Recursive newton euler inverse dynamics solver for kinematic trees. More...

#include <treeidsolver_recursive_newton_euler.hpp>

Inheritance diagram for KDL::TreeIdSolver_RNE:

Public Member Functions
int	CartToJnt (const JntArray &q, const JntArray &q_dot, const JntArray &q_dotdot, const WrenchMap &f_ext, JntArray &torques)
	TreeIdSolver_RNE (const Tree &tree, Vector grav)
virtual void	updateInternalDataStructures ()
Private Member Functions
void	initAuxVariables ()
	Helper function to initialize private members X, S, v, a, f.
void	rne_step (SegmentMap::const_iterator segment, const JntArray &q, const JntArray &q_dot, const JntArray &q_dotdot, const WrenchMap &f_ext, JntArray &torques)
	One recursion step.
Private Attributes
std::map< std::string, Twist >	a
Twist	ag
std::map< std::string, Wrench >	f
unsigned int	nj
unsigned int	ns
std::map< std::string, Twist >	S
const Tree &	tree
std::map< std::string, Twist >	v
std::map< std::string, Frame >	X

Detailed Description

Recursive newton euler inverse dynamics solver for kinematic trees.

It calculates the torques for the joints, given the motion of the joints (q,qdot,qdotdot), external forces on the segments (expressed in the segments reference frame) and the dynamical parameters of the segments.

This is an extension of the inverse dynamic solver for kinematic chains,

See also:: ChainIdSolver_RNE. The main difference is the use of STL maps instead of vectors to represent external wrenches (as well as internal variables exploited during the recursion).

Definition at line 41 of file treeidsolver_recursive_newton_euler.hpp.

Constructor & Destructor Documentation

KDL::TreeIdSolver_RNE::TreeIdSolver_RNE	(	const Tree &	tree,
		Vector	grav
	)

Constructor for the solver, it will allocate all the necessary memory

Parameters:

tree	The kinematic tree to calculate the inverse dynamics for, an internal reference will be stored.
grav	The gravity vector to use during the calculation.

Definition at line 28 of file treeidsolver_recursive_newton_euler.cpp.

Member Function Documentation

int KDL::TreeIdSolver_RNE::CartToJnt	(	const JntArray &	q,
		const JntArray &	q_dot,
		const JntArray &	q_dotdot,
		const WrenchMap &	f_ext,
		JntArray &	torques
	)		`[virtual]`

Function to calculate from Cartesian forces to joint torques. Input parameters;

Parameters:

q	The current joint positions
q_dot	The current joint velocities
q_dotdot	The current joint accelerations
f_ext	The external forces (no gravity) on the segments Output parameters:
torques	the resulting torques for the joints

Implements KDL::TreeIdSolver.

Definition at line 52 of file treeidsolver_recursive_newton_euler.cpp.

void KDL::TreeIdSolver_RNE::initAuxVariables ( ) [private]

Helper function to initialize private members X, S, v, a, f.

Definition at line 41 of file treeidsolver_recursive_newton_euler.cpp.

void KDL::TreeIdSolver_RNE::rne_step	(	SegmentMap::const_iterator	segment,
		const JntArray &	q,
		const JntArray &	q_dot,
		const JntArray &	q_dotdot,
		const WrenchMap &	f_ext,
		JntArray &	torques
	)		`[private]`

One recursion step.

Definition at line 78 of file treeidsolver_recursive_newton_euler.cpp.

void KDL::TreeIdSolver_RNE::updateInternalDataStructures ( ) [virtual]

Update the internal data structures. This is required if the number of segments or number of joints of a chain/tree have changed. This provides a single point of contact for solver memory allocations.

Implements KDL::SolverI.

Definition at line 35 of file treeidsolver_recursive_newton_euler.cpp.