| At present, China’s agriculture is moving towards large-scale, intensive andmechanized direction. As the major agricultural production machinery, tractor iswidely used in all aspects of agricultural production. Nowadays manual transmissionsare widely used on tractors, which have problems of low production efficiency andhigh labor intensity of drivers. With the development of the electronic controltechnology and its application on the tractor, Automated mechanical transmission,short for AMT, can achieve the shifting operation automatically, improve the workingefficiency and automatic operation level. The design of the electronic control system isthe research emphasis and difficulty of the tractor AMT, doing research on theelectronic control system of the tractor AMT has the important practical significance toimprove the technological content of domestic tractors and the competitiveness in theinternational market.In this paper, the electronic control system of the tractor AMT was taken as theresearch object, the design of the electronic control system was divided into the designof the controller and the design of the control strategy. Based on the analysis of thecontrol system of AMT, the type of the controller chip and the model of the actuatorwas selected, and the overall scheme of the electronic control system of AMT wasdetermined. TMS320F28335DSP chip was taken as the core, the minimum system ofthe AMT controller was designed as well as the input circuits and output circuits, themajor circuits of the control system was simulated based on Multisim10.0software,the results showed that the designed circuits can realize the expected functions. Thefuzzy control method was used to design the control strategy of the engine rotationalspeed and the clutch engaging speed in the starting process of the tractor. The dynamicthree-parameter shift schedule was formulated by using the tractor speed, the throttleopening degree and the slip rate, and the control strategy of the shift process wasdesigned. By using the matlab software, the whole simulation model of the tractor AMT system was built, the designed electronic control system of the tractor AMT wassimulated and analyzed, the results showed that the electronic control system can makethe tractor start and shift smoothly. |
