Design and control of an active-caster electric walker with a walk sensing system (Smart Walker)

摘要

In this paper, a new type of an electric walker driven by active-casters, Smart Walker, is proposed. Smart Walker has three wheels, two drive wheels on the front and one passive wheel on the rear. The front drive wheels are active-casters which can provide active traction force in any direction to create translation motion in back and forth direction and/or turn motion of the walker. Smart Walker provides a unique interface with a walk sensing system for control its motion by the legs for elderly persons or rehabilitation purpose. A user of Smart Walker just sits on the chair like a bicycle manner and moves his/her legs in a normal walking pattern. A laser range sensor on the walker frame detects feet motions for measuring a direction and a velocity of the user's left and right feet independently. A walk sensing system estimates the users will by tracking a swing leg motion which includes the direction and the velocity information to go. By using the estimation results, the active-casters on the front side of Smart Walker are driven for realizing the power assistance of a walking task. Therefore, Smart Walker can be used for elderly persons to enhance not only their activities, but also to prevent of losing their walking abilities. Furthermore, it would be possible to apply Smart Walker to rehabilitation purpose to help and recover patients walking capabilities.