#include <chainiksolvervel_pinv_nso.hpp>

Inheritance diagram for KDL::ChainIkSolverVel_pinv_nso:

Public Member Functions
virtual int	CartToJnt (const JntArray &q_in, const Twist &v_in, JntArray &qdot_out)
virtual int	CartToJnt (const JntArray &q_init, const FrameVel &v_in, JntArrayVel &q_out)
	ChainIkSolverVel_pinv_nso (const Chain &chain, const JntArray &opt_pos, const JntArray &weights, double eps=0.00001, int maxiter=150, double alpha=0.25)
	ChainIkSolverVel_pinv_nso (const Chain &chain, double eps=0.00001, int maxiter=150, double alpha=0.25)
const double &	getAlpha () const
const JntArray &	getOptPos () const
int	getSVDResult () const
const JntArray &	getWeights () const
virtual int	setAlpha (const double alpha)
virtual int	setOptPos (const JntArray &opt_pos)
virtual int	setWeights (const JntArray &weights)
virtual void	updateInternalDataStructures ()
	~ChainIkSolverVel_pinv_nso ()
Private Attributes
double	alpha
const Chain &	chain
double	eps
Jacobian	jac
ChainJntToJacSolver	jnt2jac
int	maxiter
unsigned int	nj
JntArray	opt_pos
Eigen::VectorXd	S
Eigen::VectorXd	Sinv
int	svdResult
Eigen::VectorXd	tmp
Eigen::VectorXd	tmp2
Eigen::MatrixXd	U
Eigen::MatrixXd	V
JntArray	weights

Detailed Description

Implementation of a inverse velocity kinematics algorithm based on the generalize pseudo inverse to calculate the velocity transformation from Cartesian to joint space of a general KDL::Chain. It uses a svd-calculation based on householders rotations.

In case of a redundant robot this solver optimizes the following criterium: g=0.5*sum(weight*(Desired_joint_positions - actual_joint_positions))^2 as described in A. Liegeois. Automatic supervisory control of the configuration and behavior of multibody mechanisms. IEEE Transactions on Systems, Man, and Cybernetics, 7(12):868–871, 1977

Definition at line 46 of file chainiksolvervel_pinv_nso.hpp.

Constructor & Destructor Documentation

KDL::ChainIkSolverVel_pinv_nso::ChainIkSolverVel_pinv_nso	(	const Chain &	chain,
		const JntArray &	opt_pos,
		const JntArray &	weights,
		double	eps = `0.00001`,
		int	maxiter = `150`,
		double	alpha = `0.25`
	)

Constructor of the solver

Parameters:

chain	the chain to calculate the inverse velocity kinematics for
opt_pos	the desired positions of the chain used by to resolve the redundancy
weights	the weights applied in the joint space
eps	if a singular value is below this value, its inverse is set to zero, default: 0.00001
maxiter	maximum iterations for the svd calculation, default: 150
alpha	the null-space velocity gain

Definition at line 27 of file chainiksolvervel_pinv_nso.cpp.

KDL::ChainIkSolverVel_pinv_nso::ChainIkSolverVel_pinv_nso	(	const Chain &	chain,
		double	eps = `0.00001`,
		int	maxiter = `150`,
		double	alpha = `0.25`
	)		`[explicit]`

Definition at line 47 of file chainiksolvervel_pinv_nso.cpp.

KDL::ChainIkSolverVel_pinv_nso::~ChainIkSolverVel_pinv_nso ( )

Definition at line 79 of file chainiksolvervel_pinv_nso.cpp.

Member Function Documentation

int KDL::ChainIkSolverVel_pinv_nso::CartToJnt	(	const JntArray &	q_in,
		const Twist &	v_in,
		JntArray &	qdot_out
	)		`[virtual]`

Calculate inverse velocity kinematics, from joint positions and cartesian velocity to joint velocities.

Parameters:

q_in	input joint positions
v_in	input cartesian velocity
qdot_out	output joint velocities

Returns:: if < 0 something went wrong

Implements KDL::ChainIkSolverVel.

Definition at line 84 of file chainiksolvervel_pinv_nso.cpp.

virtual int KDL::ChainIkSolverVel_pinv_nso::CartToJnt	(	const JntArray &	q_init,
		const FrameVel &	v_in,
		JntArrayVel &	q_out
	)		`[inline, virtual]`

not (yet) implemented.

Implements KDL::ChainIkSolverVel.

Definition at line 72 of file chainiksolvervel_pinv_nso.hpp.

const double& KDL::ChainIkSolverVel_pinv_nso::getAlpha ( ) const [inline]

Request null space velocity gain

Returns:: const reference to the null space velocity gain

Definition at line 102 of file chainiksolvervel_pinv_nso.hpp.

const JntArray& KDL::ChainIkSolverVel_pinv_nso::getOptPos ( ) const [inline]

Request the optimal joint positions

Returns:: const reference to the optimal joint positions

Definition at line 91 of file chainiksolvervel_pinv_nso.hpp.

int KDL::ChainIkSolverVel_pinv_nso::getSVDResult ( ) const [inline]

Retrieve the latest return code from the SVD algorithm

Returns:: 0 if CartToJnt() not yet called, otherwise latest SVD result code.

Definition at line 135 of file chainiksolvervel_pinv_nso.hpp.

const JntArray& KDL::ChainIkSolverVel_pinv_nso::getWeights ( ) const [inline]

Request the joint weights for optimization criterion

Returns:: const reference to the joint weights

Definition at line 80 of file chainiksolvervel_pinv_nso.hpp.

int KDL::ChainIkSolverVel_pinv_nso::setAlpha ( const double alpha ) [virtual]

Set null space velocity gain

Parameters:

alpha NUllspace velocity cgain

Definition at line 182 of file chainiksolvervel_pinv_nso.cpp.

int KDL::ChainIkSolverVel_pinv_nso::setOptPos ( const JntArray & opt_pos ) [virtual]

Set optimal joint positions

Parameters:

opt_pos optimal joint positions

Definition at line 174 of file chainiksolvervel_pinv_nso.cpp.

int KDL::ChainIkSolverVel_pinv_nso::setWeights ( const JntArray & weights ) [virtual]

Set joint weights for optimization criterion

Parameters:

weights the joint weights

Definition at line 166 of file chainiksolvervel_pinv_nso.cpp.

void KDL::ChainIkSolverVel_pinv_nso::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::ChainIkSolverVel.

Definition at line 65 of file chainiksolvervel_pinv_nso.cpp.