The application of neural oscillators as trajectory generators to a wearable robotic suit

This paper applied neural oscillators as trajectory generators to a wearable robotic suit. The wearable robotic suit was designed for walking assist by supporting the whole lower limb, and it had four degrees-of-freedom (DOF). For assisting the whole lower limb, the coordination motion among the suit´s multiple joints becomes an important issue to concern. Also, the change of amplitude in a walking period should be considered. We investigated the phase differences among multiple joints and the change of amplitude of the knee flexion/extension motion in walking. In order to realize the complex phase differences among multiple joints, we proposed symmetrical and unsymmetrical inhibitory connections among neural oscillators. In order to make the amplitude changes more flexibly and naturally, we considered the measures of regulating amplitude of the knee flexion/extension motion. We investigated whether the proposed method was valid for realizing the natural trajectories of walking by conducting walking experiments. We verified that our proposal was valid for realization of the anti-phase relationship between the left and right hip joints and about 1/4πphase differences between the hip and knee joints on the ipsilateral side, and we verified that the amplitude regulation algorithm helped to realize the trajectories of natural walking.