MODELING AND CONTROL OF A MAGNETIC LEVITATION SYSTEM USING AN ANALOG CONTROLLER

[摘要] This paper presents the modeling and control the position of the ferromagnetic ball in a controlled environment using analog controller where the current is varied in the electromagnet to keep the stable position of the ball. Generally, open loop magnetic levitation system is unstable non-linear system. Also, external disturbances are acting on the system making the control is very complex. First, analog controller based magnetic suspension system model is built to represent the dynamic behavior between the current of the electromagnetic coil and position of the ferromagnetic ball suspended. The model is developed using PID controller because it is the most popular industrial controller today. The PID controller is designed using pole assigned method so that pole of the designed system lies on the left half plane. The developed model is simulated using the proposed analog PID controller where step response and frequency response of the system is measured and made the system stable by tuning the proportional, integral and derivative parameter of the PID control. Then, experimental setup of the magnetic levitation system is developed and same control methodology is used to stable the position of the ferromagnetic ball as with simulation. Finally, the position of the levitated ball is suspended using the same control parameter of simulation.

[关键词] Magnetic levitation system;PID control;Analog controller;Electromagnetic force