Visual Servoing Platform  version 3.4.0
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.

/****************************************************************************
*
* ViSP, open source Visual Servoing Platform software.
* Copyright (C) 2005 - 2019 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 as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
* 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 <cmath> // std::fabs
#include <limits> // numeric_limits
#include <stdlib.h>
#include <visp3/core/vpConfig.h>
#include <visp3/core/vpDebug.h> // Debug trace
#if (defined(VISP_HAVE_AFMA6) && defined(VISP_HAVE_DC1394))
#include <visp3/core/vpDisplay.h>
#include <visp3/core/vpImage.h>
#include <visp3/gui/vpDisplayGTK.h>
#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/io/vpImageIo.h>
#include <visp3/sensor/vp1394TwoGrabber.h>
#include <visp3/core/vpCylinder.h>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/core/vpMath.h>
#include <visp3/me/vpMeLine.h>
#include <visp3/visual_features/vpFeatureBuilder.h>
#include <visp3/visual_features/vpFeatureLine.h>
#include <visp3/vs/vpServo.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.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)
} 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();
return EXIT_SUCCESS;
}
catch (const vpException &e) {
std::cout << "Test failed with exception: " << e << std::endl;
return EXIT_FAILURE;
}
}
#else
int main()
{
std::cout << "You do not have an afma6 robot connected to your computer..." << std::endl;
return EXIT_SUCCESS;
}
#endif