Design and Analysis of A 2-DOF Parallel Mechanism for Space Large Deployable Antenna

The space thermal environment and sophisticated deployable structure lead to the error of the satellite antenna. In this paper, a parallel-kinematic symmetrical stage to eliminate the error of antenna is proposed to realize the 2-DOF rotation with compact physical size. The flexure Hooke hinge is utilized to replace traditional U-joint with its characteristic of distributed compliance to eliminate the rotation clearance and to improve precision. This parallel mechanism is constituted of two symmetrical chains which are UPS kinematic chains with one spherical joint(S), one ball screw prismatic(P) and one flexure Hooke hinge(U) and one fix chain. Geometric analytical method is implemented to establish the kinematic model and the resolution of the parallel mechanism. A prototype stage is fabricated for experiment study. The open-loop testing is conducted to validate the stage's performance. Result show that the 2-DOF parallel mechanism possesses a compact dimension, which offers a workspace of ±2°×±2° with the repeatability precision of 0.01°.