Measuring orientation of human body segments using miniature gyroscopes and accelerometers
Measuring orientation of human body segments using miniature gyroscopes and accelerometers
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DOI：
10.1007/bf02345966
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发表时间：
2005-03-01
影响因子：
3.2
通讯作者：
Veltink, PH
中科院分区：
文献类型：
--
作者：
Luinge, HJ;Veltink, PH
在医学领域，需要小型的动态传感器系统来测量身体各部分的运动学。当身体运动时，当前的身体方向动态测量方法精度有限。本文的目的是开发和验证一种使用惯性测量单元（IMU）精确测量人体部分方向的方法。IMU包含三个单轴加速度计和三个单轴微机械陀螺仪，组装在一个尺寸为20 x 20 x 30 mm的矩形盒子中。该算法对陀螺仪测得的三维角速度进行数学积分得到的姿态估计进行连续修正。利用三维加速度计的信号连续获得的倾角估计值进行校正。这减少了由角速度信号误差引起的积分漂移。此外，陀螺仪的偏移量被不断地重新校准。该方法是利用卡尔曼滤波器实现的，该滤波器考虑了所涉及信号的频谱以及陀螺仪偏移量的波动。该方法对骨盆、躯干和前臂的运动进行了测试。虽然全球垂直方向的积分漂移问题以0.5°s（-1）的数量级不断增加，但倾角估计的RMS精度在3°以内。试验表明，陀螺仪的偏移量可以连续估计。使用1 rad s（-1）的初始偏移误差，2分钟后的偏移误差大约是原始偏移误差的5%。利用所描述的卡尔曼滤波器，可以实现精确、鲁棒的动态运动记录系统。
In the medical field, there is a need for small ambulatory sensor systems for measuring the kinematics of body segments. Current methods for ambulatory measurement of body orientation have limited accuracy when the body moves. The aim of the paper was to develop and validate a method for accurate measurement of the orientation of human body segments using an inertial measurement unit (IMU). An IMU containing three single-axis accelerometers and three single-axis micromachined gyroscopes was assembled in a rectangular box, sized 20 x 20 x 30 mm. The presented orientation estimation algorithm continuously corrected orientation estimates obtained by mathematical integration of the 3D angular velocity measured using the gyroscopes. The correction was performed using an inclination estimate continuously obtained using the signal of the 3D accelerometer. This reduces the integration drift that originates from errors in the angular velocity signal. In addition, the gyroscope offset was continuously recalibrated. The method was realised using a Kalman filter that took into account the spectra of the signals involved as well as a fluctuating gyroscope offset. The method was tested for movements of the pelvis, trunk and forearm. Although the problem of integration drift around the global vertical continuously increased in the order of 0.5 degrees s(-1), the inclination estimate was accurate within 3 degrees RMS. It was shown that the gyroscope offset could be estimated continuously during a trial. Using an initial offset error of 1 rad s(-1), after 2 min the offset error was roughly 5% of the original offset error. Using the Kalman filter described, an accurate and robust system for ambulatory motion recording can be realised.