Dynamics, control and ride quality of a magnetically levitated high speed ground vehicle

Abstract

MAGNETIC MEANS OF SUSPENDING VEHICLES HAVE BEEN PROPOSED FOR USE IN HIGH SPEED GROUND TRANSPORTATION SYSTEMS. HOWEVER, THE MOTION OF SUCH SUSPENSION (LEVITATION) SYSTEMS USING MAGNETIC REPULSION FORCES WHEN THEY ARE PERTURBED FROM EQUILIBRIUM IS OSCILLATORY WITH A FREQUENCY OF THE ORDER OF 1 HZ AND A VERY LONG DAMPING TIME. ONE MEANS OF OBTAINING MORE DAMPING IS BY FEEDBACK CONTROL OF THE MAGNET CURRENTS. IN THIS PAPER, THE RIDE QUALITY RESULTING FROM ALTERNATIVE CONTROL STRATEGIES USING FEEDBACK PROPORTIONAL TO VEHICLE-TRACK CLEARANCE, VERTICAL VELOCITY AND ACCELERATION ARE CONSIDERED. IT IS FOUND THAT GOOD RIDE QUALITY CAN BE OBTAINED OVER A TRACK EQUIVALENT TO A MODERATELY GOOD HIGHWAY WITH A HIGH CLEARANCE MAGNETIC SUSPENSION. THE DYNAMICS OF A VEHICLE IN ALTERNATIVE GUIDEWAYS WHICH SUPPLY LATERAL GUIDANCE AS WELL AS LIFT FORCES ARE ANALYZED. IT IS SEEN THAT A GUIDEWAY CONFIGURATION WHICH PROVIDES ORTHOGONAL SURFACES FOR GUIDANCE AND LEVITATION FORCES LEADS TO INHERENTLY MORE STABLE VEHICLE MOTION AND ALLOWS THE USE OF SIMPLE INDEPENDENT CONTROL STRATEGIES ON ALL LIFT AND GUIDANCE MAGNETS. /AUTHOR/