#*-------------------------------------------------------------------
* 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.
*
*----------------------------------------------------------------------
* Model Lead Lag
*-----------------------------------------------------------------------
* - Inputs
*		- a input signal
* 
* - Outputs
*		- a output signal
*
*
*-----------------------------------------------------------------------
* Author: Tiago Osório
* $Id: lead_lag.mso 74 2006-12-08 18:43:02Z paula $
*---------------------------------------------------------------------*#

using "types";
 
 
Model Lead_lag

	PARAMETERS
    gain  as positive (Brief="model gain");
	beta  as positive (Brief="lead time constant", Unit="s");
	alpha as positive (Brief="lag time constant", Unit="s");
	
	VARIABLES
	input  as Real (Brief="input signal");
	output as Real (Brief="output signal");
	aux    as Real (Brief="internal variable");
	
	EQUATIONS
	
	"Calculate variable aux"
	alpha*diff(aux)=gain*input-aux;
	
	"Calculate output"
	output=beta*diff(aux) + aux;

	INITIAL
	diff(aux)= 0 * "1/s";
	
end