Department of Biomedical Signals Systems, Technical Medical Centre, University of Twente, 7500 AE Enschede, The Netherlands.
School of Marine Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China.
Sensors (Basel). 2020 Jul 19;20(14):4008. doi: 10.3390/s20144008.
Relative orientation estimation between the hand and its fingers is important in many applications, such as virtual reality (VR), augmented reality (AR) and rehabilitation. It is still quite a big challenge to do the estimation by only exploiting inertial measurement units (IMUs) because of the integration drift that occurs in most approaches. When the hand is functionally used, there are many instances in which hand and finger tips move together, experiencing almost the same angular velocities, and in some of these cases, almost the same accelerations are measured in different 3D coordinate systems. Therefore, we hypothesize that relative orientations between the hand and the finger tips can be adequately estimated using 3D IMUs during such designated events (DEs) and in between these events. We fused this extra information from the DEs and IMU data with an extended Kalman filter (EKF). Our results show that errors in relative orientation can be smaller than five degrees if DEs are constantly present and the linear and angular movements of the whole hand are adequately rich. When the DEs are partially available in a functional water-drinking task, the orientation error is smaller than 10 degrees.
手与其手指之间的相对姿态估计在虚拟现实（VR）、增强现实（AR）和康复等许多应用中非常重要。由于大多数方法中都会出现积分漂移，因此仅利用惯性测量单元（IMU）进行估计仍然是一个很大的挑战。当手被功能性使用时，有很多情况下手和指尖一起移动，经历几乎相同的角速度，并且在这些情况下中的一些情况下，在不同的 3D 坐标系中测量到几乎相同的加速度。因此，我们假设在这种指定事件（DE）期间和这些事件之间，可以使用 3D IMU 充分估计手和指尖之间的相对姿态。我们将来自 DE 的额外信息与扩展卡尔曼滤波器（EKF）融合。我们的结果表明，如果 DE 始终存在并且整个手的线性和角运动足够丰富，则相对姿态的误差可以小于五度。在手功能饮水任务中，当 DE 部分可用时，定向误差小于 10 度。
