Large range parallel compliant pure rotational micropositioning stage driven by two voice coil motors with symmetrical layout.

Abstract

This paper presents the design of a parallel compliant pure rotational micropositioning stage driven by two voice coil motors aimed at achieving high precision and high responsiveness in pure rotation micropositioning. The stage consists of two leaf-spring based driving arms and a pair of symmetric isosceles trapezoidal mechanisms. The parallel structure of the stage can effectively enhance the system's stiffness and response speed. By analyzing the kinematic and dynamic properties of the stage, the design parameters of the stage are determined to meet positioning requirements across various application scenarios. Finite element analysis is then conducted to validate the accuracy of the analytical model. To validate the proposed design, a stage prototype was constructed and subjected to experimental testing. The testing results demonstrate that the stage can achieve a maximum rotation angle of 41.6 mrad. Furthermore, a feedback controller was also designed to validate the system's stability and tracking accuracy. The trajectory tracking experimental results show that the stage exhibits excellent positioning accuracy and dynamic response to both sine and step signal inputs, confirming its potential in the micropositioning field. Finally, the drift of the rotational center of the stage was observed and evaluated under a microscope, validating the good performance of the rotation accuracy of the stage.