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/* SPDX-FileCopyrightText: 2009 Ruben Smits
*
* SPDX-License-Identifier: LGPL-2.1-or-later */
/** \file
* \ingroup intern_itasc
*/
#include "ConstraintSet.hpp"
#include "kdl/utilities/svd_eigen_HH.hpp"
namespace iTaSC {
ConstraintSet::ConstraintSet(unsigned int _nc,double accuracy,unsigned int maximum_iterations):
m_nc(_nc),
m_Cf(e_zero_matrix(m_nc,6)),
m_Wy(e_scalar_vector(m_nc,1.0)),
m_y(m_nc),m_ydot(e_zero_vector(m_nc)),m_chi(e_zero_vector(6)),
m_S(6),m_temp(6),m_tdelta(6),
m_Jf(e_identity_matrix(6,6)),
m_U(e_identity_matrix(6,6)),m_V(e_identity_matrix(6,6)),m_B(e_zero_matrix(6,6)),
m_Jf_inv(e_zero_matrix(6,6)),
m_internalPose(F_identity), m_externalPose(F_identity),
m_constraintCallback(NULL), m_constraintParam(NULL),
m_toggle(false),m_substep(false),
m_threshold(accuracy),m_maxIter(maximum_iterations)
{
m_maxDeltaChi = e_scalar(0.52);
}
ConstraintSet::ConstraintSet():
m_nc(0),
m_internalPose(F_identity), m_externalPose(F_identity),
m_constraintCallback(NULL), m_constraintParam(NULL),
m_toggle(false),m_substep(false),
m_threshold(0.0),m_maxIter(0)
{
m_maxDeltaChi = e_scalar(0.52);
}
void ConstraintSet::reset(unsigned int _nc,double accuracy,unsigned int maximum_iterations)
{
m_nc = _nc;
m_Jf = e_identity_matrix(6,6);
m_Cf = e_zero_matrix(m_nc,6);
m_U = e_identity_matrix(6,6);
m_V = e_identity_matrix(6,6);
m_B = e_zero_matrix(6,6);
m_Jf_inv = e_zero_matrix(6,6),
m_Wy = e_scalar_vector(m_nc,1.0),
m_chi = e_zero_vector(6);
m_chidot = e_zero_vector(6);
m_y = e_zero_vector(m_nc);
m_ydot = e_zero_vector(m_nc);
m_S = e_zero_vector(6);
m_temp = e_zero_vector(6);
m_tdelta = e_zero_vector(6);
m_threshold = accuracy;
m_maxIter = maximum_iterations;
}
ConstraintSet::~ConstraintSet() {
}
void ConstraintSet::modelUpdate(Frame& _external_pose,const Timestamp& timestamp)
{
m_chi+=m_chidot*timestamp.realTimestep;
m_externalPose = _external_pose;
//update the internal pose and Jf
updateJacobian();
//check if loop is already closed, if not update the pose and Jf
unsigned int iter=0;
while(iter<5&&!closeLoop())
iter++;
}
double ConstraintSet::getMaxTimestep(double& timestep)
{
e_scalar maxChidot = m_chidot.array().abs().maxCoeff();
if (timestep*maxChidot > m_maxDeltaChi) {
timestep = m_maxDeltaChi/maxChidot;
}
return timestep;
}
bool ConstraintSet::initialise(Frame& init_pose){
m_externalPose=init_pose;
// get current Jf
updateJacobian();
unsigned int iter=0;
while(iter<m_maxIter&&!closeLoop()){
iter++;
}
if (iter<m_maxIter)
return true;
else
return false;
}
bool ConstraintSet::setControlParameter(int id, ConstraintAction action, double data, double timestep)
{
ConstraintValues values;
ConstraintSingleValue value;
values.values = &value;
values.number = 0;
values.action = action;
values.id = id;
value.action = action;
value.id = id;
switch (action) {
case ACT_NONE:
return true;
case ACT_VALUE:
value.yd = data;
values.number = 1;
break;
case ACT_VELOCITY:
value.yddot = data;
values.number = 1;
break;
case ACT_TOLERANCE:
values.tolerance = data;
break;
case ACT_FEEDBACK:
values.feedback = data;
break;
case ACT_ALPHA:
values.alpha = data;
break;
default:
assert(action==ACT_NONE);
break;
}
return setControlParameters(&values, 1, timestep);
}
bool ConstraintSet::closeLoop(){
//Invert Jf
//TODO: svd_boost_Macie has problems if Jf contains zero-rows
//toggle=!toggle;
//svd_boost_Macie(Jf,U,S,V,B,temp,1e-3*threshold,toggle);
int ret = KDL::svd_eigen_HH(m_Jf,m_U,m_S,m_V,m_temp);
if(ret<0)
return false;
// the reference point and frame of the jacobian is the base frame
// m_externalPose-m_internalPose is the twist to extend the end effector
// to get the required pose => change the reference point to the base frame
Twist twist_delta(diff(m_internalPose,m_externalPose));
twist_delta=twist_delta.RefPoint(-m_internalPose.p);
for(unsigned int i=0;i<6;i++)
m_tdelta(i)=twist_delta(i);
//TODO: use damping in constraintset inversion?
for(unsigned int i=0;i<6;i++) {
if(m_S(i)<m_threshold){
m_B.row(i).setConstant(0.0);
} else {
m_B.row(i) = m_U.col(i)/m_S(i);
}
}
m_Jf_inv.noalias()=m_V*m_B;
m_chi.noalias()+=m_Jf_inv*m_tdelta;
updateJacobian();
// m_externalPose-m_internalPose in end effector frame
// this is just to compare the pose, a different formula would work too
return Equal(m_internalPose.Inverse()*m_externalPose,F_identity,m_threshold);
}
}
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