Identifying design parameters for fuzzy control of staged ventilation control systems

Conventional staged ventilation systems are commonly used in agriculture to maintain interior environments near desired conditions for livestock housing and greenhouses. This paper identifies design parameters for fuzzy-based control of these staged ventilation systems. A simple non-steady state heat balance is used in conjunction with a broiler house simulation model, and coupled with a model for the control system, to simulate control system performance. Difficulties with implementation of conventional staged ventilation control, and the proposed fuzzy inference technique, arise because of the discontinuous nature of these highly non-linear systems. Comparisons between the new fuzzy stage controller and conventional staged control are made. Effects of varying the identified design parameters for the fuzzy stage controller, including different degrees of control precision and energy use, rule base complexity, and the rate of change of house temperature are made. Results indicate that existing staged ventilation control systems which utilize microprocessors could realize significantly enhanced control flexibility by a simple software modification to incorporate the fuzzy staged controller method. (C) 2001 Elsevier Science B.V. All rights reserved.