Rigid 6-DOF parallel platform for precision 3-D micromanipulation

A new type of 6-DOF platform mechanism characterized by very high stiffness and a high degree of accuracy is described. Welded joints connecting the changeable links with the platform and base provide the high stiffness. Hydraulically controlled microactuators use longitudinal elastic deformations for elongation of the legs. Infinitesimal kinematics of a conventional platform, the finite-elements method, and an identification procedure are used for the analysis of the mechanism. Experimental investigations of a pilot set-up of the proposed platform confirmed the predictions concerning the accuracy and stiffness of the proposed device. A practical application of the platform as a secondary table for precise machining on a CNC milling center is described.