LeagTag: An Elongated High-Accuracy Fiducial Marker for Tight Spaces

Fiducial markers enable reliable service robot control. In human-robot coexistence environments, efficient placement of square or circular markers can be challenging due to limited space. In this study, we developed a world- first, elongated fiducial marker, capable of high-accuracy 6- DoF measurements, designed to be installable in tight spaces. We introduced two types of lenticular angle gauges to en- hance pose estimation and developed new marker patterns and measurement algorithms to maintain recognition distance and accuracy. The proposed marker achieved a measurement accuracy of 0.1% position error and 0.5◦orientation error. This technology will enhance the practicality and applicability of fiducial markers, contributing to the creation of robot-friendly space for future service robots.