Song Sa-kwang, Jang Jaewon, Park Soo-Jun
138 Gajeongno, Yuseong-gu, Daejeon, 305-700, South Korea.
Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:6175-8. doi: 10.1109/IEMBS.2009.5334503.
We propose a dynamic activity classification system with tri-axial accelerometer sensor using adaptation of user's postural orientation. In general, the sensor module is worn at a fixed position such as waist, head, wrist, thigh, and so on. However, in reality, the tilt of the attached sensor could be changed from time to time in actions such as sitting down, standing up, lying, walking or running. Moreover, most of the users want to wear the sensor at their own favorite positions instead of a recommended position. In these cases, the activity detection methods based on fixed tilt value may produce serious problem in their performance. Therefore, we propose a user adapted activity classification method which enables users to freely wear the sensor everywhere on their torso. In order to decide tilt values corresponding user's postural orientation, we focused on tilt-free activities such as walking and running. While walking, the algorithm tries to modify the predefined reference tilt values for the three axes, X, Y and Z. From an experiment, we have achieved 88% of the activity classification accuracy even though the tilt angle is changed while wearing sensors.
我们提出了一种利用三轴加速度计传感器并结合用户姿势方向自适应的动态活动分类系统。一般来说，传感器模块佩戴在诸如腰部、头部、手腕、大腿等固定位置。然而，在现实中，在坐下、站起、躺卧、行走或跑步等动作中，附着传感器的倾斜度可能会随时改变。此外，大多数用户希望将传感器佩戴在自己喜欢的位置，而不是推荐的位置。在这些情况下，基于固定倾斜值的活动检测方法在性能上可能会产生严重问题。因此，我们提出了一种用户自适应活动分类方法，该方法能让用户在躯干上的任何位置自由佩戴传感器。为了确定与用户姿势方向对应的倾斜值，我们重点关注了诸如行走和跑步等无倾斜活动。在行走时，该算法会尝试修改预先定义的X、Y和Z三个轴的参考倾斜值。通过实验，即使在佩戴传感器时倾斜角度发生变化，我们也实现了88%的活动分类准确率。
