Visual Servoing Platform  version 3.0.0
servoMomentImage.cpp

Example of moment-based visual servoing with Images

/****************************************************************************
*
* This file is part of the ViSP software.
* Copyright (C) 2005 - 2015 by Inria. All rights reserved.
*
* This software is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* ("GPL") version 2 as published by the Free Software Foundation.
* See the file LICENSE.txt at the root directory of this source
* distribution for additional information about the GNU GPL.
*
* For using ViSP with software that can not be combined with the GNU
* GPL, please contact Inria about acquiring a ViSP Professional
* Edition License.
*
* See http://visp.inria.fr for more information.
*
* This software was developed at:
* Inria Rennes - Bretagne Atlantique
* Campus Universitaire de Beaulieu
* 35042 Rennes Cedex
* France
*
* If you have questions regarding the use of this file, please contact
* Inria at visp@inria.fr
*
* This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
* WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* Description:
* Example of visual servoing with moments using an image as object
* container
*
* Authors:
* Filip Novotny
* Manikandan.B
*****************************************************************************/
#define PRINT_CONDITION_NUMBER
#include <visp3/core/vpDebug.h>
#include <visp3/core/vpConfig.h>
#include <iostream>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/core/vpMomentObject.h>
#include <visp3/core/vpMomentDatabase.h>
#include <visp3/core/vpMomentCommon.h>
#include <visp3/visual_features/vpFeatureMomentCommon.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/gui/vpDisplayGTK.h>
#include <visp3/gui/vpDisplayGDI.h>
#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/core/vpCameraParameters.h>
#include <visp3/core/vpIoTools.h>
#include <visp3/core/vpMath.h>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/vs/vpServo.h>
#include <visp3/core/vpDebug.h>
#include <visp3/visual_features/vpFeatureBuilder.h>
#include <visp3/visual_features/vpFeaturePoint.h>
#include <visp3/robot/vpSimulatorCamera.h>
#include <visp3/robot/vpImageSimulator.h>
#include <visp3/core/vpPlane.h>
#include <visp3/core/vpPoseVector.h>
#include <visp3/gui/vpPlot.h>
#if !defined(_WIN32) && !defined(VISP_HAVE_PTHREAD)
// Robot simulator used in this example is not available
int main()
{
std::cout << "Can't run this example since vpSimulatorAfma6 capability is not available." << std::endl;
std::cout << "You should install pthread third-party library." << std::endl;
}
// No display available
#elif !defined(VISP_HAVE_X11) && !defined(VISP_HAVE_OPENCV) && !defined(VISP_HAVE_GDI) && !defined(VISP_HAVE_D3D9) && !defined(VISP_HAVE_GTK)
int main()
{
std::cout << "Can't run this example since no display capability is available." << std::endl;
std::cout << "You should install one of the following third-party library: X11, OpenCV, GDI, GTK." << std::endl;
}
#else
//setup robot parameters
void paramRobot();
//update moment objects and interface
void refreshScene(vpMomentObject &obj);
//initialize scene in the interface
void initScene();
//initialize the moment features
void initFeatures();
void execute(unsigned int nbIter); //launch the simulation
void setInteractionMatrixType(vpServo::vpServoIteractionMatrixType type);
double error();
void planeToABC(vpPlane& pl, double& A,double& B, double& C);
void paramRobot();
void init_visp_plot(vpPlot& );
int main()
{
try {
//intial pose
vpHomogeneousMatrix cMo(-0.1,-0.1,1.5,-vpMath::rad(20),-vpMath::rad(20),-vpMath::rad(30));
//Desired pose
//init the simulation
init(cMo,cdMo);
execute(1500);
return 0;
}
catch(vpException e) {
std::cout << "Catch an exception: " << e << std::endl;
return 1;
}
}
//init the right display
#if defined VISP_HAVE_X11
vpDisplayX displayInt;
#elif defined VISP_HAVE_OPENCV
vpDisplayOpenCV displayInt;
#elif defined VISP_HAVE_GDI
vpDisplayGDI displayInt;
#elif defined VISP_HAVE_D3D9
vpDisplayD3D displayInt;
#elif defined VISP_HAVE_GTK
vpDisplayGTK displayInt;
#endif
//start and destination positioning matrices
vpSimulatorCamera robot;//robot used in this simulation
vpImage<vpRGBa> Iint(480,640, 0);//internal image used for interface display
vpServo task; //servoing task
vpCameraParameters cam;//robot camera parameters
double _error; //current error
vpImageSimulator imsim;//image simulator used to simulate the perspective-projection camera
//several images used in the simulation
vpImage<unsigned char> cur_img(480,640, 0);
vpImage<unsigned char> src_img(480,640, 0);
vpImage<unsigned char> dst_img(480,640, 0);
vpImage<vpRGBa> start_img(480,640, 0);
vpServo::vpServoIteractionMatrixType interaction_type; //current or desired
//source and destination objects for moment manipulation
//moment sets and their corresponding features
vpMomentCommon *moments;
vpMomentCommon *momentsDes;
vpFeatureMomentCommon *featureMoments;
vpFeatureMomentCommon *featureMomentsDes;
using namespace std;
void initScene(){
for (int i = 0; i < 4; i++) X[i].resize(3);
X[0][0] = -0.2;
X[0][1] = -0.1;
X[0][2] = 0;
X[1][0] = 0.2;
X[1][1] = -0.1;
X[1][2] = 0;
X[2][0] = 0.2;
X[2][1] = 0.1;
X[2][2] = 0;
X[3][0] = -0.2;
X[3][1] = 0.1;
X[3][2] = 0;
//init source and destination images
vpImage<unsigned char> tmp_img(480,640,255);
vpImage<vpRGBa> tmp_start_img(480,640,vpRGBa(255,0,0));
vpImageSimulator imsim_start;
imsim_start.init(tmp_start_img, X);
imsim_start.setCameraPosition(cdMo);
imsim_start.getImage(start_img,cam);
imsim.init(tmp_img, X);
imsim.setCameraPosition(cMo);
imsim.getImage(src_img,cam);
src.fromImage(src_img,128,cam);
imsim.setCameraPosition(cdMo);
imsim.getImage(dst_img,cam);
dst.fromImage(dst_img,128,cam);
}
void refreshScene(vpMomentObject &obj){
cur_img = 0;
imsim.setCameraPosition(cMo);
imsim.getImage(cur_img,cam);
obj.fromImage(cur_img,128,cam);
}
void init(vpHomogeneousMatrix& _cMo, vpHomogeneousMatrix& _cdMo)
{
cMo = _cMo; //init source matrix
cdMo = _cdMo; //init destination matrix
interaction_type = vpServo::CURRENT;//use interaction matrix for current position
displayInt.init(Iint,700,0, "Visual servoing with moments") ;
paramRobot(); //set up robot parameters
initScene(); //initialize graphical scene (for interface)
initFeatures();//initialize moment features
}
void initFeatures(){
//A,B,C parameters of source and destination plane
double A; double B; double C;
double Ad; double Bd; double Cd;
//init main object: using moments up to order 5
//Initializing values from regular plane (with ax+by+cz=d convention)
vpPlane pl;
pl.setABCD(0,0,1.0,0);
pl.changeFrame(cMo);
planeToABC(pl,A,B,C);
pl.setABCD(0,0,1.0,0);
pl.changeFrame(cdMo);
planeToABC(pl,Ad,Bd,Cd);
//extracting initial position (actually we only care about Zdst)
cdMo.extract(vec);
//don't need to be specific, vpMomentCommon automatically loads Xg,Yg,An,Ci,Cj,Alpha moments
//same thing with common features
featureMoments = new vpFeatureMomentCommon(*moments);
featureMomentsDes = new vpFeatureMomentCommon(*momentsDes);
moments->updateAll(src);
momentsDes->updateAll(dst);
featureMoments->updateAll(A,B,C);
featureMomentsDes->updateAll(Ad,Bd,Cd);
//setup the interaction type
task.setInteractionMatrixType(interaction_type) ;
task.addFeature(featureMoments->getFeatureGravityNormalized(),featureMomentsDes->getFeatureGravityNormalized());
task.addFeature(featureMoments->getFeatureAn(),featureMomentsDes->getFeatureAn());
//the moments are different in case of a symmetric object
task.addFeature(featureMoments->getFeatureCInvariant(),featureMomentsDes->getFeatureCInvariant(),(1 << 10) | (1 << 11));
task.addFeature(featureMoments->getFeatureAlpha(),featureMomentsDes->getFeatureAlpha());
task.setLambda(1.);
}
void execute(unsigned int nbIter){
vpPlot ViSP_plot;
init_visp_plot(ViSP_plot); // Initialize plot object
//init main object: using moments up to order 6
//setting object type (disrete, continuous[form polygon])
vpTRACE("Display task information " ) ;
task.print() ;
unsigned int iter=0;
double t=0;
vpHomogeneousMatrix wMo; // Set to identity
vpHomogeneousMatrix wMc; // Camera position in the world frame
wMc = wMo * cMo.inverse();
robot.setPosition(wMc);
float sampling_time = 0.010f; // Sampling period in seconds
robot.setSamplingTime(sampling_time);
// For plotting
vpPoseVector currentpose;
vpColVector err_features;
while(iter++<nbIter ){
//get the cMo
wMc = robot.getPosition();
cMo = wMc.inverse() * wMo;
currentpose.buildFrom(cMo); // For plot
//setup the plane in A,B,C style
vpPlane pl;
double A,B,C;
pl.setABCD(0,0,1.0,0);
pl.changeFrame(cMo);
planeToABC(pl,A,B,C);
//track points, draw points and add refresh our object
refreshScene(obj);
//this is the most important thing to do: update our moments
moments->updateAll(obj);
//and update our features. Do it in that order. Features need to use the information computed by moments
featureMoments->updateAll(A,B,C);
//some graphics again
imsim.setCameraPosition(cMo);
Iint = start_img;
imsim.getImage(Iint,cam);
if (iter == 1)
v = task.computeControlLaw() ;
//pilot robot using position control. The displacement is t*v with t=10ms step
//robot.setPosition(vpRobot::CAMERA_FRAME,0.01*v);
err_features = task.error;
std::cout<<" || s - s* || = "<<task.error.sumSquare()<<std::endl;
vpTime::wait(t, sampling_time * 1000); // Wait 10 ms
ViSP_plot.plot(0,iter, v);
ViSP_plot.plot(1,iter,currentpose); // Plot the velocities
ViSP_plot.plot(2, iter,err_features); //cMo as translations and theta_u
_error = ( task.getError() ).sumSquare();
#if defined(PRINT_CONDITION_NUMBER)
/*
* Condition number of interaction matrix
*/
vpMatrix Linteraction = task.L;
vpMatrix tmpry,U;
vpColVector singularvals;
Linteraction.svd(singularvals, tmpry);
double condno = static_cast<double>(singularvals.getMaxValue()/singularvals.getMinValue());
std::cout<<"Condition Number: "<<condno<<std::endl;
#endif
}
task.kill();
vpTRACE("\n\nClick in the internal view window to end...");
delete moments;
delete momentsDes;
delete featureMoments;
delete featureMomentsDes;
}
void setInteractionMatrixType(vpServo::vpServoIteractionMatrixType type){interaction_type=type;}
double error(){return _error;}
void planeToABC(vpPlane& pl, double& A,double& B, double& C){
if(fabs(pl.getD())<std::numeric_limits<double>::epsilon()){
std::cout << "Invalid position:" << std::endl;
std::cout << cMo << std::endl;
std::cout << "Cannot put plane in the form 1/Z=Ax+By+C." << std::endl;
throw vpException(vpException::divideByZeroError,"invalid position!");
}
A=-pl.getA()/pl.getD();
B=-pl.getB()/pl.getD();
C=-pl.getC()/pl.getD();
}
void paramRobot(){
cam = vpCameraParameters(640,480,320,240);
}
void
init_visp_plot(vpPlot& ViSP_plot) {
/* -------------------------------------
* Initialize ViSP Plotting
* -------------------------------------
*/
const unsigned int NbGraphs = 3; // No. of graphs
const unsigned int NbCurves_in_graph[NbGraphs] = {6,6,6}; // Curves in each graph
ViSP_plot.init(NbGraphs , 800, 800, 10, 10, "Visual Servoing results...");
vpColor Colors[6] = {\
// Colour for s1, s2, s3, in 1st plot
};
for (unsigned int p = 0; p<NbGraphs; p++) {
ViSP_plot.initGraph(p,NbCurves_in_graph[p]);
for (unsigned int c = 0; c<NbCurves_in_graph[p]; c++)
ViSP_plot.setColor(p,c,Colors[c]);
}
ViSP_plot.setTitle(0,"Robot velocities");
ViSP_plot.setLegend(0, 0, "v_x");
ViSP_plot.setLegend(0, 1, "v_y");
ViSP_plot.setLegend(0, 2, "v_z");
ViSP_plot.setLegend(0, 3, "w_x");
ViSP_plot.setLegend(0, 4, "w_y");
ViSP_plot.setLegend(0, 5, "w_z");
ViSP_plot.setTitle(1,"Camera pose cMo");
ViSP_plot.setLegend(1, 0, "tx");
ViSP_plot.setLegend(1, 1, "ty");
ViSP_plot.setLegend(1, 2, "tz");
ViSP_plot.setLegend(1, 3, "tu_x");
ViSP_plot.setLegend(1, 4, "tu_y");
ViSP_plot.setLegend(1, 5, "tu_z");
ViSP_plot.setTitle(2,"Error in visual features: ");
ViSP_plot.setLegend(2, 0, "x_n");
ViSP_plot.setLegend(2, 1, "y_n");
ViSP_plot.setLegend(2, 2, "a_n");
ViSP_plot.setLegend(2, 3, "sx");
ViSP_plot.setLegend(2, 4, "sy");
ViSP_plot.setLegend(2, 5, "alpha");
}
#endif