Optimal control for a class of nonlinear system with controller constraints based on finite-approximation-errors ADP algorithm

In this paper, a finite-approximation-errors iterative adaptive dynamic programming (ADP) algorithm is proposed to solve optimal control problems for nonlinear systems with controller constraints. Considering the controller constraints, a nonquadratic performance index function is introduced. The finite-approximation-errors iterative ADP algorithm is used to obtain the iterative control law which makes the iterative performance index function reach the optimum. It shows that the iterative performance index functions can converge to a finite neighborhood of the greatest lower bound of all performance index functions. Finally, a simulation example is given to illustrate the performance of the proposed method.