The Research Of Control 6 DOF Planar Magnetic Suspension Stage Driven By Linear Motor

Planar magnetic suspension stage is one micro- electromechanical apparatus, which is widely used in semi-conductor processing, circuit board manufacturing, micro-assembling system and so on. Many critical techniques, such as mechanics, electronics, optics, servo driving and automatic control, are concerned in the Planar magnetic suspension stage. The research and manufacture of planar magnetic suspension stage has a very important meaning for manufacture of high performance crystal plate and semi-conducter.A novel planar magnetic suspension stage has been presented in this thesis, a decoupling control approach based on dynamic inversion has used for propulsion of planar magnetic suspension stage system that is a nonlinear, multivariable and strong coupling system. So this method makes the complicated system simplicity and linear, the disturbance has been suppressed by using the disturbance observer. A robust control has used for the suspension of planar magnetic suspension stage. In six freedom positioned stage of high precision, three sets of line servo driving apparatus are adopted. For the loads of movers are not often symmetrical and some unexpected disturbance, the driving apparatus of each freedom is coupled with the others, and the interactional between suspension and propulsion, which makes the system become a complex controlled plant. As to such a complex plant, the dynamic decoupling for each freedom must be done so as to attain the accurate control and satisfy the request of quick and precise positioning. The method of inverse system can realize the dynamic decoupling for the system of multivariate and intensive coupling by state feedback linearization. However, for the difference between the decoupling mode of practical plant and the nominal decoupling mode caused by outer interference and perturbation of model parameters, ideal decoupling is difficult to attain. So, on the basis of decoupling, disturbance observer is designed to proceed compensation. This method is applicable for the practical engineering application. A robust control with input decoupling is used in the controlling part of the magnetic suspension.In this thesis, the method of inverse system is adopted to realize decoupling control for propulsion of the planar magnetic suspension stage of six freedom and line driving, and at the same time, the disturbance observer is used to compensate disturbances. A robust control with decoupling is used for suspension of planar magnetic suspension stage, Those result of simulation shows that the system has good dynamic and static performance and robust character. These schemes meets the request of High-performance control domain and provides some viewpoint for control of planar magnetic suspension stage.