Lqi Optimal Control of Electro-Dynamic Suspension

Magnetically levitated (MAGLEV) vehicle systems have been researched for future high-speed transportation. It is especially important to investigate the dynamic characteristics from the viewpoint of running stability, safety and ride quality at high speed. This paper deals with repulsive-type MAGLEV systems using electro-dynamic suspension (EDS). Although the EDS is inherently stable, the damping force is not large enough to suppress the vibration excited by guideway irregularities and other disturbances. Therefore, this paper investigates theoretically and experimentally the magnetic force control of EDS systems with a hybrid magnet configuration of a permanent magnet and an additional electromagnet, using LQI optimal control theory. The dynamical characteristics are analyzed by an experimental set-up in which a one-degree-of-freedom mass is suspended above an aluminum rotating plate. The computer simulation and experimental results show that the vibration characteristics are greatly improved by the active control, and the optimal control with integral compensation completely eliminates the offset caused by the stationary disturbance.