A spatial hybrid motion compliant mechanism: Design and optimization

A hybrid motion system is defined as a mechanical system that combines a macro motion and a micro motion into one system to achieve a large motion and high resolution with fast response simultaneously. In this paper, a spatial hybrid motion mechanism with 3-DOFs is developed that integrates two types of motion through only one compliant mechanism: a macro motion driven by DC servomotors for large workspace and a micro motion driven by PZT actuators for high precision. A unique feature of the developed hybrid motion compliant mechanism is the elimination of coupling interaction between the macro motion and the micro motion by properly structure design. Three issues are addressed in this paper: (1) design principle and implementation of the hybrid motion mechanism; (2) kinematic analysis and dynamic analysis; and (3) optimization design of the hybrid motion mechanism. A spatial hybrid motion mechanism is developed and the optimization is conducted. The Taguchi method is used to identify significant parameters in the design optimization, and finite element analysis results verify the design principle of the parallel architecture for the hybrid motion mechanism.