#*-------------------------------------------------------------------
* 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 of PIDs
*--------------------------------------------------------------------
*  - Inputs
*	- a scaled processs variable
*	- a scaled bias
*	- a scaled setpoint
*
*  - Outputs
*   - a scaled output
*
*
*--------------------------------------------------------------------
* Author: Tiago Osório
* $Id: PIDs.mso 74 2006-12-08 18:43:02Z paula $
*-------------------------------------------------------------------*#
using "types";

Model MParameters

	VARIABLES
	
	alpha      as positive (Brief="Derivative term filter constant", Default=1);
	beta       as positive (Brief="Proportional term setPoint change filter");
	bias       as control_signal (Brief="Previous scaled bias", Default=0.5);
	derivTime  as time_sec (Brief="Derivative time constant");
	intTime    as time_sec (Brief="Integral time constant");
	gain       as positive (Brief="Controller gain", Default=0.5);
	gamma      as positive (Brief="Derivative term SP change filter");
	tau        as time_sec (Brief="Input filter time constant");
	tauSet     as time_sec (Brief="Input filter time constant");

end

Model MOptions	

	VARIABLES	
	
	action	   as Real     (Brief="Controller action: (-1) Direct,(1) Reverse", Default=-1);
    autoMan    as Real     (Brief="Controller option: (0) Automatic, (1) Manual", Default=0);    
	clip       as Real     (Brief="Controller option: (1) output clipped, (0) output unclipped", Default=1);

end

Model MPorts

	VARIABLES
	
	input      as control_signal (Brief="Previous scaled input signal", Default=0.5);
	output     as control_signal (Brief="Scaled output signal", Default=0.5);
	setPoint   as control_signal (Brief="Scaled setPoint",Default=0.5);

end

Model MInternal_Variables
	
	VARIABLES

	derivTerm  as control_signal (Brief="Derivative term", Default=0);
	dFilt      as control_signal (Brief="Derivative term filtered", Default=0.5);
	error      as control_signal (Brief="Error definition for proportional term");
	errorD     as control_signal (Brief="Error definition for derivative term");
	errorI     as control_signal (Brief="Error definition for integral term");
	inputFilt  as control_signal (Brief="Filtered input");
	intTerm    as control_signal (Brief="Integral term", Default=0);
	outp       as control_signal (Brief="Sum of proportional, integral and derivative terms");
	outps      as control_signal (Brief="Variable outp scaled between -1 and 1");
	propTerm   as control_signal (Brief="Proportional term", Default=0);
	setPointFilt  as control_signal (Brief="Filtered setPoint", Default=0);

end

Model PID_basic

	VARIABLES
	Parameters         as MParameters;
	Options            as MOptions;
	Internal           as MInternal_Variables;
	Ports              as MPorts;
	
	EQUATIONS

	if (Parameters.tau equal 0) then
		"Input first order filter"
		(Parameters.tau + 1e-3*"s")*diff(Internal.inputFilt)= Ports.input - Internal.inputFilt;
	else
		"Input first order filter"
		Parameters.tau*diff(Internal.inputFilt)= Ports.input - Internal.inputFilt;	
	end

	if (Parameters.tauSet equal 0) then
		"setPoint first order filter"
		(Parameters.tauSet + 1e-3*"s")*diff(Internal.setPointFilt)= Ports.setPoint - Internal.setPointFilt;
	else
		"setPoint first order filter"
		Parameters.tauSet*diff(Internal.setPointFilt)= Ports.setPoint - Internal.setPointFilt;
	end
	
	if Options.autoMan equal 1 then 
		"Error definition for proportional term"
		Internal.error = Internal.inputFilt*(Parameters.beta-1.0);
		"Error definition for derivative term"
		Internal.errorD= Internal.inputFilt*(Parameters.gamma-1.0);
		"Error definition for integral term"		
		Internal.errorI= 0;
	else
		"Error definition for proportional term"			
		Internal.error = Parameters.beta*Internal.setPointFilt - Internal.inputFilt;
		"Error definition for derivative term"
		Internal.errorD = Parameters.gamma*Internal.setPointFilt - Internal.inputFilt;
		"Error definition for integral term"
		Internal.errorI = Internal.setPointFilt-Internal.inputFilt;
	end
	
	"Calculate proportional term"
	Internal.propTerm=Internal.error;
	
	if (Parameters.derivTime equal 0) then
		"Derivative term filter"	
		Parameters.alpha*(Parameters.derivTime + 1e-3*"s")*diff(Internal.dFilt) = Internal.errorD - Internal.dFilt;
	else
		"Derivative term filter"	
		Parameters.alpha*(Parameters.derivTime)*diff(Internal.dFilt) = Internal.errorD - Internal.dFilt;
	end

	"Calculate derivative term"
	Internal.derivTerm = Parameters.derivTime*diff(Internal.dFilt);
	
	"Scale outp"
	Internal.outps=2*Internal.outp-1;
	
	if Options.clip equal 1 then
		if abs(Internal.outps)>1 then
			"Calculate clipped output when itīs saturated"
			Ports.output=(sign(Internal.outps)*1+1)/2;
		else
			"Calculate clipped output when itīs not saturated"
			Ports.output=Internal.outp;
		end
	else
		"Calculate unclipped output"
		Ports.output=Internal.outp;
	end

	INITIAL
	Internal.intTerm = 0;
	diff(Internal.dFilt) = 0*"1/s";
	diff(Internal.inputFilt) = 0*"1/s";
	diff(Internal.setPointFilt) = 0*"1/s";
end


Model PID_Ideal_AW as PID_basic
	
	VARIABLES
	AWFactor     as Real     (Brief="Integral term multiplier used in anti-reset windup");

	EQUATIONS
	
	"Calculate integral term with anti-windup"
	Parameters.intTime*diff(Internal.intTerm) = AWFactor*Internal.errorI;
	
	"Sum of proportional, integral and derivative terms"
	Internal.outp = Parameters.bias + Options.action*Parameters.gain*(Internal.propTerm + Internal.intTerm + Internal.derivTerm);

	if abs(Internal.outps)>1 and (Options.action*sign(Internal.outps)*Internal.errorI)>0 then
		"Calculate AWFactor"
		AWFactor=-tanh(sign(Internal.outps)*Internal.outps*100-102);
	else
		"Calculate AWFactor"
		AWFactor=1;
	end
end

Model PID_Parallel_AW as PID_basic
	
	VARIABLES
	AWFactor     as Real     (Brief="Integral term multiplier used in anti-reset windup");

	EQUATIONS
	
	"Calculate integral term with anti-windup"
	Parameters.intTime*diff(Internal.intTerm) = AWFactor*Internal.errorI;
	
	"Sum of proportional, integral and derivative terms"
	Internal.outp = Parameters.bias + Options.action*(Parameters.gain*Internal.propTerm + Internal.intTerm + Internal.derivTerm);

	if abs(Internal.outps)>1 and (Options.action*sign(Internal.outps)*Internal.errorI)>0 then
		"Calculate AWFactor"
		AWFactor=-tanh(sign(Internal.outps)*Internal.outps*100-102);
	else
		"Calculate AWFactor"
		AWFactor=1;
	end
end

Model PID_Series_AW as PID_basic
	
	VARIABLES
	AWFactor     as Real     (Brief="Integral term multiplier used in anti-reset windup");
	
	EQUATIONS
	
	"Calculate integral term with anti-windup"	
	Parameters.intTime*diff(Internal.intTerm) = AWFactor*Internal.errorI;
	
	"Sum of proportional, integral and derivative terms"
	Internal.outp = Parameters.bias + Options.action*(Parameters.gain*(Internal.propTerm + Internal.intTerm)*(1 + Internal.derivTerm));

	if abs(Internal.outps)>1 and (Options.action*sign(Internal.outps)*Internal.errorI)>0 then
		"Calculate AWFactor"		
		AWFactor=-tanh(sign(Internal.outps)*Internal.outps*100-102);
	else
		"Calculate AWFactor"
		AWFactor=1;
	end
end

Model PID_Ideal as PID_basic
	
	EQUATIONS
	
	"Calculate integral term"	
	Parameters.intTime*diff(Internal.intTerm) = Internal.errorI;
	
	"Sum of proportional, integral and derivative terms"	
	Internal.outp = Parameters.bias + Options.action*Parameters.gain*(Internal.propTerm + Internal.intTerm + Internal.derivTerm);

end

Model PID_Parallel as PID_basic
	
	EQUATIONS
	
	"Calculate integral term"	
	Parameters.intTime*diff(Internal.intTerm) = Internal.errorI;
	
	"Sum of proportional, integral and derivative terms"	
	Internal.outp = Parameters.bias + Options.action*(Parameters.gain*Internal.propTerm + Internal.intTerm + Internal.derivTerm);

end

Model PID_Series as PID_basic
	
	EQUATIONS
	
	"Calculate integral term"	
	Parameters.intTime*diff(Internal.intTerm) = Internal.errorI;
	
	"Sum of proportional, integral and derivative terms"
	Internal.outp = Parameters.bias + Options.action*(Parameters.gain*(Internal.propTerm + Internal.intTerm)*(1 + Internal.derivTerm));

end

Model PID_Ideal_AWBT as PID_basic
	
	EQUATIONS
	
	"Calculate integral term with anti-windup and bumpless transfer"	
	Options.action*Parameters.gain*(Parameters.intTime*diff(Internal.intTerm)-Internal.errorI) = Ports.output-Internal.outp;	
	
	"Sum of proportional, integral and derivative terms"	
	Internal.outp = Parameters.bias + Options.action*Parameters.gain*(Internal.propTerm + Internal.intTerm + Internal.derivTerm);

end

Model PID_Parallel_AWBT as PID_basic
	
	EQUATIONS
	
	"Calculate integral term with anti-windup and bumpless transfer"	
	Options.action*Parameters.gain*(Parameters.intTime*diff(Internal.intTerm)-Internal.errorI) = Ports.output-Internal.outp;	
	
	"Sum of proportional, integral and derivative terms"	
	Internal.outp = Parameters.bias + Options.action*(Parameters.gain*Internal.propTerm + Internal.intTerm + Internal.derivTerm);

end

Model PID_Series_AWBT as PID_basic
	
	EQUATIONS
	
	"Calculate integral term with anti-windup and bumpless transfer"
	Options.action*Parameters.gain*(Parameters.intTime*diff(Internal.intTerm)-Internal.errorI) = Ports.output-Internal.outp;	
	
	"Sum of proportional, integral and derivative terms"
	Internal.outp = Parameters.bias + Options.action*(Parameters.gain*(Internal.propTerm + Internal.intTerm)*(1 + Internal.derivTerm));

end