A multivariable PI controller for nonlinear ill-conditioned electrical tubular ovens

The control of multivariable systems has been a wide area for investigation of new methods and techniques. One of the primary objectives of the control design problem is to overcome the usually existent cross-coupling between inputs and outputs which obscures the effects of a specific loop controller on the system behavior. In the case of temperature control, the problem is still more challenging due to the time delays and nonlinearities involved in the process. This paper considers the application of frequency domain techniques to the design of multivariable feedback controllers for nonlinear, multiple-heating-zones, electrical oven systems. Simulation results are presented.