Least squares state estimator based sliding mode control of a very lightweight single-link flexible robot arm

A sliding mode controller and an algebraic state estimator are applied to an uncertain single-link flexible robot arm. This paper exploits and explores the synergy of these two techniques in the context of the regulator problem. The following uncertain parameters are considered in this work: mass, the viscous friction coefficient and the Coulomb friction coefficient. In consequence, the corresponding uncertain model has both matched and unmatched uncertainties. The sliding mode control design methodology applied is the so-called unit vector approach. The algebraic state estimator is based on a polynomial of degree n to estimate the unmeasured states. Computer simulations were carried out to validate the suitability of the proposed approach.