Novel fuzzy PID control and application to HVAC systems

In order to extend the application of fuzzy controller to nonlinear systems, a new fuzzy control strategy converted directly from the PID controller is proposed. The mathematical relation between the parameters of the fuzzy con-troller and the linear gain of the conventional PID controller is derived based on the structure analysis of fuzzy controller. Based on this mathematical relation, the fuzzy controller is designed through the gain-tuning in the PID controller. Fur-thermore, the improved variable universe method is employed to optimize the parameter tuning of the fuzzy controller on line. This new fuzzy controller is also applied to energy-saving control in heating, ventilating, and air-conditioning(HVAC) systems. The comparison of the simulation results between this fuzzy controller and the conventional PID controller shows that this fuzzy controller is effective and the algorithm provides less overshoot, shorter setting time and better robustness, etc.