Visual Servoing Platform  version 3.2.0 under development (2018-12-11)
mbot-apriltag-ibvs.cpp
#include <visp3/core/vpSerial.h>
#include <visp3/core/vpXmlParserCamera.h>
#include <visp3/core/vpMomentObject.h>
#include <visp3/core/vpPoint.h>
#include <visp3/core/vpMomentBasic.h>
#include <visp3/core/vpMomentGravityCenter.h>
#include <visp3/core/vpMomentDatabase.h>
#include <visp3/core/vpMomentCentered.h>
#include <visp3/core/vpMomentAreaNormalized.h>
#include <visp3/core/vpMomentGravityCenterNormalized.h>
#include <visp3/core/vpPixelMeterConversion.h>
#include <visp3/detection/vpDetectorAprilTag.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/sensor/vpV4l2Grabber.h>
#include <visp3/io/vpImageIo.h>
#include <visp3/visual_features/vpFeatureMomentAreaNormalized.h>
#include <visp3/visual_features/vpFeatureMomentGravityCenterNormalized.h>
#include <visp3/vs/vpServo.h>
#include <visp3/robot/vpUnicycle.h>
int main(int argc, const char **argv)
{
#if defined(VISP_HAVE_APRILTAG) && defined(VISP_HAVE_V4L2)
int device = 0;
double tagSize = 0.065;
float quad_decimate = 4.0;
int nThreads = 2;
std::string intrinsic_file = "";
std::string camera_name = "";
bool display_tag = false;
bool display_on = false;
bool serial_off = false;
bool save_image = false; // Only possible if display_on = true
for (int i = 1; i < argc; i++) {
if (std::string(argv[i]) == "--tag_size" && i + 1 < argc) {
tagSize = std::atof(argv[i + 1]);
} else if (std::string(argv[i]) == "--input" && i + 1 < argc) {
device = std::atoi(argv[i + 1]);
} else if (std::string(argv[i]) == "--quad_decimate" && i + 1 < argc) {
quad_decimate = (float)atof(argv[i + 1]);
} else if (std::string(argv[i]) == "--nthreads" && i + 1 < argc) {
nThreads = std::atoi(argv[i + 1]);
} else if (std::string(argv[i]) == "--intrinsic" && i + 1 < argc) {
intrinsic_file = std::string(argv[i + 1]);
} else if (std::string(argv[i]) == "--camera_name" && i + 1 < argc) {
camera_name = std::string(argv[i + 1]);
} else if (std::string(argv[i]) == "--display_tag") {
display_tag = true;
#if defined(VISP_HAVE_X11)
} else if (std::string(argv[i]) == "--display_on") {
display_on = true;
} else if (std::string(argv[i]) == "--save_image") {
save_image = true;
#endif
} else if (std::string(argv[i]) == "--serial_off") {
serial_off = true;
} else if (std::string(argv[i]) == "--tag_family" && i + 1 < argc) {
tagFamily = (vpDetectorAprilTag::vpAprilTagFamily)std::atoi(argv[i + 1]);
} else if (std::string(argv[i]) == "--help" || std::string(argv[i]) == "-h") {
std::cout << "Usage: " << argv[0]
<< " [--input <camera input>] [--tag_size <tag_size in m>]"
" [--quad_decimate <quad_decimate>] [--nthreads <nb>]"
" [--intrinsic <intrinsic file>] [--camera_name <camera name>]"
" [--tag_family <family> (0: TAG_36h11, 1: TAG_36h10, 2: "
"TAG_36ARTOOLKIT,"
" 3: TAG_25h9, 4: TAG_25h7, 5: TAG_16h5)]"
" [--display_tag]";
#if defined(VISP_HAVE_X11)
std::cout << " [--display_on] [--save_image]";
#endif
std::cout << " [--serial_off] [--help]" << std::endl;
return EXIT_SUCCESS;
}
}
// Me Auriga led ring
// if serial com ok: led 1 green
// if exception: led 1 red
// if tag detected: led 2 green, else led 2 red
// if motor left: led 3 blue
// if motor right: led 4 blue
vpSerial *serial = NULL;
if (! serial_off) {
serial = new vpSerial("/dev/ttyAMA0", 115200);
serial->write("LED_RING=0,0,0,0\n"); // Switch off all led
serial->write("LED_RING=1,0,10,0\n"); // Switch on led 1 to green: serial ok
}
try {
std::ostringstream device_name;
device_name << "/dev/video" << device;
g.setDevice(device_name.str());
g.setScale(1);
g.acquire(I);
vpDisplay *d = NULL;
#ifdef VISP_HAVE_X11
if (display_on) {
d = new vpDisplayX(I);
}
#endif
cam.initPersProjWithoutDistortion(615.1674805, 615.1675415, I.getWidth() / 2., I.getHeight() / 2.);
#ifdef VISP_HAVE_XML2
if (!intrinsic_file.empty() && !camera_name.empty())
parser.parse(cam, intrinsic_file, camera_name, vpCameraParameters::perspectiveProjWithoutDistortion);
#endif
std::cout << "cam:\n" << cam << std::endl;
std::cout << "tagFamily: " << tagFamily << std::endl;
std::cout << "tagSize: " << tagSize << std::endl;
vpDetectorAprilTag detector(tagFamily);
detector.setAprilTagQuadDecimate(quad_decimate);
detector.setAprilTagNbThreads(nThreads);
detector.setDisplayTag(display_tag);
vpServo task;
if (display_on)
lambda.initStandard(2.5, 0.4, 30); // lambda(0)=2.5, lambda(oo)=0.4 and lambda'(0)=30
else
lambda.initStandard(4, 0.4, 30); // lambda(0)=4, lambda(oo)=0.4 and lambda'(0)=30
vpUnicycle robot;
task.setLambda(lambda);
cRe[0][0] = 0; cRe[0][1] = -1; cRe[0][2] = 0;
cRe[1][0] = 0; cRe[1][1] = 0; cRe[1][2] = -1;
cRe[2][0] = 1; cRe[2][1] = 0; cRe[2][2] = 0;
task.set_cVe(cVe);
vpMatrix eJe(6, 2, 0);
eJe[0][0] = eJe[5][1] = 1.0;
std::cout << "eJe: \n" << eJe << std::endl;
// Desired distance to the target
double Z_d = 0.4;
// Define the desired polygon corresponding the the AprilTag CLOCKWISE
double X[4] = {tagSize/2., tagSize/2., -tagSize/2., -tagSize/2.};
double Y[4] = {tagSize/2., -tagSize/2., -tagSize/2., tagSize/2.};
std::vector<vpPoint> vec_P, vec_P_d;
for (int i = 0; i < 4; i++) {
vpPoint P_d(X[i], Y[i], 0);
vpHomogeneousMatrix cdMo(0, 0, Z_d, 0, 0, 0);
P_d.track(cdMo); //
vec_P_d.push_back(P_d);
}
vpMomentObject m_obj(3), m_obj_d(3);
vpMomentDatabase mdb, mdb_d;
vpMomentBasic mb_d; // Here only to get the desired area m00
vpMomentCentered mc, mc_d;
vpMomentAreaNormalized man(0, Z_d), man_d(0, Z_d); // Declare normalized area. Desired area parameter will be updated below with m00
vpMomentGravityCenterNormalized mgn, mgn_d; // Declare normalized gravity center
// Desired moments
m_obj_d.setType(vpMomentObject::DENSE_POLYGON); // Consider the AprilTag as a polygon
m_obj_d.fromVector(vec_P_d); // Initialize the object with the points coordinates
mb_d.linkTo(mdb_d); // Add basic moments to database
mg_d.linkTo(mdb_d); // Add gravity center to database
mc_d.linkTo(mdb_d); // Add centered moments to database
man_d.linkTo(mdb_d); // Add area normalized to database
mgn_d.linkTo(mdb_d); // Add gravity center normalized to database
mdb_d.updateAll(m_obj_d); // All of the moments must be updated, not just an_d
mg_d.compute(); // Compute gravity center moment
mc_d.compute(); // Compute centered moments AFTER gravity center
double area = 0;
area = mb_d.get(2, 0) + mb_d.get(0, 2);
else
area = mb_d.get(0, 0);
// Update an moment with the desired area
man_d.setDesiredArea(area);
man_d.compute(); // Compute area normalized moment AFTER centered moments
mgn_d.compute(); // Compute gravity center normalized moment AFTER area normalized moment
// Desired plane
double A = 0.0;
double B = 0.0;
double C = 1.0 / Z_d;
// Construct area normalized features
vpFeatureMomentGravityCenterNormalized s_mgn(mdb, A, B, C), s_mgn_d(mdb_d, A, B, C);
vpFeatureMomentAreaNormalized s_man(mdb, A, B, C), s_man_d(mdb_d, A, B, C);
// Add the features
task.addFeature(s_man, s_man_d);
// Update desired gravity center normalized feature
s_mgn_d.update(A, B, C);
// Update desired area normalized feature
s_man_d.update(A, B, C);
std::vector<double> time_vec;
for (;;) {
g.acquire(I);
double t = vpTime::measureTimeMs();
std::vector<vpHomogeneousMatrix> cMo_vec;
detector.detect(I, tagSize, cam, cMo_vec);
time_vec.push_back(t);
std::stringstream ss;
ss << "Detection time: " << t << " ms";
vpDisplay::displayText(I, 40, 20, ss.str(), vpColor::red);
if (detector.getNbObjects() == 1) {
if (! serial_off) {
serial->write("LED_RING=2,0,10,0\n"); // Switch on led 2 to green: tag detected
}
// Update current points used to compute the moments
std::vector< vpImagePoint > vec_ip = detector.getPolygon(0);
vec_P.clear();
for (size_t i = 0; i < vec_ip.size(); i++) { // size = 4
double x = 0, y = 0;
vpPixelMeterConversion::convertPoint(cam, vec_ip[i], x, y);
P.set_x(x);
P.set_y(y);
vec_P.push_back(P);
}
// Display visual features
vpDisplay::displayPolygon(I, vec_ip, vpColor::green, 3); // Current polygon used to compure an moment
vpDisplay::displayCross(I, detector.getCog(0), 15, vpColor::green, 3); // Current polygon used to compure an moment
vpDisplay::displayLine(I, 0, cam.get_u0(), I.getHeight()-1, cam.get_u0(), vpColor::red, 3); // Vertical line as desired x position
// Current moments
m_obj.setType(vpMomentObject::DENSE_POLYGON); // Consider the AprilTag as a polygon
m_obj.fromVector(vec_P); // Initialize the object with the points coordinates
mg.linkTo(mdb); // Add gravity center to database
mc.linkTo(mdb); // Add centered moments to database
man.linkTo(mdb); // Add area normalized to database
mgn.linkTo(mdb); // Add gravity center normalized to database
mdb.updateAll(m_obj); // All of the moments must be updated, not just an_d
mg.compute(); // Compute gravity center moment
mc.compute(); // Compute centered moments AFTER gravity center
man.setDesiredArea(area); // Since desired area was init at 0, because unknow at contruction, need to be updated here
man.compute(); // Compute area normalized moment AFTER centered moment
mgn.compute(); // Compute gravity center normalized moment AFTER area normalized moment
s_mgn.update(A, B, C);
s_mgn.compute_interaction();
s_man.update(A, B, C);
s_man.compute_interaction();
task.set_cVe(cVe);
task.set_eJe(eJe);
// Compute the control law. Velocities are computed in the mobile robot reference frame
std::cout << "Send velocity to the mbot: " << v[0] << " m/s " << vpMath::deg(v[1]) << " deg/s" << std::endl;
task.print();
double radius = 0.0325;
double L = 0.0725;
double motor_left = (-v[0] - L * v[1]) / radius;
double motor_right = ( v[0] - L * v[1]) / radius;
std::cout << "motor left vel: " << motor_left << " motor right vel: " << motor_right << std::endl;
if (! serial_off) {
// serial->write("LED_RING=3,0,0,10\n"); // Switch on led 3 to blue: motor left servoed
// serial->write("LED_RING=4,0,0,10\n"); // Switch on led 4 to blue: motor right servoed
}
std::stringstream ss;
double rpm_left = motor_left * 30. / M_PI;
double rpm_right = motor_right * 30. / M_PI;
ss << "MOTOR_RPM=" << vpMath::round(rpm_left) << "," << vpMath::round(rpm_right) << "\n";
std::cout << "Send: " << ss.str() << std::endl;
if (! serial_off) {
serial->write(ss.str());
}
}
else {
// stop the robot
if (! serial_off) {
serial->write("LED_RING=2,10,0,0\n"); // Switch on led 2 to red: tag not detected
// serial->write("LED_RING=3,0,0,0\n"); // Switch on led 3 to blue: motor left not servoed
// serial->write("LED_RING=4,0,0,0\n"); // Switch on led 4 to blue: motor right not servoed
serial->write("MOTOR_RPM=0,-0\n"); // Stop the robot
}
}
vpDisplay::displayText(I, 20, 20, "Click to quit.", vpColor::red);
if (display_on && save_image) {
vpImageIo::write(O, "image.png");
}
if (vpDisplay::getClick(I, false))
break;
}
if (! serial_off) {
serial->write("LED_RING=0,0,0,0\n"); // Switch off all led
}
std::cout << "Benchmark computation time" << std::endl;
std::cout << "Mean / Median / Std: " << vpMath::getMean(time_vec) << " ms"
<< " ; " << vpMath::getMedian(time_vec) << " ms"
<< " ; " << vpMath::getStdev(time_vec) << " ms" << std::endl;
if (display_on)
delete d;
if (! serial_off) {
delete serial;
}
} catch (const vpException &e) {
std::cerr << "Catch an exception: " << e.getMessage() << std::endl;
if (! serial_off) {
serial->write("LED_RING=1,10,0,0\n"); // Switch on led 1 to red
}
}
return EXIT_SUCCESS;
#else
(void)argc;
(void)argv;
#ifndef VISP_HAVE_APRILTAG
std::cout << "ViSP is not build with Apriltag support" << std::endl;
#endif
#ifndef VISP_HAVE_V4L2
std::cout << "ViSP is not build with v4l2 support" << std::endl;
#endif
std::cout << "Install missing 3rd parties, configure and build ViSP to run this tutorial" << std::endl;
return EXIT_SUCCESS;
#endif
}