Research On Comfort Simulation And Control Of Human-chair-vehicle Dynamic Model

As an important index to evaluate automotive performance,automotive comfort has attracted wide attention.When considering the automotive comfort index,if the driver and occupant factors are not involved,the comfort will be difficult to meet the design requirements.At the same time,the study of ride comfort through the whole vehicle model is often based on one-dimensional lumped parameter model,which can only capture the vertical vibration response of the occupants,while the human body is a complex mechanical system with elasticity.In order to solve the above problems,a two-dimensional human biodynamic model is coupled with a seven-seat SUV vehicle model to obtain the vertical and longitudinal translational vibration response and pitching rotation vibration response of the occupants,and then more truly simulate the vibration response of the occupants in the vehicle driving state.The specific research contents are as follows:Based on the dynamic analysis of three kinds of two-dimensional body-seat dynamic models,the corresponding mathematical models are deduced and the simulation program is developed.By comparing the transfer functions of three dynamic models,the best twodimensional body-seat dynamic model is selected to provide support for the subsequent construction of seven-seat SUV vehicle model.Build a human-chair-vehicle dynamics model,which is composed of tires,suspensions,car body,seats and human bodies,with a total of 160 degrees of freedom.At the same time,the dynamics of the human-chair-vehicle model is analyzed and the corresponding equations are derived.The road roughness spectrum is generated according to the standard ISO-8608.The purpose of this paper is to provide support for the follow-up study on the comfort of human-chair-vehicle dynamic model.The human-chair-vehicle dynamics model is built by MATLAB/Simunlik software.The effects of road roughness,vehicle speed and seat occupancy on ride comfort are studied,and the acceleration response of car body and seat is analyzed.The simulation results showed that the lower the road roughness grade is,the fewer passengers are,and the lower the vehicle speed is,the worse the ride comfort will be.The vertical acceleration of the car body and seat is greater than the vertical acceleration of the human head.The vertical acceleration of the seat cushion is larger than that of the seat cushion,indicating that the cushion has a great influence on the ride comfort.Based on the human-chair-vehicle dynamics model,the super-twisted sliding mode controller is introduced into the four corners of tire and body.The longitudinal and vertical vibration acceleration and power absorption of the passive suspension and the active suspension with super-twisted sliding mode controller,the legs,buttocks,upper torso,head and viscera of the human body are studied.The results showed that active suspension can effectively reduce the vibration acceleration and power absorption of various parts of the passengers,and then improve the ride comfort of the vehicle.At the same time,active suspension can effectively reduce the longitudinal and vertical vibration acceleration of the car body and improve the ride comfort of the vehicle.The model has certain theoretical significance and research value for the study of ride comfort.