Clutch control method for hill start of heavy-duty AMT vehicle

Abstract

The present invention relates to a clutch control method for starting a heavy-duty AMT vehicle on a hill, comprising the steps of: obtaining input conditions; executing a clutch fast idle stroke elimination phase; executing a clutch fast engagement phase; judging whether the clutch fast engagement phase is completed; executing a slipping and friction starting phase; performing a clutch engagement rate correction operation; judging whether the starting is completed; and terminating the process of the clutch control method for starting on a hill. The present invention enables the clutch to quickly reach a torque balance point, avoids vehicle slippage, and improves the starting response speed; enables the clutch to quickly reach a torque balance point, can significantly reduce clutch slippage, and improves the clutch life; effectively avoids the occurrence of starting failure problems, and improves the smoothness and starting speed of the starting process.

Description

Technical Field

[0001] The invention relates to the technical field of AMT control software development, and in particular to a clutch control method for a heavy-duty AMT vehicle hill start. Background Art

[0002] Compared with the traditional manual transmission (MT), the automatic mechanical transmission (AMT) has the advantages of simple operation, intelligent shifting, and a balance between power and fuel consumption. Compared with AT, it has the advantages of strong power, high transmission efficiency, fuel saving, low price, and low maintenance cost. It has become the main direction of the development of commercial vehicle transmissions in the future, and it is also an effective way to solve the problems of commercial vehicle fuel consumption, reduce component wear and improve driving safety.

[0003] On the other hand, due to the complex external driving environment of commercial vehicles and the diverse subjective intentions of drivers, the vehicle is a time-varying, nonlinear system with multiple inputs and outputs and many external interference factors, the development of AMT control strategies is more difficult. In terms of this technology, foreign technology is relatively mature, while domestic technology development is relatively weak. Moreover, the development of all control strategies at home and abroad is strictly confidential. Among them, start control is one of the core technologies of AMT control, and hill start control is one of the difficulties in AMT start control.

[0004] When a vehicle starts on a slope, it is necessary to consider both the starting response speed and the starting smoothness and speed. Therefore, this patent proposes an effective clutch control strategy to achieve the above control effect. Summary of the invention

[0005] In view of the above problems, the present invention provides a clutch control method for hill starting of heavy-duty AMT vehicles, which aims to enable the clutch to quickly reach a torque balance point, avoid slipping, and improve the starting response speed; enabling the clutch to quickly reach a torque balance point can significantly reduce clutch slippage and improve the life of the clutch; effectively avoid the occurrence of starting failure problems and improve the smoothness of the starting process and the starting speed.

[0006] To solve the above problems, the technical solution provided by the present invention is:

[0007] A method for controlling a clutch for starting a hill on a heavy-duty AMT vehicle comprises the following steps:

[0008] S100. Obtain input conditions;

[0009] S200. Execute the clutch to quickly eliminate the idle travel stage;

[0010] S300. Execute the clutch fast engagement stage;

[0011] S400. Determine whether the clutch quick engagement phase is completed; then perform the following operations according to the determination result:

[0012] If the judgment result is that the clutch quick engagement stage is finished, executing S500;

[0013] If the result of the determination is that the clutch quick engagement phase has not yet ended, the process returns to and executes S400 again;

[0014] S500. Execute the sliding start phase;

[0015] S600. Perform clutch engagement rate correction operation;

[0016] S700. Determine whether the start is completed; then perform the following operations according to the determination result:

[0017] If the judgment result is that the start is completed, then the process of the hill start clutch control method is terminated;

[0018] If the result of determination is that the start has not yet been completed, the process returns to and executes S500 again.

[0019] Preferably, the input conditions include: ramp, throttle opening, gear position, transmission input shaft speed, engine speed change rate, hill start assist, engine operating mode, and engine speed.

[0020] Preferably, the clutch quick elimination of idle travel stage in S200 specifically includes the following steps:

[0021] S210. Determine whether the vehicle is parked on a ramp; then perform the following operations based on the determination result:

[0022] If the judgment result is that the vehicle is parked on a slope, execute S220;

[0023] If the result of the determination is that the vehicle is not parked on a slope, the process returns to and executes S100 again;

[0024] S220. Determine whether the vehicle brakes are released; then perform the following operations based on the determination result:

[0025] If the result of the determination is that the vehicle has released the brakes, then S230 is executed;

[0026] If the result of the determination is that the vehicle has not released the brake, the process returns to and executes S220 again;

[0027] S230. The clutch reaches the first stop point; the first stop point is before the torque transmission point position, and the distance from the torque transmission point is offset according to the torque transmission point position learned by the clutch.

[0028] Preferably, the clutch quick engagement stage in S300 specifically includes the following steps:

[0029] S310. Check the throttle opening; then perform the following operations according to the check result:

[0030] If the throttle opening is greater than 0, execute S320;

[0031] If the throttle opening is equal to 0, return to and execute S310 again;

[0032] S320. Obtain the basic clutch engagement rate of the clutch in the clutch fast engagement stage according to the ramp and the gear table lookup; obtain the limited clutch engagement rate of the clutch in the clutch fast engagement stage according to the throttle opening;

[0033] S330. If the ramp value is less than the manually preset ramp threshold and the transmission input shaft speed exceeds the set threshold, and the clutch feedback torque also exceeds the set threshold, the basic clutch engagement rate of the clutch in the clutch fast engagement stage obtained in S320 and the limited clutch engagement rate of the clutch in the clutch fast engagement stage are compared and the smaller one is taken;

[0034] If it is detected that the hill start assist function is turned on, the smaller limit clutch engagement rate is multiplied by a manually preset correction coefficient to reduce the clutch engagement rate and obtain the final clutch engagement rate of the clutch in the clutch fast engagement stage;

[0035] S340. Adjust the clutch position according to the final clutch engagement rate of the clutch to achieve a vehicle drive-load torque balance point.

[0036] Preferably, determining whether the clutch quick engagement phase is completed in S400 specifically includes the following contents:

[0037] S410. Check whether the clutch quick engagement phase end condition is met; then perform the following operations according to the check result:

[0038] If the checking result is that the clutch quick engagement phase end condition is met, the judgment result of S400 is set as the clutch quick engagement phase end;

[0039] If the checking result is that the clutch quick engagement phase end condition is not satisfied, the judgment result of S400 is set as that the clutch quick engagement phase has not ended;

[0040] The clutch quick engagement phase end condition includes a first clutch engagement end condition, a second clutch engagement end condition, and a third clutch engagement end condition; wherein:

[0041] If at least one of the first clutch engagement termination condition, the second clutch engagement termination condition, and the third clutch engagement termination condition is satisfied, the inspection result may be set as the clutch rapid engagement phase termination condition being satisfied.

[0042] Preferably, the specific content of the first clutch engagement termination condition is: the transmission input shaft speed exceeds the manually preset transmission input shaft speed threshold for clutch engagement termination, and the clutch rapid engagement time exceeds the manually preset clutch rapid engagement termination clutch engagement minimum time threshold;

[0043] The specific content of the second clutch engagement termination condition is: the clutch rapid engagement time exceeds the manually preset maximum threshold value of the clutch rapid engagement termination start time;

[0044] The specific content of the third clutch engagement termination condition is: the clutch feedback torque exceeds a manually preset clutch engagement termination clutch feedback torque threshold.

[0045] Preferably, the sliding friction starting stage in S500 specifically includes the following steps:

[0046] S510. The clutch continues to be engaged until the vehicle starts to move;

[0047] The clutch engagement rate in the slippery start phase is obtained by calibration operations performed on the ramp, the throttle opening, and the gear position; the calibration operations include forward start calibration operations and reverse start calibration operations; specifically:

[0048] In the forward start calibration operation, the clutch engagement rate in the slippery start phase is calibrated according to the ramp, wherein: the ramp is positively correlated with the clutch engagement rate in the slippery start phase;

[0049] In the reverse start calibration operation, the clutch engagement rate in the slippery start phase is calibrated according to the throttle opening, wherein: the throttle opening is positively correlated with the clutch engagement rate in the slippery start phase.

[0050] Preferably, the clutch engagement rate correction operation in S600 includes an engine speed change rate correction operation, an engine speed correction operation, a gearbox input shaft speed correction operation, and an engine torque limit mode correction operation; wherein:

[0051] The engine speed change rate correction operation specifically includes the following steps:

[0052] Sa610 real-time monitoring of the engine speed change rate;

[0053] Sa620. According to the engine speed change rate table, determine a set of clutch engagement rate correction coefficients; specifically:

[0054] If the engine speed change rate is less than the manually preset engine speed change rate threshold, the correction coefficient is a value less than 1;

[0055] If the engine speed change rate is less than the manually preset engine speed change rate threshold, and the engine speed exceeds the set threshold, the correction coefficient is a value greater than 1;

[0056] Sa630. Use the clutch engagement rate correction coefficient to correct the clutch engagement rate;

[0057] The engine speed correction operation specifically includes the following steps:

[0058] Sb610. Get engine speed in real time;

[0059] Sb620. Compare the engine speed with the manually preset engine speed correction threshold; then perform the following operations based on the comparison result:

[0060] If the engine speed is below the engine speed correction threshold, reducing the clutch engagement rate;

[0061] If the engine speed is higher than the engine speed correction threshold, increasing the clutch engagement rate;

[0062] The input shaft speed correction operation specifically includes the following steps:

[0063] Sc610. Get the gearbox input shaft speed in real time;

[0064] If the input shaft speed is lower than the manually set threshold, the clutch engagement rate is multiplied by a correction coefficient greater than 1 to obtain a corrected clutch engagement rate;

[0065] Sc620. Execute the corrected clutch engagement rate;

[0066] Sd610. Real-time acquisition of engine control mode, ramp, throttle opening, engine speed, and transmission input shaft speed;

[0067] If it is detected that the engine has entered the torque limiting mode, the ramp exceeds a manually preset threshold, the throttle opening is lower than a manually preset threshold and the engine speed is lower than a manually preset first threshold, or the engine speed is lower than a manually preset second threshold, and the input shaft speed exceeds a manually preset threshold, the clutch engagement rate will be limited to a smaller manually preset value;

[0068] Sd620. Clutch engagement rate after execution limitation.

[0069] Preferably, the precondition for executing the throttle opening correction operation is:

[0070] The engine speed is higher than the manually preset throttle opening correction engine speed threshold, the engine is not torque limited, and the engine speed change rate exceeds the manually preset throttle opening correction engine speed change rate threshold.

[0071] Preferably, determining whether the start is completed in S700 specifically includes the following steps:

[0072] S710. Check whether the start-end condition is met; then perform the following operations according to the check result:

[0073] If the check result is that the start-end condition is satisfied, the determination result of S400 is set as the start-end;

[0074] If the check result is that the start-end condition is not satisfied, the determination result of S400 is set as that the start-up has not yet ended;

[0075] The start end condition includes a first start end condition, a second start end condition, and a third start end condition; wherein, only when the first start end condition, the second start end condition, and the third start end condition are satisfied at the same time, can the check result be set as the start end condition being satisfied;

[0076] The specific content of the first start end condition is: the speed difference between the engine speed and the clutch speed is lower than the set speed difference threshold and the duration is longer than the manually preset time threshold;

[0077] The specific content of the second start end condition is that the throttle opening exceeds the manually preset start end throttle opening threshold, or the engine speed exceeds the start end engine speed threshold;

[0078] The specific content of the third starting end condition is: the engine speed exceeds a manually preset minimum engine speed threshold.

[0079] Compared with the prior art, the present invention has the following advantages:

[0080] 1. Due to the fast engagement of the clutch in the fast engagement stage of the clutch, the clutch can quickly reach the torque balance point, avoid slipping, and improve the starting response speed;

[0081] 2. Due to the fast engagement of the clutch in the fast engagement stage of the clutch, the clutch can quickly reach the torque balance point, which can significantly reduce clutch slip and increase the life of the clutch;

[0082] 3. The present invention can effectively avoid the occurrence of starting failure problems and improve the smoothness and starting speed of the starting process by controlling the clutch slippage and correcting the engine speed change rate during the slippage starting stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 It is a logic diagram of hill start control according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0084] The present invention is further explained below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0085] A method for controlling a clutch for starting a hill on a heavy-duty AMT vehicle comprises the following steps:

[0086] S100. Obtain input conditions.

[0087] In this specific embodiment, the input conditions include: ramp, throttle opening, gear position, transmission input shaft speed, engine speed change rate, hill start assist, engine operating mode, and engine speed.

[0088] S200. Execute the clutch quick elimination of idle travel phase.

[0089] In this specific embodiment, the clutch quick elimination of idle travel stage in S200 specifically includes the following steps:

[0090] S210. Determine whether the vehicle is parked on a ramp; then perform the following operations based on the determination result:

[0091] If the determination result is that the vehicle is parked on a slope, S220 is executed.

[0092] If the result of determination is that the vehicle is not parked on a slope, the process returns to and executes S100 again.

[0093] S220. Determine whether the vehicle brakes are released; then perform the following operations based on the determination result:

[0094] If the result of determination is that the vehicle has released its brakes, S230 is executed.

[0095] If the result of determination is that the vehicle has not released the brakes, the process returns to and executes S220 again.

[0096] It should be noted that if Figure 1 As shown, point A corresponds to the beginning of the clutch quick elimination of idle travel phase. During this phase:

[0097] S230. The clutch reaches the first stop point; the first stop point is before the torque transmission point, and the distance from the torque transmission point is offset according to the torque transmission point position learned by the clutch.

[0098] It should be noted that, in S250, the clutch reaches the first stop point at the fastest speed.

[0099] It should be further explained that the control purpose of the clutch quick elimination of idle travel stage is to improve the throttle responsiveness when the accelerator is pressed during the clutch quick engagement stage to avoid slipping; Figure 1 Point B in the middle corresponds to the end position of the clutch's rapid elimination of idle travel phase, and is also the beginning position of the clutch's rapid engagement phase.

[0100] S300. Execute the clutch quick engagement phase.

[0101] In this specific embodiment, the clutch quick engagement stage in S300 specifically includes the following steps:

[0102] S310. Check the throttle opening; then perform the following operations based on the check result:

[0103] If the throttle opening is greater than 0, execute S320.

[0104] If the throttle opening is equal to 0, the process returns to and executes S310 again.

[0105] It should be noted that the meaning of S310 is that after pressing the accelerator, the clutch enters the fast engagement stage, that is, Figure 1 The position corresponding to point B in the middle.

[0106] S320. Obtain the basic clutch engagement rate of the clutch in the clutch fast engagement stage according to the ramp and gear table lookup; obtain the limited clutch engagement rate of the clutch in the clutch fast engagement stage according to the throttle opening;

[0107] S330. If the ramp value is less than the manually preset ramp threshold and the transmission input shaft speed exceeds the set threshold, and the clutch feedback torque also exceeds the set threshold, the basic clutch engagement rate of the clutch in the clutch fast engagement stage obtained in S320 and the limited clutch engagement rate of the clutch in the clutch fast engagement stage are compared and the smaller one is taken;

[0108] If it is detected that the hill start assist function is turned on, the smaller limited clutch engagement rate will be multiplied by an artificially preset correction coefficient to perform a reduction correction to reduce the clutch engagement rate and obtain the final clutch engagement rate of the clutch in the clutch rapid engagement stage.

[0109] It should be noted that the reason for the revision of S330 is to take into account the driving needs of the driver.

[0110] S340. Adjust the clutch position according to the final clutch engagement rate of the clutch to achieve the vehicle drive-load torque balance point.

[0111] It should be noted that the rapid clutch engagement stage requires the clutch to quickly reach the vehicle drive-load torque balance point to ensure that the vehicle does not slip after the brake is released.

[0112] S400. Determine whether the clutch quick engagement phase is completed; then perform the following operations according to the determination result:

[0113] If the result of determination is that the clutch quick engagement phase is completed, S500 is executed.

[0114] If the result of determination is that the clutch quick engagement phase has not yet ended, the process returns to and executes S400 again.

[0115] In this specific embodiment, determining whether the clutch quick engagement phase is completed in S400 specifically includes the following contents:

[0116] S410. Check whether the clutch quick engagement phase end condition is met; then perform the following operations according to the check result:

[0117] If the check result is that the clutch rapid engagement phase end condition is satisfied, the determination result of S400 is set as the clutch rapid engagement phase end.

[0118] If the checking result is that the clutch rapid engagement phase end condition is not satisfied, the determination result of S400 is set as that the clutch rapid engagement phase has not ended.

[0119] The clutch quick engagement phase end condition includes the first clutch engagement end condition, the second clutch engagement end condition, and the third clutch engagement end condition; wherein:

[0120] If at least one of the first clutch engagement termination condition, the second clutch engagement termination condition, and the third clutch engagement termination condition is satisfied, the inspection result may be set as the clutch rapid engagement phase termination condition being satisfied.

[0121] In this specific embodiment, the specific content of the first clutch engagement termination condition is: the transmission input shaft speed exceeds the manually preset transmission input shaft speed threshold for clutch engagement termination, and the clutch rapid engagement time exceeds the manually preset clutch rapid engagement termination clutch engagement minimum time threshold.

[0122] The specific content of the second clutch engagement termination condition is: the clutch rapid engagement time exceeds the manually preset clutch rapid engagement termination start maximum time threshold.

[0123] The specific content of the third clutch engagement termination condition is: the clutch feedback torque exceeds a manually preset clutch engagement termination clutch feedback torque threshold.

[0124] It should be noted that the main purpose of the clutch quick engagement stage is to allow the clutch to quickly reach a dynamic balance position to avoid slipping. However, if the clutch is engaged too deeply during the clutch quick engagement stage, it will cause starting impact problems. In severe cases, it may cause the engine to be dragged back and start failure. Therefore, the end conditions of the clutch quick engagement stage must be strictly defined; such as Figure 1 As shown in , point C is the end timing of the clutch rapid engagement stage.

[0125] S500: Execute the sliding start phase.

[0126] It should be noted that, at this stage, the torque transmitted gradually exceeds the resistance that needs to be overcome for the vehicle to start, and the vehicle starts to start.

[0127] In this specific embodiment, the sliding friction starting stage in S500 specifically includes the following steps:

[0128] S510. The clutch continues to engage until the vehicle starts to move.

[0129] The clutch engagement rate in the slippery start phase is obtained through calibration operations performed on the slope, throttle opening, and gear position; the calibration operations include forward start calibration operations and reverse start calibration operations; specifically:

[0130] In the forward start calibration operation, the clutch engagement rate in the slippery start phase is calibrated according to the ramp, wherein: the ramp is positively correlated with the clutch engagement rate in the slippery start phase.

[0131] In the reverse start calibration operation, the clutch engagement rate in the slippery start phase is calibrated according to the throttle opening, wherein the throttle opening is positively correlated with the clutch engagement rate in the slippery start phase.

[0132] It should be noted that the principle of the above calibration is that the greater the slope, the smaller the clutch engagement rate, and the greater the throttle, the lower the clutch engagement rate; when reversing, the calibration is performed according to the throttle opening, and the greater the throttle, the greater the clutch engagement rate. When starting forward, both starting speed and starting smoothness should be taken into account, and when reversing, both should be taken into account, but smoothness is the main consideration.

[0133] S600. Perform clutch engagement rate correction operation.

[0134] In this specific embodiment, the clutch engagement rate correction operation in S600 includes an engine speed change rate correction operation, an engine speed correction operation, a gearbox input shaft speed correction operation, and an engine torque limit mode correction operation; wherein:

[0135] The engine speed change rate correction operation specifically includes the following steps:

[0136] Sa610. Real-time monitoring of engine speed change rate.

[0137] Sa620. According to the engine speed change rate table, determine a set of clutch engagement rate correction coefficients; specifically:

[0138] If the engine speed change rate is less than the manually preset engine speed change rate threshold, the correction coefficient is a value less than 1;

[0139] If the engine speed change rate is less than a manually preset engine speed change rate threshold, and the engine speed exceeds the set threshold, the correction coefficient is a value greater than 1.

[0140] Sa630. Use the clutch engagement rate correction coefficient to correct the clutch engagement rate.

[0141] It should be noted that among all driving conditions, the engine load increases fastest during the starting process. Due to the influence of the engine's own performance and the surrounding environment, during the process of load increase, the engine speed may be dragged down due to the engine's insufficient low-speed torque capacity, which may lead to stalling at the start in severe cases. Therefore, during the starting process, during the clutch rapid engagement stage and the slipping stage, in order to ensure successful starting, the engine speed change rate must be monitored in real time, and the clutch engagement rate must be adjusted in real time according to the engine speed change. The adjustment method is to determine a set of correction coefficients based on the engine speed change rate to correct the clutch engagement rate; its main feature is that the smaller the engine speed change rate, the smaller the correction coefficient, that is, the lower the clutch engagement rate.

[0142] The engine speed correction operation specifically includes the following steps:

[0143] Sb610. Get engine speed in real time;

[0144] Sb620. Compare the engine speed with the manually preset engine speed correction threshold; then perform the following operations based on the comparison result:

[0145] If the engine speed is below the engine speed correction threshold, the clutch engagement rate is reduced.

[0146] If the engine speed is above the engine speed correction threshold, the clutch engagement rate is increased.

[0147] It should be noted that, as mentioned above, the torque capacity of the engine has a great influence on hill starting, so the engine speed must be detected at all times when starting on a hill, and the clutch engagement rate must be corrected according to the engine throttle characteristics. The correction method is: on a certain slope, if the engine speed is lower than a certain threshold and the engine torque itself is limited, the clutch engagement rate is reduced. If the engine speed exceeds a certain value and the engine speed change rate is also higher than a certain value, the clutch engagement rate is accelerated to speed up the starting speed and reduce the clutch slip time.

[0148] The input shaft speed correction operation specifically includes the following steps:

[0149] Sc610. Get the gearbox input shaft speed in real time;

[0150] If the input shaft speed is lower than the manually set threshold, the clutch engagement rate is multiplied by a correction coefficient greater than 1 to obtain a corrected clutch engagement rate.

[0151] Sc620. Execute the corrected clutch engagement rate.

[0152] Sd610. Real-time acquisition of engine control mode, ramp, throttle opening, engine speed, and transmission input shaft speed;

[0153] If it is detected that the engine has entered the torque limiting mode, the ramp exceeds a manually preset threshold, the throttle opening is lower than a manually preset threshold and the engine speed is lower than a manually preset first threshold, or the engine speed is lower than a manually preset second threshold, and the input shaft speed exceeds a manually preset threshold, the clutch engagement rate will be limited to a smaller manually preset value;

[0154] Sd620. Clutch engagement rate after execution limitation.

[0155] In this specific embodiment, the precondition for executing the throttle opening correction operation is:

[0156] The engine speed is higher than the manually preset throttle opening correction engine speed threshold, the engine is not torque limited, and the engine speed change rate exceeds the manually preset throttle opening correction engine speed change rate threshold.

[0157] It should be noted that the throttle opening size reflects the driver's driving needs. Under the conditions that the engine capacity allows, that is, the engine speed is higher than a certain threshold, the engine is not torque-limited, and the engine speed change rate exceeds a certain threshold, the throttle is increased and the clutch engagement rate is increased by multiplying it by a correction coefficient greater than 1.

[0158] S700. Determine whether the start is completed; then perform the following operations according to the determination result:

[0159] If the judgment result is that the start is completed, the process of the hill start clutch control method is ended.

[0160] If the result of determination is that the start has not yet been completed, the process returns to and executes S500 again.

[0161] In this specific embodiment, determining whether the start is completed in S700 specifically includes the following steps:

[0162] S710. Check whether the start-end condition is met; then perform the following operations according to the check result:

[0163] If the check result is that the start-up end condition is satisfied, the determination result of S400 is set as start-up end.

[0164] If the check result is that the start-up end condition is not satisfied, the determination result of S400 is set as that the start-up has not yet been completed.

[0165] The start end condition includes a first start end condition, a second start end condition, and a third start end condition; wherein, only when the first start end condition, the second start end condition, and the third start end condition are satisfied at the same time, can the check result be set as the start end condition being satisfied.

[0166] The specific content of the first start end condition is: the speed difference between the engine speed and the clutch speed is lower than the set speed difference threshold and the duration is higher than the manually preset time threshold.

[0167] The specific content of the second start end condition is that the throttle opening exceeds a manually preset start end throttle opening threshold, or the engine speed exceeds a start end engine speed threshold.

[0168] The specific content of the third start termination condition is: the engine speed exceeds a manually preset minimum engine speed threshold.

[0169] It should be noted that Figure 1 Point D in the figure corresponds to the starting and ending positions.

[0170] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0171] The disclosed embodiments are described above to enable any person skilled in the art to implement or use the present invention. Various modifications of these embodiments are obvious to those skilled in the art, and the general principles defined herein may also be applied to other embodiments without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0172] The above description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," is explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

[0173] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for controlling a clutch for a heavy-duty AMT vehicle starting on a hill, characterized in that: The following steps are involved: S100. Obtain input conditions; S200. Execute the clutch to quickly eliminate the idle travel stage; S300. Execute the clutch fast engagement stage; S400. Determine whether the clutch quick engagement phase is completed; then perform the following operations according to the determination result: If the judgment result is that the clutch quick engagement stage is finished, executing S500; If the result of the determination is that the clutch quick engagement phase has not ended, the process returns to and executes S400 again; S500. Execute the sliding start phase; S600. Perform clutch engagement rate correction operation; S700. Determine whether the start is completed; then perform the following operations according to the determination result: If the judgment result is that the start is completed, then the process of the hill start clutch control method is terminated; If the result of the determination is that the start has not yet been completed, the process returns to and executes S500 again; The input conditions include: ramp, throttle opening, gear position, transmission input shaft speed, engine speed change rate, hill start assist, engine operating mode, and engine speed; The clutch quick elimination of idle travel phase in S200 specifically includes the following steps: S210. Determine whether the vehicle is parked on a ramp; then perform the following operations based on the determination result: If the judgment result is that the vehicle is parked on a slope, execute S220; If the result of the determination is that the vehicle is not parked on a slope, the process returns to and executes S100 again; S220. Determine whether the vehicle brakes are released; then perform the following operations based on the determination result: If the result of the determination is that the vehicle has released the brakes, then S230 is executed; If the result of the determination is that the vehicle has not released the brake, the process returns to and executes S220 again; S230. The clutch reaches the first stop point; the first stop point is before the torque point position, and the distance from the torque point is offset according to the torque point position learned by the clutch; The clutch quick engagement stage in S300 specifically includes the following steps: S310. Check the throttle opening; then perform the following operations according to the check result: If the throttle opening is greater than 0, execute S320; If the throttle opening is equal to 0, return to and execute S310 again; S320. Obtain the basic clutch engagement rate of the clutch in the clutch fast engagement stage according to the ramp and the gear table lookup; obtain the limited clutch engagement rate of the clutch in the clutch fast engagement stage according to the throttle opening; S330. If the ramp value is less than the manually preset ramp threshold and the transmission input shaft speed exceeds the set threshold, and the clutch feedback torque also exceeds the set threshold, the basic clutch engagement rate of the clutch in the clutch fast engagement stage obtained in S320 and the limited clutch engagement rate of the clutch in the clutch fast engagement stage are compared and the smaller one is taken; If it is detected that the hill start assist function is turned on, the smaller limit clutch engagement rate is multiplied by a manually preset correction coefficient to reduce the clutch engagement rate and obtain the final clutch engagement rate of the clutch in the clutch fast engagement stage; S340. According to the final clutch engagement rate of the clutch, the clutch position is adjusted to reach the vehicle drive-load torque balance point; In S400, judging whether the clutch quick engagement phase is completed specifically includes the following contents: S410. Check whether the clutch quick engagement phase end condition is met; then perform the following operations according to the check result: If the checking result is that the clutch quick engagement phase end condition is met, the judgment result of S400 is set as the clutch quick engagement phase end; If the checking result is that the clutch quick engagement phase end condition is not satisfied, the judgment result of S400 is set as that the clutch quick engagement phase has not ended; The clutch quick engagement phase end condition includes a first clutch engagement end condition, a second clutch engagement end condition, and a third clutch engagement end condition; wherein: If at least one of the first clutch engagement end condition, the second clutch engagement end condition, and the third clutch engagement end condition is satisfied, the inspection result can be set as the clutch quick engagement phase end condition being satisfied; The specific content of the first clutch engagement termination condition is: the transmission input shaft speed exceeds the manually preset transmission input shaft speed threshold for clutch engagement termination, and the clutch rapid engagement time exceeds the manually preset clutch rapid engagement termination clutch engagement minimum time threshold; The specific content of the second clutch engagement termination condition is: the clutch rapid engagement time exceeds the manually preset maximum threshold value of the clutch rapid engagement termination start time; The specific content of the third clutch engagement termination condition is: the clutch feedback torque exceeds a manually preset clutch engagement termination clutch feedback torque threshold; The sliding friction starting stage in S500 specifically includes the following steps: S510. The clutch continues to be engaged until the vehicle starts to move; The clutch engagement rate in the slippery start phase is obtained by calibration operations performed on the ramp, the throttle opening, and the gear position; the calibration operations include forward start calibration operations and reverse start calibration operations; specifically: In the forward start calibration operation, the clutch engagement rate in the slippery start phase is calibrated according to the ramp, wherein: the ramp is positively correlated with the clutch engagement rate in the slippery start phase; In the reverse start calibration operation, the clutch engagement rate in the slippery start phase is calibrated according to the throttle opening, wherein: the throttle opening is positively correlated with the clutch engagement rate in the slippery start phase; The clutch engagement rate correction operation in S600 includes an engine speed change rate correction operation, an engine speed correction operation, a transmission input shaft speed correction operation, and an engine torque limit mode correction operation; wherein: The engine speed change rate correction operation specifically includes the following steps: Sa610 real-time monitoring of the engine speed change rate; Sa620. According to the engine speed change rate table, determine a set of clutch engagement rate correction coefficients; specifically: If the engine speed change rate is less than the manually preset engine speed change rate threshold, the correction coefficient is a value less than 1; If the engine speed change rate is less than the manually preset engine speed change rate threshold, and the engine speed exceeds the set threshold, the correction coefficient is a value greater than 1; Sa630. Use the clutch engagement rate correction coefficient to correct the clutch engagement rate; The engine speed correction operation specifically includes the following steps: Sb610. Get engine speed in real time; Sb620. Compare the engine speed with the manually preset engine speed correction threshold; then perform the following operations based on the comparison result: If the engine speed is below the engine speed correction threshold, reducing the clutch engagement rate; If the engine speed is higher than the engine speed correction threshold, increasing the clutch engagement rate; The input shaft speed correction operation specifically includes the following steps: Sc610. Get the gearbox input shaft speed in real time; If the input shaft speed is lower than the manually set threshold, the clutch engagement rate is multiplied by a correction coefficient greater than 1 to obtain a corrected clutch engagement rate; Sc620. Execute the corrected clutch engagement rate; Sd610. Real-time acquisition of engine control mode, ramp, throttle opening, engine speed, and transmission input shaft speed; If it is detected that the engine has entered the torque limiting mode, the ramp exceeds a manually preset threshold, the throttle opening is lower than a manually preset threshold and the engine speed is lower than a manually preset first threshold, or the engine speed is lower than a manually preset second threshold, and the input shaft speed exceeds a manually preset threshold, the clutch engagement rate will be limited to a manually preset value; Sd620. Clutch engagement rate after execution limitation.

2. The method for controlling a clutch for starting a hill on a heavy-duty AMT vehicle according to claim 1, characterized in that: Determining whether the start is completed in S700 specifically includes the following steps: S710. Check whether the start-end condition is met; then perform the following operations according to the check result: If the check result is that the start-end condition is satisfied, the determination result of S400 is set as the start-end; If the check result is that the start-end condition is not satisfied, the determination result of S400 is set as that the start-up has not yet ended; The start end condition includes a first start end condition, a second start end condition, and a third start end condition; wherein, only when the first start end condition, the second start end condition, and the third start end condition are satisfied at the same time, can the check result be set as the start end condition being satisfied; The specific content of the first start end condition is: the speed difference between the engine speed and the clutch speed is lower than the set speed difference threshold and the duration is longer than the manually preset time threshold; The specific content of the second start end condition is that the throttle opening exceeds the manually preset start end throttle opening threshold, or the engine speed exceeds the start end engine speed threshold; The specific content of the third starting end condition is: the engine speed exceeds a manually preset minimum engine speed threshold.

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