Design Of A Semi-active Seat Suspension And Its Multi-dimensional Vibration Damping Research

With the increasing demand for vehicle riding comfort,more and more attention has been paid to how to improve seat damping performance by new seat suspension.Based on the domestic and foreign existing seat suspension and related researches,starting from the demand of automobile seat vibration,put forward a new multidimensional semi-active seat suspension,which is based on a three DOFs parallel tensegrity mechanism,and the corresponding control strategy based on the simulation results of the damping performance is verified.Firstly,based on the requirement of seat damping,the three DOFs tensioning integral parallel mechanism is constructed as the main body mechanism of the multi-dimensional semi-active seat suspension.According to the reference range of vehicle seat suspension and the motion / force transmissibility index of the elastic leg,the main configuration size of the main body of the seat suspension is determined,and workspace and velocity mapping relationship of the main body are calculated.Secondly,based on the virtual work principle,the mapping relationship between the stiffness matrix and the motion stiffness matrix of the upper part of the multi-body seat suspension passive vibration absorber is derived,and the stiffness characteristics of the passive damping mechanism are analyzed.The kinematic mapping and force mapping relationships between the driving branch and the constrained branch joints of the multi-dimensional seat suspension mechanism are analyzed.Based on that,a dynamic model of the simplified human seat car body model is established.Thirdly,the influence of the spring stiffness and damping elements of the elastic support leg on the damping performance of the passive damping mechanism is studied by using the virtual prototype of the passive vibration damping mechanism,and then the nonlinear characteristics of the passive damping body mechanism are studied through vary amplitude excitations.The response of the passive vibration damping body under the compound random excitation is simulated and the root mean square value of the random response displacement is evaluated.Finally,a semi-active damping multidimensional semi-active seat suspension control strategy is proposed,and a multidimensional joint simulation model of semi-active seat suspension is established.Frequency response characteristics of the seat suspension under semi-active control are simulated and compared with those under passive model.Response characteristics to impulse under semi-active control is researched in time domain.Simulation test is conducted to understand the response of semi-active seat suspension in composite random excitation,and the simulation results are compared with passive response and damping mechanism of random vibration results.