Saito Ayuko, Sai Natsuki, Kurotaki Kazutoshi, Komatsu Akira, Morichi Shinichiro, Kizawa Satoru
Department of Mechanical Science and Engineering, Kogakuin University, 2665-1 Nakanomachi, Hachioji 192-0015, Tokyo, Japan.
Graduate School of Engineering, Kogakuin University, 2665-1 Nakanomachi, Hachioji 192-0015, Tokyo, Japan.
Sensors (Basel). 2025 Jul 21;25(14):4527. doi: 10.3390/s25144527.
Gait evaluation approaches using small, lightweight inertial sensors have recently been developed, offering improvements in terms of both portability and usability. However, accelerometer outputs include both the acceleration that is generated by human motion and gravitational acceleration, which changes along with the posture of the body part to which the sensor is attached. This study presents a gait analysis method that uses the gravitational, centrifugal, tangential, and translational accelerations obtained from sensors attached to the lower legs. In this method, each sensor pose is sequentially estimated using sensor fusion to combine data obtained from a three-axis gyroscope, a three-axis accelerometer, and a three-axis magnetometer. The estimated sensor pose is then used to calculate the gravitational acceleration that is included in each axis of the sensor coordinate system. The centrifugal and tangential accelerations are determined from the gyroscope output. The translational acceleration is then obtained by subtracting the centrifugal, tangential, and gravitational accelerations from the accelerometer output. As a result, the acceleration components contained in the outputs of the accelerometers attached to the lower legs are provided. As only the acceleration components caused by walking motion are captured, thus reflecting their characteristics, it is expected that the developed method can be used for gait evaluation.
近年来，已开发出使用小型、轻型惯性传感器的步态评估方法，在便携性和可用性方面均有改进。然而，加速度计的输出既包括人体运动产生的加速度，也包括重力加速度，而重力加速度会随着传感器所附着身体部位的姿势而变化。本研究提出了一种步态分析方法，该方法使用从附着在小腿上的传感器获得的重力、离心、切向和平动加速度。在该方法中，利用传感器融合依次估计每个传感器的姿态，以合并从三轴陀螺仪、三轴加速度计和三轴磁力计获得的数据。然后，使用估计出的传感器姿态来计算传感器坐标系各轴中包含的重力加速度。根据陀螺仪输出确定离心加速度和切向加速度。然后，通过从加速度计输出中减去离心加速度、切向加速度和重力加速度来获得平动加速度。结果，得到了附着在小腿上的加速度计输出中包含的加速度分量。由于仅捕捉到由步行运动引起的加速度分量，从而反映了它们的特征，因此预计所开发的方法可用于步态评估。
