Study On Nonlinear H∞ Control For Maglev Train

As a perfect vehicle on land, maglev train is characterized by high velocity, less energy consuming, lower noise, safety and comfort. As to the maglev vehicle system, maglev control technology is one of the most nuclear and key techniques in the system. Due to the inherent nonlinearities and open-loop instability of the electromagnetic suspension systems, control of its stability must be accomplished through controller. Linear control theories have provided much of the benchmark design procedures for numerous full-scale vehicles in large test facilities. However, due to constraints of linearization, the resulting time and frequency-domain controllers have restricted capability to cope with significiant changes in the suspended load or large variations in the guideway profile. Based on dissipative theory, robust control theory for nonlinear systems can design a controller whose structure and parameters is unchanged when the controlled system is under the worst conditions and can make the closed loop system maintain the performance with uncertainties. Therefore, the paper put stress on the application of robust nonlinear control theory to maglev vehicle system.In this paper, the mathematical model and the basic structure of the single electromagnet levitation system are discussed firstly. The factors, which influence the performance of the system, will be analyzed and the relative solution will be brought forward for further reference. After that, based on dissipative theory , a nonlinear H_∞ controller is designed and the magnetic suspension system based on the controller is stable and robust.An implementation of the maglev vehicle controller based on DSP is presented. The hardware architecture and software design flow are introduced in detail. The experiment results show the system proposed is reliable and successful.