Design of a high-precision 3D measurement system via multi-source fusion and structural optimization of a Multi-Target Spatial Pose Determination Device (MSPD)

Abstract

To address the trade-off between measurement accuracy, field of view, and efficiency in large-scale dimensional metrology, this paper proposes a high-precision three-dimensional measurement method integrating a laser tracker and a binocular vision system. A Multi-Target Spatial Pose Determination Device (MSPD) is designed to establish a unified global reference frame and a stable pose linkage among heterogeneous measurement data, thereby reducing error accumulation and operational overhead in multi-station measurements. A multi-physics, multi-objective optimization model is formulated for the spatial layout of MSPD targets by incorporating geometric visibility, pose solvability, and structural constraints. The target configuration is optimized using a non-dominated sorting genetic algorithm (NSGA-II) to improve omnidirectional visibility and pose determination robustness. Experimental results show that the optimized MSPD achieves approximately 90% visibility coverage and maintains reliable target identification under varying observation poses. Calibration validation experiments yield a mean reprojection error of 0.1331 mm, confirming the accuracy and repeatability of the coordinate transformation and pose prediction models. Comparative multi-station experiments further demonstrate that, with only one initial calibration, the proposed MSPD-based tracking integration strategy achieves an average point position error of 0.3336 mm and a closed-loop consistency error of 0.2363 mm, while limiting additional operation time per station to 1–2 min. In contrast, station-by-station repeated calibration requires 15–20 min per station, and feature-based alignment exhibits significant error accumulation. These results indicate that the proposed fusion measurement framework provides an effective balance between accuracy, robustness, and operational efficiency, making it suitable for engineering-scale measurement of large and complex components and high-precision robotic calibration.