source: branches/gui/Block-Oriented EML/Control Systems/SecondOrderDynamics.mso

#*-------------------------------------------------------------------
* 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 is distributed under the terms of the ALSOC LICENSE as
* available at http://www.enq.ufrgs.br/alsoc.
*-----------------------------------------------------------------------
* Author: Jonathan Ospino
* $Id: SecondOrderDynamics.mso  2012$
*---------------------------------------------------------------------*#

using "types";
 
Model SOD
        
        ATTRIBUTES
        Pallete=true;
        Icon="icon/SOD";
        Info="== Second-Order Dynamics==
              
                  It takes an input variable and computes 
              the respective value of the output variable according
              to a Second-Order Dynamics (SOD).";
        
        PARAMETERS
        
        K as Real(Brief="Steady-state gain");
        Tau as time_sec(Brief="Characteristic time");
        Dseda as Real(Brief="Damping ratio");


        VARIABLES
        in In as Real(Brief="Input variable",Protected=true,PosX=0,PosY=0.5);
        W as Real(Brief="First derivative of Y",Hidden=true); 
        out Out as Real(Brief="Output variable",Protected=true,PosX=1,PosY=0.5);
        
        EQUATIONS

        "First-Order Dynamics (FOD)"
        (Tau^2)*diff(W)/'s'+(2*Tau*Dseda)*diff(Out)+Out=K*In;
        
        "First derivative of Ydev"
        W=diff(Out)*'s';
        
        INITIAL
        Out=0;
        W=0;
        
end