Optimization based synthesis of state derivative feedback controllers for retarded systems

The paper presents an optimization based algorithm for stabilizing retarded systems using a state derivative feedback controller. It is shown that an application of such a controller results in neutral dynamics of the closed loop system if small feedback delays occur. Therefore, the strong stability theory of neutral systems needs to be considered in the controller synthesis problem. The stabilization approach is based on minimizing the spectral abscissa of the closed loop system over the controller parameter space, subject to a strong stability constraint.