Fault tolerant flight control for a class of control surface failures

We use multiobjective optimization to design a flight control law which achieves acceptable handling qualities for a class of control surface failures. Our class includes the symmetric failure of any one control surface being stuck at its trim value where it is not known in advance which surface will fail. We compare an eigenstructure assignment gain designed for the unfailed aircraft with a multiobjective optimization gain designed to achieve: 1) the same response for the unfailed condition as was obtained using eigenstructure assignment; and 2) MIL-F-8785C specifications for all failure conditions belonging to our class.