Robotic arm operated automatic area scanning phase measuring deflectometry calibration method

Phase measuring deflectometry (PMD) is a key measurement technology for specular surfaces form measurement. With the rapid advancements in the processing and manufacturing of specular workpieces, increasing demands are being placed on the compactness, portability, and flexibility of PMD systems. In most industrial applications, the target surface often exceeds the single field of view of the measurement setup, necessitating multi-view measurements or stitching strategies to obtain complete surface data. Robotic positioning-assisted offers an efficient alternative to traditional fiducial marker-based methods by aligning multiple sub-surfaces within a unified coordinate system. In this letter, a calibration method for a robotic arm operated automatic area scanning PMD technology is proposed. The accuracy of the proposed method is verified through experiments by measuring a ring calibration mirror target. Results demonstrate that the proposed calibration approach enables effective calibration of a robotic arm near optical coaxial PMD. This calibration method lays a certain foundation for expanding the measurement range and flexibility of in-situ measurement of PMD systems.