#*----------------------------------------------------------------------
* Model Lead Lag
*-----------------------------------------------------------------------
* - Inputs
*		- a input signal
* 
* - Outputs
*		- a output signal
*
* - Assumptions
*
*-----------------------------------------------------------------------
* Author: Tiago Osório
* $Id: lead_lag.mso 1 2006-06-20 17:33:53Z rafael $
*---------------------------------------------------------------------*#

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;
	
end