At the time of writing Allen Bradley did not offer any Fuzzy Logic systems for their PLCs. But, other vendors such as Omron offer commercial controllers. Their controller has 8 inputs and 2 outputs. It will accept up to 128 rules that operate on sets defined with polygons with up to 7 points.
It is also possible to implement a fuzzy logic controller manually, possible in structured text.
• Fuzzy logic control control examples
slack adjuster in multi stage rolling press
boiler control - gas air rates with exhaust O2 sensor
prediction of cutting tool failure
mixing ingredients with variable properties, e.g., juice
bottle filling machine
pultrusion machine control
powder/fiber metering system
speed control for paint/adhesive application
power efficiency controls for greenhouse
waste water treatment
weld speed control
layer thickness control