Visual Servoing Platform  version 3.0.1
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servoAfma62DhalfCamVelocity.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 given thanks to four lines and are the x and y coordinates of the rectangle center, log(Z/Z*) the current depth relative to the desired depth and the thetau rotations.

/****************************************************************************
*
* This file is part of the ViSP software.
* Copyright (C) 2005 - 2017 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/core/vpImagePoint.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/visual_features/vpFeaturePoint.h>
#include <visp3/visual_features/vpFeatureDepth.h>
#include <visp3/visual_features/vpGenericFeature.h>
#include <visp3/core/vpLine.h>
#include <visp3/vs/vpServo.h>
#include <visp3/visual_features/vpFeatureBuilder.h>
#include <visp3/vision/vpPose.h>
#include <visp3/robot/vpRobotAfma6.h>
// Exception
#include <visp3/core/vpException.h>
#include <visp3/vs/vpServoDisplay.h>
#include <visp3/blob/vpDot2.h>
#include <visp3/core/vpPoint.h>
#include <visp3/core/vpHomogeneousMatrix.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 ;
vpRobotAfma6 robot ;
//robot.move("zero.pos") ;
// Update camera parameters
robot.getCameraParameters (cam, I);
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 line " << std::endl ;
std::cout << "-------------------------------------------------------" << std::endl ;
std::cout << std::endl ;
int nbline =4 ;
int nbpoint =4 ;
vpTRACE("sets the desired position of the visual feature ") ;
vpPoint pointd[nbpoint]; //position of the fours corners
vpPoint pointcd; //position of the center of the square
double L=0.05 ;
pointd[0].setWorldCoordinates(L,-L, 0 ) ;
pointd[1].setWorldCoordinates(L,L, 0 ) ;
pointd[2].setWorldCoordinates(-L,L, 0 ) ;
pointd[3].setWorldCoordinates(-L,-L, 0 ) ;
//The coordinates in the object frame of the point used as a feature ie the center of the square
pointcd.setWorldCoordinates(0, 0, 0 ) ;
//The desired homogeneous matrix.
vpHomogeneousMatrix cMod(0,0,0.4,0,0,vpMath::rad(10));
pointd[0].project(cMod);
pointd[1].project(cMod);
pointd[2].project(cMod);
pointd[3].project(cMod);
pointcd.project(cMod);
vpTRACE("Initialization of the tracking") ;
vpMeLine line[nbline] ;
vpPoint point[nbpoint];
int i ;
vpMe me ;
me.setRange(10) ;
me.setPointsToTrack(100) ;
me.setThreshold(50000) ;
me.setSampleStep(10);
//Initialize the tracking. Define the four lines to track
for (i=0 ; i < nbline ; i++)
{
line[i].setMe(&me) ;
line[i].initTracking(I) ;
line[i].track(I) ;
}
// Compute the position of the four corners. The goal is to
// compute the pose
for (i=0 ; i < nbline ; i++)
{
double x=0, y=0;
if (!vpMeLine::intersection (line[i%nbline], line[(i+1)%nbline], ip))
{
exit(-1);
}
point[i].set_x(x) ;
point[i].set_y(y) ;
}
//Compute the pose cMo
vpPose pose ;
pose.clearPoint() ;
point[0].setWorldCoordinates(L,-L, 0 ) ;
point[1].setWorldCoordinates(L,L, 0 ) ;
point[2].setWorldCoordinates(-L,L, 0 ) ;
point[3].setWorldCoordinates(-L,-L, 0 ) ;
for (i=0 ; i < nbline ; i++)
{
pose.addPoint(point[i]) ; // and added to the pose computation point list
}
vpTRACE("sets the current position of the visual feature ") ;
//The first features are the position in the camera frame x and y of the square center
vpPoint pointc; //The current position of the center of the square
double xc = (point[0].get_x()+point[2].get_x())/2;
double yc = (point[0].get_y()+point[2].get_y())/2;
pointc.set_x(xc);
pointc.set_y(yc);
pointc.project(cMo);
//The second feature is the depth of the current square center relative to the depth of the desired square center.
logZ.buildFrom(pointc.get_x(), pointc.get_y(), pointc.get_Z(), log(pointc.get_Z()/pointcd.get_Z()));
//The last three features are the rotations thetau between the current pose and the desired pose.
cdMc = cMod*cMo.inverse() ;
tu.buildFrom(cdMc) ;
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 ;
task.addFeature(p,pd) ;
task.addFeature(logZ) ;
task.addFeature(tu);
vpTRACE("\t set the gain") ;
task.setLambda(0.2) ;
vpTRACE("Display task information " ) ;
task.print() ;
unsigned int iter=0 ;
vpTRACE("\t loop") ;
double lambda_av =0.05;
double alpha = 0.05 ;
double beta =3 ;
for ( ; ; )
{
std::cout << "---------------------------------------------" << iter <<std::endl ;
try {
g.acquire(I) ;
pose.clearPoint() ;
//Track the lines and find the current position of the corners
for (i=0 ; i < nbline ; i++)
{
line[i].track(I) ;
line[i].display(I,vpColor::green);
double x=0, y=0;
if (!vpMeLine::intersection (line[i%nbline], line[(i+1)%nbline], ip))
{
exit(-1);
}
point[i].set_x(x);
point[i].set_y(y);
pose.addPoint(point[i]) ;
}
//Compute the pose
//Update the two first features x and y (position of the square center)
xc = (point[0].get_x()+point[2].get_x())/2;
yc = (point[0].get_y()+point[2].get_y())/2;
pointc.set_x(xc);
pointc.set_y(yc);
pointc.project(cMo);
//Print the current and the desired position of the center of the square
//Print the desired position of the four corners
p.display(cam, I, vpColor::green) ;
pd.display(cam, I, vpColor::red) ;
for (i = 0; i < nbpoint; i++) pointd[i].display(I, cam, vpColor::red);
//Update the second feature
logZ.buildFrom(pointc.get_x(), pointc.get_y(), pointc.get_Z(), log(pointc.get_Z()/pointcd.get_Z()));
//Update the last three features
cdMc = cMod*cMo.inverse() ;
tu.buildFrom(cdMc) ;
//Adaptive 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() ;
std::cout << v.sumSquare() <<std::endl ;
if (iter==0) vpDisplay::getClick(I) ;
if (v.sumSquare() > 0.5)
{
v =0 ;
robot.stopMotion() ;
}
}
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