Design and construction of single axis electromagnetic levitation system using fuzzy control method

Magnetic levitation (Maglev) is the most attractive subject in control engineering having nonlinear property. Single –axis electromagnetic suspension system is the first stage of maglev train which is one of the most important applications of this phenomena. In this thesis, mathematical model and control of single-axis electromagnetic suspension system is introduced in details. The mathematical model of the system contains second order polynomial because of magnetic force equation. Therefore, this system is nonlinear. Taylor series expansion method is used to linearize the nonlinear equation. Fuzzy logic control is designed to control the linearized unstable system. Two circuits are used to test the controller algorithm, the first circuit is Hilink platform (hardware-in-the-loop real-time control platform for Matlab/Simulink) offered by Zeltom company which is used as interface between physical plants and Matlab/Simulink. The second circuit is based on microchips' dsPIC30F4011 microcontroller and is used to process measurement data and generate the control signals. Hall-effect sensor is selected to sense the permanent magnet position. A permanent magnet ball is successfully levitated at the certain set position with desired performance criteria against gravity force. In addition Hybrid control also was tested and succeeded with the HILINK platform circuit. Hybrid control is a new type of control that mixes the classical control like phase lead control and intelligent control like fuzzy logic control to get better results from each of them. Keywords: magnetic levitation, Maglev, electromagnetic suspension, EMS, Hall effect sensor, HILINK, Fuzzy logic control, Hybrid control, dsPIC30F4011.