Sliding-Mode Control of an Electromagnetic Actuated Conveyance System Using Contactless Sensing

A microcontroller-based conveyance system using a hybrid electromagnetic suspension (EMS) system and a linear synchronous motor (LSM) is proposed. Unique placements of the hybrid EMS and LSM integrated with an array of infrared sensors, embedded microcontroller, and electronics switching circuits are designed to maintain the air gaps and the propulsion. To improve the air-gap stability, a robust sliding-mode feedback controller is used. The entire control system is implemented, simulated, and verified by experimental measurements. As compared to different control schemes such as the H-infinity and the proportional-integral-derivative controller, it has shown to give reasonable performance under certain parametric uncertainties.