Development and Assessment of a Novel Decoupled XY Parallel Micropositioning Platform

This paper presents the development and performance assessment procedures for a new XY parallel micropositioning platform (PMP) aiming at a submicrometer accuracy for microscale manipulation. The uniqueness of the proposed micro-parallel platform lies in that it possesses an uncomplicated structure as well as actuation isolation and output motion decoupling properties, which facilitates the adoption of two single-input-single-output controllers. Based on the matrix method, the kinetostatics models of the PMP are established and verified by finite-element analysis. Via system identification, a digital lag--lead compensator is designed to compensate for the hysteresis of each piezoelectric actuator. A feedforward control is then implemented to construct a zero phase error tracking controller. Positioning performance of the PMP in terms of resolution, accuracy, repeatability, and contouring performances of 1-D and 2-D motions has been evaluated by several experimental studies. Experimental results not only validate the effectiveness of the designed controller but also show that both positioning and contouring of the PMP can achieve a submicrometer precision within a specified velocity range.