A pursuit evasion game between a missile and an aircraft

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2002
Şahin, Keziban Didem
In this thesis an intelligent mechanism is found to help the pilot of an aircraft under missile threat in making decisions to evade from the missile. To make the system realistic, flight simulations for both aircraft and missile are designed and a pursuit evasion game between them is created. In this system, capabilities of the aircraft and the missile are improved both. Flight simulations are made of three main components. These are the dynamic model of the vehicle, its guidance and control units. In this work, form of the dynamic models are studied for both the aircraft and the missile. It is found that they are the similar except for some minor differences. Implementation for both have been done. IllFor missile's guidance two different guidance methods are used and tested. The first one is a -well known method "Proportional Navigation Guidance" and the second one is "Fuzzy Logic Composite Guidance Law". Results obtained from both are compared. The control unit of the missile is made up of three autopilots. In this work among different autopilot design alternatives, rate command tracking autopilots are chosen and implemented. The above explained scheme is repeated for the aircraft. Its dynamic model is created, a guidance unit and control system is designed and implemented. Generally aircrafts do not need guidance units as missiles. This task is realized by the pilot But for aircrafts under missile threat it is better to have a decision mechanism to say what to do automatically to the pilot. It can make more objective decisions without hesitation. So an intelligent guidance unit based on fuzzy logic is designed for the aircraft. The control system of the aircraft is a little bit more complex than that of the missile. It is composed of stability augmentation systems, attitude control systems and flight path control systems. Here all are studied and the necessary ones for the simulation are determined and implemented. Furthermore, in real life it is usually not enough to make evasion maneuvers for an aircraft to escape from missile threat, so some other methods should be used additionally. These are called electronic warfare systems. Here a pseudo chaff/flare model is created. By this way probability of evasion is increased. Results of games with and without using chaff/flare are compared. Finally some optimization work is done over all membership functions of the aircraft's guidance unit The performance of the aircraft's guidance unit before and after optimization is observed
Citation Formats
K. D. Şahin, “A pursuit evasion game between a missile and an aircraft,” M.S. - Master of Science, Middle East Technical University, 2002.