ROBUST MULTIRATE EIGENSTRUCTURE ASSIGNMENT WITH FLIGHT CONTROL APPLICATION

A recent result for multirate state feedback with fast and sf ow feedback loops is extended to output feedback. This multirate feedback structure is combined with eigenstructure assignment to design a lateral stability augmentation system operating at 50 Hz and a bank angle autopilot operating at 10 Hz for the linearized dynamics of the L-1011 aircraft. A new sufficient condition for robust stability of the multirate system in the presence of linear time-invariant continuous-time structured state-space uncertainty is proposed. A multiobjective optimization is used with both eigenstructure assignment and robustness objectives. A hybrid simulation of the continuous aircraft dynamics demonstrates that the robust multirate eigenstructure assignment Right control system exhibits excellent decoupling between the yaw and rod dynamics.