Nonlinear H^|^infin; Control via Measurement Feedback in Robotic Systems

Abstract

In this paper, we study the nonlinear H∞ control problem in robotic systems. Especially we consider the measurement feedback problem when velocitysignals are not available. So far, the solution of the nonlinear H∞ state feedback problem in robotic systems has been proposed by B.S. Chen in 1994. We extend Chen's state feedback solution to the measurement feedback problem using only position signals. In this process, using Isidori's differential-game-like approach, we derive Chen's state feedback solution more easily and make the extension to the measurement feedback problem rather simple. And in the numerical simulation of 2-link manipulator system, we make sure that if disturbance attenuation level ‘γ’ is set appropriately small, the performance of our measurement controller is as equal as that of Chen's state feedback controller.