Minimal order disturbance estimator design for aircraft load alleviation control

In this paper a novel approach to design linear disturbance estimators is presented. The model based design approach relies on advanced nullspace computation techniques and explicit facilitates an estimators design of low state dimension. This reduces the dependencies on the underlying design models and thereby increases robustness against modeling errors. To further support this low order characteristics an advanced model approximation technique for preprocessing high order design models is presented. The proposed approaches are applied to a generic model of a business jet aircraft. The derived disturbance estimator is used in a control algorithm to reduce the wing bending moments on the aircraft in case of wind gusts. Both, the disturbance estimator together and the load alleviation controller are verified in a non-linear closed loop aircraft simulation model.