Inverse kinematic modeling of a coupled flexure hinge mechanism

An inverse kinematic model of a micro-motion stage with three degrees-of-fr eedom motion is presented. The XY theta stage uses three piezoelectric actu ators and a monolithic flexure hinge mechanism which is designed to provide large theta motion. The stage design has a coupled hinge mechanism which c auses a difficulty in motion control. This paper describes a computer based inverse kinematic model of hinge mechanism and the experimental verificati on for the model. In particular, it presents a kinematic calibration proced ure for improving the accuracy of the model. It is shown that the simulatio n and experimental results are very similar to each other and they also dem onstrate that the inverse kinematic model can be used for open loop control of the stage within 5% error. The open loop control of the stage provides 7.6 and 8.2 nm positioning resolution over the total range of 41.5 and 47.8 mu m along the X- and Y-axis, respectively, and 0.057 arcsec rotational re solution over the total range of 322.8 arcsec about the theta-axis. (C) 199 9 Published by Elsevier Science Ltd. All rights reserved.