servoAfma62DhalfCamVelocity.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 given thanks to four lines and are the x and y coordinates of the rectangle center, log(Z/Z*) the current depth relative to the desired depth and the thetau rotations.

/****************************************************************************
 *
 * $Id: servoAfma62DhalfCamVelocity.cpp 4056 2013-01-05 13:04:42Z fspindle $
 *
 * This file is part of the ViSP software.
 * Copyright (C) 2005 - 2013 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://www.irisa.fr/lagadic/visp/visp.html for more information.
 * 
 * This software was developed at:
 * INRIA Rennes - Bretagne Atlantique
 * Campus Universitaire de Beaulieu
 * 35042 Rennes Cedex
 * France
 * http://www.irisa.fr/lagadic
 *
 * 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:
 * Nicolas Melchior
 *
 *****************************************************************************/
#include <visp/vpConfig.h>
#include <visp/vpDebug.h> // Debug trace
#include <stdlib.h>
#include <cmath>    // std::fabs
#include <limits>   // numeric_limits
#if (defined (VISP_HAVE_AFMA6) && defined (VISP_HAVE_DC1394_2))

#include <visp/vp1394TwoGrabber.h>
#include <visp/vpImage.h>
#include <visp/vpImagePoint.h>
#include <visp/vpImageIo.h>
#include <visp/vpDisplay.h>
#include <visp/vpDisplayX.h>
#include <visp/vpDisplayOpenCV.h>
#include <visp/vpDisplayGTK.h>

#include <visp/vpMath.h>
#include <visp/vpHomogeneousMatrix.h>
#include <visp/vpFeatureLine.h>
#include <visp/vpFeaturePoint.h>
#include <visp/vpFeatureDepth.h>
#include <visp/vpGenericFeature.h>
#include <visp/vpLine.h>
#include <visp/vpServo.h>
#include <visp/vpFeatureBuilder.h>
#include <visp/vpPose.h>

#include <visp/vpRobotAfma6.h>

// Exception
#include <visp/vpException.h>
#include <visp/vpMatrixException.h>
#include <visp/vpServoDisplay.h>

#include <visp/vpDot2.h>
#include <visp/vpPoint.h>
#include <visp/vpHomogeneousMatrix.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 ;

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

    vpCameraParameters cam ;
    // Update camera parameters
    robot.getCameraParameters (cam, I);


    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 nbline =4 ;
    int nbpoint =4 ;


    vpTRACE("sets the desired position of the visual feature ") ;
    vpPoint pointd[nbpoint];  //position of the fours corners
    vpPoint pointcd;  //position of the center of the square
    vpFeaturePoint pd;

    double L=0.05 ;
    pointd[0].setWorldCoordinates(L,-L, 0 ) ;
    pointd[1].setWorldCoordinates(L,L, 0 ) ;
    pointd[2].setWorldCoordinates(-L,L, 0 ) ;
    pointd[3].setWorldCoordinates(-L,-L, 0 ) ;

    //The coordinates in the object frame of the point used as a feature ie the center of the square
    pointcd.setWorldCoordinates(0, 0, 0 ) ;

    //The desired homogeneous matrix.
    vpHomogeneousMatrix cMod(0,0,0.4,0,0,vpMath::rad(10));

    pointd[0].project(cMod);
    pointd[1].project(cMod);
    pointd[2].project(cMod);
    pointd[3].project(cMod);

    pointcd.project(cMod);

    vpFeatureBuilder::create(pd,pointcd);

    vpTRACE("Initialization of the tracking") ;
    vpMeLine line[nbline] ;
    vpPoint point[nbpoint];
    int i ;

    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].setMe(&me) ;

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

    // Compute the position of the four corners. The goal is to
    // compute the pose
    vpImagePoint ip;
    for (i=0 ; i < nbline ; i++)
    {
      double x=0, y=0;

      if (!vpMeLine::intersection (line[i%nbline], line[(i+1)%nbline], ip))
      {
        exit(-1);
      }

      vpPixelMeterConversion::convertPoint(cam, ip, x, y)  ;

      point[i].set_x(x) ;
      point[i].set_y(y) ;
    }

    //Compute the pose cMo
    vpPose pose ;
    pose.clearPoint() ;
    vpHomogeneousMatrix cMo ;

    point[0].setWorldCoordinates(L,-L, 0 ) ;
    point[1].setWorldCoordinates(L,L, 0 ) ;
    point[2].setWorldCoordinates(-L,L, 0 ) ;
    point[3].setWorldCoordinates(-L,-L, 0 ) ;

    for (i=0 ; i < nbline ; i++)
    {
      pose.addPoint(point[i]) ; // and added to the pose computation point list
    }

    pose.computePose(vpPose::LAGRANGE, cMo) ;
    pose.computePose(vpPose::VIRTUAL_VS, cMo);


    vpTRACE("sets the current position of the visual feature ") ;

    //The first features are the position in the camera frame x and y of the square center
    vpPoint pointc; //The current position of the center of the square
    double xc = (point[0].get_x()+point[2].get_x())/2;
    double yc = (point[0].get_y()+point[2].get_y())/2;
    pointc.set_x(xc);
    pointc.set_y(yc);
    vpFeaturePoint p;
    pointc.project(cMo);
    vpFeatureBuilder::create(p,pointc);

    //The second feature is the depth of the current square center relative to the depth of the desired square center.
    vpFeatureDepth logZ;
    logZ.buildFrom(pointc.get_x(), pointc.get_y(), pointc.get_Z(), log(pointc.get_Z()/pointcd.get_Z()));

    //The last three features are the rotations thetau between the current pose and the desired pose.
    vpHomogeneousMatrix cdMc ;
    cdMc = cMod*cMo.inverse() ;
    vpFeatureThetaU tu(vpFeatureThetaU::cdRc);
    tu.buildFrom(cdMc) ;

    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::CURRENT, vpServo::PSEUDO_INVERSE);

    vpTRACE("\t we want to see a point on a point..") ;
    std::cout << std::endl ;
    task.addFeature(p,pd) ;
    task.addFeature(logZ) ;
    task.addFeature(tu);


    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) ;

        pose.clearPoint() ;

        //Track the lines and find the current position of the corners
        for (i=0 ; i < nbline ; i++)
        {
              line[i].track(I) ;

              line[i].display(I,vpColor::green);

          double x=0, y=0;

          if (!vpMeLine::intersection (line[i%nbline], line[(i+1)%nbline], ip))
          {
            exit(-1);
          }

              vpPixelMeterConversion::convertPoint(cam, ip, x, y)  ;

          point[i].set_x(x);
          point[i].set_y(y);

              pose.addPoint(point[i]) ;
        }

        //Compute the pose
        pose.computePose(vpPose::VIRTUAL_VS, cMo) ;

        //Update the two first features x and y (position of the square center)
        xc = (point[0].get_x()+point[2].get_x())/2;
        yc = (point[0].get_y()+point[2].get_y())/2;
        pointc.set_x(xc);
        pointc.set_y(yc);
        pointc.project(cMo);
        vpFeatureBuilder::create(p,pointc);
        //Print the current and the desired position of the center of the square
        //Print the desired position of the four corners
        p.display(cam, I,  vpColor::green) ;
        pd.display(cam, I,  vpColor::red) ;
        for (i = 0; i < nbpoint; i++) pointd[i].display(I, cam, vpColor::red);

        //Update the second feature
        logZ.buildFrom(pointc.get_x(), pointc.get_y(), pointc.get_Z(), log(pointc.get_Z()/pointcd.get_Z()));

        //Update the last three features
        cdMc = cMod*cMo.inverse() ;
        tu.buildFrom(cdMc) ;

        //Adaptive 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() ;

        vpDisplay::flush(I) ;
        std::cout << v.sumSquare() <<std::endl  ;
        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() ;
    task.kill();
  }
  catch (...)
  {
    vpERROR_TRACE(" Test failed") ;
    return 0;
  }
}

#else
int
main()
{
  vpERROR_TRACE("You do not have an afma6 robot or a firewire framegrabber connected to your computer...");
}

#endif