Omron E5ZD, Руководство по эксплуатации

Страница: 71 / 157

61
ture. If the temperature approaches the set value too quickly, the fuzzy control
circuitry will produce an output to prevent overshooting or undershooting.
ÉÉÉÉ
ÉÉÉÉ ÉÉÉÉ
Fuzzy control
output
ÉÉÉ
ÉÉÉ ÉÉÉÉ
ÉÉÉ
ÉÉÉ
Fuzzy control
output
Fuzzy Control Output with Slow Temperature Changes
Fuzzy Control Output with Rapid Temperature Changes
3-6-3 Application
The PID with feed-forward circuitry of the E5ZD-8F
j
-E is always activated,
while the fuzzy control circuitry is activated only when there is external distur-
bance. It is thus possible to adjust the PID parameters in the same way as for any
other E5ZD Controller.
To change the control waveform at startup or during stable operation, adjust the
PID parameters. When the PID parameters are adjusted, the parameters of the
fuzzy control circuitry will be modified automatically. To adjust the external dis-
turbance waveform, adjust the parameters of the fuzzy control circuitry. If the pa-
rameters of the fuzzy control circuitry are adjusted, only the external disturbance
waveform will change without influencing the control waveform when starting
operation or during stable operation.
Rise time
PID only
Stable
PID only
External disturbance
PID and fuzzy
Stable
PID only
Set value
Control Waveform vs. Fuzzy Control Circuitry
3-6-4 Fuzzy Parameters, Autotuning, PID Constants
Autotuning makes it possible to automatically set the parameters of the fuzzy
control circuitry just like PID parameters; the user does not need to worry about
the settings of parameters during normal operation.
Autotuning automatically sets the values of fuzzy scales 1 and 2 as well as the
PID parameters. The fuzzy strength, however, will not change. If the PID param-
eters have been manually changed, the values of fuzzy scales 1 and 2 will be
automatically set according to the PID parameters that have been changed: to
change the parameters of the fuzzy control circuitry manually, set the PID pa-
rameters first.
Fuzzy Control
Section 3-6