Design of a redundant actuated 4-PPR planar 3-DOF compliant nanopositioning stage

The compliant planar positioning stage actuated by voice coil motors can obtain nanoscale motion accuracy within a millimeter motion range and has received increasing attention in precision engineering. However, there is always a contradiction between the actuation force and the output stiffness in the design of the stage. This study presents the design of a novel redundant actuated planar 3-DOF-compliant nanopositioning stage. A redundant actuated configuration can increase the output stiffness of the stage and decrease the peak actuating force. The analytical stiffness model, kinetostatic model, and dynamic model of the stage are established, which illustrate the high force transmission efficiency and dynamic decoupling feature of the stage. The geometric parameters were optimized based on the established models, and model validation and performance evaluation of the stage were conducted via finite element analysis. Finally, a prototype positioning stage is fabricated. Experimental results show that the proposed stage can achieve a motion range of up to & PLUSMN;2.5 mm x & PLUSMN;2.5 mm x & PLUSMN;2.5 degrees with a resolution of 80 nm and 0.28 & DPRIME;, and the tracking error ratio for a composite Lissajous trajectory is within 0.102%.