Robust control of an actuated orthosis for lower limb movement restoration

Abstract

The present chapter deals with the development of two rehabilitation approaches of the lower limb by means of the knee joint exoskeleton EICOSI. The model of the exoskeleton is presented as well as a modified Hill-type muscular model of the wearer’s lower limb. The parameters of the shank-foot-exoskeleton and the muscles are identified based on a least square optimization algorithm. Two control techniques are proposed: the first one ensures the passive rehabilitation of the lower limb by means of bounded control laws and the second ensures the assistance-as-need of the wearer based on the human intention estimated by means of EMG electrodes fixed at some particular muscles. Experimental tests are performed on healthy subjects and show the efficiency of the proposed strategies.