Digital adaptive control of continuous-time nonlinear systems

Abstract

The problem of digital adaptive control for continuous-time nonlinear systems including unknown parameters is considered. Most of existing works propose design methods to get discrete-time controllers based on discrete-time models. The problem is that the involved models cannot be considered as perfect discrete-time representations of continuous-time systems because no discretization error is accounted for. In this paper, the control problem of interest is dealt with using a three-step approach. First, an accurate discrete-time model, which accounts for the discretization error, is established for the continuous-time system. Then, using the delta-operator, a (discrete-time) controller that robustly stabilizes the (discrete-time) model is developed. Finally, a continuous-time controller is built-up, based on the above discrete-time controller, using a ZOH signal reconstruction.