Design evaluation of a single-axis precision controlled positioning stage

This paper presents the design and control of a single-axis positioning stage with a total travel of 50 mm. The single-axis stage is comprised of a long-range slideway, running on ultra-high molecular weight polyethylene (UHMWPE) bearings, and a short-range positioning stage, comprised of a PZT driven flexure. Feedback errors associated with the long-range stage are reduced by the short-range stage, mounted on top of the long-range stage. Within the evaluation of the long-range stage, two alternative drives are assessed; a Roh’lix® and a feedscrew drive. To determine the effects of dynamic interaction between the two drive systems, a further assessment of the single-axis stage was undertaken with the short-range stage operating at different bandwidths, ranging from 91 Hz to 2188 Hz. At the highest bandwidths, nanometer performance is demonstrated for a sinusoidal displacement demand corresponding to sinusoidal traverses of 1 mm and 5 mm with a maximum velocity of approximately 30 μm s−1 and 150 μm s−1, respectively. Furthermore, a 12 nm RMS controller error over a traverse of 25 mm at a maximum velocity of approximately 330 μm s−1 was observed with the use of the feedscrew drive only.