H2 and H∞ optimal control of coordinated fingers movement

Abstract

In the rich repertoire of biomechanical systems bond graph is a proper choice for the modeling, analysis and simulation of biomechanical models. In this paper, we present the study of optimal robust control of a biomechanical model of reflexive movement of human ring finger when the little finger is bent. This is a 12th order model for movement simulation of two fingers. We developed H2/H∞ robust feedback controllers for the model in order to synthesize by combining a full information controller with an estimator to achieve stabilizing results. We later included parametric uncertainties of the model as modeling noise and exogenous inputs of the model. Furthermore, we tuned the controller performance to minimize the effects of the disturbances and the impact of the measurement noise and modeling errors. We simulated the model in MATLAB/Simulink for study of stability analysis and performance comparison. Our simulation results demonstrate the applicability of the model towards active prosthetic, and help to understand central nervous system in physiologically coordinated movement and constraint on motor functions.