Rockwell Automation RSLogix 5000 Fuzzy Designer - Manual (Page 109)

Publication LOGIX-UM004A-EN-P - March 2007
FuzzyDesigner Projects 109
Operations with Rules
You can add, create, or delete rules.
Adding a Rule
To add a rule, click the first available blank row and a new rule with
the correct index will be created. Repeat this if you want to add more
rules.
Creating a Rule
With the Rule Editor, you can make or modify the rule base of the
selected Rule Block. Each rule has the following assigned to it:
• Index - the position of the rule in the rule base, usually greater
than zero
• Activity flag check box - if checked, the rule is enabled,
otherwise it is disabled
• DOF
An active rule is evaluated during the inference process and might
influence the fuzzy system output. Inactive rules remain in the
database but are not evaluated.
Temporarily enabling and disabling rules can help you fine-tune your
fuzzy system.
The rule specification contains the premise variables and weighted
consequent variables. The rule base columns in the Rule Editor are
arranged in the same order as the related variable links are applied.
If you want to create a rule, then use a mouse. Select the table cell
you want to modify and choose the required parameter. By clicking
on the cell with the rule activity, you can set the rule as active
(checked) or inactive (unchecked). When you click the cell of the
premise or consequent variable, choose the required term from the
visualized combo box. All relevant terms of the respective variables
are offered including their inverses. The rule base is the only place
where you can apply the fuzzy logic NOT operator. Inversed terms
are marked by NOT followed by the term name.
In the rule base table, the OR operator can also be used.
1. Select OR in the combo box, then check the terms that you want
to use in the OR expression (see OR Expression Editor).