Research On Semi-active Control Of Multi-dimensional Vibration Reduction Seat Mechanism

Due to the large input vibration excitation of the heavy commercial vehicles and the poor vibration damping performance of the vehicle suspension system,the driver is in a condition of significant low-frequency vibration for a long period of time,which seriously affects the ride comfort of the commercial vehicle and affects the health of the driver cause some damages.It is one of the major topics in the field of vibration reduction of commercial vehicles to carry out research on low frequency vibration damping control of automobile seats.Based on the Tianjin University-RMIT University International Cooperation Project,this dissertation takes a heavy commercial vehicle seat as research object,and aims to study the semi-active control multi-dimension damping problem of car seat in low frequency vibration environment.The main research route is as follows: Combining the new MRE damper with the Stewart parallel mechanism,the purpose of multi-dimension damping is achieved,and the semi-active control of the vibration damping mechanism is studied.The kinematics and dynamics analysis of the Stewart parallel mechanism were carried out in the dissertation,and the Stewart dynamics model based on the Kane method was established.The correctness of the Stewart dynamics model was verified by the Matlab mathematical model simulation and the ADAMS multi-body dynamics simulation.The MRE material was then tested for its magneto-elastic coefficient and it was proved to have a strong MR coefficient.The MRE material was designed for a new type of MRE damper and it was simulated by using Maxwell finite element software.Finally,the manufacture of the shock absorber prototype was completed and tested in the universal tensile testing machine.The test results showed that the MRE damper has good stiffness and variable damping performance.The joint simulation model of ADAMS and Matlab was established.The stiffness and damping parameter matching results were optimized through the simulation analysis of the DOE.The semi-active control strategy was studied,based on the simulation result and the expert control experience,the fuzzy control algorithm and the PID controller optimization was carried on.Then a adaptive semi-active control with fuzzy PID controller which was suitable for this organization was designed.Finally it was proved that the designed controller which had good control effect through the ADAMS and the Matlab joint simulation analysis.The designed parallel damper mechanism has outstanding multi-dimensional damping performance.It was proved that the mechanism had the advantages of passive control and semi-active control strategy Good damping performance,through manufacturing a prototype of the seat vibration reduction mechanism and testing the vibration reduction performance.The performance of semi-active control was proved to have some extent improved.Simulation analysis and test results show that this design scheme has some feasibility,and it provides a new idea for the research of vehicle vibration reduction seats.