Study On The Design For Automated Mechanical Transmission System Of Tractor

The agriculture plays an important role in the national economy in our country. The tractor is particularly important in the agricultural mechanization, with the increasing agricultural infrastructure investment in recent years. Although domestic tractors have been improved greatly from model to vehicle performance in recent years, there is still a gap with the developed countries in the aspects of power train design and control. The traditional domestic tractor mostly adopts manual transmission, but it has some shortcomings such as difficult and complicated operating and it is easy to make driver fatigue. While besides making up for these deficiencies, the automated mechanical transmission (AMT) also offers many advantages in terms of simple structure, low cost, good inheritance etc. Therefore, the study on tractor AMT transmission system becomes the focus of the tractor designing.Based on the elaborating of the structure and working principle of AMT system, the tractor working conditions and the characteristic of engine are analyzed. and the matching calculation and optimization design for the tractor transmission parameters are achieved. Combined with disk spring characteristic and clutch characteristic, the control strategies of clutch in field starting condition and shifting process are designed in the requirement scopes of impact degree and friction work. Shifting process is studied considering the function requirements of the power train. Researching the impacts on drive system from the engine speed when combining the clutch, the engine speed control strategy is formulated. The optimal three-parameter dynamic and economic shifting rules, shifting control strategy are worked out. The simulation models of power train and control strategy of tractor AMT are established by using Matlab/Simulink, then the multi-domain simulation is done in Matlab environment to test the comprehensive control strategy. After using the MATLABâ—‹RDLL module in the CRUISE, embedding the AMT integrated control model, analyzing the joint simulation results, the validity of the design parameters for AMT dynamic system, the feasibility of the control strategy and the tractor good comprehensive performance are all verified.