Robust Control Algorithms For Magnetic Levitation Control System

Electromagnetic levitation technology is a high-tech mechatronics technology. Because its research objectives are high-speed and precision, it has the characteristics of zero friction, zero wear, long service life, low power consumption, low noise, etc. The magnetic levitation control system is a typical non-linear open-loop unstable system, magnetic levitation control system have model perturbation and a variety of outside interference during operation,for example, load, shock, vibration, etc. Traditional PID control is difficult to meet good control performance. Robust control is to design a fixed controller to control the object with some uncertainties meet certain control quality. Therefore, carrying out the study of robust control method for magnetic levitation has an important significance.By summarizing the existing research on magnetic levitation control system, finding that direct application of nonlinear control method and linear method for the uncertainties of the magnetic levitation system is relatively small. So, firstly, the theory of nonlinear control theory based on the dissipation theory is introduced to the magnetic levitation system and a nonlinear H∞controller is applied to magnetic control system; And then, designing a conventional integral sliding mode variable structure controller for magnetic levitation control system; At last, introducing a integral sliding mode control algorithm based on H∞control to optimization of a simple integral sliding mode controller.In order to verify the validity of the used algorithm, simulation and experiment is obtained by Matlab/Simulink tool respectively. Through the comparison of these three algorithms finding that integral sliding mode controller based on H∞control can improve the performance of the integral sliding mode controller largely and have a superior dynamic performance than nonlinear H∞controller.