In this paper, we develop an integrated markerless gait tracking system with three Kinect v2 sensors. A geometric principle-based trilateration method is proposed for optimizing the accuracy of the measured gait data. To tackle the data synchronization problem among the Kinect clients and the server, a synchronization mechanism based on NTP (Network Time Protocol) is designed for synchronizing the server and Kinect clients' clocks. Furthermore, a time schedule is designed for timing each Kinect client's data transmission. In the experiment, participants are asked to perform a 60 s walk while the proposed tracking system obtains the participant's gait data. Six joints (including left hip, right hip, left knee, right knee, left ankle and right ankle) of the participants are tracked where the obtained gait data are described as 6000 {movements} of joint positions (1000 {movements} for each joint). The results show that the trilateration tracking result by the three Kinect sensors has a much higher accuracy compared with the accuracy measured by a single Kinect sensor. Within a randomly sampled time period (67.726 s in the experiment), 98.37% of the frames generated by the gait tracking system have timing errors less than 1 ms, which is much better than the default NTP service embedded in the Windows 8.1 operating system. The accuracy of the proposed system is quantitatively evaluated and verified by a comparison with a commercial medical system (Delsys Trigno Smart Sensor System).
翻译:在本文中, 我们开发了一个集成的无标记行进跟踪系统, 包括三个 Kinect v2 传感器。 为了优化测量的行进数据的准确性, 提议了一个基于几何原则的三角化方法 。 要解决Kinect 客户和服务器的数据同步问题, 一个基于 NTP (Network Time Protology) 的同步机制, 用于同步服务器和 Kinect 客户的时钟 。 此外, 为每个 Kinect 客户的数据传输时间设计了一个时间表 。 在实验中, 请参与者在拟议的跟踪系统获得参与者的行走数据时, 行走60 。 在随机抽样的时段( 包括左臀、 右臀、 左膝、 右膝、 左脚和右脚踝) 中, 六个参与者的连接点( 包括左臀、 左膝、 左脚和右踝) 。 在所获取的行曲调数据被描述为联合位置 ( 100 {movementment ) ( NTP ) 。 结果显示, 3个 Kinectal 跟踪结果比一个单一 Kinect 传感器的准确性传感器的准确性 。 在随机系统中, NTP 系统上, 的精确度系统中, 有比98.