Design and simulation of a magnetic levitated switched reluctance linear actuator system for high precision application

Abstract

Magnetic levitated carrier system was developed for the transportation systems. It is contact-free type; it can eliminate mechanical components (e.g. gears, guide, ball bearings), reduce the mechanical alignment and maintenance cost, satisfy environmental demand, and enable the carrier to travel at high speed with high precision and acceleration. In this paper, the investigation, design, simulation and fabrication of a magnetic levitated linear motion system are addressed, based on switched reluctance (SR). The proposed system resolves the problems of mechanical wear, friction, noise, heat generation, and ldquometal dustrdquo contamination, and it is very suitable for applications that require high-performance linear motions: from high-precision manufacturing machines, clean-room wafer carrier systems, to high-speed material transportation in factories and warehouses. The proposed system employs a novel linear machine structure which uses four coils for levitation, and three coils for propulsion. Comparing to permanent-magnet (PM) track levitation, high-temperature superconductor levitation, and other existing magnetic levitation methods, the proposed system has a much simpler structure. It can lower manufacturing cost and increase reliability. In this paper, we firstly discussed the mechanical structure of the proposed levitation system and the model of the actuators. Then, finite element analysis (FEA) was carried out for both the propulsion and levitation actuators to verify the electromagnetic characteristics of the motion system. Finally, a control algorithm, which includes PID and nonlinear force control was discussed. The levitation system was simulated by Matlab Simulink, to achieve a stable and high-precision position control. The simulation results were very satisfactory and it validated the design concept.