bool Equal(const MomentumJacobian& a,const MomentumJacobian& b,double eps)
{
if(a.rows()==b.rows()&&a.columns()==b.columns()){
return a.data.isApprox(b.data,eps);
}else
return false;
}
bool changeRefPoint(const MomentumJacobian& src1, const Vector& base_AB, MomentumJacobian& dest)
{
if(src1.columns()!=dest.columns())
return false;
for(unsigned int i=0;i<src1.columns();i++)
dest.setColumn(i,src1.getColumn(i).RefPoint(base_AB));
return true;
}
bool changeRefFrame(const MomentumJacobian& src1,const Frame& frame, MomentumJacobian& dest)
{
if(src1.columns()!=dest.columns())
return false;
for(unsigned int i=0;i<src1.columns();i++)
dest.setColumn(i,frame*src1.getColumn(i));
return true;
}
bool changeBase(const MomentumJacobian& src1, const Rotation& rot, MomentumJacobian& dest)
{
if(src1.columns()!=dest.columns())
return false;
for(unsigned int i=0;i<src1.columns();i++)
dest.setColumn(i,rot*src1.getColumn(i));;
return true;
}
bool multiplyInertiaJacobian(const Jacobian& src, const RigidBodyInertia& I, MomentumJacobian& dest)
{
if(src.columns()!=dest.columns())
return false;
for(unsigned int i=0;i<src.columns();i++)
dest.setColumn(i,I*src.getColumn(i));;
return true;
}
bool divideJacobianInertia(const MomentumJacobian& src, const RigidBodyInertia& I, Jacobian& dest)
{
/** \todo if the inertia matrix is singular ? */
if(src.columns()!=dest.columns() || I.getMass() == 0)
return false;
for(unsigned int i=0;i<src.columns();i++)
dest.setColumn(i,src.getColumn(i)/I);
return true;
}
int crba_momentum_jacobian_loop(const UndirectedTree & undirected_tree,
const Traversal & traversal,
const JntArray & q,
std::vector<RigidBodyInertia> & Ic,
MomentumJacobian & H,
RigidBodyInertia & InertiaCOM
)
{
#ifndef NDEBUG
if( undirected_tree.getNrOfLinks() != traversal.getNrOfVisitedLinks() ||
undirected_tree.getNrOfDOFs() != q.rows() ||
Ic.size() != undirected_tree.getNrOfLinks() ||
H.columns() != (undirected_tree.getNrOfDOFs() + 6) )
{
std::cerr << "crba_momentum_jacobian_loop: input data error" << std::endl;
return -1;
}
#endif
double q_;
Wrench F = Wrench::Zero();
//Sweep from root to leaf
for(int i=0; i<(int)traversal.getNrOfVisitedLinks(); i++)
{
LinkMap::const_iterator link_it = traversal.getOrderedLink(i);
int link_index = link_it->getLinkIndex();
//Collect RigidBodyInertia
Ic[link_index]=link_it->getInertia();
}
for(int i=(int)traversal.getNrOfVisitedLinks()-1; i >= 1; i-- ) {
int dof_id;
LinkMap::const_iterator link_it = traversal.getOrderedLink(i);
int link_index = link_it->getLinkIndex();
LinkMap::const_iterator parent_it = traversal.getParentLink(link_index);
int parent_index = parent_it->getLinkIndex();
if( link_it->getAdjacentJoint(parent_it)->getNrOfDOFs() == 1 ) {
dof_id = link_it->getAdjacentJoint(parent_it)->getDOFIndex();
q_ = q(dof_id);
} else {
q_ = 0.0;
dof_id = -1;
}
Ic[parent_index] = Ic[parent_index]+link_it->pose(parent_it,q_)*Ic[link_index];
if( link_it->getAdjacentJoint(parent_it)->getNrOfDOFs() == 1 ) {
KDL::Twist S_link_parent = parent_it->S(link_it,q_);
F = Ic[link_index]*S_link_parent;
if( traversal.getParentLink(link_it) != undirected_tree.getInvalidLinkIterator() ) {
double q__;
int dof_id_;
LinkMap::const_iterator predecessor_it = traversal.getParentLink(link_it);
LinkMap::const_iterator successor_it = link_it;
while(true) {
if( predecessor_it->getAdjacentJoint(successor_it)->getNrOfDOFs() == 1 ) {
q__ = q( predecessor_it->getAdjacentJoint(successor_it)->getDOFIndex());
} else {
q__ = 0.0;
}
F = successor_it->pose(predecessor_it,q__)*F;
successor_it = predecessor_it;
predecessor_it = traversal.getParentLink(predecessor_it);
if( predecessor_it == undirected_tree.getInvalidLinkIterator() ) {
break;
}
if( predecessor_it->getAdjacentJoint(successor_it)->getNrOfDOFs() == 1 ) {
dof_id_ = predecessor_it->getAdjacentJoint(successor_it)->getDOFIndex();
q__ = q(dof_id_);
} else {
q__ = 0.0;
dof_id_ = -1;
}
}
if( dof_id >= 0 ) {
H.data.block(0,6+dof_id,6,1) = toEigen(F);
}
//The first 6x6 submatrix of the Momentum Jacobian are simply the spatial inertia
//of all the structure expressed in the base reference frame
H.data.block(0,0,6,6) = toEigen(Ic[traversal.getBaseLink()->getLinkIndex()]);
}
}
}
//We have then to translate the reference point of the obtained jacobian to the com
//The Ic[traversal.order[0]->getLink(index)] contain the spatial inertial of all the tree
//expressed in link coordite frames
Vector com = Ic[traversal.getBaseLink()->getLinkIndex()].getCOG();
H.changeRefPoint(com);
InertiaCOM = Frame(com)*Ic[traversal.getBaseLink()->getLinkIndex()];
return 0;
}