Visual Servoing Platform  version 3.2.0 under development (2018-08-18)
manServoMomentsSimple.cpp

Minimalist example of moment-based visual servoing with polygon and a simple robot

/****************************************************************************
*
* This file is part of the ViSP software.
* Copyright (C) 2005 - 2017 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
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* 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:
* Example of visual servoing with moments using a polygon as object container
*
* Authors:
* Filip Novotny
*
*****************************************************************************/
#include <visp3/core/vpPoint.h> //the basic tracker
#include <iostream> //some console output
#include <limits>
#include <vector> //store the polygon
#include <visp3/core/vpException.h>
#include <visp3/core/vpMomentCommon.h> //update the common database with the object
#include <visp3/core/vpMomentObject.h> //transmit the polygon to the object
#include <visp3/core/vpPlane.h>
#include <visp3/robot/vpSimulatorCamera.h>
#include <visp3/visual_features/vpFeatureMomentCommon.h> //init the feature database using the information about moment dependencies
#include <visp3/vs/vpServo.h> //visual servoing task
// this function converts the plane defined by the cMo to 1/Z=Ax+By+C plane
// form
void cMoToABC(vpHomogeneousMatrix &cMo, double &A, double &B, double &C);
void cMoToABC(vpHomogeneousMatrix &cMo, double &A, double &B, double &C)
{
vpPlane pl;
pl.setABCD(0, 0, 1.0, 0);
pl.changeFrame(cMo);
if (fabs(pl.getD()) < std::numeric_limits<double>::epsilon()) {
std::cout << "Invalid position:" << std::endl;
std::cout << cMo << std::endl;
std::cout << "Cannot put plane in the form 1/Z=Ax+By+C." << std::endl;
throw vpException(vpException::divideByZeroError, "invalid position!");
}
A = -pl.getA() / pl.getD();
B = -pl.getB() / pl.getD();
C = -pl.getC() / pl.getD();
}
int main()
{
try {
double x[8] = {1, 3, 4, -1, -3, -2, -1, 1};
double y[8] = {0, 1, 4, 4, -2, -2, 1, 0};
double A, B, C, Ad, Bd, Cd;
int nbpoints = 8;
std::vector<vpPoint> vec_p,
vec_p_d; // vectors that contain the vertices of the contour polygon
vpHomogeneousMatrix cMo(0.1, 0.0, 1.0, vpMath::rad(0), vpMath::rad(0), vpMath::rad(0));
vpHomogeneousMatrix wMo; // Set to identity
vpHomogeneousMatrix wMc; // Camera position in the world frame
cMoToABC(cMo, A, B, C);
cMoToABC(cdMo, Ad, Bd, Cd);
// Define source and destination polygons
for (int i = 0; i < nbpoints; i++) {
vpPoint p(x[i], y[i], 0.0);
p.track(cMo);
vec_p.push_back(p);
p.track(cdMo);
vec_p_d.push_back(p);
}
vpMomentObject cur(6); // Create a source moment object with 6 as maximum order
cur.setType(vpMomentObject::DENSE_POLYGON); // The object is defined by a
// countour polygon
cur.fromVector(vec_p); // Init the dense object with the source polygon
vpMomentObject dst(6); // Create a destination moment object with 6 as maximum order
dst.setType(vpMomentObject::DENSE_POLYGON); // The object is defined by a
// countour polygon
dst.fromVector(vec_p_d); // Init the dense object with the destination polygon
// init classic moment primitives (for source)
vpMomentCommon::getAlpha(dst)); // Init classic features
vpFeatureMomentCommon fmdb_cur(mdb_cur);
vpMomentCommon::getAlpha(dst)); // Init classic features
vpFeatureMomentCommon fmdb_dst(mdb_dst);
// update+compute moment primitives from object (for destination)
mdb_dst.updateAll(dst);
// update+compute features (+interaction matrixes) from plane
fmdb_dst.updateAll(Ad, Bd, Cd);
// define visual servoing task
vpServo task;
task.setLambda(1);
task.addFeature(fmdb_cur.getFeatureGravityNormalized(), fmdb_dst.getFeatureGravityNormalized());
task.addFeature(fmdb_cur.getFeatureAn(), fmdb_dst.getFeatureAn());
// the object is NOT symmetric
// select C4 and C6
task.addFeature(fmdb_cur.getFeatureCInvariant(), fmdb_dst.getFeatureCInvariant(),
task.addFeature(fmdb_cur.getFeatureAlpha(), fmdb_dst.getFeatureAlpha());
vpBasicFeature *al = new vpFeatureMomentAlpha(mdb_dst, 0, 0, 1.);
al->init();
al->error(*al);
// param robot
float sampling_time = 0.010f; // Sampling period in seconds
robot.setSamplingTime(sampling_time);
wMc = wMo * cMo.inverse();
robot.setPosition(wMc);
do {
wMc = robot.getPosition();
cMo = wMc.inverse() * wMo;
vec_p.clear();
for (int i = 0; i < nbpoints; i++) {
vpPoint p(x[i], y[i], 0.0);
p.track(cMo);
vec_p.push_back(p);
}
cMoToABC(cMo, A, B, C);
cur.fromVector(vec_p);
// update+compute moment primitives from object (for source)
mdb_cur.updateAll(cur);
// update+compute features (+interaction matrixes) from plane
fmdb_cur.updateAll(A, B, C);
task.print();
double t = vpTime::measureTimeMs();
vpTime::wait(t, sampling_time * 1000); // Wait 10 ms
} while ((task.getError()).sumSquare() > 0.005);
std::cout << "final error=" << (task.getError()).sumSquare() << std::endl;
return EXIT_SUCCESS;
} catch (const vpException &e) {
std::cout << "Catch an exception: " << e << std::endl;
return EXIT_FAILURE;
}
}