numerical method for time-invariant delay optimal control problems

This paper, the adomian decomposition method and variational iteration method are applied to obtain suboptimal control for linear time-varying systems with multiple state and control delays and with quadratic cost functional. the optimal controlb law obtained consists of an accurate linear feedback term and a nonlinear compensation term which is the limit of an adjoint vector sequence. the feedback term is determined by solving riccati matrix differential equation. through the finite iterations of algorithm, a suboptimal control law is obtained for the nonlinear optimal control problem.