Research Of Tractor Automatic Mechnical Transmission Shift Rule

With the development of society as well as constant progress of science andtechnology, people have put forward higher requirements on the tractor’s performance.Most of the tractors in China still install the manual mechanical transmissions, whichoften have some faults such as shifting difficult and frequently, making the pilot tiredeasily, and so on. In order to remedy the defects, a high-tech product automaticmechanical transmission is designed on the base of referencing to foreign advancedtechnologies and improving them continuously, which is also known as the AMT, andit is suitable for the national conditions in our country. Tractor AMT has importantsignificance for improving the performance of the tractor and internationalcompetitiveness.Based on researching various factors which influenced the tractor AMT shift rules,and combining with the types as well as characteristics of vehicle automatictransmission shift rule, the types of optimal control parameters of tractor AMT shiftrules are determined. The tractor units’ driving dynamics is researched and dieselengine mathematics model is established by using its test data. On this basis,mathematical model of the tractor AMT dynamic and economic shift rules are derived,and then three-parameter dynamic and economic shift rules are formulated by usingthe graphic method and analytical method. The defaults of shift rules solved bytraditional theories are analyzed and showed, then fuzzy control method is used toimprove the shift rules to control the tractor AMT downshifting process, and finallyshift rules of tractor AMT can be acquired through combining up shift rules solved bytraditional theories and downshift rules obtained by fuzzy control. Simulation modelsof the tractor AMT shift rules are established by using Matlab/Simulink software, andsimulation analysis for the three-parameter shift rules of tractor AMT obtainedrespectively by the advanced and the improved method is did. On the basis of abovework, the tractor power and economic performance affected by the shift rules obtained through two methods are compare studied, which verified the superiority of shift rulesafter the improvement and achieved the desired result.