Varying mass missile dynamics, guidance & control

Günbatar, Yakup
The focus of this study is to be able to control the air-to-surface missile throughout the entire flight, with emphasis on the propulsion phase to increase the impact range of the missile. A major difficulty in controlling the missile during the propulsion phase is the important change in mass of the missile. This results in sliding the center of gravity (cg) point and changing inertias. Moreover, aerodynamic coefficients and stability derivatives are not assumed to be constant at predetermined ranges; conversely, they depend on Mach number, angle of attack, and side slip angle. Consequently, as the change of missile mass, cg point, inertia terms, and stability and aerodynamic coefficients come together apart from flight operation stages, a great number of points need to be taken into account when designing the controller. This makes controlling the missile all the more complicated. In this thesis, first the equations of motion are derived, in which, mass of the missile is not assumed constant. Thus, not only the variation of mass but also the variation of inertias is incorporated in the equations of motion. From the derived equations of motion, a nonlinear inverse dynamics controller that can achieve desired guidance for a conceptually developed air-to-surface missile has been designed, tested and verified for a modeled missile with six degrees of freedom. For brevity of the study, conceptual design and aerodynamic calculations are not given in detail. Nevertheless, improvements for conceptual design are suggested. As a result, it is shown that the controller works efficiently: the missile is able to hit the target with less than 12 m circular error of probability (CEP). Finally, studies and improvements are proposed.


Hovering Control of a Tilt-Wing UAV
Çakır, Hasan; Kurtuluş, Dilek Funda (2019-09-20)
In this study, the design and analysis of hovering controller of an UAV which is capable of doing vertical take-off and landing using the fixed six rotors placed on the tilt-wing and tilt-tail will be explained. The aircraft will have four rotors on the wing and two rotors on the tail. The main wing and horizontal tail will be capable of 90° tilting. Whole flight is separated into three flight modes, which are VTOL, Transition and Forward Flight, to have a robust control on aircraft. Only hover control of t...
Reinforcement learning control for helicopter landing in autorotation
Kopsa, Kadircan; Kutay, Ali Türker (2018-01-01)
This study presents an application of an actor-critic reinforcement learning method to the nonlinear problem of helicopter guidance during autorotation in order to achieve safe landing following engine power loss. A point mass model of an OH-58A helicopter in autorotation was built to simulate autorotation dynamics. The point-mass model includes equations of motion In vertical plane. The states of the point-mass model are the horizontal and vertical velocities, the horizontal and vertical positions, the rot...
Increasing air defense capability by optimizing burst distance
Türkuzan, Mehmet; Kocaoğlan, Erol; Department of Electrical and Electronics Engineering (2010)
In this thesis, burst distance is optimized to increase air defense capability for systems utilizing airburst munitions. A simulator program is created to use during the study by taking advantage of the MATLAB environment. While creating the simulator program, a munition path model is derived by using fourth order Runge-Kutta method. Then, simulations are conducted at different burst distances and related information are recorded. By using least square optimization method and gathered data, optimum burst di...
Automatic Landing Flare Control Design by Model-Following Control and Flight Test on X-Plane Flight Simulator
Cetin, Ender; Kutay, Ali Türker (2016-07-20)
The aim of this study is to design a landing control system and test it on X-Plane flight simulator. Model-Following control and H-Infinity output feedback control methods are used to design the controller. In the flare part of the automatic landing system, it is desired to reduce the rate of descent in order to make aircraft touch down softly. This is accomplished by exponential decay trajectory. The trajectory which is drawn by the referenced model is followed by the linearized aircraft model. The error b...
Dynamic modeling and control of a hybrid fin actuation system for an air-to-air missile
Çelik, Tayfun; Ciğeroğlu, Ender; Yazıcıoğlu, Yiğit; Department of Mechanical Engineering (2014)
Air-to-air missiles require high maneuverability. In order to obtain high maneuverability, hybrid fin actuation systems are used. In this study, a hybrid fin actuation system which is composed of aerodynamic control surfaces and thrust vector control is designed. Both aerodynamic and thrust vector control types are explained and the most suitable pair is determined for air-to-air missile. Then, the designed system is physically constructed and system identification procedure is performed. After that three d...
Citation Formats
Y. Günbatar, “Varying mass missile dynamics, guidance & control,” M.S. - Master of Science, Middle East Technical University, 2007.