/* Class PropDeriv
*
* This class contains the constructor to create an instance of
* a Proportional plus Derivative(PD) controller and the methods
* needed to use this controller in control loops in the time
* domain, Laplace transform s domain or the z-transform z domain.
*
* This class is a subclass of the superclass BlackBox.
*
* Author: Michael Thomas Flanagan.
*
* Created: August 2002
* Updated: 17 April 2003, 2 May 2005, 2 July 2006, 6 April 2008
*
*
* DOCUMENTATION:
* See Michael T Flanagan's JAVA library on-line web page:
* http://www.ee.ucl.ac.uk/~mflanaga/java/PropDeriv.html
* http://www.ee.ucl.ac.uk/~mflanaga/java/
*
* Copyright (c) 2006 - 2008 Michael Thomas Flanagan
*
* PERMISSION TO COPY:
* Permission to use, copy and modify this software and its documentation for
* NON-COMMERCIAL purposes is granted, without fee, provided that an acknowledgement
* to the author, Michael Thomas Flanagan at www.ee.ac.uk/~mflanaga, appears in all copies.
*
* Dr Michael Thomas Flanagan makes no representations about the suitability
* or fitness of the software for any or for a particular purpose.
* Michael Thomas Flanagan shall not be liable for any damages suffered
* as a result of using, modifying or distributing this software or its derivatives.
*
***************************************************************************************/
package flanagan.control;
import flanagan.complex.Complex;
import flanagan.complex.ComplexPoly;
import flanagan.plot.Plot;
import flanagan.plot.PlotGraph;
public class PropDeriv extends BlackBox{
private double kp = 1.0D; // proportional gain
private double td = 0.0D; // derivative time constant
private double kd = 0.0D; // derivative gain
// Constructor - unit proportional gain, zero derivative gain
public PropDeriv(){
super("PD");
super.sNumerDeg = 1;
super.sDenomDeg = 0;
super.setSnumer(new ComplexPoly(1.0D, 0.0D));
super.setSdenom(new ComplexPoly(1.0D));
super.setZtransformMethod(1);
super.addDeadTimeExtras();
}
// Set the proportional gain
public void setKp(double kp){
this.kp = kp;
super.sNumer.resetCoeff(0, new Complex(this.kp, 0.0D));
super.sZeros[0].reset(-this.kp/this.kd, 0.0D);
super.addDeadTimeExtras();
}
// Set the derivative gain
public void setKd(double kd){
this.kd=kd;
this.td=kd/this.kp;
super.sNumer.resetCoeff(1, new Complex(this.kd, 0.0D));
super.sZeros[0].reset(-this.kp/this.kd, 0.0D);
super.addDeadTimeExtras();
}
// Set the derivative time constant
public void setTd(double td){
this.td=td;
this.kd=this.td*this.kp;
super.sNumer.resetCoeff(1, new Complex(this.kd, 0.0D));
super.sZeros[0].reset(-this.kp/this.kd, 0.0D);
super.addDeadTimeExtras();
}
// Get the proprtional gain
public double getKp(){
return this.kp;
}
// Get the derivative gain
public double getKd(){
return this.kd;
}
// Get the derivative time constant
public double getTd(){
return this.td;
}
// Perform z transform using an already set delta T
public void zTransform(){
if(super.deltaT==0.0D)System.out.println("z-transform attempted in PropDeriv with a zero sampling period");
super.deadTimeWarning("zTransform");
if(ztransMethod==0){
this.mapstozAdHoc();
}
else{
super.zNumerDeg = 1;
super.zDenomDeg = 1;
super.zNumer = new ComplexPoly(-this.kd, this.kp*super.deltaT + this.kd);
super.zDenom = new ComplexPoly(0.0D, super.deltaT);
super.zZeros = Complex.oneDarray(1);
super.zZeros[0].reset(this.kd/(this.kp*super.deltaT + this.kd),0.0D);
super.zPoles = Complex.oneDarray(1);
super.zPoles[0].reset(0.0D, 0.0D);
}
}
// Perform z transform setting delta T
public void zTransform(double deltaT){
super.deltaT=deltaT;
super.deadTimeWarning("zTransform");
zTransform();
}
// Plots the time course for a step input
public void stepInput(double stepMag, double finalTime){
// Calculate time course outputs
int n = 50; // number of points on plot
double incrT = finalTime/(double)(n-1); // plotting increment
double cdata[][] = new double [2][n]; // plotting array
cdata[0][0]=0.0D;
for(int i=1; i<n; i++){
cdata[0][i]=cdata[0][i-1]+incrT;
}
double kpterm = this.kp*stepMag;
for(int i=0; i<n; i++){
cdata[1][i] = kpterm;
}
if(super.deadTime!=0.0D)for(int i=0; i<n; i++)cdata[0][i] += super.deadTime;
// Plot
PlotGraph pg = new PlotGraph(cdata);
pg.setGraphTitle("Step Input Transient: Step magnitude = "+stepMag);
pg.setGraphTitle2(this.getName());
pg.setXaxisLegend("Time");
pg.setXaxisUnitsName("s");
pg.setYaxisLegend("Output");
pg.setPoint(0);
pg.plot();
}
// Plots the time course for a unit step input
public void stepInput(double finalTime){
this.stepInput(1.0D, finalTime);
}
// Plots the time course for an nth order ramp input (at^n)
public void rampInput(double rampGradient, int rampOrder, double finalTime){
if(rampOrder==0){
// Check if really a step input (rampOrder, n = 0)
this.stepInput(rampGradient, finalTime);
}
else{
// Calculate time course outputs
int n = 50; // number of points on plot
double incrT = finalTime/(double)(n-1); // plotting increment
double cdata[][] = new double [2][n]; // plotting array
double sum = 0.0D; // integration sum
cdata[0][0]=0.0D;
cdata[1][0]=0.0D;
for(int i=1; i<n; i++){
cdata[0][i]=cdata[0][i-1]+incrT;
cdata[1][i] = rampGradient*Math.pow(cdata[0][i],rampOrder-1)*(this.kp*cdata[0][i] + this.kd);
}
if(super.deadTime!=0.0D)for(int i=0; i<n; i++)cdata[0][i] += super.deadTime;
// Plot
PlotGraph pg = new PlotGraph(cdata);
pg.setGraphTitle("Ramp (a.t^n) Input Transient: ramp gradient (a) = "+rampGradient + " ramp order (n) = " + rampOrder);
pg.setGraphTitle2(this.getName());
pg.setXaxisLegend("Time");
pg.setXaxisUnitsName("s");
pg.setYaxisLegend("Output");
pg.setPoint(0);
pg.plot();
}
}
// Plots the time course for an nth order ramp input (t^n)
public void rampInput(int rampOrder, double finalTime){
double rampGradient = 1.0D;
this.rampInput(rampGradient, rampOrder, finalTime);
}
// Plots the time course for a first order ramp input (at)
public void rampInput(double rampGradient, double finalTime){
int rampOrder = 1;
this.rampInput(rampGradient, rampOrder, finalTime);
}
// Plots the time course for a unit ramp input (t)
public void rampInput(double finalTime){
double rampGradient = 1.0D;
int rampOrder = 1;
this.rampInput(rampGradient, rampOrder, finalTime);
}
// Get the s-domain output for a given s-value and a given input.
public Complex getOutputS(Complex sValue, Complex iinput){
super.sValue=sValue;
super.inputS=iinput;
Complex term = this.sValue.times(this.kd);
term = term.plus(this.kp);
super.outputS=term.times(super.inputS);
if(super.deadTime!=0.0D)super.outputS = super.outputS.times(Complex.exp(super.sValue.times(-super.deadTime)));
return super.outputS;
}
// Get the s-domain output for the stored input and s-value.
public Complex getOutputS(){
Complex term = this.sValue.times(this.kd);
term = term.plus(this.kp);
super.outputS=term.times(super.inputS);
if(super.deadTime!=0.0D)super.outputS = super.outputS.times(Complex.exp(super.sValue.times(-super.deadTime)));
return super.outputS;
}
// Calculate the current time domain output for a given input and given time
// resets deltaT
public void calcOutputT(double ttime, double inp){
if(ttime<=time[this.sampLen-1])throw new IllegalArgumentException("Current time equals or is less than previous time");
super.deltaT = ttime - super.time[this.sampLen-1];
super.sampFreq = 1.0D/super.deltaT;
super.deadTimeWarning("calcOutputT(time, input)");
for(int i=0; i<super.sampLen-2; i++){
super.time[i]=super.time[i+1];
super.inputT[i]=super.inputT[i+1];
super.outputT[i]=super.outputT[i+1];
}
super.time[super.sampLen-1]=ttime;
super.inputT[super.sampLen-1]=inp;
super.outputT[super.sampLen-1]=Double.NaN;
this.calcOutputT();
}
// Get the output for the stored sampled input, time and deltaT.
public void calcOutputT(){
// proportional term
super.outputT[super.sampLen-1] = this.kp*super.inputT[sampLen-1];
// + derivative term
super.outputT[super.sampLen-1] += this.kd*(super.inputT[super.sampLen-1]-super.inputT[super.sampLen-2])/super.deltaT;
}
// Get the s-domain poles
public Complex[] getSpoles(){
System.out.println("PD controller has no s-domain poles");
return null;
}
// Deep copy
public PropDeriv copy(){
if(this==null){
return null;
}
else{
PropDeriv bb = new PropDeriv();
bb.kp = this.kp;
bb.td = this.td;
bb.kd = this.kd;
bb.sampLen = this.sampLen;
bb.inputT = this.inputT.clone();
bb.outputT = this.outputT.clone();
bb.time = this.time.clone();
bb.forgetFactor = this.forgetFactor;
bb.deltaT = this.deltaT;
bb.sampFreq = this.sampFreq;
bb.inputS = this.inputS.copy();
bb.outputS = this.outputS.copy();
bb.sValue = this.sValue.copy();
bb.zValue = this.zValue.copy();
bb.sNumer = this.sNumer.copy();
bb.sDenom = this.sDenom.copy();
bb.zNumer = this.zNumer.copy();
bb.zDenom = this.zDenom.copy();
bb.sPoles = Complex.copy(this.sPoles);
bb.sZeros = Complex.copy(this.sZeros);
bb.zPoles = Complex.copy(this.zPoles);
bb.zZeros = Complex.copy(this.zZeros);
bb.sNumerDeg = this.sNumerDeg;
bb.sDenomDeg = this.sDenomDeg;
bb.zNumerDeg = this.zNumerDeg;
bb.zDenomDeg = this.zDenomDeg;
bb.deadTime = this.deadTime;
bb.orderPade = this.orderPade;
bb.sNumerPade = this.sNumerPade.copy();
bb.sDenomPade = this.sDenomPade.copy();
bb.sPolesPade = Complex.copy(this.sPolesPade);
bb.sZerosPade = Complex.copy(this.sZerosPade);
bb.sNumerDegPade = this.sNumerDegPade;
bb.sDenomDegPade = this.sDenomDegPade;
bb.maptozero = this.maptozero;
bb.padeAdded = this.padeAdded;
bb.integrationSum = this.integrationSum;
bb.integMethod = this.integMethod;
bb.ztransMethod = this.ztransMethod;
bb.name = this.name;
bb.fixedName = this.fixedName;
bb.nPlotPoints = this.nPlotPoints;
return bb;
}
}
// Clone - overrides Java.Object method clone
public Object clone(){
Object ret = null;
if(this!=null){
PropDeriv bb = new PropDeriv();
bb.kp = this.kp;
bb.td = this.td;
bb.kd = this.kd;
bb.sampLen = this.sampLen;
bb.inputT = this.inputT.clone();
bb.outputT = this.outputT.clone();
bb.time = this.time.clone();
bb.forgetFactor = this.forgetFactor;
bb.deltaT = this.deltaT;
bb.sampFreq = this.sampFreq;
bb.inputS = this.inputS.copy();
bb.outputS = this.outputS.copy();
bb.sValue = this.sValue.copy();
bb.zValue = this.zValue.copy();
bb.sNumer = this.sNumer.copy();
bb.sDenom = this.sDenom.copy();
bb.zNumer = this.zNumer.copy();
bb.zDenom = this.zDenom.copy();
bb.sPoles = Complex.copy(this.sPoles);
bb.sZeros = Complex.copy(this.sZeros);
bb.zPoles = Complex.copy(this.zPoles);
bb.zZeros = Complex.copy(this.zZeros);
bb.sNumerDeg = this.sNumerDeg;
bb.sDenomDeg = this.sDenomDeg;
bb.zNumerDeg = this.zNumerDeg;
bb.zDenomDeg = this.zDenomDeg;
bb.deadTime = this.deadTime;
bb.orderPade = this.orderPade;
bb.sNumerPade = this.sNumerPade.copy();
bb.sDenomPade = this.sDenomPade.copy();
bb.sPolesPade = Complex.copy(this.sPolesPade);
bb.sZerosPade = Complex.copy(this.sZerosPade);
bb.sNumerDegPade = this.sNumerDegPade;
bb.sDenomDegPade = this.sDenomDegPade;
bb.maptozero = this.maptozero;
bb.padeAdded = this.padeAdded;
bb.integrationSum = this.integrationSum;
bb.integMethod = this.integMethod;
bb.ztransMethod = this.ztransMethod;
bb.name = this.name;
bb.fixedName = this.fixedName;
bb.nPlotPoints = this.nPlotPoints;
ret = (Object) bb;
}
return ret;
}
}