Model-based solutions for structural coupling in flight control systems

Structural Coupling is the interaction between an aircraft's Flight Control System (FCS) and its structural and aero-dynamics. These interactions have the potential to cause significant problems to the aircraft, possibly through structural fatigue failure, or by corruption of sensor readings leading to degradation of the FCS loop. Presently notch filters are used to attenuate the sensor signals at the structural mode frequencies which cause significant problems. However, each of these notch filters adds a small amount of phase lag to the control loop which limits the performance of the FCS. This research has looked at using Kalman filters to provide an alternative approach to overcoming the structural coupling problem. [Continues.]