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.


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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...
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By using a Picone type formula in comparison with oscillatory unforced half-linear equations, we derive new oscillation criteria for second order forced super-half-linear impulsive differential equations having fixed moments of impulse actions. In the superlinear case, the effect of a damping term is also considered.
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Akbaş, Meral; Rebholz, L. G.; Zerfas, C. (Springer Science and Business Media LLC, 2018-03-01)
We study a velocity-vorticity scheme for the 2D incompressible Navier-Stokes equations, which is based on a formulation that couples the rotation form of the momentum equation with the vorticity equation, and a temporal discretization that stably decouples the system at each time step and allows for simultaneous solving of the vorticity equation and velocity-pressure system (thus if special care is taken in its implementation, the method can have no extra cost compared to common velocity-pressure schemes). ...
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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...
Unpredictable Oscillations for Hopfield-Type Neural Networks with Delayed and Advanced Arguments
Akhmet, Marat; Tleubergenova, Madina; Nugayeva, Zakhira (2021-03-01)
This is the first time that the method for the investigation of unpredictable solutions of differential equations has been extended to unpredictable oscillations of neural networks with a generalized piecewise constant argument, which is delayed and advanced. The existence and exponential stability of the unique unpredictable oscillation are proven. According to the theory, the presence of unpredictable oscillations is strong evidence for Poincare chaos. Consequently, the paper is a contribution to chaos ap...
Citation Formats
S. Kumbasar, “Nonlinear guidance and control of leader-follower UAV formations,” M.S. - Master of Science, Middle East Technical University, 2015.