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 - 2023 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 https://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
 *
*****************************************************************************/
 
#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 {
    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(HAVE_OPENCV_HIGHGUI)
    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 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.setLikelihoodThresholdType(vpMe::NORMALIZED_THRESHOLD);
    me.setThreshold(15);
    me.setSampleStep(10);
 
    // Initialize the tracking of the two edges of the cylinder
    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 ");
    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];
    vpFeatureBuilder::create(pd[0], cyld, vpCylinder::line1);
    vpFeatureBuilder::create(pd[1], cyld, vpCylinder::line2);
 
    // 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");
    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(0.3);
 
    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 = 0.02;
    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);
        vpDisplay::display(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);
        }
 
        vpDisplay::flush(I);
 
        // 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.setVelocity(vpRobot::CAMERA_FRAME, v);
        robot.stopMotion();
        exit(1);
      }
 
      robot.setVelocity(vpRobot::CAMERA_FRAME, v);
      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);
        vpDisplay::display(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);
        }
 
        vpDisplay::flush(I);
 
        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;
        }
 
        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