Football-specific validity of TRACAB's optical video tracking systems
Football-specific validity of TRACAB's optical video tracking systems
复制标题
DOI：
10.1371/journal.pone.0230179
复制
发表时间：
2020-03-10
期刊：
影响因子：
3.7
通讯作者：
Lames, Martin
中科院分区：
文献类型：
--
作者：
Linke, Daniel;Link, Daniel;Lames, Martin
本研究旨在验证和比较 TRACAB 设计的两种光学跟踪系统的足球专用测量精度。 “Gen4”系统由位于中场线两侧两个位置的两个多摄像机单元（立体声对）组成，而分布式“Gen5”系统则在球场两侧结合了两个立体声对以及球门区后面的两个单目系统。数据收集自 20 名男子足球运动员在专业足球场进行的两种不同训练（足球运动特定跑步课程和小场比赛）。为了评估系统的准确性，将测量值与参考系统（VICON 运动捕捉系统）同时记录的测量值进行比较。统计分析使用 RMSE 来表示运动学变量（位置、速度和加速度）以及每次运行与参考系统相比的性能指标（例如行驶距离、峰值速度）的百分比差异。明显没有跟踪玩家的帧被排除在外。与参考相比，Gen5 的位置测量精度 (0.08 m RMSE) 略高于 Gen4 (0.09 m RMSE)。瞬时速度（Gen4：0.09 m.s(-1) RMSE；Gen5：0.08 m.s(-1) RMSE）和加速度（Gen4：0.26 m.s(-2) RMSE；Gen5：0.21 m.s(-2) RMSE）测量的精度差异显着，但就效应大小而言也微不足道。对于总行驶距离，Gen4 (0.42 +/- 0.60%) 和 Gen5 (0.27 +/- 0.35%) 与参考相比仅显示出微小的偏差。 Gen4 在低速行驶距离类别中显示出中等差异（-19.41 +/- 13.24%），在高速行驶距离类别中显示出较小差异（8.94 +/- 9.49%）。 Gen4 和 Gen5 的峰值速度、加速度和减速度差异很小 (< 0.5%)。这些发现表明，在准确性方面，Gen5 的分布式相机架构比 Gen4 的单视图相机架构具有较小的优势。我们假设 Gen5 相对于 Gen4 的主要优势在于，当涉及到玩家的光学重叠时，跟踪的稳健性有所提高。由于与参考系统的差异非常小，只要正确跟踪球员，TRACAB 的跟踪系统都可以被视为在测试设置中进行足球特定表现分析的有效技术。
The present study aimed to validate and compare the football-specific measurement accuracy of two optical tracking systems engineered by TRACAB. The "Gen4" system consists of two multi-camera units (a stereo pair) in two locations either side of the halfway line, whereas the distributed "Gen5" system combines two stereo pairs on each side of the field as well as two monocular systems behind the goal areas. Data were collected from 20 male football players in two different exercises (a football sport-specific running course and small-sided games) in a professional football stadium. For evaluating the accuracy of the systems, measures were compared against simultaneously recorded measures of a reference system (VICON motion capture system). Statistical analysis uses RMSE for kinematic variables (position, speed and acceleration) and the difference in percentages for performance indicators (e.g. distance covered, peak speed) per run compared to the reference system. Frames in which players were obviously not tracked were excluded. Gen5 had marginally better accuracy (0.08 m RMSE) for position measurements than Gen4 (0.09 m RMSE) compared to the reference. Accuracy difference in instantaneous speed (Gen4: 0.09 m.s(-1) RMSE; Gen5: 0.08 m.s(-1) RMSE) and acceleration (Gen4: 0.26 m.s(-2) RMSE; Gen5: 0.21 m.s(-2) RMSE) measurements were significant, but also trivial in terms of the effect size. For total distance travelled, both Gen4 (0.42 +/- 0.60%) and Gen5 (0.27 +/- 0.35%) showed only trivial deviations compared to the reference. Gen4 showed moderate differences in the low-speed distance travelled category (-19.41 +/- 13.24%) and small differences in the high-speed distance travelled category (8.94 +/- 9.49%). Differences in peak speed, acceleration and deceleration were trivial (< 0.5%) for both Gen4 and Gen5. These findings suggest that Gen5's distributed camera architecture has minor benefits over Gen4's single-view camera architecture in terms of accuracy. We assume that the main benefit of the Gen5 towards Gen4 lies in increased robustness of the tracking when it comes to optical overlapping of players. Since differences towards the reference system were very low, both TRACAB's tracking systems can be considered as valid technologies for football-specific performance analyses in the settings tested as long as players are tracked correctly.