Visual Servoing Platform  version 3.0.1
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servoAfma4Point2DCamVelocity.cpp

Example of eye-in-hand control law. We control here a real robot, the Afma4 robot (cylindrical robot, with 4 degrees of freedom). The velocity is computed in the camera frame. The visual feature is the center of gravity of a point.

/****************************************************************************
*
* 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:
* tests the control law
* eye-in-hand control
* velocity computed in the camera frame
*
* Authors:
* Eric Marchand
* Fabien Spindler
*
*****************************************************************************/
#include <visp3/core/vpConfig.h>
#include <visp3/core/vpDebug.h> // Debug trace
#include <stdlib.h>
#if (defined (VISP_HAVE_AFMA4) && defined (VISP_HAVE_DC1394))
#include <visp3/sensor/vp1394TwoGrabber.h>
#include <visp3/core/vpImage.h>
#include <visp3/core/vpImagePoint.h>
#include <visp3/core/vpDisplay.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/gui/vpDisplayGTK.h>
#include <visp3/core/vpMath.h>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/visual_features/vpFeaturePoint.h>
#include <visp3/core/vpPoint.h>
#include <visp3/vs/vpServo.h>
#include <visp3/visual_features/vpFeatureBuilder.h>
#include <visp3/robot/vpRobotAfma4.h>
#include <visp3/core/vpIoTools.h>
// Exception
#include <visp3/core/vpException.h>
#include <visp3/vs/vpServoDisplay.h>
#include <visp3/blob/vpDot.h>
int
main()
{
try {
// Log file creation in /tmp/$USERNAME/log.dat
// This file contains by line:
// - the 6 computed cam velocities (m/s, rad/s) to achieve the task
// - the 6 mesured joint velocities (m/s, rad/s)
// - the 6 mesured joint positions (m, rad)
// - the 2 values of s - s*
std::string username;
// Get the user login name
// Create a log filename to save velocities...
std::string logdirname;
logdirname ="/tmp/" + username;
// Test if the output path exist. If no try to create it
if (vpIoTools::checkDirectory(logdirname) == false) {
try {
// Create the dirname
}
catch (...) {
std::cerr << std::endl
<< "ERROR:" << std::endl;
std::cerr << " Cannot create " << logdirname << std::endl;
exit(-1);
}
}
std::string logfilename;
logfilename = logdirname + "/log.dat";
// Open the log file name
std::ofstream flog(logfilename.c_str());
vpRobotAfma4 robot ;
vpServo task ;
vp1394TwoGrabber g(false);
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
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 point " << std::endl ;
std::cout << "-------------------------------------------------------" << std::endl ;
std::cout << std::endl ;
vpDot dot ;
std::cout << "Click on a dot..." << std::endl;
dot.initTracking(I) ;
// Get the cog of the dot
vpImagePoint cog = dot.getCog();
vpTRACE("sets the current position of the visual feature ") ;
vpFeatureBuilder::create(p, cam, dot) ; //retrieve x,y and Z of the vpPoint structure
vpTRACE("sets the desired position of the visual feature ") ;
pd.buildFrom(0,0,1) ;
vpTRACE("define the task") ;
vpTRACE("\t we want an eye-in-hand control law") ;
vpTRACE("\t robot is controlled in the camera frame") ;
vpTRACE("\t we want to see a point on a point..") ;
std::cout << std::endl ;
task.addFeature(p,pd) ;
vpTRACE("\t set the gain") ;
task.setLambda(0.8) ;
vpTRACE("Display task information " ) ;
task.print() ;
robot.setRobotState(vpRobot::STATE_VELOCITY_CONTROL) ;
std::cout << "\nHit CTRL-C to stop the loop...\n" << std::flush;
for ( ; ; ) {
// Acquire a new image from the camera
g.acquire(I) ;
// Display this image
// Achieve the tracking of the dot in the image
dot.track(I) ;
// Get the cog of the dot
vpImagePoint cog = dot.getCog();
// Display a green cross at the center of gravity position in the image
// Update the point feature from the dot location
// Compute the visual servoing skew vector
v = task.computeControlLaw() ;
// Display the current and desired feature points in the image display
vpServoDisplay::display(task, cam, I) ;
// Apply the computed joint velocities to the robot
robot.setVelocity(vpRobot::CAMERA_FRAME, v) ;
// Save velocities applied to the robot in the log file
// v[0], v[1], v[2] correspond to camera translation velocities in m/s
// v[3], v[4], v[5] correspond to camera rotation velocities in rad/s
flog << v[0] << " " << v[1] << " " << v[2] << " "
<< v[3] << " " << v[4] << " " << v[5] << " ";
// Get the measured joint velocities of the robot
robot.getVelocity(vpRobot::ARTICULAR_FRAME, qvel);
// Save measured joint velocities of the robot in the log file:
// - qvel[0], qvel[1], qvel[2] correspond to measured joint translation
// velocities in m/s
// - qvel[3], qvel[4], qvel[5] correspond to measured joint rotation
// velocities in rad/s
flog << qvel[0] << " " << qvel[1] << " " << qvel[2] << " "
<< qvel[3] << " " << qvel[4] << " " << qvel[5] << " ";
// Get the measured joint positions of the robot
robot.getPosition(vpRobot::ARTICULAR_FRAME, q);
// Save measured joint positions of the robot in the log file
// - q[0], q[1], q[2] correspond to measured joint translation
// positions in m
// - q[3], q[4], q[5] correspond to measured joint rotation
// positions in rad
flog << q[0] << " " << q[1] << " " << q[2] << " "
<< q[3] << " " << q[4] << " " << q[5] << " ";
// Save feature error (s-s*) for the feature point. For this feature
// point, we have 2 errors (along x and y axis). This error is expressed
// in meters in the camera frame
flog << task.getError() << std::endl;
// Flush the display
}
flog.close() ; // Close the log file
// Display task information
task.print() ;
// Kill the task
task.kill();
return 0;
}
catch(vpException &e) {
std::cout << "Catch a ViSP exception: " << e << std::endl;
return 1;
}
}
#else
int
main()
{
vpERROR_TRACE("You do not have an afma4 robot or a firewire framegrabber connected to your computer...");
}
#endif