servoSimuPoint2DCamVelocity2.cpp

Servo a point:

• eye-in-hand control law,
• velocity computed in the camera frame,
• no display.

wrt. servoSimuPoint2DCamVelocity1.cpp only the type of control law is modified. This illustrates the need for Jacobian update and Twist transformation matrix initialization.

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 - 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 point.
 *
 * Authors:
 * Eric Marchand
 * Fabien Spindler
 *
 *****************************************************************************/

#include <stdlib.h>
#include <stdio.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 on a point:\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(stdout, "\nERROR: Bad 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);
    }

    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 a point " << std::endl ;
    std::cout << "-------------------------------------------------------" << std::endl ;
    std::cout << std::endl ;

    // sets the initial camera location
    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 world frame
    vpPoint point(0, 0, 0);

    // computes the point coordinates in the camera frame and its 2D coordinates
    point.track(cMo);

    // sets the current position of the visual feature
    vpFeaturePoint p;
    vpFeatureBuilder::create(p, point);  //retrieve x,y and Z of the vpPoint structure

    // sets the desired position of the visual feature
    vpFeaturePoint pd;
    pd.buildFrom(0,0,1);

    // 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
    task.addFeature(p,pd) ;

    // set the gain
    task.setLambda(1) ;
    // Display task information
    task.print() ;

    unsigned int iter=0 ;
    // loop
    while(iter++<100)
    {
      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;

      // new point position
      point.track(cMo) ;
      vpFeatureBuilder::create(p,point)  ;  //retrieve x,y and Z of the vpPoint structure
      pd.buildFrom(0,0,1) ; // Since vpServo::MEAN interaction matrix is used, we need to update the desired feature at each iteration

      // 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;
  }
}