Abstract
A vehicle magnetically levitated with attractive forces is designed to have a very narrow clearance between the electromagnets and the guideway. It is a very important concern that a collision may take place between the magnets and the guideway. To deal with this problem, we must analyze the dynamical characteristics of vehicles running over the guideway having irregular surfaces. Practically, the guideway is composed of two tracks for suspension. But in the paper so far published on this problem, the authors have dealt with only one track irregularity. Although it is geometrically and dynamically important to consider the torsion of the guideway plane surface which is caused by two track irregularities, they have overlooked it. This may be because no guideway model of multiple irregularities based on the experiment has been established.
Therefore the purpose of this paper is to describe the mathematical model of the guideway surface irregularities which are the statistical inputs of the vehicle dynamical model. Main contents are as follows. (1) The theory of a stationary gaussian random process can be related to the guideway surface irregularities, such as vertical, rolling and torsional irregularities which are all measured by the high speed instrument vehicle. (2) The statistical model with power spectral densities proposed here is reasonable and practical enough to be applied to the experimental result by V. Bormann. (3) The time series of guideway irregularities can be realized by an AR-MA model. The procedure to obtain the AR-MA model is shown, and the resulting time series is also shown to be practically efficient.