Precision Control of Planar Motion Stages

Planar motion stages actuated by planar motors, which can generate XY in-plane motions, have the advantages of direct drive, high speed, non-contact levitation and simple structure. Such kinds of stages, however, are sensitive to interferences between axes, modeling uncertainties and disturbances because there are no mechanical restrictions in the XY plane. Conventional stage controllers based on classical control methods cannot achieve satisfied positioning performance for the stage. This book presents the design and implementation of precision motion control strategies for the planar motion stages. For ultraprecision positioning applications, dynamics modeling, decoupled control, sliding mode observer- based compensation and performance evaluation for the surface motor-driven planar motion stage are presented. For precision positioning applications, dynamic modeling, sliding mode observer-based control and hybrid sensorless control for the Sawyer motor-based planar motion stage are discussed. The authors believe this book can be a useful reference on precision motion control of planar motion stages or other types of precision positioning systems.