AIRPLANE FLIGHT DYNAMICS MODELING AS DEMANDED BY THE CONTROL SYSTEM DESIGN

Dr Predrag Stojaković

Prof. dr Boško Rašuo

Abstract: The basis for the airplane flight control system design presents the model of its dynamics, consisting of the set of interacting dynamic subsystems. Beside the model of the airplane dynamics itself, the successful design of the airplane flight control system requires, especially in the final pre-flight simulation testing, the use of the models of the dynamics of the set of the subsystems that are acting on the airplane, as well as the models of the dynamics of the subsystems that are the elements of the flight control system. The core of the successful flight control system design basis is the model of the airplane dynamics, the dynamic being one of the rigid body moving through fluid. Model application in the flight control system design demands that the model of the aerodynamic forces and moments is obtained within the control volume through the Taylor series development upon the set independent variables. This form of the model enables the single software procedure for the calculation of the aerodynamic forces and moments to be used for the integrated application of the inverse and direct solution of the airplane flight dynamics and simple procedures of the airplane dynamics linearization. Software application of this combination of procedures is the most efficient one in the initial phases of the airplane control laws design.

As stated, within the model of the dynamics of the airplane as the controlled object, the model of the propulsive group dynamics and the model of the armament action must be integrated, as well as the variations of the airplane body inertial properties. For the flight control system design the model of the sensor induction of these mechanical variables that are required by the flight control laws realization is significant. The models of the flight control subsystem elements, like internal sensor dynamics, servoactuator dynamics and flight control computer model, are not the subject of this monograph

Key words: airplane, airplane flight, flight dynamics, mathematical model,
airplane control, control system, system design, flight simulation.