Robust MIMO control-system design using eigenstructure assignment and QFT

An approach to robust control design for a multi-input/multi-output (MIMO) plant using eigenstructure assignment (EA) and quantitative feedback theory (QFT) is presented and applied to the design of a lateral flight control system. EA techniques are introduced to give an initial feedback control design for the nominal plant model, providing decoupling between the multiple control channels. The QFT method for single-input/single-output (SISO) plants is used to obtain robust stability under the given plant-parameter uncertainties. Detailed designs are conducted with both the proposed EA/QFT approach and the direct MIMO QFT approach. The design results demonstrate the good performance and features of the proposed EA/QFT approach that may be achieved.