Controlled Dynamic Characteristics of Ferromagnetic Vehicle Suspensions Providing Simultaneous Lift and Guidance

Static and dynamic analytical models are derived for an attractive ferromagnetic vehicle suspension. The suspension consists of a pair of laterally offset electromagnets, reacting with an inverted U-shaped iron rail, which are controlled using the sum and difference of the magnet pair currents to achieve simultaneous lift and guidance. The control currents are generated from relative gap displacement and absolute vehicle velocity and acceleration signals through an algorithm which yields minimal heave-sway coupling. The analytical models have compared favorably with experimental data from a small scale heave-sway motion test facility. Parametric design studies conducted with the models and experimental data show that adequate guidance forces can be obtained from laterally offset magnets with only small increases in suspension weight and power compared with lift-only magnets.