イナータを用いた救急車用防振架台の設計

抄録

A vibration-isolating bed for ambulances using an inerter is proposed. The structure of the vibration-isolating bed is assumed to consist of a bottom frame fixed to the ambulance floor and an upper frame on which the stretcher is placed. Both are connected only by the suspension, including the inerter, in the vertical and horizontal directions. Because the inerter can reduce the gain of the high frequency band and delay the response, the time when maximum acceleration is applied to vibration-isolating bed can be shortened in a limited space in ambulance. We consider the vibration-isolating bed as a plant and the designed suspension as a controller, and then formulate the state equation. To reduce the acceleration within the movable range of the bed in ambulance, the controller that minimizes the H_∞ norm of the transfer function from the external force acting on the vibration-isolating bed to vibration-isolating bed acceleration is calculated by bilinear matrix inequality. The transfer function determinates the structure and coefficient of the suspension by assuming that the transfer function is the sum of mechanical admittance of spring, damper and inerter. The usefulness of the vibration-isolating bed is verified by numerical simulations by using MATLAB assuming braking and turning.