Visual Servoing Platform  version 3.2.0 under development (2018-08-18)
servoViper850Point2DArtVelocity.cpp

Example of eye-in-hand control law. We control here a real robot, the Viper S850 Adept robot (arm with 6 degrees of freedom). The velocity is computed in articular. 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 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 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 articular
*
* Authors:
* Eric Marchand
* Fabien Spindler
*
*****************************************************************************/
#include <visp3/core/vpConfig.h>
#include <visp3/core/vpDebug.h> // Debug trace
#include <fstream>
#include <iostream>
#include <sstream>
#include <stdio.h>
#include <stdlib.h>
#if (defined(VISP_HAVE_VIPER850) && defined(VISP_HAVE_DC1394))
#include <visp3/core/vpDisplay.h>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/core/vpImage.h>
#include <visp3/core/vpIoTools.h>
#include <visp3/core/vpMath.h>
#include <visp3/core/vpPoint.h>
#include <visp3/gui/vpDisplayGTK.h>
#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/robot/vpRobotViper850.h>
#include <visp3/sensor/vp1394TwoGrabber.h>
#include <visp3/visual_features/vpFeatureBuilder.h>
#include <visp3/visual_features/vpFeaturePoint.h>
#include <visp3/vs/vpServo.h>
// Exception
#include <visp3/core/vpException.h>
#include <visp3/vs/vpServoDisplay.h>
#include <visp3/blob/vpDot2.h>
int main()
{
// Log file creation in /tmp/$USERNAME/log.dat
// This file contains by line:
// - the 6 computed joint 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());
try {
vpServo task;
bool reset = false;
vp1394TwoGrabber g(reset);
g.open(I);
g.acquire(I);
#ifdef VISP_HAVE_X11
vpDisplayX display(I, 800, 100, "Current image");
#elif defined(VISP_HAVE_OPENCV)
vpDisplayOpenCV display(I, 800, 100, "Current image");
#elif defined(VISP_HAVE_GTK)
vpDisplayGTK display(I, 800, 100, "Current image");
#endif
// exit(1) ;
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 joint space" << std::endl;
std::cout << " Use of the Afma6 robot " << std::endl;
std::cout << " task : servo a point " << std::endl;
std::cout << "-------------------------------------------------------" << std::endl;
std::cout << std::endl;
vpDot2 dot;
std::cout << "Click on a dot..." << std::endl;
dot.initTracking(I);
vpImagePoint cog = dot.getCog();
// Update camera parameters
robot.getCameraParameters(cam, I);
vpTRACE("sets the current position of the visual feature ");
vpFeatureBuilder::create(p, cam, dot); // retrieve x,y and Z of the vpPoint structure
p.set_Z(1);
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 articular velocity are computed");
vpTRACE("Set the position of the camera in the end-effector frame ");
// robot.get_cMe(cMe) ;
robot.get_cVe(cVe);
std::cout << cVe << std::endl;
task.set_cVe(cVe);
// vpDisplay::getClick(I) ;
vpTRACE("Set the Jacobian (expressed in the end-effector frame)");
vpMatrix eJe;
robot.get_eJe(eJe);
task.set_eJe(eJe);
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();
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);
cog = dot.getCog();
// Display a green cross at the center of gravity position in the image
// Update the point feature from the dot location
// Get the jacobian of the robot
robot.get_eJe(eJe);
// Update this jacobian in the task structure. It will be used to
// compute the velocity skew (as an articular velocity) qdot = -lambda *
// L^+ * cVe * eJe * (s-s*)
task.set_eJe(eJe);
// std::cout << (vpMatrix)cVe*eJe << std::endl ;
// 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
// Save velocities applied to the robot in the log file
// v[0], v[1], v[2] correspond to joint translation velocities in m/s
// v[3], v[4], v[5] correspond to joint 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
// 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
// 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()).t() << std::endl; // s-s* for point
// std::cout << "|| s - s* || = " << ( task.getError() ).sumSquare() <<
// std::endl;
}
flog.close(); // Close the log file
std::cout << "Display task information: " << std::endl;
task.print();
task.kill();
return EXIT_SUCCESS;
}
catch (const vpException &e) {
flog.close(); // Close the log file
std::cout << "Catch an exception: " << e.getMessage() << std::endl;
return EXIT_FAILURE;
}
}
#else
int main()
{
std::cout << "You do not have an Viper 850 robot connected to your computer..." << std::endl;
return EXIT_SUCCESS;
}
#endif