Visual Servoing Platform  version 3.5.1 under development (2022-07-05)

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. The used visual feature is a circle.

* 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
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* Campus Universitaire de Beaulieu
* 35042 Rennes Cedex
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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 the camera frame
* Authors:
* Eric Marchand
#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/gui/vpDisplayGTK.h>
#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/sensor/vp1394TwoGrabber.h>
#include <visp3/core/vpHomogeneousMatrix.h>
#include <visp3/core/vpMath.h>
#include <visp3/visual_features/vpFeatureBuilder.h>
#include <visp3/visual_features/vpFeatureEllipse.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/vpDot.h>
int main()
try {
vpServo task;;
#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");
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;
dot.setMaxDotSize(0.30); // Max dot size is 30 % of the image size
// dot.setGraphics(true) ;
std::cout << "Click on an ellipse..." << std::endl;
vpImagePoint cog = dot.getCog();
vpRobotAfma6 robot;
// Update camera parameters
robot.getCameraParameters(cam, I);
vpTRACE("sets the current position of the visual feature ");
std::cout << " Learning 0/1 " << std::endl;
int learning;
std::cin >> learning;
char name[FILENAME_MAX];
sprintf(name, "dat/ellipse.dat");
if (learning == 1) {
// save the object position
vpTRACE("Save the location of the object in a file dat/ellipse.dat");
std::ofstream f(name);
f << c.get_s().t();
vpTRACE("sets the desired position of the visual feature ");
std::ifstream f("dat/ellipse.dat");
double x, y, n20, n11, n02;
f >> x;
f >> y;
f >> n20;
f >> n11;
f >> n02;
cd.buildFrom(x, y, n20, n11, n02);
cd.setABC(0, 0, 10);
task.addFeature(c, cd);
unsigned int iter = 0;
double lambda_av = 0.01;
double alpha = 0.1; // 1 ;
double beta = 3; // 3 ;
std::cout << "alpha 0.7" << std::endl;
std::cin >> alpha;
std::cout << "beta 5" << std::endl;
std::cin >> beta;
for (;;) {
std::cout << "---------------------------------------------" << iter++ << std::endl;
// Get the dot cog
cog = dot.getCog();
// Compute the adaptative gain (speed up the convergence)
double gain;
if (iter > 2) {
if (std::fabs(alpha) <= std::numeric_limits<double>::epsilon())
gain = lambda_av;
else {
gain = alpha * exp(-beta * (task.getError()).sumSquare()) + lambda_av;
} else
gain = lambda_av;
vpTRACE("%f %f", (task.getError()).sumSquare(), gain);
v = task.computeControlLaw();
std::cout << "rank " << task.getTaskRank() << std::endl;
vpServoDisplay::display(task, cam, I);
std::cout << v.t();
vpTRACE("\t\t || s - s* || = %f ", (task.getError()).sumSquare());
vpTRACE("Display task information ");
} catch (const vpException &e) {
std::cout << "Test failed with exception: " << e << std::endl;
int main()
std::cout << "You do not have an afma6 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 setVideoMode(vp1394TwoVideoModeType videomode)
void setFramerate(vp1394TwoFramerateType fps)
void open(vpImage< unsigned char > &I)
vpColVector get_s(unsigned int select=FEATURE_ALL) const
Get the feature vector .
Generic class defining intrinsic camera parameters.
Implementation of column vector and the associated operations.
Definition: vpColVector.h:131
vpRowVector t() const
static const vpColor blue
Definition: vpColor.h:223
static const vpColor green
Definition: vpColor.h:220
The vpDisplayGTK allows to display image using the GTK 3rd party library. Thus to enable this class G...
Definition: vpDisplayGTK.h:135
The vpDisplayOpenCV allows to display image using the OpenCV library. Thus to enable this class OpenC...
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 void display(const vpImage< unsigned char > &I)
static void displayCross(const vpImage< unsigned char > &I, const vpImagePoint &ip, unsigned int size, const vpColor &color, unsigned int thickness=1)
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 setMaxDotSize(double percentage)
Definition: vpDot.cpp:601
void initTracking(const vpImage< unsigned char > &I)
Definition: vpDot.cpp:635
void setComputeMoments(bool activate)
Definition: vpDot.h:337
vpImagePoint getCog() const
Definition: vpDot.h:247
void track(const vpImage< unsigned char > &I)
Definition: vpDot.cpp:770
error that can be emited by ViSP classes.
Definition: vpException.h:72
static void create(vpFeaturePoint &s, const vpCameraParameters &cam, const vpDot &d)
Class that defines 2D ellipse visual feature.
void setABC(double A, double B, double C)
void buildFrom(double x, double y, double n20, double n11, double n02)
Class that defines a 2D point in an image. This class is useful for image processing and stores only ...
Definition: vpImagePoint.h:89
Control of Irisa's gantry robot named Afma6.
Definition: vpRobotAfma6.h:212
void setVelocity(const vpRobot::vpControlFrameType frame, const vpColVector &vel)
Definition: vpRobot.h:83
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:155
unsigned int getTaskRank() const
Definition: vpServo.cpp:1783
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 setServo(const vpServoType &servo_type)
Definition: vpServo.cpp:215
vpColVector getError() const
Definition: vpServo.h:278
Definition: vpServo.h:202
vpColVector computeControlLaw()
Definition: vpServo.cpp:926
Definition: vpServo.h:182
void addFeature(vpBasicFeature &s, vpBasicFeature &s_star, unsigned int select=vpBasicFeature::FEATURE_ALL)
Definition: vpServo.cpp:487
#define vpTRACE
Definition: vpDebug.h:416