Robust Stability Limit of Delayed Dynamical Systems

Computation of the stability limit of systems with time delay is essential in many research and industrial applications. Most of the computational methods consider the exact model of the system, and do not take into account the uncertainties. However, the stability charts are highly sensitive to the change of input parameters, such as eigenfrequency and time-delay. Furthermore, the computation of the dense stability lobe structure is numerically intensive; however, in some cases an envelope of these stability boundaries would be sufficient. A method has been developed to determine the robust stability limits of delayed dynamical systems, which is insensitive to fluctuation of system parameters. It is shown, that the resultant robust stability limits form the lower envelopes of the stability lobe structure.