A visual six-degree of freedom posture measurement system for evaluation of parallel manipulators using a pyramidal mirror and a phase-encoded binary scale

IF 5.2 2区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Measurement Pub Date : 2025-06-16 DOI:10.1016/j.measurement.2025.118187

Jong-Ahn Kim , Jae Yong Lee , Chu-Shik Kang , Jae Heun Woo

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引用次数: 0

Abstract

We propose a vision-based six-degree of freedom (6-DOF) posture measurement system for evaluating parallel manipulators in precision motion control applications. The system acquires 6-DOF information by capturing four coordinate sets of center points from partial images of a phase-encoded binary scale attached to the manipulator’s moving plate. A monocular vision system, combined with a pyramidal mirror and adjustable beam-steering mirrors, enables optimized lines of sight for improved sensitivity and measurement range. A telecentric lens reduces distortion, and a decoding algorithm enhances accuracy. A self-calibration algorithm further refines precision using redundant coordinates. The system achieved axial stability of 0.04 μm and 0.17″, with posture measurement deviations within ±0.58 μm and ±2.8″ compared to a reference system, representing substantial improvements over best existing method with readout stability of 5.4 μm and 8.3″. Sensitivity to uncertainty sources was analyzed using Jacobian matrices. The proposed system provides a compact, high-precision, and practical solution for in situ calibration and performance evaluation of parallel manipulators and robotic systems.

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采用锥体镜和相位编码二值标度的六自由度并联机器人姿态视觉测量系统

提出了一种基于视觉的六自由度（6-DOF）姿态测量系统，用于评估并联机器人在精密运动控制中的应用。该系统通过从附着在机械手移动板上的相位编码二进制标度的部分图像中捕获四组中心点坐标来获取6自由度信息。单目视觉系统，结合锥体镜和可调光束转向镜，可优化视线，提高灵敏度和测量范围。远心透镜减少了失真，解码算法提高了精度。一种利用冗余坐标的自校准算法进一步提高了精度。与参考系统相比，该系统的轴向稳定性为0.04 μm和0.17″，姿态测量偏差在±0.58 μm和±2.8″之间，比现有的最佳方法（读数稳定性为5.4 μm和8.3″）有了实质性的改进。利用雅可比矩阵分析了对不确定源的敏感性。该系统为并联机械臂和机器人系统的原位标定和性能评估提供了一种紧凑、高精度、实用的解决方案。提出了一种基于视觉的六自由度（6-DOF）姿态测量系统，用于评估并联机器人在精密运动控制中的应用。该系统通过从附着在机械手移动板上的相位编码二进制标度的部分图像中捕获四组中心点坐标来获取6自由度信息。单目视觉系统，结合锥体镜和可调光束转向镜，可优化视线，提高灵敏度和测量范围。远心透镜减少了失真，解码算法提高了精度。一种利用冗余坐标的自校准算法进一步提高了精度。与参考系统相比，该系统的轴向稳定性为0.04 μm和0.17″，姿态测量偏差在±0.58 μm和±2.8″之间，比现有的最佳方法（读数稳定性为5.4 μm和8.3″）有了实质性的改进。利用雅可比矩阵分析了对不确定源的敏感性。该系统为并联机械臂和机器人系统的原位标定和性能评估提供了一种紧凑、高精度、实用的解决方案。

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来源期刊

Measurement 工程技术-工程：综合

CiteScore

10.20

自引率

12.50%

发文量

1589

审稿时长

12.1 months

期刊介绍： Contributions are invited on novel achievements in all fields of measurement and instrumentation science and technology. Authors are encouraged to submit novel material, whose ultimate goal is an advancement in the state of the art of: measurement and metrology fundamentals, sensors, measurement instruments, measurement and estimation techniques, measurement data processing and fusion algorithms, evaluation procedures and methodologies for plants and industrial processes, performance analysis of systems, processes and algorithms, mathematical models for measurement-oriented purposes, distributed measurement systems in a connected world.