The Study On The Control System Of Aerodynamic Missile Based On Fractional Calculus

PID controllers belong to the dominating flight controllers and therefore there is a continuous effort to improve their quality.Looking forward to developing the merit of the PID controllers and overcoming the flaw of the PID controllers, one of the possibilities to improve PID controllers is to use fractional order controllers based on the fractional calculus. The novelty of the proposed controllers consists in the extension of derivation and integration order from integer to non-integer order. The fractional order controllers mainly have two advantages relating to the integral-order controllers, the one is that it has more degrees of freedom in the model, the other is that it has a "memory" in model, the memory insures the history and its impact to present and future. At last, the fractional controllers are used to control the aerodynamic missile in order to improve the flight performance of the missile.In this thesis, the elementary knowledge of fractional calculus, such as history, definitions, properties and digital method, are outlined. The stability, controllability and observability of fractional order system are investigated. The parameters tuning method of the fractional order controllers are determined according to the given requirements. Integrating flight characteristic of the aerodynamic missile, the PI~λD controllers are applied to attitude autopilot control of navigational stage and the PD~μ controllers are applied to overload autopilot control of homing stage.The simulation results show that the fractional order controllers are not sensitive to the changes of control parameters and controlled object parameters. At the same time, it has more flexible structure and stronger robustness. The fractional calculus has been demonstrated to a useful tool for flight control and the designed fractional order controllers can be implemented to improve the missile performance. The missile can obtain a greater anti-jamming ability, a more excellent precision and an agile maneuverability.