Dynamic Model to Tune a Climate Control Algorithm in Pig Houses with Natural Ventilation

Abstract

Algorithms for environmental control in livestock buildings have to be tuned for optimum response of actuators. For tuning, a simple, but dynamic, climate model for a pig house was formulated and validated to predict the environmental changes in a pig house with natural ventilation under varying conditions. A control algorithm was included in the model and tuning of the algorithm has been performed with the model. The tuned algorithm was implemented in a climate controller and data on the results are presented. It was concluded that the model can be used to simulate room temperature and carbon dioxide concentration in heated pig houses with natural ventilation. The dynamics as well as the actual levels of climate parameters showed agreement between simulation results and actual results. The model can be used to find gain factors and time constants for PID-controllers in algorithms for control of room temperature, air quality, and ventilation rate in natural ventilated pig houses. This would enhance fast and accurate tuning controllers in livestock buildings with natural ventilation as compared to on-site hand tuning.