Testing signals formation for identification of heat power objects and control systems comparison

摘要

The purpose of this study is to validate the schedule of testing impacts to compensate for uncontrolled disturbances in furnaces conditions for heating of metals before rolling. Two problems have been solved in this paper: the formation of the input testing signal effects to determine the dynamic characteristics of an object by its transient response; prompt obtaining of valid information about the effectiveness of different methods or control algorithms application. To compensate for the low-frequency and random perturbations the method of forming the signal identifying impacts on the basis of the Walsh orthogonal functions system has been proposed in this research. Uncontrolled process disturbances acting on the actual thermal energy objects distort the information on their dynamic parameters, which leads to deterioration of control quality. And it is possible to note that the characteristics of the object have considerable inertia and the frequency of perturbations is low; the characteristics have a vertical and horizontal drift. The influence of these disturbances can be reduced considerably due to the proper formation of input testing signal impacts. The influence of the signal impacts in the identification of the inertial object with delay has been tested by the authors on the developed laboratory-scale plant and has shown high efficiency. The second task is the prompt definition of the relative cost-effectiveness of two methods for the process control of metal heating before rolling. Conducted by the authors, the production experiment in which the switching of the compared systems has also been produced according to a specially formed schedule based on the system of Walsh orthogonal functions has been considered in this paper. The results obtained in the experiment give grounds to assert that the proposed formation of the switching schedule allows virtually eliminating the effect of the main disturbing random factors (production volume, the proportion of hot shrink fit metal) on a comparative indicator of the effectiveness of two methods of metal heating control.