The Study On Anti Motion Sickness Of "Suspension-Seat-Occupant" System And Active Control

With the continuous popularization of vehicles and the increasing requirements of people on travel quality,motion sickness(a type of motion sickness)has caused more and more problems for passengers.Although at the level of pathological research,the motion sickness mechanism and prevention methods have received widespread attention from scholars all over the world,but most of them adopt drug treatment methods that have many limitations.Thanks to the early research results of foreign scholars on the impact of motion control on motion sickness,that is,changing the vibration environment to prevent and treat motion sickness,therefore,this article analyzes and studies this motion sickness problem combined with low-frequency motion control theory:Firstly,in view of the close relationship between motion sickness’ s sensitivity to vertical and pitch movements and the movement in this direction and the suspension system,this paper establishes a 7 DOF "suspension-seat-occupant body" mechanical model.Specifically,the active control system composed of the screw motor and the seat rotating motor is controlled by a series of second-order low-pass filtering and the reference model sliding mode variable structure control(RM-SMC)mentioned in this article,to achieve low-frequency(<0.5 Hz)vertical and pitch motion attenuation.Secondly,this article analyzes and models various motion sickness conditions in driving and combines relevant standards to establish the motion sickness index for the vertical and pitch directions of this article.The anti-motion sickness performance of the control system under motion sickness provides the basis,then,using limited acceleration sensors and angle sensors with the Kalman filter algorithm to infer the state of the system as the signal input of the controller.In terms of controller design,an optimal reference model with low-pass filter feedback is considered,and at the same time,the actual suspension system time lag,turbulence and the influence of external disturbance inputs are designed to design the RM-SMC for low-frequency motion.In addition,the stability,tracking performance,and robustness of the suspension control system are simulated and analyzed,and the motion suppression performance in the low frequency band with low-pass filter feedback control is verified.The results show that the proposed controller meets the performance requirements of slow active control in anti-motion sickness systems basically.Finally,this article uses the proposed motion sickness evaluation method as part of the basis for adaptive online adjustment of the suspension system,speculates on the current working conditions,and uses online table look-up interpolation to implement parameter adaptive online adjustment control.The performance of the suspension system is good and the robustness of the suspension system is guaranteed.A large number of simulation results show that for the motion sickness problem caused by low-frequency vertical and pitch motions,the slow active suspension and slow active seat control system designed in this paper,together with the adaptive reference model sliding mode control method,namely Adaptive online adjustment RMSMC,which can effectively suppress low-frequency vibration and ease the growth of motion sickness indicators.In addition,in this paper,the actual car test and hardwarein-the-loop platform simulation were carried out to verify the anti-motion sickness performance under acceleration and deceleration conditions.The research results of this article provide a solution to the motion sickness problem caused by future travel,which has a positive significance for the improvement of future travel quality.