Stability research of systems with interval-define parameters

In the practice of designing a system of automatic control it can happen that the significances of individual parameters of the system are unknown and nonmeasurable and there is no statistical description of the system parameters. Uncertainty in parameters can occur because of different causes including the usage of simplified mathematical models and the inaccuracy of task solution of the unknown variables identification. Moreover, parameters of the control object can vary over the technological and operational factors (ageing and wear of equipment elements, fluctuations in temperature etc.). In all cases mentioned above the variations of such parameters of SAC are considered to be interval-defined since their changing can be defined by interval method only. The aim of the given work is a comparative analysis and research of a series of criteria of the systems stability with interval-defined parameters (gray systems). Stability of such systems is estimated either according to their interval matrix of the state or according to their characteristic polynomial.