Demonstrating the Potential of a Hybrid Model to Increase the 360 Degrees Rotational Motion Freedom of Ironless Permanent Magnet Planar Motors

The ironless permanent magnet planar motors (IPMPMs) are used in the lithography machine to realize long stroke x, y translation with single mover. The lack of rotation motion limits its use in a wide range of applications. This paper proposes a hybrid model for the IPMPM to realize the rotational motion. Based on the decoupling feature, the influence cause by the x, y translation and the rotation can be expressed by the position functions and 1-d lookup table (LUT) respectively. To the coils with centro-symmetry, the hybrid model can be further simplified. Then simulations about the calculation speed and the model accuracy are conducted. Compared with the 3-d LUT, the hybrid model cost less time with relative high accuracy. Finally the validity of the hybrid model is verified by experiment.