A shift control system and method for a hybrid electric vehicle

Abstract

The invention provides a gear-shifting control system and method of a hybrid electric vehicle, and belongs to the technical field of vehicles. The gear-shifting control system and method solve the problem that in the gear shifting process of an existing hybrid electric vehicle, running of the vehicle is unstable. The gear-shifting control system of the hybrid electric vehicle comprises a VCU, a TCU, an IPU and a gear shifting sensor, and also comprises a first sensor for collecting input-shaft rotating speed signals, wherein the TCU transmits a flag bit signal to the VCU according to a gear shifting signal, the VCU transmits a torque lowering request to the IPU according to the flag bit signal, and when the torque of a motor is 0 N m, the TCU transmits a gear shifting-down signal; an engine and the motor are connected with a transmission, the motor is connected with an input shaft of the transmission and only can act on the input shaft alone, the TCU transmits a synchronization instruction according to the rotating speed of the input shaft, the synchronization instruction is used for synchronizing the motor and the input shaft and maintaining the 0-N m torque, and when the motor and the input shaft are synchronized, the TCU transmits a motor shifting-up signal to the IPU. According to the gear-shifting control system of the hybrid electric vehicle, the running of the vehicle can be more stable in the gear shifting process, and gear shifting efficiency is higher.

Description

technical field [0001] The invention belongs to the technical field of automobiles, and relates to a hybrid electric vehicle, in particular to a shift control system and method for a hybrid electric vehicle. Background technique [0002] At present, with the increasingly stringent environmental protection measures around the world, hybrid vehicles are increasingly favored by the market due to their energy-saving and low-emission characteristics. Automobile automatic transmissions are mainly divided into AT transmission (AT), continuously variable automatic transmission (CVT), electromechanical automatic transmission (AMT) and dual clutch transmission (DCT). Among them, the dual-clutch transmission has the advantages of fast shifting, fuel economy, high transmission efficiency, and no power interruption for shifting. It is also more and more widely used in hybrid vehicles. [0003] In a DCT hybrid vehicle driven by a motor and an engine, the engine and the motor act on the t...

AI Technical Summary

Problems solved by technology

However, in the actual driving process of the car, the actual speed of the car is not only related to the speed of the transmission. For example, when going uphill or downhill, the actual speed of the car is less than or greater than the power output by the transmission under the action of gravity. Moreover, there are many transmission components between the tire and the transmission, and there will be a certain deviation between these transmission components, resulting in a reduction in transmission accuracy, that is, there will be a discrepancy between the transmission speed deduced from the actual vehicle speed and the real transmission speed. There is a certain error. Therefore, according to this method, the synchronization between the motor and the transmission is poor when the gear is engaged, and there will be a certain impact when the gear is engaged, which affects both the driving experience and the service life of the transmission.

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