Omron E5ZD, Руководство по эксплуатации

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3-6 Fuzzy Control
The E5ZD-8F
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-E incorporates hybrid control that combines fuzzy-logic
control and PID with feed-forward circuitry. Hybrid control assures excellent re-
sponse characteristics for external disturbance.
3-6-1 Control Configuration
The PID with feed-forward (circuitry) and fuzzy control circuitry are connected to
each other in parallel. The PID circuitry is always active, while the fuzzy control
circuitry is active only when there is external disturbance. This means that the
control method is the same as that of other E5ZD Controllers when operation is
started or when operation is stable. When there is external disturbance, howev-
er, the fuzzy control circuitry is activated to respond to the external disturbance,
i.e., the E5ZD-8F
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-E adjusts overshooting and undershooting to ensure
stable operation.
3-6-2 Operating Principles
The total output of the E5ZD-8F
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-E consists of the output of the fuzzy
control circuitry and that of the PID with feed-forward circuitry. The fuzzy control
circuitry outputs a compensation according to the temperature deviation (exter-
nal disturbance) and the derivative of the deviation (i.e., the speed of the temper-
ature change) that are input to the fuzzy control circuitry. Judging from the tem-
perature deviation and the derivative of the deviation, the fuzzy control circuitry
increases or decreases the output of the PID with feed-forward circuitry.
Fuzzy control section
PID
Controlled
system
Deviation
Derivative of deviation
Derivative
Fuzzy control amount
Fuzzy control amount
Fuzzy logic
–
+
+
+
Turned on for disturbances
Deviation
Set
temperature
PID control amount
Control Section Block Diagram
Fuzzy Inputs and Output
Temperature
Output
variable
Fuzzy Control Output When the temperature is higher or lower than the set temperature, the fuzzy con-
trol circuitry will produce an output to return the temperature to the set value.
When the temperature approaches the set value, the fuzzy control circuitry will
have no output and only PID with feed-forward circuitry will control the tempera-
Fuzzy Control
Section 3-6