AI 中文总结
该研究针对运动动作分析中关节角度测量问题，提出同步多IMU可穿戴系统及端到端管道，结合多种技术实现关节角度估计，经多实验验证，具有实用、时间一致、成本低等优点，可用于高动态环境下多关节技术分析。
AI 中文摘要
在实验室外环境中进行可靠的关节角度测量对于运动和康复中的姿势评估及技术分析很重要。然而，可穿戴惯性测量单元（IMU）系统虽实用，但仍受漂移、多传感器时间一致性、验证和成本的限制。本文提出了一个同步、经济高效、模块化的IMU可穿戴平台以及一个用于关节角度估计的端到端管道，专门针对高动态运动分析。该系统结合了高速传感与强大的本地日志记录，采用实时时钟校准的微秒时间戳方案进行节点间同步，基于间接卡尔曼滤波器的方向估计器随后进行相对旋转关节角度提取、高通漂移缓解和范围归一化。基于参考的验证使用标准化的坐姿膝盖屈伸协议，将IMU得出的膝盖轨迹与从YOLOv11计算出的无标记视觉参考进行比较。所提方法重现了预期的14周期运动并实现了低归一化误差。通过长时间（2小时12分钟）的刚体肘部保持进一步评估仪器性能，产生接近零的漂移（$r_{\mathrm{drift}}=1.5\times10^{-6}$度/分钟）和实际噪声限制分辨率$0.6442^\circ$。该系统还在高动态挺举任务中进行了演示，两名参与者（专业和业余）连续进行五次挺举。测量的肘部和膝盖轨迹保留了与阶段相关的特征和快速瞬态以用于技术解释，同时通过瞬态时间和轨迹规律性的差异实现专业水平的区分。总体而言，结果支持所提系统作为一种实用、时间一致且经济高效的可穿戴方法，用于高动态环境下的多关节技术分析。
英文摘要
Reliable joint-angle measurement outside laboratory environments is important for posture assessment and technique analysis in sports and rehabilitation. Yet, wearable IMU systems, despite being the most practical solution, remain constrained by drift, multisensor timing consistency, validation, and cost. This paper presents a synchronized, cost-efficient, modular IMU wearable platform and an end-to-end pipeline for joint-angle estimation tailored to high-dynamic sports motion analysis. The system combines high-rate sensing with robust local logging, a Real Time Clock-disciplined microsecond timestamping scheme for inter-node synchronization, an indirect Kalman filter-based orientation estimator followed by relative-rotation joint-angle extraction, high-pass drift mitigation, and range normalization. Reference-based validation used a standardized seated knee flexion-extension protocol, comparing IMU-derived knee trajectories against a markerless vision reference computed from YOLOv11. The proposed method reproduced the expected 14-cycle motion and achieved low normalized error. Instrumentation performance was further evaluated using a long-duration (2h 12min) rigid-body elbow hold, yielding near-zero drift ($r_{\mathrm{drift}}=1.5\times10^{-6}$ deg/min) and a practical noise-limited resolution of $0.6442^\circ$. The system was also demonstrated on a high-dynamic clean & jerk task with two participants (professional and amateur) performing five consecutive lifts. Measured elbow and knee trajectories preserved stage-dependent signatures and rapid transients for technique interpretation, while enabling expertise-level discrimination through differences in transient timing and trajectory regularity. Overall, the results support the proposed system as a practical, temporally consistent, and cost-effective wearable approach for multi-joint technique analysis in high-dynamic settings.
Comments11 pages, 11 figures
