Digital Control of Magnetic Levitation for Contactless Delivery Applications

In recent semiconductor making processes, high-class clean operations of delivery robots without contacts are required more and more. Magnetic levitation system can be applied to semiconductor fabrication applications, for example, which includes clamp-type robot, linear motors for propulsion, contact-less power supply for power sourcing and magnetic levitations for contact-less bearings. In this paper, electromagnetic suspension vehicle model and its decoupled control method is presented. The symmetry of the geometric configuration and space coordinates transformation techniques are used to eliminate the redundancy of electromagnetic force control. Then, each of the three motion states becomes a single-input and single-output (SISO) linear sub-system and a linear proportional, integral and derivative (PID) controller was designed for each sub-system and tested for the constructed electromagnetic suspension (EMS) vehicle simulator.