Guided missiles are among the most effective threats against air platforms. Aircraft and helicopter losses in the last decades were mostly due to guided missiles, 70% of which were infrared guided missiles. Today, there are as many as 500,000 shoulder-fired missiles in military arsenals around the world, whose guidance algorithms enable them to track the desired trajectories very precisely. In this thesis, main focus is on defining infrared missile guidance and control algorithms in order to study on various target-missile scenarios for the effectiveness of these algorithms. First, a mathematical model of a generic missile is given. Then the flight control system of the missile is created by using LQR and PID controllers. Different kinds of PNG algorithms applied to an infrared missile are presented. The seeker part of the infrared missile is also discussed. The effectiveness of guidance algorithms are studied based on different target &ndash / missile scenarios and the responses of them to IR countermeasures are also observed. This study shows that different guidance algorithms can be used for different scenarios. If suitable algorithms are combined and suitable constants are applied, the guided missile can track the target very precisely. In addition, the seeker part has to be improved with tracking algorithms in order to recognize IR-countermeasures and not to follow them.

An anti-tank guided missile is a weapon system primarily designed to hit and destroy armored tanks and other armored vehicles. Developed first-generation command-guided and second-generation semi-automatic command guided missiles had many disadvantages and lower hit rates. For that reason, third generation imaging infrared fire-and-forget missile concept is very popular nowadays. In this thesis, mainly, a mathematical model for a fire-and-forget anti-tank missile is developed and a flight control autopilot design is presented using PID and LQR techniques. For target tracking purposes, &ldquo / correlation&rdquo / , &ldquo / centroid&rdquo / and &ldquo / active contour&rdquo / algorithms are studied and these algorithms are tested over some scenarios for maximizing hit rate. Different target scenarios and countermeasures are discussed in an artificially created virtual environment.

Multidisciplinary design optimization of aerospace vehicles has attracted interest of many researchers. Well known aerospace companies are developing tools for the mutlidisciplinary design optimization. However, the multiobjective optimization of the design is a new and important area investigated very little by the researchers. This thesis will examine the approaches to the multiobjective and mutlidisciplinary design optimization of rockets and missiles. In the study, multiobjective optimization method called MC-MOSA will be used.

Cruise missile mission planning is a key activity of cruise missile operations. Ground planning activities aim at low observable missions that have high probability of success. These activities include end game planning, route planning and launch planning. While end game planning tries to optimize end game parameters for maximum effectiveness, route planning tries to maximize survivability and enable navigational supports by determining the waypoints to from launch zone to target through a defended area. And lastly, planner tries to find the appropriate launch parameters that will prohibit platform to contact enemy agents. Mission rehearsal is the execution of the planned mission in a virtual environment that will be constructed with the data that drives the planning process. Mission rehearsal will support planners by providing possible results of the planned mission. Stochastic processes of the execution of the planned mission will be incorporated in the simulation of the combat. Along with platform, cruise missile and target, other players like SAM Sites or Search Radars (Early Warning Radars) will be incorporated in the rehearsal process.

The protection of aircraft against shoulder fired heat seeking missiles is of growing concern in the aviation community. This thesis presents a simple method for shielding the infrared signature of a jet engine from heat seeking missiles. The research efforts investigated two approaches to shield the thermal signature of the Noel Penny Type 401 turbojet at the Texas A&M University Propulsion Lab Test Cell. First, liquid nitrogen was injected through a manifold at a flow rate equivalent to the flow rate of exhaust gases, producing a small temperature reduction in the exhaust but no infrared shielding. Second, water was injected at a flow rate of 13% of the flow of exhaust gases, producing a greater temperature reduction and some shielding. Water was then injected through a manifold at a flow rate of 118% of the flow rate of exhaust gases, producing a substantial reduction in temperature and complete shielding of the infrared signature. Additionally, numerical simulations were performed using FLUENT to support these experiments. Results are presented in the form of thermocouple data and thermal images from the experiments, and in the form of temperature contours and streamtraces from the simulations.

<p>Abstract</p><p>The focus of this paper is to discuss ballistic missile defense (BMD) systems and their impact on international relations. I have a profound interest in the correlation between technological innovation/improvement and changes in international politics. I have therefore chosen the impact of BMD on global politics as the subject of discussion in my paper.</p><p>I begin the discussion by describing the technological segment of Ballistic Missile Defense systems, after which I indulge in the political aspect of it. There are three primary actors in the field: the United States of America, China, Russia. These three are the main focus of the debate, though not the only ones. During the Cold War it was the USA and Russia which pursued BMDS with most vigor, with China keeping a close eye on their progress as well as initiating its own BMD program. The emergence of the “New World Order” in the aftermath of the Cold War resulted in restructuring and re-organizing of the countries` strategic thinking, interests as well as defenses. The strongly criticized 2002 US withdrawal from the Anti-Ballistic Missile (ABM) Treaty of 1972 became the latest milestone in the sphere of strategic defenses. US withdrawal from the Treaty paves way for a new kind of arms race between the three major powers of today: USA, China, Russia.</p><p>My conclusion is that US policy regarding strategic defenses is completely unacceptable. The US quest for “invulnerability”, by many experts seen as futile, is extremely dangerous and just another proof that USA continues to relentlessly pursue complete global military, political and economic domination. The international community, with China and Russia leading, must not ignore US strategic defense ambitions and it must act today. Tomorrow might be too late.</p>

<p>Robust control design has become a major research area during the last twenty years and there are nowadays several robust design methods available. One example of such a method is the robust loop shaping method that was developed by K. Glover and D. C. MacFarlane in the late 1980s. The idea of this method is to use decentralized controller design to give the singular values of the loop gain a desired shape. This step is called Loop Shaping and it is followed by a Robust Stabilization procedure, which aims to give the closed loop system a maximum degree of stability margins. In this thesis, the robust loop shaping method is used to design a gain scheduled controller for a missile. The report consists of three parts, where the first part introduces the Robust Loop Shaping theory and a Gain Scheduling approach. The second part discusses the missile and its characteristics. In the third part a controller is designed and a short analysis of the closed loop system is performed. A scheduled controller is implemented in a nonlinear environment, in which performance and robustness are tested. Robust Loop Shaping is easy to use and simulations show that the resulting controller is able to cope with model perturbations without considerable loss in performance. The missile should be able to operate in a large speed interval. There, it is shown that a single controller does not stabilize the missile everywhere. The gain scheduled controller is however able to do so, which is shown by means of simulations.</p>

<p>This thesis has been performed at SAAB Bofors Dynamics. The purpose was to derive a robust control design for a nonlinear missile using backstepping. A particularly interesting matter was to see how different design choices affect the robustness. Backstepping is a relatively new design method for nonlinear systems which leads to globally stabilizing control laws. By making wise decisions in the design the resulting closed loop can receive significant robustness. The method also makes it possible to benefit from naturally stabilizing aerodynamic forces and momentums. It is based on Lyapunov theory and the control laws and a Lyapunov function are derived simultaneously. This Lyapunov function is used to guarantee stability. In this thesis the control laws for the missile are first derived by using backstepping. The missile dynamics are described with aerodynamic coeffcients with corresponding uncertainties. The robustness of the design w.r.t. the aerodynamic uncertainties is then studied further in detail. One way to analyze how the stability is affected by the errors in the coeffcients is presented. To improve the robustness and remove static errors, dynamics are introduced in the control laws by adding an integrator. One conclusion that has been reached is that it is hard to immediately determine how a certain design choice affects the robustness. Instead it is at the point when algebraic expressions for the closed loop system have been obtained, that it is possible to analyze the affects of a certain design choice. The designed control laws are evaluated by simulations which shows satisfactory results.</p>

Thesis--School of Advanced Airpower Studies, Maxwell Air Force Base, Ala., 1992-93. / Title from title screen (viewed Oct. 28, 2003). "28 June 1993." Includes bibliographical references.

Thesis (M.A. in National Security Affairs)--Naval Postgraduate School, September 2003. / Thesis advisor(s): H. Lyman Miller, Gaye Christoffersen. Includes bibliographical references (p. 91-96). Also available online.