A control method for self-learning of a single-motor hybrid transmission mode switching clutch

Abstract

The application discloses a control method for self-learning of a single-motor hybrid transmission mode switching clutch, and the method comprises the following steps: step one, detecting the engine starting time and the speed fluctuation during the current mode conversion process; step two, judging according to the target time and the deviation value between the current speed and the target; and step three, correcting and learning the gear shifting process through the deviation value, taking the time difference value as an input variable to perform MAP table lookup, finding out the current value calibrated according to experience, and applying the current value to the control process of the next gear shifting. The self-learning control of the optimized mode clutch is used, so that the mode conversion also achieves good driving feeling, one motor is reduced, and the vehicle cost is greatly saved.

Description

Technical Field

[0001] This invention relates to a control method for using a single motor to tow an engine via a mode clutch. Background Technology

[0002] Developing new energy vehicles is of great significance in addressing environmental pollution and global climate change, as it greatly contributes to reducing carbon emissions, lowering operating costs, enhancing industrial competitiveness, and promoting economic development. Current models generally use a dual-motor structure, where the engine is started by a starter motor, and the motor's speed is then synchronized with the engine's, resulting in higher overall vehicle costs. Summary of the Invention

[0003] The purpose of this invention is to provide a control method for self-learning the mode switching clutch of a single-motor hybrid transmission. By self-learning the mode switching clutch of the single-motor hybrid transmission, the process of starting the engine is made smoother and faster.

[0004] The objective of this invention is achieved through the following technical solution: A control method for self-learning of the mode switching clutch of a single-motor hybrid transmission includes the following steps: Step 1: Detect the engine start time and speed fluctuation during the current mode transition. If the engine start time is not within the target time plus or minus 0.2s (a certain value), or the speed fluctuation is outside the target calculated speed plus or minus 100rpm (a certain value), proceed to Step 2. Step 2: Make a judgment based on the target time, the current rotation speed, and the deviation between the time and the target: Step 2: If the target start time during the oil filling stage is 0, then the engine should not be started at this time. If the target start time during the oil filling stage is not 0 (has a value), then the clutch oil filling pressure needs to be reduced. Step 22: Determine if there is rotational speed during the oil filling stage. If yes, reduce the oil filling pressure of the oil filling stage. If no, proceed to Step 23. Steps 2 and 3: Determine if the engine cannot be started at the specified RPM. If so, increase the holding oil pressure at the specified RPM. If not, proceed to step 2 and 4. Step 24: Determine if the engine speed increases too quickly during the pull-up process. If so, increase the slope of the downward adjustment segment. If not, the gear shifting process is reasonable and the engine starts smoothly. Step 25: During the speed and torque transmission start-up phase, proceed to Step 3 based on the difference between the actual measured time of the speed value and the optimal target time. Step 3: Correct the shifting process using the deviation value obtained in Step 2 and 6. Use the time difference as an input variable to perform a MAP lookup to find the current value calibrated based on experience. Apply the current value to the control process of the next shift (reflected as oil pressure).

[0005] Compared with the prior art, the present invention has the following advantages: This invention achieves a better driving experience during mode switching by using self-learning control of the optimized mode clutch, and reduces one of the motors, thus greatly saving the overall vehicle cost. Attached Figure Description

[0006] Figure 1 A schematic diagram of the P2 architecture layout; Figure 2 Here is a flowchart of the self-learning process for the mode clutch; Figure 3 This is a control chart for the actual gear shifting process. Detailed Implementation

[0007] The technical solution of the present invention will be further described below with reference to the accompanying drawings, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention that do not depart from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention.

[0008] This invention provides a control method for self-learning of the mode switching clutch in a single-motor hybrid transmission, such as... Figure 2 As shown, the method is as follows: Step 1: Detect the engine start time and speed fluctuation during the current mode transition. If the engine start time is not within the target time plus or minus 0.2s (a certain value), or the speed fluctuation is outside the target calculated speed plus or minus 100rpm (a certain value), proceed to Step 2. Step 2: Make a judgment based on the target time, the current rotation speed, and the deviation between the time and the target: Step 2: If the target start time during the oil filling stage is 0, then the engine should not be started at this time. If the target start time during the oil filling stage is not 0 (has a value), then the clutch oil filling pressure needs to be reduced. Step 22: Determine if there is rotational speed during the oil filling stage. If yes, reduce the oil filling pressure of the oil filling stage. If no, proceed to Step 23. Steps 2 and 3: Determine if the engine cannot be started at the specified RPM. If so, increase the holding oil pressure at the specified RPM. If not, proceed to step 2 and 4. Step 24: Determine if the engine speed increases too quickly during the pull-up process. If so, increase the slope of the downward adjustment segment. If not, the gear shifting process is reasonable and the engine starts smoothly. Step 25: During the speed and torque transmission start-up phase, proceed to Step 3 based on the difference between the actual measured time of the speed value and the optimal target time. Step 3: Correct the shifting process using the deviation value obtained in Step 2 and 6. Use the time difference as an input variable to perform a MAP lookup to find the current value calibrated based on experience. Apply the current value to the control process of the next shift (reflected as oil pressure).

[0009] 1. Structural Introduction: like Figure 1 As shown, the mode switching clutch K0 in the P2 hybrid architecture is located between the engine and the transmission. When switching from pure electric mode to hybrid mode, the K0 clutch engages, and the electric motor drives the engine. The engagement process of the K0 clutch directly affects the quality of mode switching.

[0010] 2. Gear shift learning control method: 2.1 Control objectives: the timing of engine start-up and the time it takes for engine speed to reach a certain value, i.e., the engine speed rises smoothly, the mode switching process is smooth, and the driving experience is good.

[0011] 2.2 Evaluation Criteria and Control Methods: ① When the clutch control pressure is too high, premature engagement will cause the clutch to engage and generate shock and speed overshoot. At this time, it is necessary to reduce the clutch control pressure so that the clutch oil chamber is just filled, so that there is neither insufficient filling nor overfilling that will cause shock. Do not start the engine during the clutch oil chamber filling stage. ② When the clutch pressure is too low, the engine may not be able to start for a long time or the shifting time may be too long, causing a shock due to forced end of the shifting, which affects the driving experience. In this case, it is necessary to increase the clutch pressure during the slip-and-lift phase of the shifting process, determine the required control current based on the current lifting torque, and then convert it into control pressure, while ensuring that the engine speed rises steadily.

[0012] In this invention, the control current is gradually reduced according to a preset step size, and a suitable current value can generally be found after three steps.

[0013] Actual shift process control such as Figure 3 As shown, by Figure 3 As can be seen, the engine speed rises smoothly, the mode switching process is smooth, and the driving experience is good.

Claims

1. A control method for self-learning of the mode-switching clutch in a single-motor hybrid transmission, characterized in that... The method includes the following steps: Step 1: Detect the engine start time and speed fluctuation during the current mode transition. If the engine start time is not within 0.2 seconds of the target time, or the speed fluctuation is more than 100 rpm above or below the target calculated speed, proceed to Step 2. Step 2: Make a judgment based on the target time, the current rotation speed, and the deviation between the time and the target: Step 2: If the target start time during the oil filling stage is 0, then the engine should not be started at this time. If the target start time during the oil filling stage is not 0, then the clutch oil filling pressure needs to be reduced. Step 22: Determine if there is rotational speed during the oil filling stage. If yes, reduce the oil filling pressure of the oil filling stage. If no, proceed to Step 23. Steps 2 and 3: Determine if the engine cannot be started at the specified RPM. If so, increase the holding oil pressure at the specified RPM. If not, proceed to step 2 and 4. Step 24: Determine if the engine speed increases too quickly during the pull-up process. If so, increase the slope of the downward adjustment segment. If not, the gear shifting process is reasonable and the engine starts smoothly. Step 25: During the speed and torque transmission start-up phase, proceed to Step 3 based on the difference between the actual measured time of the speed value and the optimal target time. Step 3: Correct the shifting process using the deviation value obtained in Step 2 and 6. Use the time difference as an input variable to perform a MAP lookup table to find the current value calibrated based on experience. Apply the current value to the control process of the next shift.

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