Comfort Simulation Of Human-chair Dynamics Model And Research On Seat Suspension Contro

Vehicle ride comfort is an important indicator to evaluate car performance and has received widespread attention.Previous research on ride comfort usually focuses on active and semi-active research on automobile chassis suspension,and does not consider the factors of human body and seat,so that the riding comfort of vehicles often cannot achieve ideal design goals.The study of vehicle ride comfort through the human-seat model is often based on the centralized parameter model of rigid seat without backrest support,which cannot truly reflect the vibration response characteristics of various parts of the human body,and also ignores the influence of the seat on the vibration response of the human body.In order to solve the above problems,this paper uses a two-dimensional human biodynamic model,designs different seat back inclination angles to simulate the dynamics of the model,and performs semi-active control of the seat suspension to further improve the riding comfort of the vehicle.The research content mainly includes the following aspects:(1)Establish a human-seat dynamic model and conduct dynamic analysis of each part of the human body,derive the dynamic equation of each part of the human body,simulate the dynamics of each part of the human body by changing the backrest inclination angle of the seat,obtain the vibration transmission rate of different parts of the human body in the longitudinal and vertical direction,and select the seat backrest angle with the best comfort of the human body by comparing the vibration transmission rate under the inclination angle of four different seat backrests,as a mannequin of semi-active control of seat suspension.(2)Through the above analysis,the seat backrest angle with the best comfort is selected to establish the human-seat suspension model,the filtering white noise method is selected to establish the time domain model of random road surface,and the road surface excitation model of B,C and D with a speed of 20m/s and the road surface excitation model with a speed of10m/s,20m/s and 30m/s under the B-level road surface are established,and the filtering of the1/4 vehicle chassis suspension is used as the input excitation of the human-seat suspension model.(3)The basic theory of sliding mode control and the jitter problem of sliding mode control are briefly described and analyzed,and a sliding mode control algorithm with the error of the reference model and the actual model as the sliding mode surface is proposed.For the humanseat suspension system model,the seat suspension controlled by ceiling damping was selected as the reference model.Design an adaptive fuzzy sliding mode controller between the seat suspension and the body.The adaptive algorithm corrects the error of the system model and the interference generated by the outside world to reduce the impact on the control input.In order to improve the robustness of the system.The fuzzy algorithm is used to formulate 49 fuzzy rules to fuzzy control the control parameters,so that the system can reduce jitter under the premise of rapid convergence.The hyperbolic tangent function is used to replace the symbolic function in the switching term,so that the system is more continuous and smoother when the sliding surface reciprocates.(4)Using the simulation software Matlab/Simulink to simulate the controller,random road surface excitation is applied to the seat suspension with semi-active control,and the displacement and acceleration response values of various parts of the human body are obtained.By comparing and analyzing the response output of various parts of the human body controlled by passive suspension,the control performance of semi-active seat suspension is verified.When the vehicle is driving on different road levels and at different speeds,the seat suspension with semi-active control can well reduce the acceleration of various parts of the human body and the corresponding human absorption power compared with the passive suspension without any control,and improve the riding comfort of the people in the car.At the same time,the control effect of the vehicle when encountering bumpy road surface is verified,and the semiactive suspension under impact condition is simulated and compared with the passive suspension.The results show that the semi-actively controlled seat suspension still has good control performance under impact conditions.