Visual Servoing Platform  version 3.5.1 under development (2022-10-02)
servoAfma6AprilTagPBVS.cpp

Example of eye-in-hand image-based control law. We control here the Afma6 robot at Inria. The velocity is computed in the camera frame. Visual features correspond to the 3D pose of the target (an AprilTag) in the camera frame.

The device used to acquire images is a Realsense D435 device.

Camera intrinsic parameters are retrieved from the Realsense SDK.

The target is an AprilTag that is by default 12cm large. To print your own tag, see https://visp-doc.inria.fr/doxygen/visp-daily/tutorial-detection-apriltag.html You can specify the size of your tag using –tag_size command line option.

/****************************************************************************
*
* ViSP, open source Visual Servoing Platform software.
* Copyright (C) 2005 - 2022 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:
* Data acquisition with RealSense RGB-D sensor and Franka robot.
*
*****************************************************************************/
#include <iostream>
#include <visp3/core/vpCameraParameters.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/vpRobotAfma6.h>
#include <visp3/sensor/vpRealSense2.h>
#include <visp3/visual_features/vpFeatureThetaU.h>
#include <visp3/visual_features/vpFeatureTranslation.h>
#include <visp3/vs/vpServo.h>
#include <visp3/vs/vpServoDisplay.h>
#if defined(VISP_HAVE_REALSENSE2) && (VISP_CXX_STANDARD >= VISP_CXX_STANDARD_11) && \
(defined(VISP_HAVE_X11) || defined(VISP_HAVE_GDI)) && defined(VISP_HAVE_AFMA6)
void display_point_trajectory(const vpImage<unsigned char> &I, const std::vector<vpImagePoint> &vip,
std::vector<vpImagePoint> *traj_vip)
{
for (size_t i = 0; i < vip.size(); i++) {
if (traj_vip[i].size()) {
// Add the point only if distance with the previous > 1 pixel
if (vpImagePoint::distance(vip[i], traj_vip[i].back()) > 1.) {
traj_vip[i].push_back(vip[i]);
}
} else {
traj_vip[i].push_back(vip[i]);
}
}
for (size_t i = 0; i < vip.size(); i++) {
for (size_t j = 1; j < traj_vip[i].size(); j++) {
vpDisplay::displayLine(I, traj_vip[i][j - 1], traj_vip[i][j], vpColor::green, 2);
}
}
}
int main(int argc, char **argv)
{
double opt_tagSize = 0.120;
bool display_tag = true;
int opt_quad_decimate = 2;
bool opt_verbose = false;
bool opt_plot = false;
bool opt_adaptive_gain = false;
bool opt_task_sequencing = false;
double convergence_threshold_t = 0.0005; // Value in [m]
double convergence_threshold_tu = 0.5; // Value in [deg]
for (int i = 1; i < argc; i++) {
if (std::string(argv[i]) == "--tag_size" && i + 1 < argc) {
opt_tagSize = std::stod(argv[i + 1]);
} else if (std::string(argv[i]) == "--verbose") {
opt_verbose = true;
} else if (std::string(argv[i]) == "--plot") {
opt_plot = true;
} else if (std::string(argv[i]) == "--adaptive_gain") {
opt_adaptive_gain = true;
} 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]);
} else if (std::string(argv[i]) == "--no-convergence-threshold") {
convergence_threshold_t = 0.;
convergence_threshold_tu = 0.;
} else if (std::string(argv[i]) == "--help" || std::string(argv[i]) == "-h") {
std::cout
<< argv[0] << " [--tag_size <marker size in meter; default " << opt_tagSize << ">] "
<< "[--quad_decimate <decimation; default " << opt_quad_decimate
<< ">] [--adaptive_gain] [--plot] [--task_sequencing] [--no-convergence-threshold] [--verbose] [--help] [-h]"
<< "\n";
return EXIT_SUCCESS;
}
}
vpRobotAfma6 robot;
try {
std::cout << "WARNING: This example will move the robot! "
<< "Please make sure to have the user stop button at hand!" << std::endl
<< "Press Enter to continue..." << std::endl;
std::cin.ignore();
/*
* Move to a safe position
*/
vpColVector q(6, 0);
q[0] = 0.;
q[1] = 0.;
q[2] = 0.;
q[3] = vpMath::rad(0.);
q[4] = vpMath::rad(0.);
q[5] = vpMath::rad(0.);
std::cout << "Move to joint position: " << q.t() << std::endl;
robot.setPosition(vpRobot::JOINT_STATE, q);
rs2::config config;
unsigned int width = 640, height = 480;
config.enable_stream(RS2_STREAM_COLOR, 640, 480, RS2_FORMAT_RGBA8, 30);
config.enable_stream(RS2_STREAM_DEPTH, 640, 480, RS2_FORMAT_Z16, 30);
config.enable_stream(RS2_STREAM_INFRARED, 640, 480, RS2_FORMAT_Y8, 30);
rs.open(config);
// Get camera intrinsics
std::cout << "cam:\n" << cam << "\n";
vpImage<unsigned char> I(height, width);
#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::vpPoseEstimationMethod poseEstimationMethod = vpDetectorAprilTag::BEST_RESIDUAL_VIRTUAL_VS;
vpDetectorAprilTag detector(tagFamily);
detector.setAprilTagPoseEstimationMethod(poseEstimationMethod);
detector.setDisplayTag(display_tag);
detector.setAprilTagQuadDecimate(opt_quad_decimate);
// Servo
vpHomogeneousMatrix cdMc, cMo, oMo;
// Desired pose to reach
vpHomogeneousMatrix cdMo(vpTranslationVector(0, 0, opt_tagSize * 3), // 3 times tag with along camera z axis
vpRotationMatrix({1, 0, 0, 0, -1, 0, 0, 0, -1}));
cdMc = cdMo * cMo.inverse();
t.buildFrom(cdMc);
tu.buildFrom(cdMc);
vpServo task;
task.addFeature(t, td);
task.addFeature(tu, tud);
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(0.5);
}
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, "Camera velocities");
plotter->initGraph(0, 6);
plotter->initGraph(1, 6);
plotter->setLegend(0, 0, "error_feat_tx");
plotter->setLegend(0, 1, "error_feat_ty");
plotter->setLegend(0, 2, "error_feat_tz");
plotter->setLegend(0, 3, "error_feat_theta_ux");
plotter->setLegend(0, 4, "error_feat_theta_uy");
plotter->setLegend(0, 5, "error_feat_theta_uz");
plotter->setLegend(1, 0, "vc_x");
plotter->setLegend(1, 1, "vc_y");
plotter->setLegend(1, 2, "vc_z");
plotter->setLegend(1, 3, "wc_x");
plotter->setLegend(1, 4, "wc_y");
plotter->setLegend(1, 5, "wc_z");
}
bool final_quit = false;
bool has_converged = false;
bool send_velocities = false;
bool servo_started = false;
std::vector<vpImagePoint> *traj_vip = nullptr; // To memorize point trajectory
static double t_init_servo = vpTime::measureTimeMs();
while (!has_converged && !final_quit) {
double t_start = vpTime::measureTimeMs();
rs.acquire(I);
std::vector<vpHomogeneousMatrix> cMo_vec;
detector.detect(I, opt_tagSize, 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 v_c(6);
// Only one tag is detected
if (cMo_vec.size() == 1) {
cMo = cMo_vec[0];
static bool first_time = true;
if (first_time) {
// Introduce security wrt tag positionning in order to avoid PI rotation
std::vector<vpHomogeneousMatrix> v_oMo(2), v_cdMc(2);
v_oMo[1].buildFrom(0, 0, 0, 0, 0, M_PI);
for (size_t i = 0; i < 2; i++) {
v_cdMc[i] = cdMo * v_oMo[i] * cMo.inverse();
}
if (std::fabs(v_cdMc[0].getThetaUVector().getTheta()) < std::fabs(v_cdMc[1].getThetaUVector().getTheta())) {
oMo = v_oMo[0];
} else {
std::cout << "Desired frame modified to avoid PI rotation of the camera" << std::endl;
oMo = v_oMo[1]; // Introduce PI rotation
}
}
// Update visual features
cdMc = cdMo * oMo * cMo.inverse();
t.buildFrom(cdMc);
tu.buildFrom(cdMc);
if (opt_task_sequencing) {
if (!servo_started) {
if (send_velocities) {
servo_started = true;
}
t_init_servo = vpTime::measureTimeMs();
}
v_c = task.computeControlLaw((vpTime::measureTimeMs() - t_init_servo) / 1000.);
} else {
v_c = task.computeControlLaw();
}
// Display desired and current pose features
vpDisplay::displayFrame(I, cdMo * oMo, cam, opt_tagSize / 1.5, vpColor::yellow, 2);
vpDisplay::displayFrame(I, cMo, cam, opt_tagSize / 2, vpColor::none, 3);
// Get tag corners
std::vector<vpImagePoint> vip = detector.getPolygon(0);
// Get the tag cog corresponding to the projection of the tag frame in the image
vip.push_back(detector.getCog(0));
// Display the trajectory of the points
if (first_time) {
traj_vip = new std::vector<vpImagePoint>[vip.size()];
}
display_point_trajectory(I, vip, traj_vip);
if (opt_plot) {
plotter->plot(0, iter_plot, task.getError());
plotter->plot(1, iter_plot, v_c);
iter_plot++;
}
if (opt_verbose) {
std::cout << "v_c: " << v_c.t() << std::endl;
}
vpThetaUVector cd_tu_c = cdMc.getThetaUVector();
double error_tr = sqrt(cd_t_c.sumSquare());
double error_tu = vpMath::deg(sqrt(cd_tu_c.sumSquare()));
ss.str("");
ss << "error_t: " << error_tr;
vpDisplay::displayText(I, 20, static_cast<int>(I.getWidth()) - 150, ss.str(), vpColor::red);
ss.str("");
ss << "error_tu: " << error_tu;
vpDisplay::displayText(I, 40, static_cast<int>(I.getWidth()) - 150, ss.str(), vpColor::red);
if (opt_verbose)
std::cout << "error translation: " << error_tr << " ; error rotation: " << error_tu << std::endl;
if (error_tr < convergence_threshold_t && error_tu < convergence_threshold_tu) {
has_converged = true;
std::cout << "Servo task has converged" << std::endl;
;
vpDisplay::displayText(I, 100, 20, "Servo task has converged", vpColor::red);
}
if (first_time) {
first_time = false;
}
} // end if (cMo_vec.size() == 1)
else {
v_c = 0;
}
if (!send_velocities) {
v_c = 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;
v_c = 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) {
rs.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;
}
}
}
if (traj_vip) {
delete[] traj_vip;
}
} catch (const vpException &e) {
std::cout << "ViSP exception: " << e.what() << std::endl;
std::cout << "Stop the robot " << std::endl;
return EXIT_FAILURE;
} catch (const std::exception &e) {
std::cout << "ur_rtde exception: " << e.what() << std::endl;
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
#else
int main()
{
#if !defined(VISP_HAVE_REALSENSE2)
std::cout << "Install librealsense-2.x" << std::endl;
#endif
#if (VISP_CXX_STANDARD < VISP_CXX_STANDARD_11)
std::cout << "Build ViSP with c++11 or higher compiler flag (cmake -DUSE_CXX_STANDARD=11)." << std::endl;
#endif
#if !defined(VISP_HAVE_AFMA6)
std::cout << "ViSP is not build with Afma-6 robot support..." << std::endl;
#endif
return EXIT_SUCCESS;
}
#endif
Adaptive gain computation.
Generic class defining intrinsic camera parameters.
Implementation of column vector and the associated operations.
Definition: vpColVector.h:131
static const vpColor red
Definition: vpColor.h:217
static const vpColor none
Definition: vpColor.h:229
static const vpColor yellow
Definition: vpColor.h:225
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 displayFrame(const vpImage< unsigned char > &I, const vpHomogeneousMatrix &cMo, const vpCameraParameters &cam, double size, const vpColor &color=vpColor::none, unsigned int thickness=1, const vpImagePoint &offset=vpImagePoint(0, 0))
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 * what() const
Definition: vpException.cpp:99
Class that defines a 3D visual feature from a axis/angle parametrization that represent the rotatio...
Class that defines the translation visual feature .
Implementation of an homogeneous matrix and operations on such kind of matrices.
vpThetaUVector getThetaUVector() const
vpHomogeneousMatrix inverse() const
vpTranslationVector getTranslationVector() const
void buildFrom(const vpTranslationVector &t, const vpRotationMatrix &R)
static double distance(const vpImagePoint &iP1, const vpImagePoint &iP2)
unsigned int getWidth() const
Definition: vpImage.h:246
static double rad(double deg)
Definition: vpMath.h:117
static double deg(double rad)
Definition: vpMath.h:110
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
void acquire(vpImage< unsigned char > &grey, double *ts=NULL)
vpCameraParameters getCameraParameters(const rs2_stream &stream, vpCameraParameters::vpCameraParametersProjType type=vpCameraParameters::perspectiveProjWithDistortion, int index=-1) const
bool open(const rs2::config &cfg=rs2::config())
Control of Irisa's gantry robot named Afma6.
Definition: vpRobotAfma6.h:212
void setVelocity(const vpRobot::vpControlFrameType frame, const vpColVector &vel)
@ JOINT_STATE
Definition: vpRobot.h:81
@ CAMERA_FRAME
Definition: vpRobot.h:83
@ STATE_POSITION_CONTROL
Initialize the position controller.
Definition: vpRobot.h:68
@ 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.
double sumSquare() const
void setInteractionMatrixType(const vpServoIteractionMatrixType &interactionMatrixType, const vpServoInversionType &interactionMatrixInversion=PSEUDO_INVERSE)
Definition: vpServo.cpp:564
@ EYEINHAND_CAMERA
Definition: vpServo.h:155
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
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
Implementation of a rotation vector as axis-angle minimal representation.
Class that consider the case of a translation vector.
VISP_EXPORT double measureTimeMs()