Design And Characteristic Research Of Seat Nonlinear Suspension With Integrated Adjustment Mechanism

Design and characteristic research of seat nonlinear suspension withintegrated adjustment mechanismThe working environment of off-road machinery is harsh and complex,which causes multi-dimensional,low-frequency and large amplitude vibration.Long term exposure to this kind of working environment will lead to a variety of occupational diseases,such as back pain.Therefore,the vibration control of off-road machinery has always been the concern of the researcher.As off-road machinery generally has no complete suspension,the vibration reduction mainly depends on the tire,cab suspension and seat system.Among them,the seat system contacts with the human body in a large area,and changing its design parameters has little influence on the performance of the whole machine,so there are many researches on the seat system of off-road machinery.Supported by the National Natural Science Foundation of China(51605184),this paper studies and designs a kind of nonlinear seat suspension,which integrates the height parameter adjustment and weight parameter adjustment mechanisms innovatively.The main work of this dissertation is as follows:(1)The project innovative design and linear mechanism optimization of the seat nonlinear suspension are carried out.An innovative project of seat nonlinear suspension with height and weight parameters adjustment is presented;The mathematical model of linear seat suspension is established based on energy method;According to the mathematical model,optimization variables,optimization objectives and constraints are determined;Then the MATLAB genetic algorithm toolbox is used to optimize the core parameters of linear seat suspension,and ADAMS is used to verify the correctness of the mathematical model and the rationality of the core parameters of linear seat suspension.(2)Modeling and Simulation of static characteristics of nonlinear seat suspension.Bsed on the energy method,the mathematical model of nonlinear roller spring mechanism is established;Based on MATLAB programming,the core design parameters of the nonlinear seat suspension are obtained;Finally,Adams is used to verify the nonlinear theoretical model.(3)The negative stiffness beam is designed based on energy method,and the rigidflexible coupling simulation of the whole seat suspension is carried out.Based on all the core parameters of the nonlinear seat suspension,the seat nonlinear suspension with the mechanism of height adjustment and weight adjustment is designed;the torsion bar is used as the negative stiffness spring creatively,and the roller mechanism of the torsion bar is designed to achieve the nonlinearity;the geometric size of the torsion bar is obtained based on the beam theory,and the stiffness characteristics of the torsion bar are verified by the finite element method;The simulation of rigid-flexible coupling is carried out by ADAMS,which verifies the static characteristics of the designed seat nonlinear suspension.(4)Modeling and analysis of dynamic characteristics of seat nonlinear suspension.Based on the Lagrange equation,a four degree of freedom dynamic model of the seat-human system is established,and then the end-stop characteristics of the designed seat nonlinear suspension are analyzed.(5)Prototype manufacturing,adjustment mechanism and nonlinear static characteristics test.The physical prototype of the seat nonlinear suspension is processed,and the adjustment mechanism and the nonlinear static characteristics of the seat suspension are verified.