servoSimuFourPoints2DCamVelocity.cpp

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

• servo on 4 points,
• eye-in-hand control law,
• camera velocity are computed,
• no display.

Interaction matrix is computed as the mean of the current and desired interaction matrix.

/****************************************************************************
 *
 * This file is part of the ViSP software.
 * Copyright (C) 2005 - 2015 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 using 4 points as visual feature.
 *
 * Authors:
 * Eric Marchand
 * Fabien Spindler
 *
 *****************************************************************************/

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

#include <visp3/core/vpConfig.h>
#include <visp3/visual_features/vpFeatureBuilder.h>
#include <visp3/visual_features/vpFeaturePoint.h>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/core/vpMath.h>
#include <visp3/io/vpParseArgv.h>
#include <visp3/vs/vpServo.h>
#include <visp3/robot/vpSimulatorCamera.h>

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

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

void usage(const char *name, const char *badparam)
{
  fprintf(stdout, "\n\
Simulation of a 2D visual servoing:\n\
- servo on 4 points,\n\
- eye-in-hand control law,\n\
- articular velocity are computed,\n\
- without display.\n\
          \n\
SYNOPSIS\n\
  %s [-h]\n", name);

  fprintf(stdout, "\n\
OPTIONS:                                               Default\n\
                  \n\
  -h\n\
     Print the help.\n");

  if (badparam) {
     fprintf(stderr, "ERROR: \n" );
     fprintf(stderr, "\nBad parameter [%s]\n", badparam);
  }
}

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

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

    int i ;
    vpServo task ;
    vpSimulatorCamera robot ;


    std::cout << std::endl ;
    std::cout << "-------------------------------------------------------" << std::endl ;
    std::cout << " Test program for vpServo "  <<std::endl ;
    std::cout << " Eye-in-hand task control,  articular velocity are computed" << std::endl ;
    std::cout << " Simulation " << std::endl ;
    std::cout << " task : servo 4 points " << std::endl ;
    std::cout << "-------------------------------------------------------" << std::endl ;
    std::cout << std::endl ;

    // sets the initial camera location with respect to the object
    vpHomogeneousMatrix cMo ;
    cMo[0][3] = 0.1 ;
    cMo[1][3] = 0.2 ;
    cMo[2][3] = 2 ;

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

    // sets the point coordinates in the object frame
    vpPoint point[4] ;
    point[0].setWorldCoordinates(-1,-1,0) ;
    point[1].setWorldCoordinates(1,-1,0) ;
    point[2].setWorldCoordinates(1,1,0) ;
    point[3].setWorldCoordinates(-1,1,0) ;

    // computes  the point coordinates in the camera frame and its 2D coordinates
    for (i = 0 ; i < 4 ; i++)
      point[i].track(cMo) ;

    // sets the desired position of the point
    vpFeaturePoint p[4] ;
    for (i = 0 ; i < 4 ; i++)
      vpFeatureBuilder::create(p[i], point[i])  ;  //retrieve x,y and Z of the vpPoint structure

    // sets the desired position of the point
    vpFeaturePoint pd[4] ;

    pd[0].buildFrom(-0.1,-0.1, 1) ;
    pd[1].buildFrom( 0.1,-0.1, 1) ;
    pd[2].buildFrom( 0.1, 0.1, 1) ;
    pd[3].buildFrom(-0.1, 0.1, 1) ;

    // define the task
    // - we want an eye-in-hand control law
    // - articular velocity are computed
    task.setServo(vpServo::EYEINHAND_L_cVe_eJe) ;
    task.setInteractionMatrixType(vpServo::MEAN) ;

    // Set the position of the camera in the end-effector frame
    vpHomogeneousMatrix cMe ;
    vpVelocityTwistMatrix cVe(cMe) ;
    task.set_cVe(cVe) ;

    // Set the Jacobian (expressed in the end-effector frame)
    vpMatrix eJe ;
    robot.get_eJe(eJe) ;
    task.set_eJe(eJe) ;

    // we want to see a point on a point
    for (i = 0 ; i < 4 ; i++)
      task.addFeature(p[i],pd[i]) ;

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

    // Display task information
    task.print() ;

    unsigned int iter=0 ;
    // loop
    while(iter++<1500)
    {
      std::cout << "---------------------------------------------" << iter <<std::endl ;
      vpColVector v ;

      // Set the Jacobian (expressed in the end-effector frame)
      // since q is modified eJe is modified
      robot.get_eJe(eJe) ;
      task.set_eJe(eJe) ;

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

      // update new point position and corresponding features
      for (i = 0 ; i < 4 ; i++)
      {
        point[i].track(cMo) ;
        //retrieve x,y and Z of the vpPoint structure
        vpFeatureBuilder::create(p[i],point[i])  ;
      }
      // since vpServo::MEAN interaction matrix is used, we need also to update the desired features at each iteration
      pd[0].buildFrom(-0.1,-0.1, 1) ;
      pd[1].buildFrom( 0.1,-0.1, 1) ;
      pd[2].buildFrom( 0.1, 0.1, 1) ;
      pd[3].buildFrom(-0.1, 0.1, 1) ;

      // 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;
    }

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