Higher-order tracking properties of nonlinear adaptive control systems

While the asymptotic output tracking property has been proven for many nonlinear adaptive control systems, their higher-order output tracking property has not been reported. In this paper, the higher-order derivative convergence of the output tracking error e(t) is studied for nonlinear adaptive control systems using the feedback linearization design. It is proven that not only each error component e(j)(t) from e(t) = [e(1)(t), e(2)(t), ..., e(m)(t)](T) converges to zero asymptotically but also its up to kth-order time-derivative e(j)((k))(t) converges to zero, for k = 1, 2, ..., rho(j), where , = rho(j), j = 1, 2, ..., m, are the control relative degrees of the nonlinear system with m inputs. (C) 2020 Elsevier B.V. All rights reserved.