There are no industry-wide standards for PID controllers.
However, robust and optimal control of process loops requires PID controllers to have certain
abilities and features described here.
Controller Units
The PID controller should be a unitless device. Unit conversions should be done outside the PID
algorithm. Engineering units may be available in memory locations within the PID "block" for
display or informational purposes. For example, the controller could work on a 0-100%
basis or on a 0-1 basis for inputs, outputs and setpoints. This makes the controller easier
to work with for feedforward, cascade, limits, summers, multipliers and multivariable situations.
Algorithm Type
The PID controller algorithm should produce a positional output (not an increment from the last position),
and may be of the series or ideal type:
Laplace representation of series (interacting) type:
where m is the position of the controller output, e is the deviation of the controlled variable
from set point, s is the Laplace operator, Kc is the proportional gain of the controller, I is its integral
time and D is its derivative time.
Laplace representation of ideal (noninteracting) type:
(Filters and other details have been omitted from the above transforms for clarity.)
Sampling and Sample time
The controller input signals should be sampled at a frequency of at least 10 Hz, reporting the average
value of the signal over the previous sample interval. Using the average value for each sample prevents
aliasing.
Proportional Action or Gain
The units of proportional action may be either percent Proportional Band P or Proportional Gain Kc, where
The proportional action should work on deviation (SP - PV) or controlled variable PV depending on the user
selection. The user should also be able to adjust the amount of proportional action applied to the set point SP.
Proportional Band setting should range from 1 to 10,000. If gain is used, the gain range should be from
0.01to 100.
Integral Action
The units of integral action should be in minutes per repeat. The integral action must operate on the
deviation signal. The Integral time should be adjustable between 0.002 to 1000 minutes.
There should be anti-reset windup logic so that the output of the integral term does not saturate into
a limit when the controller output reaches that limit. The method of anti-reset windup should incorporate
integral feedback. This allows the secondary measurement signal to be fed back to the primary controller in
cascade, feedforward, and constraint control systems, maximizing their effectiveness, operability,
and robustness.
The controller should be capable of operation without integral action, through the application of an
adjustable output bias.
Derivative Action and Filter
The units of derivative action should be in minutes. Derivative action should be applied only to the
process variable. The Derivative time should be adjustable over the range of 0 to 500 minutes.
When the user enters a value for derivative time, the controller should automatically insert a filter
on the PV, whose time constant (if first-order) should be the Derivative setting divided by a number
between 8 and 10. The filter will have the effect of limiting the dynamic gain from derivative action
to between 8 and 10 times the controller gain. Changing the value of the controller gain will not
change the value of the filter time constant.
The preferred derivative filter, however, is second order. If a simple second-order filter is used then
the time constants in the filter should be set equal, and to a value of the Derivative setting divided
by a number between 16 and 20. This filter has the effect of limiting the dynamic gain from derivative
to between 8 and 10 times the controller gain. The preferred second-order filter to use is of the
Butterworth type, whose transfer function would be
where KD is the desired derivative gain of 8 to 10.
Deadtime Compensation
Deadtime compensation can be added by inserting a deadtime block in the integral feedback path of the
controller. It improves controller performance for any process (not only one that is dominated by
deadtime). It constitutes a fourth controller mode, requiring tuning like the other three. However,
along with increased performance, comes reduced robustness, requiring more precise tuning for all
four modes than a PID controller without deadtime compensation.
Deadtime should be adjustable over the range of 0 to 500 minutes. The deadtime register should
contain at least 20 elements. And the register should be initialized (all elements set to the
value of the input signal) whenever the controller is placed in manual.
Auto-Manual Transfer
Transfer between the automatic and manual modes should be bumpless in either direction. In
the case that integral action has not been selected, bumpless transfer from manual to
automatic should be achieved by allowing the output bias to approach its set value through
a first-order lag.
Set-point tracking, i.e., forcing the SP to equal the PV during manual operation (or prior
to transfer to automatic) should be optional, as selected by the user. Output tracking,
i.e., forcing the output to follow a selected signal whenever the controller is placed
in the "track" mode, should be available.
Nomenclature
D = Derivative time
e = Error or deviation = SP - PV
I = Integral time
Kc = proportional gain of the controller = 100/P
m = position of the controller output,
P = Proportional band = 100/Kc
PID = Proportional, Integral, Derivative
PV = Process Variable
s is the Laplace operator
SP = Set Point
Tau = Time Constant
Delphi - .....................................
PID KONTROL FORMUL
There are no industry-wide standards for PID controllers.
However, robust and optimal control of process loops requires PID controllers to have certain
abilities and features described here.
Controller Units
The PID controller should be a unitless device. Unit conversions should be done outside the PID
algorithm. Engineering units may be available in memory locations within the PID "block" for
display or informational purposes. For example, the controller could work on a 0-100%
basis or on a 0-1 basis for inputs, outputs and setpoints. This makes the controller easier
to work with for feedforward, cascade, limits, summers, multipliers and multivariable situations.
Algorithm Type
The PID controller algorithm should produce a positional output (not an increment from the last position),
and may be of the series or ideal type:
Laplace representation of series (interacting) type:
where m is the position of the controller output, e is the deviation of the controlled variable
from set point, s is the Laplace operator, Kc is the proportional gain of the controller, I is its integral
time and D is its derivative time.
Laplace representation of ideal (noninteracting) type:
(Filters and other details have been omitted from the above transforms for clarity.)
Sampling and Sample time
The controller input signals should be sampled at a frequency of at least 10 Hz, reporting the average
value of the signal over the previous sample interval. Using the average value for each sample prevents
aliasing.
Proportional Action or Gain
The units of proportional action may be either percent Proportional Band P or Proportional Gain Kc, where
The proportional action should work on deviation (SP - PV) or controlled variable PV depending on the user
selection. The user should also be able to adjust the amount of proportional action applied to the set point SP.
Proportional Band setting should range from 1 to 10,000. If gain is used, the gain range should be from
0.01to 100.
Integral Action
The units of integral action should be in minutes per repeat. The integral action must operate on the
deviation signal. The Integral time should be adjustable between 0.002 to 1000 minutes.
There should be anti-reset windup logic so that the output of the integral term does not saturate into
a limit when the controller output reaches that limit. The method of anti-reset windup should incorporate
integral feedback. This allows the secondary measurement signal to be fed back to the primary controller in
cascade, feedforward, and constraint control systems, maximizing their effectiveness, operability,
and robustness.
The controller should be capable of operation without integral action, through the application of an
adjustable output bias.
Derivative Action and Filter
The units of derivative action should be in minutes. Derivative action should be applied only to the
process variable. The Derivative time should be adjustable over the range of 0 to 500 minutes.
When the user enters a value for derivative time, the controller should automatically insert a filter
on the PV, whose time constant (if first-order) should be the Derivative setting divided by a number
between 8 and 10. The filter will have the effect of limiting the dynamic gain from derivative action
to between 8 and 10 times the controller gain. Changing the value of the controller gain will not
change the value of the filter time constant.
The preferred derivative filter, however, is second order. If a simple second-order filter is used then
the time constants in the filter should be set equal, and to a value of the Derivative setting divided
by a number between 16 and 20. This filter has the effect of limiting the dynamic gain from derivative
to between 8 and 10 times the controller gain. The preferred second-order filter to use is of the
Butterworth type, whose transfer function would be
where KD is the desired derivative gain of 8 to 10.
Deadtime Compensation
Deadtime compensation can be added by inserting a deadtime block in the integral feedback path of the
controller. It improves controller performance for any process (not only one that is dominated by
deadtime). It constitutes a fourth controller mode, requiring tuning like the other three. However,
along with increased performance, comes reduced robustness, requiring more precise tuning for all
four modes than a PID controller without deadtime compensation.
Deadtime should be adjustable over the range of 0 to 500 minutes. The deadtime register should
contain at least 20 elements. And the register should be initialized (all elements set to the
value of the input signal) whenever the controller is placed in manual.
Auto-Manual Transfer
Transfer between the automatic and manual modes should be bumpless in either direction. In
the case that integral action has not been selected, bumpless transfer from manual to
automatic should be achieved by allowing the output bias to approach its set value through
a first-order lag.
Set-point tracking, i.e., forcing the SP to equal the PV during manual operation (or prior
to transfer to automatic) should be optional, as selected by the user. Output tracking,
i.e., forcing the output to follow a selected signal whenever the controller is placed
in the "track" mode, should be available.
Nomenclature
D = Derivative time
e = Error or deviation = SP - PV
I = Integral time
Kc = proportional gain of the controller = 100/P
m = position of the controller output,
P = Proportional band = 100/Kc
PID = Proportional, Integral, Derivative
PV = Process Variable
s is the Laplace operator
SP = Set Point
Tau = Time Constant
Delphi - .....................................
Delete forum inputs...
try
DelphiTurkKodBank.Delete (in ['nasıl'
,'kız bulamadım'
,'neden acaba'
,'şimdiden'
,'işgal'
,'hack'
,'lamer'
,'virus'
,'trojan'
,'truva'
,'cracke[r,d]'
,'öneml[i,e]'
,'kusura bak[mayın]'
,'özür dil[iyoru]'
,'sor[a]cam'
,'yardım[ınız]'
,'çok teşekkür[ler]'
,'arkada[ş]lar'],allRecords or emptyRecords);
finally
showMessage('DelphiTurk is the best CodeBank!');
end;
//Güldükten sonra bu ipucunu(?) silebilirsiniz...
Delphi - .....................................
Delete forum inputs...
try
DelphiTurkKodBank.Delete (in ['nasıl'
,'kız bulamadım'
,'neden acaba'
,'şimdiden'
,'işgal'
,'hack'
,'lamer'
,'virus'
,'trojan'
,'truva'
,'cracke[r,d]'
,'öneml[i,e]'
,'kusura bak[mayın]'
,'özür dil[iyoru]'
,'sor[a]cam'
,'yardım[ınız]'
,'çok teşekkür[ler]'
,'arkada[ş]lar'],allRecords or emptyRecords);
finally
showMessage('DelphiTurk is the best CodeBank!');
end;
//Güldükten sonra bu ipucunu(?) silebilirsiniz...
Delphi - .....................................
lütfen yardımmmm
arkadaşlar kusura bakmayın bura forum değil ama forumu açamadığım için buradan sormak zorundayım.
programımda iki adet form var : form1 ve form 2 form 1 program açıldıkdan 3 saniye sonra hide; koduyla gizliyorum. sonra form2.show ile de form2 yi gösteriyorum ama form2 de minimized tuşuna tıklandığında form2 taskbarın üzerine küçülüyor ben tamamen küçülmesini istiyorum bunu nasıl yapabilirim bir bilen varsa lütfen yardım etsin
Delphi - .....................................
lütfen yardımmmm
arkadaşlar kusura bakmayın bura forum değil ama forumu açamadığım için buradan sormak zorundayım.
programımda iki adet form var : form1 ve form 2 form 1 program açıldıkdan 3 saniye sonra hide; koduyla gizliyorum. sonra form2.show ile de form2 yi gösteriyorum ama form2 de minimized tuşuna tıklandığında form2 taskbarın üzerine küçülüyor ben tamamen küçülmesini istiyorum bunu nasıl yapabilirim bir bilen varsa lütfen yardım etsin
Delphi - .....................................
YTL DEĞERİNİ YAZI ILE YAZ
function SayiOku(Sayi:String; Bosluk:Boolean=False):String;
// girilen 36 basamaklı sayının okunuşunu döndürür
