H∞ optimal controllers for a distributed model of an unstable aircraft

The authors discuss the numerical computation of H^∞ optimal controllers for an unstable aircraft model with a time delay. It is shown that the optimal H^∞ controller for this infinite-dimensional model can be computed from a finite determinantal formula. The properties of the optimal controller are examined. For a particular choice of weights, the authors illustrate with an example that the optimal controller is stable and continuous. They examine approximations of this controller, and illustrate suboptimality of the controllers obtained from these approximations