Adaptive tracking control of Euler-Lagrange systems with bounded controls

Abstract

"We solve the simultaneous closed?loop identification and tracking?control problems for fully actuated Euler-Lagrange systems under input constraints. We use a nonlinear adaptive controller reminiscent of computed?torque?type controllers in which linear correction terms are saturated in order to comply with the imposed bounds on the control inputs. Adaptation, reminiscent of gradient methods, is used also with saturation. With respect to related literature, our contribution consists in establishing uniform global asymptotic stability. Therefore, our control scheme ensures robustness with respect to bounded perturbations and uniform convergence of the estimation errors for any initial conditions."