Investigation of a compliant precision positioning stage with folding function

A foldable compliant XY precision positioning stage with good decoupling property in both axes is developed for precision applications. The compliant rolling-contact element (CORE) is innovatively incorporated in the design of the stage to realize the folding function for compacting the mechanism structure. The input stiffness of the motion platform is determined using the matrix method and is verified by a conventional stiffness modeling method. Finite element analysis (FEA) simulations of three bridge-type amplifiers are conducted and compared to determine the preferable one for magnifying the limited output displacement of the actuator. A foldable stage is then assembled and its decoupling capability and dynamic performances are investigated with the ANSYS software. In addition, a prototype is fabricated to experimentally test the performance of the stage. Results demonstrate that the employed proportional-integral-derivative (PID) feedback controller can settle in 70 ms without overshooting. The closed-loop controlled stage is able to reach a resolution of 2 μm and has small tracking errors within ± 1 μm in the circular-contouring tests.