Study On The AMT Shift Strategy For Parallel Hybrid Electric Bus

The study of hybrid electric vehicles laid stress on the energy management strategy and the torque distribution strategy, however the study on the shift schedule and shift-decided strategy is relatively less. Present hybrid electric vehicle most directly use the two- parameter shift schedule of conventional vehicles, because there is great different between hybrid electric vehicles and conventional vehicles in construction, working principle and vehicle control strategy, so it is unreasonable to use the two- parameter shift schedule of conventional vehicles in the shift control of hybrid electric vehicle. This paper focuses on the single-axle parallel hybrid electric bus, select shift control parameters, make reasonable shift schedule and shift-decided strategy, mainly done the following work.1. Discussed the development history and current status of hybrid electric vehicles in the domestic and foreign countries. Overview of the classification of the automatic transmission, compared the advantages and disadvantages of each type of automatic transmission. The problems that is consist in the shift schedule making process were found out, the research tasks are advanced.2. Analyzed the classification and working principle of hybrid electric vehicles, and tested torque characteristics and fuel consumption of the engine used in the hybrid bus, which was researched in this paper.3. According to the construction, working principle and vehicle control strategy, select the vehicle speed, engine throttle and the motor equivalent throttle as shift control parameters. Developing a three-parameters shift schedule for the single-axle parallel hybrid electric bus based on two-parameters shift schedule of conventional vehicles. 4. Studied the intellectual shift-decided strategy, amendment the three parameters shift schedule based on the driver's driving style and vehicle driving conditions, finally a reasonable shift-decided was gotten.5. Modified simulation parameters and built simulation models, based on ADVISOR simulation software. Analyzed the reasonable of the three parameters shift schedule using simulation method.