Visual Servoing Platform  version 3.2.0 under development (2018-10-24)
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.

/****************************************************************************
*
* 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 the camera frame
*
* Authors:
* Nicolas Melchior
*
*****************************************************************************/
#include <cmath> // std::fabs
#include <limits> // numeric_limits
#include <stdlib.h>
#include <visp3/core/vpConfig.h>
#include <visp3/core/vpDebug.h> // Debug trace
#if (defined(VISP_HAVE_AFMA6) && defined(VISP_HAVE_DC1394))
#include <visp3/core/vpDisplay.h>
#include <visp3/core/vpImage.h>
#include <visp3/core/vpImagePoint.h>
#include <visp3/gui/vpDisplayGTK.h>
#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/io/vpImageIo.h>
#include <visp3/sensor/vp1394TwoGrabber.h>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/core/vpLine.h>
#include <visp3/core/vpMath.h>
#include <visp3/vision/vpPose.h>
#include <visp3/visual_features/vpFeatureBuilder.h>
#include <visp3/visual_features/vpFeatureDepth.h>
#include <visp3/visual_features/vpFeatureLine.h>
#include <visp3/visual_features/vpFeaturePoint.h>
#include <visp3/visual_features/vpGenericFeature.h>
#include <visp3/vs/vpServo.h>
#include <visp3/robot/vpRobotAfma6.h>
// Exception
#include <visp3/core/vpException.h>
#include <visp3/vs/vpServoDisplay.h>
#include <visp3/blob/vpDot2.h>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/core/vpPoint.h>
int main()
{
try {
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
vpServo task;
vpRobotAfma6 robot;
// robot.move("zero.pos") ;
// 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
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);
vpTRACE("Initialization of the tracking");
vpMeLine line[nbline];
vpPoint point[nbpoint];
int i;
vpMe me;
me.setRange(10);
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
for (i = 0; i < nbline; i++) {
double x = 0, y = 0;
if (!vpMeLine::intersection(line[i % nbline], line[(i + 1) % nbline], ip)) {
exit(-1);
}
point[i].set_x(x);
point[i].set_y(y);
}
// Compute the pose cMo
vpPose pose;
pose.clearPoint();
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
}
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);
pointc.project(cMo);
// The second feature is the depth of the current square center relative
// to the depth of the desired square center.
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.
cdMc = cMod * cMo.inverse();
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");
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();
unsigned int iter = 0;
vpTRACE("\t loop");
double lambda_av = 0.05;
double alpha = 0.05;
double beta = 3;
for (;;) {
std::cout << "---------------------------------------------" << iter << std::endl;
try {
g.acquire(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);
}
point[i].set_x(x);
point[i].set_y(y);
pose.addPoint(point[i]);
}
// Compute the pose
// 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);
// 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();
std::cout << v.sumSquare() << std::endl;
if (iter == 0)
if (v.sumSquare() > 0.5) {
v = 0;
robot.stopMotion();
}
} catch (...) {
v = 0;
robot.stopMotion();
exit(1);
}
vpTRACE("\t\t || s - s* || = %f ", (task.getError()).sumSquare());
iter++;
}
vpTRACE("Display task information ");
task.print();
task.kill();
return EXIT_SUCCESS;
}
catch (const vpException &e) {
std::cout << "Test failed with exception: " << e << std::endl;
return EXIT_FAILURE;
}
}
#else
int main()
{
std::cout << "You do not have an afma6 robot connected to your computer..." << std::endl;
return EXIT_SUCCESS;
}
#endif