  In this paper, near optimal tracking of a class of nonlinear systems is
addressed. Adaptive (approximate) dynamic programming approach is used to
calculate the optimal control in closed form. ADP (Adaptive (approximate)
dynamic programming) has been widely used to resolve optimal regulation and
tracking problems of nonlinear control systems. Despite advances in the so
called supervised and unsupervised ADP techniques for optimal tracking, they
have a main draw back. That is, the optimal controller needs to be recalculated
for every particular reference trajectory. The main goal of this work is to
address this issue for a class of nonlinear systems. Finally, this approach is
applied on a Delta robot and the performance of the method is analyzed
experimentally.
