Robust and adaptive control of Euler-Lagrange systems with an attractor independent of uncertainties

Tracking control for Euler - Lagrange (EL) systems is a very important problem. Current control methods have achieved a lot of success in solving the problem with the accurate and stable kinetic model as well as no disturbance. Facts have shown that there were many EL systems working in unstable environment, or carrying different masses, which is conducive to significant modeling errors, disturbances or uncertain constants. Therefore, it is necessary to design adaptive controller, robust controller, and disturbance attenuating controller or even associate all of them to meet actual requirements. This paper presents a method to solve these both three problems with ability of maintaining tracking error in an arbitrary sufficiently small neighborhood of the origin, which is independent on the value of uncertain constants.