About The Pid Operation; Operation Method And Formula - Mitsubishi Q Series User Manual

1 GENERAL DESCRIPTION

1.3 About the PID Operation

1.3.1 Operation method and formula

SV(Set value)
Kp
: Proportional gain
Ti
: Integral time
T
: Derivative time
D
Fig. 1.5 Algorithm of PID control in measured value incomplete differentiation
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The Q62HLC can perform PID control in measured value incomplete differentiation.
The PID control in measured value incomplete differentiation is an operation method
which puts the first-order delay filter as the input for derivative control action, and
performs PID operation with the error value (E) after deleting the high-frequency noise
component.
(1) The algorithm of the PID control in measured value incomplete
differentiation is shown in Figure 1.5.
Control response
parameters
Slow
Normal control
Fast
: Derivative gain
s : Laplace transform conversion
(2) The formula used for Q62HLC is shown below:
MV = MV +
n n-1
+
: Sampling period
MV : Incomplete derivative output
PV : Measured value
T : Derivative time
D
1
: Derivative gain
Q62HLC
+
Kp(1+
-
T
D
(PV - PV ) -
n-1 n
T
T
D
Disturbance D
1
+
)
Ti s
MV
-
Kp T s
D
1+ T
D S
PV(Measured value)
MV
n-1
D
MELSEC-Q
Control object
G(s)
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