Frequency-Domain Robust Performance Condition for Controller Uncertainty in SISO LTI Systems : A Geometric Approach

Abstract EN

This paper deals with the robust performance problem of a linear time-invariant control system in the presence of robust controller uncertainty.

Assuming that plant uncertainty is modeled as an additive perturbation, a geometrical approach is followed in order to find a necessary and sufficient condition for robust performance in the form of a bound on the magnitude of controller uncertainty.

This frequency domain bound is derived by converting the problem into an optimization problem, whose solution is shown to be more time-efficient than a conventional structured singular value calculation.

The bound on controller uncertainty can be used in controller order reduction and implementation problems.