Modified Nonlinear Quadratic Gaussian Control with Guaranteed Stability Margin

In this paper the robustness of Beaman’s Nonlinear Quadratic Gaussian control method is discussed and then Hedrick’s Nonlinear Quadratic Gaussian control (NQG) synthesis is introduced. Based on these methods, a modified NQG control is presented. This controller possesses guaranteed stability phase and gain margins. The numerical algorithm of this method is described. An illustrative example of engine throttle control is included to demonstrate the application of the proposed method to nonlinear systems.