Discrete-time periodic adaptive control for parametric systems with non-sector nonlinearities

摘要

In this paper, a periodic adaptive control approach is proposed for a class of discrete-time parametric systems with non-sector nonlinearities. The proposed periodic adaptive control law is characterized by either one-period delayed parametric updating or two-period delayed parametric updating when input gain contains periodic unknowns. Logarithmic-type discrete Lyapunov function is employed to handle the difficulties caused by the uncertainties that do not satisfy the linear growth condition. Some extensions to nonlinear systems with multiple unknown parameters and time-varying input gain, tracking tasks, as well as higher-order systems in canonical form, are also discussed.