Decoupling and levitation control of a six-degree-of-freedom magnetically levitated stage with moving coils based on commutation of coil array

Abstract

The research in the present paper focuses on decoupling the six-degrees-of-freedom motions of a magnetically levitated stage with moving coils and controlling the levitation motion. The decoupling is based on commutation of coil array, which is obtained reversely from the electromagnetic force/torque model of the stage. The control of levitation motion is carried out by a phase lead-lag controller designed on the criterion of minimum integral of time-weighted absolute error after gravity compensation modeling of the plant dynamics. Comprehensive simulations of the control system in MATLAB/Simulink and real levitation experiments on a digital signal processor-centered test platform are made to verify the six-degrees-of-freedom decoupling effect and the closed-loop control performances of the levitation degree of freedom. The results indicate that the six-degrees-of-freedom motions of the stage can be decoupled through coil array commutation and the levitation motion can be controlled by the phase lead-lag controller based on the gravity compensation model and designed on the criterion of minimum integral of time-weighted absolute error.

Keywords

Decoupling levitation control commutation of coil array gravity compensation modeling phase lead-lag controller magnetically levitated stage

Get full access to this article

View all access options for this article.

References

Kim

Trumper

Jeffrey

. Modeling and vector control of planar magnetic levitator. IEEE Trans Ind Applic 1998; 34(6): 1254–1262.

Kim

. Nanoscale dynamics, stochastic modeling, and multivariable control of a planar magnetic levitator. Int J Contr Autom Syst 2003; 1(1): 1–10.

Kim

. Controller design and implementation of six-degree-of-freedom magnetically levitated positioning system with high precision. Proc IMechE, Part I: J Systems and Control Engineering 2008; 222(8): 745–756.

Compter

. Electro-dynamic planar motor. Precis Eng 2004; 28(2): 171–180.

Van Lierop

CMM

Jansen

Damen

AAH

. Control of multi-degree-of-freedom planar actuators. In: 2006 IEEE international conference on control applications (CCA 2006), Munich, Germany, 4–6 October 2006, pp.2516–2521. New York: IEEE.

Van Lierop

CMM

Jansen

Damen

AAH

. Model-based commutation of a long-stroke magnetically levitated linear actuator. In: Conference record of the IEEE industry applications conference 41st annual meeting, Tampa, USA, 8–12 October 2006, pp.393–399. New York: IEEE.

De Boeij

Lomonova

Vandenput

AJA

. Modeling ironless permanent-magnet planar actuator structures. IEEE Trans Magn 2006; 42(8): 2009–2016.

Min

Zhang

Zhu

. Analysis and optimization of a new 2-D magnet array for planar motor. IEEE Trans Magn 2010; 46(5): 1167–1171.

Jansen

Van Lierop

CMM

Lomonova

. Modeling of magnetically levitated planar actuators with moving magnets. IEEE Trans Magn 2007; 43(1): 15–25.

10.

Zhang

Zhu

Yin

. Coil array real-time commutation law for a magnetically levitated stage with moving-coils. J Mech Eng 2011; 47(6): 180–185.

11.

Xue

. Simulation and computer aided design of control system. 2nd ed. Beijing: Machine Press, 2009.

12.

. Automatic control principle. 5th ed. Beijing: Science Press, 2007.