Topography Measurement for Monitoring Manufacturing Processes in Harsh Conditions

High precision manufacturing, e.g. milling and grinding, which have manufacturing tolerances in the range of <10 μm require microscopic measurement techniques for the inspection of the manufactured components. These measurement techniques are very sensitive to cooling liquids and lubricants which are essential for many manufacturing processes. Therefore, the measurement of the components is usually conducted in separate and clean laboratories and not directly in the manufacturing machine. This approach has some major drawbacks, e.g. high time consumption and no possibility for online process monitoring. In this article, a novel concept for the integration of high precision optical topography measurement systems into the manufacturing machine is introduced and compared to other concepts. The introduced concept uses a reservoir with cooling liquid in which the measurement object is immersed during the measurement. Thereby, measurement disturbance by splashing cooling liquids and lubricants can effectively be avoided.BMBF/03V047

Position Determination of a Robot End-Effector Using a 6D-Measurement System Based on the Two-View Vision

A mechatronic system based on the micro-macro-kinematic consists of an industrial robot and a piezoelectric stage mounted on the robot’s end-effector and has to carry out operations like micro-assembly or micro-milling. The piezoelectric stage has to compensate the positioning error of the robot. Therefore, the position of the robot’s end-effector has to be measured with high accuracy. This paper presents a high accuracy 6D-measurement system, which is used to determine the position and orientation of the robot’s end-effector. We start with the description of the operational concept and components of the measurement system. Then we look at image processing methods, camera calibration and reconstruction methods and choose the most accurate ones. We apply the well-known pin-hole camera model to calibrate single cameras. Then we apply the epipolar geometry to describe the relationship between two cameras and calibrate them as a stereo vision system. A distortion model is also applied to enhance the accuracy of the system. The measurement results are presented in the end of the paper