A Non-Delay Optimal Disturbance Rejection Control Approach for Nonlinear sysTems with External distUrbances and Control Delay

A kind of non-delay optimal control problem for nonlinear time-delay systems affected by external disturbance with quadratic performance index is considered. Through the Artstein transformation, the nonlinear time-delay system is translated into simple nonlinear system without delay. Then the finite horizon and infinite horizon quadratic performance index are discussed, we get approximate optimal control law by solving a Riccati matrix equation and two Stein matrix equations using successive approximation method. A simulation example shows that the approximate approach is effective and robust with respect to exogenous persistent disturbances.