servoAfma6SquareLines2DCamVelocity.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 four lines of a square.

/****************************************************************************
 *
 * 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.
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 * 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:
 * Eric Marchand
 *
 *****************************************************************************/
#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/vpHomogeneousMatrix.h>
#include <visp3/core/vpLine.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 {
    vpImage<unsigned char> I;

    vp1394TwoGrabber g;
    g.setVideoMode(vp1394TwoGrabber::vpVIDEO_MODE_640x480_MONO8);
    g.setFramerate(vp1394TwoGrabber::vpFRAMERATE_60);
    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

    vpDisplay::display(I);
    vpDisplay::flush(I);

    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 line " << std::endl;
    std::cout << "-------------------------------------------------------" << std::endl;
    std::cout << std::endl;

    int i;
    int nbline = 4;

    vpMeLine line[nbline];

    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].setDisplay(vpMeSite::RANGE_RESULT);
      line[i].setMe(&me);

      line[i].initTracking(I);
      line[i].track(I);
    }

    vpRobotAfma6 robot;
    // robot.move("zero.pos") ;

    vpCameraParameters cam;
    // 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 ");
    vpLine lined[nbline];
    lined[0].setWorldCoordinates(1, 0, 0, 0.05, 0, 0, 1, 0);
    lined[1].setWorldCoordinates(0, 1, 0, 0.05, 0, 0, 1, 0);
    lined[2].setWorldCoordinates(1, 0, 0, -0.05, 0, 0, 1, 0);
    lined[3].setWorldCoordinates(0, 1, 0, -0.05, 0, 0, 1, 0);

    vpHomogeneousMatrix cMo(0, 0, 0.5, 0, 0, vpMath::rad(0));

    lined[0].project(cMo);
    lined[1].project(cMo);
    lined[2].project(cMo);
    lined[3].project(cMo);

    // 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.
    lined[0].setRho(-fabs(lined[0].getRho()));
    lined[0].setTheta(0);
    lined[1].setRho(-fabs(lined[1].getRho()));
    lined[1].setTheta(M_PI / 2);
    lined[2].setRho(-fabs(lined[2].getRho()));
    lined[2].setTheta(M_PI);
    lined[3].setRho(-fabs(lined[3].getRho()));
    lined[3].setTheta(-M_PI / 2);

    vpFeatureLine pd[nbline];

    vpFeatureBuilder::create(pd[0], lined[0]);
    vpFeatureBuilder::create(pd[1], lined[1]);
    vpFeatureBuilder::create(pd[2], lined[2]);
    vpFeatureBuilder::create(pd[3], lined[3]);

    vpTRACE("define the task");
    vpTRACE("\t we want an eye-in-hand control law");
    vpTRACE("\t robot is controlled in the camera frame");
    task.setServo(vpServo::EYEINHAND_CAMERA);
    task.setInteractionMatrixType(vpServo::DESIRED, vpServo::PSEUDO_INVERSE);

    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(0.2);

    vpTRACE("Display task information ");
    task.print();

    robot.setRobotState(vpRobot::STATE_VELOCITY_CONTROL);

    unsigned int iter = 0;
    vpTRACE("\t loop");
    vpColVector v;
    vpImage<vpRGBa> Ic;
    double lambda_av = 0.05;
    double alpha = 0.05;
    double beta = 3;

    for (;;) {
      std::cout << "---------------------------------------------" << iter << std::endl;

      try {
        g.acquire(I);
        vpDisplay::display(I);

        // Track the lines 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);
        }

        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();

        vpDisplay::flush(I);

        if (iter == 0)
          vpDisplay::getClick(I);
        if (v.sumSquare() > 0.5) {
          v = 0;
          robot.setVelocity(vpRobot::CAMERA_FRAME, v);
          robot.stopMotion();
          vpDisplay::getClick(I);
        }

        robot.setVelocity(vpRobot::CAMERA_FRAME, v);

      } catch (...) {
        v = 0;
        robot.setVelocity(vpRobot::CAMERA_FRAME, v);
        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