modelController

Partial interface for a generic controller

Information

Description

Partial interface for a continuous/discrete time controller.
The model has the following ports

Name	Description	Conditional?
SP	Set Point	NO
PV	Process Variable	NO
CS	Control Signal	NO
TR	Track Reference signal	YES (useTS)
TS	Track Switch signal	YES (useTS)
Bias	Biasing signal	YES (useBIAS)
ATreq	AutoTuning request	YES (useAT)

And some of them can be conditionally selected, by specifying a boolean flag.

AntiWindUp mode

If the boolean flag AntiWindup is tue the output of the block ( CS ) saturates at the values specified by CSmin and CSmax.

Tracking mode

If the boolean flag useTS, the inputs TS and TR are enabled.
When enabled, if the TS signal is true the output CS is forced to follow the track reference signal TR.

Discretisation

For each controller is defined a sampling time Ts and a coefficient alpha.
The discretisation of the continuos time transfer function has been performed with the bilinear transformation formula

                 z - 1 
  s = ------------------------------
        z*alpha*Ts - (alpha - 1)*Ts

that is equivalent to

Forward Euler (FE) if
```
alpha = 0
```
Backward Euler (BE) if
```
alpha = 1
```
Tustin (TU) if
```
alpha = 0.5
```

Parameters

Type	Name	Default	Description
Real	eps	1e-1	small time constant that represents the time for switching between auto and tracking mode
Boolean	useTS	false	=true, if TS and TR inputs are enabled
Boolean	useBIAS	false	=true, if BIAS input is enabled
Boolean	useAT	false	=true, if AutoTuning input is enabled
Boolean	useGS	false	=true, if GainScheduling inputs are enabled
Boolean	useSAT	false	=true, if Saturation outputs are enabled
Discretisation
Real	Ts	0	Sampling time (if <= 0 continuous time)
IndustrialControlSystems.LinearSystems.Discrete.Types.discrMethod	method	IndustrialControlSystems.LinearSystems.Discrete.Types.discrMethod.BE	Discretisation method
Saturation
Boolean	AntiWindup	false	Flag that enables the antiwindup feature
Real	CSmin	0	minimum value of the CS
Real	CSmax	1	maximum value of the CS
Initialisation
Real	CS_start	0	output initial value

Connectors

Type	Name	Description
Modelica.Blocks.Interfaces.RealInput	TR	Track Reference signal
Modelica.Blocks.Interfaces.BooleanInput	TS	Track Switch signal
Modelica.Blocks.Interfaces.RealInput	BIAS	Bias
Modelica.Blocks.Interfaces.RealInput	SP	Set Point signal
Modelica.Blocks.Interfaces.RealOutput	CS	Control signal
Modelica.Blocks.Interfaces.RealInput	PV	Process Variable signal
Modelica.Blocks.Interfaces.BooleanInput	ATreq	Auto Tuning request
Modelica.Blocks.Interfaces.BooleanOutput	satHI
Modelica.Blocks.Interfaces.BooleanOutput	satLOW

Components

Type	Name	Description
Real	bias	bias signal
Real	tr	track reference value
Boolean	ts	track reference signal
Boolean	at_req	auto tuning enabling signal
Boolean	satHigh	High saturation signal
Boolean	satLow	Low saturation signal

Revisions

Industrial Control Systems (v 1.0.0) : April-May 2012