Composite Anti-Disturbance Reference Model L2-L∞ Control for Helicopter Slung Load System

This work considers the anti-disturbance model reference L-2-L-infinity control for the helicopter slung load system subject to unknown disturbances. Initially, a linear model is derived based on the nonlinear dynamics of a helicopter with slung load. The uncertainty and disturbances are jointly considered in the controller design. Then, by designing a disturbance observer and using robust L-2-L-infinity control method, the state feedback control and dynamic output feedback control are respectively analyzed, and two sufficient conditions on deriving the observer gain and controller one are presented via the linear matrix inequality (LMI) form, which can guarantee the helicopter slung load system to asymptotically track the reference model with L-2-L-infinity performance. Finally, some simulation results are presented to show the effectiveness of the proposed methods.