Clutch control method and device in vehicle on-gear sliding process and electronic equipment

Abstract

The invention discloses a clutch control method and device in the vehicle in-gear sliding process and electronic equipment, after a vehicle enters in-gear sliding, from the moment after fuel cut-off of an engine to the moment when the engine starts to recover fuel supply, the torque of a clutch is transited from the torque during sliding friction control to the Lash torque during Lash control, and the torque of the clutch is converted into the Lash torque during Lash control. The Lash torque is a critical torque for the clutch to eliminate a transmission system gap and drive wheels to rotate from a static state when the vehicle is in the current state, so that in the subsequent process from starting oil supply recovery to the engine until oil supply recovery is completed, the change of the torque in the oil supply recovery process of the engine does not cause transmission system jerking any more, and the reliability of the vehicle is improved. The smoothness of the vehicle in the gear sliding process is greatly improved; and after oil supply recovery of the engine is completed, the torque of the clutch is recovered from the Lash torque during Lash control to the torque during sliding friction control, and the clutch control process of the vehicle in the gear sliding process is completed once.

Description

Technical Field

[0001] The present application relates to the technical field of clutch control, and in particular to a clutch control method, device and electronic equipment for a vehicle in a gear coasting process. Background Art

[0002] The coasting of a vehicle in gear is a condition in which the vehicle relies on inertia to glide forward in a certain gear. The coasting condition in gear is one of the most common conditions in the driving process of the vehicle, and it is also one of the conditions in which the drivability of the vehicle is most easily perceived. Specifically, when the vehicle is in the coasting condition in gear, the driver only needs to decelerate smoothly. If there is a setback during the coasting process, the driver will generally feel it, and the setbacks generated during the coasting process have a greater impact on the ride comfort and will cause relatively large customer complaints. In addition, in order to save fuel consumption, when the vehicle is coasting in gear, the engine often adopts the strategy of cutting off fuel and using the wheels to reverse the engine to run. However, when the vehicle speed is low, in order to prevent the engine from stalling due to reverse drag, the engine needs to resume fuel supply. In the process of resuming fuel supply from the cut-off state to the completion of the resumption of fuel supply, the engine torque will change greatly, and the power of the transmission system will be reversed, which is easy to cause setbacks. Summary of the invention

[0003] In order to solve the above technical problems, the embodiments of the present application provide a clutch control method, device and electronic device for a vehicle during gear coasting, so as to eliminate the stalling caused by the engine going from a fuel cut-off state to the beginning of restoring fuel supply until the completion of restoring fuel supply during gear coasting, and improve the smoothness of the vehicle during gear coasting.

[0004] To achieve the above objectives, the present application provides the following technical solutions:

[0005] A clutch control method for a vehicle in a gear coasting process, after the vehicle enters the gear coasting process, the engine is first in a fuel cut-off state, and then resumes fuel supply until the fuel supply is resumed, and the clutch control method for the vehicle in a gear coasting process includes:

[0006] From a moment after the engine is cut off from fuel supply to the moment when the engine starts to resume fuel supply, the clutch torque is transitioned from the torque under slip control to the Lash torque under Lash control, wherein the Lash torque is the critical torque for the clutch to eliminate the transmission system clearance and drive the wheels from static to rotation in the current state of the vehicle;

[0007] When the time for the engine to resume fuel supply is reached, the engine is resumed with fuel supply;

[0008] From the moment when the engine fuel supply resumption is completed, the clutch torque is restored from the Lash torque during Lash control to the torque during slip control.

[0009] Optionally, from a moment after the engine fuel is cut off to a moment before the engine starts to resume fuel supply, the clutch torque is transitioned from the torque during slip control to the Lash torque during Lash control, including:

[0010] Based on the current vehicle gear, engine speed and vehicle acceleration, identifying the start time of clutch torque adjustment, the start time being before the engine starts to resume fuel supply;

[0011] From the starting time to the time when the engine starts to resume fuel supply, the clutch torque is transitioned from the torque during slip control to the Lash torque during Lash control.

[0012] Optionally, based on the current vehicle gear, engine speed and vehicle acceleration, identifying the start time of clutch torque adjustment includes:

[0013] Based on the current gear of the vehicle, when the engine speed is less than the preset speed corresponding to the current gear of the vehicle, and / or when the absolute value of the vehicle acceleration is less than the absolute value of the preset acceleration corresponding to the current gear of the vehicle, it is identified as the starting time of the clutch torque adjustment, the preset speed is greater than the engine speed when the engine starts to resume fuel supply in the current gear, and the absolute value of the preset acceleration is greater than the absolute value of the vehicle acceleration when the engine starts to resume fuel supply in the current gear.

[0014] Optionally, from the starting moment to the moment when the engine starts to resume fuel supply, the clutch torque is transitioned from the torque during slip control to the Lash torque during Lash control, including:

[0015] From the starting moment to the moment when the engine starts to resume fuel supply, the clutch torque is transitioned from the torque during slip control to the Lash torque during Lash control at a first rate and then at a second rate, and the first rate is greater than the second rate.

[0016] Optionally, the Lash torque is determined as follows:

[0017] Based on the current state of the vehicle and the pre-set correspondence between the vehicle state and the Lash torque, the Lash torque corresponding to the current state of the vehicle is determined. The correspondence is determined based on the Lash torque during clutch Lash control obtained by simulation or measurement under different vehicle states. The vehicle state includes the vehicle gear position, the vehicle temperature and the clutch speed.

[0018] Optionally, the process of determining the completion time of resuming fuel supply to the engine includes:

[0019] Based on the current vehicle gear and vehicle acceleration, the engine refueling completion time is identified.

[0020] Optionally, based on the current vehicle gear position and vehicle acceleration, identifying the completion time of resuming fuel supply to the engine includes:

[0021] Based on the current gear position of the vehicle, when the vehicle acceleration is greater than or equal to the vehicle acceleration at the time when the engine refueling is completed in the current gear position, it is identified as the time when the engine refueling is completed.

[0022] Optionally, starting from the moment when the engine resumes fuel supply, the clutch torque is restored from the Lash torque during Lash control to the torque during slipping control, including:

[0023] Starting from the moment when the engine resumes fuel supply, the speed difference between the current engine speed and the current clutch speed is used as the input of the closed-loop PID control algorithm, and the clutch torque during the clutch and engine slip control output by the closed-loop PID control algorithm is used as the target torque to control the clutch torque to transition from the Lash torque during Lash control to the target torque;

[0024] When the difference between the current torque of the clutch and the target torque is less than a set threshold, or when the time for controlling the clutch torque to transition to the target torque exceeds a set time, the clutch torque is restored from the Lash torque under Lash control to the torque under slip control.

[0025] A clutch control device for a vehicle in a gear coasting process, after the vehicle enters the gear coasting process, the engine is first in a fuel cut-off state, and then resumes fuel supply until the fuel supply is resumed, the clutch control device for the vehicle in a gear coasting process comprises:

[0026] The first control module is used to transition the clutch torque from the torque under slip control to the Lash torque under Lash control from a moment after the engine fuel is cut off to a moment before the engine starts to resume fuel supply, wherein the Lash torque is a critical torque for the clutch to eliminate the transmission system clearance and drive the wheels from static to rotation in the current state of the vehicle;

[0027] The second control module is used to resume fuel supply to the engine when the engine starts to resume fuel supply.

[0028] The third control module is used to restore the clutch torque from the Lash torque under Lash control to the torque under slip control starting from the moment when the engine resumes fuel supply.

[0029] An electronic device, comprising: a memory and a processor;

[0030] The memory is used to store programs;

[0031] The processor is used to execute the program to implement the various steps of the clutch control method of the vehicle during the coasting process as described in any one of the above items.

[0032] Compared with the prior art, the above technical solution has the following advantages:

[0033] The clutch control method of the vehicle during the coasting process in gear provided in the embodiment of the present application fully takes into account that after the vehicle enters the coasting state in gear, the engine is first in a fuel-cut state. At this time, the wheels reverse the engine to run, that is, the power transmission direction of the transmission system is from the wheels via the transmission and the clutch to the engine. The clutch transmits negative torque, and the engine torque is negative torque. From the beginning of the engine resuming fuel supply to the completion of the fuel supply resumption, the power transmission direction of the transmission system is reversed from the engine via the clutch and the transmission to the wheels. The engine torque changes from negative torque to zero torque or even positive torque, and the clutch changes from transmitting negative torque to transmitting positive torque, which can easily cause gear impact and cause frustration. Based on this, the clutch control method of the vehicle during the coasting process in gear provided in the embodiment of the present application transitions the clutch torque from the torque during sliding control to the Lash torque during Lash control from a moment after the engine is cut off from fuel to the moment before the engine starts to resume fuel supply. The torque is the critical torque for the clutch to eliminate the transmission system gap and drive the wheels from static to rotation in the current state of the vehicle. Therefore, in the subsequent process of resuming fuel supply to the engine until the resumption of fuel supply is completed, no matter how the engine torque changes, the power transmission direction from the clutch to the wheel is always from the clutch to the transmission and then to the wheel, and the upper limit of the positive torque transmitted is the Lash torque. Since the Lash torque is the critical torque for the clutch to eliminate the transmission system gap and drive the vehicle from static to rotation in the current state of the vehicle, the change of torque in the process of resuming fuel supply to the engine will no longer cause transmission system setbacks, greatly improving the smoothness of the vehicle in the process of gliding in gear; then, when the moment of resuming fuel supply to the engine is reached, the fuel supply to the engine is resumed; finally, starting from the moment when the engine resumes fuel supply, the clutch torque is restored from the Lash torque during Lash control to the torque during sliding control, completing a clutch control process of the vehicle in the process of gliding in gear. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1A schematic flow chart of a clutch control method for a vehicle in a coasting state provided by an embodiment of the present application;

[0036] Figure 2 Another schematic flow chart of a clutch control method for a vehicle in a coasting state provided by an embodiment of the present application;

[0037] Figure 3 A schematic diagram of another flow chart of a clutch control method during coasting of a vehicle in gear provided by an embodiment of the present application;

[0038] Figure 4 A flowchart of a clutch control method for a vehicle in a coasting state provided by an embodiment of the present application;

[0039] Figure 5 A schematic diagram of the structure of a clutch control device for a vehicle in a coasting state provided by an embodiment of the present application;

[0040] Figure 6 A hardware structure block diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0042] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0043] As mentioned in the background technology section, in order to save fuel consumption, the engine often cuts off fuel and uses the wheels to reverse the engine during the coasting process. However, when the vehicle speed is low, in order to prevent the engine from stalling due to reverse drag, the engine needs to resume fuel supply. During the process of resuming fuel supply from the fuel cut-off state to the completion of the resumption of fuel supply, the engine torque will change significantly, and the power of the transmission system will be reversed, which is easy to cause the occurrence of setbacks.

[0044] In view of the above problems, the prior art mainly uses an engine controller (EMS) to control the change of engine torque through torque filtering. However, since the engine torque changes uncontrollably and randomly during the process from the oil cut-off state to the start of oil restoration and the completion of oil restoration, the engine torque changes are limited in improvement of the setback during the oil restoration process by only relying on the engine controller to control the engine torque change through torque filtering, and it is impossible to completely eliminate it. Moreover, the setback during the oil restoration process is caused by the clearance of the transmission system. Specifically, the existence of the gear clearance of the transmission pancake teeth causes gear impact during power reversal, resulting in setbacks. Although the engine torque change can be controlled by torque filtering using the engine controller, the clutch is always in a locked state during the oil restoration process. From the reverse drag of the wheel to the forward driving of the engine, the power transmission direction of the transmission system will still be reversed, and the clutch will still transmit the change of the engine torque to the transmission and the wheels, which will inevitably cause gear impact and setbacks.

[0045] In view of this, an embodiment of the present application provides a clutch control method for a vehicle in a coasting process. Figure 1 FIG. 1 is a flow chart showing a clutch control method for a vehicle in a coasting process provided by an embodiment of the present application, such as Figure 1 As shown, the clutch control method of the vehicle during the coasting process includes:

[0046] S100: From a moment after the engine is cut off from fuel supply to a moment before the engine starts to resume fuel supply, the clutch torque is transitioned from the torque under slip control to the Lash torque under Lash control, where the Lash torque is the critical torque for the clutch to eliminate the transmission system clearance and drive the wheels from static to rotating in the current state of the vehicle;

[0047] S200: When the time for the engine to resume fuel supply is reached, resume fuel supply to the engine;

[0048] S300: Starting from the moment when the engine oil supply is restored, the clutch torque is restored from the Lash torque during Lash control to the torque during slipping control.

[0049] It is understandable that after the vehicle enters the gear and coasts, in order to save fuel consumption, the engine is first in a fuel-off state. At this time, the wheels reverse the engine to run, that is, the power transmission direction of the transmission system is from the wheels through the transmission, the clutch and then to the engine, the clutch transmits negative torque, and the engine torque is negative torque. As the vehicle coasts in the gear, the vehicle speed becomes lower and lower. When the vehicle speed is low, in order to prevent the engine from stalling when it is reversed, the engine needs to resume fuel supply. From the beginning of the engine to the completion of the resumption of fuel supply, the power transmission direction of the transmission system is reversed from the engine through the clutch, the transmission and then to the wheels, the engine torque changes from negative torque to zero torque or even positive torque, and the clutch changes from transmitting negative torque to transmitting positive torque. In the prior art, during the entire process of the vehicle coasting in the gear, including the engine being in a fuel-off state, starting to resume fuel supply and completing the resumption of fuel supply, the clutch is always in a locked state, that is, the clutch tightly combines the engine and the transmission, and the transmission torque changes with the engine torque through the clutch, which is easy to cause setbacks.

[0050] It can also be understood that during normal driving, the clutch torque is the torque during slip control. During the slip control stage, the clutch controls the speed difference between the clutch speed and the engine speed within a small range through a closed-loop PID (Proportional, Integral, Differential) control algorithm to achieve micro-slip dynamic balance.

[0051] When the clutch is in the Lash (eliminating transmission system clearance) control stage, the clutch torque is the Lash torque, which is the critical torque for the clutch to eliminate transmission system clearance and drive the wheels from static to rotation in the current state of the vehicle, or in other words, the Lash torque is the torque when the clutch eliminates transmission system clearance and just drives the wheels to rotate but has not yet driven the wheels to rotate. At this time, although the clutch is also in a locked state, the clutch is relatively loosened under Lash control compared to the degree of engagement between the engine and the transmission under slip control. At this time, no matter how the engine torque changes, the power transmission direction from the clutch to the wheel is always from the clutch through the transmission to the wheel, and the upper limit of the positive torque transmitted by the clutch is the Lash torque. For example, if the clutch Lash torque is 10Nm, when the engine torque is less than 10Nm, for example, 3Nm, the positive torque transmitted by the clutch is also 3Nm, and when the engine torque is greater than 10Nm, for example, 12Nm, the positive torque transmitted by the clutch is 10Nm.

[0052] Therefore, the clutch control method of the vehicle in the process of coasting in gear provided by the embodiment of the present application transitions the clutch torque from the torque during slip control to the Lash torque during Lash control from a moment after the engine is cut off from fuel to the moment before the engine starts to resume fuel supply. Therefore, in the subsequent process of starting to resume fuel supply to the engine until the resumption of fuel supply is completed, no matter how the engine torque changes, the power transmission direction from the clutch to the wheel is always from the clutch to the transmission and then to the wheel, and the upper limit of the positive torque transmitted is the Lash torque. Since the Lash torque is the critical torque for the clutch to eliminate the transmission system clearance and drive the vehicle from static to rotation in the current state of the vehicle, the change of torque during the process of resuming fuel supply will no longer cause the transmission system to stutter, thereby greatly improving the smoothness of the vehicle in the process of coasting in gear. Then, when the engine starts to resume fuel supply, the engine is resumed. Finally, starting from the moment when the engine resumes fuel supply, the clutch torque is restored from the Lash torque during Lash control to the torque during slip control, completing a clutch control process of the vehicle in the process of coasting in gear.

[0053] In the embodiment of the present application, starting from any moment after the engine fuel is cut off and before the engine starts to resume fuel supply, the clutch torque can be transitioned from the torque during slip control to the Lash torque during Lash control. The present application does not limit the starting moment of the transition of the clutch torque from the torque during slip control to the Lash torque during Lash control to which moment after the engine fuel is cut off and before the engine starts to resume fuel supply.

[0054] In the embodiment of the present application, the clutch torque must be transitioned from the torque during sliding control to the Lash torque during Lash control before the engine starts to resume fuel supply. Otherwise, the clutch has not had time to enter Lash control and the engine has started to resume fuel supply, which may easily cause stalling problems.

[0055] From the above analysis, it can be seen that in the embodiment of the present application, the moment when the engine starts to resume fuel supply refers to the moment when the engine resumes fuel supply after the fuel cut-off and the engine torque starts to change from negative torque. The moment when the engine resumes fuel supply is completed refers to the moment when the engine torque changes from negative torque to positive torque that can drive the wheels to rotate in a positive direction after the engine resumes fuel supply, so that the vehicle can travel normally.

[0056] Optionally, in some embodiments of the present application, such as Figure 2 As shown, step S100, from a moment after the engine fuel is cut off to a moment before the engine starts to resume fuel supply, the clutch torque is transitioned from the torque during slip control to the Lash torque during Lash control, including:

[0057] S110: Based on the current vehicle gear position, engine speed and vehicle acceleration, identifying the starting time of clutch torque adjustment, the starting time being before the engine starts to resume fuel supply;

[0058] S120: From the starting time to the time when the engine starts to resume fuel supply, the clutch torque is transitioned from the torque during slip control to the Lash torque during Lash control.

[0059] It can be understood that when the vehicle is coasting in a certain gear, the engine speed becomes smaller and smaller, and the vehicle acceleration is a negative value, that is, the vehicle is decelerating. When the engine speed decreases to a certain value, and / or the absolute value of the vehicle acceleration decreases to a certain value, it can be considered that the engine needs to start resuming fuel supply, otherwise it may stall. As mentioned above, the starting time of adjusting the clutch torque from the torque during slip control to the Lash torque during Lash control is before the engine starts to resume fuel supply. Therefore, the starting time of the clutch torque adjustment can be identified based on the current vehicle gear, engine speed and vehicle acceleration. The starting time of the clutch torque adjustment is the starting time of adjusting the clutch torque from the torque during slip control to the Lash torque during Lash control, and the starting time of the clutch torque adjustment is before the engine starts to resume fuel supply. Furthermore, from the starting time to the time when the engine starts to resume fuel supply, the clutch torque is transitioned from the torque during slip control to the Lash torque during Lash control.

[0060] Optionally, step S110, based on the current vehicle gear, engine speed and vehicle acceleration, identifying the start time of clutch torque adjustment includes:

[0061] S111: Based on the current gear of the vehicle, when the engine speed is less than the preset speed corresponding to the current gear of the vehicle, and / or when the absolute value of the vehicle acceleration is less than the preset acceleration corresponding to the current gear of the vehicle, it is identified as the starting time of the clutch torque adjustment, the preset speed is greater than the engine speed when the engine starts to resume fuel supply in the current gear, and the absolute value of the preset acceleration is greater than the absolute value of the vehicle acceleration when the engine starts to resume fuel supply in the current gear.

[0062] As is known from the above, the starting moment of the clutch torque adjustment is before the moment when the engine starts to resume fuel supply, that is, the engine speed of the vehicle at the starting moment of the clutch torque adjustment in a certain gear is greater than the engine speed when the engine starts to resume fuel supply, and the absolute value of the acceleration of the vehicle at the starting moment of the clutch torque adjustment in a certain gear is greater than the acceleration when the engine starts to resume fuel supply. Therefore, the speed and acceleration can be preset, and the preset speed is greater than the engine speed of the vehicle at the moment when the engine starts to resume fuel supply in the current gear, and the absolute value of the preset acceleration is greater than the absolute value of the vehicle acceleration at the moment when the engine starts to resume fuel supply in the current gear. Furthermore, based on the current gear of the vehicle, when the engine speed is less than the preset speed corresponding to the current gear of the vehicle, and / or when the absolute value of the vehicle acceleration is less than the preset acceleration corresponding to the current gear of the vehicle, it is identified as the starting moment of the clutch torque adjustment.

[0063] Specifically, on the one hand, the control strategy of the engine controller on the engine can be understood, so as to understand the threshold values ​​of the engine speed and vehicle acceleration when the engine starts to resume fuel supply; on the other hand, during the vehicle development process, the vehicle can be tested and verified to determine the threshold values ​​of the engine speed and vehicle acceleration when the engine starts to resume fuel supply; further, the moment when the engine starts to resume fuel supply can be determined, as well as the starting moment of the clutch torque adjustment before the moment when the engine starts to resume fuel supply.

[0064] For example, when the vehicle gear is at 3rd gear or below, the engine speed is less than 1500r / min, and the vehicle output shaft speed acceleration is greater than -50rpm / s (that is, the absolute value of the vehicle acceleration is less than 50rpm / s), it can be considered that the starting time of clutch torque adjustment has been reached, and the clutch torque is transitioned from the torque during slip control to the Lash torque during Lash control, wherein 1500r / min is greater than the engine speed when the vehicle starts to resume fuel supply in the current gear, and the absolute value of -50rpm / s is greater than the absolute value of the vehicle acceleration when the vehicle starts to resume fuel supply in the current gear.

[0065] Based on the above embodiment, optionally, step S120, from the starting moment to the moment when the engine starts to resume fuel supply, transitioning the clutch torque from the torque under slip control to the Lash torque under Lash control, includes:

[0066] S121: From the starting moment to the moment when the engine starts to resume fuel supply, the clutch torque is transitioned from the torque during slip control to the Lash torque during Lash control at a first rate and then at a second rate, and the first rate is greater than the second rate.

[0067] Specifically, starting from the starting moment, the torque of the clutch at the current moment is identified, and then the clutch torque is firstly transferred to the Lash torque during Lash control at a first rate and then at a second rate, the first rate being greater than the second rate, that is, the clutch torque is dynamically transferred to the Lash torque during Lash control in a first fast and then slow manner. This is because, when the clutch torque is just beginning to be adjusted, since the difference between the clutch torque and the Lash torque is large, the clutch torque can be adjusted at a faster first rate, thereby speeding up the response, and then the clutch torque is transferred to the Lash torque during Lash control at a slower second rate, thereby avoiding unnecessary impact or noise.

[0068] For example, at the starting moment, the clutch torque is 50Nm and the Lash torque is 10Nm. During the transition control process of the clutch torque from 50Nm to 10Nm, the change rate can be a dynamically changing value, first at a faster first rate and then at a slower second rate.

[0069] Optionally, in other embodiments of the present application, in step S120, from the starting moment to the moment when the engine starts to resume fuel supply, the clutch torque can be transitioned from the torque during slip control to the Lash torque during Lash control at a fixed rate, and the clutch torque can be transitioned from the torque during slip control to the Lash torque during Lash control at a third rate and then at a fourth rate, the third rate being lower than the fourth rate, and the clutch torque can be transitioned from the torque during slip control to the Lash torque during Lash control at other different rate methods.

[0070] Based on any of the above embodiments, optionally, the process of determining the Lash torque is:

[0071] S400: Determine the Lash torque corresponding to the current state of the vehicle based on the current state of the vehicle and the pre-set correspondence between the vehicle state and the Lash torque. The correspondence is determined based on the Lash torque of the clutch Lash control obtained by simulation or measurement under different vehicle states. The vehicle state includes the vehicle gear position, the vehicle temperature and the clutch speed.

[0072] It is understandable that the Lash torque of the vehicle is different when it is in different states. During the vehicle development process, the Lash torque of the clutch during Lash control can be obtained through simulation or actual vehicle measurement based on different vehicle states, thereby obtaining the correspondence between the vehicle state and the Lash torque. Furthermore, when it is necessary to transition the clutch torque from the torque during slip control to the Lash torque during Lash control, the Lash torque corresponding to the current state of the vehicle can be determined based on the current state of the vehicle and the pre-set correspondence between the vehicle state and the Lash torque, so as to facilitate the transition of the clutch torque from the torque during slip control to the Lash torque during Lash control.

[0073] Specifically, the vehicle state includes the vehicle gear position, the vehicle temperature and the clutch speed. When the Lash torque during clutch Lash control is obtained by simulation or actual vehicle measurement based on the different vehicle states, the Lash torque can be dynamically corrected, including clutch speed modification, vehicle gear correction and temperature correction, etc. Different corrections are used according to different vehicle matching. Through actual vehicle tests at different clutch speeds, different vehicle gears and different temperatures, the specific correction value of the Lash torque can be verified and adjusted, so that the Lash torque during clutch Lash control under different vehicle states can be more accurate.

[0074] It should be noted that the process of determining the Lash torque in step S400 can be performed simultaneously with step S100 or before step S100, depending on the specific circumstances.

[0075] As is known from the foregoing, in step S300, starting from the moment when the engine resumes fuel supply, the clutch torque is restored from the Lash torque under Lash control to the torque under slip control. Further optionally, the process of determining the moment when the engine resumes fuel supply includes:

[0076] S500: Based on the current vehicle gear position and vehicle acceleration, identify the time when the engine fuel supply resumption is completed.

[0077] It can be understood that the engine goes from fuel cut-off to fuel resumption until fuel resumption is complete, that is, the engine goes from reverse to idle, and the feedback to the wheel end is that after the engine resumes fuel supply, the engine's reverse braking force is gone, the vehicle's acceleration will increase, and the extent of the increase in vehicle acceleration is related to the reverse torque and the vehicle gear position. The vehicle speed does not change significantly when idling. Therefore, the moment when the engine resumes fuel supply can be identified based on the current vehicle gear position and vehicle acceleration.

[0078] Similar to identifying the starting moment of clutch torque adjustment, on the one hand, the control strategy of the engine controller on the engine can be understood, so as to understand the threshold value of the vehicle acceleration when the engine resumes fuel supply; on the other hand, during the vehicle development process, the vehicle can be tested and verified to determine the threshold value of the vehicle acceleration when the engine resumes fuel supply; further, the moment when the engine resumes fuel supply can be determined.

[0079] It should be noted that step S500 identifies the moment when the engine fuel supply is resumed after step S200, and after identifying the moment when the engine fuel supply is resumed, that is, starting from the moment when the engine fuel supply is resumed, step S300 is executed to restore the clutch torque from the Lash torque under Lash control to the torque under sliding friction control.

[0080] Specifically, step S500, based on the current vehicle gear position and vehicle acceleration, identifies the engine refueling completion time, including:

[0081] S510: Based on the current gear position of the vehicle, when the vehicle acceleration is greater than or equal to the vehicle acceleration at the time when the engine fuel supply is resumed in the current gear position, it is identified as the time when the engine fuel supply is resumed.

[0082] For example, when the vehicle gear exceeds 3rd gear and the vehicle output shaft speed acceleration is greater than -20rpm / s, it can be considered that the engine fuel supply resumption is complete.

[0083] Optionally, in some embodiments of the present application, such as Figure 3 As shown, step S300, starting from the moment when the engine resumes fuel supply, restores the clutch torque from the Lash torque during Lash control to the torque during slipping control, including:

[0084] S310: starting from the moment when the engine resumes fuel supply, the speed difference between the current engine speed and the current clutch speed is used as the input of the closed-loop PID control algorithm, and the clutch torque during the clutch and engine slip control output by the closed-loop PID control algorithm is used as the target torque, and the clutch torque is controlled to transition from the Lash torque during Lash control to the target torque;

[0085] S320: When the difference between the current torque of the clutch and the target torque is less than a set threshold, or when the time for controlling the clutch torque to transition to the target torque exceeds a set time, the clutch torque is restored from the Lash torque under Lash control to the torque under slip control.

[0086] As mentioned above, during normal driving, the clutch is under slip control. The clutch controls the speed difference between the clutch speed and the engine speed within a small range through a closed-loop PID control algorithm to achieve micro-slip dynamic balance. After the engine resumes fuel supply, the clutch torque needs to be adjusted from the torque during Lash control back to the torque during slip control. Under Lash control, the clutch does not consider the difference between the engine speed and the clutch speed. Therefore, starting from the moment when the engine resumes fuel supply, the speed difference between the current engine speed and the current clutch speed is used as the input of the closed-loop PID control algorithm, and the clutch torque during slip control of the clutch and the engine output by the closed-loop PID control algorithm is used as the target torque. The clutch torque is controlled to transition from the Lash torque during Lash control to the target torque, thereby smoothly transitioning the clutch torque from the torque during Lash control to the torque during slip control.

[0087] Specifically, when the clutch is under slip control, the speed difference Slip between the clutch speed and the engine speed is calculated. Assuming that the target speed difference of micro slip is 20rpm, that is, the speed difference Slip between the clutch speed and the engine speed under closed-loop control is around 20rpm, that is, to achieve Slip-20=0rpm, the adjustment is achieved by controlling the pressure of the clutch. For example, when Slip>20rpm, the error of Slip-20 is used as the closed-loop adjustment target to increase the clutch pressure; when Slip<20rpm, the error of Slip-20 is used as the closed-loop adjustment target to reduce the clutch pressure; if Slip=20rpm, the current clutch pressure is maintained.

[0088] Optionally, when the difference between the current torque of the clutch and the target torque is less than a set threshold, for example, the threshold may be 2Nm-5Nm, it can be considered that the clutch torque is restored from the Lash torque under Lash control to the torque under slip control.

[0089] Alternatively, when the time for controlling the clutch torque to transition to the target torque exceeds a set time, it can be considered that the clutch torque has been restored from the Lash torque during Lash control to the torque during slip control, which is timeout protection.

[0090] In summary, reference Figure 4The flowchart shown in the flowchart shows the clutch control method during the in-gear coasting process provided by the embodiment of the present application. When the vehicle enters the in-gear coasting state, the engine is in the fuel cut-off state, and the clutch is in the slip control state at this time; after identifying the starting time of the clutch torque adjustment, and before the engine starts to resume fuel supply, the clutch torque is transitioned from the torque during slip control to the Lash torque during Lash control, that is, the clutch changes to Lash control; thereafter, when the engine starts to resume fuel supply, the engine is resumed with fuel supply; further, after identifying the completion time of the engine resumption of fuel supply, starting from the completion time of the engine resumption of fuel supply, the clutch torque is restored from the Lash torque during Lash control to the torque during slip control, that is, the clutch is restored to slip control. Since the clutch is in the Lash control state, the change of torque during the process of resuming fuel supply of the engine will no longer cause the transmission system to stall, and therefore, the smoothness of the vehicle during the in-gear coasting process is greatly improved.

[0091] The present application also provides a clutch control device for a vehicle in a coasting process, such as Figure 5 As shown, the clutch control device 100 of the vehicle during the coasting process includes:

[0092] The first control module 10 is used to transition the clutch torque from the torque under slip control to the Lash torque under Lash control from a moment after the engine fuel is cut off to a moment before the engine starts to resume fuel supply, wherein the Lash torque is a critical torque for the clutch to eliminate the transmission system clearance and drive the wheels from static to rotation in the current state of the vehicle;

[0093] The second control module 20 is used to resume fuel supply to the engine when the engine starts to resume fuel supply;

[0094] The third control module 30 is used for restoring the clutch torque from the Lash torque under Lash control to the torque under slipping control starting from the moment when the engine resumes fuel supply.

[0095] Since the clutch control device 100 of the vehicle during the gear coasting process corresponds to the clutch control method of the vehicle during the gear coasting process mentioned above, and the various steps of the clutch control method of the vehicle during the gear coasting process provided by the embodiment of the present application have been discussed in detail above, they will not be repeated here.

[0096] An embodiment of the present application also provides an electronic device, which may be a server, a PC, a PAD, a mobile phone, an ECU (Electronic Control Unit), a VCU (Vehicle Control Unit), an MCU (Micro Controller Unit), an HCU (Hybrid Control Unit), etc.

[0097] Optional, Figure 6 The hardware structure diagram of the electronic device is shown in FIG. Figure 6 As shown, the electronic device may include: at least one processor 1, at least one communication interface 2, at least one memory 3 and at least one communication bus 4;

[0098] In the embodiment of the present application, the number of the processor 1, the communication interface 2, the memory 3, and the communication bus 4 is at least one, and the processor 1, the communication interface 2, and the memory 3 communicate with each other through the communication bus 4;

[0099] The processor 1 may be a central processing unit CPU, or an application-specific integrated circuit ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present invention, etc.;

[0100] The memory 3 may include a high-speed RAM memory, and may also include a non-volatile memory, such as at least one disk memory;

[0101] The memory stores a program, and the processor can call the program stored in the memory, wherein the program is used to:

[0102] From a moment after the engine is cut off from fuel supply to the moment when the engine starts to resume fuel supply, the clutch torque is transitioned from the torque under slip control to the Lash torque under Lash control, wherein the Lash torque is the critical torque for the clutch to eliminate the transmission system clearance and drive the wheels from static to rotation in the current state of the vehicle;

[0103] When the time for the engine to resume fuel supply is reached, the engine is resumed with fuel supply;

[0104] From the moment when the engine fuel supply resumption is completed, the clutch torque is restored from the Lash torque during Lash control to the torque during slip control.

[0105] The detailed and extended functions of the program can be found in the above description and will not be elaborated here.

[0106] The embodiment of the present application further provides a storage medium, which may store a program suitable for execution by a processor, wherein the program is used to:

[0107] From a moment after the engine is cut off from fuel supply to the moment when the engine starts to resume fuel supply, the clutch torque is transitioned from the torque under slip control to the Lash torque under Lash control, wherein the Lash torque is the critical torque for the clutch to eliminate the transmission system clearance and drive the wheels from static to rotation in the current state of the vehicle;

[0108] When the time for the engine to resume fuel supply is reached, the engine is resumed with fuel supply;

[0109] From the moment when the engine fuel supply resumption is completed, the clutch torque is restored from the Lash torque during Lash control to the torque during slip control.

[0110] The detailed and extended functions of the program can be found in the above description and will not be described in detail here.

[0111] The various parts in this manual are described in a combination of parallel and progressive ways. Each part focuses on the differences from other parts, and the same or similar parts between the various parts can be referenced to each other.

[0112] With respect to the above description of the disclosed embodiments, the features described in the embodiments in this specification may be replaced or combined with each other, so that professionals in the field can implement or use the present application. Various modifications to these embodiments will be apparent to professionals in the field, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A clutch control method for a vehicle in a gear coasting process, after the vehicle enters the gear coasting process, the engine is first in a fuel cut-off state, and then resumes fuel supply until the fuel supply is resumed. It is characterized in that The clutch control method of the vehicle during the coasting process includes: From a moment after the engine is cut off from fuel supply to the moment when the engine starts to resume fuel supply, the clutch torque is transitioned from the torque under slip control to the Lash torque under Lash control, wherein the Lash torque is the critical torque for the clutch to eliminate the transmission system clearance and drive the wheels from static to rotation in the current state of the vehicle; When the time for the engine to resume fuel supply is reached, the engine is resumed with fuel supply; From the moment when the engine fuel supply resumption is completed, the clutch torque is restored from the Lash torque during Lash control to the torque during slip control.

2. The clutch control method of a vehicle in a coasting state according to claim 1, It is characterized in that From a moment after the engine is cut off from fuel supply to the moment when the engine starts to resume fuel supply, the clutch torque is transitioned from the torque under slip control to the Lash torque under Lash control, including: Based on the current vehicle gear, engine speed and vehicle acceleration, identifying the start time of clutch torque adjustment, the start time being before the engine starts to resume fuel supply; From the starting time to the time when the engine starts to resume fuel supply, the clutch torque is transitioned from the torque during slip control to the Lash torque during Lash control.

3. The clutch control method of a vehicle in a coasting process according to claim 2, It is characterized in that Based on the current vehicle gear, engine speed and vehicle acceleration, identify the start time of clutch torque adjustment, including: Based on the current gear of the vehicle, when the engine speed is less than the preset speed corresponding to the current gear of the vehicle, and / or when the absolute value of the vehicle acceleration is less than the absolute value of the preset acceleration corresponding to the current gear of the vehicle, it is identified as the starting time of the clutch torque adjustment, the preset speed is greater than the engine speed when the engine starts to resume fuel supply in the current gear, and the absolute value of the preset acceleration is greater than the absolute value of the vehicle acceleration when the engine starts to resume fuel supply in the current gear.

4. The clutch control method of a vehicle in a coasting state according to claim 2, It is characterized in that From the starting time to the time when the engine starts to resume fuel supply, the clutch torque is transitioned from the torque under slip control to the Lash torque under Lash control, including: From the starting moment to the moment when the engine starts to resume fuel supply, the clutch torque is transitioned from the torque during slip control to the Lash torque during Lash control at a first rate and then at a second rate, and the first rate is greater than the second rate.

5. The clutch control method of a vehicle in a coasting process according to any one of claims 1 to 4, It is characterized in that The process of determining the Lash torque is as follows: Based on the current state of the vehicle and the pre-set correspondence between the vehicle state and the Lash torque, the Lash torque corresponding to the current state of the vehicle is determined. The correspondence is determined based on the Lash torque during clutch Lash control obtained by simulation or measurement under different vehicle states. The vehicle state includes the vehicle gear position, the vehicle temperature and the clutch speed.

6. The clutch control method of a vehicle in a coasting process according to claim 1, It is characterized in that The process of determining the completion time of resuming fuel supply to the engine includes: Based on the current vehicle gear and vehicle acceleration, the engine refueling completion time is identified.

7. The clutch control method of a vehicle in a coasting state according to claim 6, It is characterized in that Based on the current vehicle gear position and vehicle acceleration, identifying the completion time of resuming fuel supply to the engine includes: Based on the current gear position of the vehicle, when the vehicle acceleration is greater than or equal to the vehicle acceleration at the time when the engine refueling is completed in the current gear position, it is identified as the time when the engine refueling is completed.

8. The method for controlling the clutch of a vehicle in a coasting state according to claim 1, It is characterized in that From the moment when the engine resumes fuel supply, the clutch torque is restored from the Lash torque during Lash control to the torque during slip control, including: Starting from the moment when the engine resumes fuel supply, the speed difference between the current engine speed and the current clutch speed is used as the input of the closed-loop PID control algorithm, and the clutch torque during the clutch and engine slip control output by the closed-loop PID control algorithm is used as the target torque to control the clutch torque to transition from the Lash torque during Lash control to the target torque; When the difference between the current torque of the clutch and the target torque is less than a set threshold, or when the time for controlling the clutch torque to transition to the target torque exceeds a set time, the clutch torque is restored from the Lash torque under Lash control to the torque under slip control.

9. A clutch control device for a vehicle in a gear coasting process, after the vehicle enters the gear coasting process, the engine is first in a fuel cut-off state, and then resumes fuel supply until the fuel supply is resumed. It is characterized in that The clutch control device of the vehicle in the process of coasting comprises: The first control module is used to transition the clutch torque from the torque under slip control to the Lash torque under Lash control from a moment after the engine fuel is cut off to a moment before the engine starts to resume fuel supply, wherein the Lash torque is a critical torque for the clutch to eliminate the transmission system clearance and drive the wheels from static to rotation in the current state of the vehicle; The second control module is used to resume fuel supply to the engine when the engine starts to resume fuel supply. The third control module is used to restore the clutch torque from the Lash torque under Lash control to the torque under slip control starting from the moment when the engine resumes fuel supply.

10. An electronic device, It is characterized in that The electronic device comprises: a memory and a processor; The memory is used to store programs; The processor is used to execute the program to implement the various steps of the clutch control method of the vehicle during the coasting process as described in any one of claims 1-8.

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