High-speed and precise positioning of an X-Y table

Positioning plays an important role in manufacturing machines. This work presents a novel two-step controller strategy to achieve fast and precise positioning at the same time on an X-Y table that moves across the macro-dynamic range and settles to within the micro-dynamic resolution. The model dynamics in the macro- and the micro-region are both discussed and the controller design is separated into two parts to satisfy the requirements in each region. The switching condition of the controller is well defined. Experimental results indicate that the proposed two-step controller can move the system from the macro-region into the micro-region in 0.2 s with. an accuracy of 1 mum. (C) 2002 Published by Elsevier Science Ltd.