Nonlinear PI-controller design for a continuous-flow furnace via continuous gain scheduling

The continuous-flow furnace under investigation consists of one heating zone with a fixed temperature. The material to be heated is moved through the furnace by a conveyor unit, the conveyor speed being the only system input for controlling the output temperature of the material flow. As a mathematical model a bilinear distributed parameter system is established. To control the output temperature one applies a nonlinear PI controller designed via a new gain scheduling approach based on linearization families. This technique condenses a family of linear PI controllers for a continuum of operating points of the plant into one nonlinear PI controller. Linear design methods are therefore transferred to the nonlinear plant.