A seamless downshift control method for a hybrid system

Abstract

The present invention discloses a seamless downshift control method for a hybrid system, which includes step-by-step steps according to the working process of the clutch, and steps of controlling the front-end motor and engine torque and then adjusting the engine speed to match its target speed. The invention solves or weakens the power interruption during the shifting process, and weakens the feeling of the driver and passengers for the power interruption; adjusts the rotational speed of the engine through torque control, and solves the impact feeling at the beginning or end of the shifting; during the shifting process, the rear end Part or all of the energy used by the motor is provided by the front-end motor, which reduces or eliminates the discharge demand of the battery under this working condition, reduces the dependence on the battery, and reduces the efficiency loss caused by the battery; adjust the torque of the engine through torque control Speed, so that when the clutch is locked, the speed difference between the engine speed and the input shaft speed becomes smaller, and the service life of the clutch can be greatly improved, or a clutch with lower cost can be used.

Description

technical field [0001] The present invention relates to the technical field of automobiles, in particular to a method for controlling torque and vehicle speed during a downshift in a hybrid system. Background technique [0002] At present, among new energy vehicles in my country, hybrid vehicles are developing most rapidly. A hybrid vehicle is a vehicle that uses multiple sources of energy, usually a conventional engine using liquid fuel and an electric motor using electrical energy to drive the vehicle simultaneously or separately. [0003] In the hybrid powertrain of new energy vehicles, multiple motors may appear. The front-end motor that is directly connected to the engine at the front end of the clutch and shares the speed is called the front-end motor, and the common ones are commonly called P0 and P1 motors. The motor at the rear end of the clutch and has a solid connection with the transmission / reducer system is called the rear end motor, and the common ones are ca...

AI Technical Summary

Problems solved by technology

Due to the excessive adjustment of the engine torque (especially in the recovery stage of the clutch transmission torque), the common problems during the shifting process are: slow power response, long shifting time; power interruption during the shifting process, and Vehicle acceleration shock occurs, etc.

Moreover, during the shifting process, the engine speed is controlled through a closed-loop torque limit, which cannot reasonably respond to sudden changes in the driver's driving intentions, and the safety needs to be improved.

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