Weenk Dirk, Roetenberg Daniel, van Beijnum Bert-Jan J F, Hermens Hermie J, Veltink Peter H
IEEE Trans Neural Syst Rehabil Eng. 2015 Sep;23(5):817-26. doi: 10.1109/TNSRE.2014.2357686. Epub 2014 Sep 15.
Relative foot position estimation is important for rehabilitation, sports training and functional diagnostics. In this paper an extended Kalman filter fusing ultrasound range estimates and inertial sensors is described. With this filter several gait parameters can be estimated ambulatory. Step lengths and stride widths from 54 walking trials of three healthy subjects were estimated and compared to an optical reference. Mean ( ± standard deviation) of absolute difference was 1.7 cm ( ±1.8 cm) and 1.2 cm ( ± 1.2 cm) for step length and stride width respectively. Walking with a turn and walking around in a square area were also investigated and resulted in mean absolute differences of 1.7 cm ( ±2.0 cm) and 1.5 cm ( ± 1.5 cm) for step lengths and stride widths. In addition to these relative positions, velocities, orientations and stance and swing times can also be estimated. We conclude that the presented system is low-cost and provides a complete description of footstep kinematics and timing.
相对足部位置估计对于康复、运动训练和功能诊断至关重要。本文描述了一种融合超声距离估计和惯性传感器的扩展卡尔曼滤波器。利用该滤波器，可以动态估计多个步态参数。对三名健康受试者的54次步行试验中的步长和步幅进行了估计，并与光学参考进行了比较。步长和步幅的绝对差的平均值（±标准差）分别为1.7厘米（±1.8厘米）和1.2厘米（±1.2厘米）。还研究了转弯行走和在方形区域内行走，步长和步幅的平均绝对差分别为1.7厘米（±2.0厘米）和1.5厘米（±1.5厘米）。除了这些相对位置外，还可以估计速度、方向以及站立和摆动时间。我们得出结论，所提出的系统成本低，并且能够完整描述脚步运动学和时间安排。
