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 abscise 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.

/****************************************************************************
 *
 * ViSP, open source Visual Servoing Platform software.
 * Copyright (C) 2005 - 2023 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 as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 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 https://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
 *
*****************************************************************************/
#include <iostream>
 
#include <visp3/core/vpConfig.h>
 
#include <visp3/blob/vpDot2.h>
#include <visp3/core/vpCameraParameters.h>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/core/vpImage.h>
#include <visp3/core/vpVelocityTwistMatrix.h>
#include <visp3/gui/vpDisplayGDI.h>
#include <visp3/gui/vpDisplayX.h> // Should be included after vpRobotPioneer.h
#include <visp3/gui/vpPlot.h>
#include <visp3/robot/vpPioneerPan.h>
#include <visp3/robot/vpRobotBiclops.h>
#include <visp3/robot/vpRobotPioneer.h> // Include first to avoid build issues with Status, None, isfinite
#include <visp3/sensor/vp1394CMUGrabber.h>
#include <visp3/sensor/vp1394TwoGrabber.h>
#include <visp3/sensor/vpV4l2Grabber.h>
#include <visp3/visual_features/vpFeatureBuilder.h>
#include <visp3/visual_features/vpFeatureSegment.h>
#include <visp3/vs/vpServo.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)
{
#ifdef ENABLE_VISP_NAMESPACE
  using namespace VISP_NAMESPACE_NAME;
#endif
 
#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
    // (around 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();
    return EXIT_SUCCESS;
  }
  catch (const vpException &e) {
    std::cout << "Catch an exception: " << e << std::endl;
    return EXIT_FAILURE;
  }
#endif
#endif
}
#else
int main()
{
  std::cout << "ViSP is not able to control the Pioneer robot" << std::endl;
  return EXIT_SUCCESS;
}
#endif