Changing a continuous variable to fuzzy with RTES

Variables

Analog Input : PRESS

Registers : PRESS_SP, PNORMAL, PLOW, PHIGH, PVLOW, PVHIGH

Rules

RULE PVHIGH=PRESS>(1.3*PRESS_SP)
RULE PVLOW=PRESS<(0.7*PRESS_SP)
RULE PHIGH=PVHIGH’&(PRESS>(1.15*PRESS_SP))
RULE PLOW=PVLOW’&(PRESS<(0.85*PRESS_SP))
RULE PNORMAL=(PVHIGH!PHIGH!PLOW!PVLOW)’

Notes

Rather than considering the current value of PRESS, the 5 new mutually exclusive binary (true or false) variables inform you – and the system – about the status of PRESS, ie : normal, low, very low, high or very high.

The factors used and PRESS_SP may be refined to take into account other situations. The boundaries may depend on the process, the time, the season, etc. More boundaries may be added to implement other terms such "moderately high", "very very low", etc