基于改进零速修正算法的行步步长计算方法

Calculation Method of Walking Step Length Based on Improved Zero Speed Correction Algorithm

行走疲劳容易导致老年人摔倒,如果能够检测疲劳程度,就有可能降低老年人的摔倒风险。为此,以低成本、高精度实时检测为目标,设计了一种基于多传感器数据融合的步态采集系统。该系统可同步采集人体单脚的踝关节三维加速度数据、三维角速度数据、三维磁场数据以及脚底8个位置的压力数据,通过无线蓝牙方式发送到上位机进行数据分析和参数计算。针对传统零速修正算法的步长计算存在计算繁琐、精度不高的问题,通过脚底8个位置的压力数据划分步态时相,结合步态运动学分析,确定行人每一步的零速时刻来对陀螺仪测量值进行补偿以改进零速修正算法。实验结果表明,改进的步长计算算法较传统的步长计算算法降低了累积误差,可以高精度检测行人步态参数。

It is easy for the elderly to fall down because of their walking fatigue.Detection of fatigue can reduce the risk of falls in the elderly.A gait collection system based on multi-sensor data fusion is introduced to realize low-cost,high-precision and real-time detection of gait parameters of the human body while walking.The system can synchronously collect the three-dimensional acceleration data,three-dimensional angular velocity data,three-dimensional magnetic field data of ankle joint for single foot and plantar pressure data of eight positions.All the data mentioned above are sent to the upper computer through wireless Bluetooth for data analysis and parameter calculation.In order to solve the problems of complicated calculation and low precision in the calculation of the step length with traditional zero speed correction algorithm,gait phases are divided through the plantar pressure data of eight positions.Combined with gait kinematic analysis,the zero speed time of each step of the pedestrian is determined to compensate the gyroscope measurement values to improve the zero speed correction algorithm.The experimental results show that the improved step length calculation algorithm can reduce the cumulative error better than the traditional step length calculation algorithm and achieve high-precision detection of the gait parameters.