A nonlinear high-gain observer for n-link robot manipulator which has measurement noise in a feedback control framework

Abstract

This paper presents the design of an output feedback controller (OFBC) for an n-link robot manipulator. This is achieved by using non-linear high gain observer. As measurement noise poses a great difficulty while estimating the system states, as the gain of the observer increases the measurement noise significantly amplified, causing higher steady state error. A non-linear high gain observer is proposed to overcome this problem. Non-linear high gain observer has an advantage over other non-linear state estimating techniques. The estimation of states is achieved with great accuracy and in a very small time. A comparison of linear and non linear high gain observer is also included to show the effectiveness of the proposed scheme.