Hybrid electric vehicle power upshift process control method

Abstract

The invention discloses a hybrid electric vehicle power upshift process control method which comprises the following steps: in an oil charge phase, controlling the oil pressure of an OG clutch and the oil pressure of an OC clutch; in the torque phase, in order to keep the output torque of the transmission constant, the motor torque is controlled based on the output torque to increase the input torque, and the OG clutch and the OC clutch are cooperatively controlled to complete torque exchange; in the speed phase, the motor torque is controlled to be reduced based on the target angular acceleration of the input shaft, and the torque reduction value of the motor is cancelled after the slip frequency of the OC clutch is reduced to 0; and in the locking phase, the oil pressure of the OC clutch is controlled to lock the clutch. According to the method, the input torque is calculated based on the transmission output torque in the four stages of the powered upshift process, the output torque can be controlled to be kept unchanged, the powered upshift process is controlled through the motor auxiliary torque, the gear shifting time is effectively shortened, sliding friction work in the gear shifting process is reduced, gear shifting impact is reduced, and the gear shifting efficiency is improved. And the riding comfort is improved.

Description

technical field [0001] The present invention relates to the technical field of a hybrid vehicle transmission system, in particular to a method for controlling a powered upshift process of a hybrid vehicle. Background technique [0002] In the existing fuel vehicles, the driving power demand is analyzed by the engine control unit, and the shift process control is performed by the transmission control unit. The engine control unit cannot accurately obtain the state information of each stage in the shift process control. When analyzing the driving demand torque, the engine control unit generally does not consider the influence of the reduction of the transmission ratio on the output torque during the power upshift process, nor does it control the output torque to remain unchanged by increasing the engine torque. The torque swapping between the OG clutch and the OC clutch can cause shift shock and reduce ride comfort. [0003] Due to the slow response speed and poor accuracy of...

AI Technical Summary

Problems solved by technology

[0002] In existing fuel vehicles, the driving power demand is analyzed by the engine control unit, and the shift process control is performed by the transmission control unit. The engine control unit cannot accurately obtain the status information of each stage in the shift process control

When the engine control unit analyzes the driving demand torque, it generally does not consider the impact of the reduction of the transmission ratio on the output torque in the process of power upshifting, nor does it control the output torque by increasing the engine torque to keep the output torque constant. Therefore, in the torque When the phase OG clutch and OC clutch perform torque exchange, it will cause shift shock and reduce ride comfort

[0003] Due to the slow response speed and poor accuracy of the transient torque of the engine, on the premise of ensuring a certain shift comfort, the speed phase during the power upshift process uses the engine to reduce the torque to adjust the speed, which will make it difficult to further increase the shift time. Compression is not conducive to reducing energy loss during gear shifting, and greater friction work will shorten the service life of the clutch

[0004] To sum up, the reduction of the transmission ratio during power upshifting will lead to shifting impact and reduce ride comfort; during the power upshifting process, the use of engine down-torque speed regulation during the speed phase will make it difficult to further compress the shifting time. It is not conducive to reducing the energy loss during the shifting process; therefore, it is necessary to propose a set of clear and detailed theoretical formulas and control methods for the motor-assisted control of the power upshift process based on the transmission output torque of the P2 configuration hybrid electric vehicle, in order to Effectively improve shift quality

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