Robotic precision 3D measurements in vibration-prone environments enabled by active six DoF sample-tracking

Abstract

This paper presents a six degree of freedom (DoF) active sample-tracking robotic 3D measurement system for inline applications. The integrated measurement platform (MP) of the state-of-the-art system is augmented by a compact and tailored in-plane tracking sensor system. Based on two position-sensitive devices and laser markers, relative motion between the 3D measuring tool on the MP and a sample surface is measured with sub-micrometer resolution. Applying a tailored high performance PID control architecture, a six DoF sample-tracking control bandwidth of about 450 Hz is achieved. In a translational in-plane DoF, vibrations with a dominant component at 66 Hz are reduced from 9.44µm rms by a factor of 10 to 931 nm rms. Experimental results successfully proof the system concept of robotic 3D measurements with sub-micrometer precision directly in a challenging vibration-prone environment.