taoJointSpherical Class Reference

Spherical joint class for articulated bodyThis provides a spherical joint for articulated body dynamics. More...

#include <taoJoint.h>

Inheritance diagram for taoJointSpherical:

Collaboration diagram for taoJointSpherical:

Public Member Functions
virtual deInt	getDOF ()
virtual void	reset ()
virtual taoVarSpherical *	getVarSpherical ()
virtual taoVarSpherical const *	getVarSpherical () const
virtual void	setABJoint (taoABJoint *joint)
virtual taoABJoint *	getABJoint ()
virtual taoABJoint const *	getABJoint () const
virtual void	addQdelta ()
virtual void	addDQdelta ()
virtual void	zeroTau ()
virtual void	zeroDDQ ()
virtual void	zeroDQ ()
virtual void	zeroQ ()
virtual void	setTau (const deFloat *v)
virtual void	setDDQ (const deFloat *v)
virtual void	setDQ (const deFloat *v)
virtual void	setQ (const deFloat *v)
virtual void	getTau (deFloat *v) const
virtual void	getDDQ (deFloat *v) const
virtual void	getDQ (deFloat *v) const
virtual void	getQ (deFloat *v) const
virtual void	clampDQ ()
virtual void	integrate (const deFloat dt)
virtual void	updateFrameLocal (deFrame *local)
virtual deMatrix3 *	getJg ()
virtual void	getJgColumns (deVector6 *Jg_columns) const
virtual void	setDVar (taoDVar *var)
virtual taoDVar *	getDVar ()
virtual taoDVar const *	getDVar () const
void	setType (scl::EJointType t)
scl::EJointType	getType () const
void	setDQclamp (deInt b)
deInt	getDQclamp ()
void	setNext (taoJoint *joint)
taoJoint *	getNext ()
virtual void	setDQmax (deFloat dq)
virtual deFloat	getDQmax ()
virtual void	setDamping (deFloat d)
virtual deFloat	getDamping ()
virtual void	setInertia (deFloat i)
virtual deFloat	getInertia ()

Public Attributes
std::string	name_

Protected Attributes
taoABJointSpherical *	_abJoint

Detailed Description

Spherical joint class for articulated body

This provides a spherical joint for articulated body dynamics.

See Also

taoJoint

Member Function Documentation

void taoJointSpherical::addQdelta ( )

virtual

Another example of obfuscated code. The one above code probably does the same thing.

Implements taoDJoint.

virtual void taoJointSpherical::getDDQ ( deFloat *  v ) const

inlinevirtual

Note

pointer semantics to support more than one DOF

Implements taoJoint.

virtual void taoJointSpherical::getDQ ( deFloat *  v ) const

inlinevirtual

Note

pointer semantics to support more than one DOF

Implements taoJoint.

deMatrix3 * taoJointSpherical::getJg ( )

virtual

The "documentation" used to say this (whatever that means exactly): "notice that in spherical joints the position components of the Jacobian are zero therefore, to build a 6x3 matrix the upper 3x3 needs to be set to zero and the lower needs to be set the return of this function".

One thing the documentation did not say is that the returned pointer is an array with two elements. getJg()[0] contains something like (I'm still figuring it out from the code...) the contribution of the joint to the translational velocity, and getJg()[0] contains the rotational part, both dependent on whatever frame got passed to taoABJointSpherical::compute_Jg() previously. taoABJointSpherical::compute_Jg() gets called by taoABNodeNOJ1::globalJacobian() or taoABNodeNOJn::globalJacobian(), which get called by taoABDynamics::globalJacobianOut() and taoABDynamics::compute_Jg_Omega_H(), both of which pass taoDNode::frameGlobal() into it (it can get expressed in successively retracted frames though during the iteration over all the joints of a node). taoDynamics::globalJacobian() seems to be the top-level entry point for that chain of calls, so whatever node (and its global frame) you pass to it will be used throughout the recursion.

Note

This method is retained mainly for backwards compatibility, you should use getJgColumns() instead, which does the necessary operations to inject the positional components. Looking at the taoJointDOF1 version, by analogy this method probably returns the Jacobian contribution of this joint, expressed in the global frame. Someone chose to return it as a 3x3 matrix because they thought it was neat from the point of view of this class, but it actually makes it hard to polymorphically mix joint types, making it completely pointless to declare this method virtual.

void taoJointSpherical::getJgColumns ( deVector6 *  Jg_columns ) const

virtual

You need to pass in an array of three deVector6 instances, because spherical joints have three degrees of (velocity) freedom. Note that getDOF() returns three, so you can use the polymorphic form.

Implements taoJoint.

virtual void taoJointSpherical::getQ ( deFloat *  v ) const

inlinevirtual

Note

pointer semantics to support more than one DOF

Implements taoJoint.

virtual void taoJointSpherical::getTau ( deFloat *  v ) const

inlinevirtual

Note

pointer semantics to support more than one DOF

Implements taoJoint.

virtual void taoJointSpherical::setDDQ ( const deFloat *  v )

inlinevirtual

Note

pointer semantics to support more than one DOF

Implements taoJoint.

virtual void taoJointSpherical::setDQ ( const deFloat *  v )

inlinevirtual

Note

pointer semantics to support more than one DOF

Implements taoJoint.

virtual void taoJointSpherical::setQ ( const deFloat *  v )

inlinevirtual

Note

pointer semantics to support more than one DOF

Implements taoJoint.

virtual void taoJointSpherical::setTau ( const deFloat *  v )

inlinevirtual

Note

pointer semantics to support more than one DOF

Implements taoJoint.

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The documentation for this class was generated from the following files:

• /home/samir/Code/control/scl.git/src/scl/dynamics/tao/tao/dynamics/taoJoint.h
• /home/samir/Code/control/scl.git/src/scl/dynamics/tao/tao/dynamics/taoJoint.cpp