Research and Application on Two-Stage Fuzzy Temperature Control System for Industrial Heating Furnace

Industrial heating furnace has a great deal of special characteristics such as big capacity, long lag and non-linear trait, etc. In order to control it better, we present a sort of two-stage fuzzy temperature control algorithm. The first-stage controller is responsible for determining the control variable according to deviation information of controlled variable. The second-stage controller takes charges of adjusting the control variable coming from the first-stage controller through other process parameters. The algorithm takes full account of the impact of many process parameters on controlled variable. It uses two-stage fuzzy controller to decentralize process of control parameters, which makes it easy to extract fuzzy rules, greatly reduces the number of fuzzy rules and produces reasonable control outputs. Based on this algorithm, we have designed a two-stage fuzzy temperature control system for industrial heating furnace. Engineering applications show that the control algorithm has a lot of advantages such as high accuracy, strong robustness, etc. Its quality is superior to conventional control and it is suitable for long lag, non-linear system in particular.