Dynamic performance of the SRI Maglev vehicle

The stability and ride quality of a small scale MAGLEV test vehicle were determined by measuring its motions in five degrees of freedom during levitated flight. Various offsets were introduced into the guideway to stimulate strongly different modes of oscillation and to search for instabilities. These offsets, that were up to 25% of the equilibrium suspension height, induced motions that were analyzed to evaluate both passive and active damping systems used on the vehicle. In more than thirty tests of the vehicle, including stimulations of the heave, roll, pitch, yaw, and slip modes of oscillation, no instabilities were observed in any degree of freedom whether using passive or active damping. The active damping system, used in conjunction with the passive system, provided greater stability and ride quality than the passive system alone. The passive system, however, provided enough damping to achieve stability and is therefore a desirable back-up in the event of a failure in the active control system. The tests were simulated on a computer using a completely nonlinear dynamics model and provided good approximations to the data. Extrapolations to full-size vehicles have not been made.