Nonlinear optimal control of an aerial vehicle with consideration of nonlinear Modeling of thruster engine

This article deals with dynamic modeling and nonlinear optimal control of an aerial vehicle taken into account nonlinear modeling of its thruster engine. To do this, nonlinear flight dynamic equations of the aerial vehicle are derived considering nonlinear equations of the thruster engine. A relation between the thrusting force and the fuel consumption of the air-breathing engine is stated and coupled with the nonlinear dynamic equations of the vehicle. Presenting the formulation of the state-dependent nonlinear optimal control, the nonlinear dynamic relations of the aerial vehicle are considered as constraint equations of the optimal control and a cost function including state and input variables is defined. Then, the Hamiltonian function of the optimal control problem is formed and optimality equations obtained. By numerical solving of the problem, various parameters like as the path angle, uncertainties, attack angle and weighting coefficients of the optimal control are considered and several simulations are presented. The results show that increasing the attack angle leads to increasing of the control time and effort of the system. Also, changing the weighting coefficients lead to various optimal paths as increasing the input weighting coefficient decreases the fuel consumption. It is seen by changing the uncertainty parameter of the model, transient response is changed but finally the optimal control method is able to track the desired path. Furthermore, by changing initial conditions and parameters, the nonlinear optimal control of the system is effectively performed which indicates the priority of the proposed method