Buildings.Controls.OBC.Utilities.PIDWithAutotuning.SystemIdentification.FirstOrderTimeDelay
Package with components related to a first-order plus time-delay model
Information
This package contains the blocks to identify the parameters of a first-order plus time-delay model.
Package Content
| Name | Description |
|---|---|
 ControlProcessModel
|
Identify the parameters of a first-order plus time-delay (FOPTD) model of the control process |
 Validation
|
Collection of models that validate the blocks in the FirstOrderTimeDelay |
 BaseClasses
|
Package with base classes |
Buildings.Controls.OBC.Utilities.PIDWithAutotuning.SystemIdentification.FirstOrderTimeDelay.ControlProcessModel
Identify the parameters of a first-order plus time-delay (FOPTD) model of the control process
Information
This block calculates the model parameters of a FOPTD model. Specifically, it employs Buildings.Controls.OBC.Utilities.PIDWithAutotuning.SystemIdentification.FirstOrderTimeDelay.BaseClasses.Gain and Buildings.Controls.OBC.Utilities.PIDWithAutotuning.SystemIdentification.FirstOrderTimeDelay.BaseClasses.TimeConstantDelay to identify the gain, the time constant, and the time delay, respectively.
The calculations are disabled by default. They will be enabled once the tuning period starts,
i.e., triSta becomes true.
The calculations complete when the tuning period ends,
i.e., triEnd becomes true.
Refer to
Buildings.Controls.OBC.Utilities.PIDWithAutotuning.Relay.Controller for detailed explanation
of the parameters yHig, yLow, and deaBan.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | yHig | Higher value for the output | |
| Real | yLow | Lower value for the output | |
| Real | deaBan | Deadband for holding the output value |
Connectors
| Type | Name | Description |
|---|---|---|
| input RealInput | tOn | Length for the on period [s] |
| input RealInput | tOff | Length for the off period [s] |
| input RealInput | tau | Normalized time delay [s] |
| input RealInput | u | Output of a relay controller |
| input BooleanInput | triSta | Relay tuning status, true if the tuning starts |
| input BooleanInput | triEnd | Relay tuning status, true if the tuning ends |
| input BooleanInput | inTun | Check if a tuning is ongoing |
| output RealOutput | k | Gain |
| output RealOutput | T | Time constant [s] |
| output RealOutput | L | Time delay [s] |
| output BooleanOutput | tunSta | True when the autotuning completes successfully |
Modelica definition
block ControlProcessModel
"Identify the parameters of a first-order plus time-delay (FOPTD) model of the control process"
parameter Real yHig(min=1E-6)
"Higher value for the output";
parameter Real yLow(min=1E-6)
"Lower value for the output";
parameter Real deaBan(min=1E-6)
"Deadband for holding the output value";
Buildings.Controls.OBC.CDL.Interfaces.RealInput tOn(
final quantity="Time",
final unit="s",
min=100*Buildings.Controls.OBC.CDL.Constants.eps)
"Length for the on period";
Buildings.Controls.OBC.CDL.Interfaces.RealInput tOff(
final quantity="Time",
final unit="s",
min=100*Buildings.Controls.OBC.CDL.Constants.eps)
"Length for the off period";
Buildings.Controls.OBC.CDL.Interfaces.RealInput tau(
final quantity="Time",
final unit="s",
min=100*Buildings.Controls.OBC.CDL.Constants.eps)
"Normalized time delay";
Buildings.Controls.OBC.CDL.Interfaces.RealInput u
"Output of a relay controller";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput triSta
"Relay tuning status, true if the tuning starts";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput triEnd
"Relay tuning status, true if the tuning ends";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput inTun
"Check if a tuning is ongoing";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput k
"Gain";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput T(
final quantity="Time",
final unit="s",
min=100*Buildings.Controls.OBC.CDL.Constants.eps)
"Time constant";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput L(
final quantity="Time",
final unit="s",
min=100*Buildings.Controls.OBC.CDL.Constants.eps)
"Time delay";
Buildings.Controls.OBC.CDL.Interfaces.BooleanOutput tunSta
"True when the autotuning completes successfully";
protected
Buildings.Controls.OBC.CDL.Reals.AddParameter addPar(
final p=1)
"Block that calculates the difference between 1 and the normalized time delay";
Buildings.Controls.OBC.CDL.Reals.Divide div
"The output of samtau divided by that of addPar";
Buildings.Controls.OBC.Utilities.PIDWithAutotuning.SystemIdentification.FirstOrderTimeDelay.BaseClasses.Gain
gain(final yHig=yHig, final yLow=yLow) "Block that calculates the gain";
Buildings.Controls.OBC.Utilities.PIDWithAutotuning.SystemIdentification.FirstOrderTimeDelay.BaseClasses.TimeConstantDelay
timConDel(
final yHig=yHig,
final yLow=yLow,
final deaBan=deaBan)
"Block that calculate the time constant and the time delay";
Buildings.Controls.OBC.CDL.Discrete.TriggeredSampler samK(
final y_start=1)
"Block that samples the gain when the tuning period ends";
Buildings.Controls.OBC.CDL.Discrete.TriggeredSampler samL(
final y_start=1)
"Block that samples the time delay when the tuning period ends";
Buildings.Controls.OBC.CDL.Discrete.TriggeredSampler samtOn(
final y_start=1)
"Block that samples the length of the on period when the tuning period ends";
Buildings.Controls.OBC.CDL.Discrete.TriggeredSampler samT(
final y_start=1)
"Block that samples the time constant when the tuning period ends";
Buildings.Controls.OBC.CDL.Discrete.TriggeredSampler samTau(
final y_start=0.5)
"Block that samples the normalized time delay when the tuning period ends";
Buildings.Controls.OBC.CDL.Reals.MultiplyByParameter gai(
final k=-1)
"Product of the normalized time delay and -1";
Buildings.Controls.OBC.CDL.Logical.Not not1
"Check if an error occurs during the autotuning process";
Buildings.Controls.OBC.CDL.Logical.And and2
"Check if the autotuning completes successfully";
Buildings.Controls.OBC.CDL.Utilities.Assert assTunFai(final message=
"Autotuning failed. The controller gains are unchanged.")
"Warning message when an autotuning fails";
CDL.Logical.Nand nand1 "Check if an errors occured during tuning";
equation
connect(gain.u, u);
connect(gain.tOn, tOn);
connect(gain.tOff, tOff);
connect(gain.triSta, triSta);
connect(timConDel.T, samT.u);
connect(samT.y, T);
connect(samT.trigger, triEnd);
connect(L, samL.y);
connect(samL.u, timConDel.L);
connect(samL.trigger, triEnd);
connect(samK.y, timConDel.k);
connect(samK.trigger, triEnd);
connect(samK.y, k);
connect(timConDel.tOn, samtOn.y);
connect(samtOn.u, tOn);
connect(samtOn.trigger, triEnd);
connect(gai.y, addPar.u);
connect(tau,samTau. u);
connect(samTau.y, gai.u);
connect(samTau.y, div.u1);
connect(triEnd,samTau. trigger);
connect(addPar.y, div.u2);
connect(div.y, timConDel.rat);
connect(and2.u1, not1.y);
connect(and2.y, tunSta);
connect(and2.u2, triEnd);
connect(timConDel.triFai, not1.u);
connect(gain.k,samK. u);
connect(nand1.u1, inTun);
connect(nand1.u2, timConDel.triFai);
connect(nand1.y, assTunFai.u);
end ControlProcessModel;