Dual-axis Maglev guiding system modeling and controller design for wafer transportation

We extend our previous result (1999) on designing a single-axis Maglev guiding system into a more involved work of designing a dual-axis positioning system. First of all, important issues on how to construct the mechanism of the dual-axis positioning system are addressed, Then, the dynamics of the dual-axis Maglev guiding system are analyzed. According to the derived analytic model, which is subject to unknown system parameters, an adaptive controller that can control the wafer carrier at the desired target point of each axis with full alignment is developed. From the simulation results, good performance of regulation for the guiding-axis and of tracking for the positioning-axis is achieved.