A sliding mode output feedback controller for an aircraft system with flexible modes

Considers a framework for sliding mode control design. LMI based techniques are used to design the output dependent switching surface and to determine a control law to effect a sliding motion. The reachability condition is not required to be satisfied globally. Instead sliding is only expected to take place within a subset of the state-space referred to as the sliding patch. The LMI optimisation seeks to maximise the sliding patch subject to certain constraints. The efficacy of the proposed control design method is demonstrated on a non-trivial design example-an aircraft system representation which includes the flexible modes of the airframe.