Ground Collision-Free Motion for Gait Rehabilitation

Abstract

We present an alternative method of modification of a given gait motion to prevent possible collision between foot and ground during gait training on rehabilitation robots with an exo-skeleton, such as COWALK [2]. Recently, Chun et al. [1] present Gaussian Process-based gait motion generation framework for gait rehabilitation. However, the method does not guarantee a motion free from ground-collision. Sometimes, even a collision-free motion in numerical simulation results in grazing or collision of swinging toes against ground or treadmill due to the error in the kinematic model of lower body. In this paper, we describe a method to prevent the collision by giving user defined clearance to lift the foot. Also, the amount of modification increases from and decreases to zero gradually, so that the resulting motion changes smoothly.