Abstract
This paper discusses a development of an exoskeleton-type walking assist machine having essentially minimum number of joints in order to guarantee the intrinsic safety, simple and inexpensive structure, and can be divided into two pieces so that a part of the apparatus can be detached, when that part becomes unnecessary due to a recovery of body function. Since the obtained mechanism was designed to achieve target human gaits obtained by a number of motion capture experiments, including changings of step lengths and turnings of walking directions. In the determination of the mechanism composition, at first, a most practical composition was chosen among four candidates that were found by taking different selections of possible attachment locations between the device and a human's lower limb into account. Subsequently, the number of joints of the determined composition was synthesized by using only revolute joints so that the device could establish the required DOF for generating the motion of human gait. After that, dimensions of the obtained mechanism were determined through an optimization process considering a minimization of required driving torque which was calculated by a static analysis of the mechanism.
