Design and Testing of a Damped Piezo-Driven Decoupled XYZ Stage

Lightly-damped dynamics of a flexure-based mechanism will tend to largely deteriorate the broadband control performance if its hysteresis nonlinearity has been compensated. This paper developed a novel damped piezo-driven decoupled XYZ nanopositioning stage, which consists of three orthogonal parallel kinematic subchains, in which each subchain has a translational pair using a bridge-type piezo-driven actuator and two Cardan joints using two orthogonal- axis flexure hinges. Especially, we add damped inserts into each Cardan joint, as their shearing damping effects can enhance joint damping. Kinematic coupling is theoretically modeled and the decoupled dynamic model of the stage is built up. The frequency response functions with no-damping and damping scenarios are obtained by finite element transient analysis and experimental modal analysis respectively. The results indicate that the damping inserts embedded in the flexure hinges can enhance the stiffness and damping simultaneously, which will benefit broadband motion control of the nanopositioning stage.