Before you modify a fuzzy system, you must familiarize yourself with the design of the system. Complete the following steps to open and observe the greenhouse fuzzy system in the Fuzzy System Designer.
Select Tools�Control Design and Simulation�Fuzzy System Designer to launch the Fuzzy System Designer.
Select File�Open and navigate to greenhouse.fs in the labview\examples\control\fuzzy\Dynamic greenhouse controller directory.
Click the OK button to open the greenhouse fuzzy system in the file dialog box. The Variables page displays details about the input and output variables of the fuzzy system.
Observe the input and output linguistic variables. The greenhouse fuzzy system has two input variables, Temperature and Humidity, and two output variables, Electric Roof and Water Spills.
Observe the ranges and membership functions for the linguistic variables. For example, the Temperature input variable represents the temperature, in degrees Celsius, inside the greenhouse, with a range of 0 to 50 and three membership functions: Cold, Normal, and Warm. You can see on the Input variable membership functions graph that a trapezoid function represents the shape of the Cold membership function. The left base, left top, right top, and right base points of this membership function are 0, 0, 13, and 21, respectively.
Click the Rules tab to display the Rules page. The Rules list displays nine rules for the fuzzy system, which correspond to all possible combinations of the membership functions of the two input linguistic variables. Also notice that the Defuzzification method for the fuzzy system is Center of Area (CoA).
Select the first rule in the Rules list: IF 'Temperature' IS 'Cold' AND 'Humidity' IS 'Dry' THEN 'Electric Roof' IS 'Closed' ALSO 'Water Spills' IS 'Moderate'.
Notice the characteristics of this rule. For example, the Antecedent connective is AND (Minimum), the Degree of support is 1, and the Consequent implication is Product.
Continue exploring the fuzzy system in the Fuzzy System Designer. When you are familiar with the system, you can click the Close button to exit the Fuzzy System Designer.
