Seamless downshift control method of hybrid power system

Abstract

The invention discloses a seamless downshift control method of a hybrid power system. The seamless downshift control method comprises the following steps: staging according to the working process of aclutch, and controlling the torque of a front-end motor and an engine to adjust the rotating speed of the engine so as to match the target rotating speed of the engine. Power interruption in the gearshifting process is avoided or weakened, and the feeling of a driver and passengers for power interruption is weakened; the rotating speed of the engine is adjusted through torque control, and the impact feeling at the beginning or the end of gear shifting is avoided; in the gear shifting process, part or all of energy used by a rear-end motor is provided by power generation of the front-end motor, the discharge requirement of a battery under the working condition is reduced or eliminated, the dependence on the battery is reduced, and the efficiency loss caused by the battery is also reduced;and the rotating speed of the engine is adjusted through torque control, so that when the clutch is locked, the speed difference between the rotating speed of the engine and the rotating speed of aninput shaft is reduced, the service life of the clutch can be greatly prolonged, or the clutch with lower cost can be adopted.

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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