servoSimuCylinder2DCamVelocityDisplaySecondaryTask.cpp

Simulation of a 2D visual servoing:Simulation of a 2D visual servoing:

• servo on a cylinder,
• eye-in-hand control law,
• camera velocities are computed,
• display internal camera view and an external view.

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 - 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:
 * Simulation of a 2D visual servoing on a cylinder.
 *
 * Authors:
 * Nicolas Melchior
 *
 *****************************************************************************/
#include <visp3/core/vpConfig.h>

#if (defined (VISP_HAVE_X11) || defined(VISP_HAVE_GTK) || defined(VISP_HAVE_GDI) || defined(VISP_HAVE_OPENCV))

#include <stdlib.h>
#include <stdio.h>

#include <visp3/core/vpCameraParameters.h>
#include <visp3/core/vpCylinder.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/gui/vpDisplayGTK.h>
#include <visp3/gui/vpDisplayGDI.h>
#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/visual_features/vpFeatureBuilder.h>
#include <visp3/visual_features/vpFeatureLine.h>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/core/vpImage.h>
#include <visp3/core/vpMath.h>
#include <visp3/io/vpParseArgv.h>
#include <visp3/gui/vpProjectionDisplay.h>
#include <visp3/vs/vpServo.h>
#include <visp3/robot/vpSimulatorCamera.h>
#include <visp3/vs/vpServoDisplay.h>

// List of allowed command line options
#define GETOPTARGS  "cdh"

void usage(const char *name, const char *badparam);
bool getOptions(int argc, const char **argv, bool &click_allowed, bool &display);

void usage(const char *name, const char *badparam)
{
  fprintf(stdout, "\n\
Simulation of a 2D visual servoing on a cylinder:\n\
- eye-in-hand control law,\n\
- velocity computed in the camera frame,\n\
- display the camera view.\n\
          \n\
SYNOPSIS\n\
  %s [-c] [-d] [-h]\n", name);

  fprintf(stdout, "\n\
OPTIONS:                                               Default\n\
                  \n\
  -c\n\
     Disable the mouse click. Useful to automaze the \n\
     execution of this program without humain intervention.\n\
                  \n\
  -d \n\
     Turn off the display.\n\
                  \n\
  -h\n\
     Print the help.\n");

  if (badparam)
    fprintf(stdout, "\nERROR: Bad parameter [%s]\n", badparam);
}

bool getOptions(int argc, const char **argv, bool &click_allowed, bool &display)
{
  const char *optarg_;
  int   c;
  while ((c = vpParseArgv::parse(argc, argv, GETOPTARGS, &optarg_)) > 1) {

    switch (c) {
    case 'c': click_allowed = false; break;
    case 'd': display = false; break;
    case 'h': usage(argv[0], NULL); return false; break;

    default:
      usage(argv[0], optarg_);
      return false; break;
    }
  }

  if ((c == 1) || (c == -1)) {
    // standalone param or error
    usage(argv[0], NULL);
    std::cerr << "ERROR: " << std::endl;
    std::cerr << "  Bad argument " << optarg_ << std::endl << std::endl;
    return false;
  }

  return true;
}


int
main(int argc, const char ** argv)
{
  try {
    bool opt_display = true;
    bool opt_click_allowed = true;

    // Read the command line options
    if (getOptions(argc, argv, opt_click_allowed, opt_display) == false) {
      exit (-1);
    }

    vpImage<unsigned char> Iint(512,512,0) ;
    vpImage<unsigned char> Iext(512,512,0) ;

    // We open a window using either X11, GTK or GDI.
#if defined VISP_HAVE_X11
    vpDisplayX displayInt;
    vpDisplayX displayExt;
#elif defined VISP_HAVE_GTK
    vpDisplayGTK displayInt;
    vpDisplayGTK displayExt;
#elif defined VISP_HAVE_GDI
    vpDisplayGDI displayInt;
    vpDisplayGDI displayExt;
#elif defined VISP_HAVE_OPENCV
    vpDisplayOpenCV displayInt;
    vpDisplayOpenCV displayExt;
#endif

    if (opt_display) {
      try{
        // Display size is automatically defined by the image (Iint) and (Iext) size
        displayInt.init(Iint, 100, 100,"Internal view") ;
        displayExt.init(Iext, (int)(130+Iint.getWidth()), 100, "External view") ;
        // Display the image
        // The image class has a member that specify a pointer toward
        // the display that has been initialized in the display declaration
        // therefore is is no longuer necessary to make a reference to the
        // display variable.
        vpDisplay::display(Iint) ;
        vpDisplay::display(Iext) ;
        vpDisplay::flush(Iint) ;
        vpDisplay::flush(Iext) ;
      }
      catch(...)
      {
        vpERROR_TRACE("Error while displaying the image") ;
        exit(-1);
      }
    }

    vpProjectionDisplay externalview ;

    //Set the camera parameters
    double px, py ; px = py = 600 ;
    double u0, v0 ; u0 = v0 = 256 ;

    vpCameraParameters cam(px,py,u0,v0);

    vpServo task ;
    vpSimulatorCamera robot ;

    // sets the initial camera location
    vpHomogeneousMatrix cMo(-0.2,0.1,2,
                            vpMath::rad(5),  vpMath::rad(5),  vpMath::rad(20));

    vpHomogeneousMatrix wMc, wMo;
    robot.getPosition(wMc) ;
    wMo = wMc * cMo; // Compute the position of the object in the world frame

    // sets the final camera location (for simulation purpose)
    vpHomogeneousMatrix cMod(0,0,1,
                             vpMath::rad(0),  vpMath::rad(0),  vpMath::rad(0));

    // sets the cylinder coordinates in the world frame
    vpCylinder cylinder(0,1,0,  // direction
                        0,0,0,  // point of the axis
                        0.1) ;  // radius

    externalview.insert(cylinder) ;

    // sets the desired position of the visual feature
    cylinder.track(cMod) ;
    cylinder.print() ;

    //Build the desired line features thanks to the cylinder and especially its paramaters in the image frame
    vpFeatureLine ld[2] ;
    int i ;
    for(i=0 ; i < 2 ; i++)
      vpFeatureBuilder::create(ld[i],cylinder,i)  ;

    // computes  the cylinder coordinates in the camera frame and its 2D coordinates
    // sets the current position of the visual feature
    cylinder.track(cMo) ;
    cylinder.print() ;

    //Build the current line features thanks to the cylinder and especially its paramaters in the image frame
    vpFeatureLine l[2] ;
    for(i=0 ; i < 2 ; i++)
    {
      vpFeatureBuilder::create(l[i],cylinder,i)  ;
      l[i].print() ;
    }

    // define the task
    // - we want an eye-in-hand control law
    // - robot is controlled in the camera frame
    task.setServo(vpServo::EYEINHAND_CAMERA) ;
    task.setInteractionMatrixType(vpServo::DESIRED,vpServo::PSEUDO_INVERSE) ;
    //  it can also be interesting to test these possibilities
    // task.setInteractionMatrixType(vpServo::CURRENT,vpServo::PSEUDO_INVERSE) ;
    // task.setInteractionMatrixType(vpServo::MEAN, vpServo::PSEUDO_INVERSE) ;
    // task.setInteractionMatrixType(vpServo::CURRENT, vpServo::PSEUDO_INVERSE) ;
    // task.setInteractionMatrixType(vpServo::DESIRED,  vpServo::TRANSPOSE) ;
    // task.setInteractionMatrixType(vpServo::CURRENT,  vpServo::TRANSPOSE) ;

    // we want to see  2 lines on 2 lines
    task.addFeature(l[0],ld[0]) ;
    task.addFeature(l[1],ld[1]) ;

    // Set the point of view of the external view
    vpHomogeneousMatrix cextMo(0,0,6,
                               vpMath::rad(40),  vpMath::rad(10),  vpMath::rad(60))   ;

    // Display the initial scene
    vpServoDisplay::display(task,cam,Iint) ;
    externalview.display(Iext,cextMo, cMo, cam, vpColor::red);
    vpDisplay::flush(Iint) ;
    vpDisplay::flush(Iext) ;

    // Display task information
    task.print() ;

    if (opt_display && opt_click_allowed) {
      std::cout << "\n\nClick in the internal camera view window to start..." << std::endl;
      vpDisplay::getClick(Iint) ;
    }

    // set the gain
    task.setLambda(1) ;

    // Display task information
    task.print() ;

    unsigned int iter=0 ;
    // The first loop is needed to reach the desired position
    do
    {
      std::cout << "---------------------------------------------" << iter++ <<std::endl ;
      vpColVector v ;

      // get the robot position
      robot.getPosition(wMc) ;
      // Compute the position of the camera wrt the object frame
      cMo = wMc.inverse() * wMo;

      // new line position
      // retrieve x,y and Z of the vpLine structure
      // Compute the parameters of the cylinder in the camera frame and in the image frame
      cylinder.track(cMo) ;

      //Build the current line features thanks to the cylinder and especially its paramaters in the image frame
      for(i=0 ; i < 2 ; i++)
      {
        vpFeatureBuilder::create(l[i],cylinder,i)  ;
      }

      // Display the current scene
      if (opt_display) {
        vpDisplay::display(Iint) ;
        vpDisplay::display(Iext) ;
        vpServoDisplay::display(task,cam,Iint) ;
        externalview.display(Iext,cextMo, cMo, cam, vpColor::red);
        vpDisplay::flush(Iint);
        vpDisplay::flush(Iext);
      }

      // compute the control law
      v = task.computeControlLaw() ;

      // send the camera velocity to the controller
      robot.setVelocity(vpRobot::CAMERA_FRAME, v) ;

      std::cout << "|| s - s* || = " << ( task.getError() ).sumSquare() <<std::endl ;
    }
    while(( task.getError() ).sumSquare() >  1e-9) ;


    // Second loop is to compute the control law while taking into account the secondary task.
    // In this example the secondary task is cut in four steps.
    // The first one consists in impose a movement of the robot along the x axis of the object frame with a velocity of 0.5.
    // The second one consists in impose a movement of the robot along the y axis of the object frame with a velocity of 0.5.
    // The third one consists in impose a movement of the robot along the x axis of the object frame with a velocity of -0.5.
    // The last one consists in impose a movement of the robot along the y axis of the object frame with a velocity of -0.5.
    // Each steps is made during 200 iterations.
    vpColVector e1(6) ; e1 = 0 ;
    vpColVector e2(6) ; e2 = 0 ;
    vpColVector proj_e1 ;
    vpColVector proj_e2 ;
    iter = 0;
    double rapport = 0;
    double vitesse = 0.5;
    unsigned int tempo = 800;

    while(iter < tempo)
    {
      vpColVector v ;

      robot.getPosition(wMc) ;
      // Compute the position of the camera wrt the object frame
      cMo = wMc.inverse() * wMo;

      cylinder.track(cMo) ;

      for(i=0 ; i < 2 ; i++)
      {
        vpFeatureBuilder::create(l[i],cylinder,i)  ;
      }

      if (opt_display)
      {
        vpDisplay::display(Iint) ;
        vpDisplay::display(Iext) ;
        vpServoDisplay::display(task,cam,Iint) ;
        externalview.display(Iext,cextMo, cMo, cam, vpColor::red);
        vpDisplay::flush(Iint);
        vpDisplay::flush(Iext);
      }

      v = task.computeControlLaw() ;

      if ( iter%tempo < 200  /*&&  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%tempo < 400 &&  iter%tempo >= 200)
      {
        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 < 600 &&  iter%tempo >= 400)
      {
        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 < 800 &&  iter%tempo >= 600)
      {
        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);

      std::cout << "|| s - s* || = " << ( task.getError() ).sumSquare() <<std::endl ;

      iter++;
    }

    if (opt_display && opt_click_allowed) {
      std::cout << "\nClick in the internal camera view window to end..." << std::endl;
      vpDisplay::getClick(Iint) ;
    }

    // Display task information
    task.print() ;
    task.kill();
    return 0;
  }
  catch(vpException &e) {
    std::cout << "Catch a ViSP exception: " << e << std::endl;
    return 1;
  }
}

#else
#include <iostream>

int main()
{
  std::cout << "You do not have X11, GTK, GDI or OpenCV display functionalities..." << std::endl;
}

#endif