Development of 1-ton magnetically suspended vehicle using controlled d.c. electromagnets

Several methods of supporting passenger-carrying vehicles by electromagnetic suspension are being proposed. The University of Sussex has developed a 1-ton 4-passenger vehicle with controlled d.c. electromagnets, operating on a 30 m track, Britain´s first. Apart from the effort devoted to developing special amplifiers, transducers, magnets and other components, an analytical base for the design of such vehicles has also been established. Different strategies for the control systems allied to new transducers, effects of interaction between control systems of magnets at each corner of a chassis and possible ways of eliminating such interaction, new magnet geometries and their influence on route changing capability and in turn reliability of such vehicles are discussed in the paper. Vehicles using controlled d.c. electromagnets for suspension show promise of vehicle systems possessing the high reliability necessary for high-frequency operation. Such systems could be comparable in capital and operating costs to alternative forms of guided public-transport systems, and with careful design could also be nonintrusive, fitting into the existing fabric of cities and be highly attractive to passengers. The paper may be of wider application to frictionless bearings and instrument suspension and to other aspects of control and electrical-engineering science.