Control Strategies and Motion Planning for Nanopositioning Applications with Multi-axis Magnetic-levitation Instruments

Control Strategies and Motion Planning for Nanopositioning Applications with Multi-Axis Magnetic-Levitation Instruments. (May 2007) Huzefa Shakir, B. Tech. (Honors), Indian Institute of Technology, Kharagpur Chair of Advisory Committee: Dr. Won-jong Kim This dissertation is the first attempt to demonstrate the use of magnetic-levitation (maglev) positioners for commercial applications requiring nanopositioning. The key objectives of this research were to devise the control strategies and motion planning to overcome the inherent technical challenges of the maglev systems, and test them on the developed maglev systems to demonstrate their capabilities as the next-generation nanopositioners. Two maglev positioners based on novel actuation schemes and capable of generating all the six-axis motions with a single levitated platen were used in this research. These light-weight single-moving platens have very simple and compact structures, which give them an edge over most of the prevailing nanopositioning technologies and allow them to be used as a cluster tool for a variety of applications. The six-axis motion is generated using minimum number of actuators and sensors. The two positioners operate with a repeatable position resolution of better than 3 nm at the control bandwidth of 110 Hz. In particular, the Y-stage has extended travel range of 5 mm × 5 mm. They can carry a payload of as much as 0.3 kg and retain the regulated position under abruptly and continuously varying load conditions.