Recursive Newton Euler ID solver with composite rigid body inertia. More...

#include <KdlChainIdInertia.h>

Public Member Functions
int	CartToJnt (const KDL::JntArray &q, const KDL::JntArray &q_dot, const KDL::JntArray &q_dotdot, const KDL::Wrenches &f_ext, KDL::JntArray &torques, KDL::JntArray &Hv)
	KdlChainIdInertia (const KDL::Chain &chain, KDL::Vector grav)
	Constructor for KdlChainIdInertia.
	~KdlChainIdInertia ()
Private Attributes
std::vector< KDL::Twist >	a
KDL::Twist	ag
KDL::Chain	chain
std::vector< KDL::Wrench >	f
KDL::Wrench	Fis
std::vector < KDL::RigidBodyInertia >	Ii
unsigned int	nj
unsigned int	ns
std::vector< KDL::Twist >	S
std::vector< KDL::Twist >	v
std::vector< KDL::Frame >	X

Detailed Description

Recursive Newton Euler ID solver with composite rigid body inertia.

The algorithm implementation is based on the book "Rigid Body Dynamics Algorithms" of Roy Featherstone, 2008 (ISBN:978-0-387-74314-1) See pages 96 and 107 for the pseudo-code.

It calculates the torques and composite inertias 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. The composite inertias calculated are equivalent to the diagonal of the joint space inertia matrix, H.

Definition at line 24 of file KdlChainIdInertia.h.

Constructor & Destructor Documentation

KdlChainIdInertia::KdlChainIdInertia	(	const KDL::Chain &	chain,
		KDL::Vector	grav
	)

Constructor for KdlChainIdInertia.

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

Parameters:

chain	The kinematic chain to calculate the inverse dynamics for, an internal copy will be made.
grav	The gravity vector to use during the calculation.
grav

Definition at line 14 of file KdlChainIdInertia.cpp.

KdlChainIdInertia::~KdlChainIdInertia ( ) [inline]

Definition at line 32 of file KdlChainIdInertia.h.

Member Function Documentation

int KdlChainIdInertia::CartToJnt	(	const KDL::JntArray &	q,
		const KDL::JntArray &	q_dot,
		const KDL::JntArray &	q_dotdot,
		const KDL::Wrenches &	f_ext,
		KDL::JntArray &	torques,
		KDL::JntArray &	Hv
	)

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
Hv	The composite rigid body inertia each joint sees
q	Position
q_dot	Velocity
q_dotdot	Acceleration
forceExt
torques
Hv