Chino KP 2000 Series, Instructions Manual

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10-5. PID control
PID is the most generic control algorithm that consists of three operations namely P (Proportion), I
(Integration) and D (Differentiation).
①
P operation
・
It is the basic operation of PID control. It largely affects the responsiveness and the stability. Offset occurs
only in proportion operation.
・
If P is increased, the amplitude of PV (measurement value) becomes less and the stability improves
however the responsiveness deteriorates.
・
By setting P=0% two-position control action takes place.
② Ｉ
operation
・
Offset due to P operation can be eliminated however as the phase is delayed stability deteriorates.
・
If I is reduced (integral operation is strengthened), responsiveness improves, over shoot increases.
・
Setting value '0' is equivalent to
∞
(infinity).
③
D operation
・
It compensates the time that is wasted and delay in phase due to delayed elements. However as gain in
high frequency area increases, there is a limit for the strength.
・ If D is increased, responsiveness increases for a large deviation, however for quick periodic deviations
stability deteriorates.
・ '0' of the settings value is equivalent to OFF.
・ The setting value of D, is 1/6
th
to 1/4
th
the setting value of I and it is generic.
Collectively the PID operation is as follows.
P (Proportion)
operation
Ｉ
(Integration)
operation
D (Differentiation)
operation
Input
Output
The controller has 2 types of PID control algorithms installed, either of it can be selected.
①
POSITION
・
Position type PID system.
・
Comparatively, response is valid for control target.
②
VELOCITY
・
Velocity type PID system.
・
Comparatively, response is valid for quick control target.
For theory and details of PID control see its special literature.