Design of a planar 3-DOF parallel micromanipulator

摘要

A planar three degree-of-freedom (DOF) parallel manipulator is proposed to be applied for alignment during assembly of microcomponents. It adopts a PRR (prismatic-revolute-revolute) mechanism to meet the requirements of high precision for assembly and robustness against disturbance. The mechanism was designed to have a large workspace and good dexterity because parallel mechanisms usually have a narrow range and singularity of motion compared to serial mechanisms. Inverse kinematics and a simple closed-loop algorithm of the parallel manipulator are presented to control it. Experimental tests have been carried out with high-resolution capacitance sensors to verify the performance of the mechanism. The results of experiments show that the manipulator has a large workspace of ±1.0 mm, ±1.0 mm, and ±10 mrad in the X-, Y-, and θ-directions, respectively. This is a large workspace when considering it adopts a parallel mechanism and has a small size, 100 × 100 × 100 mm3. It also has a good precision of 2 μm, 3 μm, and 0.2 mrad, in the X-, Y-, and θ-axes, respectively. These are high resolutions considering the manipulator adopts conventional joints. The manipulator is expected to have good dexterity.