The Nonlinearity model of magnetic levitation system was established with the experimental fitting curve between the ball position and the control circuit by S-function in MATLAB.Combining both the advantages of PID controller and fuzzy controller

an improved fuzzy adaptive PID controller(IFPID)was proposed aiming at open-loop instability and strong nonlinearity of maglev system.The algorithm of IFPID controller adopted nonlinear fuzzy of position deviations E and variation rates of deviation Ec

and separated D controller from PID controller while P and I parameters were adapted by fuzzy controller.The simulation results show that the IFPID controller has the advantages of higher anti-interference ability and adaptability than the conventional PID controller

and better dynamic property and stability.