Research On The Shift Mechanism And Control System Of Transmission Applying To Hybrid Electrical Bus

The Hybrid Electric Bus (HEB) is a synthesis and highly integrated system which includes more than two power systems, and those power systems can work coordinately. In order to make the power systems work more coordinately and make the energy consumption and emission lower, the transformation in the power train should shift automatically. Compared to other automatic transmission, Automatic Mechanical Transmission (AMT) is more suitable for the current car industry of our county, because of its better production succession,higher efficiency and so on. When the research and development of HEB are becoming a hot spot, doing the research on transformation applying to HEB has more practical significance.It is quite important and difficult to design and optimize the shift mechanism and develop the control system for the transmission mechanism used in HEB, as well as the reliability of them. Moreover, how to get the optimum gear is also important for the transformation applying to HEB. Combining with the requirements of HEB to transformation and choosing a specific model-SG154-90 as the object of study, The shift mechanism and the control system of transmission applying to the HEB are studied in this thesis.The main research contents are as follows:1) Based on the discussion of the development situation of the HEB and the AMT home and abroad, the problems of the AMT's research are indicated and the requirements of the HEB to the shifting are analysed.2) The requirements of three kinds of shift mechanism are analysed concretely, and On that basis, aimed at the need of HEB's gear-shift, two design projects of shift mechanism are stated, which are called motor-driven and parallel shift mechanism and motor-driven and crossed shift mechanism.3) Based on the study of getting the traditional bus's optimum gear and the analysis of Parallel Hybrid Electric Bus (PHEB)'s work-mode, the shift Schedule of PHEB is presented, and the method of solving it is given.4) in order to make sure the mechanism's reliability enough,The tool of reliability analysis-Failure Mode and Effects Analysis (FMEA) is used in the design process of the shift mechanism,and the reliability of the designed shift mechanism is analysed.5) Aimed at the need of PHEB's gear-shift, the structure of the hardware system is designed. On the basis of thePHEB's shift schedule, the solving flow of the optimum gear.is designed. Meanwhile, both of hardware and software have been used to strengthen the reliability of the control system.