Prediction of the dynamic characteristics and control of aircraft in prescribed trajectory flight

A unified and general approach to modeling and simulation of aircraft prescribed trajectory fight is presented in the paper. The program of motion is composed of a specified trajectory in space (two constraints on the aircraft position), a required fuselage attitude with respect to the trajectory, and optionally, a specified flight velocity. For an aircraft traditionally controlled by aileron, elevator and rudder deflections and thrust changes, a tangent realization of the trajectory constraints arises, which yields two additional constraints on the fuselage attitude (which thus becomes fully specified). The governing equations of the programmed motion are developed in the form of differential-algebraic equations, and a method of solving the equations is proposed. The solution consists of variations of the aircraft state variables and the required control that ensures realization of the prescribed motion program. This gives a unique opportunity to study simulated control strategies and evaluate feasibility of modeled aircraft missions. Some results of numerical simulations are reported.