Vibration Isolation Design Of Vehicle Stretcher-supine Body System Based On Wire-rope Spring

In the process of evacuation and medical aid, vibration in transportations ofvehicles may lead the sick and wounded to exacerbations. Generally, ambulancesadopt the rigid axle suspension and the vehicle refitting is costly. Therefore, thevibration reduction design of vehicular stretcher system is the key to solve theproblem of vibration reduction design. In the design, the vibration isolator parametersoptimization is an important approach to realize the vibration reduction effect. Thispaper conduct a research on ambulance vehicular stretcher system analyzes thevibration characteristics of the vehicle-stretcher-recumbent body system optimizes thestiffness, damping and position of vibration isolator parameters.Firstly is the analysis of vibration isolator. The wire-rope spring staticscharacteristic is analyzed based on which the dynamic characteristics is obtained. Theeffects of parameters on the vibration isolation system are computed to get changeswith frequency of the vibration and frequency characteristics under differentexcitation.Secondly, multi-body dynamics modeling of vehicular stretcher is performed onthe basis of previous studies for linear stiffness damping. Considering a stretchersystem vibrating in lateral and vertical directions and the vehicle transportation massproportion, excitation to the bottom floor of the vehicular stretcher with its responsewere calculated.The finally section is the optimization design of the vibration system, whichtarget is comfort evaluation of recumbent human body, the design variables is thestiffness, damping and position parameters of vibration isolator. Usually, theoptimization solution may be fall in locally optimal solution instead of the globaloptimal solution. To solve the problem, set an orthogonal experiment design, get thebest results in several groups as a starting point in optimization, using SimulatedAnnealing (SA) algorithm in the vibration system parameters optimization, finally getthe parameters of the vibration reduction scheme and validate it by designing theexperiment. Results suggest that the model and optimization approach are validated.