STABILITY ANALYSIS OF A MISSILE CONTROL-SYSTEM WITH A DYNAMIC INVERSION CONTROLLER

The closed-loop stability is examined of a bank;to-turn, air-to-air mi ssile with a dynamic inversion controller using a two-timescale separa tion. A state-space formulation for the alpha, beta, and phi dynamics of the missile, assuming the inner-loop dynamic inversion is performed exactly, is presented. It is then shown that, under Certain assumptio ns, the exponential stability of the alpha, beta, and phi dynamics abo ut the commanded values can be guaranteed if the inner-loop design fre quency is large enough. An example calculation of the required inner-l oop frequency to guarantee stability is done for a particular bank-to- turn missile. Finally, nonlinear six-degree of-freedom simulation resu lts of a maneuver performed with the dynamic inversion controller are presented.