Amin Aeenmehr - Faculty of Engineering, Shohadaye Hoveizeh University of Technology, Dasht-e-Azadegan, Iran
Nasser Erfani Majd - Faculty of Engineering, Shohadaye Hoveizeh University of Technology, Dasht-e-Azadegan, Iran

In this paper, the application of firefly algorithm to control a room temperature using a heat pump isinvestigated. In fact, the thermal plant uses a PID controller tuned by firefly algorithm to make the temperature of theroom fixed at the level of desired comfort. Among controllers, PID controllers are very popular and frequently used in awide range of industrial applications especially thermal plants. There are a number of classical techniques to set PIDcontroller parameters such as Ziegler-Nichols and Astrom-Haaglund to name a few. Those mentioned techniques arecalled heuristic methods. But some meta-heuristic methods can be used to tune PID controller gains which are inspiredby nature phenomena. One of them is firefly algorithm which has been introduced for a decade to industrialapplications. The purpose of applying such algorithm is minimizing a cost function by optimal set of some influentialfactors in the process.Therefore, in this paper applying firefly algorithm to tune PID controller is proposed. First of all, a model of thethermal plant is derived by using physical equations governing the thermal plant. PID controller, then, was tuned by thefirefly algorithm and applied to plant. The whole closed-loop control system was simulated in MATLAB. The resultsdepicted that the proposed controller made the time-domain performance improved considerably.

firefly algorithm, PID controller, heat pump, building, temperature control