Abstract Photogrammetry-based motion tracking systems are widely used in entertainment, medicine, sports, and other industries for low accuracy positioning applications. Camera-based systems track cooperative markers on objects to obtain their real-time positions and poses. There are few detailed studies in the literature on the metrological performance in three-dimensional (3D) space for such systems since they were primarily used in the entertainment industry and their off-the-shelf accuracy was not a key concern. However, applications for these systems have become more widespread due to their low cost and high repeatability (on the order of a few micrometers), and there is promise for applicability in metrology grade applications after suitable modifications. In this context, we investigate the error sources of a motion tracking system by error mapping in 3D space using a coordinate measuring machine (CMM) with two orders of magnitude lower positioning error. With the understanding gained from this study, we propose three different methods to improve the accuracy of motion tracking systems: interpolation based on an experimentally determined error map, error correction based on scale bar measurements, and weighted averaging using two motion tracking systems. Verification experiments are presented for each method. Our study is focused on the baseline errors of the motion tracking system, i.e., the system is used in the static mode where the coordinates are recorded when the probe (composed of markers) is stationary, not moving.

中文翻译：

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提高运动跟踪系统尺寸测量精度的方法

摘要 基于摄影测量的运动跟踪系统广泛应用于娱乐、医学、体育等行业的低精度定位应用。基于相机的系统跟踪对象上的协作标记以获得它们的实时位置和姿势。文献中关于此类系统在三维 (3D) 空间中的计量性能的详细研究很少，因为它们主要用于娱乐行业，并且其现成的准确性不是关键问题。然而，由于这些系统的低成本和高重复性（几微米的数量级），这些系统的应用变得更加广泛，并且在经过适当修改后有望应用于计量级应用。在这种情况下，我们使用坐标测量机 (CMM) 在 3D 空间中通过误差映射来研究运动跟踪系统的误差源，该坐标测量机具有两个数量级的低定位误差。根据从这项研究中获得的理解，我们提出了三种不同的方法来提高运动跟踪系统的精度：基于实验确定的误差图的插值、基于比例尺测量的误差校正以及使用两个运动跟踪系统的加权平均。每种方法都提供了验证实验。我们的研究集中在运动跟踪系统的基线误差上，即该系统用于静态模式，其中当探头（由标记组成）静止而不是移动时记录坐标。