PID in Smart Buildings

Abstract: This work details the design and implementationof PID controllers in smart buildings coupled with the useof Wireless Sensor Networks. The main application that isinvestigated is the control of air temperature in a building. Twomathematical models of this system are presented: a simplifiedfirst order system, and a more complex second order system,both based on physical knowledge. Additionally, both modelsare based on a physical implementation to be tested. Three PIDcontrollers have been designed to control this system, two for thefirst order model and one for the second order model. A physicaltest-bed has been implemented with a styrofoam box acting as abuilding. The performance of the controllers and the quality ofthe mathematical description has been investigated by comparingthe simulations and the experimental results. The effect of aconstant feedback delay was simulated using F2 and the systemappeared to be highly resistant to the effects of the delay. Thefirst order system proved to be a better system description,and the second controller F2 had the best performance. Theeffects of packet loss upon the system is also investigated anda well-functioning compensation method is proposed. Finally, afew further areas of applications for PID control in buildingsare discussed, such as ventilation, air humidity, and hydroponicfarming.