Active gust load alleviation system for flexible aircraft: Mixed feedforward/feedback approach

Lightweight flexible blended-wing-body (BWB) aircraft concept seems as a highly promising configuration for future high capacity airliners which suffers from reduced stiffness for disturbance loads such as gusts. A robust feedforward gust load alleviation system (GLAS) was developed to alleviate the gust loading. This paper focuses on designing a feedback controller which would improve the robust performance of the feedforward controller in reducing the peaks in wing root moments at very short gust lengths. The simulation results show that when the new feedback compensator is engaged with the feedforward controller, the performance of the GLAS system is improved significantly in terms of reduction in wing root moments for shorter as well as for longer gusts. This reduction in the wing root moment's peak provides potential structural benefits and weight savings.