Use of nonlinear controller and observer theory for furnace temperature control

This paper explores the application of nonlinear controller and observer theory to the practical problem of temperature control in a gas fired furnace. The furnace design under consideration can be thought of as a gas filled rectangular enclosure bounded by insulating walls containing a heat sink. Heat input is achieved via a single burner located in one of the end walls. Although this represents the simplest design possible-a single burner arrangement such a plant could legitimately represent an industrial furnace for the firing of ceramics. The control problem considered here involves altering the fuel flow rate by manipulating a valve so that the measured temperature at some point in the furnace follows a specified temperature/time profile. It is assumed that an independent regulator exists which maintains the fuel/air ratio required for efficient and safe combustion.