A control method for active protection function of clutch of manual transmission vehicle

Abstract

The present invention belongs to the technical field of clutch characteristics of manual transmission vehicles, and specifically provides a control method for the active protection function of the clutch of a manual transmission vehicle, comprising the following steps: obtaining vehicle condition information for entering the active protection function; determining the clutch active protection function state machine mode according to the obtained vehicle condition information; when entering the clutch active protection function mode, the chassis multi-function controller sends a message to the engine controller through the CAN line to control the engine output speed / torque limit; when the clutch active protection function is switched to a normal state, the chassis multi-function controller stops sending messages to the engine controller, the engine enters a normal driving mode, and outputs the clutch friction plate surface temperature at the same time. Actively send a speed / torque limit request to the engine ECU under suitable working conditions, so as to adjust the engine output speed and torque on the basis of ensuring power and smoothness, and realize the active protection function of the clutch.

Description

Technical Field

[0001] The present invention relates to the technical field of clutch characteristics of manual transmission vehicle models, and specifically provides a method for controlling an active protection function of a clutch of a manual transmission vehicle model. Background Art

[0002] At present, the maximum output torque of heavy-duty commercial vehicle engines is getting higher and higher, and is generally 2700Nm-3000Nm or even higher. However, clutch friction is limited by material properties and layout space. It is difficult to meet the rapid increase of torque. When the driver accelerates quickly, steps on the throttle, and releases the clutch quickly, the clutch is prone to severe wear and even clutch ablation, which can cause the vehicle to spontaneously combust.

[0003] In the prior art, the methods for clutch protection usually use mechanical means to enhance the clutch material properties, friction area, etc., or protect the clutch after it has been severely worn. The commonly used clutch protection of automatic transmission AMT system is based on the electronic control of AMT clutch operation, which can actively control the clutch engagement time and speed according to the engine speed, which is easy to implement.

[0004] The clutch operation of traditional manual transmission models is completely determined by the driver's arbitrariness, and the separation and tightening of the clutch are uncontrollable. At this time, directly limiting the engine speed or torque often causes the vehicle's power to weaken, the power output to be uneven, and the driving performance to deteriorate. Summary of the invention

[0005] The clutch operation of traditional manual transmission vehicles is completely determined by the driver's arbitrary pressing and releasing, and the separation and compression of the clutch are uncontrollable. At this time, directly limiting the engine speed or torque often causes the problems of weakened vehicle power, uneven power output, and poor driving performance. The present invention provides a control method for the active protection function of the clutch of a manual transmission vehicle.

[0006] The technical solution of the present invention provides a method for controlling the active protection function of the clutch of a manual transmission vehicle, comprising the following steps:

[0007] Obtain vehicle condition information for entering active protection functions;

[0008] Determine the clutch active protection function state machine mode based on the acquired vehicle condition information;

[0009] When the clutch active protection function mode is entered, the chassis multi-function controller sends a message to the engine controller via the CAN line to perform engine output speed / torque limit control;

[0010] When the clutch active protection function switches to normal state, the chassis multi-function controller stops sending messages to the engine controller, the engine enters normal driving mode, and outputs the clutch friction plate surface temperature at the same time.

[0011] The clutch active protection function of manual transmission models is developed based on the chassis multi-function controller, clutch wear position sensor, gear position sensor, CAN information interaction, and engine controller external torque coordination control function. According to driving needs, the chassis multi-function controller can actively send speed / torque limit requests to the engine controller under suitable working conditions, so as to adjust the engine output speed and torque on the basis of ensuring power and smoothness, realize the active protection function of the clutch, avoid clutch ablation, improve driving comfort, and reduce fuel consumption, which is suitable for large-scale promotion and application.

[0012] Further, the vehicle condition information includes engine speed, gear position of the transmission, speed difference between clutch driven disc speed and engine speed;

[0013] The steps of obtaining the speed difference between the clutch driven plate speed and the engine speed include:

[0014] Get the engine speed and the transmission output shaft speed;

[0015] The current gearbox gear position is obtained in real time through the gearbox gear position sensor;

[0016] According to the current gearbox gear position, the current gearbox transmission ratio is obtained by looking up the table;

[0017] The clutch driven disc speed is obtained by multiplying the current transmission ratio of the transmission by the transmission output shaft speed;

[0018] The speed difference is calculated as the difference between the clutch plate speed and the engine speed.

[0019] Use the transmission gear position sensor to obtain the accurate gear position in real time, and get the current speed ratio based on the transmission gear position. Multiply the current speed ratio by the transmission output shaft speed to get the transmission input shaft speed. The difference between the clutch driven plate speed and the engine speed is the speed difference that needs to be obtained. Here, the transmission input shaft speed is actually the clutch driven plate speed.

[0020] Furthermore, the step of obtaining the engine speed and the transmission output shaft speed includes:

[0021] Read the current vehicle speed, engine speed, and transmission output shaft speed from the vehicle CAN line.

[0022] Furthermore, the vehicle condition information also includes clutch pressing position and clutch real-time position;

[0023] The steps of obtaining the clutch pressing position and the clutch real-time position include:

[0024] The clutch wear position sensor is used to read the real-time position of the clutch. The minimum value of the clutch wear position sensor is the clutch pressing position, and this position is recorded as the initial point position.

[0025] Further, the step of determining the clutch active protection function state machine mode according to the acquired vehicle condition information includes:

[0026] When the gearbox is in the set gear range and the vehicle speed is less than the calibrated limit, the clutch active protection function state machine mode enters the active protection function preparation stage;

[0027] When the clutch pressure plate moves from the release stage to the tightening stage and the clutch tightening position reaches the contact point, the clutch active protection function state machine mode active protection function enters the speed limit mode;

[0028] When the clutch pressing position reaches the initial point, it enters the slow torque mode;

[0029] After entering the slow torque mode, when the clutch slow torque reaches the set percentage of the driver's pedal demand torque or the slow torque time exceeds the calibrated threshold, the clutch active protection function mode is exited and switched to the normal driving stage.

[0030] Furthermore, the method also includes:

[0031] If any gear position or vehicle speed exceeds the corresponding calibrated threshold during the preparation stage of the active protection function, the speed limit mode or the slow torque mode, the clutch active protection function will be directly exited.

[0032] Further, when the clutch active protection function mode is entered, the chassis multi-function controller sends a message to the engine controller through the CAN line to perform engine output speed / torque limit control. The step of the chassis multi-function controller sending a message to the engine controller through the CAN line to perform engine output speed limit control includes:

[0033] When the clutch active protection function enters the speed limit mode, the chassis multi-function controller sends a TSC1 message to the engine controller via the CAN line to limit the engine speed and make a ramp control output to limit the actual engine speed within the set threshold range.

[0034] Further, when the clutch active protection function mode is entered, in the step of the chassis multi-function controller sending a message to the engine controller through the CAN line to perform engine output speed / torque limit control, the step of the chassis multi-function controller sending a message to the engine controller through the CAN line to perform engine torque limit control includes:

[0035] When the clutch active protection function enters the slow torque mode, the chassis multi-function controller sends the TSC1 message to the engine ECU through the CAN line to limit the engine torque and make a ramp control output, gradually amplifying the actual engine torque from the current actual torque to the set percentage of the current torque output by the driver stepping on the accelerator, thereby completing the gradual increase of torque.

[0036] Through information such as gear position and clutch position, the engine can be automatically limited in speed and torque-reduced according to the working conditions. Without affecting drivability, the clutch can be actively protected to avoid excessive wear of the clutch, thus extending its service life and having high promotion value.

[0037] It can be seen from the above technical scheme that the present invention has the following advantages: according to driving needs, a speed / torque limit request can be actively sent to the engine ECU through the chassis multi-function controller under suitable working conditions, so as to adjust the engine output speed and torque on the basis of ensuring power and smoothness, realize the active protection function of the clutch, avoid clutch ablation, improve driving comfort, reduce fuel consumption, and is suitable for large-scale promotion and application.

[0038] In addition, the invention has a reliable design principle, a simple structure and a very broad application prospect.

[0039] It can be seen that compared with the prior art, the present invention has outstanding substantive features and significant progress, and the beneficial effects of its implementation are also obvious. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention 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, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 is a schematic flow chart of a method according to an embodiment of the present invention.

[0042] Figure 2 The figure is a schematic flow chart of the rotation speed difference calculation method according to an embodiment of the present invention.

[0043] Figure 3 It is a schematic diagram of active protection mode switching according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0045] like Figure 1 The present invention provides a method for controlling the active protection function of a clutch of a manual transmission vehicle, comprising the following steps:

[0046] Step 1: Obtain vehicle condition information for entering the active protection function;

[0047] Step 2: Determine the clutch active protection function state machine mode according to the acquired vehicle condition information;

[0048] Step 3: When entering the clutch active protection function mode, the chassis multi-function controller sends a message to the engine controller through the CAN line to perform engine output speed / torque limit control;

[0049] Step 4: When the clutch active protection function switches to normal state, the chassis multi-function controller stops sending messages to the engine controller, the engine enters normal driving mode, and outputs the clutch friction plate surface temperature at the same time.

[0050] It should be noted that the vehicle condition information includes vehicle speed, engine speed, gear position of the transmission, and the speed difference between the clutch driven disc speed and the engine speed;

[0051] like Figure 2 As shown, the step of obtaining the speed difference between the clutch driven plate speed and the engine speed includes:

[0052] Get the engine speed and the transmission output shaft speed;

[0053] The current gearbox gear position is obtained in real time through the gearbox gear position sensor;

[0054] According to the current gearbox gear position, the current gearbox transmission ratio is obtained by looking up the table;

[0055] The clutch driven disc speed is obtained by multiplying the current transmission ratio of the transmission by the transmission output shaft speed;

[0056] The speed difference is calculated as the difference between the clutch plate speed and the engine speed.

[0057] In the first step, the chassis multi-function controller reads the current engine speed and gearbox output shaft speed from the vehicle CAN line; the current gear is obtained after signal collection and processing from the gear sensor; the second step is to obtain the current transmission ratio of the gearbox according to the current gear of the gearbox; the third step is to calculate the clutch driven plate speed, clutch driven plate speed = gearbox input shaft speed = speed ratio * output shaft speed; the fourth step is to calculate the speed difference between the engine flywheel and the clutch, speed difference = engine speed - driven plate speed.

[0058] It should be further explained that the vehicle condition information also includes the clutch pressing position and the clutch real-time position;

[0059] The steps of obtaining the clutch pressing position and the clutch real-time position include:

[0060] The clutch wear position sensor is used to read the real-time position of the clutch. The minimum value of the clutch wear position sensor is the clutch pressing position, and this position is recorded as the initial point position.

[0061] In some embodiments, Figure 3 As shown, the step of determining the clutch active protection function state machine mode according to the acquired vehicle condition information includes:

[0062] When the transmission gear is in the set gear range and the vehicle speed is less than the calibrated limit, the clutch active protection function state machine mode enters the active protection function preparatory stage; when the transmission gear is in 2-7 gears (calibrable, the specific gear can be calibrated, currently the clutch ablation problem mostly occurs in low gears 1-7, and this function retains 1st gear for normal driving) and the vehicle speed is less than the calibrated limit, the clutch enters the active protection function preparatory stage.

[0063] When the clutch pressure plate moves from the release stage to the tightening stage and the clutch tightening position reaches the contact point (the pressure plate begins to contact the friction plate), the clutch active protection function state machine mode active protection function enters the speed limit mode;

[0064] When the clutch pressing position reaches the initial point, it enters the slow torque mode;

[0065] After entering the slow torque mode, when the clutch slow torque reaches the set percentage of the driver's pedal torque requirement or the slow torque time exceeds the calibrated threshold, the clutch active protection function mode is exited and the normal driving stage is switched. That is, when the clutch slow torque reaches about 80%-90% of the driver's pedal torque requirement, or the slow torque time exceeds the calibrated threshold, the clutch active protection function mode is exited and the normal driving stage is switched.

[0066] If any gear position or vehicle speed exceeds the corresponding calibrated threshold during the preparation stage of the active protection function, the speed limit mode or the slow torque mode, the clutch active protection function will be directly exited.

[0067] In some embodiments, when the clutch active protection function mode is entered, the step of the chassis multi-function controller sending a message to the engine controller through the CAN line to perform engine output speed / torque limit control includes:

[0068] When the clutch active protection function enters the speed limit mode, the chassis multi-function controller sends a TSC1 message to the engine controller via the CAN line to limit the engine speed and make a ramp control output to limit the actual engine speed within the set threshold range.

[0069] When the active protection function enters the speed limit mode, the chassis multi-function controller sends a TSC1 message (general 1939 protocol, used for engine external torque speed control) to the engine ECU (engine controller) via the CAN line. The message content limits the speed and outputs a ramp control to limit the actual engine speed to 1000rpm-1600rpm. (This invention is based on a heavy-duty commercial diesel engine, and the torque point is usually around 1000-1600rpm. This output can ensure that the engine output torque will not be limited to prevent the power from being significantly weakened);

[0070] When the clutch active protection function enters the slow torque mode, the chassis multi-function controller sends the TSC1 message to the engine ECU through the CAN line to limit the engine torque and make a ramp control output, gradually amplifying the actual engine torque from the current actual torque to the set percentage of the current torque output by the driver stepping on the accelerator, thereby completing the gradual increase of torque.

[0071] After entering the slow torque mode, the chassis multi-function controller still sends TSC1 message to the engine ECU through the CAN line. The message content is switched from speed limit to torque limit, and a ramp control output is performed to gradually amplify the actual torque of the engine from the current actual torque to 80%-90% of the current torque output by the driver stepping on the accelerator, completing the gradual increase of torque and preventing sudden switching to normal state to cause the whole vehicle to jerk and other phenomena.

[0072] In this embodiment, the clutch pressure active protection function is switched from the exit to the normal driving stage control method. According to the state machine mode output result, after the clutch protection function is switched to the normal state, the chassis multi-function controller stops sending TSC1 messages to the engine ECU. The vehicle drive returns to the normal state.

[0073] Although the present invention has been described in detail by referring to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily think of changes or substitutions within the technical scope disclosed by the present invention, and these shall be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A control method for the active protection function of a clutch of a manual transmission vehicle, characterized in that: The steps include: Obtain vehicle condition information for entering active protection functions; Determine the clutch active protection function state machine mode based on the acquired vehicle condition information; When the clutch active protection function mode is entered, the chassis multi-function controller sends a message to the engine controller via the CAN line to perform engine output speed / torque limit control; When the clutch active protection function switches to normal state, the chassis multi-function controller stops sending messages to the engine controller, the engine enters normal driving mode, and outputs the clutch friction plate surface temperature at the same time; The vehicle condition information includes engine speed, transmission gear, and the speed difference between the clutch driven plate speed and the engine speed; The steps of obtaining the speed difference between the clutch driven plate speed and the engine speed include: Obtain the engine speed and the transmission output shaft speed; obtain the current transmission gear position in real time through the transmission gear position sensor; obtain the current transmission speed ratio of the transmission according to the current transmission gear position; multiply the current transmission speed ratio of the transmission with the transmission output shaft speed to obtain the clutch driven disc speed; calculate the difference between the clutch driven disc speed and the engine speed as the speed difference; The steps to obtain the engine speed and the transmission output shaft speed include: Read the current vehicle speed, engine speed, and gearbox output shaft speed from the vehicle CAN line; The vehicle condition information also includes a clutch pressing position and a clutch real-time position; the steps of obtaining the clutch pressing position and the clutch real-time position include: The clutch wear position sensor is used to read the real-time position of the clutch in real time. The minimum value of the clutch wear position sensor is the clutch pressing position, and this position is recorded as the initial point position. The step of determining the clutch active protection function state machine mode according to the acquired vehicle condition information includes: When the transmission gear is within the set gear range and the vehicle speed is less than the calibrated limit, the clutch active protection function state machine mode enters the active protection function preparatory stage; when the clutch pressure plate movement state changes from release to tightening stage and the clutch pressing position reaches the contact point, the clutch active protection function state machine mode active protection function enters the speed limit mode; when the clutch pressing position reaches the initial point, it enters the slow torque mode; after entering the slow torque mode, when the clutch slow torque reaches the set percentage of the driver's pedal demand torque or the slow torque time exceeds the calibrated threshold, the clutch active protection function mode is exited and switched to the normal driving stage.

2. The control method for the active clutch protection function of a manual transmission vehicle according to claim 1, characterized in that: The method further includes: If any gear position or vehicle speed exceeds the corresponding calibrated threshold during the preparation stage of the active protection function, the speed limit mode or the slow torque mode, the clutch active protection function will be directly exited.

3. The control method for the active clutch protection function of a manual transmission vehicle according to claim 2, characterized in that: When the clutch active protection function mode is entered, the chassis multi-function controller sends a message to the engine controller through the CAN line to perform engine output speed / torque limit control. The step of the chassis multi-function controller sending a message to the engine controller through the CAN line to perform engine output speed limit control includes: When the clutch active protection function enters the speed limit mode, the chassis multi-function controller sends a TSC1 message to the engine controller via the CAN line to limit the engine speed and make a ramp control output to limit the actual engine speed within the set threshold range.

4. The control method for the active clutch protection function of a manual transmission vehicle according to claim 3 is characterized in that: When the clutch active protection function mode is entered, the chassis multi-function controller sends a message to the engine controller through the CAN line to perform engine output speed / torque limit control. The chassis multi-function controller sends a message to the engine controller through the CAN line to perform engine torque limit control. The step includes: When the clutch active protection function enters the slow torque mode, the chassis multi-function controller sends the TSC1 message to the engine ECU through the CAN line to limit the engine torque and make a ramp control output, gradually amplifying the actual engine torque from the current actual torque to the set percentage of the current torque output by the driver stepping on the accelerator, thereby completing the gradual increase of torque.

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