Reduced Order Observer (DGO) based State Variable Design of Two Loop Lateral Missile Autopilot in Pitch Plane

–In this paper, first the transfer function and block diagram model of a flight path rate demand autopilot (two loop) in pitch plane has been shown and then its state model has been developed. Then state feedback controller has been designed. Thereafter both of Luenberger and Das & Ghosal Observers (DGO) are implemented for the above said two loop autopilot. Finally the system, observer and state feedback controller are integrated in one unit and a comparative study between Luenberger and Das & Ghosal observer is done. It will be shown that the observers are able to track the system states i.e. estimate the system states very quickly and with high degree of accuracy even if the initial states of the plant and observer are mismatched. It has also been established that addition of an observer (an auxiliary dynamic system) to the system does not impair the system stability; it only appends its own poles (Eigen values) with the original system poles. Keywords––Missile Autopilot (two loop and three loop), Angle of attack, Pitch/Yaw Motion, Flight path rate demand, Guidance and Control, Gyroscope, Accelerometers, Aerodynamic control, Luenberger Observer, Das & Ghosal Observer, Generalized Matrix Inverse.