Design of a novel rotary micropositioning stage with remote center of motion characteristic

High precision rotational alignment is of key importance in micro/nanopositioning or micromanipulating applications. This paper presents a novel rotary micropositioning stage with remote center of motion (RCM) characteristic. Compared with conventional rotary guiding mechanism, the proposed double-parallelogram mechanism (DPM) possesses pure rotational motion along with a compact structure. Based on the DPM, a compact rotary micropositioning stage with RCM characteristic is then proposed. The operating space of the stage can be enlarged by adjusting the input angle without any loss of precision. And the center shift of the stage is kept in a small level due to the pure rotation motion of the DPM. Pseudo-rigid-body (PRB) method is employed to preliminarily model the kinematics and dynamics of the system. The analytical model is validated by conducting finite-element analysis (FEA). Both the analytical model and FEA results have confirmed the effectiveness of the design, which indicates that the proposed mechanism can meet the requirements for micromanipulations or precision aligning applications.