Development of a closed-fitting-type walking assistance device on leg using torsion spring effect of a flexible shaft

A walking assistance device using a flexible shaft was developed. A combination of the flexible shaft with a worm gear was successfully adopted on this device to modify its appearance simple and its size compact. This device is controlled with a hybrid-control system both torque and angle at ankle and knee joints. In this system, the torsional spring constant of the flexible shaft is taken into account to the control power and the rotating angle of the motor. To expand the area of where an equipped parson can walk with the device, a self-contained system that controlled with SH-4 microcomputer and actuators, which consisted of motors and gears, were put in the small backpack, and Lithium-ion battery was utilized. Therefore, the equipped parson and patient can freely walk both in and out of doors environment.