bdk-blender/intern/itasc/WSDLSSolver.cpp

140 lines
3.2 KiB
C++

/* SPDX-FileCopyrightText: 2009 Ruben Smits
*
* SPDX-License-Identifier: LGPL-2.1-or-later */
/** \file
* \ingroup intern_itasc
*/
#include "WSDLSSolver.hpp"
#include "kdl/utilities/svd_eigen_HH.hpp"
#include <cstdio>
namespace iTaSC {
WSDLSSolver::WSDLSSolver() :
m_ns(0), m_nc(0), m_nq(0)
{
// default maximum speed: 50 rad/s
m_qmax = 50.0;
}
WSDLSSolver::~WSDLSSolver() {
}
bool WSDLSSolver::init(unsigned int _nq, unsigned int _nc, const std::vector<bool>& gc)
{
if (_nc == 0 || _nq == 0 || gc.size() != _nc)
return false;
m_nc = _nc;
m_nq = _nq;
m_ns = std::min(m_nc,m_nq);
m_AWq = e_zero_matrix(m_nc,m_nq);
m_WyAWq = e_zero_matrix(m_nc,m_nq);
m_WyAWqt = e_zero_matrix(m_nq,m_nc);
m_S = e_zero_vector(std::max(m_nc,m_nq));
m_Wy_ydot = e_zero_vector(m_nc);
m_ytask = gc;
if (m_nq > m_nc) {
m_transpose = true;
m_temp = e_zero_vector(m_nc);
m_U = e_zero_matrix(m_nc,m_nc);
m_V = e_zero_matrix(m_nq,m_nc);
m_WqV = e_zero_matrix(m_nq,m_nc);
} else {
m_transpose = false;
m_temp = e_zero_vector(m_nq);
m_U = e_zero_matrix(m_nc,m_nq);
m_V = e_zero_matrix(m_nq,m_nq);
m_WqV = e_zero_matrix(m_nq,m_nq);
}
return true;
}
bool WSDLSSolver::solve(const e_matrix& A, const e_vector& Wy, const e_vector& ydot, const e_matrix& Wq, e_vector& qdot, e_scalar& nlcoef)
{
unsigned int i, j, l;
e_scalar N, M;
// Create the Weighted jacobian
m_AWq.noalias() = A*Wq;
for (i=0; i<m_nc; i++)
m_WyAWq.row(i) = Wy(i)*m_AWq.row(i);
// Compute the SVD of the weighted jacobian
int ret;
if (m_transpose) {
m_WyAWqt = m_WyAWq.transpose();
ret = KDL::svd_eigen_HH(m_WyAWqt,m_V,m_S,m_U,m_temp);
} else {
ret = KDL::svd_eigen_HH(m_WyAWq,m_U,m_S,m_V,m_temp);
}
if(ret<0)
return false;
m_Wy_ydot = Wy.array() * ydot.array();
m_WqV.noalias() = Wq*m_V;
qdot.setZero();
e_scalar maxDeltaS = e_scalar(0.0);
e_scalar prevS = e_scalar(0.0);
e_scalar maxS = e_scalar(1.0);
for(i=0;i<m_ns;++i) {
e_scalar norm, mag, alpha, _qmax, Sinv, vmax, damp;
e_scalar S = m_S(i);
bool prev;
if (S < KDL::epsilon)
break;
Sinv = e_scalar(1.)/S;
if (i > 0) {
if ((prevS-S) > maxDeltaS) {
maxDeltaS = (prevS-S);
maxS = prevS;
}
}
N = M = e_scalar(0.);
for (l=0, prev=m_ytask[0], norm=e_scalar(0.); l<m_nc; l++) {
if (prev == m_ytask[l]) {
norm += m_U(l,i)*m_U(l,i);
} else {
N += std::sqrt(norm);
norm = m_U(l,i)*m_U(l,i);
}
prev = m_ytask[l];
}
N += std::sqrt(norm);
for (j=0; j<m_nq; j++) {
for (l=0, prev=m_ytask[0], norm=e_scalar(0.), mag=e_scalar(0.); l<m_nc; l++) {
if (prev == m_ytask[l]) {
norm += m_WyAWq(l,j)*m_WyAWq(l,j);
} else {
mag += std::sqrt(norm);
norm = m_WyAWq(l,j)*m_WyAWq(l,j);
}
prev = m_ytask[l];
}
mag += std::sqrt(norm);
M += fabs(m_V(j,i))*mag;
}
M *= Sinv;
alpha = m_U.col(i).dot(m_Wy_ydot);
_qmax = (N < M) ? m_qmax*N/M : m_qmax;
vmax = m_WqV.col(i).array().abs().maxCoeff();
norm = fabs(Sinv*alpha*vmax);
if (norm > _qmax) {
damp = Sinv*alpha*_qmax/norm;
} else {
damp = Sinv*alpha;
}
qdot += m_WqV.col(i)*damp;
prevS = S;
}
if (maxDeltaS == e_scalar(0.0))
nlcoef = e_scalar(KDL::epsilon);
else
nlcoef = (maxS-maxDeltaS)/maxS;
return true;
}
}