HVAC Control in the New Millennium.pdf - HVAC.Amickracing

Artificial Intelligence, Fuzzy Logic and ControlFuzzy ControlFuzzy controllers have rules that are used to calculate the controlaction. Each rule is an expression about the control action to be taken inresponse to a given set of conditions. These rules have the followinggeneral format:IF (CONDITION) THEN ACTIONThe condition may include AND/OR operations. The fuzzy controlleruses the inference process, (Figure 6-7), which has several ruleprocesses and produces a single logical sum. Each rule process has itsconditions (antecedent) and a conclusion (consequence). The conclusionis reached when the conditions are satisfied. The conclusions are thensent through a logical summer.The defuzzification operation then unifies the results of the ruleprocess and produces a final output that can be interfaced to most typesof output devices.The problem of energy use in HVAC can be used to illustrate theoperation of a fuzzy controller. A set of instinctive judgments is trans-Figure 6-7. Operation of fuzzy control©2001 by The Fairmont Press, Inc. All rights reserved.