An approach to walking assist control by a multi-legged system in human gait motion

Lacking in adequate care for the elders, especially those who are walking with inconvenience is becoming a growing problem for the aging society. The elders who walk with inconvenience, once they fall down, it is very dangerous. It is also necessary for the elders to exercise walking in order to keep normal social life. Many kinds of walking aids have been developed, but most of them are fail to avoid the elders' falling down problem which is an important issue for aged care. So far, there are few researches focusing on the walking cooperation between human and legged robot. The Inertial Measurement Unit (IMU) contains a triaxial (3-D) accelerometer, a triaxial gyro (angular rate sensor) and a triaxial magnetometer, and consequently in this paper, one IMU sensor fixed near the elder's waist to measure the posture is proposed in case that the elders fall down. Two short encoder links tied on human two legs can measure the rotate angles of thign and supply the command to the proposed device. To make human feel comfortable under various situation, impedance control is also employed in this system. The performance of the approach proposed in this paper has been examined by experiments.