Research Of Tractor Semi-active Seat Suspension System Based On Magneto-rheological Damper

As one of the typical traditional agricultural countries, all of the performance of the agricultural equipment must be received great attentions by our country in recent years, such as the tractor, the modified tractor and other properties. Taking into account the special circumstances of the tractor, such as the poorly seat suspension, harsh driving environment, field operations in low speed, road roughness and changing road conditions, this thesis focuses on try to change the tractor seat performance. This way can effectively dissipate road vibration excitation caused by the driver of the vehicle and improve ride comfort that the new smart materials- magneto-rheological fluid be used in the tractor seat suspension. In recent years, magneto-rheological fluid have been highly valued by its so many advantages, such as fast response, low cost, long life, large tuning range, and so on.This thesis focuses on the research ideas that the semi-active seat suspension was built based on the passive seat suspension to improve ride comfort, because the improved space of passive seat suspension too small to effectively damping the lowfrequency vibrations. First, The Bingham model and the modified Bouc-Wen model of the magneto-rheological damper have been constructed combining with the practical needs of this thesis. Both of the magneto-rheological dampers have been characteristic analysed with in the Simulink toolbox. Second, the right road surface input model and the tractor five DOF passive and its semi-active seat suspension dynamic models based on the measured parameters have been established, and vibration characterristic curves of amplitude-frequency have been simulated with the Matlab/Simulink software. Again, With the Matlab/Simulink software, the PID controllor and the fuzzy controllor are established, and the time-domain and frequency-domain characterristics curves are simulatied with the passive and semi-active seat suspension dynamic models in different road excitation and different driving speeds. The results of these simulation indicate that the tractor semi-active seat suspension technology-based the MRF can restrain the vertical vibration in the low zone while enhance the dynamic comfort, and the semi-active suspension system has been proved better than the passive seat system in enhancing the comfort and restraining the vibtation.