#*-------------------------------------------------------------------
* 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