phytron
25
MA 1311-A001 EN
6.4 Description of the Control Algorithm
The following control algorithm has been digitally implemented in the PIDM01 software:
e
sum
= e
sum
+ e
y = K
p
x e + K
i
x T
a
x e
sum
+ K
d
x (e
– e
alt
) / T
a
e
alt
= e
e
Control deviation (in 1/10 degree)
e
sum
Sum of all previous control variances
e
alt
Previous value of e
y
Manipulated variable (PWM 0 to 100 %)
T
a
Sampling time (100 ms)
K
p
Gain factor proportional
K
i
Gain factor integral
K
d
Gain factor derivative
A scaling factor of 100 is stored for the i component and d component.
The algorithm changes as follows:
e
sum
= e
sum
+ e
y = K
p
x e + K
i
x T
a
x e
sum
/ 100 + K
d
x (e
– e
alt
) / T
a
/ 100
e
alt
= e
Control algorithm with temperature scaling (1/10 degree) and the sampling time
(T
a
= 0.1 s):
Sf scaling factor
i component
Sf
i
Ta / 100 = 0.001 (
1/
1000
)
d component
Sf
d
1 / Ta / 10 = 0.1 (
1
)
y = K
p
x e + K
i
/
1000
x e
sum
+ K
d
x (e
– e
alt
) /
1
