Ravelin
Public Types | Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
Ravelin::UNIVERSALJOINT Class Reference

Defines a joint for purely rotational motion. More...

#include <UniversalJointd.h>

Inheritance diagram for Ravelin::UNIVERSALJOINT:
Ravelin::JOINT Ravelin::JOINT Ravelin::virtual_enable_shared_from_this< JOINT > Ravelin::virtual_enable_shared_from_this< JOINT > Ravelin::virtual_enable_shared_from_this< JOINT > Ravelin::virtual_enable_shared_from_this< JOINT > Ravelin::virtual_enable_shared_from_this_base Ravelin::virtual_enable_shared_from_this_base Ravelin::virtual_enable_shared_from_this_base Ravelin::virtual_enable_shared_from_this_base

Public Types

enum  Axis { eAxis1, eAxis2, eAxis1, eAxis2 }
 
enum  Axis { eAxis1, eAxis2, eAxis1, eAxis2 }
 
- Public Types inherited from Ravelin::JOINT
enum  ConstraintType {
  eUnknown, eExplicit, eImplicit, eUnknown,
  eExplicit, eImplicit
}
 
enum  DOFs {
  DOF_1 =0, DOF_2 =1, DOF_3 =2, DOF_4 =3,
  DOF_5 =4, DOF_6 =5, DOF_1 =0, DOF_2 =1,
  DOF_3 =2, DOF_4 =3, DOF_5 =4, DOF_6 =5
}
 
enum  ConstraintType {
  eUnknown, eExplicit, eImplicit, eUnknown,
  eExplicit, eImplicit
}
 
enum  DOFs {
  DOF_1 =0, DOF_2 =1, DOF_3 =2, DOF_4 =3,
  DOF_5 =4, DOF_6 =5, DOF_1 =0, DOF_2 =1,
  DOF_3 =2, DOF_4 =3, DOF_5 =4, DOF_6 =5
}
 

Public Member Functions

 UNIVERSALJOINT ()
 Initializes the joint. More...
 
VECTOR3 get_axis (Axis a) const
 Gets the axis for this joint.
 
void set_axis (const VECTOR3 &axis, Axis a)
 Sets an axis of rotation of this joint (MUST BE CALLED AFTER set_location(.)) More...
 
virtual void update_spatial_axes ()
 Updates the spatial axis for this joint.
 
virtual void determine_q (VECTORN &q)
 Determines (and sets) the value of Q from the axes and the inboard link and outboard link transforms.
 
virtual boost::shared_ptr
< const POSE3 > 		get_induced_pose ()
 Gets the transform induced by this joint.
 
virtual const std::vector
< SVELOCITY > & 		get_spatial_axes ()
 Gets the spatial axes for this joint. More...
 
virtual const std::vector
< SVELOCITY > & 		get_spatial_axes_dot ()
 Gets the derivative of the spatial-axis. More...
 
virtual unsigned num_dof () const
 Gets the number of degrees-of-freedom for this joint.
 
virtual void evaluate_constraints (REAL C[])
 Evaluates the constraint equations.
 
virtual void calc_constraint_jacobian (bool inboard, MATRIXN &Cq)
 Computes the constraint jacobian with respect to a body.
 
virtual void calc_constraint_jacobian_dot (bool inboard, MATRIXN &Cq)
 Computes the time derivative of the constraint jacobian with respect to a body. More...
 
virtual bool is_singular_config () const
 Universal joint is never singular.
 
VECTOR3 get_axis (Axis a) const
 
void set_axis (const VECTOR3 &axis, Axis a)
 
virtual void update_spatial_axes ()
 
virtual void determine_q (VECTORN &q)
 Abstract method to determine the value of Q (joint position) from current transforms.
 
virtual boost::shared_ptr
< const POSE3 > 		get_induced_pose ()
 Abstract method to get the local transform for this joint. More...
 
virtual const std::vector
< SVELOCITY > & 		get_spatial_axes ()
 
virtual const std::vector
< SVELOCITY > & 		get_spatial_axes_dot ()
 Abstract method to get the spatial axes derivatives for this joint. More...
 
virtual unsigned num_dof () const
 Gets the number of degrees-of-freedom for this joint.
 
virtual void evaluate_constraints (REAL C[])
 Evaluates the constraint equations for this joint. More...
 
virtual void calc_constraint_jacobian (bool inboard, MATRIXN &Cq)
 Computes the constraint Jacobian for this joint with respect to the given body. More...
 
virtual void calc_constraint_jacobian_dot (bool inboard, MATRIXN &Cq)
 Computes the time derivative of the constraint Jacobian for this joint with respect to the given body. More...
 
virtual bool is_singular_config () const
 Universal joint is never singular.
 
- Public Member Functions inherited from Ravelin::JOINT
void add_force (const VECTORN &force)
 
void reset_force ()
 
ConstraintType get_constraint_type () const
 
void set_constraint_type (ConstraintType type)
 Sets whether this constraint is implicit or explicit (or unknown)
 
boost::shared_ptr
< ARTICULATED_BODY > 		get_articulated_body ()
 Gets the articulated body corresponding to this body. More...
 
void set_articulated_body (boost::shared_ptr< ARTICULATED_BODY > abody)
 Sets the articulated body corresponding to this body. More...
 
virtual void set_inboard_link (boost::shared_ptr< RIGIDBODY > link, bool update_pose)
 
virtual void set_outboard_link (boost::shared_ptr< RIGIDBODY > link, bool update_pose)
 
void set_location (const VECTOR3 &p, boost::shared_ptr< RIGIDBODY > inboard, boost::shared_ptr< RIGIDBODY > outboard)
 
VECTOR3 get_location (bool use_outboard=false) const
 
virtual void set_inboard_pose (boost::shared_ptr< const POSE3 > inboard_pose, bool update_joint_pose)
 
virtual void set_outboard_pose (boost::shared_ptr< POSE3 > outboard_pose, bool update_joint_pose)
 
virtual void evaluate_constraints_dot (REAL C[])
 
virtual void set_q_tare (const VECTORN &tare)
 
virtual const VECTORN & get_q_tare () const
 
boost::shared_ptr< RIGIDBODY > get_inboard_link () const
 Gets the inboard link for this joint.
 
boost::shared_ptr< RIGIDBODY > get_outboard_link () const
 Gets the outboard link for this joint.
 
unsigned get_index () const
 Gets the joint index (returns UINT_MAX if not set)
 
void set_index (unsigned index)
 Sets the joint index. More...
 
unsigned get_constraint_index () const
 Gets the constraint index for this joint.
 
void set_constraint_index (unsigned idx)
 Sets the constraint index for this joint.
 
void set_coord_index (unsigned index)
 Sets the coordinate index for this joint. More...
 
unsigned get_coord_index () const
 Gets the starting coordinate index for this joint.
 
boost::shared_ptr< const POSE3 > get_pose () const
 Gets the pose of this joint (relative to the inboard pose instead of the outboard pose as returned by get_pose_from_outboard())
 
boost::shared_ptr< const POSE3 > get_pose_from_outboard () const
 Gets the pose of this joint relative to the outboard pose (rather than the inboard pose as returned by get_pose())
 
virtual unsigned num_constraint_eqns () const
 Gets the number of constraint equations for this joint.
 
void add_force (const VECTORN &force)
 
void reset_force ()
 
ConstraintType get_constraint_type () const
 
void set_constraint_type (ConstraintType type)
 Sets whether this constraint is implicit or explicit (or unknown)
 
boost::shared_ptr
< ARTICULATED_BODY > 		get_articulated_body ()
 Gets the articulated body corresponding to this body. More...
 
void set_articulated_body (boost::shared_ptr< ARTICULATED_BODY > abody)
 Sets the articulated body corresponding to this body. More...
 
virtual void set_inboard_link (boost::shared_ptr< RIGIDBODY > link, bool update_pose)
 
virtual void set_outboard_link (boost::shared_ptr< RIGIDBODY > link, bool update_pose)
 
void set_location (const VECTOR3 &p, boost::shared_ptr< RIGIDBODY > inboard, boost::shared_ptr< RIGIDBODY > outboard)
 
VECTOR3 get_location (bool use_outboard=false) const
 
virtual void set_inboard_pose (boost::shared_ptr< const POSE3 > inboard_pose, bool update_joint_pose)
 
virtual void set_outboard_pose (boost::shared_ptr< POSE3 > outboard_pose, bool update_joint_pose)
 
virtual void evaluate_constraints_dot (REAL C[])
 
virtual void set_q_tare (const VECTORN &tare)
 
virtual const VECTORN & get_q_tare () const
 
boost::shared_ptr< RIGIDBODY > get_inboard_link () const
 Gets the inboard link for this joint.
 
boost::shared_ptr< RIGIDBODY > get_outboard_link () const
 Gets the outboard link for this joint.
 
unsigned get_index () const
 Gets the joint index (returns UINT_MAX if not set)
 
void set_index (unsigned index)
 Sets the joint index. More...
 
unsigned get_constraint_index () const
 Gets the constraint index for this joint.
 
void set_constraint_index (unsigned idx)
 Sets the constraint index for this joint.
 
void set_coord_index (unsigned index)
 Sets the coordinate index for this joint. More...
 
unsigned get_coord_index () const
 Gets the starting coordinate index for this joint.
 
boost::shared_ptr< const POSE3 > get_pose () const
 Gets the pose of this joint (relative to the inboard pose instead of the outboard pose as returned by get_pose_from_outboard())
 
boost::shared_ptr< const POSE3 > get_pose_from_outboard () const
 Gets the pose of this joint relative to the outboard pose (rather than the inboard pose as returned by get_pose())
 
virtual unsigned num_constraint_eqns () const
 Gets the number of constraint equations for this joint.
 
- Public Member Functions inherited from Ravelin::virtual_enable_shared_from_this< JOINT >
boost::shared_ptr< JOINT > shared_from_this ()
 
boost::shared_ptr< const JOINT > shared_from_this () const
 

Protected Member Functions

bool assign_axes ()
 
MATRIX3 get_rotation () const
 Gets the (local) transform for this joint.
 
void setup_joint ()
 
bool assign_axes ()
 
MATRIX3 get_rotation () const
 
void setup_joint ()
 
- Protected Member Functions inherited from Ravelin::JOINT
void calc_constraint_jacobian_numeric (bool inboard, MATRIXN &Cq)
 
bool transform_jacobian (MATRIXN &J, bool use_inboard, MATRIXN &output)
 
void invalidate_pose_vectors ()
 
boost::shared_ptr< const POSE3 > get_inboard_pose ()
 
boost::shared_ptr< const POSE3 > get_outboard_pose ()
 
virtual void init_data ()
 Method for initializing all variables in the joint. More...
 
void calc_constraint_jacobian_numeric (bool inboard, MATRIXN &Cq)
 
bool transform_jacobian (MATRIXN &J, bool use_inboard, MATRIXN &output)
 
void invalidate_pose_vectors ()
 
boost::shared_ptr< const POSE3 > get_inboard_pose ()
 
boost::shared_ptr< const POSE3 > get_outboard_pose ()
 
virtual void init_data ()
 Method for initializing all variables in the joint. More...
 

Protected Attributes

VECTOR3 _u [2]
 The local joint axes.
 
VECTOR3 _h2
 The second joint axis in outboard pose frame.
 
std::vector< SVELOCITY > _s_dot
 The derivative of the spatial axis.
 
- Protected Attributes inherited from Ravelin::JOINT
boost::shared_ptr< POSE3 > _Fprime
 The frame induced by the joint.
 
boost::shared_ptr< POSE3 > _F
 The frame of this joint.
 
boost::shared_ptr< POSE3 > _Fb
 The frame of this joint backward from the outboard link.
 
std::vector< SVELOCITY > _s
 The spatial axes (in joint frame) for the joint. More...
 
VECTORN _q_tare
 The stored "tare" value for the initial joint configuration. More...
 
boost::weak_ptr< RIGIDBODY > _inboard_link
 
boost::weak_ptr< RIGIDBODY > _outboard_link
 
boost::weak_ptr< ARTICULATED_BODY > _abody
 
ConstraintType _constraint_type
 
unsigned _joint_idx
 
unsigned _coord_idx
 
unsigned _constraint_idx
 

Additional Inherited Members

- Public Attributes inherited from Ravelin::JOINT
std::string joint_id
 The ID of this joint.
 
VECTORN qdd
 The acceleration of this joint.
 
VECTORN force
 The actuator force (user/controller sets this)
 
VECTORN lambda
 Constraint forces calculated by forward dynamics.
 
VECTORN q
 The position of this joint.
 
VECTORN qd
 The velocity of this joint.
 

Detailed Description

Defines a joint for purely rotational motion.

Constructor & Destructor Documentation

UNIVERSALJOINT::UNIVERSALJOINT ( )

Initializes the joint.

The axes of rotation are each set to [0 0 0]. The inboard and outboard links are set to NULL.

References Ravelin::JOINT::_F, _h2, _s_dot, _u, Ravelin::JOINT::init_data(), num_dof(), and Ravelin::VECTOR3::pose.

Member Function Documentation

virtual void Ravelin::UNIVERSALJOINT::calc_constraint_jacobian ( bool  inboard,
MATRIXN &  Cq 
)
virtual

Computes the constraint Jacobian for this joint with respect to the given body.

Parameters
inboard'true' if the Jacobian is to be computed w.r.t. the inboard link; 'false' for the outboard
Cqa 6 x ndof matrix for the given body (on return)

Implements Ravelin::JOINT.

void UNIVERSALJOINT::calc_constraint_jacobian_dot ( bool  inboard,
MATRIXN &  Cq 
)
virtual

Computes the time derivative of the constraint jacobian with respect to a body.

TODO: implement this

Implements Ravelin::JOINT.

virtual void Ravelin::UNIVERSALJOINT::calc_constraint_jacobian_dot ( bool  inboard,
MATRIXN &  Cq 
)
virtual

Computes the time derivative of the constraint Jacobian for this joint with respect to the given body.

Parameters
inboard'true' if the Jacobian is to be computed w.r.t. the inboard link; 'false' for the outboard
Cqa 6 x ndof matrix for the given body (on return)

Implements Ravelin::JOINT.

virtual void Ravelin::UNIVERSALJOINT::evaluate_constraints ( REAL  C[])
virtual

Evaluates the constraint equations for this joint.

When the joint constraints are exactly satisfied, the result will be the zero vector.

Parameters
Ca vector of size num_constraint_eqns(); contains the evaluation (on return)
Note
only used by maximal-coordinate articulated bodies

Implements Ravelin::JOINT.

virtual boost::shared_ptr<const POSE3> Ravelin::UNIVERSALJOINT::get_induced_pose ( )
virtual

Abstract method to get the local transform for this joint.

The local transform for the joint transforms the coordinate frame attached to the joint center and aligned with the inner link frame.

Implements Ravelin::JOINT.

const vector< SVELOCITY > & UNIVERSALJOINT::get_spatial_axes ( )
virtual

Gets the spatial axes for this joint.

Note
these spatial axes are not constant, unlike many joints.

Reimplemented from Ravelin::JOINT.

References Ravelin::JOINT::_q_tare, Ravelin::JOINT::_s, _u, Ravelin::JOINT::get_pose(), and Ravelin::JOINT::q.

virtual const std::vector<SVELOCITY>& Ravelin::UNIVERSALJOINT::get_spatial_axes_dot ( )
virtual

Abstract method to get the spatial axes derivatives for this joint.

Only applicable for reduced-coordinate articulated bodies

Implements Ravelin::JOINT.

const vector< SVELOCITY > & UNIVERSALJOINT::get_spatial_axes_dot ( )
virtual

Gets the derivative of the spatial-axis.

Note
these spatial axes are not constant, unlike many joints.

Implements Ravelin::JOINT.

References Ravelin::JOINT::_q_tare, _s_dot, _u, Ravelin::JOINT::get_pose(), Ravelin::JOINT::q, and Ravelin::JOINT::qd.

void UNIVERSALJOINT::set_axis ( const VECTOR3 &  axis,
Axis  a 
)

Sets an axis of rotation of this joint (MUST BE CALLED AFTER set_location(.))

The local axis for this joint does not take the orientation of the inboard link into account; thus, if the orientation of the inboard link changes, then the local axis remains constant.

Parameters
axisa unit vector
See Also
get_axis_global()
set_axis_global()

References _h2, _u, Ravelin::JOINT::get_pose(), and update_spatial_axes().

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