Nonlinear guidance and control of leader-follower UAV formations

Kumbasar, Sarper
In this thesis work, two nonlinear guidance methods are proposed to control the autonomous formation flight: State Dependent Riccati Equation method and Lyapunov function method. Leader-Follower formation scheme is chosen and a pair of fighter aircrafts are used in simulations. One of them is chosen as the leader and it carries out the commanded maneuvers. Other aircraft is the follower and it follows the leader keeping the prescribed formation structure. Both aircraft models are nonlinear. In the inner loop, a nonlinear control algorithm, State Dependent Riccati Equation method is used to control the flight.


Chaotic period-doubling and OGY control for the forced Duffing equation
Akhmet, Marat (2012-04-01)
In this paper we consider the Duffing equation forced with a pulse function, whose moments of discontinuity depend on the initial data. Existence of the chaos through period-doubling cascade is proved, and the OGY control method is used to stabilize the periodic solutions. Appropriate simulations of the chaos and stabilized periodic solutions are presented.
Nonlinear Structural Coupling: Experimental Application
Kalaycioglu, Taner; Özgüven, Hasan Nevzat (2014-02-06)
In this work, the nonlinear structural modification/coupling technique proposed recently by the authors is applied to a test system in order to study the applicability of the method to real structures. The technique is based on calculating the frequency response functions of a modified system from those of the original system and the dynamic stiffness matrix of the nonlinear modifying part. The modification can also be in the form of coupling a nonlinear system to the original system. The test system used i...
Gurbuz, Merve; Tezer, Münevver (2019-01-01)
In this study, the radial basis function (RBF) approximation is applied for solving the unsteady fluid flow and magnetohydrodynamic (MHD) convection flow problems with the use of explicit Euler time discretization and relaxation parameters to accelerate the convergence. The stability analysis is also carried out in terms of the spectral radius of related RBF discretized coefficient matrices. The optimal choices of the time increment, relaxation parameters and physical problem parameters are found for achiev...
Nonlinear flutter calculations using finite elements in a direct Eulerian-Lagrangian formulation
Seber, Guclu; Bendiksen, Oddvar O. (American Institute of Aeronautics and Astronautics (AIAA), 2008-06-01)
A fully nonlinear aeroelastic formulation of the direct Eulerian-Lagrangian computational scheme is presented in which both structural and aerodynamic nonlinearities are treated without approximations. The method is direct in the sense that the calculations are done at the finite element level, both in the fluid and structural domains, and the fluid-structure system is time-marched as a single dynamic system using a multistage Runge-Kutta scheme. The exact nonlinear boundary condition at the fluid-structure...
Robust flight and landing autopilot /
Durmaz, Ozan; Leblebicioğlu, Mehmet Kemal; Department of Electrical and Electronics Engineering (2015)
In this thesis, a mathematical model of a small unmanned aircraft is implemented where the static and dynamic stability derivative coefficients are found by Digital DATCOM software. Several control methods are applied such as PID control, LQT, SMC. Two types of Sliding mode controllers are designed using different sliding surfaces. Linearized aircraft models which are trimmed at two different airspeeds are used to design controllers. A guidance block is implemented to guide aircraft with waypoints. Differen...
Citation Formats
S. Kumbasar, “Nonlinear guidance and control of leader-follower UAV formations,” M.S. - Master of Science, Middle East Technical University, 2015.