A New Design for Active Isolation of Patient's Compartment from Ambulance Body using the Adaptive Control Method

Vertical vibrations in the ambulance patient compartment due to road disturbances can cause serious injury to patients. In the present study, after extracting the vibrations entering an ambulance with passive suspension system, the use of a new active vibration isolation system between the patient's Compartment and the ambulance body is proposed. This isolation system includes an air spring, a linear shaft motor and a suitable active controller, which is abbreviated as AVI system. In this paper, instead of using one AVI system to control the vibrations of the stretcher, four AVI systems are used to control the vibrations of the patient's Compartment. The accurate modelling for ambulance with passive suspension system in both types non-isolated and active isolated patient's Compartment has been done by SOLIDWORKS software. Then by extracting the mathematical model, differential equations and state space model, the comparison of both types was done using MATLAB-SIMULINK software and finally the results were optimized using the Model Reference Adaptive Control (MRAC). In this control method, the functional parameters automatically adapt themselves by changing the position of the centre of gravity. The results obtained according to the IS02631 standard, show that with the present method, vertical vibrations are reduced by more than 80%.