Visual Servoing Platform  version 3.0.0
servoAfma6Cylinder2DCamVelocitySecondaryTask.cpp

Example of eye-in-hand control law. We control here a real robot, the Afma6 robot (cartesian robot, with 6 degrees of freedom). The velocity is computed in the camera frame. Visual features are the two lines corresponding to the edges of a cylinder.

This example illustrates in one hand a classical visual servoing with a cylinder. And in the other hand it illustrates the behaviour of the robot when adding a secondary task.

/****************************************************************************
*
* 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:
* tests the control law
* eye-in-hand control
* velocity computed in the camera frame
*
* Authors:
* Nicolas Melchior
*
*****************************************************************************/
#include <visp3/core/vpConfig.h>
#include <visp3/core/vpDebug.h> // Debug trace
#include <stdlib.h>
#include <cmath> // std::fabs
#include <limits> // numeric_limits
#if (defined (VISP_HAVE_AFMA6) && defined (VISP_HAVE_DC1394))
#include <visp3/sensor/vp1394TwoGrabber.h>
#include <visp3/core/vpImage.h>
#include <visp3/io/vpImageIo.h>
#include <visp3/core/vpDisplay.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/gui/vpDisplayGTK.h>
#include <visp3/core/vpMath.h>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/visual_features/vpFeatureLine.h>
#include <visp3/me/vpMeLine.h>
#include <visp3/core/vpCylinder.h>
#include <visp3/vs/vpServo.h>
#include <visp3/visual_features/vpFeatureBuilder.h>
#include <visp3/robot/vpRobotAfma6.h>
// Exception
#include <visp3/core/vpException.h>
#include <visp3/vs/vpServoDisplay.h>
int
main()
{
try
{
g.open(I) ;
g.acquire(I) ;
#ifdef VISP_HAVE_X11
vpDisplayX display(I,100,100,"Current image") ;
#elif defined(VISP_HAVE_OPENCV)
vpDisplayOpenCV display(I,100,100,"Current image") ;
#elif defined(VISP_HAVE_GTK)
vpDisplayGTK display(I,100,100,"Current image") ;
#endif
vpServo task ;
std::cout << std::endl ;
std::cout << "-------------------------------------------------------" << std::endl ;
std::cout << " Test program for vpServo " <<std::endl ;
std::cout << " Eye-in-hand task control, velocity computed in the camera frame" << std::endl ;
std::cout << " Simulation " << std::endl ;
std::cout << " task : servo a point " << std::endl ;
std::cout << "-------------------------------------------------------" << std::endl ;
std::cout << std::endl ;
int i ;
int nbline =2 ;
vpMeLine line[nbline] ;
vpMe me ;
me.setRange(20) ;
me.setPointsToTrack(100) ;
me.setThreshold(2000) ;
me.setSampleStep(10);
//Initialize the tracking of the two edges of the cylinder
for (i=0 ; i < nbline ; i++)
{
line[i].setMe(&me) ;
line[i].initTracking(I) ;
line[i].track(I) ;
}
vpRobotAfma6 robot ;
//robot.move("zero.pos") ;
// Update camera parameters
robot.getCameraParameters (cam, I);
vpTRACE("sets the current position of the visual feature ") ;
vpFeatureLine p[nbline] ;
for (i=0 ; i < nbline ; i++)
vpFeatureBuilder::create(p[i],cam, line[i]) ;
vpTRACE("sets the desired position of the visual feature ") ;
vpCylinder cyld(0,1,0,0,0,0,0.04);
vpHomogeneousMatrix cMo(0,0,0.5,0,0,vpMath::rad(0));
cyld.project(cMo);
vpFeatureLine pd[nbline] ;
//Those lines are needed to keep the conventions define in vpMeLine (Those in vpLine are less restrictive)
//Another way to have the coordinates of the desired features is to learn them before executing the program.
pd[0].setRhoTheta(-fabs(pd[0].getRho()),0);
pd[1].setRhoTheta(-fabs(pd[1].getRho()),M_PI);
vpTRACE("define the task") ;
vpTRACE("\t we want an eye-in-hand control law") ;
vpTRACE("\t robot is controlled in the camera frame") ;
vpTRACE("\t we want to see a point on a point..") ;
std::cout << std::endl ;
for (i=0 ; i < nbline ; i++)
task.addFeature(p[i],pd[i]) ;
vpTRACE("\t set the gain") ;
task.setLambda(0.3) ;
vpTRACE("Display task information " ) ;
task.print() ;
unsigned int iter=0 ;
vpTRACE("\t loop") ;
double lambda_av =0.05;
double alpha = 0.02;
double beta =3;
double erreur = 1;
//First loop to reach the convergence position
while(erreur > 0.00001)
{
std::cout << "---------------------------------------------" << iter <<std::endl ;
try {
g.acquire(I) ;
//Track the two edges and update the features
for (i=0 ; i < nbline ; i++)
{
line[i].track(I) ;
line[i].display(I, vpColor::red) ;
vpFeatureBuilder::create(p[i],cam,line[i]);
p[i].display(cam, I, vpColor::red) ;
pd[i].display(cam, I, vpColor::green) ;
}
//Adaptative gain
double gain ;
{
if (std::fabs(alpha) <= std::numeric_limits<double>::epsilon())
gain = lambda_av ;
else
{
gain = alpha * exp (-beta * ( task.getError() ).sumSquare() ) + lambda_av ;
}
}
task.setLambda(gain) ;
v = task.computeControlLaw() ;
if (iter==0) vpDisplay::getClick(I) ;
}
catch(...)
{
v =0 ;
robot.stopMotion() ;
exit(1) ;
}
erreur = ( task.getError() ).sumSquare();
vpTRACE("\t\t || s - s* || = %f ", ( task.getError() ).sumSquare()) ;
iter++;
}
/**********************************************************************************************/
//Second loop is to compute the control while taking into account the secondary task.
vpColVector e1(6) ; e1 = 0 ;
vpColVector e2(6) ; e2 = 0 ;
vpColVector proj_e1 ;
vpColVector proj_e2 ;
iter = 0;
double rapport = 0;
double vitesse = 0.02;
unsigned int tempo = 1200;
for ( ; ; )
{
std::cout << "---------------------------------------------" << iter <<std::endl ;
try {
g.acquire(I) ;
//Track the two edges and update the features
for (i=0 ; i < nbline ; i++)
{
line[i].track(I) ;
line[i].display(I, vpColor::red) ;
vpFeatureBuilder::create(p[i],cam,line[i]);
p[i].display(cam, I, vpColor::red) ;
pd[i].display(cam, I, vpColor::green) ;
}
v = task.computeControlLaw() ;
//Compute the new control law corresponding to the secondary task
if ( iter%tempo < 400 /*&& iter%tempo >= 0*/)
{
e2 = 0;
e1[0] = fabs(vitesse) ;
proj_e1 = task.secondaryTask(e1);
rapport = vitesse/proj_e1[0];
proj_e1 *= rapport ;
v += proj_e1 ;
if ( iter == 199 ) iter+=200; //This line is needed to make on ly an half turn during the first cycle
}
if ( iter%tempo < 600 && iter%tempo >= 400)
{
e1 = 0;
e2[1] = fabs(vitesse) ;
proj_e2 = task.secondaryTask(e2);
rapport = vitesse/proj_e2[1];
proj_e2 *= rapport ;
v += proj_e2 ;
}
if ( iter%tempo < 1000 && iter%tempo >= 600)
{
e2 = 0;
e1[0] = -fabs(vitesse) ;
proj_e1 = task.secondaryTask(e1);
rapport = -vitesse/proj_e1[0];
proj_e1 *= rapport ;
v += proj_e1 ;
}
if ( iter%tempo < 1200 && iter%tempo >= 1000)
{
e1 = 0;
e2[1] = -fabs(vitesse) ;
proj_e2 = task.secondaryTask(e2);
rapport = -vitesse/proj_e2[1];
proj_e2 *= rapport ;
v += proj_e2 ;
}
}
catch(...)
{
v =0 ;
robot.stopMotion() ;
exit(1) ;
}
vpTRACE("\t\t || s - s* || = %f ", ( task.getError() ).sumSquare()) ;
iter++;
}
vpTRACE("Display task information " ) ;
task.print() ;
task.kill();
}
catch (...)
{
vpERROR_TRACE(" Test failed") ;
return 0;
}
}
#else
int
main()
{
vpERROR_TRACE("You do not have an afma6 robot or a firewire framegrabber connected to your computer...");
}
#endif