Visual Servoing Platform  version 3.0.0
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 - 2015 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
* ("GPL") version 2 as published by the Free Software Foundation.
* 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:
* Example of visual servoing with moments using a polygon as object container
*
* Authors:
* Filip Novotny
*
*****************************************************************************/
#include <visp3/core/vpPoint.h> //the basic tracker
#include <vector> //store the polygon
#include <visp3/core/vpMomentObject.h> //transmit the polygon to the object
#include <visp3/core/vpMomentCommon.h> //update the common database with the object
#include <visp3/visual_features/vpFeatureMomentCommon.h> //init the feature database using the information about moment dependencies
#include <visp3/vs/vpServo.h> //visual servoing task
#include <visp3/robot/vpSimulatorCamera.h>
#include <visp3/core/vpPlane.h>
#include <visp3/core/vpException.h>
#include <limits>
#include <iostream> //some console output
//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 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)
vpFeatureMomentCommon fmdb_cur(mdb_cur);
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 0;
}
catch(vpException e) {
std::cout << "Catch an exception: " << e << std::endl;
return 1;
}
}