Visual Servoing Platform  version 3.5.1 under development (2022-11-27)

Example of eye-in-hand control law. We control here a real robot, the biclops robot (pan-tilt head provided by Traclabs). The velocity is computed in articular. The visual feature is the center of gravity of a point.

* ViSP, open source Visual Servoing Platform software.
* Copyright (C) 2005 - 2019 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.
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* GPL, please contact Inria about acquiring a ViSP Professional
* Edition License.
* See 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
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* This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
* Description:
* tests the control law
* eye-in-hand control
* velocity computed in articular
* Authors:
* Fabien Spindler
#include <signal.h>
#include <stdlib.h>
#include <visp3/core/vpConfig.h>
#include <visp3/core/vpDebug.h> // Debug trace
#include <visp3/core/vpTime.h>
#if (defined(VISP_HAVE_BICLOPS) && (defined(VISP_HAVE_DC1394) || defined(VISP_HAVE_DIRECTSHOW)))
#include <pthread.h>
#include <visp3/core/vpDisplay.h>
#include <visp3/core/vpImage.h>
#include <visp3/gui/vpDisplayGDI.h>
#include <visp3/gui/vpDisplayGTK.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/sensor/vp1394TwoGrabber.h>
#include <visp3/sensor/vpDirectShowGrabber.h>
#include <visp3/blob/vpDot.h>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/core/vpIoTools.h>
#include <visp3/core/vpMath.h>
#include <visp3/core/vpPoint.h>
#include <visp3/io/vpParseArgv.h>
#include <visp3/robot/vpRobotBiclops.h>
#include <visp3/visual_features/vpFeatureBuilder.h>
#include <visp3/visual_features/vpFeaturePoint.h>
#include <visp3/vs/vpServo.h>
#include <visp3/vs/vpServoDisplay.h>
// Exception
#include <visp3/core/vpException.h>
pthread_mutex_t mutexEndLoop = PTHREAD_MUTEX_INITIALIZER;
void signalCtrC(int /* signumber */)
vpTRACE("Ctrl-C pressed...");
// List of allowed command line options
#define GETOPTARGS "c:d:h"
void usage(const char *name, const char *badparam, std::string &conf, std::string &debugdir, std::string &user)
fprintf(stdout, "\n\
Example of eye-in-hand control law. We control here a real robot, the biclops\n\
robot (pan-tilt head provided by Traclabs). The velocity is\n\
computed in articular. The visual feature is the center of gravity of a\n\
%s [-c <Biclops configuration file>] [-d <debug file directory>] [-h]\n",
fprintf(stdout, "\n\
OPTIONS: Default\n\
-c <Biclops configuration file> %s\n\
Sets the biclops robot configuration file.\n\n\
-d <debug file directory> %s\n\
Sets the debug file directory.\n\
From this directory, creates the\"%s\"\n\
subdirectory depending on the username, where\n\
it writes biclops.txt file.\n",
conf.c_str(), debugdir.c_str(), user.c_str());
if (badparam) {
fprintf(stderr, "ERROR: \n");
fprintf(stderr, "\nBad parameter [%s]\n", badparam);
bool getOptions(int argc, const char **argv, std::string &conf, std::string &debugdir, std::string &user)
const char *optarg_;
int c;
while ((c = vpParseArgv::parse(argc, argv, GETOPTARGS, &optarg_)) > 1) {
switch (c) {
case 'c':
conf = optarg_;
case 'd':
debugdir = optarg_;
case 'h':
usage(argv[0], NULL, conf, debugdir, user);
return false;
usage(argv[0], optarg_, conf, debugdir, user);
return false;
if ((c == 1) || (c == -1)) {
// standalone param or error
usage(argv[0], NULL, conf, debugdir, user);
std::cerr << "ERROR: " << std::endl;
std::cerr << " Bad argument " << optarg_ << std::endl << std::endl;
return false;
return true;
int main(int argc, const char **argv)
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;
try {
signal(SIGINT, &signalCtrC);
// default unix configuration file path
std::string opt_conf = "/usr/share/BiclopsDefault.cfg";
std::string username;
std::string debugdir;
std::string opt_debugdir;
// Set the default output path
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
opt_debugdir = "/tmp";
#elif defined(_WIN32)
opt_debugdir = "C:/temp";
// Get the user login name
// Read the command line options
if (getOptions(argc, argv, opt_conf, opt_debugdir, username) == false) {
// Get the option value
if (!opt_debugdir.empty())
debugdir = opt_debugdir;
// Append to the output path string, the login name of the user
std::string dirname = debugdir + "/" + username;
// Test if the output path exist. If no try to create it
if (vpIoTools::checkDirectory(dirname) == false) {
try {
// Create the dirname
} catch (...) {
usage(argv[0], NULL, opt_conf, debugdir, username);
std::cerr << std::endl << "ERROR:" << std::endl;
std::cerr << " Cannot create " << dirname << std::endl;
std::cerr << " Check your -d " << debugdir << " option " << std::endl;
// Create the debug file: debugdir/$user/biclops.txt
char filename[FILENAME_MAX];
sprintf(filename, "%s/biclops.txt", debugdir.c_str());
FILE *fd = fopen(filename, "w");
vpRobotBiclops robot(opt_conf.c_str());
q = 0;
robot.setPosition(vpRobot::ARTICULAR_FRAME, q);
#if defined VISP_HAVE_DC1394
try {
} catch (...) {
vpERROR_TRACE(" Error caught");
return (-1);
// We open a window using either X11 or GTK or GDI.
// Its size is automatically defined by the image (I) size
#if defined VISP_HAVE_X11
vpDisplayX display(I, 100, 100, "Display X...");
#elif defined VISP_HAVE_GTK
vpDisplayGTK display(I, 100, 100, "Display GTK...");
#elif defined(_WIN32)
vpDisplayGDI display(I, 100, 100, "Display GDI...");
try {
} catch (...) {
vpERROR_TRACE(" Error caught");
return (-1);
vpServo task;
vpDot dot;
try {
std::cout << "Click on a dot to initialize the tracking..." << std::endl;
vpERROR_TRACE("after dot.initTracking(I) ");
} catch (...) {
vpERROR_TRACE(" Error caught");
return (-1);
// sets the current position of the visual feature
vpFeatureBuilder::create(p, cam, dot); // retrieve x,y and Z of the vpPoint structure
// sets the desired position of the visual feature
pd.buildFrom(0, 0, 1);
// define the task
// - we want an eye-in-hand control law
// - articular velocity are computed
vpTRACE("Set the position of the end-effector frame in the camera frame");
// robot.get_cMe(cMe) ;
std::cout << cVe << std::endl;
std::cout << "Click in the image to start the servoing..." << std::endl;
// Set the Jacobian (expressed in the end-effector frame)
vpMatrix eJe;
// we want to see a point on a point
task.addFeature(p, pd);
// set the gain
// Display task information
unsigned int iter = 0;
vpTRACE("\t loop");
while (0 != pthread_mutex_trylock(&mutexEndLoop))
for (;;)
std::cout << "---------------------------------------------" << iter << std::endl;
// vpDisplay::displayCross(I,(int)dot.I(), (int)dot.J(),
// 10,vpColor::green) ;
// get the jacobian
// std::cout << (vpMatrix)cVe*eJe << std::endl ;
v = task.computeControlLaw();
vpServoDisplay::display(task, cam, I);
std::cout << "v: " << v.t();
std::cout << "|| s - s* || = " << (task.getError()).sumSquare() << std::endl;
vpColVector s_minus_sStar(2);
s_minus_sStar = task.s - task.sStar;
fprintf(fd, "%f %f %f %f %f\n", v[0], v[1], s_minus_sStar[0], s_minus_sStar[1], (task.getError()).sumSquare());
std::cout << "Display task information " << std::endl;
} catch (const vpException &e) {
std::cout << "Catch an exception: " << e.getMessage() << std::endl;
int main()
std::cout << "You do not have an biclops PT robot connected to your computer..." << std::endl;
Class for firewire ieee1394 video devices using libdc1394-2.x api.
void acquire(vpImage< unsigned char > &I)
void open(vpImage< unsigned char > &I)
Generic class defining intrinsic camera parameters.
Implementation of column vector and the associated operations.
Definition: vpColVector.h:131
vpRowVector t() const
class for windows direct show devices
Display for windows using GDI (available on any windows 32 platform).
Definition: vpDisplayGDI.h:129
The vpDisplayGTK allows to display image using the GTK 3rd party library. Thus to enable this class G...
Definition: vpDisplayGTK.h:135
Use the X11 console to display images on unix-like OS. Thus to enable this class X11 should be instal...
Definition: vpDisplayX.h:135
static bool getClick(const vpImage< unsigned char > &I, bool blocking=true)
static void display(const vpImage< unsigned char > &I)
static void flush(const vpImage< unsigned char > &I)
This tracker is meant to track a dot (connected pixels with same gray level) on a vpImage.
Definition: vpDot.h:116
void initTracking(const vpImage< unsigned char > &I)
Definition: vpDot.cpp:635
void setGraphics(bool activate)
Definition: vpDot.h:361
void track(const vpImage< unsigned char > &I)
Definition: vpDot.cpp:770
error that can be emited by ViSP classes.
Definition: vpException.h:72
const char * getMessage() const
Definition: vpException.cpp:87
static void create(vpFeaturePoint &s, const vpCameraParameters &cam, const vpDot &d)
Class that defines a 2D point visual feature which is composed by two parameters that are the cartes...
void buildFrom(double x, double y, double Z)
void set_Z(double Z)
Implementation of an homogeneous matrix and operations on such kind of matrices.
static bool checkDirectory(const std::string &dirname)
Definition: vpIoTools.cpp:431
static std::string getUserName()
Definition: vpIoTools.cpp:327
static void makeDirectory(const std::string &dirname)
Definition: vpIoTools.cpp:581
Implementation of a matrix and operations on matrices.
Definition: vpMatrix.h:154
static bool parse(int *argcPtr, const char **argv, vpArgvInfo *argTable, int flags)
Definition: vpParseArgv.cpp:69
Interface for the biclops, pan, tilt head control.
void setVelocity(const vpRobot::vpControlFrameType frame, const vpColVector &vel)
void get_eJe(vpMatrix &eJe)
Definition: vpRobot.h:79
Initialize the position controller.
Definition: vpRobot.h:68
Initialize the velocity controller.
Definition: vpRobot.h:67
virtual vpRobotStateType setRobotState(const vpRobot::vpRobotStateType newState)
Definition: vpRobot.cpp:201
static void display(const vpServo &s, const vpCameraParameters &cam, const vpImage< unsigned char > &I, vpColor currentColor=vpColor::green, vpColor desiredColor=vpColor::red, unsigned int thickness=1)
void setInteractionMatrixType(const vpServoIteractionMatrixType &interactionMatrixType, const vpServoInversionType &interactionMatrixInversion=PSEUDO_INVERSE)
Definition: vpServo.cpp:564
Definition: vpServo.h:159
void set_cVe(const vpVelocityTwistMatrix &cVe_)
Definition: vpServo.h:448
void print(const vpServo::vpServoPrintType display_level=ALL, std::ostream &os=std::cout)
Definition: vpServo.cpp:303
void setLambda(double c)
Definition: vpServo.h:404
void set_eJe(const vpMatrix &eJe_)
Definition: vpServo.h:506
void setServo(const vpServoType &servo_type)
Definition: vpServo.cpp:215
vpColVector sStar
Definition: vpServo.h:563
vpColVector s
Definition: vpServo.h:559
vpColVector getError() const
Definition: vpServo.h:278
Definition: vpServo.h:202
vpColVector computeControlLaw()
Definition: vpServo.cpp:926
Definition: vpServo.h:186
void addFeature(vpBasicFeature &s, vpBasicFeature &s_star, unsigned int select=vpBasicFeature::FEATURE_ALL)
Definition: vpServo.cpp:487
vpVelocityTwistMatrix get_cVe() const
Definition: vpUnicycle.h:82
#define vpTRACE
Definition: vpDebug.h:416
#define vpERROR_TRACE
Definition: vpDebug.h:393
VISP_EXPORT int wait(double t0, double t)