Many real world engineering systems are sensitive to temperature, and temperature control is vital to the success and operation of a broad spectrum of engineering applications. This paper investigates the use of numerically generated frequency response data to simulate the control system behavior of a simple but realistic finite element based nonlinear thermal model.
Using an IDEAS TMG finite element model, a thermal control system Bode plot was computed. The Bode plot was then used to determine the transfer function of the thermal system and design an appropriate control compensator to implement thermal control.
The performance of the compensated thermal system was then predicted first by MATLAB, and second by TMG. The response predicted by MATLAB using transfer functions was corroborated by its close agreement with a TMG finite element transient response simulation.
Nonlinear thermal effects, such as heat transfer by radiation, are addressed, and their impact on control system performance is explored. Lastly, the advantages of using a transfer function approach to control system analysis, as opposed to control tuning by trial and error, are outlined, and possibilities are suggested for extending the methods and techniques presented in this work to other types of thermal control systems.
