Design And Research Of Power Shift Transmission Electronic Control System For Tractor

Nowadays manual transmissions are widely used on tractors, which have problems of low production efficiency, high labor intensity of drivers, power interruption in the process of shifting and so on. Power shift transmission can make up these weaknesses in the traditional manual mechanical, besides it can also achieve continuous output power, improve the tractor’s power performance and fuel economy, and decrease the driver’s labor intensity. In order to adapt to the transmission development of tractor in our country, the research about electronic control system of power shift transmission is importantly theoretical and practicably valuable.In this paper, the YTO-1804 is the main study object. Based on introducing the structure and working principle of power shift transmission, the whole system is separated to two main parts, the design of controlling software and the design of controlling hardware. It makes a development plan for transmission control unit(short for TCU) according to the control requirements and the feature of power shift transmission. On the basis of function design of electronic control system, the paper realizes the hardware design for each function module, including input signal collection module, output signal drive module communication module and minimal system etc. What’s more, the thesis also accomplishes the design of the antiinterference capability of the hardware. The software is the role content of electronic control system. Based on the characteristic of μC/OS-II, the real time embedded operation system μC/OS-II is applied on the microprocessor MC9S12XDP512. With the translation of μC/OS-II kernel and design of multi-application tasks, the system meets the requirement for power shift transmission control and improves the performance of real time and reliability. Engine simulation model, transmission simulation model, tractor dynamics simulation model and hydraulic simulation model are founded. Based on dSPACE and Matlab, the semi-physical simulation platform for the tractor power shift transmission controller is built. The simulation test is finished, according to making the controller working in a virtual operation environment. The results show that the electronic control system of the tractor power shift transmission can realize the expected functions.