Industrial Automatic Control Systems and Controllers Annotation << Back Piecewise Linear Approximation of Self-oscillations in the System of Two-position Temperature Control of Vacuum Separation of Sponge Titanium Yu.P. Kirin, V.A. Tikhonov The method of piecewise linear approximation of self-oscillations in the system of two-position regulation of the temperature of the heating zone of the industrial apparatus of vacuum separation of sponge titanium is proposed to solve the problem of parametric identifi cation of the mathematical model of the heating zone represented by a non-stationary control object. The structure of the mathematical model of the heating zone is assumed to be known and given by a differential equation with variable coeffi cients, which consider the dynamic parameters and perturbation of the heating zone. The solution of the parametric identifi cation problem involves splitting the working self-oscillating modes of the two-position temperature control of the heating zone into a series of individual periods of temperature self-oscillations-identifi cation intervals on which the heating zone is viewed by a quasi-stationary control object during the vacuum separation process at different identifi cation intervals-as a family of quasi-stationary control objects. This approach allows us to describe the dynamics of the heating zone on the identifi cation intervals by differential equations with constant coefficients. This made it possible to replace the complex initial model of a nonstationary object of family control with fairly simple stationary models for which a system of finite equations is obtained that approximates the self-oscillating modes of on-off temperature control by linear functions on the identifi cation intervals and establishes the relationship between the self-oscillation parameters and the unknown coeffi cients of the differential equation. The solution of the system of fi nite equations determines the dynamic parameters and identifi es the disturbance of the control object – the heat consumed by the heating zone during the vacuum separation for the evaporation of magnesium impurities and magnesium chloride from the titanium sponge. The results of the perturbation identifi cation are used to control the duration of the vacuum separation and the cooling mode of the condenser of the separation apparatus. Keywords: vacuum separation of spongy titanium; two-position control; self-oscillations; identifi cation; piecewise linear approximation. Contacts: E-mail: klu2010@mail.ru, E-mail: tihonov1986@yandex.ru Pp. 09-15.