source: branches/gui/eml/controllers/pi.mso @ 558

using "types";
        
Model PI_simple
ATTRIBUTES
        Pallete         = true;
        Icon            = "icon/PID"; 

        PARAMETERS
        Kp         as Real (Brief="Controller gain", Default=0.5);
        Ki         as Real (Brief="Integral time constant", Unit='s');
        bias       as Real (Brief="Previous scaled bias",Default=0.5);

        MinInput   as control_signal(Default=-1000);
        MaxInput   as control_signal(Default=1000);
        
        VARIABLES
        SetPoint   as Real               (Brief="Scaled setPoint", Lower=0, Upper=1, Default=0.5);
in      Input      as control_signal (Brief="Previous scaled input signal", Default=0.5, PosX=0, PosY=0.5);
out     Output     as control_signal (Brief="Scaled output signal", Default=0, PosX=1, PosY=0.5);

        input      as Real     (Brief="Scaled input variable", Hidden=true);
        setPoint           as Real     (Brief="Scaled set point", Hidden=true);
        intTerm    as Real               (Brief="Integral term", Default=0, Protected=true);
        outps      as Real           (Brief="Variable outp scaled between 0 and 1", Protected=true);
        
        EQUATIONS
        "Calculate integral term"
        Ki*diff(intTerm) = setPoint - input;
        
        "Sum of proportional, integral and derivative terms"
        outps = bias + Kp*(setPoint - input) + intTerm;
        
        input*(MaxInput-MinInput) = Input-MinInput;
        setPoint*(MaxInput-MinInput) = SetPoint-MinInput;


        if outps > 1 then
                Output = 1;
        else
                if outps < 0 then
                        Output = 0;
                else
                        Output = outps;
                end
        end

        INITIAL
        intTerm = 0;
end

Model PI
ATTRIBUTES
        Pallete         = true;
        Icon            = "icon/PID"; 

        PARAMETERS
        bias       as positive (Brief="Previous scaled bias", Lower=0, Upper=1, Default=0.5);
        beta       as positive (Brief="Proportional term setPoint change filter", Default=1);
        Action     as Switcher (Brief="Controller action", Valid=["Direct","Reverse"], Default = "Reverse");
        
        MinInput   as control_signal(Default=-1000);
        MaxInput   as control_signal(Default=1000);

        gain       as positive           (Brief="Controller gain", Lower=0, Upper=1, Default=0.5);
        intTime    as Real               (Brief="Integral time constant", Unit='s');
    autoMan    as Real                   (Brief="Controller option: (0) Automatic, (1) Manual");    

        VARIABLES
        SetPoint   as Real               (Brief="Scaled setPoint", Lower=0, Upper=1, Default=0.5);
in      Input      as control_signal (Brief="Previous scaled input signal", Default=0.5, PosX=0, PosY=0.5);
out     Output     as control_signal (Brief="Scaled output signal", Default=0, PosX=1, PosY=0.5);
        
        propTerm   as Real               (Brief="Proportional term", Default=0);
        intTerm    as Real               (Brief="Integral term", Default=0);
        input      as Real     (Brief="Scaled input variable", Hidden=true);
        setPoint           as Real     (Brief="Scaled set point", Hidden=true);
        action     as Real     (Brief="Controller action: (-1) Direct,(1) Reverse", Default=-1, Hidden=true);
        outp       as control_signal (Brief="Sum of proportional, integral and derivative terms");
        error      as Real               (Brief="Error definition for proportional term");
        outps      as Real           (Brief="Variable outp scaled between -1 and 1");
        
        EQUATIONS
        
        input*(MaxInput-MinInput) = Input-MinInput;
        setPoint*(MaxInput-MinInput) = SetPoint-MinInput;

        if autoMan equal 0 then 
                "Error definition"      
                error = beta*setPoint - input;
        else
                "Error definition"
                error = input*(beta-1.0);
        end

        switch Action
        case "Direct":
                action = -1.0;
        case "Reverse":
                action = 1.0;
        end

        "Calculate proportional term"
        propTerm=error;
        
        "Scale outp" 
        #outps=2*outp-1;
        outps=outp;
        
        if outps > 1 then
                Output = 1;
        else
                if outps < -1 then
                        Output = -1;
                else
                        Output = outps;
                end
        end
                
        "Calculate integral term"
        intTime*diff(intTerm) = setPoint - input;
        
        "Sum of proportional, integral and derivative terms"
        outp = bias + action*gain*(propTerm + intTerm);

        INITIAL
        intTerm = 0;    
end