Clutch control method and vehicle

Abstract

The invention provides a clutch control method and a vehicle, and belongs to the technical field of power control of vehicles. According to the technical scheme provided by the embodiment of the invention, in response to the fact that the automatic start-stop function of the engine is in the activated state, under the condition that the obtained start-stop state is the target state, the relevant parameters of the target pressure control stage corresponding to the target state are obtained; therefore, the target clutch pressure is determined on the basis of the relevant parameters in the target pressure control stage of the multiple continuous pressure stages, the clutch is controlled on the basis of the target clutch pressure, the drivability problem occurring in the slip frequency control process is avoided, the vehicle driving experience is comprehensively improved, meanwhile, the clutch is free of sliding friction in the starting process, and the service life of the vehicle is prolonged. The service life of related parts can be prolonged; moreover, clutch pressure can be quickly provided in different pressure control stages, the input torque of an engine does not need to be limited in the starting process, and the starting dynamic property of the whole vehicle can be improved.

Description

Technical Field

[0001] This application relates to the field of vehicle power control technology, and more specifically, to a clutch control method and a vehicle in the field of vehicle power control technology. Background Technology

[0002] With the development of vehicle technology, more and more vehicles have automatic start-stop function. Automatic start-stop function is a technology that automatically stops and starts the engine. Its purpose is to stop the engine when the vehicle is stopped and waiting in place, thereby reducing unnecessary fuel consumption and saving fuel.

[0003] In related technologies, slip control is used during engine start-up via automatic start-stop. During slip control, clutch pressure is increased to gradually reduce the clutch slip below a calibrated value, allowing the vehicle to restart. However, considering the clutch hydraulic response delay, slip control typically limits engine output torque, resulting in a delayed start-up power response. This leads to problems such as low overall vehicle power and a poor driving experience.

[0004] Therefore, how to provide sufficient power to the vehicle while the automatic start-stop function is activated is a hot research topic. Summary of the Invention

[0005] This application provides a clutch control method and a vehicle, which can provide sufficient power to the vehicle when the automatic start-stop function is activated. The technical solution is as follows: Firstly, a method for controlling a clutch is provided, the method comprising: In response to the engine's automatic start-stop function being activated, the start-stop status of the engine is obtained; When the start-stop state is the target state, the relevant parameters of the target pressure control stage corresponding to the target state are obtained. The target state is located after the start state and before the operation state. The target pressure control stage includes multiple consecutive pressure stages. The target clutch pressure is determined based on the relevant parameters, and the clutch is controlled based on the target clutch pressure. The upward trend of the target clutch pressure corresponding to the multiple consecutive pressure stages is different.

[0006] In this implementation, in response to the engine's automatic start-stop function being activated, and given that the acquired start-stop state is the target state, relevant parameters for the target pressure control stage corresponding to the target state are acquired. Based on these parameters, the target clutch pressure is determined in multiple consecutive target pressure control stages. The clutch is then controlled based on this target clutch pressure. This segmented pressure control method replaces the slip control process, thus avoiding drivability issues that arise during slip control and comprehensively improving the vehicle's driving experience. Furthermore, clutch pressure can be quickly provided in different pressure control stages, eliminating the need to limit engine input torque during start-up and improving overall vehicle starting power. Simultaneously, segmented continuous pressure control enables zero-slip control of the gear clutch, reducing clutch slippage during start-up, extending the service life of related components, and improving the smoothness and driving comfort during automatic start-stop restart.

[0007] In conjunction with the first aspect, in some possible implementations, the plurality of consecutive pressure stages include a first pressure stage, a second pressure stage, and a third pressure stage. The acquisition of relevant parameters for the target pressure control stage corresponding to the target state includes: when the target pressure control stage is the first pressure stage, acquiring a target correction coefficient, a first clutch critical pressure, a first engine torque, a first engine speed, and a first transmission speed, wherein the first pressure stage is used to increase the clutch pressure based on a target calibration time; when the target pressure control stage is the second pressure stage, acquiring a second engine torque, a second engine speed, and a second transmission speed, wherein the second pressure stage is used to increase the clutch pressure based on the target pressure; and when the target pressure control stage is the third pressure stage, acquiring a third engine torque, a third engine speed, a third transmission speed, and a clutch torque, wherein the third pressure stage is used to control the clutch engagement so that the engine torque output is transmitted to the transmission.

[0008] In this implementation, different relevant parameters are acquired at different stages of multiple consecutive pressure phases, thereby enabling the targeted determination of the clutch pressure at different pressure phases. The clutch pressure control is dynamically adjusted based on the relevant parameters acquired in real time, so that the clutch pressure control can not only respond quickly to driving intentions, but also adapt to changes in operating conditions, ensuring the continuity and stability of power transmission.

[0009] In combination with the first aspect and the above implementation methods, in some possible implementation methods, determining the target clutch pressure based on the relevant parameters includes: when the target pressure control stage is the first pressure stage, determining a first intermediate pressure based on the first engine torque, the first engine speed, and the first transmission speed; correcting the first intermediate pressure based on the target correction coefficient to obtain a first compensation pressure; and using the sum of the first compensation pressure and the first clutch critical pressure as the target clutch pressure.

[0010] In this implementation, when the target pressure control stage is the first pressure stage, the first intermediate pressure is determined by the first engine torque, the first engine speed, and the first transmission speed. Then, the first intermediate pressure is corrected by the target correction coefficient to obtain the first compensation pressure. The sum of the first compensation pressure and the first clutch critical pressure is then used as the target clutch pressure. This allows the clutch pressure to increase steadily based on the clutch critical pressure, enhancing the response speed and smoothness of pressure control, and improving driving comfort and transmission system coordination.

[0011] In combination with the first aspect and the above implementation methods, in some possible implementation methods, determining the target clutch pressure based on the relevant parameters includes: when the target pressure control stage is the second pressure stage, determining a first ascending gradient pressure and a pre-controlled target pressure based on the second engine torque, the second engine speed, and the second transmission speed; and using the first ascending gradient pressure and the pre-controlled target pressure as the target clutch pressure.

[0012] In this implementation, when the target pressure control stage is the second pressure stage, the first ascending gradient pressure and the pre-controlled target pressure are determined by the second engine torque, the second engine speed, and the second transmission speed. Then, the clutch pressure is increased to the pre-controlled target pressure using the first ascending gradient pressure. This allows the clutch pressure to be increased according to the expected clutch pressure in the second pressure stage, thus optimizing the transition capability of the power system from restart to smooth operation during the automatic start-stop process.

[0013] In combination with the first aspect and the above implementation, in some possible implementations, the method further includes: in response to the target pressure control stage being the first pressure stage, obtaining a target control time; and if the target control time is greater than or equal to the target calibration time, switching the target pressure control stage from the first pressure stage to the second pressure stage.

[0014] In this implementation, the target control time is acquired when the target pressure control stage is the first pressure stage. Then, if the target control time is greater than or equal to the target calibration time, the target pressure control stage is switched from the first pressure stage to the second pressure stage. This not only prevents insufficient pressure and unstable power engagement that may result from switching to the second pressure stage too early, but also avoids response delays caused by excessive time consumption in the first pressure stage, thus achieving a stable transition between control stages.

[0015] In combination with the first aspect and the above implementation methods, in some possible implementation methods, determining the target clutch pressure based on the relevant parameters includes: when the target pressure control stage is the third pressure stage, determining the clutch torque-pressure characteristic pressure based on the clutch torque; determining the second ascending gradient pressure based on the third engine torque, the third engine speed, and the third transmission speed; correcting the second ascending gradient pressure based on the clutch torque-pressure characteristic pressure to obtain a second intermediate pressure; and using the second intermediate pressure as the target clutch pressure.

[0016] In this implementation, when the target pressure control stage is the third pressure stage, the clutch torque-pressure characteristic pressure is determined using the clutch torque, and the second ascending gradient pressure is determined using the third engine torque, the third engine speed, and the third transmission speed. The second intermediate pressure obtained by correcting the second ascending gradient pressure using the clutch torque-pressure characteristic pressure is used as the target clutch pressure. This allows for the constraint of the real-time determined second ascending gradient pressure in the third pressure stage, improving the accuracy of the target clutch pressure and ensuring the smoothness of power boost.

[0017] In conjunction with the first aspect and the above implementation methods, in some possible implementation methods, the method further includes: when the start-stop state is the start state, acquiring the fourth engine speed, the fourth engine torque, and the transmission oil temperature; determining a third intermediate pressure based on the fourth engine torque and the transmission oil temperature, and determining a second compensation pressure based on the fourth engine speed and the transmission oil temperature; using the sum of the third intermediate pressure and the second compensation pressure as the clutch control pressure; and controlling the clutch based on the clutch control pressure.

[0018] In this implementation, when the start-stop state is the start state, the third intermediate pressure is determined by the fourth engine torque and the transmission oil temperature, and the second compensation pressure is determined by the fourth engine speed and the transmission oil temperature. Then, the sum of the third intermediate pressure and the second compensation pressure is used as the control pressure of the clutch, so that the clutch has sufficient pressure and no slip occurs when the engine is ignited and started.

[0019] In conjunction with the first aspect and the above implementation, in some possible implementations, the method further includes: determining a target filling time based on the fourth engine speed, the fourth engine torque, and the transmission oil temperature; obtaining a filling control time in response to controlling the clutch based on the clutch control pressure; obtaining a second clutch critical pressure, wherein the second clutch critical pressure is a calibration value related to the type of clutch, if the filling control time is greater than or equal to the target filling time; and controlling the clutch based on the second clutch critical pressure.

[0020] In this implementation, the target filling time is determined by using the fourth engine speed, the fourth engine torque, and the transmission oil temperature. When the obtained filling control time is greater than or equal to the target filling time, the clutch is controlled based on the obtained second clutch critical pressure. This allows for timely switching to the next stage when filling is complete, avoiding the impact of continuously providing excessive clutch pressure on the vehicle's stability and improving the coordination of the engine starting process.

[0021] In combination with the first aspect and the above implementation methods, in some possible implementation methods, determining the target filling time based on the fourth engine speed, the fourth engine torque, and the transmission oil temperature includes: determining a basic filling time based on the fourth engine torque and the transmission oil temperature; determining a filling compensation time based on the fourth engine speed and the transmission oil temperature; and using the sum of the basic filling time and the filling compensation time as the target filling time.

[0022] In this implementation, the basic filling time and filling compensation time are determined based on the torque of the fourth engine and the transmission oil temperature, respectively. Then, the sum of the basic filling time and the filling compensation time is used as the target filling time. The total filling time is decomposed into two parts: basic filling and dynamic compensation, and multi-parameter fusion calculation is performed. This allows the target filling time to match the current engine load state and adapt to real-time operating condition fluctuations, thus accurately controlling the filling process.

[0023] Secondly, a clutch control device is provided, the device comprising: The acquisition module is used to acquire the start-stop state of the engine in response to the engine's automatic start-stop function being activated. If the start-stop state is a target state, the module acquires the relevant parameters of the target pressure control stage corresponding to the target state. The target state is located after the start state and before the operation state. The target pressure control stage includes multiple consecutive pressure stages. The determination module is used to determine the target clutch pressure based on the relevant parameters; A control module is used to control the clutch based on the target clutch pressure, wherein the upward trend of the target clutch pressure corresponding to the multiple consecutive pressure stages is different.

[0024] In conjunction with the second aspect, in some possible implementations, the plurality of consecutive pressure stages include a first pressure stage, a second pressure stage, and a third pressure stage. The acquisition module is configured to, when the target pressure control stage is the first pressure stage, acquire a target correction coefficient, a first clutch critical pressure, a first engine torque, a first engine speed, and a first transmission speed, wherein the first pressure stage is used to increase the clutch pressure based on a target calibration time; when the target pressure control stage is the second pressure stage, acquire a second engine torque, a second engine speed, and a second transmission speed, wherein the second pressure stage is used to increase the clutch pressure based on the target pressure; and when the target pressure control stage is the third pressure stage, acquire a third engine torque, a third engine speed, a third transmission speed, and a clutch torque, wherein the third pressure stage is used to control the clutch engagement so that the engine torque output is transmitted to the transmission.

[0025] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the determining module is used to determine a first intermediate pressure based on the first engine torque, the first engine speed, and the first transmission speed when the target pressure control stage is the first pressure stage; correct the first intermediate pressure based on the target correction coefficient to obtain a first compensation pressure; and use the sum of the first compensation pressure and the first clutch critical pressure as the target clutch pressure.

[0026] In combination with the second aspect and the above implementation, in some possible implementations, the determining module is used to determine a first ascending gradient pressure and a pre-control target pressure based on the second engine torque, the second engine speed, and the second transmission speed when the target pressure control stage is the second pressure stage; and to use the first ascending gradient pressure and the pre-control target pressure as the target clutch pressure.

[0027] In combination with the second aspect and the above implementation, in some possible implementations, the acquisition module is used to acquire the target control time in response to the target pressure control stage being the first pressure stage; the device further includes a switching module, used to switch the target pressure control stage from the first pressure stage to the second pressure stage when the target control time is greater than or equal to the target calibration time.

[0028] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the determining module is used to determine the clutch torque-pressure characteristic pressure based on the clutch torque when the target pressure control stage is the third pressure stage; determine the second ascending gradient pressure based on the third engine torque, the third engine speed, and the third transmission speed; correct the second ascending gradient pressure based on the clutch torque-pressure characteristic pressure to obtain a second intermediate pressure; and use the second intermediate pressure as the target clutch pressure.

[0029] In conjunction with the second aspect and the above implementation methods, in some possible implementation methods, the acquisition module is used to acquire the fourth engine speed, the fourth engine torque, and the transmission oil temperature when the start-stop state is the start state; the determination module is used to determine a third intermediate pressure based on the fourth engine torque and the transmission oil temperature, and to determine a second compensation pressure based on the fourth engine speed and the transmission oil temperature; the sum of the third intermediate pressure and the second compensation pressure is used as the clutch control pressure; the control module is used to control the clutch based on the clutch control pressure.

[0030] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the determining module is used to determine the target filling time based on the fourth engine speed, the fourth engine torque, and the transmission oil temperature; the acquiring module is used to acquire the filling control time in response to controlling the clutch based on the clutch control pressure, and to acquire the second clutch critical pressure if the filling control time is greater than or equal to the target filling time, wherein the second clutch critical pressure is a calibration value related to the clutch type; the control module is used to control the clutch based on the second clutch critical pressure.

[0031] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the determining module is used to determine the basic filling time based on the torque of the fourth engine and the transmission oil temperature; determine the filling compensation time based on the speed of the fourth engine and the transmission oil temperature; and take the sum of the basic filling time and the filling compensation time as the target filling time.

[0032] Thirdly, a vehicle is provided, the vehicle including one or more processors and one or more memories, the one or more memories storing at least one piece of program code, the program code being loaded and executed by the one or more processors to implement the operations performed by the clutch control method.

[0033] Fourthly, a computer-readable storage medium is provided, wherein at least one piece of program code is stored therein, the program code being loaded and executed by a processor to implement the operations performed by the clutch control method.

[0034] Fifthly, an electronic device is provided, including a memory and a processor, wherein the memory is used to store executable program code; and the processor is used to call and run the executable program code from the memory, causing the electronic device to perform the data processing method in the first aspect or any possible implementation thereof.

[0035] The technical solution provided in this application, in response to the engine's automatic start-stop function being activated, and when the acquired start-stop state is the target state, acquires relevant parameters for the target pressure control stage corresponding to the target state. Then, based on these parameters, the target clutch pressure is determined in multiple consecutive target pressure control stages. The clutch is controlled based on the target clutch pressure, replacing the slip control process with a segmented pressure control method. This avoids drivability issues that arise during slip control, comprehensively improving the vehicle's driving experience. Furthermore, clutch pressure can be quickly provided in different pressure control stages, eliminating the need to limit engine input torque during start-up and improving overall vehicle starting power. Simultaneously, segmented continuous pressure control enables slip-free control of the gear clutch, reducing clutch slippage during start-up, extending the service life of related components, and improving the smoothness and driving comfort during automatic start-stop restart. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of a slip control process provided in an embodiment of this application. Figure 1 ; Figure 2 This is a schematic diagram of a slip control process provided in an embodiment of this application. Figure 2 ; Figure 3 This is a schematic diagram of an automatic transmission for a vehicle provided in an embodiment of this application; Figure 4 This is a flowchart of a clutch control method provided in an embodiment of this application; Figure 5 This is a flowchart of another clutch control method provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of a clutch control device provided in an embodiment of this application; Figure 7 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application. Detailed Implementation

[0037] The technical solutions in this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0038] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting 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 that feature.

[0039] In order to illustrate the technical solutions provided in the embodiments of this application, some terms involved in the embodiments of this application will be explained below.

[0040] Clutch: A device installed between the engine and the transmission. Its main function is to cut off and connect power, thereby ensuring smooth starting, gear shifting, and braking of the vehicle. The working principle of the clutch is mainly based on using friction to transmit or interrupt power.

[0041] The transmission is a key component in a car used to regulate the engine's output speed and torque, enabling efficient operation under different speed and load conditions. It's a device that changes the engine's power output through a gear system, allowing the vehicle to operate efficiently under varying speeds and loads. It converts the engine's high speed and low torque into low speed and high torque suitable for driving the wheels, thereby enabling functions such as starting, accelerating, decelerating, and reversing the vehicle.

[0042] With the development of vehicle technology, more and more vehicles have automatic start-stop function. Automatic start-stop function is a technology that automatically stops and starts the engine. Its purpose is to stop the engine when the vehicle is stopped and waiting in place, thereby reducing unnecessary fuel consumption and saving fuel.

[0043] In related technologies, after the automatic start-stop function is activated, the engine will disengage when the vehicle starts again. At this time, the transmission gear clutch acts as the starting clutch. A slip control method is used during this process. Based on the engine input torque, the clutch slip is used as the control object, and a closed-loop clutch torque control is introduced. By increasing the clutch pressure, the clutch slip is gradually reduced to below the calibrated value, allowing the vehicle to start moving again. The slip control process of related technologies is as follows: Figure 1 As shown. Figure 1 This is a schematic diagram of a slip control process provided in an embodiment of this application. Figure 1 .

[0044] For example, the engine start-stop state is divided into stop state, start state, ignition state, torque transmission state, and running state. Different engine start-stop states correspond to different pressure control stages. Specifically, the engine speed is divided into: engine speed 11, transmission input speed 12, and transmission output speed 13. The difference between transmission input speed 12 and transmission output speed 13 is the gear clutch slip. Torque includes engine torque 14. Starting from the ignition state, slip control is used to gradually reduce the clutch slip. The engine torque 14 is limited by the torque limiting curve 15 above.

[0045] The above process has several technical flaws: First, the gear clutch hardware is prone to wear and tear due to long-term slippage, shortening its service life. Second, due to hydraulic response delays and changes in clutch friction characteristics, drivability issues can easily arise during start-up slip control. Third, considering the clutch hydraulic response delay, engine output torque is generally limited during slip control, resulting in delayed start-up power response and affecting the overall driving experience. This leads to problems such as low overall vehicle power and poor driving feel.

[0046] Therefore, how to provide sufficient power to the vehicle while the automatic start-stop function is activated is a hot research topic.

[0047] The application scenarios of the technical solutions provided in the embodiments of this application are described below. The technical solutions provided in the embodiments of this application can be applied to different types of vehicles, such as hybrid vehicles, electric vehicles, and pure fuel vehicles. Of course, with the development of science and technology, other types of vehicles may also emerge, and the technical solutions provided in the embodiments of this application are also applicable to other types of vehicles.

[0048] Figure 2 This is a schematic diagram of a slip control process provided in an embodiment of this application. Figure 2 .

[0049] For example, the engine start-stop state is divided into a stopped state, a starting state, an ignition state, a torque transmission state, and an operating state. Different engine start-stop states correspond to different pressure control stages. Specifically, the engine speed is divided into: engine speed 11, transmission input speed 12, and transmission output speed 13. The difference between transmission input speed 12 and transmission output speed 13 is the gear clutch slip. Torque includes engine torque 14. Compared to related technologies that use slip control to gradually reduce clutch slip, this application uses pressure pre-control P0 (corresponding to the first pressure stage), pressure pre-control P1 (corresponding to the second pressure stage), and overpressure (corresponding to the third pressure stage) to control the clutch pressure in segments. Furthermore, the clutch pressure is also controlled in segments during the oil filling stage and the critical pressure stage. Specifically, during the oil filling stage, the clutch control pressure 21 is used as the clutch pressure, and the control duration of the clutch control pressure 21 is determined based on the target oil filling time 22. During the critical pressure stage, the clutch critical pressure 23 is used as the clutch pressure. In pressure pre-control P0, a first pressure 24 is used as the clutch pressure, where the first pressure 24 is the sum of the clutch critical pressure 23 and the first compensation pressure. In pressure pre-control P1, a first ascending gradient pressure 25 is used to control the clutch pressure to rise to the pre-controlled target pressure 26. In the overpressure stage, a second intermediate pressure 27 is used to control the clutch pressure to gradually rise until the engine can operate normally. Figure 2 and Figure 1 The comparison shows that the engine torque 14 obtained through the technical solution of this application is greater than the engine torque 14 obtained through the slip control process of related technologies.

[0050] It should be noted that the clutch pressure in the above five stages is obtained by looking up tables (including the first corresponding table, the second corresponding table, and all corresponding tables mentioned below). Different tables are set for different stages. Furthermore, the clutch hydraulic response delay has been pre-controlled during the setting of the table values, and a higher clutch pressure has been set. At the same time, the table lookup is triggered when entering different stages. Compared with the slow increase of clutch pressure during slip control, the pressure request can be issued in advance to ensure that the clutch pressure is sufficient in each pressure control stage. No matter how fast the engine torque increases, the torque transmitted on the clutch will be greater than the engine torque at every moment. This can reduce gear clutch slippage and extend service life without limiting the engine input torque to improve the overall vehicle power.

[0051] Furthermore, the technical solution of this application is applicable to automatic transmissions equipped with hydraulic torque converters. For example... Figure 3 As shown, Figure 3This is a schematic diagram of an automatic transmission for a vehicle provided in an embodiment of this application. Exemplarily, the automatic transmission consists of a torque converter and a gear clutch, and is connected to the engine. Through this automatic transmission, friction between the engine speed and the transmission input speed can be reduced due to the hydraulic force, improving the driving experience.

[0052] After adopting the technical solution provided in this application embodiment, in response to the engine's automatic start-stop function being activated, and when the acquired start-stop state is the target state, relevant parameters of the target pressure control stage corresponding to the target state are acquired. Thus, in multiple consecutive pressure control stages, the target clutch pressure is determined based on the relevant parameters, and the clutch is controlled based on the target clutch pressure. This segmented pressure control method replaces the slip control process, thereby avoiding drivability issues that occur during slip control and comprehensively improving the vehicle's driving experience. Furthermore, clutch pressure can be quickly provided in different pressure control stages, eliminating the need to limit engine input torque during start-up and improving the vehicle's starting power. Simultaneously, segmented continuous pressure control enables slip-free control of the gear clutch, reducing clutch slippage during start-up, extending the service life of related components, and improving the smoothness and driving comfort during automatic start-stop restart.

[0053] After introducing the application scenarios of the embodiments of this application, the technical solutions provided by the embodiments of this application will be described below. (See also...) Figure 4 The method includes the following steps.

[0054] 401. In response to the engine's automatic start-stop function being activated, obtain the engine's start-stop status.

[0055] Automatic start-stop function is a technology that automatically stops and starts the engine. Its purpose is to stop the engine from working when the vehicle is stopped and waiting, reducing unnecessary fuel consumption and thus saving fuel. In some embodiments, the automatic start-stop function can be active or inactive. The automatic start-stop function is active by default and can be switched using a function button on the vehicle. The engine's start-stop state can include, but is not limited to, at least one of the following: off, starting, ignition, torque transmission, and running. The engine's start-stop state changes gradually according to the start-up duration. The off state refers to a state where the engine is completely shut down, all systems have stopped working, there is no combustion, and no power output. The starting state refers to the state where the starter motor is rotating the crankshaft to bring the engine to combustible speed. The ignition state refers to the state where the ignition system is energized, and the spark plugs generate an electric spark to ignite the air-fuel mixture in the cylinder. The torque transmission state refers to the state where the torque output by the engine is transmitted to the wheels through the transmission system, driving the vehicle. Operating status refers to the state in which the engine has successfully started and continues to run, completing the working cycle of intake, compression, power, and exhaust. In some embodiments, the start / stop status can be obtained based on Controller Area Network (CAN) signals. CAN is a serial communication protocol bus used for real-time applications. It can use twisted-pair cables to transmit signals and is one of the most widely used fieldbuses in the world.

[0056] 402. When the start-stop state is the target state, obtain the relevant parameters of the target pressure control stage corresponding to the target state. The target state is located after the start state and before the operation state. The target pressure control stage includes multiple consecutive pressure stages.

[0057] The target state is the state used for segmented control of clutch pressure. In some embodiments, the target state is a partial state of the engine's start-stop state. The engine's start-stop states have a certain sequence, for example, the start-stop states change sequentially in the order of stop state, start state, ignition state, torque transmission state, and operation state. The target state is located after the start state and before the operation state. The target state may include, but is not limited to, ignition state and operation state. The target pressure control stage is the stage at which the clutch is controlled under the target state. In some embodiments, the target pressure control stage includes multiple consecutive pressure stages, and the clutch can be controlled sequentially according to multiple consecutive pressure stages. The specific process of controlling the clutch differs between different pressure stages. The target pressure control stage may include, but is not limited to, a first pressure stage, a second pressure stage, and a third pressure stage. The first pressure stage is used to increase the clutch pressure based on a target calibration time. The second pressure stage is used to increase the clutch pressure based on the target pressure. The third pressure stage is used to control clutch engagement so that the engine torque output is transmitted to the transmission. Relevant parameters may include, but are not limited to, at least one of the following: target correction coefficient, clutch critical pressure, engine torque, engine speed, transmission speed, clutch torque, transmission oil temperature, etc. Different pressure stages in the target pressure control process correspond to different relevant parameters. In some embodiments, relevant parameters and start / stop status can be continuously acquired periodically at preset time intervals based on CAN signals. The time interval can be any suitable size, such as 10ms, 50ms, etc.

[0058] It should be noted that different target states correspond to different target pressure control stages. However, different target pressure control stages can correspond to the same target state or different target states. Specifically, when the target state changes, the target pressure control stage will switch. However, when the target pressure control stage switches, the target state may or may not change. Therefore, the current pressure stage can be determined based on the engine's start-stop status.

[0059] 403. Determine the target clutch pressure based on relevant parameters, and control the clutch based on the target clutch pressure. The upward trend of the target clutch pressure corresponding to multiple consecutive pressure stages is different.

[0060] The relevant parameters may include, but are not limited to, at least one of the following: target correction coefficient, clutch critical pressure, engine torque, engine speed, transmission speed, clutch torque, transmission oil temperature, etc. The relevant parameters differ for different pressure stages within the target pressure control phase. The target clutch pressure is used to control clutch engagement, ensuring that the clutch does not slip in each control stage and that all engine torque is transmitted to the wheels via the clutch. In some embodiments, in different target pressure control stages, the target clutch pressure is the pressure involved in clutch control; it can be the pressure directly applied to the clutch, or it can be the target pressure that the clutch needs to achieve in the current target pressure control stage.

[0061] It should be noted that, because relevant parameters and start / stop status can be continuously acquired periodically at preset time intervals based on CAN signals, the process of determining the target clutch pressure is also continuous and real-time. This ensures that the clutch pressure at each moment is accurate and suitable for the real-time state of the engine. Furthermore, the different upward trends of the target clutch pressure corresponding to multiple consecutive pressure stages allow for segmented control of the clutch pressure, enabling targeted control of the clutch pressure at each pressure stage.

[0062] The technical solution provided in this application, in response to the engine's automatic start-stop function being activated, and when the acquired start-stop state is the target state, acquires relevant parameters for the target pressure control stage corresponding to the target state. Then, based on these parameters, the target clutch pressure is determined in multiple consecutive target pressure control stages. The clutch is controlled based on the target clutch pressure, replacing the slip control process with a segmented pressure control method. This avoids drivability issues that arise during slip control, comprehensively improving the vehicle's driving experience. Furthermore, clutch pressure can be quickly provided in different pressure control stages, eliminating the need to limit engine input torque during start-up and improving overall vehicle starting power. Simultaneously, segmented continuous pressure control enables slip-free control of the gear clutch, reducing clutch slippage during start-up, extending the service life of related components, and improving the smoothness and driving comfort during automatic start-stop restart.

[0063] It should be noted that steps 401-403 above are a simplified description of the clutch control method provided in the embodiments of this application. The clutch control method provided in the embodiments of this application will be described in more detail below with some examples. See [link to relevant documentation]. Figure 5 The method includes the following steps.

[0064] 501. In response to the engine's automatic start-stop function being activated, obtain the engine's start-stop status.

[0065] The automatic start-stop function is a technology that automatically stops and starts the engine. Its purpose is to stop the engine from running when the vehicle is stopped and stationary, reducing unnecessary fuel consumption and thus saving fuel. In some embodiments, the automatic start-stop function can be active or inactive. The automatic start-stop function is active by default and its state can be switched using a function button on the vehicle. The engine's start-stop state can include, but is not limited to, at least one of the following: stopped, started, ignition, torque transmission, and running. In some embodiments, the start-stop state can be obtained based on Controller Area Network (CAN) signals.

[0066] 502. When the start-stop state is in the start state, obtain the fourth engine speed, the fourth engine torque, and the transmission oil temperature.

[0067] Engine speed (including the fourth engine speed and all engine speeds mentioned below) refers to the number of revolutions of the engine crankshaft per unit time. The fourth engine speed is the engine speed obtained when the start-stop state is changed to the start state. Engine torque (including the fourth engine torque and all engine torques mentioned below) refers to the rotational torque output by the engine crankshaft. The fourth engine torque is the engine torque obtained when the start-stop state is changed to the start state. Transmission oil temperature refers to the actual operating temperature of the lubricating oil inside the automatic or manual transmission. In some embodiments, the fourth engine speed and fourth engine torque are obtained via a CAN signal, and the transmission oil temperature is obtained via a temperature sensor installed in the transmission. In some embodiments, in response to the start-stop state switching from a stopped state to a start state, the pressure control phase is switched to the oil filling phase.

[0068] 503. Determine the third intermediate pressure based on the fourth engine torque and transmission oil temperature, and determine the second compensation pressure based on the fourth engine speed and transmission oil temperature.

[0069] The third intermediate pressure is the base pressure for oil filling determined during the oil filling stage. The second compensation pressure is the compensation pressure for oil filling determined during the oil filling stage.

[0070] In some embodiments, the third intermediate pressure is obtained by querying the first relationship table based on the fourth engine torque and the transmission oil temperature.

[0071] The first relational table stores multiple fourth engine torques and transmission oil temperatures, as well as the corresponding third intermediate pressures for each fourth engine torque and transmission oil temperature. By querying the first relational table using the fourth engine torque and transmission oil temperature, the third intermediate pressure can be obtained. Specifically, the fourth engine torque and transmission oil temperature are set as breakpoints in the first relational table using integers. The actual obtained fourth engine torque or transmission oil temperature can be used to determine the third intermediate pressure through linear interpolation.

[0072] For example, let the fourth engine torque be denoted as Eng_NetTrq, the transmission oil temperature as T_TMOil, and the third intermediate pressure as P_FillBase_ij. The first relation table can be in the following form:

[0073] In some embodiments, the second compensation pressure is obtained by querying a second relationship table based on the fourth engine speed and transmission oil temperature.

[0074] The second relational table stores multiple fourth engine speeds and transmission oil temperatures, along with the corresponding second compensation pressures for each. By querying the second relational table using the fourth engine speed and transmission oil temperature, the second compensation pressure can be obtained. Specifically, the fourth engine speed and transmission oil temperature are set as breakpoints in the second relational table using integers. The actual obtained fourth engine speed and transmission oil temperature can be used to determine the second compensation pressure through linear interpolation.

[0075] For example, let the fourth engine speed be denoted as N_EngSpd, the transmission oil temperature as T_TMOi, and the second compensation pressure as P_FillOfs_ij. The second relationship table can be in the following form:

[0076] 504. The sum of the third intermediate pressure and the second compensation pressure is used as the clutch control pressure.

[0077] In this design, the sum of the third intermediate pressure and the second compensation pressure is used as the target filling pressure, and the target filling pressure is used as the clutch control pressure. In some embodiments, the third intermediate pressure is denoted as P_FillBase_ij, the second compensation pressure is denoted as P_FillOfs_ij, and the target filling pressure P_FillTgt can be: P_FillTgt = P_FillBase_ij + P_FillOfs_ij.

[0078] 505. Clutch control based on clutch control pressure.

[0079] The clutch control pressure is the force that controls the filling of the clutch during the filling phase. In some embodiments, when the clutch engagement is controlled based on the clutch control pressure, the clutch control pressure causes the transmission fluid to quickly fill the clutch chamber, pushing the clutch piston to overcome the spring preload and move forward, thereby reducing the gap between the steel plates and friction plates inside the clutch, so that the clutch is in a critical state where it can just transmit torque.

[0080] In this implementation, when the start-stop state is the start state, the third intermediate pressure is determined by the fourth engine torque and the transmission oil temperature, and the second compensation pressure is determined by the fourth engine speed and the transmission oil temperature. Then, the sum of the third intermediate pressure and the second compensation pressure is used as the clutch control pressure, so that the clutch has sufficient pressure and no slip occurs when the engine is ignited and started.

[0081] In one possible implementation, a target filling time is determined based on the fourth engine speed, fourth engine torque, and transmission oil temperature. A filling control time is obtained in response to controlling the clutch based on clutch control pressure. If the filling control time is greater than or equal to the target filling time, a second clutch critical pressure, which is a calibration value related to the clutch type, is obtained. The clutch is then controlled based on the second clutch critical pressure.

[0082] The fourth engine speed is the engine speed obtained when the start-stop state is changed to the start state. The fourth engine torque is the engine torque obtained when the start-stop state is changed to the start state. The transmission fluid temperature refers to the actual operating temperature of the lubricating oil inside the automatic or manual transmission. The target filling time refers to the target control duration of the filling phase. The filling control time refers to the actual control duration of the filling phase. The target filling time can be any suitable value, such as 5 seconds, 3 seconds, etc. The filling control time can be any suitable value, such as 0.5 seconds, 2.3 seconds, etc. In some embodiments, in response to entering the filling phase, the target filling time is determined based on the fourth engine speed, the fourth engine torque, and the transmission fluid temperature. The target filling time does not exceed the start time of the engine starter.

[0083] In some embodiments, in response to clutch control based on clutch control pressure, the oil filling control time is obtained via a target timer. The target timer is a device with a timing function. The target timer may include, but is not limited to, a debounce timer, a filter timer, etc. A debounce timer is a timer used in a control system to filter transient signal fluctuations and ensure the reliability of state transitions. A filter timer is a timer used for low-pass filtering, removing high-frequency noise and invalid jitter.

[0084] Clutch critical pressure (including the second clutch critical pressure and all clutch critical pressures mentioned below) refers to the critical pressure point at which the clutch can just transmit torque. In some embodiments, the clutch critical pressure is a calibration value related to the clutch type. When the filling control time is greater than or equal to the target filling time, the pressure control phase is switched from the filling phase to the critical pressure phase (also known as the KP phase), the second clutch critical pressure is obtained, and the clutch is controlled based on the second clutch critical pressure. When the filling control time is less than the target filling time, the filling phase continues to be used as the current pressure control phase, and the filling control time is continuously obtained for judgment. The purpose of the critical pressure phase is to prevent the gear clutch from transmitting torque, reduce the load during engine start-up, and make the engine start more easily and smoothly.

[0085] In this implementation, the target filling time is determined by using the fourth engine speed, the fourth engine torque, and the transmission oil temperature. When the obtained filling control time is greater than or equal to the target filling time, the clutch is controlled based on the obtained second clutch critical pressure. This allows for timely switching to the next stage when filling is complete, avoiding the impact of continuously providing excessive clutch pressure on the vehicle's stability and improving the coordination of the engine starting process.

[0086] In one possible implementation, a base filling time is determined based on the fourth engine torque and transmission fluid temperature. A filling compensation time is determined based on the fourth engine speed and transmission fluid temperature. The sum of the base filling time and the filling compensation time is used as the target filling time.

[0087] The base filling time is the fundamental time value within the target filling time. The base filling time can be any suitable value, such as 4.5s, 3.6s, etc. The filling compensation time is the time value used to compensate for the base filling time. The filling compensation time can be any suitable value, such as 0.3s, 0.42s, etc.

[0088] In some embodiments, the basic filling time is obtained by querying a third relation table based on the fourth engine torque and transmission oil temperature.

[0089] The third relation table stores multiple fourth engine torques and transmission oil temperatures, along with the corresponding base filling times for each. By querying this fourth engine torque and transmission oil temperature in the third relation table, the base filling time can be obtained. Specifically, the fourth engine torque and transmission oil temperature are set as breakpoints in the third relation table using integers. The actual base filling time for the obtained fourth engine torque or transmission oil temperature can be determined using linear interpolation.

[0090] For example, let the fourth engine torque be denoted as Eng_NetTrq, the transmission oil temperature as T_TMOil, and the base fill time as t_FillBase_ij. The third relation table can be in the following form:

[0091] In some embodiments, the oil filling compensation time is obtained by querying a fourth relation table based on the fourth engine speed and transmission oil temperature.

[0092] The fourth relation table stores multiple fourth engine speeds and transmission oil temperatures, along with the corresponding oil filling compensation times for each. By querying this fourth engine speed and transmission oil temperature in the fourth relation table, the oil filling compensation time can be obtained. Specifically, the fourth engine speed and transmission oil temperature are set as breakpoints in the fourth relation table using integers. The actual obtained fourth engine speed and transmission oil temperature can be used to determine the oil filling compensation time using linear interpolation.

[0093] For example, let the fourth engine speed be denoted as N_EngSpd, the transmission oil temperature as T_TMOi, and the oil filling compensation time as t_FillOfs_ij. The fourth relation table can be in the following form:

[0094] In some embodiments, the sum of the base filling time and the filling compensation time is used as the target filling time. The base filling time is denoted as t_FillBase_ij, the filling compensation time is denoted as t_FillOfs_ij, and the target filling pressure t_FillTgt can be: t_FillTgt = t_FillBase_ij + t_FillOfs_ij.

[0095] In this implementation, the basic filling time and filling compensation time are determined based on the torque of the fourth engine and the transmission oil temperature, respectively. Then, the sum of the basic filling time and the filling compensation time is used as the target filling time. The total filling time is decomposed into two parts: basic filling and dynamic compensation, and multi-parameter fusion calculation is performed. This allows the target filling time to match the current engine load state and adapt to real-time operating condition fluctuations, thus accurately controlling the filling process.

[0096] 506. When the start-stop state is the target state, obtain the relevant parameters of the target pressure control stage corresponding to the target state. The target state is located after the start state and before the operation state. The target pressure control stage includes multiple consecutive pressure stages.

[0097] The target state is the state used for segmented control of clutch pressure. In some embodiments, the target state is a partial state of the engine's start-stop state. The target state may include, but is not limited to, ignition state, running state, etc. The target pressure control stage is the stage at which the clutch is controlled under the target state. In some embodiments, the target pressure control stage includes multiple consecutive pressure stages, and the clutch can be controlled sequentially according to multiple consecutive pressure stages. The specific process of controlling the clutch differs between different pressure stages. The target pressure control stage may include, but is not limited to, a first pressure stage, a second pressure stage, and a third pressure stage. Relevant parameters may include, but are not limited to, at least one of the following: target correction coefficient, clutch critical pressure, engine torque, engine speed, transmission speed, clutch torque, transmission oil temperature, etc. The relevant parameters corresponding to different pressure stages in the target pressure control stage are different. In some embodiments, relevant parameters and start-stop states can be continuously acquired periodically at preset time intervals based on CAN signals. The time interval can be any suitable size, such as 10ms, 50ms, etc.

[0098] In one possible implementation, multiple consecutive pressure stages include a first pressure stage, a second pressure stage, and a third pressure stage. When the target pressure control stage is the first pressure stage, a target correction coefficient, a first clutch critical pressure, a first engine torque, a first engine speed, and a first transmission speed are acquired. The first pressure stage is used to increase the clutch pressure based on a target calibration time. When the target pressure control stage is the second pressure stage, a second engine torque, a second engine speed, and a second transmission speed are acquired. The second pressure stage is used to increase the clutch pressure based on the target pressure. When the target pressure control stage is the third pressure stage, a third engine torque, a third engine speed, a third transmission speed, and a clutch torque are acquired. The third pressure stage is used to control clutch engagement, allowing engine torque output to be transmitted to the transmission.

[0099] The first pressure stage is used to increase the clutch pressure based on a target calibration time. In some embodiments, in response to the start-stop state switching from the start state to the ignition state, the start-stop state is determined as the target state, and the pressure control stage is switched from the critical pressure stage to the first pressure stage. The target correction coefficient is a coefficient used to correct the first intermediate pressure. The target correction coefficient can be calibrated as needed, with a calibration range of [0, 1]. The first clutch critical pressure is a calibration value related to the clutch type. In some embodiments, the first clutch critical pressure and the second clutch critical pressure are the same. The first engine torque is the engine speed obtained when the target pressure control stage is the first pressure stage. The first engine speed is the engine speed obtained when the target pressure control stage is the first pressure stage. The transmission speed (including the first transmission speed and all transmission speeds mentioned below) refers to the rotational speed of the transmission input shaft. The first transmission speed is the transmission speed obtained when the target pressure control stage is the first pressure stage.

[0100] The second pressure stage is used to increase the clutch pressure based on the target pressure. The second engine torque is the engine speed obtained when the target pressure control stage is in the second pressure stage. The second engine speed is the engine speed obtained when the target pressure control stage is in the second pressure stage. The second transmission speed is the transmission speed obtained when the target pressure control stage is in the second pressure stage.

[0101] It should be noted that the first pressure stage and the second pressure stage are collectively referred to as the pressure pre-control stage. The pressure pre-control stage allows the clutch to request more pressure based on the clutch's critical pressure, enabling the clutch to quickly pass through the nonlinear region of clutch torque and pressure characteristics, improving the actual pressure following characteristics, and preventing slippage of the gear clutch in the subsequent torque transmission stage due to pressure following difference.

[0102] The third pressure stage is used to control clutch engagement, allowing engine torque output to be transmitted to the transmission. The third engine torque is the engine speed obtained when the target pressure control stage is at the third pressure stage. The third engine speed is the engine speed obtained when the target pressure control stage is at the third pressure stage. The third transmission speed is the transmission speed obtained when the target pressure control stage is at the third pressure stage. Clutch torque refers to the maximum torque that the clutch can reliably transmit when fully engaged.

[0103] In this implementation, different relevant parameters are acquired at different stages of multiple consecutive pressure phases, thereby enabling the targeted determination of the clutch pressure at different pressure phases. The clutch pressure control is dynamically adjusted based on the relevant parameters acquired in real time, so that the clutch pressure control can not only respond quickly to driving intentions, but also adapt to changes in operating conditions, ensuring the continuity and stability of power transmission.

[0104] 507. Determine the target clutch pressure based on relevant parameters, and control the clutch based on the target clutch pressure.

[0105] The relevant parameters may include, but are not limited to, at least one of the following: target correction coefficient, clutch critical pressure, engine torque, engine speed, transmission speed, clutch torque, transmission oil temperature, etc. The relevant parameters differ for different pressure stages within the target pressure control phase. The target clutch pressure is used to control clutch engagement, ensuring that the clutch does not slip in each control stage and that all engine torque is transmitted to the wheels via the clutch.

[0106] In one possible implementation, when the target pressure control stage is the first pressure stage, a first intermediate pressure is determined based on the first engine torque, the first engine speed, and the first transmission speed. The first intermediate pressure is corrected based on a target correction coefficient to obtain a first compensated pressure. The sum of the first compensated pressure and the first clutch critical pressure is taken as the target clutch pressure.

[0107] The first pressure stage is used to increase the clutch pressure based on the target calibration time. The first intermediate pressure is the pressure compensation value determined in the first pressure stage. The target correction coefficient is a coefficient used to correct the first intermediate pressure. The target correction coefficient can be calibrated as needed, with a calibration range of [0, 1]. The first clutch critical pressure is a calibration value related to the clutch type. The first engine torque is the engine speed obtained when the target pressure control stage is the first pressure stage. The first engine speed is the engine speed obtained when the target pressure control stage is the first pressure stage. The first transmission speed is the transmission speed obtained when the target pressure control stage is the first pressure stage.

[0108] In some embodiments, a first speed difference is determined based on a first engine speed and a first transmission speed, and then a first intermediate pressure is determined based on a first engine torque and the first speed difference. In some embodiments, the first engine speed is denoted as N_EngSpd, the first transmission speed is denoted as N_TMInput, and the first speed difference N_Slip can be: N_Slip = N_EngSpd – N_TMInput.

[0109] In some embodiments, the first intermediate pressure is obtained by querying a fifth relation table based on the difference between the first engine torque and the first speed.

[0110] The fifth relation table stores multiple differences between first engine torque and first speed, as well as the corresponding first intermediate pressure for each difference. By querying the fifth relation table using these first engine torque and first speed differences, the first intermediate pressure can be obtained. Specifically, the first engine torque and first speed differences are set as breakpoints in the fifth relation table using integers. The actual obtained first engine torque and first speed differences can be used to determine the first intermediate pressure through linear interpolation.

[0111] For example, let the first engine torque be denoted as Eng_NetTrq, the first speed difference as N_Slip, and the first intermediate pressure as P_PreCltPOOft_ij. The fifth relationship table can be in the following form:

[0112] The first compensation pressure is the pressure value obtained by correcting the first intermediate pressure with a target correction coefficient. In some embodiments, the target correction coefficient can be calibrated as needed, with a calibration range of [0, 1]. The first compensation pressure can be obtained by correcting the first intermediate pressure with the target correction coefficient by multiplying the target correction coefficient and the first intermediate pressure. In some embodiments, the sum of the first compensation pressure and the first clutch critical pressure is used as the target clutch pressure. The first intermediate pressure is denoted as P_PreCltPOOft_ij, the first compensation pressure is denoted as k*P_PreCltPOOft_ij, and the first clutch critical pressure is denoted as P_Kisspoint. The target clutch pressure P_PreCltP0 can be: P_PreCltP0 = P_Kisspoint + k*P_PreCltPOOft_ij. Where k is the target correction coefficient.

[0113] It should be noted that when the target pressure control stage is the first pressure stage, the clutch needs to request more pressure based on the clutch critical pressure. However, the target clutch pressure should be a smooth increase. Therefore, the first intermediate pressure needs to be corrected based on the target correction coefficient to obtain the first compensation pressure. Furthermore, the target correction coefficient can be different at different times, so as to achieve a smooth increase in the target clutch pressure.

[0114] In this implementation, when the target pressure control stage is the first pressure stage, the first intermediate pressure is determined by the first engine torque, the first engine speed, and the first transmission speed. Then, the first intermediate pressure is corrected by the target correction coefficient to obtain the first compensation pressure. The sum of the first compensation pressure and the first clutch critical pressure is then used as the target clutch pressure. This allows the clutch pressure to increase steadily based on the clutch critical pressure, enhancing the response speed and smoothness of pressure control, and improving driving comfort and transmission system coordination.

[0115] In one possible implementation, when the target pressure control phase is the second pressure phase, a first ascending gradient pressure and a pre-controlled target pressure are determined based on the second engine torque, the second engine speed, and the second transmission speed. The first ascending gradient pressure and the pre-controlled target pressure are then used as the target clutch pressure.

[0116] The second pressure phase is used to increase the clutch pressure based on a target pressure. In some embodiments, the second pressure phase is the pressure phase following the end of the first pressure phase, and the second and first pressure phases are continuous. The second engine torque is the engine torque obtained when the target pressure control phase is the second pressure phase. The second engine speed is the engine speed obtained when the target pressure control phase is the second pressure phase. The second transmission speed is the transmission speed obtained when the target pressure control phase is the second pressure phase. The first gradient pressure is used to increase the clutch pressure in the second pressure phase. The pre-controlled target pressure is used to characterize the target value that the clutch pressure needs to reach in the second pressure phase.

[0117] In some embodiments, a second speed difference is determined based on the second engine speed and the second transmission speed, and then a first ascending gradient pressure and a pre-controlled target pressure are determined based on the second engine torque and the second speed difference. In some embodiments, the second engine speed is denoted as N_EngSpd, the second transmission speed is denoted as N_TMInput, and the second speed difference N_Slip can be: N_Slip = N_EngSpd – N_TMInput.

[0118] In some embodiments, the first ascending gradient pressure is obtained by querying the sixth relation table based on the difference between the second engine torque and the second speed.

[0119] The sixth relation table stores multiple differences between the second engine torque and the second engine speed, as well as the corresponding first upward gradient pressure for each difference. By querying the sixth relation table using the difference between the second engine torque and the second engine speed, the first upward gradient pressure can be obtained. Specifically, the difference between the second engine torque and the second engine speed is set as an integer breakpoint in the sixth relation table. The actual obtained difference between the second engine torque and the second engine speed can be used to determine the first upward gradient pressure through linear interpolation.

[0120] For example, the second engine torque is denoted as Eng_NetTrq, the second speed difference as N_Slip, and the first ascending gradient pressure as P_PdtP1CltRp_ij. The sixth relation table can be in the following form:

[0121] In some embodiments, the pre-controlled target pressure is obtained by querying the seventh relation table based on the difference between the second engine torque and the second speed.

[0122] The seventh relation table stores multiple differences between the second engine torque and the second engine speed, along with the corresponding pre-control target pressures. By querying this second engine torque and second engine speed difference in the seventh relation table, the pre-control target pressure can be obtained. Specifically, the second engine torque and second engine speed difference are set as breakpoints in the seventh relation table using integers. The actual obtained second engine torque and second engine speed difference can be used to determine the pre-control target pressure using a linear interpolation method.

[0123] For example, let the second engine torque be denoted as Eng_NetTrq, the second speed difference as N_Slip, and the pre-controlled target pressure as P_PreCltP1Tgt_ij. The seventh relationship table can be in the following form:

[0124] In some embodiments, the first ascending gradient pressure and the pre-controlled target pressure are used as the target clutch pressure, and the clutch pressure is gradually increased to the pre-controlled target pressure based on the first ascending gradient pressure, thereby maintaining the clutch pressure at the pre-controlled target pressure until the ignition state ends.

[0125] In this implementation, when the target pressure control stage is the second pressure stage, the first ascending gradient pressure and the pre-controlled target pressure are determined by the second engine torque, the second engine speed, and the second transmission speed. Then, the clutch pressure is increased to the pre-controlled target pressure using the first ascending gradient pressure. This allows the clutch pressure to be increased according to the expected clutch pressure in the second pressure stage, thus optimizing the transition capability of the power system from restart to smooth operation during the automatic start-stop process.

[0126] In one possible implementation, in response to the target pressure control stage being a first pressure stage, the target control time is acquired. If the target control time is greater than or equal to the target calibration time, the target pressure control stage is switched from the first pressure stage to a second pressure stage.

[0127] Since both the first and second pressure stages are pressure stages under ignition conditions, the stage switching needs to be completed according to the target control time. The target control time is the control duration of the first pressure stage. The target control time can be any suitable size, such as 1.2s, 0.6s, etc. In some embodiments, the target control time is obtained through a target timer in response to entering the first pressure stage. The target calibration time refers to the target control duration of the first pressure stage. The target calibration time can be any suitable size, such as 15s, 0.9s, etc.

[0128] In some embodiments, if the target control time is greater than or equal to the target calibration time, the target pressure control stage is switched from the first pressure stage to the second pressure stage. If the target control time is less than the target calibration time, the first pressure stage continues to be used as the target pressure control stage, and the target control time is continuously acquired for determination.

[0129] In this implementation, the target control time is acquired when the target pressure control stage is the first pressure stage. Then, if the target control time is greater than or equal to the target calibration time, the target pressure control stage is switched from the first pressure stage to the second pressure stage. This not only prevents insufficient pressure and unstable power engagement that may result from switching to the second pressure stage too early, but also avoids response delays caused by excessive time consumption in the first pressure stage, thus achieving a stable transition between control stages.

[0130] In one possible implementation, when the target pressure control stage is the third pressure stage, the clutch torque-pressure characteristic pressure is determined based on the clutch torque. A second ascending gradient pressure is determined based on the third engine torque, the third engine speed, and the third transmission speed. The second ascending gradient pressure is corrected based on the clutch torque-pressure characteristic pressure to obtain a second intermediate pressure. This second intermediate pressure is then used as the target clutch pressure.

[0131] The third pressure stage is used to control clutch engagement, enabling engine torque output to be transmitted to the transmission. In some embodiments, the pressure control stage switches from the second pressure stage to the third pressure stage in response to a switch from ignition to torque transmission during a start-stop state. The third engine torque is the engine torque obtained when the target pressure control stage is the third pressure stage. The third engine speed is the engine speed obtained when the target pressure control stage is the third pressure stage. The third transmission speed is the transmission speed obtained when the target pressure control stage is the third pressure stage. Clutch torque refers to the maximum torque that the clutch can reliably transmit in a fully engaged state. The second gradient pressure is used to increase the clutch pressure in the third pressure stage. The clutch torque-pressure characteristic pressure is used to correct the second gradient pressure. In some embodiments, there is a mapping relationship between the clutch torque and the clutch torque-pressure characteristic pressure; after obtaining the clutch torque, the clutch torque-pressure characteristic pressure can be determined based on this mapping relationship.

[0132] In some embodiments, a third speed difference is determined based on the third engine speed and the third transmission speed, and then a second ascending gradient pressure is determined based on the third engine torque and the third speed difference. In some embodiments, the third engine speed is denoted as N_EngSpd, the third transmission speed is denoted as N_TMInput, and the third speed difference N_Slip can be: N_Slip = N_EngSpd – N_TMInput.

[0133] In some embodiments, the second ascending gradient pressure is obtained by querying the eighth relation table based on the difference between the third engine torque and the third speed.

[0134] The eighth relation table stores multiple differences between the torque and speed of the third engine, as well as the corresponding second ascending gradient pressure for each difference. By querying the eighth relation table using these differences, the second ascending gradient pressure can be obtained. Specifically, the differences between the torque and speed of the third engine are set as integer breakpoints in the eighth relation table. The actual obtained differences between the torque and speed of the third engine can be used to determine the second ascending gradient pressure through linear interpolation.

[0135] For example, the third engine torque is denoted as Eng_NetTrq, the third speed difference as N_Slip, and the second ascending gradient pressure as P_LPRp_ij. The eighth relation table can be in the following form:

[0136] In some embodiments, the minimum and maximum gradient pressure values ​​are determined based on the clutch torque-pressure characteristic pressure. Then, the second ascending gradient pressure is corrected based on these values ​​to obtain a second intermediate pressure. Specifically, the product of the clutch torque-pressure characteristic pressure and a first pressure coefficient is used as the minimum gradient pressure, and the product of the clutch torque-pressure characteristic pressure and a second pressure coefficient is used as the maximum gradient pressure. The first pressure coefficient is less than the second pressure coefficient. The first pressure coefficient can be any suitable value, for example, 0.9 or 0.8. The second pressure coefficient can be any suitable value, for example, 1.3 or 1.5.

[0137] In some embodiments, when correcting the second ascending gradient pressure based on the minimum and maximum gradient pressure values, the minimum of the second ascending gradient pressure and the maximum gradient pressure is determined as the first intermediate gradient pressure. The maximum of the first intermediate gradient pressure and the minimum gradient pressure is determined as the second intermediate pressure. Then, the second intermediate pressure is used as the target clutch pressure, thereby controlling the increase of clutch pressure based on the second intermediate pressure.

[0138] In this implementation, when the target pressure control stage is the third pressure stage, the clutch torque-pressure characteristic pressure is determined using the clutch torque, and the second ascending gradient pressure is determined using the third engine torque, the third engine speed, and the third transmission speed. The second intermediate pressure obtained by correcting the second ascending gradient pressure using the clutch torque-pressure characteristic pressure is used as the target clutch pressure. This allows for the constraint of the real-time determined second ascending gradient pressure in the third pressure stage, improving the accuracy of the target clutch pressure and ensuring the smoothness of power boost.

[0139] Figure 6 This is a schematic diagram of the structure of a clutch control device provided in an embodiment of this application. See also... Figure 6 The clutch control device 600 includes: The acquisition module 601 is used to acquire the start-stop state of the engine in response to the engine's automatic start-stop function being activated. When the start-stop state is the target state, it acquires the relevant parameters of the target pressure control stage corresponding to the target state. The target state is located after the start state and before the operation state. The target pressure control stage includes multiple consecutive pressure stages. Module 602 is used to determine the target clutch pressure based on relevant parameters; The control module 603 is used to control the clutch based on the target clutch pressure, and the upward trend of the target clutch pressure is different for multiple consecutive pressure stages.

[0140] In one possible implementation, multiple consecutive pressure stages include a first pressure stage, a second pressure stage, and a third pressure stage. The acquisition module 601 is configured to acquire a target correction coefficient, a first clutch critical pressure, a first engine torque, a first engine speed, and a first transmission speed when the target pressure control stage is the first pressure stage. The first pressure stage is used to increase the clutch pressure based on a target calibration time. When the target pressure control stage is the second pressure stage, the module acquires a second engine torque, a second engine speed, and a second transmission speed. The second pressure stage is used to increase the clutch pressure based on the target pressure. When the target pressure control stage is the third pressure stage, the module acquires a third engine torque, a third engine speed, a third transmission speed, and a clutch torque. The third pressure stage is used to control clutch engagement, so that the engine torque output is transmitted to the transmission.

[0141] In one possible implementation, the determining module 602 is used to determine a first intermediate pressure based on the first engine torque, the first engine speed, and the first transmission speed when the target pressure control stage is the first pressure stage; to correct the first intermediate pressure based on the target correction coefficient to obtain a first compensation pressure; and to use the sum of the first compensation pressure and the first clutch critical pressure as the target clutch pressure.

[0142] In one possible implementation, the determining module 602 is used to determine a first ascending gradient pressure and a pre-controlled target pressure based on the second engine torque, the second engine speed, and the second transmission speed when the target pressure control stage is the second pressure stage; and to use the first ascending gradient pressure and the pre-controlled target pressure as the target clutch pressure.

[0143] In one possible implementation, the acquisition module 601 is used to acquire the target control time in response to the target pressure control stage being a first pressure stage; the device further includes a switching module for switching the target pressure control stage from the first pressure stage to a second pressure stage when the target control time is greater than or equal to the target calibration time.

[0144] In one possible implementation, the determining module 602 is used to determine the clutch torque-pressure characteristic pressure based on the clutch torque when the target pressure control stage is the third pressure stage; determine the second ascending gradient pressure based on the third engine torque, the third engine speed, and the third transmission speed; correct the second ascending gradient pressure based on the clutch torque-pressure characteristic pressure to obtain a second intermediate pressure; and use the second intermediate pressure as the target clutch pressure.

[0145] In one possible implementation, the acquisition module 601 is used to acquire the fourth engine speed, the fourth engine torque, and the transmission oil temperature when the start-stop state is the start state; the determination module 602 is used to determine a third intermediate pressure based on the fourth engine torque and the transmission oil temperature, and to determine a second compensation pressure based on the fourth engine speed and the transmission oil temperature; the sum of the third intermediate pressure and the second compensation pressure is used as the clutch control pressure; and the control module 603 is used to control the clutch based on the clutch control pressure.

[0146] In one possible implementation, the determining module 602 is used to determine a target filling time based on the fourth engine speed, the fourth engine torque, and the transmission oil temperature; the acquiring module 601 is used to acquire a filling control time in response to controlling the clutch based on the clutch control pressure, and to acquire a second clutch critical pressure if the filling control time is greater than or equal to the target filling time, the second clutch critical pressure being a calibration value related to the clutch type; and the controlling module 603 is used to control the clutch based on the second clutch critical pressure.

[0147] In one possible implementation, the determining module 602 is used to determine a base filling time based on the fourth engine torque and transmission oil temperature; determine a filling compensation time based on the fourth engine speed and transmission oil temperature; and use the sum of the base filling time and the filling compensation time as the target filling time.

[0148] It should be noted that the clutch control device provided in the above embodiments is only illustrated by the division of the above functional modules when controlling a vehicle. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the computer equipment can be divided into different functional modules to complete all or part of the functions described above. In addition, the clutch control device and the clutch control method embodiments provided in the above embodiments belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0149] The technical solution provided in this application, in response to the engine's automatic start-stop function being activated, and when the acquired start-stop state is the target state, acquires relevant parameters for the target pressure control stage corresponding to the target state. Then, based on these parameters, the target clutch pressure is determined in multiple consecutive target pressure control stages. The clutch is controlled based on the target clutch pressure, replacing the slip control process with a segmented pressure control method. This avoids drivability issues that arise during slip control, comprehensively improving the vehicle's driving experience. Furthermore, clutch pressure can be quickly provided in different pressure control stages, eliminating the need to limit engine input torque during start-up and improving overall vehicle starting power. Simultaneously, segmented continuous pressure control enables slip-free control of the gear clutch, reducing clutch slippage during start-up, extending the service life of related components, and improving the smoothness and driving comfort during automatic start-stop restart.

[0150] This application also provides a vehicle. Figure 7 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application.

[0151] Typically, vehicle 700 includes one or more processors 701 and one or more memories 702.

[0152] Processor 701 may include one or more processing cores, such as a quad-core processor, a hexa-core processor, etc. Processor 701 may be implemented using at least one hardware form selected from DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). Processor 701 may also include a main processor and a coprocessor. The main processor, also known as a CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, processor 701 may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, processor 701 may also include an AI (Artificial Intelligence) processor, which is used to handle computational operations related to machine learning.

[0153] The memory 702 may include one or more computer-readable storage media, which may be non-transitory. The memory 702 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In some embodiments, the non-transitory computer-readable storage media in the memory 702 are used to store at least one computer program, which is executed by the processor 701 to implement the clutch control method provided in the method embodiments of this application.

[0154] Those skilled in the art will understand that Figure 7 The structure shown does not constitute a limitation on vehicle 700 and may include more or fewer components than shown, or combine certain components, or use different component arrangements.

[0155] In addition, the device provided in the embodiments of this application may specifically be a chip, component or module. The chip may include a connected processor and a memory. The memory is used to store instructions. When the processor calls and executes the instructions, the chip can execute a clutch control method provided in the above embodiments.

[0156] This embodiment also provides a computer-readable storage medium storing computer program code. When the computer program code is run on a computer, the computer executes the above-described related method steps to implement a clutch control method provided in the above embodiment.

[0157] This embodiment also provides a computer program product that, when run on a computer, causes the computer to perform the aforementioned steps to implement a clutch control method provided in the above embodiment.

[0158] In this embodiment, the device, computer-readable storage medium, computer program product, or chip are all used to execute the corresponding methods provided above. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects in the corresponding methods provided above, and will not be repeated here.

[0159] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0160] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another apparatus, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0161] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for controlling a clutch, characterized in that, The method includes: In response to the engine's automatic start-stop function being activated, the start-stop status of the engine is obtained; When the start-stop state is the target state, the relevant parameters of the target pressure control stage corresponding to the target state are obtained. The target state is located after the start state and before the operation state. The target pressure control stage includes multiple consecutive pressure stages. The target clutch pressure is determined based on the relevant parameters, and the clutch is controlled based on the target clutch pressure. The upward trend of the target clutch pressure corresponding to the multiple consecutive pressure stages is different.

2. The method according to claim 1, characterized in that, The plurality of consecutive pressure stages include a first pressure stage, a second pressure stage, and a third pressure stage. The acquisition of relevant parameters for the target pressure control stage corresponding to the target state includes: When the target pressure control stage is the first pressure stage, the target correction coefficient, the first clutch critical pressure, the first engine torque, the first engine speed, and the first transmission speed are obtained. The first pressure stage is used to increase the clutch pressure based on the target calibration time. When the target pressure control phase is the second pressure phase, the second engine torque, the second engine speed and the second transmission speed are obtained, and the second pressure phase is used to increase the clutch pressure based on the target pressure. When the target pressure control stage is the third pressure stage, the third engine torque, the third engine speed, the third transmission speed, and the clutch torque are acquired. The third pressure stage is used to control the clutch engagement so that the engine torque output is transmitted to the transmission.

3. The method according to claim 2, characterized in that, Determining the target clutch pressure based on the relevant parameters includes: When the target pressure control stage is the first pressure stage, a first intermediate pressure is determined based on the first engine torque, the first engine speed, and the first transmission speed. The first intermediate pressure is corrected based on the target correction coefficient to obtain the first compensation pressure; The sum of the first compensation pressure and the first clutch critical pressure is taken as the target clutch pressure.

4. The method according to claim 2, characterized in that, Determining the target clutch pressure based on the relevant parameters includes: When the target pressure control phase is the second pressure phase, the first ascending gradient pressure and the pre-controlled target pressure are determined based on the second engine torque, the second engine speed, and the second transmission speed. The first ascending gradient pressure and the pre-controlled target pressure are used as the target clutch pressure.

5. The method according to claim 2, characterized in that, The method further includes: In response to the target pressure control stage being the first pressure stage, the target control time is obtained; If the target control time is greater than or equal to the target calibration time, the target pressure control stage is switched from the first pressure stage to the second pressure stage.

6. The method according to claim 2, characterized in that, Determining the target clutch pressure based on the relevant parameters includes: When the target pressure control stage is the third pressure stage, the clutch torque-pressure characteristic pressure is determined based on the clutch torque. The second ascending gradient pressure is determined based on the torque of the third engine, the speed of the third engine, and the speed of the third transmission. The second ascending gradient pressure is corrected based on the clutch torque-pressure characteristic to obtain the second intermediate pressure; The second intermediate pressure is taken as the target clutch pressure.

7. The method according to any one of claims 1 to 6, characterized in that, The method further includes: When the start-stop state is the start state, the fourth engine speed, the fourth engine torque, and the transmission oil temperature are obtained; A third intermediate pressure is determined based on the torque of the fourth engine and the transmission oil temperature, and a second compensation pressure is determined based on the speed of the fourth engine and the transmission oil temperature. The sum of the third intermediate pressure and the second compensation pressure is used as the clutch control pressure; The clutch is controlled based on the clutch control pressure.

8. The method according to claim 7, characterized in that, The method further includes: The target filling time is determined based on the speed of the fourth engine, the torque of the fourth engine, and the transmission oil temperature. In response to controlling the clutch based on the clutch control pressure, an oil filling control time is obtained; When the oil filling control time is greater than or equal to the target oil filling time, the second clutch critical pressure is obtained, and the second clutch critical pressure is a calibration value related to the type of clutch. The clutch is controlled based on the critical pressure of the second clutch.

9. The method according to claim 8, characterized in that, The determination of the target oil filling time based on the fourth engine speed, the fourth engine torque, and the transmission oil temperature includes: The base filling time is determined based on the torque of the fourth engine and the transmission oil temperature; The oil filling compensation time is determined based on the speed of the fourth engine and the transmission oil temperature; The sum of the base filling time and the filling compensation time is taken as the target filling time.

10. A vehicle, characterized in that, The vehicles include: Memory, used to store executable program code; A processor for calling and running the executable program code from the memory, causing the vehicle to perform the method as described in any one of claims 1 to 9.

Images