Walking-assist principle analysis for a multi-legged system

As the aging problem becomes increasingly significant, robots are being widely applied as walking-assist devices for elders or patients suffering from walking disabilities. In this paper, a novel walking-assist multi-legged device that is fixed on the waist, with two machine legs independent from human legs, helps elders walk and climb stairs without any manipulation of the machine. In the proposed device, an inertial measurement unit (IMU) sensor is employed; the IMU contains a triaxial accelerometer, a triaxial gyro (angular rate sensor), and a triaxial magnetometer. The sensor is fixed on the waist of the elder in order to gauge the posture of the waist thereby preventing an emergency such as a fall. Further, based on the zero-moment point (ZMP), the stability of the device is analyzed to confirm the feasibility and effectiveness of this device.