Application of Adaptive Three-Position Control in the System of Automated Control of a Thermal Object

Abstract

Purpose of research. The control object was considered to be a thermal unit in the form of a modified two-tier tunnel furnace designed for the production of foam glass blocks. The main goal of this work was to improve the quality of products, reduce defects, and ultimately increase productivity by developing an automated system for controlling the thermal field of a technological unit for the production of foam glass blocks using an adaptive three-position control law with adaptation to the load of the average position of the regulator. Methods. At the initial stage, a functional automation scheme for a modified two-tier tunnel furnace was developed. To model dynamic discrete systems, a mathematical apparatus was used in the form of labeled Petri nets, which resulted in algorithmization of the technological process for the production of foam glass blocks. This solution to the problem should be used as a method of algorithmization and programming of the logic controller that is part of the automation system structure. The developed functional automation scheme can be converted into a mnemonic circuit, thereby implementing a SCADA system designed for control and visualization, diagnostics and monitoring of the process at a centralized control point, which is part of the automated workplace of the operator-technologist. The described approach to the development of an automated process control system has a generalized representation. The solution is methodological in nature, demonstrating the usability of the model in the form of a labeled Petri net. Results. In the course of research, a graph of operations of the production process with discrete adaptive threeposition control of the average position under load was developed. To check the correctness of the graph of operations, a tree of achievable markings was built, and its analysis was performed for compliance with security conditions and network liveliness. A block diagram of the main algorithm and the algorithm for adapting the controller's control program is developed. Conclusion. The described approach to the development of an automated process control system for the production of foam glass blocks has a generalized character, although it is illustrated by applying it to a specific object , since it allows changing both the number of variables xi , zi, and their functional purpose, that is, instead of sensors, pushers, valves, parameter values, for example, temperature, other automation elements and other physical variables and their parameters can be used. Thus, the presented solution is methodological in nature, demonstrating the convenience of using the model in the form of a Petri net and a tree of achievable markings for algorithmization and programming of a logic controller that is part of the automation system structure.