Simulation And Multi-Objective Optimization Of Ride Comfort Of The Ambulance Based On The Effect Of Bumps And Road

The main function of the ambulance is as a temporary emergency place and delivering the injuries rapidly,and plays an important role in medical security and disease prevention and control.Currently,the chassis of domestic ambulance is truck chassis,and the mounts of the stretcher system are rigid supports,this makes the ride comfort of the ambulance stretcher system worse.In recent years,drawing on the experiences from foreign countries,The transportation sector installs bumps on the road,to ensure traffic safety by reducing the speed of the vehicle,making the ride comfort of the ambulance stretcher system worse at the same time.It has a great practical significance to improve the ride comfort of the ambulance stretcher system based on the excitation of bumps and road.At present,the research of the ride comfort of the ambulance stretcher system is still need to be improved.During the existed research,most of them only take into account of the recumbent position,while ignoring the seated driver's vibration,and only consider the ride comfort of the ambulance based on the excitation of road,while ignoring the bumps.The key point of the paper is to establish the vibration model of the ambulance including the driver and the decubital human body,and build the model of bumps and road.The ride comfort of the ambulance is simulated and optimized based on the effect of bumps and road.Specific contents are as follows:(1)The model of the common bumps and road,and the vibration model of ambulanceThe models of nine common bumps based on the different section shape are established,and the model of road of the single wheel is built by filtered white noise method.As derivation the mathematical model of the vibration model is complex,the computer derivation method to build up the vibration model is proposed by using the symbolic operation,based on the analysis of the relationship between the Lagrange equation and the mathematical model of vibration system.Combined with an actual ambulance,the plane vibration model of ambulance is built by using the proposed method,taking into account of the driver and the decubital human body.(2)Simulation ride comfort of ambulance based on the action of bumps and road The excitation model of front and rear wheels of the ambulance established based on bumps and road based on the hysteresis of front and rear wheels.The state equation of ambulance vibration system is derived,and the vibration response of ambulance solved based on the action of bumps and road.The ride comfort of ambulance is simulated by the effect of bumps according to the national standard,and the influence of section shape,section height,and section width to the ride comfort of the ambulance are analysied.The ride comfort of ambulance based on the effect of road is simulated,and the influence of velocity to the ride comfort of the ambulance analyzed.(3)Multi-objective optimization of the ride comfort of ambulance based on Isight The orthogonal experimental design is applied to the ambulance vibration system by using Multidisciplinary optimization software platform Isight,based on the action of bumps and road.The sensitivity analysis is applied to the ambulance vibration system by using the experimental result.The main factors that influence the ride comfort of the ambulance chosed as the optimal variable based on the action of bumps and road.Multi-objective optimization is applied to the ride comfort of the ambulance based on the effect of bumps,road,bumps and road,by using the NSGA-II from Isight,and the different optimization schemes are compared to provide theoretical basis for improve ambulance ride comfort.