Bringing the Lab to the Fab: Robot-Based Inline Measurement System for Precise 3-D Surface Inspection in Vibrational Environments

This is the authors' abstract. We don't add key points for this paper.

This article presents the integrated design of a robot-based inline measurement system for precise 3-D surface inspection on free-formed objects. The measurement system comprises a MAGLEV measurement platform that is mounted to an industrial robot and enables the out-of-plane tracking of an arbitrarily oriented sample surface. This establishes lab-like conditions for the integrated optical 3-D measurement tool directly in a vibrational environment. Using a proportional-integral-derivative control architecture with a tracking control bandwidth of 600 Hz, the effects of a vibration signal with 15.5μm rms can be reduced to disturbances with 236 nm rms. The orientation-independent measurement performance is demonstrated by imaging a calibration standard with 20μm pitch in various robot poses. Experiments show that the system is capable of reducing the axial measurement uncertainty by a factor of 12, enabling robot-based 3-D measurements with submicrometer resolution on freeform surfaces in a vibrational environment.