ADAPTIVE-CONTROL OF A CLASS OF NONLINEAR DISCRETE-TIME-SYSTEMS

We consider adaptive control via state feedback for a class of feedbac k linearizable discrete-time systems. To parallel the development in a daptive nonlinear continuous-time control, we employ a systematic proc edure to design the controllers and the update laws for the so-called parametric-strict-feedback form and the parametric-pure-feedback form. The geometric conditions that characterize this class of systems are given. Depending on the growth conditions of the nonlinearities, globa l boundedness and convergence are achieved with various update laws. W e also develop adaptive indirect schemes with an observer-based identi fier for the parametric-strict-feedback form. As a result, the drawbac k of overparametrization in direct schemes can be removed.