Visual Servoing Platform  version 3.5.1 under development (2022-10-03)
servoFlirPtuIBVS.cpp

Example of eye-in-hand image-based control law. We control here a real robot, the FLIR PTU that has 2 degrees of freedom. The velocity is computed in the joint space. Visual features are the image coordinates of the center of gravity of an AprilTag. The goal is here to center the tag in the image acquired from a FLIR camera mounted on the PTU.

Camera extrinsic (eMc) parameters are set by default to a value that will not match Your configuration. Use –eMc command line option to read the values from a file. This file could be obtained following extrinsic camera calibration tutorial: https://visp-doc.inria.fr/doxygen/visp-daily/tutorial-calibration-extrinsic.html

Camera intrinsic parameters are retrieved from the Realsense SDK.

The target is an AprilTag. It's size doesn't matter since we are using the center of gravity position.

/****************************************************************************
*
* 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.
*
* 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:
* Fabien Spindler
*
*****************************************************************************/
#include <iostream>
#include <visp3/core/vpCameraParameters.h>
#include <visp3/core/vpXmlParserCamera.h>
#include <visp3/detection/vpDetectorAprilTag.h>
#include <visp3/gui/vpDisplayGDI.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/gui/vpPlot.h>
#include <visp3/io/vpImageIo.h>
#include <visp3/robot/vpRobotFlirPtu.h>
#include <visp3/sensor/vpFlyCaptureGrabber.h>
#include <visp3/visual_features/vpFeatureBuilder.h>
#include <visp3/visual_features/vpFeaturePoint.h>
#include <visp3/vs/vpServo.h>
#include <visp3/vs/vpServoDisplay.h>
#if defined(VISP_HAVE_FLIR_PTU_SDK) && defined(VISP_HAVE_FLYCAPTURE) && \
(defined(VISP_HAVE_X11) || defined(VISP_HAVE_GDI))
void display_point_trajectory(const vpImage<unsigned char> &I, const vpImagePoint &ip,
std::vector<vpImagePoint> &traj_ip)
{
if (traj_ip.size()) {
// Add the point only if distance with the previous > 2 pixel
if (vpImagePoint::distance(ip, traj_ip.back()) > 2.) {
traj_ip.push_back(ip);
}
} else {
traj_ip.push_back(ip);
}
for (size_t j = 1; j < traj_ip.size(); j++) {
vpDisplay::displayLine(I, traj_ip[j - 1], traj_ip[j], vpColor::green, 2);
}
}
int main(int argc, char **argv)
{
std::string opt_portname;
int opt_baudrate = 9600;
bool opt_network = false;
std::string opt_extrinsic;
std::string opt_intrinsic;
std::string opt_camera_name;
bool display_tag = true;
int opt_quad_decimate = 2;
double opt_tag_size = 0.120; // Used to compute the distance of the cog wrt the camera
bool opt_verbose = false;
bool opt_plot = false;
bool opt_adaptive_gain = false;
bool opt_task_sequencing = false;
double opt_constant_gain = 0.5;
bool opt_display_trajectory = true;
double convergence_threshold = 0.00005;
if (argc == 1) {
std::cout << "To see how to use this example, run: " << argv[0] << " --help" << std::endl;
return EXIT_SUCCESS;
}
for (int i = 1; i < argc; i++) {
if ((std::string(argv[i]) == "--portname" || std::string(argv[i]) == "-p") && (i + 1 < argc)) {
opt_portname = std::string(argv[i + 1]);
} else if ((std::string(argv[i]) == "--baudrate" || std::string(argv[i]) == "-b") && (i + 1 < argc)) {
opt_baudrate = std::atoi(argv[i + 1]);
} else if ((std::string(argv[i]) == "--network" || std::string(argv[i]) == "-n")) {
opt_network = true;
} else if (std::string(argv[i]) == "--extrinsic" && i + 1 < argc) {
opt_extrinsic = std::string(argv[i + 1]);
} else if (std::string(argv[i]) == "--intrinsic" && i + 1 < argc) {
opt_intrinsic = std::string(argv[i + 1]);
} else if (std::string(argv[i]) == "--camera-name" && i + 1 < argc) {
opt_camera_name = std::string(argv[i + 1]);
} else if (std::string(argv[i]) == "--verbose" || std::string(argv[i]) == "-v") {
opt_verbose = true;
} else if (std::string(argv[i]) == "--plot" || std::string(argv[i]) == "-p") {
opt_plot = true;
} else if (std::string(argv[i]) == "--display-image-trajectory" || std::string(argv[i]) == "-traj") {
opt_display_trajectory = true;
} else if (std::string(argv[i]) == "--adaptive-gain" || std::string(argv[i]) == "-a") {
opt_adaptive_gain = true;
} else if (std::string(argv[i]) == "--constant-gain" || std::string(argv[i]) == "-g") {
opt_constant_gain = std::stod(argv[i + 1]);
} else if (std::string(argv[i]) == "--task-sequencing") {
opt_task_sequencing = true;
} else if (std::string(argv[i]) == "--quad-decimate" && i + 1 < argc) {
opt_quad_decimate = std::stoi(argv[i + 1]);
}
if (std::string(argv[i]) == "--tag-size" && i + 1 < argc) {
opt_tag_size = std::stod(argv[i + 1]);
} else if (std::string(argv[i]) == "--no-convergence-threshold") {
convergence_threshold = 0.;
} else if (std::string(argv[i]) == "--help" || std::string(argv[i]) == "-h") {
std::cout << "SYNOPSIS" << std::endl
<< " " << argv[0] << " [--portname <portname>] [--baudrate <rate>] [--network] "
<< "[--extrinsic <extrinsic.yaml>] [--intrinsic <intrinsic.xml>] [--camera-name <name>] "
<< "[--quad-decimate <decimation>] [--tag-size <size>] "
<< "[--adaptive-gain] [--constant-gain] [--display-image-trajectory] [--plot] [--task-sequencing] "
<< "[--no-convergence-threshold] [--verbose] [--help] [-h]" << std::endl
<< std::endl;
std::cout << "DESCRIPTION" << std::endl
<< " --portname, -p <portname>" << std::endl
<< " Set serial or tcp port name." << std::endl
<< std::endl
<< " --baudrate, -b <rate>" << std::endl
<< " Set serial communication baud rate. Default: " << opt_baudrate << "." << std::endl
<< std::endl
<< " --network, -n" << std::endl
<< " Get PTU network information (Hostname, IP, Gateway) and exit. " << std::endl
<< std::endl
<< " --reset, -r" << std::endl
<< " Reset PTU axis and exit. " << std::endl
<< std::endl
<< " --extrinsic <extrinsic.yaml>" << std::endl
<< " YAML file containing extrinsic camera parameters as a vpHomogeneousMatrix." << std::endl
<< " It corresponds to the homogeneous transformation eMc, between end-effector" << std::endl
<< " and camera frame." << std::endl
<< std::endl
<< " --intrinsic <intrinsic.xml>" << std::endl
<< " Intrinsic camera parameters obtained after camera calibration." << std::endl
<< std::endl
<< " --camera-name <name>" << std::endl
<< " Name of the camera to consider in the xml file provided for intrinsic camera parameters."
<< std::endl
<< std::endl
<< " --quad-decimate <decimation>" << std::endl
<< " Decimation factor used to detect AprilTag. Default " << opt_quad_decimate << "." << std::endl
<< std::endl
<< " --tag-size <size>" << std::endl
<< " Width in meter or the black part of the AprilTag used as target. Default " << opt_tag_size
<< "." << std::endl
<< std::endl
<< " --adaptive-gain, -a" << std::endl
<< " Enable adaptive gain instead of constant gain to speed up convergence. " << std::endl
<< std::endl
<< " --constant-gain, -g" << std::endl
<< " Constant gain value. Default value: " << opt_constant_gain << std::endl
<< std::endl
<< " --display-image-trajectory, -traj" << std::endl
<< " Display the trajectory of the target cog in the image. " << std::endl
<< std::endl
<< " --plot, -p" << std::endl
<< " Enable curve plotter. " << std::endl
<< std::endl
<< " --task-sequencing" << std::endl
<< " Enable task sequencing that allows to smoothly control the velocity of the robot. " << std::endl
<< std::endl
<< " --no-convergence-threshold" << std::endl
<< " Disable ending servoing when it reaches the desired position." << std::endl
<< std::endl
<< " --verbose, -v" << std::endl
<< " Additional printings. " << std::endl
<< std::endl
<< " --help, -h" << std::endl
<< " Print this helper message. " << std::endl
<< std::endl;
std::cout << "EXAMPLE" << std::endl
<< " - How to get network IP" << std::endl
#ifdef _WIN32
<< " $ " << argv[0] << " --portname COM1 --network" << std::endl
<< " Try to connect FLIR PTU to port: COM1 with baudrate: 9600" << std::endl
#else
<< " $ " << argv[0] << " -p /dev/ttyUSB0 --network" << std::endl
<< " Try to connect FLIR PTU to port: /dev/ttyUSB0 with baudrate: 9600" << std::endl
#endif
<< " PTU HostName: PTU-5" << std::endl
<< " PTU IP : 169.254.110.254" << std::endl
<< " PTU Gateway : 0.0.0.0" << std::endl
<< " - How to run this binary using network communication" << std::endl
<< " $ " << argv[0] << " --portname tcp:169.254.110.254 --tag-size 0.1 --gain 0.1" << std::endl;
return EXIT_SUCCESS;
}
}
try {
std::cout << "Try to connect FLIR PTU to port: " << opt_portname << " with baudrate: " << opt_baudrate << std::endl;
robot.connect(opt_portname, opt_baudrate);
if (opt_network) {
std::cout << "PTU HostName: " << robot.getNetworkHostName() << std::endl;
std::cout << "PTU IP : " << robot.getNetworkIP() << std::endl;
std::cout << "PTU Gateway : " << robot.getNetworkGateway() << std::endl;
return EXIT_SUCCESS;
}
g.open(I);
// Get camera extrinsics
eRc << 0, 0, 1, -1, 0, 0, 0, -1, 0;
etc << -0.1, -0.123, 0.035;
vpHomogeneousMatrix eMc(etc, eRc);
// If provided, read camera extrinsics from command line option
if (!opt_extrinsic.empty()) {
ePc.loadYAML(opt_extrinsic, ePc);
eMc.buildFrom(ePc);
} else {
std::cout << "***************************************************************" << std::endl;
std::cout << "Warning, use hard coded values for extrinsic camera parameters." << std::endl;
std::cout << "Create a yaml file that contains the extrinsic:" << std::endl
<< std::endl
<< "$ cat eMc.yaml" << std::endl
<< "rows: 4" << std::endl
<< "cols: 4" << std::endl
<< "data:" << std::endl
<< " - [0, 0, 1, -0.1]" << std::endl
<< " - [-1, 0, 0, -0.123]" << std::endl
<< " - [0, -1, 0, 0.035]" << std::endl
<< " - [0, 0, 0, 1]" << std::endl
<< std::endl
<< "and load this file with [--extrinsic <extrinsic.yaml] command line option, like:" << std::endl
<< std::endl
<< "$ " << argv[0] << "-p " << opt_portname << " --extrinsic eMc.yaml" << std::endl
<< std::endl;
std::cout << "***************************************************************" << std::endl;
}
std::cout << "Considered extrinsic transformation eMc:\n" << eMc << std::endl;
// Get camera intrinsics
vpCameraParameters cam(900, 900, I.getWidth() / 2., I.getHeight() / 2.);
// If provided, read camera intrinsics from command line option
if (!opt_intrinsic.empty() && !opt_camera_name.empty()) {
parser.parse(cam, opt_intrinsic, opt_camera_name, vpCameraParameters::perspectiveProjWithoutDistortion);
} else {
std::cout << "***************************************************************" << std::endl;
std::cout << "Warning, use hard coded values for intrinsic camera parameters." << std::endl;
std::cout << "Calibrate your camera and load the parameters from command line options, like:" << std::endl
<< std::endl
<< "$ " << argv[0] << "-p " << opt_portname << " --intrinsic camera.xml --camera-name \"Camera\""
<< std::endl
<< std::endl;
std::cout << "***************************************************************" << std::endl;
}
std::cout << "Considered intrinsic camera parameters:\n" << cam << "\n";
#if defined(VISP_HAVE_X11)
vpDisplayX dc(I, 10, 10, "Color image");
#elif defined(VISP_HAVE_GDI)
vpDisplayGDI dc(I, 10, 10, "Color image");
#endif
vpDetectorAprilTag detector(tagFamily);
detector.setAprilTagPoseEstimationMethod(poseEstimationMethod);
detector.setDisplayTag(display_tag);
detector.setAprilTagQuadDecimate(opt_quad_decimate);
// Create visual features
vpFeaturePoint p, pd; // We use 1 point, the tag cog
// Set desired position to the image center
pd.set_x(0);
pd.set_y(0);
vpServo task;
// Add the visual feature point
task.addFeature(p, pd);
if (opt_adaptive_gain) {
vpAdaptiveGain lambda(1.5, 0.4, 30); // lambda(0)=4, lambda(oo)=0.4 and lambda'(0)=30
task.setLambda(lambda);
} else {
task.setLambda(opt_constant_gain);
}
vpPlot *plotter = nullptr;
int iter_plot = 0;
if (opt_plot) {
plotter = new vpPlot(2, static_cast<int>(250 * 2), 500, static_cast<int>(I.getWidth()) + 80, 10,
"Real time curves plotter");
plotter->setTitle(0, "Visual features error");
plotter->setTitle(1, "Joint velocities");
plotter->initGraph(0, 2);
plotter->initGraph(1, 2);
plotter->setLegend(0, 0, "error_feat_p_x");
plotter->setLegend(0, 1, "error_feat_p_y");
plotter->setLegend(1, 0, "qdot_pan");
plotter->setLegend(1, 1, "qdot_tilt");
}
bool final_quit = false;
bool has_converged = false;
bool send_velocities = false;
bool servo_started = false;
std::vector<vpImagePoint> traj_cog;
vpMatrix eJe;
static double t_init_servo = vpTime::measureTimeMs();
robot.set_eMc(eMc); // Set location of the camera wrt end-effector frame
std::cout << cVe << std::endl;
task.set_cVe(cVe);
while (!has_converged && !final_quit) {
double t_start = vpTime::measureTimeMs();
g.acquire(I);
std::vector<vpHomogeneousMatrix> cMo_vec;
detector.detect(I, opt_tag_size, cam, cMo_vec);
std::stringstream ss;
ss << "Left click to " << (send_velocities ? "stop the robot" : "servo the robot") << ", right click to quit.";
vpDisplay::displayText(I, 20, 20, ss.str(), vpColor::red);
vpColVector qdot(2);
// Only one tag has to be detected
if (detector.getNbObjects() == 1) {
vpImagePoint cog = detector.getCog(0);
double Z = cMo_vec[0][2][3];
// Update current feature from measured cog position
double x = 0, y = 0;
if (opt_verbose) {
std::cout << "Z: " << Z << std::endl;
}
p.set_xyZ(x, y, Z);
pd.set_Z(Z);
// Get robot Jacobian
robot.get_eJe(eJe);
task.set_eJe(eJe);
if (opt_task_sequencing) {
if (!servo_started) {
if (send_velocities) {
servo_started = true;
}
t_init_servo = vpTime::measureTimeMs();
}
qdot = task.computeControlLaw((vpTime::measureTimeMs() - t_init_servo) / 1000.);
} else {
qdot = task.computeControlLaw();
}
// Display the current and desired feature points in the image display
// Display the trajectory of the points used as features
if (opt_display_trajectory) {
display_point_trajectory(I, cog, traj_cog);
}
if (opt_plot) {
plotter->plot(0, iter_plot, task.getError());
plotter->plot(1, iter_plot, qdot);
iter_plot++;
}
if (opt_verbose) {
std::cout << "qdot: " << qdot.t() << std::endl;
}
double error = task.getError().sumSquare();
ss.str("");
ss << "error: " << error;
vpDisplay::displayText(I, 20, static_cast<int>(I.getWidth()) - 150, ss.str(), vpColor::red);
if (opt_verbose)
std::cout << "error: " << error << std::endl;
if (error < convergence_threshold) {
has_converged = true;
std::cout << "Servo task has converged"
<< "\n";
vpDisplay::displayText(I, 100, 20, "Servo task has converged", vpColor::red);
}
} // end if (cMo_vec.size() == 1)
else {
qdot = 0;
}
if (!send_velocities) {
qdot = 0;
}
// Send to the robot
ss.str("");
ss << "Loop time: " << vpTime::measureTimeMs() - t_start << " ms";
vpDisplay::displayText(I, 40, 20, ss.str(), vpColor::red);
if (vpDisplay::getClick(I, button, false)) {
switch (button) {
send_velocities = !send_velocities;
break;
final_quit = true;
qdot = 0;
break;
default:
break;
}
}
}
std::cout << "Stop the robot " << std::endl;
if (opt_plot && plotter != nullptr) {
delete plotter;
plotter = nullptr;
}
if (!final_quit) {
while (!final_quit) {
g.acquire(I);
vpDisplay::displayText(I, 20, 20, "Click to quit the program.", vpColor::red);
vpDisplay::displayText(I, 40, 20, "Visual servo converged.", vpColor::red);
if (vpDisplay::getClick(I, false)) {
final_quit = true;
}
}
}
} catch (const vpRobotException &e) {
std::cout << "Catch Flir Ptu signal exception: " << e.getMessage() << std::endl;
} catch (const vpException &e) {
std::cout << "ViSP exception: " << e.what() << std::endl;
std::cout << "Stop the robot " << std::endl;
}
return EXIT_SUCCESS;
}
#else
int main()
{
#if !defined(VISP_HAVE_FLYCAPTURE)
std::cout << "Install FLIR Flycapture" << std::endl;
#endif
#if !defined(VISP_HAVE_FLIR_PTU_SDK)
std::cout << "Install FLIR PTU SDK." << std::endl;
#endif
return 0;
}
#endif
Adaptive gain computation.
static bool loadYAML(const std::string &filename, vpArray2D< Type > &A, char *header=NULL)
Definition: vpArray2D.h:652
Generic class defining intrinsic camera parameters.
Implementation of column vector and the associated operations.
Definition: vpColVector.h:131
double sumSquare() const
static const vpColor red
Definition: vpColor.h:217
static const vpColor green
Definition: vpColor.h:220
@ TAG_36h11
AprilTag 36h11 pattern (recommended)
Display for windows using GDI (available on any windows 32 platform).
Definition: vpDisplayGDI.h:129
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 displayLine(const vpImage< unsigned char > &I, const vpImagePoint &ip1, const vpImagePoint &ip2, const vpColor &color, unsigned int thickness=1, bool segment=true)
static void flush(const vpImage< unsigned char > &I)
static void displayText(const vpImage< unsigned char > &I, const vpImagePoint &ip, const std::string &s, const vpColor &color)
error that can be emited by ViSP classes.
Definition: vpException.h:72
const char * getMessage() const
Definition: vpException.cpp:87
const char * what() const
Definition: vpException.cpp:99
Class that defines a 2D point visual feature which is composed by two parameters that are the cartes...
void set_xyZ(double x, double y, double Z)
void set_y(double y)
void set_x(double x)
void set_Z(double Z)
void open(vpImage< unsigned char > &I)
void acquire(vpImage< unsigned char > &I)
Implementation of an homogeneous matrix and operations on such kind of matrices.
Class that defines a 2D point in an image. This class is useful for image processing and stores only ...
Definition: vpImagePoint.h:89
static double distance(const vpImagePoint &iP1, const vpImagePoint &iP2)
unsigned int getWidth() const
Definition: vpImage.h:246
unsigned int getHeight() const
Definition: vpImage.h:188
Implementation of a matrix and operations on matrices.
Definition: vpMatrix.h:154
static void convertPoint(const vpCameraParameters &cam, const double &u, const double &v, double &x, double &y)
This class enables real time drawing of 2D or 3D graphics. An instance of the class open a window whi...
Definition: vpPlot.h:116
void initGraph(unsigned int graphNum, unsigned int curveNbr)
Definition: vpPlot.cpp:205
void setLegend(unsigned int graphNum, unsigned int curveNum, const std::string &legend)
Definition: vpPlot.cpp:534
void plot(unsigned int graphNum, unsigned int curveNum, double x, double y)
Definition: vpPlot.cpp:285
void setTitle(unsigned int graphNum, const std::string &title)
Definition: vpPlot.cpp:497
Implementation of a pose vector and operations on poses.
Definition: vpPoseVector.h:152
Error that can be emited by the vpRobot class and its derivates.
void setVelocity(const vpRobot::vpControlFrameType frame, const vpColVector &vel)
void get_eJe(vpMatrix &eJe)
@ JOINT_STATE
Definition: vpRobot.h:81
@ STATE_VELOCITY_CONTROL
Initialize the velocity controller.
Definition: vpRobot.h:67
@ STATE_STOP
Stops robot motion especially in velocity and acceleration control.
Definition: vpRobot.h:66
virtual vpRobotStateType setRobotState(const vpRobot::vpRobotStateType newState)
Definition: vpRobot.cpp:201
Implementation of a rotation matrix and operations on such kind of matrices.
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
@ EYEINHAND_L_cVe_eJe
Definition: vpServo.h:159
void set_cVe(const vpVelocityTwistMatrix &cVe_)
Definition: vpServo.h:448
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 getError() const
Definition: vpServo.h:278
vpColVector computeControlLaw()
Definition: vpServo.cpp:926
@ CURRENT
Definition: vpServo.h:182
void addFeature(vpBasicFeature &s, vpBasicFeature &s_star, unsigned int select=vpBasicFeature::FEATURE_ALL)
Definition: vpServo.cpp:487
Class that consider the case of a translation vector.
vpVelocityTwistMatrix get_cVe() const
Definition: vpUnicycle.h:82
XML parser to load and save intrinsic camera parameters.
int parse(vpCameraParameters &cam, const std::string &filename, const std::string &camera_name, const vpCameraParameters::vpCameraParametersProjType &projModel, unsigned int image_width=0, unsigned int image_height=0)
VISP_EXPORT double measureTimeMs()