Hybrid truck clutch control method and vehicle

Abstract

The present application relates to a kind of hybrid truck clutch control method and vehicle, control strategy is based on the parallel P2 configuration of hybrid power system;Including the following steps: by HCU integrated clutch control module, the clutch combination or separation when starting engine, drive mode jump flag bit determination, parking charging, engine speed regulation is completed in the condition under the flag bit determination in gear shifting process, to determine the action timing and displacement of clutch execution combination or separation.The present application makes engine smooth start, engine intervention and exit time input shaft speed transition smooth, gear shifting smoothness is good, gear shifting response speed is fast, vehicle speed fluctuation is small, and can satisfy the clutch control strategy when in gear sliding or braking and neutral sliding.

Description

Technical Field

[0001] This invention relates to the field of automotive control technology, and more particularly to a hybrid truck clutch control method and vehicle. Background Technology

[0002] Heavy-duty trucks consume vast amounts of petroleum and are among the largest sources of CO2 emissions in the transportation sectors of major economies worldwide. Adopting hybrid technology is a crucial approach to reducing fuel consumption and harmful emissions in heavy-duty trucks. A core aspect of hybrid system development is clutch control, which directly affects engine engagement and disengagement, significantly impacting the vehicle's fuel economy and driving comfort. Summary of the Invention

[0003] This invention proposes a clutch control method and vehicle for a hybrid truck, which enables smooth engine start-up, smooth transition of input shaft speed during engine engagement and disengagement, good shift smoothness, fast shift response speed, small vehicle speed fluctuation, and can meet the clutch control requirements during coasting in gear, braking, and coasting in neutral.

[0004] To address the problems mentioned above in the background section, the present invention is achieved through the following technical solution: A hybrid truck clutch control method, the control method being based on a parallel P2 hybrid system, includes the following steps: by integrating a clutch control module in the HCU, determining the clutch engagement or disengagement during engine start-up, the drive mode jump flag, the parking charging, and the flag indicating engine speed adjustment completion during gear shifting, to determine the timing and displacement of the clutch engagement or disengagement action.

[0005] Preferably, the method for determining the timing and displacement of clutch engagement or disengagement by judging the flag position when the clutch is engaged or disengaged during engine start-up through the HCU integrated clutch control module is as follows: the engine start-up method is determined according to the vehicle drive mode, specifically by controlling the clutch engagement through the HCU, driving the engine to start through the hybrid electric motor, and controlling the clutch disengagement after the engine starts at the starting speed; the engine starts with its own starter motor, at which time the clutch is in the disengaged state.

[0006] Preferably, the method for determining the timing and displacement of clutch engagement or disengagement by judging the drive mode jump flag through the HCU integrated clutch control module is as follows: First, based on the driver's torque demand and the distribution of the engine and motor's high-efficiency zones, the motor torque limit and optimal engine torque value for different engine speeds and power battery SOC ranges are obtained from a table. Then, the optimal engine efficiency linear control method is used to control the motor and engine torque. Arbitration and allocation are performed to ensure that the engine and motor always operate in the high-efficiency range by controlling the clutch.

[0007] Preferably, the method for determining the timing and displacement of clutch engagement or disengagement by judging the clutch engagement or disengagement completion status under parking charging conditions through the HCU integrated clutch control module is as follows: According to the driver's needs, when the parking power generation switch is pressed, the following conditions must be met simultaneously: vehicle speed is 0, current gear is N, parking brake is effective, engine is idling, vehicle brake air pressure is normal, high voltage is working normally, and SOC is lower than the upper limit of rechargeable value. The HCU integrated clutch control module controls the parking power generation to work, controls the engine and motor speeds to the set speeds, engages the clutch, controls the motor to output negative torque to charge the power battery, and controls the clutch to disengage after parking charging is completed.

[0008] Preferably, the method for determining the timing and displacement of clutch engagement or disengagement by judging the flag position of the engine speed adjustment completion condition during the gear shifting process through the HCU integrated clutch control module is as follows: During the gear shifting process, the HCU calculates and controls the engine and drive motor to complete the speed adjustment synchronization of the transmission input shaft and output shaft according to the target gear. When the speed adjustment synchronization flag position is 1, the HCU integrated clutch control module controls the clutch to engage, preparing for the engine torque recovery after the gear shift is completed.

[0009] Preferably, the system also includes controlling the clutch's action requirements according to the driving conditions and drive mode through an integrated clutch control module via the HCU, and finally outputting clutch control commands, clutch position commands, clutch no-torque engagement flags, and clutch torque engagement flags; the clutch control commands are: clutch partially engaged at a certain torque; clutch fully engaged; clutch disengaged. 1) Determine if the vehicle is in the process of shifting gears. If it is in the process of shifting gears and the transmission input shaft speed is less than the clutch disengagement speed, the HCU integrated clutch control module sends a clutch disengagement command; if it is in the process of shifting gears but the transmission input shaft speed is not less than the clutch disengagement speed, the clutch command sent by the HCU remains unchanged from the previous state; otherwise, proceed to 2). 2) Determine if there is a request for normal engine start. If there is such a request, the HCU integrated clutch control module sends a clutch disengagement command; otherwise, proceed to 3). 3) Determine if there is a request for starting the engine in motor speed mode. If there is such a request and the engine start has not failed, the HCU integrated clutch control module sends a clutch engagement command; if there is such a request but the engine start has failed, the HCU integrated clutch control module sends a clutch disengagement command; otherwise, proceed to 4). 4) Determine if there is a request for starting the engine in motor torque mode. If there is such a request and the engine start has not failed, the HCU integrated clutch control module sends a clutch position command to control the clutch to be partially engaged; if there is such a request and the engine start has failed, the HCU integrated clutch control module sends a clutch disengagement command; otherwise, proceed to 5). 5) Determine if there is a clutch engagement request command and the transmission input shaft speed is greater than the clutch disengagement speed, the HCU... The integrated clutch control module sends a clutch no-torque engagement flag of 1, and simultaneously checks whether engine speed adjustment is complete. If speed adjustment is complete, the HCU integrated clutch control module sends a clutch engagement command; if speed adjustment is not complete, the clutch command sent by the HCU integrated clutch control module remains unchanged from the previous moment; otherwise, proceed to step 6). 6) Check if there is a clutch engagement requirement command and if the transmission input shaft speed is less than the clutch disengagement speed. The HCU integrated clutch control module sends a clutch torque engagement flag of 1, and sends a clutch position command to control the clutch to be partially engaged. Simultaneously, check whether engine speed adjustment is complete. If speed adjustment is complete, the HCU integrated clutch control module sends a clutch engagement command; if speed adjustment is not complete, the clutch command sent by the HCU integrated clutch control module remains unchanged from the previous moment; otherwise, proceed to step 7). 7) Check if there is a clutch disengagement requirement. If there is, the HCU integrated clutch control module sends a clutch disengagement command; otherwise, the clutch command sent by the HCU integrated clutch control module remains unchanged from the previous moment.

[0010] Preferably, the driving modes include neutral coasting and full vehicle drive mode; based on the AMT splash lubrication requirements during neutral coasting, the clutch engagement is controlled by the HCU integrated clutch control module, and the accelerator pedal position, brake pedal position, current vehicle speed, and shifting process are judged when the shift lever is shifted to neutral to realize clutch engagement control during neutral coasting; and according to the driver's needs, the transition from neutral coasting mode to full vehicle drive mode is realized by collecting the signal of the shift lever executing from N gear to D gear and the brake pedal position.

[0011] Preferably, a vehicle includes the hybrid truck clutch control method as described in any of the above.

[0012] Compared with the prior art, the present invention has the following beneficial technical effects: It enables smooth engine start-up, smooth transition of input shaft speed during engine engagement and disengagement, good shift smoothness, fast shift response, small vehicle speed fluctuation, and can meet the clutch control requirements during coasting in gear, braking, and coasting in neutral. Attached Figure Description

[0013] Figure 1 This is a flowchart of the present invention; Figure 2 This is a flowchart illustrating the clutch engagement requirement determination process of the present invention. Figure 3 This is a flowchart illustrating the clutch disengagement requirement determination of the present invention; Detailed Implementation

[0014] Example 1 like Figure 1 The method describes a hybrid truck clutch control method based on a parallel P2 hybrid system; it includes the following steps: integrating a clutch control module via an HCU to control the clutch during engine start-up. The timing and displacement of clutch engagement or disengagement are determined by judging the clutch engagement or disengagement, the drive mode jump flag, the parking charging, and the flag indicating engine speed adjustment completion during gear shifting.

[0015] The method for determining the timing and displacement of clutch engagement or disengagement during engine start-up by judging the flag position when the clutch is engaged or disengaged during engine start-up using the HCU integrated clutch control module is as follows: the engine start-up method is determined according to the vehicle drive mode. Specifically, the clutch is engaged by controlling the HCU to start the engine, which is driven by the hybrid electric motor. Once the engine starts at the engine speed, the clutch is disengaged. Alternatively, the engine can be started by its own starter motor, at which point the clutch is disengaged.

[0016] The method for determining the timing and displacement of clutch engagement or disengagement by judging the drive mode jump flag using the HCU integrated clutch control module is as follows: First, based on the driver's torque requirements and the distribution of the engine and motor's high-efficiency zones, the motor torque limit and the optimal engine torque value for different engine speeds and power battery SOC ranges are obtained by referring to a table. The optimal engine efficiency line control method is used to arbitrate and distribute the motor and engine torques, and the clutch is controlled to ensure that the engine and motor always operate in the high-efficiency zone.

[0017] The method for determining the timing and displacement of clutch engagement or disengagement during parking charging by judging the clutch engagement or disengagement completion status of the HCU integrated clutch control module is as follows: According to the driver's needs, when the parking power generation switch is pressed, the following conditions must be met simultaneously: vehicle speed is 0, current gear is N, parking brake is effective, engine is idling, vehicle brake air pressure is normal, high voltage is working normally, and SOC is lower than the upper limit of rechargeable value. The HCU integrated clutch control module controls the parking power generation to work, controls the engine and motor speeds to the set speeds, engages the clutch, and controls the motor to output negative torque to charge the power battery. After parking charging is completed, the clutch is controlled to disengage.

[0018] The method for determining the timing and displacement of clutch engagement or disengagement by judging the flag position when the engine speed adjustment is completed during the shifting process through the HCU integrated clutch control module is as follows: During the shifting process, the HCU calculates and controls the engine and drive motor to complete the speed adjustment synchronization of the transmission input shaft and output shaft according to the target gear. When the speed adjustment synchronization flag position is 1, the HCU integrated clutch control module controls the clutch to engage, preparing for the engine torque recovery after the shift is completed.

[0019] The clutch control states are as follows: First, the clutch moves from disengagement to engagement; second, the clutch remains engaged. When the clutch is disengaged and the engine is running, if the vehicle meets any of the following conditions, the target state of clutch control is determined to be engaged, and the clutch engagement request flag will be set to 1. a) Engine idling, parking brake effective, vehicle speed 0, parking charging button pressed; b) The vehicle's drive mode requires engine intervention based on current torque demands, such as transitioning from pure electric to pure engine in hybrid mode, transitioning from pure electric to engine in hybrid mode, or transitioning from coasting or regenerative braking to pure engine in hybrid mode. When the engine needs to disengage from vehicle drive, the clutch will disengage when the drive mode changes accordingly. c) Entering neutral coasting mode. If the vehicle's drive mode is in any of the following modes, the clutch disengagement requirement flag will be set to 1. d) Drive mode is pure electric mode in hybrid mode; e) Engine to electric motor transition in hybrid mode; f) Engine to coasting or regenerative braking transition in hybrid mode. Except for mode c), if the transmission input shaft speed is lower than the clutch disengagement speed and the engine is running, the clutch should also remain engaged if the vehicle's drive mode is in any of the following modes, and the clutch engagement requirement flag will be set to 1. g) Drive mode is in pure engine mode; h) Drive mode is in pure engine mode under hybrid mode, etc.; i) Drive mode is in pure engine mode transitioning to pure electric mode under hybrid mode; j) Drive mode is in electric motor assist mode under hybrid mode; k) Drive mode is in initialization mode under hybrid mode. During vehicle operation, clutch engagement requires engine speed adjustment. When the difference between the engine speed and the transmission input shaft speed is less than the allowable clutch engagement speed difference, clutch engagement is allowed at position 1 of the engine speed adjustment completion flag.

[0020] Example 2 It also includes controlling the clutch action requirements according to the driving conditions and drive mode through the HCU integrated clutch control module, and finally outputting clutch control commands, clutch position commands, clutch no-torque engagement flag and clutch torque engagement flag; the clutch control commands are: clutch partially engaged at a certain torque; clutch fully engaged; clutch disengaged. 1) Determine if the vehicle is in the process of shifting gears. If it is in the process of shifting gears and the transmission input shaft speed is less than the clutch disengagement speed, the HCU integrated clutch control module sends a clutch disengagement command. If it is in the process of shifting gears but the transmission input shaft speed is not less than the clutch disengagement speed, the clutch command sent by the HCU remains unchanged from the previous state. Otherwise, proceed to 2). 2) Determine if there is a normal engine start request. If there is such a request, the HCU integrated clutch control module sends a clutch disengagement command. Otherwise, proceed to 3). 3) Determine if there is a request to start the engine in motor speed mode. If there is such a request and the engine starts successfully, the HCU integrated clutch control module sends a clutch engagement command; if there is such a request but the engine starts fail, the HCU integrated clutch control module sends a clutch disengagement command; otherwise, proceed to 4). 4) Determine if there is a request to start the engine in motor torque mode. If there is such a request and the engine starts successfully, the HCU integrated clutch control module sends a clutch position command to control the clutch to partially engage; if there is such a request and the engine starts fail, the HCU integrated clutch control module sends a clutch disengagement command; otherwise, proceed to 5). 5) Determine if there is a clutch engagement request command and the transmission input shaft speed is greater than the clutch disengagement speed. The HCU integrated clutch control module sets the clutch no-torque engagement flag to 1, and simultaneously determines whether engine speed adjustment is complete. If speed adjustment is complete, the HCU integrated clutch control module sends... Send a clutch engagement command; if speed adjustment is not completed, the clutch command sent by the HCU integrated clutch control module remains unchanged from the previous moment; otherwise, proceed to step 6); 6) Determine if there is a clutch engagement requirement command and the transmission input shaft speed is less than the clutch disengagement speed. The HCU integrated clutch control module sends a clutch torque engagement flag of 1 and a clutch position command to control the clutch to partially engage. At the same time, determine if engine speed adjustment is completed. If speed adjustment is completed, the HCU integrated clutch control module sends a clutch engagement command; if speed adjustment is not completed, the clutch command sent by the HCU integrated clutch control module remains unchanged from the previous moment; otherwise, proceed to step 7); 7) Determine if there is a clutch disengagement requirement. If there is, the HCU integrated clutch control module sends a clutch disengagement command; otherwise, the clutch command sent by the HCU integrated clutch control module remains unchanged from the previous moment.

[0021] The driving modes include neutral coasting and full vehicle drive mode. Based on the AMT splash lubrication requirements during neutral coasting, the clutch engagement is controlled by the HCU integrated clutch control module. The system also judges the accelerator pedal position, brake pedal position, current vehicle speed, and shifting process when the gear shift lever is shifted to neutral to achieve clutch engagement control during neutral coasting. Furthermore, according to the driver's needs, the system switches from neutral coasting mode to full vehicle drive mode by collecting the signal from the gear shift lever shifting from N to D and the brake pedal position.

[0022] Example 3 A vehicle comprising a hybrid truck clutch control method as described in any of the above.

Claims

1. A hybrid truck clutch control method, characterized in that: The control method is based on a parallel P2 configuration hybrid power system; The steps include: using the HCU integrated clutch control module to determine the timing and displacement of clutch engagement or disengagement during engine start-up, the determination of drive mode jump flag, the determination of flags during parking charging, and the determination of flags when engine speed adjustment is completed during gear shifting. It also includes controlling the clutch action requirements according to the driving conditions and drive mode through the HCU integrated clutch control module, and finally outputting clutch control commands, clutch position commands, clutch no-torque engagement flag and clutch torque engagement flag; the clutch control commands are: clutch partially engaged at a certain torque; clutch fully engaged; clutch disengaged. 1) Determine if the vehicle is in the process of shifting gears. If it is in the process of shifting gears and the transmission input shaft speed is less than the clutch disengagement speed, the HCU integrated clutch control module sends a clutch disengagement command; if it is in the process of shifting gears, but the transmission input shaft speed is not less than the clutch disengagement speed, then the HCU... The sent clutch command remains unchanged from the previous state; otherwise, proceed to 2); 2) Determine if there is a normal engine start request. If there is, the HCU integrated clutch control module sends a clutch disengagement command; otherwise, proceed to 3); 3) Determine if there is a request to start the engine in motor speed mode. If there is, and the engine start has not failed, the HCU integrated clutch control module sends a clutch engagement command; if there is, but the engine start has failed, the HCU integrated clutch control module sends a clutch disengagement command; otherwise, proceed to 4); 4) Determine if there is a request to start the engine in motor torque mode. If there is, and the engine start has not failed, the HCU integrated clutch control module sends a clutch position command to control the clutch to be partially engaged; if there is, and the engine start has failed, the HCU integrated clutch control module sends a clutch disengagement command; otherwise, proceed to 5); 5) Determine if there is a clutch engagement request command and the transmission input shaft speed is greater than the clutch disengagement speed, the HCU integrated clutch control module sends a clutch no-torque engagement command. If the clutch engagement flag is set to 1, the system checks whether engine speed adjustment is complete. If speed adjustment is complete, the HCU integrated clutch control module sends a clutch engagement command; if speed adjustment is incomplete, the clutch command sent by the HCU integrated clutch control module remains unchanged from the previous moment; otherwise, proceed to step 6). 6) If there is a clutch engagement requirement command and the transmission input shaft speed is less than the clutch disengagement speed, the HCU integrated clutch control module sends a clutch torque engagement flag set to 1 and sends a clutch position command to control the clutch to partially engage. At the same time, it checks whether engine speed adjustment is complete. If speed adjustment is complete, the HCU integrated clutch control module sends a clutch engagement command; if speed adjustment is incomplete, the clutch command sent by the HCU integrated clutch control module remains unchanged from the previous moment; otherwise, proceed to step 7). 7) If there is a clutch disengagement requirement, the HCU integrated clutch control module sends a clutch disengagement command; otherwise, the clutch command sent by the HCU integrated clutch control module remains unchanged from the previous moment.

2. The hybrid truck clutch control method according to claim 1, characterized in that, The method for determining the timing and displacement of clutch engagement or disengagement during engine start-up by judging the flag position when the clutch is engaged or disengaged during engine start-up using the HCU integrated clutch control module is as follows: the engine start-up method is determined according to the vehicle drive mode. Specifically, the clutch is engaged by controlling the HCU to start the engine, which is driven by the hybrid electric motor. Once the engine starts at the engine speed, the clutch is disengaged. Alternatively, the engine can be started by its own starter motor, at which point the clutch is disengaged.

3. The hybrid truck clutch control method according to claim 1, characterized in that, The method for determining the timing and displacement of clutch engagement or disengagement by judging the drive mode jump flag using the HCU integrated clutch control module is as follows: First, based on the driver's torque requirements and the distribution of the engine and motor's high-efficiency zones, the motor torque limit and the optimal engine torque value for different engine speeds and power battery SOC ranges are obtained by referring to a table. The optimal engine efficiency line control method is used to arbitrate and distribute the motor and engine torques, and the clutch is controlled to ensure that the engine and motor always operate in the high-efficiency zone.

4. The hybrid truck clutch control method according to claim 1, characterized in that, The method for determining the timing and displacement of clutch engagement or disengagement during parking charging by judging the flag position during parking charging is as follows: According to the driver's needs, when the parking power generation switch is pressed, the following conditions must be met simultaneously: vehicle speed is 0, current gear is N, parking brake is effective, engine is idling, vehicle brake air pressure is normal, high voltage is working normally, and SOC is lower than the upper limit of rechargeable value. The HCU integrated clutch control module controls parking power generation, controls the engine and motor speed to the set speed, engages the clutch, controls the motor to output negative torque to charge the power battery, and controls the clutch to disengage after parking charging is completed.

5. The hybrid truck clutch control method according to claim 1, characterized in that, The method for determining the timing and displacement of clutch engagement or disengagement by judging the flag position when the engine speed adjustment is completed during the shifting process through the HCU integrated clutch control module is as follows: During the shifting process, the HCU calculates and controls the engine and drive motor to complete the speed adjustment synchronization of the transmission input shaft and output shaft according to the target gear. When the speed adjustment synchronization flag position is 1, the HCU integrated clutch control module controls the clutch to engage, preparing for the engine torque recovery after the shift is completed.

6. The hybrid truck clutch control method according to claim 5, characterized in that, The driving modes include neutral coasting and full vehicle drive mode. Based on the AMT splash lubrication requirements during neutral coasting, the clutch engagement is controlled by the HCU integrated clutch control module. The accelerator pedal position, brake pedal position, current vehicle speed, and shifting process are judged when the gear shift lever is shifted to neutral to achieve clutch engagement control during neutral coasting. Furthermore, according to the driver's needs, the transition from neutral coasting mode to full vehicle drive mode is achieved by collecting the signal of the gear shift lever shifting from N to D and the brake pedal position.

7. A vehicle, characterized in that, The method includes the hybrid truck clutch control method according to any one of claims 1-6.

Images