Research On Electronic Control System Of Automated Mechanical Transmission

Automated mechanical transmission(AMT) is an automatic transmission which adds a set of start and shift automatic control mechanism on the basis of the traditional gear transmission. AMT automates the traditional manual transmission by the way of electronic transformation. AM T has the advantages of high transmission efficiency, simple structure, low cost, low fuel consumption, low renovation cost, good production inheritance and so on. It is an important branch of the family of the automatic transmission. It is widely used on the lower-end automatic passenger cars and has broad prospects for development. Currently, the important shortcomings which plagued the development of AMT are the low shift quality, poor shift smoothness and poor shift comfort. So improving the shift quali ty of AMT has been the engineers' goal. The shift quality of AMT is directly impacted by its electronic control system, launching the research of the AMT's electronic control system is good for improving the shift quality of AMT vehicles, promoting the dev elopment of AMT technology and expanding the scope of application of AMT.To improve the shift quality of AMT,this paper launches the research from following several aspects under the support of the business cooperation project. Firstly, this paper analyzes the classification and composition of the AMT automatic transmission system and the composition and working principle of the hydraulic AMT which is the focus of the study are described in detail. All of these lay the foundation for the study of AMT's electronic control system. Secondly, the shift control strategy of AMT has been studied; power and economy shift schedules of two parameters have been developed. Then, this paper proposes a shift control strategy based on engine torque and speed and the simulation model of AMT vehicles are established in MATLAB. The simulation verification test of the shift control strategy carried on under the principle of the level of shift quality as an evaluation criterion. The simulation results show that the shift control strategy has good control effect and good shift quality. Thirdly, this paper designs the transmission control unit which is the core component of the electronic control system. They include the selection of microprocessor, schematic design of each functional module and the design of printed circuit board. In addition, the hardware of the transmission control unit is completed. Finally, this paper carries out a depth study on the software system of the transmission control unit. The work about embedded operating system migration and the underlying drivers' code hand-written is completed. Then, the relevant tests of the entire hardware and software system are carried out. The test results show that the transmission control unit which designed in this paper meets the control requirements of the electronic control system of AMT. It can be used as the development prototype of the AMT's control system and it also can be used in the vehicle test of the control strategy.