, the vehicle's driving state changes from driving to dragging. At this time, the engine torque is negative torque, and the engine speed is below the turbine. If the driver changes his intention to accelerate at this time, the engine torque will change from negative torque to positive torque, and the engine speed must pass through the turbine speed to accelerate. At this time, in order to avoid drivability problems, it is necessary to control the lockup clutch to reduce the transmission torque to ensure that when the engine torque changes from negative to positive torque or the input shaft speed passes under the turbine, there is no impact and vibration caused by excessive torque on the lockup clutch. This working condition is related to the driver's required torque gradient, the actual engine torque, and the throttle opening.

[0076] If the driver suddenly accelerates during coasting, in order to avoid the impact of torque reversal or input speed passing through the turbine on acceleration, when the driver steps on the accelerator pedal, the lock-up clutch will control the lock-up clutch pressure based on the current driver-demand torque gradient and the change in actual engine torque, thereby reducing the lock-up pressure of the lock-up clutch and allowing the engine speed and turbine speed to produce a controllable stable slip of 30rpm (calibratable value), thereby ensuring stable control of the system when the engine torque is reversing or the input shaft speed passes through the turbine.

[0077] When the input torque recovers to be greater than a certain torque value -30Nm (calibratable value), the lock-up clutch TP3 control is entered, and the lock-up clutch pressure will be reduced to the minimum pressure value (calibratable value) to ensure that when the input torque passes through zero torque from negative torque, the lock-up clutch maintains the minimum pressure, reducing the torque transmitted by the lock-up clutch to avoid impact when crossing zero torque.

[0078] When the input torque passes through zero and is greater than a certain torque value of 45Nm (calibratable value), it is judged that the zero crossing is completed, and the TP3 control lockup clutch is exited to restore the pressure to follow the input torque for control. The vehicle power switching is completed, and the engine torque becomes positive torque, and the pressure compensation of the lockup clutch is increased to prevent excessive TC slip due to the failure of the lockup clutch pressure to follow, and shock and jitter when locked.

[0079] In summary, the locking clutch control method proposed in the embodiment of the present application improves driving comfort, effectively reduces the impact and vibration caused by locking clutch problems during driving, optimizes acceleration smoothness, and makes the driving experience smoother and more comfortable; in terms of improving the reliability and efficiency of the power system, it protects the power system components, reduces impact loads, and extends the life of components, while improving power transmission efficiency and reducing power loss; in terms of enhancing the adaptability and response speed of the system, it can adapt to a variety of complex driving conditions, adjust the locking clutch pressure in real time according to different factors, and also speed up the system response speed, reduce power hysteresis, and improve the vehicle's controllability and safety, thereby comprehensively improving the performance of the vehicle's power system.

[0080] Figure 6 It is a structural schematic diagram of a locking clutch control device provided in an embodiment of the present application.

[0081] For example, Figure 6 As shown, the device 600 may include: an acquisition module 610 , a control module 620 and a maintenance module 630 .

[0082] Among them, the acquisition module 610 is used to obtain the target locking pressure of the lockup clutch at the moment when the torque passes through zero; the control module 620 is used to control the actual locking pressure of the lockup clutch to be reduced to the target locking pressure before the torque passes through zero; the maintenance module 630 is used to maintain the lockup clutch at the target locking pressure until the engine completes the torque passing through zero.

[0083] It should be noted that the explanation of the aforementioned locking clutch control method embodiment is also applicable to the locking clutch control device of this embodiment, and will not be repeated here.

[0084] In summary, in the locking clutch control device proposed in the embodiment of the present application, the acquisition module accurately acquires the target locking pressure at the moment when the torque passes through zero, thereby laying a precise foundation for control and improving the accuracy and reliability of power system control; the control module accurately reduces the actual locking pressure to the target value before the torque passes through zero, thereby realizing progressive pressure adjustment, avoiding impact vibration, ensuring smooth power transmission, and improving driving smoothness; the maintenance module stably maintains the target locking pressure during the period when the engine torque passes through zero, thereby ensuring linear changes in power transmission, preventing setbacks, and optimizing driving experience. At the same time, the device as a whole coordinates and optimizes the system response speed, reduces power hysteresis, and can also enhance system reliability, reduce the risk of component wear, extend service life, and improve the system's adaptability to different driving conditions and operating states, so that the vehicle can maintain good performance and stability under various complex situations.

[0085] Figure 7 : is a schematic diagram of the structure of a hybrid vehicle provided by an embodiment of the present application. The vehicle may include:

[0086] A memory 701 , a processor 702 , and a computer program stored in the memory 701 and executable on the processor 702 .

[0087] When the processor 702 executes the program, the locking clutch control method provided in the above embodiment is implemented.

[0088] Furthermore, the vehicle also includes:

[0089] The communication interface 703 is used for communication between the memory 701 and the processor 702 .

[0090] The memory 701 is used to store computer programs that can be executed on the processor 702 .

[0091] The memory 701 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0092] If the memory 701, the processor 702 and the communication interface 703 are implemented independently, the communication interface 703, the memory 701 and the processor 702 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 7 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0093] Optionally, in a specific implementation, if the memory 701, the processor 702 and the communication interface 703 are integrated on a chip, the memory 701, the processor 702 and the communication interface 703 can communicate with each other through an internal interface.

[0094] The processor 702 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0095] This embodiment also provides a computer-readable storage medium, in which a computer program code is stored. When the computer program code is run on a computer, the computer executes the above-mentioned related method steps to implement the locking clutch control method provided in the above-mentioned embodiment.

[0096] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0097] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0098] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A locking clutch control method, characterized in that: The method comprises: Obtaining a target locking pressure of the locking clutch at the moment when the torque passes through zero; Controlling the actual lockup pressure of the lockup clutch to decrease to the target lockup pressure before the torque passes through zero; The lockup clutch is maintained at the target lockup pressure until the engine completes torque zero crossing.

2. The lock-up clutch control method according to claim 1, characterized in that: The controlling the actual lockup pressure of the lockup clutch to decrease to the target lockup pressure before the torque passes through zero includes: obtaining a target reduction rate of the lockup pressure; Before the torque passes through zero, the actual lockup pressure is reduced to the target lockup pressure at the target reduction rate.

3. The lockup clutch control method according to claim 1 or 2, characterized in that: Before controlling the actual lockup pressure of the lockup clutch to decrease to the target lockup pressure before the torque passes through zero, it also includes: Obtaining the engine torque of the hybrid vehicle during power switching; If the engine torque is greater than the first torque threshold, the actual lockup pressure of the lockup clutch is controlled to decrease to the target lockup pressure before the torque passes through zero.

4. The lockup clutch control method according to claim 3, characterized in that: Before obtaining the engine torque during the power switching process of the hybrid vehicle, it also includes: Obtaining the engine torque and the driver's required torque of the hybrid vehicle at the power switching moment; The lockup clutch is controlled to reduce an actual lockup pressure according to the engine torque and the driver demand torque until an actual slip between an engine speed and a turbine speed reaches a target slip.

5. The lock-up clutch control method according to claim 3, characterized in that: After maintaining the lockup clutch at the target lockup pressure, the method further includes: If the engine torque is greater than a second torque threshold, it is determined that the engine completes the torque zero crossing, wherein the second torque threshold is greater than the first torque threshold.

6. The lock-up clutch control method according to claim 3, characterized in that: The power switching process is a process in which the engine torque changes from negative torque to positive torque.

7. The lock-up clutch control method according to claim 1, characterized in that: The method further comprises: maintaining the lockup clutch at the target lockup pressure until the engine completes the torque zero crossing; obtaining a pressure compensation value of the locking clutch; The lockup clutch is controlled to increase actual lockup pressure according to the pressure compensation value and the engine torque.

8. A locking clutch control device, characterized in that: The device comprises: An acquisition module, used for acquiring a target locking pressure of the locking clutch at the moment when the torque passes through zero; A control module, used for controlling the actual lockup pressure of the lockup clutch to decrease to a target lockup pressure before the torque passes through zero; The maintaining module is used to maintain the lockup clutch at the target lockup pressure until the engine completes the torque zero crossing.

9. A hybrid vehicle, characterized in that: The vehicle comprises: a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor executes the program to implement the locking clutch control method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed, the locking clutch control method according to any one of claims 1 to 7 is implemented.

Images