Robust Gust Load Alleviation Control using Disturbance Observer for Generic Flexible Wing Aircraft in Cruising Condition

This paper deals with robust gust load alleviation control design for a flexible wing aircraft in cruising condition. Using an array of control surfaces called the Variable Camber Continuous Trailing Edge Flap, the gust load alleviation controller minimizes the structural load on the aircraft wing induced by a gust disturbance. The control terms are separated into two channels, rigid and elastic control input. Only the elastic control input is used for gust load alleviation while rigid control input is reserved for fundamental trajectory-level flight control. Utilizing equivalent input disturbance theory, the virtual input disturbance is calculated and compensated for by a disturbance observer robust control algorithm. Simulation results are provided with detailed analysis, proving the validity of the proposed method.