Experimental Research of Loading Effect on a 3-DOF Macro-Micro Precision Positioning System

The precision positioning technology has developed for a long time and played a significant role in many fields. However, most precision positioning systems designed before only have one or two degrees of freedom, which greatly limits the application. In view of this, a kind of three-degrees-of-freedom (3-DOF) macro-micro precision positioning system is investigated and analyzed in the paper. The macro-micro precision positioning system is designed suitable for application in vacuum environment, which includes two main parts such as 3PRR (3 degrees of freedom, each branch consists of a prismatic pair (P) drive and two rotating pairs (R)) planar parallel platform and piezoelectric micro stage. Before conducting the experiment of macro-micro precision positioning system, it is necessary to investigate the loading effect on the 3PRR planar parallel platform. The loading experiment has showed that different loads have some effect on positioning accuracy and standard variance, but the positioning error is much less than the travel range of micro positioner. Then the experiment combining 3PRR planar parallel platform and piezoelectric micro stage has been carefully conducted by using laser interferometer as feedback control measurement. The experimental results demonstrate that the requirement of high positioning precision and large travel range can be simultaneously met by using the macro-micro precision positioning system.