servoPioneerPanSegment3D.cpp

Example that shows how to control the Pioneer mobile robot by IBVS visual servoing with respect to a segment. The segment consists in two horizontal dots. The current visual features that are used are . The desired one are , with:

• the normalized abscisse of the point corresponding to segment
• the normalized segment length
• the segment orientation.

The degrees of freedom that are controlled are , the translational and rotational velocity of the mobile platform at point M located at the middle between the two wheels, the head pan velocity respectively.

The depth of the points is estimated from the surface of the blob.

/****************************************************************************
 *
 * 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:
 * IBVS on Pioneer P3DX mobile platform
 *
 * Authors:
 * Fabien Spindler
 *
 *****************************************************************************/
#include <iostream>

#include <visp3/core/vpConfig.h>

#include <visp3/robot/vpRobotPioneer.h> // Include before vpDisplayX to avoid build issues
#include <visp3/robot/vpRobotBiclops.h>
#include <visp3/core/vpCameraParameters.h>
#include <visp3/gui/vpDisplayGDI.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/blob/vpDot2.h>
#include <visp3/visual_features/vpFeatureBuilder.h>
#include <visp3/visual_features/vpFeatureSegment.h>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/core/vpImage.h>
#include <visp3/sensor/vp1394TwoGrabber.h>
#include <visp3/sensor/vp1394CMUGrabber.h>
#include <visp3/sensor/vpV4l2Grabber.h>
#include <visp3/robot/vpPioneerPan.h>
#include <visp3/gui/vpPlot.h>
#include <visp3/vs/vpServo.h>
#include <visp3/core/vpVelocityTwistMatrix.h>

#define USE_REAL_ROBOT
#define USE_PLOTTER
#undef VISP_HAVE_V4L2 // To use a firewire camera

#if defined(VISP_HAVE_PIONEER) && defined(VISP_HAVE_BICLOPS)
int main(int argc, char **argv)
{
#if defined(VISP_HAVE_DC1394) || defined(VISP_HAVE_V4L2) || defined(VISP_HAVE_CMU1394)
#if defined(VISP_HAVE_X11) || defined(VISP_HAVE_GDI)
  try {
    vpImage<unsigned char> I; // Create a gray level image container
    double lambda = 0.1;
    // Scale parameter used to estimate the depth Z of the blob from its surface
    //double coef = 0.9/14.85;  // At 0.9m, the blob has a surface of 14.85 (Logitec sphere)
    double coef = 1.2/13.0;  // At 1m, the blob has a surface of 11.3 (AVT Pike 032C)
    double L = 0.21; // 3D horizontal segment length
    double Z_d = 0.8; // Desired distance along Z between camera and segment
    bool normalized = true; // segment normilized features are used

    // Warning: To have a non singular task of rank 3, Y_d should be different from 0 so that
    // the optical axis doesn't intersect the horizontal segment
    double Y_d = -.11;   // Desired distance along Y between camera and segment.
    vpColVector qm(2); // Measured head position
    qm = 0;
    double qm_pan = 0; // Measured pan position (tilt is not handled in that example)

#ifdef USE_REAL_ROBOT
    // Initialize the biclops head

    vpRobotBiclops biclops("/usr/share/BiclopsDefault.cfg");
    biclops.setDenavitHartenbergModel(vpBiclops::DH1);

    // Move to the initial position
    vpColVector q(2);

    q=0;
    //  q[0] = vpMath::rad(63);
    //  q[1] = vpMath::rad(12); // introduce a tilt angle to compensate camera sphere tilt so that the camera is parallel to the plane

    biclops.setRobotState(vpRobot::STATE_POSITION_CONTROL) ;
    biclops.setPosition( vpRobot::ARTICULAR_FRAME, q );
    //biclops.setPositioningVelocity(50);
    biclops.getPosition(vpRobot::ARTICULAR_FRAME, qm);
    qm_pan = qm[0];

    // Now the head will be controlled in velocity
    biclops.setRobotState(vpRobot::STATE_VELOCITY_CONTROL) ;

    // Initialize the pioneer robot
    vpRobotPioneer pioneer;
    ArArgumentParser parser(&argc, argv);
    parser.loadDefaultArguments();

    // ArRobotConnector connects to the robot, get some initial data from it such as type and name,
    // and then loads parameter files for this robot.
    ArRobotConnector robotConnector(&parser, &pioneer);
    if(!robotConnector.connectRobot())
    {
      ArLog::log(ArLog::Terse, "Could not connect to the pioneer robot.");
      if(parser.checkHelpAndWarnUnparsed())
      {
        Aria::logOptions();
        Aria::exit(1);
      }
    }
    if (!Aria::parseArgs())
    {
      Aria::logOptions();
      Aria::shutdown();
      return false;
    }

    pioneer.useSonar(false); // disable the sonar device usage

    // Wait 3 sec to be sure that the low level Aria thread used to control
    // the robot is started. Without this delay we experienced a delay (arround 2.2 sec)
    // between the velocity send to the robot and the velocity that is really applied
    // to the wheels.
    sleep(3);

    std::cout << "Pioneer robot connected" << std::endl;
#endif

    vpPioneerPan robot_pan; // Generic robot that computes the velocities for the pioneer and the biclops head

    // Camera parameters. In this experiment we don't need a precise calibration of the camera
    vpCameraParameters cam;

    // Create the camera framegrabber
#if defined(VISP_HAVE_V4L2)
    // Create a grabber based on v4l2 third party lib (for usb cameras under Linux)
    vpV4l2Grabber g;
    g.setScale(1);
    g.setInput(0);
    g.setDevice("/dev/video1");
    g.open(I);
    // Logitec sphere parameters
    cam.initPersProjWithoutDistortion(558, 555, 312, 210);
#elif defined(VISP_HAVE_DC1394)
    // Create a grabber based on libdc1394-2.x third party lib (for firewire cameras under Linux)
    vp1394TwoGrabber g(false);
    g.setVideoMode(vp1394TwoGrabber::vpVIDEO_MODE_640x480_MONO8);
    g.setFramerate(vp1394TwoGrabber::vpFRAMERATE_30);
    // AVT Pike 032C parameters
    cam.initPersProjWithoutDistortion(800, 795, 320, 216);
#elif defined(VISP_HAVE_CMU1394)
    // Create a grabber based on CMU 1394 third party lib (for firewire cameras under windows)
    vp1394CMUGrabber g;
    g.setVideoMode(0, 5); // 640x480 MONO8
    g.setFramerate(4);    // 30 Hz
    g.open(I);
    // AVT Pike 032C parameters
    cam.initPersProjWithoutDistortion(800, 795, 320, 216);
#endif

    // Acquire an image from the grabber
    g.acquire(I);

    // Create an image viewer
#if defined(VISP_HAVE_X11)
    vpDisplayX d(I, 10, 10, "Current frame");
#elif defined(VISP_HAVE_GDI)
    vpDisplayGDI d(I, 10, 10, "Current frame");
#endif
    vpDisplay::display(I);
    vpDisplay::flush(I);

    // The 3D segment consists in two horizontal dots
    vpDot2 dot[2];
    for (int i=0; i <2; i++)
    {
      dot[i].setGraphics(true);
      dot[i].setComputeMoments(true);
      dot[i].setEllipsoidShapePrecision(0.);  // to track a blob without any constraint on the shape
      dot[i].setGrayLevelPrecision(0.9);  // to set the blob gray level bounds for binarisation
      dot[i].setEllipsoidBadPointsPercentage(0.5); // to be accept 50% of bad inner and outside points with bad gray level
      dot[i].initTracking(I);
      vpDisplay::flush(I);
    }

    vpServo task;
    task.setServo(vpServo::EYEINHAND_L_cVe_eJe) ;
    task.setInteractionMatrixType(vpServo::DESIRED, vpServo::PSEUDO_INVERSE) ;
    task.setLambda(lambda) ;
    vpVelocityTwistMatrix cVe ; // keep to identity
    cVe = robot_pan.get_cVe() ;
    task.set_cVe(cVe) ;

    std::cout << "cVe: \n" << cVe << std::endl;

    vpMatrix eJe;

    // Update the robot jacobian that depends on the pan position
    robot_pan.set_eJe(qm_pan);
    // Get the robot jacobian
    eJe = robot_pan.get_eJe() ;
    task.set_eJe(eJe) ;
    std::cout << "eJe: \n" << eJe << std::endl;

    // Define a 3D horizontal segment an its cordinates in the image plane
    vpPoint P[2];
    P[0].setWorldCoordinates(-L/2, 0, 0);
    P[1].setWorldCoordinates( L/2, 0, 0);
    // Define the desired camera position
    vpHomogeneousMatrix cMo(0, Y_d, Z_d, 0, 0, 0);  // Here we are in front of the segment
    for (int i=0; i <2; i++)
    {
      P[i].changeFrame(cMo);
      P[i].project(); // Here the x,y parameters obtained by perspective projection are computed
    }

    // Estimate the depth of the segment extremity points
    double surface[2];
    double Z[2]; // Depth of the segment points
    for (int i=0; i<2; i++)
    {
      // Surface of the blob estimated from the image moment m00 and converted in meters
      surface[i] = 1./sqrt(dot[i].m00/(cam.get_px()*cam.get_py()));

      // Initial depth of the blob
      Z[i] = coef * surface[i] ;
    }

    // Use here a feature segment builder
    vpFeatureSegment s_segment(normalized), s_segment_d(normalized); // From the segment feature we use only alpha
    vpFeatureBuilder::create(s_segment, cam, dot[0], dot[1]);
    s_segment.setZ1(Z[0]);
    s_segment.setZ2(Z[1]);
    // Set the desired feature
    vpFeatureBuilder::create(s_segment_d, P[0], P[1]);
    s_segment.setZ1( P[0].get_Z() ); // Desired depth
    s_segment.setZ2( P[1].get_Z() );

    task.addFeature(s_segment, s_segment_d,
                    vpFeatureSegment::selectXc() |
                    vpFeatureSegment::selectL() |
                    vpFeatureSegment::selectAlpha());

#ifdef USE_PLOTTER
    //Create a window (500 by 500) at position (700, 10) with two graphics
    vpPlot graph(2, 500, 500, 700, 10, "Curves...");

    //The first graphic contains 3 curve and the second graphic contains 3 curves
    graph.initGraph(0,3);
    graph.initGraph(1,3);
    graph.setTitle(0, "Velocities");
    graph.setTitle(1, "Error s-s*");
    graph.setLegend(0, 0, "vx");
    graph.setLegend(0, 1, "wz");
    graph.setLegend(0, 2, "w_pan");
    graph.setLegend(1, 0, "xm/l");
    graph.setLegend(1, 1, "1/l");
    graph.setLegend(1, 2, "alpha");
#endif

    vpColVector v; // vz, wx

    try
    {
      unsigned int iter = 0;
      while(1)
      {
#ifdef USE_REAL_ROBOT
        // Get the new pan position
        biclops.getPosition(vpRobot::ARTICULAR_FRAME, qm);
#endif
        qm_pan = qm[0];

        // Acquire a new image
        g.acquire(I);
        // Set the image as background of the viewer
        vpDisplay::display(I);

        // Display the desired position of the segment
        for (int i=0; i<2; i++)
          P[i].display(I, cam, vpColor::red, 3);

        // Does the blob tracking
        for (int i=0; i<2; i++)
          dot[i].track(I);

        for (int i=0; i<2; i++)
        {
          // Surface of the blob estimated from the image moment m00 and converted in meters
          surface[i] = 1./sqrt(dot[i].m00/(cam.get_px()*cam.get_py()));

          // Initial depth of the blob
          Z[i] = coef * surface[i] ;
        }

        // Update the features
        vpFeatureBuilder::create(s_segment, cam, dot[0], dot[1]);
        // Update the depth of the point. Useful only if current interaction matrix is used
        // when task.setInteractionMatrixType(vpServo::CURRENT, vpServo::PSEUDO_INVERSE) is set
        s_segment.setZ1(Z[0]);
        s_segment.setZ2(Z[1]);

        robot_pan.get_cVe(cVe);
        task.set_cVe(cVe);

        // Update the robot jacobian that depends on the pan position
        robot_pan.set_eJe(qm_pan);
        // Get the robot jacobian
        eJe = robot_pan.get_eJe();
        // Update the jacobian that will be used to compute the control law
        task.set_eJe(eJe);

        // Compute the control law. Velocities are computed in the mobile robot reference frame
        v = task.computeControlLaw();

        //      std::cout << "-----" << std::endl;
        //      std::cout << "v: " << v.t() << std::endl;
        //      std::cout << "error: " << task.getError().t() << std::endl;
        //      std::cout << "L:\n " << task.getInteractionMatrix() << std::endl;
        //      std::cout << "eJe:\n " << task.get_eJe() << std::endl;
        //      std::cout << "cVe:\n " << task.get_cVe() << std::endl;
        //      std::cout << "L_cVe_eJe:\n" << task.getInteractionMatrix() * task.get_cVe() * task.get_eJe() << std::endl;
        //      task.print() ;
        if (task.getTaskRank() != 3)
          std::cout << "Warning: task is of rank " << task.getTaskRank() << std::endl;

#ifdef USE_PLOTTER
        graph.plot(0, iter, v); // plot velocities applied to the robot
        graph.plot(1, iter, task.getError()); // plot error vector
#endif

#ifdef USE_REAL_ROBOT
        // Send the velocity to the robot
        vpColVector v_pioneer(2); // vx, wz
        v_pioneer[0] = v[0];
        v_pioneer[1] = v[1];
        vpColVector v_biclops(2); // qdot pan and tilt
        v_biclops[0] = v[2];
        v_biclops[1] = 0;

        std::cout << "Send velocity to the pionner: " << v_pioneer[0] << " m/s "
                  << vpMath::deg(v_pioneer[1]) << " deg/s" << std::endl;
        std::cout << "Send velocity to the biclops head: " << vpMath::deg(v_biclops[0]) << " deg/s" << std::endl;

        pioneer.setVelocity(vpRobot::REFERENCE_FRAME, v_pioneer);
        biclops.setVelocity(vpRobot::ARTICULAR_FRAME, v_biclops) ;
#endif

        // Draw a vertical line which corresponds to the desired x coordinate of the dot cog
        vpDisplay::displayLine(I, 0, cam.get_u0(), 479, cam.get_u0(), vpColor::red);
        vpDisplay::flush(I);

        // A click in the viewer to exit
        if ( vpDisplay::getClick(I, false) )
          break;

        iter ++;
        //break;
      }
    }
    catch(...)
    {
    }

#ifdef USE_REAL_ROBOT
    std::cout << "Ending robot thread..." << std::endl;
    pioneer.stopRunning();

    // wait for the thread to stop
    pioneer.waitForRunExit();
#endif

    // Kill the servo task
    task.print() ;
    task.kill();
  }
  catch(vpException &e) {
    std::cout << "Catch an exception: " << e << std::endl;
    return 1;
  }
#endif
#endif
}
#else
int main()
{
  std::cout << "ViSP is not able to control the Pioneer robot" << std::endl;
  return 0;
}
#endif