Adaptive two-stage fuzzy temperature control for an electroheat system

In this paper, we construct a simple adaptive two-stage fuzzy temperature tracking controller for a commercial electroheat system. Being not well iso-lated from the environment, it is hard to build an analytical model for the system due to heat convec-tion caused by a fan for heat mixing in the chamber, heat leakage to the environment, variation of the en-vironment temperature, and uncertain nonlinear heating dynamics. Also, as a commercial product by using cheap heater coils and without equipping a cooling system, this system usually has a bad tran-sient response such as a long rise time, a large over-shoot, and a long settling time. Moreover, tempera-ture tracking at the steady-state phase is not easy to maintain due to heat interaction with the environ-ment. Here, in the presence of the unknown system dynamics, we use a two-stage fuzzy controller to im-prove the transient response. Furthermore, a simple fine-tuning adaptive control scheme is proposed to overcome environmental influence and ensure track-ing of the temperature setting. Simulation study and experimental results show good performance of the adaptive fuzzy temperature control system.