TransformNDOF Class Reference

Abstract class model an arbitrary N DOF joint.

#include <vpNDOFJoint.h>

List of all members.

Public Member Functions

virtual SE3 GetTransform (const scalarArray &)=0

virtual void GetJacobian (const scalarArray &, se3Array &)

virtual void GetHessian (const scalarArray &, se3DbAry &)

Member Function Documentation

virtual SE3 TransformNDOF::GetTransform ( const scalarArray & ) [pure virtual]

Transform function

virtual void TransformNDOF::GetJacobian	(	const scalarArray &	,
		se3Array &
	)			`[virtual]`

Jacobian function

The Jacobain is defined as $J_i(q) = T(q)^{-1} \frac{\partial T(q)}{\partial q_i} \in se(3)$ If the Jacobian function is not overrided, VP will evaluate the Jacobian using numerical differentiation. The numerical differentiation requires DOF + 1 times of evaluating the transform function in general. Also another potential problem of the numerical differentiation is that it may be very sensitive to the epsilon value. The default epsilon used for numerical differentiation is set as m_rEPS = 1E-4.

virtual void TransformNDOF::GetHessian	(	const scalarArray &	,
		se3DbAry &
	)			`[virtual]`

Hessian function

The Hessian is defined as $H_{ij}(q) = \frac{\partial J_i(q)}{\partial q_j} \in se(3)$

Only the upper triangular part of H will be used. That is, $H_{ij}$ for i > j will not be referenced. if the Hessian function is not overrided , VP will evalute the Hessian based on a numerical differentiation.


Public Member Functions
virtual SE3	GetTransform (const scalarArray &)=0
virtual void	GetJacobian (const scalarArray &, se3Array &)
virtual void	GetHessian (const scalarArray &, se3DbAry &)