慣性センサを活用した屋外歩行におけるリアルタイム歩幅・歩調推定システム

（歩行効率の評価への適用）

抄録

It is considered that energy consumption can be reduced by selecting appropriate stride length and cadence during walking. In order to verify the assumption in outdoor walking, it is required to estimate the stride length accurately in real-time. The purpose of this study is to build a system to estimate the stride length in real time using inertia measurement units (IMU) fixed on the shank. We estimate the ankle acceleration from the IMU and integrate it based on the Zero Velocity Update (ZUPT) concept. The accuracy of the estimated stride length was verified by comparing with the result from the three-dimensional motion analysis system. As a result, the maximum standard deviation of the estimation error was 41.5 mm. We calculated the stride length by averaging 10 steps to keep the estimation error to around 10 mm. We conducted overground walking tests using the developed system. In this test, the walking speed was kept constant at the individual preferred speed, and the stride length and cadence were designed in five patterns. The test measured the heart rate as an index of energy consumption. Due to the developed system, we achieved overground walking with a stride length variation of less than ±5cm. The heart rate tended to be the lowest when the stride length and cadence were close to the free walking.