source: branches/gui/eml/controllers/PIDIncr.mso @ 609

#*-------------------------------------------------------------------
* EMSO Model Library (EML) Copyright (C) 2004 - 2007 ALSOC.
*
* This LIBRARY is free software; you can distribute it and/or modify
* it under the therms of the ALSOC FREE LICENSE as available at
* http://www.enq.ufrgs.br/alsoc.
*
* EMSO Copyright (C) 2004 - 2007 ALSOC, original code
* from http://www.rps.eng.br Copyright (C) 2002-2004.
* All rights reserved.
*
* EMSO is distributed under the therms of the ALSOC LICENSE as
* available at http://www.enq.ufrgs.br/alsoc.
*--------------------------------------------------------------------
* Author: Tiago Osório
* $Id: PIDIncr.mso 560 2008-07-23 17:13:20Z rafael $
*-------------------------------------------------------------------*#
using "types";

Model MPorts

ATTRIBUTES
        Pallete         = false;
        Brief           = "Model of Ports to be used with incremental PIDs.";
        
        VARIABLES
        
        input      as control_signal (Brief="Previous scaled input signal", Default=0.5);
        output    as control_signal (Brief="Scaled output signal", Default=0.5);
        setPoint   as control_signal (Brief="Scaled setPoint",Default=0.5);

end

Model MInternal_Variables
        
        ATTRIBUTES
        Pallete         = false;
        Brief           = "Model of Internal Variables to be used with incremental PIDs.";
        
        VARIABLES

        dderivTerm    as control_signal (Brief="Derivative term",Unit='1/s', Default=0);
        dFilt         as control_signal (Brief="Derivative term filtered", Default=0.5,Unit='1/s');
        error         as control_signal (Brief="Error definition for proportional term",Unit='1/s');
        errorD        as control_signal (Brief="Error definition for derivative term",Unit='1/s');
        errorI        as control_signal (Brief="Error definition for integral term");
        inputFilt     as control_signal (Brief="Filtered input");
        dintTerm      as control_signal (Brief="Integral term", Default=0,Unit='1/s');
        doutp         as control_signal (Brief="Sum of proportional, integral and derivative terms",Unit='1/s');
        outps         as control_signal (Brief="Variable outp scaled between -1 and 1");
        outp          as control_signal (Brief="Variable outp");
        dpropTerm     as control_signal (Brief="Proportional term", Default=0,Unit='1/s');
        setPointFilt  as control_signal (Brief="Filtered setPoint", Default=0);

end

Model PIDIncr

ATTRIBUTES
        Pallete         = true;
        Icon            = "icon/PIDIncr"; 
        Brief           = "Model of incremental PIDs.";
        Info            =
"== Inputs ==
* scaled processs variable.
* scaled bias.
* scaled setpoint.

== Outputs ==
* a scaled output.
";
        
        PARAMETERS
        
        PID_Select as Switcher (Brief="Type of PID Incremental", Valid=["Ideal","Parallel","Series","Ideal_AWBT","Parallel_AWBT","Series_AWBT","Ideal_AW","Parallel_AW","Series_AW"], Default = "Ideal");
        Action     as Switcher (Brief="Controller action", Valid=["Direct","Reverse"], Default = "Reverse");
        Mode       as Switcher (Brief="Controller mode", Valid=["Automatic","Manual"], Default = "Automatic");
        Clip       as Switcher (Brief="Controller mode", Valid=["Clipped","Unclipped"], Default = "Clipped");
        
        alpha      as positive (Brief="Derivative term filter constant", Default=1);
        beta       as positive (Brief="Proportional term setPoint change filter");
        bias       as control_signal (Brief="Previous scaled bias", Default=0.5);
        derivTime  as time_sec (Brief="Derivative time constant");
        intTime    as time_sec (Brief="Integral time constant");
        gain       as positive (Brief="Controller gain", Default=0.5);
        gamma      as positive (Brief="Derivative term SP change filter");
        tau        as time_sec (Brief="Input filter time constant");
        tauSet     as time_sec (Brief="Input filter time constant");
        
        VARIABLES
        Internal           as MInternal_Variables;
        Ports              as MPorts;
        AWFactor     as Real(Brief="Integral term multiplier used in anti-reset windup", Hidden=true);
        action       as Real(Hidden=true);
        
        EQUATIONS

        if (tau < 1e-6) then
                "Input first order filter"
                (tau + 1e-3*'s')*diff(Internal.inputFilt)= Ports.input - Internal.inputFilt;
        else
                "Input first order filter"
                tau*diff(Internal.inputFilt)= Ports.input - Internal.inputFilt; 
        end

        if (tauSet < 1e-6) then
                "setPoint first order filter"
                (tauSet + 1e-3*'s')*diff(Internal.setPointFilt)= Ports.setPoint - Internal.setPointFilt;
        else
                "setPoint first order filter"
                tauSet*diff(Internal.setPointFilt)= Ports.setPoint - Internal.setPointFilt;
        end

        switch Mode
        case "Manual":
                "Error definition for proportional term"
                Internal.error*'s' = Internal.inputFilt*(beta-1.0);
                "Error definition for derivative term"
                Internal.errorD*'s'= Internal.inputFilt*(gamma-1.0);
                "Error definition for integral term"            
                Internal.errorI= 0;
        case "Automatic":
                "Error definition for proportional term"                        
                Internal.error = beta*diff(Internal.setPointFilt) - diff(Internal.inputFilt);
                "Error definition for derivative term"
                Internal.errorD = gamma*diff(Internal.setPointFilt) - diff(Internal.inputFilt);
                "Error definition for integral term"
                Internal.errorI = Internal.setPointFilt-Internal.inputFilt;     
        end
        
        "Calculate proportional term"
        Internal.dpropTerm=Internal.error;  
        
        if (derivTime equal 0) then
                "Derivative term filter"        
                alpha*(derivTime + 1e-3*'s')*diff(Internal.dFilt) = Internal.errorD - Internal.dFilt;
        else
                "Derivative term filter"        
                alpha*(derivTime)*diff(Internal.dFilt) = Internal.errorD - Internal.dFilt;
        end

        "Calculate derivative term"
        Internal.dderivTerm = derivTime*diff(Internal.dFilt);
        
    "Unscaled output"
        diff(Internal.outp)=Internal.doutp;

        "Scale outp"
        Internal.outps=2*Internal.outp-1;

        switch Clip
        case "Clipped":
                #if abs(Internal.outps)>1 then
                #       "Calculate clipped output when it's saturated"
                #       Ports.output=(sign(Internal.outps)*1+1)/2;
                #else
                #       "Calculate clipped output when it's not saturated"
                #       Ports.output=Internal.outps;
                #end
                Ports.output = max([0, Internal.outp]);
        case "Unclipped":
                "Calculate unclipped output"
                Ports.output=Internal.outp;
        end
        
        switch Action
        case "Direct":
                action = -1.0;
        case "Reverse":
                action = 1.0;
        end

switch PID_Select
        
case "Ideal":
        
        "Calculate integral term"
        intTime*Internal.dintTerm = Internal.errorI;
        
        "Sum of proportional, integral and derivative terms"
        Internal.doutp = action*gain*(Internal.dpropTerm + Internal.dintTerm + Internal.dderivTerm);

        "Calculate AWFactor - Not in use in this mode"
        AWFactor=1;
        
case "Parallel":
        
        "Calculate integral term"
        intTime*Internal.dintTerm = Internal.errorI;    
        
        "Sum of proportional, integral and derivative terms"
        Internal.doutp = action*(gain*Internal.dpropTerm + Internal.dintTerm + Internal.dderivTerm);

"Calculate AWFactor - Not in use in this mode"
        AWFactor=1;
        
case "Series":
        
        "Calculate integral term"
        intTime*Internal.dintTerm = Internal.errorI;    
        
        "Sum of proportional, integral and derivative terms"
        Internal.doutp = action*(gain*(Internal.dpropTerm + Internal.dintTerm)*(1/'s' + Internal.dderivTerm)*'s');
        
        "Calculate AWFactor - Not in use in this mode"
        AWFactor=1;
        
case "Ideal_AWBT":
        
        "Calculate integral term with anti-windup and bumpless transfer"
        action*gain*(intTime*Internal.dintTerm-Internal.errorI) = Ports.output-Internal.outp;

        "Sum of proportional, integral and derivative terms"
        Internal.doutp = action*gain*(Internal.dpropTerm + Internal.dintTerm + Internal.dderivTerm);

        "Calculate AWFactor - Not in use in this mode"
        AWFactor=1;
        
case "Parallel_AWBT":
        
        "Calculate integral term with anti-windup and bumpless transfer"
        action*gain*(intTime*Internal.dintTerm-Internal.errorI) = Ports.output-Internal.outp;
        
        "Sum of proportional, integral and derivative terms"
        Internal.doutp = action*(gain*Internal.dpropTerm + Internal.dintTerm + Internal.dderivTerm);

"Calculate AWFactor - Not in use in this mode"
        AWFactor=1;

case "Series_AWBT":
        
        "Calculate integral term with anti-windup and bumpless transfer"
        action*gain*(intTime*Internal.dintTerm-Internal.errorI) = Ports.output-Internal.outp;

        "Sum of proportional, integral and derivative terms"
        Internal.doutp = action*(gain*(Internal.dpropTerm + Internal.dintTerm)*(1/'s' + Internal.dderivTerm)*'s');

"Calculate AWFactor - Not in use in this mode"
        AWFactor=1;
        
case "Ideal_AW":
        
        "Calculate integral term with anti-windup"
        intTime*Internal.dintTerm = AWFactor*Internal.errorI;
        
        "Sum of proportional, integral and derivative terms"
        Internal.doutp = action*gain*(Internal.dpropTerm + Internal.dintTerm + Internal.dderivTerm);
        
        if abs(Internal.outps)>1 and (action*sign(Internal.outps)*Internal.errorI)>0 then
                "Calculate AWFactor"
                AWFactor=-tanh(sign(Internal.outps)*Internal.outps*100-102);
        else
                "Calculate AWFactor"
                AWFactor=1;
        end

case "Parallel_AW":
        
        "Calculate integral term with anti-windup"
        intTime*Internal.dintTerm = AWFactor*Internal.errorI;
        
        "Sum of proportional, integral and derivative terms"
        Internal.doutp = action*(gain*Internal.dpropTerm + Internal.dintTerm + Internal.dderivTerm);
        
        if abs(Internal.outps)>1 and (action*sign(Internal.outps)*Internal.errorI)>0 then
                "Calculate AWFactor"
                AWFactor=-tanh(sign(Internal.outps)*Internal.outps*100-102);
        else
                "Calculate AWFactor"
                AWFactor=1;
        end

case "Series_AW":
        
        "Calculate integral term with anti-windup"
        intTime*Internal.dintTerm = AWFactor*Internal.errorI;
        
        "Sum of proportional, integral and derivative terms"
        Internal.doutp = action*(gain*(Internal.dpropTerm + Internal.dintTerm)*(1/'s' + Internal.dderivTerm)*'s');
        
        if abs(Internal.outps)>1 and (action*sign(Internal.outps)*Internal.errorI)>0 then
                "Calculate AWFactor"
                AWFactor=-tanh(sign(Internal.outps)*Internal.outps*100-102);
        else
                "Calculate AWFactor"
                AWFactor=1;
        end

end

        INITIAL
        Ports.output = bias;    
        diff(Internal.dFilt) = 0/'s^2';
        diff(Internal.inputFilt)=0/'s';
        diff(Internal.setPointFilt)=0/'s';
        
end