Industrial Automatic Control Systems and Controllers Annotation << Back Determination of the Structure of Models of Undetermined Dynamic Objects in Systems of on-off Regulation Yu.P. Kirin, V.A. Tikhonov The article contains the questions of determining the structure of models of indeterminate dynamic objects operating in conditions of normal operation in closed systems of two-position control. Considered are the approaches to solving this problem. It is noted that, with the current state of scientific research, the task of determining the structure of mathematical models presupposes the presence of a priori and a posteriori information about the objects under investigation and is based on the intuition of the developer of control systems. As a prior information for choosing the structure of models of indeterminate dynamic objects, it is suggested to use differential equations with constant coeffi cients, known in the theory of two-position regulation, describing the dynamic properties of stationary objects of the fi rst order without self-leveling and with self-leveling. A posteriori information is obtained from an analysis of self-oscillatory regimes of two-position regulation of a real undetermined dynamic object. The connection of self-oscillating modes with the task of determining the structure of the object model is shown. It is proposed to use the period of self-oscillations as an identifi cation interval on which an indefi nite dynamic object is considered quasi-stationary, in the process of functioning as a family of quasi-stationary objects that differ in different identifi cation intervals by values of dynamic parameters and perturbations. On the basis of a priori and a posteriori information, a hypothesis is made about the possibility of representing the structures of models of real indeterminate dynamic objects by differential equations with variable coeffi cients describing the dynamic properties of nonstationary fi rst-order objects in two-position systems without self-leveling and self-leveling. Practical confi rmation of the hypothesis about the proposed model structures is obtained as a result of solving the problem of parametric identifi cation of undefi ned dynamic objects. Keywords: mathematical model; indeterminate dynamic object; two-position regulation system; identifi cation interval; self-oscillations. Contacts: E-mail: klu2010@mail.ru, E-mail: tihonov1986@yandex.ru Pp. 11-17.