Resource-saving optimal control of energy-intensive process of work part thermochemical treatment

Abstract

Paper discusses approach to the resource-saving optimal control algorithms development, which includes problem oriented mathematical modeling of the process, determination of the tolerance limits for controlling action changes and condition of thermochemical treatment process as a subject under control, optimality criteria formalization and determination. Specified and solved critical problems for resource-saving optimal control of energy-intensive thermochemical process of work parts treatment on the maximum accuracy and speed of operation criteria. Alternance optimization method was used for optimal control problems solution, which allows to determine not only interval of constancy size but also maximum achievable control accuracy in every subset of intervals. Analytical mathematical model of vacuum carburizing in an acetylene atmosphere with variable coefficients of mass transfer was developed, which takes into consideration different mechanisms of carbon mass transfer from the atmosphere into the work part surfaces at the saturation and diffusion stages. Dependences of the carburization accuracy on the optimal control parameters were constructed. Influence of the technological constraints on the control quality was analyzed. Suggested approach demonstrated high energy efficiency.