Optimization And Control On Variable Cross Track Vehicle Ride Comfort Under Random Excitation

Variable cross track vehicles as an important research and development of advanced agricultural technology and equipment,The key to solve the agricultural production efficiency by land size,planting density,sowing spacing,spacing and other factors limit and working conditions of human-machine operation in two aspects of the problem of fatigue.Agricultural machinery task is mainly caused by nonlinear change of body mass caused by roughness of farm surface and sowing,harvesting and spraying.Vehicle has strong nonlinearity.Paper based vehicle dynamics theory,kinetic theory of gear transmission,modal analysis theory and fuzzy PID control theory,making the best of simulation characteristics of ADAMS,MATLAB\Simulink and ANSYS,treating cross variable track vehicle ride comfort optimization and control as research content.Firstly,time power spectrum density function of road roughness with steep operating frequency was derived and establishing M-File-S time domain model of ridge and furrow road surface was established by using limited bandwidth white noise method.Secondly,torsional vibration of crossover tread of vehicle transmission system with 12 degrees of freedom bending model was established.Under turning condition,mathematical model was combined with the dynamic simulation,the system characteristic parameters were optimized and reasonable dynamic performance index has been achieved.Study on control of stability of power transmission were finished.Treating cross track variable rigid frame body,frame body and wheels as nonlinear vibration damping and modal analysis and vibration under random excitation were conducted.By contrasting simulation analysis and theoretical research and putting forward corresponding suggestions.On the basis of above research,a new damping controlled MR suspension system was designed,optimal design parameters of semi-active suspension system were determined by analyzing the influence of damping ratio,body and wheel mass ratio and wheel and suspension stiffness ratio on vehicle comfort and a fuzzy PID control strategy was established.Results show that MR suspension system can greatly improve cross variable track vehicle ride comfort after optimized and controlled.Moreover,control current of MR damper is obviously consistent with damping force and delay of system response was reduced.