Online 6DOF metrology with MAPS utilizing a unique aperture pattern mask

The ongoing and ever-increasing demand for high-precision components for specialized applications necessitates increasingly sophisticated and adaptable machine tools. Consequently, industrial robots are frequently employed, despite their limited precision and accuracy, particularly in complex tasks such as the fabrication of free-form optics and ultra-precision mirrors, where high accuracy is key. To enhance the precision, one technique involves tracking the robot’s end effector with an external measuring device to calibrate or correct the robot during operation. The Multi-Aperture Positioning System (MAPS) is a measuring device capable of achieving this. This article proposes a novel methodology for measuring three light sources concurrently with MAPS, employing a pioneering Aperturemask design. The integration of an Arbitrary Aperture Pattern (AAP) with a Template Matching Algorithm (TMA) facilitates the separation of the three measurements in the combined image. Furthermore, the employment of a Nearest Neighbor Algorithm (NNA) enables the establishment of the relationship between the spots and the apertures. This innovative technique facilitates the measurement of the 6DOF of the end effector of machines such as robots while in motion. The creation and validation of different mask designs is facilitated by the MAPS digital twin, and the most optimal design is subsequently manufactured and tested in a laboratory experiment. The MAPS image simulation yields a relative measurement uncertainty of 2.2 ·10⁻⁴, while the laboratory experiment yields 3.5 ·10⁻⁴ (for the worst axis and the best design, respectively).