Book-Chapter-Field-AU.pdf

Abstract

The first cuntional load-carrying and energetically autonomous exoskeleton was demonstrated at U.C. Berkeley, walking at the average speed of 1/3 m/s while carrying a 34 kg (75 lb) payload. Four fundamental technologies associated with the Berkeley Lower Extremity Exoskeletong (BLEEX) were tackled during the course of this project. These four core technologies include: the design of the exoskeleton architecture, control schemes, a body local area network (bLAN) to host the control algorithm and an on-board power unit to power the actuators, sensors and the copmuters. This article gives an overview of one of hte control schemes. The analysishere is an extension of hte calssical definiation of hte sensitivity function of a system: the ability of a system to reject disturbances or the measure of system robustness. The conrol algorithm developed here increases the clsoed loop system sensitivity to its wearer's forces and torques wihtout any measurement from the wearer (such as force, position, or elctromyogram signal). The control method has little robustness to parameter variations and therefore requires a relatviely good dynamic model of the system.