A multilayer neural-network (NN) controller is designed to deliver a desire
d tracking performance for the control of a class of unknown nonlinear syst
ems in discrete time where the system nonlinearities do not satisfy a match
ing condition. Using the Lyapunov approach, the uniform ultimate boundednes
s (UUB) of the tracking error and the NN weight estimates are shown by usin
g a novel weight updates. Further, a rigorous procedure is provided from th
is analysis to select the NN controller parameters. The resulting structure
consists of several NN function approximation inner loops and an outer pro
portional derivative (PD) tracking loop. Simulation results are then carrie
d out to justify the theoretical conclusions. The net result is the design
and development of an NN controller for strict-feedback class of nonlinear
discrete-time systems.