Estimation of center of mass trajectory of the body during 3D movements based on inertial sensor signals

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K12948
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Rehabilitation science/Welfare engineering
• Research Institution: Tohoku University
• Principal Investigator: Watanabe Takashi 東北大学, 医工学研究科, 教授 (90250696)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 身体重心 / 慣性センサ / 足部位置軌跡 / 姿勢ベクトル / 歩行

Outline of Final Research Achievements

This study aimed to developing a method to estimate movement trajectory of the center of mass (CoM) position of the body in 3D movements using inertial sensors. First, sensor attachment positions of the trunk and the thigh segments were examined, from which the upper part of the trunk and the lateral side of the thigh were determined to attach inertial sensors. Then, the calculation methods of the foot position and the segment vector of each part of the body were examined. Based on the results, the method of estimating the CoM position based on reconstructing the posture using the body link model was constructed using the foot position and the segment vectors. Finally, the constructed CoM trajectory estimation method was examined experimentally, and factors of the estimation error were discussed. The results showed that the anteroposterior and vertical components of the CoM position were useful, and the applicability to evaluation of movements of the CoM trajectory was suggested.

Free Research Field

生体医工学

Academic Significance and Societal Importance of the Research Achievements

本研究で開発を目指す体重心位置軌跡推定法により，荷重のような圧力センサ情報に類する指標が，慣性センサによる運動評価でも利用可能になると期待される．また，慣性センサを用いたシステムにより，これまで計測が困難であった運動機能障害者の運動の計測や医療施設等以外の実環境での計測が実施可能になる．これらの点が本研究の社会的意義である．一方，角度，ストライド長，歩行速度，歩行事象等，慣性センサ信号から算出可能な他の指標と組み合わせることで，光学式3次元動作解析システムに匹敵する解析機能を有する慣性センサ型3次元動作解析システムを実現するための基盤技術を構築する点に本研究の学術的意義がある．