Accurate and robust optical 3D position control in microassembly using fluorescent fiducial marks

Abstract

The main aim of this work is to allow the automated but nevertheless flexible sensor guided micro assembly with a new 3D vision sensor. The practical application of the sensor guided assembly of micro systems is realised with a special micro assembly system, which contains a parallel robot, an innovative 3D vision sensor, micro grippers and workpiece fixtures. The 3D vision sensor, which is arranged directly above the assembly place and moved synchronized to the micro gripper, makes the uninterrupted observation of the workpiece and the determination of its position possible, in this way allowing the sensor guided assembly of micro systems and a detailed analysis of the principles in the micro assembly process. The basic principle of this photogrammetric measurement concept is given through the fiducial marks. The circular fiducial marks will be realised within the photolithographic production of the components. Using these fiducial marks it is possible to measure the relative position of the components during assembly without reference to their exterior shape.