This paper presents a six degree-of-freedom (DOF) real-time motion tracking system of measuring the position and the orientation for industrial robots in three-dimensional (3D) space. The proposed system is based on a typical Stewart platform design and utilizes six low-cost displacement sensors to monitor the motion of the Stewart platform. The advantage of the proposed system is its simple calibration and easy accessibility; the magnetic ball-and-socket joints used for rotational joints. With special measurement tools, the center of rotation of all twelve joints can be measured in 3D space at a glance. Following more than fifty measurements, the average root mean square (RMS) position accuracy error of the proposed device is less than 0.186 mm and the average of angular accuracy error is less than 0.160 °, making it suitable for monitoring the performance of industrial robot. A commercial robot is also tested by the proposed system to verify its usefulness.

中文翻译：

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基于Stewart平台和球窝关节的六自由度运动跟踪系统设计

本文提出了一种六自由度 (DOF) 实时运动跟踪系统，用于在三维 (3D) 空间中测量工业机器人的位置和方向。提议的系统基于典型的 Stewart 平台设计，并利用六个低成本位移传感器来监测 Stewart 平台的运动。所提出系统的优点是校准简单且易于访问；用于旋转接头的磁性球窝接头。借助特殊的测量工具，可以一目了然地在 3D 空间中测量所有十二个关节的旋转中心。经过五十多次测量，所提出设备的平均均方根 (RMS) 位置精度误差小于 0.186 mm，角度精度误差的平均值小于 0.160°，使其适用于监控工业机器人的性能。所提出的系统还对商用机器人进行了测试，以验证其实用性。