Base class for all joints. More...

#include <physics/physics.hh>

Inherits Base.

Inherited by BulletJoint, DARTJoint, ODEJoint, and SimbodyJoint.

Public Types
enum	Attribute { FUDGE_FACTOR, SUSPENSION_ERP, SUSPENSION_CFM, STOP_ERP, STOP_CFM, ERP, CFM, FMAX, VEL, HI_STOP, LO_STOP }
	Joint attribute types. More...

enum	EntityType { BASE = 0x00000000, ENTITY = 0x00000001, MODEL = 0x00000002, LINK = 0x00000004, COLLISION = 0x00000008, LIGHT = 0x00000010, VISUAL = 0x00000020, JOINT = 0x00000040, BALL_JOINT = 0x00000080, HINGE2_JOINT = 0x00000100, HINGE_JOINT = 0x00000200, SLIDER_JOINT = 0x00000400, SCREW_JOINT = 0x00000800, UNIVERSAL_JOINT = 0x00001000, GEARBOX_JOINT = 0x00002000, FIXED_JOINT = 0x00004000, ACTOR = 0x00008000, SHAPE = 0x00010000, BOX_SHAPE = 0x00020000, CYLINDER_SHAPE = 0x00040000, HEIGHTMAP_SHAPE = 0x00080000, MAP_SHAPE = 0x00100000, MULTIRAY_SHAPE = 0x00200000, RAY_SHAPE = 0x00400000, PLANE_SHAPE = 0x00800000, SPHERE_SHAPE = 0x01000000, MESH_SHAPE = 0x02000000, POLYLINE_SHAPE = 0x04000000, SENSOR_COLLISION = 0x10000000 }
	Unique identifiers for all entity types. More...

Public Member Functions
	Joint (BasePtr _parent)
	Constructor. More...

virtual	~Joint ()
	Destructor. More...

void	AddChild (BasePtr _child)
	Add a child to this entity. More...

void	AddType (EntityType _type)
	Add a type specifier. More...

virtual ignition::math::Vector3d	Anchor (const unsigned int _index) const =0
	Get the anchor point. More...

ignition::math::Pose3d	AnchorErrorPose () const
	Get pose offset between anchor pose on child and parent, expressed in the parent link frame. More...

virtual void	ApplyStiffnessDamping ()
	Callback to apply spring stiffness and viscous damping effects to joint. More...

virtual bool	AreConnected (LinkPtr _one, LinkPtr _two) const =0
	Determines of the two bodies are connected by a joint. More...

virtual void	Attach (LinkPtr _parent, LinkPtr _child)
	Attach the two bodies with this joint. More...

ignition::math::Quaterniond	AxisFrame (const unsigned int _index) const
	Get orientation of reference frame for specified axis, relative to world frame. More...

ignition::math::Quaterniond	AxisFrameOffset (const unsigned int _index) const
	Get orientation of joint axis reference frame relative to joint frame. More...

virtual void	CacheForceTorque ()
	Cache Joint Force Torque Values if necessary for physics engine. More...

double	CheckAndTruncateForce (unsigned int _index, double _effort)
	check if the force against velocityLimit and effortLimit, truncate if necessary. More...

template<typename T >
event::ConnectionPtr	ConnectJointUpdate (T _subscriber)
	Connect a boost::slot the the joint update signal. More...

virtual void	Detach ()
	Detach this joint from all links. More...

void	DisconnectJointUpdate (event::ConnectionPtr &_conn) GAZEBO_DEPRECATED(8.0)
	Disconnect a boost::slot the the joint update signal. More...

virtual unsigned int	DOF () const =0
	Get the number of degrees of freedom for this joint. More...

virtual void	FillMsg (msgs::Joint &_msg)
	Fill a joint message. More...

virtual void	Fini ()
	Finialize the object. More...

virtual math::Vector3	GetAnchor (unsigned int _index) const GAZEBO_DEPRECATED(8.0)
	Get the anchor point. More...

math::Pose	GetAnchorErrorPose () const GAZEBO_DEPRECATED(8.0)
	Get pose offset between anchor pose on child and parent, expressed in the parent link frame. More...

math::Angle	GetAngle (unsigned int _index) const GAZEBO_DEPRECATED(8.0)
	Get the angle of rotation of an axis(index). More...

virtual unsigned int	GetAngleCount () const GAZEBO_DEPRECATED(8.0)
	Get the angle count. More...

math::Quaternion	GetAxisFrame (unsigned int _index) const GAZEBO_DEPRECATED(8.0)
	Get orientation of reference frame for specified axis, relative to world frame. More...

math::Quaternion	GetAxisFrameOffset (unsigned int _index) const GAZEBO_DEPRECATED(8.0)
	Get orientation of joint axis reference frame relative to joint frame. More...

BasePtr	GetByName (const std::string &_name)
	Get by name. More...

BasePtr	GetChild (unsigned int _i) const
	Get a child by index. More...

BasePtr	GetChild (const std::string &_name)
	Get a child by name. More...

LinkPtr	GetChild () const
	Get the child link. More...

unsigned int	GetChildCount () const
	Get the number of children. More...

double	GetDamping (unsigned int _index)
	Returns the current joint damping coefficient. More...

virtual double	GetEffortLimit (unsigned int _index)
	Get the effort limit on axis(index). More...

virtual double	GetForce (unsigned int _index)

virtual JointWrench	GetForceTorque (unsigned int _index)=0
	get internal force and torque values at a joint. More...

virtual math::Vector3	GetGlobalAxis (unsigned int _index) const GAZEBO_DEPRECATED(8.0)
	Get the axis of rotation in global cooridnate frame. More...

virtual math::Angle	GetHighStop (unsigned int _index) GAZEBO_DEPRECATED(8.0)
	Get the high stop of an axis(index). More...

uint32_t	GetId () const
	Return the ID of this entity. More...

double	GetInertiaRatio (const unsigned int _index) const
	Computes moment of inertia (MOI) across a specified joint axis. More...

double	GetInertiaRatio (const math::Vector3 &_axis) const GAZEBO_DEPRECATED(8.0)
	Computes moment of inertia (MOI) across an arbitrary axis specified in the world frame. More...

math::Pose	GetInitialAnchorPose () const GAZEBO_DEPRECATED(8.0)
	Get initial Anchor Pose specified by model <joint><pose>...</pose></joint> More...

virtual LinkPtr	GetJointLink (unsigned int _index) const =0
	Get the link to which the joint is attached according the _index. More...

virtual math::Vector3	GetLinkForce (unsigned int _index) const GAZEBO_DEPRECATED(8.0)
	Get the forces applied to the center of mass of a physics::Link due to the existence of this Joint. More...

virtual math::Vector3	GetLinkTorque (unsigned int _index) const GAZEBO_DEPRECATED(8.0)
	Get the torque applied to the center of mass of a physics::Link due to the existence of this Joint. More...

math::Vector3	GetLocalAxis (unsigned int _index) const GAZEBO_DEPRECATED(8.0)
	Get the axis of rotation. More...

math::Angle	GetLowerLimit (unsigned int _index) const GAZEBO_DEPRECATED(8.0)
	: get the joint lower limit (replaces GetLowStop and GetHighStop) More...

virtual math::Angle	GetLowStop (unsigned int _index) GAZEBO_DEPRECATED(8.0)
	Get the low stop of an axis(index). More...

msgs::Joint::Type	GetMsgType () const
	Get the joint type as msgs::Joint::Type. More...

std::string	GetName () const
	Return the name of the entity. More...

virtual double	GetParam (const std::string &_key, unsigned int _index)
	Get a non-generic parameter for the joint. More...

LinkPtr	GetParent () const
	Get the parent link. More...

int	GetParentId () const
	Return the ID of the parent. More...

math::Pose	GetParentWorldPose () const GAZEBO_DEPRECATED(8.0)
	Get anchor pose on parent link relative to world frame. More...

bool	GetSaveable () const
	Get whether the object should be "saved", when the user selects to save the world to xml. More...

std::string	GetScopedName (bool _prependWorldName=false) const
	Return the name of this entity with the model scope model1::...::modelN::entityName. More...

virtual const sdf::ElementPtr	GetSDF ()
	Get the SDF values for the object. More...

double	GetSpringReferencePosition (unsigned int _index) const
	Get joint spring reference position. More...

double	GetStiffness (unsigned int _index)
	Returns the current joint spring stiffness coefficient. More...

double	GetStopDissipation (unsigned int _index) const
	Get joint stop dissipation. More...

double	GetStopStiffness (unsigned int _index) const
	Get joint stop stiffness. More...

unsigned int	GetType () const
	Get the full type definition. More...

math::Angle	GetUpperLimit (unsigned int _index) const GAZEBO_DEPRECATED(8.0)
	: get the joint upper limit (replacee GetLowStop and GetHighStop) More...

virtual double	GetVelocity (unsigned int _index) const =0
	Get the rotation rate of an axis(index) More...

virtual double	GetVelocityLimit (unsigned int _index)
	Get the velocity limit on axis(index). More...

const WorldPtr &	GetWorld () const
	Get the World this object is in. More...

double	GetWorldEnergyPotentialSpring (unsigned int _index) const
	Returns this joint's spring potential energy, based on the reference position of the spring. More...

math::Pose	GetWorldPose () const GAZEBO_DEPRECATED(8.0)
	Get pose of joint frame relative to world frame. More...

virtual ignition::math::Vector3d	GlobalAxis (unsigned int _index) const =0
	Get the axis of rotation in global cooridnate frame. More...

bool	HasType (const EntityType &_t) const
	Returns true if this object's type definition has the given type. More...

double	InertiaRatio (const ignition::math::Vector3d &_axis) const
	Computes moment of inertia (MOI) across an arbitrary axis specified in the world frame. More...

virtual void	Init ()
	Initialize a joint. More...

ignition::math::Pose3d	InitialAnchorPose () const
	Get initial Anchor Pose specified by model <joint><pose>...</pose></joint> More...

bool	IsSelected () const
	True if the entity is selected by the user. More...

virtual ignition::math::Vector3d	LinkForce (const unsigned int _index) const =0
	Get the forces applied to the center of mass of a physics::Link due to the existence of this Joint. More...

virtual ignition::math::Vector3d	LinkTorque (const unsigned int _index) const =0
	Get the torque applied to the center of mass of a physics::Link due to the existence of this Joint. More...

void	Load (LinkPtr _parent, LinkPtr _child, const math::Pose &_pose) GAZEBO_DEPRECATED(8.0)
	Set pose, parent and child links of a physics::Joint. More...

void	Load (LinkPtr _parent, LinkPtr _child, const ignition::math::Pose3d &_pose)
	Set pose, parent and child links of a physics::Joint. More...

virtual void	Load (sdf::ElementPtr _sdf)
	Load physics::Joint from a SDF sdf::Element. More...

ignition::math::Vector3d	LocalAxis (const unsigned int _index) const
	Get the axis of rotation. More...

virtual double	LowerLimit (unsigned int _index=0) const
	Get the joint's lower limit. More...

bool	operator== (const Base &_ent) const
	Returns true if the entities are the same. More...

ignition::math::Pose3d	ParentWorldPose () const
	Get anchor pose on parent link relative to world frame. More...

virtual double	Position (const unsigned int _index=0) const final
	Get the position of an axis according to its index. More...

void	Print (const std::string &_prefix)
	Print this object to screen via gzmsg. More...

virtual void	RemoveChild (unsigned int _id)
	Remove a child from this entity. More...

void	RemoveChild (const std::string &_name)
	Remove a child by name. More...

void	RemoveChild (physics::BasePtr _child)
	Remove a child by pointer. More...

void	RemoveChildren ()
	Remove all children. More...

virtual void	Reset ()
	Reset the joint. More...

virtual void	Reset (Base::EntityType _resetType)
	Calls recursive Reset on one of the Base::EntityType's. More...

virtual void	SetAnchor (unsigned int _index, const math::Vector3 &_anchor) GAZEBO_DEPRECATED(8.0)
	Set the anchor point. More...

virtual void	SetAnchor (const unsigned int _index, const ignition::math::Vector3d &_anchor)=0
	Set the anchor point. More...

virtual void	SetAxis (unsigned int _index, const math::Vector3 &_axis) GAZEBO_DEPRECATED(8.0)
	Set the axis of rotation where axis is specified in local joint frame. More...

virtual void	SetAxis (const unsigned int _index, const ignition::math::Vector3d &_axis)=0
	Set the axis of rotation where axis is specified in local joint frame. More...

virtual void	SetDamping (unsigned int _index, double _damping)=0
	Set the joint damping. More...

virtual void	SetEffortLimit (unsigned int _index, double _effort)
	Set the effort limit on a joint axis. More...

virtual void	SetForce (unsigned int _index, double _effort)=0
	Set the force applied to this physics::Joint. More...

virtual bool	SetHighStop (unsigned int _index, const math::Angle &_angle) GAZEBO_DEPRECATED(8.0)
	Set the high stop of an axis(index). More...

void	SetLowerLimit (unsigned int _index, math::Angle _limit) GAZEBO_DEPRECATED(8.0)
	: set the joint lower limit (replaces SetLowStop and SetHighStop) More...

virtual void	SetLowerLimit (const unsigned int _index, const double _limit)
	Set the joint's lower limit. More...

virtual bool	SetLowStop (unsigned int _index, const math::Angle &_angle) GAZEBO_DEPRECATED(8.0)
	Set the low stop of an axis(index). More...

void	SetModel (ModelPtr _model)
	Set the model this joint belongs too. More...

virtual void	SetName (const std::string &_name)
	Set the name of the entity. More...

virtual bool	SetParam (const std::string &_key, unsigned int _index, const boost::any &_value)=0
	Set a non-generic parameter for the joint. More...

void	SetParent (BasePtr _parent)
	Set the parent. More...

virtual bool	SetPosition (unsigned int _index, double _position)
	The child links of this joint are updated based on desired position. More...

virtual void	SetProvideFeedback (bool _enable)
	Set whether the joint should generate feedback. More...

void	SetSaveable (bool _v)
	Set whether the object should be "saved", when the user selects to save the world to xml. More...

virtual bool	SetSelected (bool _show)
	Set whether this entity has been selected by the user through the gui. More...

void	SetState (const JointState &_state)
	Set the joint state. More...

virtual void	SetStiffness (unsigned int _index, const double _stiffness)=0
	Set the joint spring stiffness. More...

virtual void	SetStiffnessDamping (unsigned int _index, double _stiffness, double _damping, double _reference=0)=0
	Set the joint spring stiffness. More...

void	SetStopDissipation (unsigned int _index, double _dissipation)
	Set joint stop dissipation. More...

void	SetStopStiffness (unsigned int _index, double _stiffness)
	Set joint stop stiffness. More...

void	SetUpperLimit (unsigned int _index, math::Angle _limit) GAZEBO_DEPRECATED(8.0)
	: set the joint upper limit (replacee GetLowStop and GetHighStop) More...

virtual void	SetUpperLimit (const unsigned int _index, const double _limit)
	Set the joint's upper limit. More...

virtual void	SetVelocity (unsigned int _index, double _vel)=0
	Set the velocity of an axis(index). More...

virtual void	SetVelocityLimit (unsigned int _index, double _velocity)
	Set the velocity limit on a joint axis. More...

void	SetWorld (const WorldPtr &_newWorld)
	Set the world this object belongs to. More...

std::string	TypeStr () const
	Get the string name for the entity type. More...

void	Update ()
	Update the joint. More...

virtual void	UpdateParameters (sdf::ElementPtr _sdf)
	Update the parameters using new sdf values. More...

virtual double	UpperLimit (const unsigned int _index=0) const
	Get the joint's upper limit. More...

common::URI	URI () const
	Return the common::URI of this entity. More...

ignition::math::Pose3d	WorldPose () const
	Get pose of joint frame relative to world frame. More...

Protected Member Functions
ignition::math::Pose3d	ChildLinkPose (const unsigned int _index, const double _position)
	internal function to help us compute child link pose if a joint position change is applied. More...

math::Pose	ComputeChildLinkPose (unsigned int _index, double _position) GAZEBO_DEPRECATED(8.0)
	internal function to help us compute child link pose if a joint position change is applied. More...

void	ComputeScopedName ()
	Compute the scoped name of this object based on its parents. More...

bool	FindAllConnectedLinks (const LinkPtr &_originalParentLink, Link_V &_connectedLinks)
	internal helper to find all links connected to the child link branching out from the children of the child link and any parent of the child link other than the parent link through this joint. More...

virtual math::Angle	GetAngleImpl (unsigned int _index) const GAZEBO_DEPRECATED(8.0)
	Get the angle of an axis helper function. More...

virtual double	PositionImpl (const unsigned int _index=0) const =0
	Helper function to get the position of an axis. More...

virtual void	RegisterIntrospectionItems ()
	Register items in the introspection service. More...

bool	SetPositionMaximal (unsigned int _index, double _position)
	Helper function for maximal coordinate solver SetPosition. More...

bool	SetVelocityMaximal (unsigned int _index, double _velocity)
	Helper function for maximal coordinate solver SetVelocity. More...

virtual void	UnregisterIntrospectionItems ()
	Unregister items in the introspection service. More...

Protected Attributes
LinkPtr	anchorLink
	Anchor link. More...

ignition::math::Vector3d	anchorPos
	Anchor pose. More...

ignition::math::Pose3d	anchorPose
	Anchor pose specified in SDF <joint><pose> tag. More...

gazebo::event::ConnectionPtr	applyDamping
	apply damping for adding viscous damping forces on updates More...

bool	axisParentModelFrame [2]
	Flags that are set to true if an axis value is expressed in the parent model frame. More...

LinkPtr	childLink
	The first link this joint connects to. More...

Base_V	children
	Children of this entity. More...

double	dissipationCoefficient [2]
	joint viscous damping coefficient More...

double	effortLimit [2]
	Store Joint effort limit as specified in SDF. More...

std::vector< common::URI >	introspectionItems
	All the introspection items regsitered for this. More...

double	lowerLimit [2]
	Store Joint position lower limit as specified in SDF. More...

ModelPtr	model
	Pointer to the parent model. More...

BasePtr	parent
	Parent of this entity. More...

ignition::math::Pose3d	parentAnchorPose
	Anchor pose relative to parent link frame. More...

LinkPtr	parentLink
	The second link this joint connects to. More...

bool	provideFeedback
	Provide Feedback data for contact forces. More...

sdf::ElementPtr	sdf
	The SDF values for this object. More...

double	springReferencePosition [2]
	joint spring reference (zero load) position More...

double	stiffnessCoefficient [2]
	joint stiffnessCoefficient More...

double	upperLimit [2]
	Store Joint position upper limit as specified in SDF. More...

double	velocityLimit [2]
	Store Joint velocity limit as specified in SDF. More...

WorldPtr	world
	Pointer to the world. More...

JointWrench	wrench
	Cache Joint force torque values in case physics engine clears them at the end of update step. More...

Detailed Description

Base class for all joints.

Member Enumeration Documentation

enum Attribute

Joint attribute types.

Enumerator
FUDGE_FACTOR	Fudge factor.
SUSPENSION_ERP	Suspension error reduction parameter.
SUSPENSION_CFM	Suspension constraint force mixing.
STOP_ERP	Stop limit error reduction parameter.
STOP_CFM	Stop limit constraint force mixing.
ERP	Error reduction parameter.
CFM	Constraint force mixing.
FMAX	Maximum force.
VEL	Velocity.
HI_STOP	Upper joint limit.
LO_STOP	Lower joint limit.

enum EntityType

inherited

Unique identifiers for all entity types.

Enumerator
BASE	Base type.
ENTITY	Entity type.
MODEL	Model type.
LINK	Link type.
COLLISION	Collision type.
LIGHT	Light type.
VISUAL	Visual type.
JOINT	Joint type.
BALL_JOINT	BallJoint type.
HINGE2_JOINT	Hing2Joint type.
HINGE_JOINT	HingeJoint type.
SLIDER_JOINT	SliderJoint type.
SCREW_JOINT	ScrewJoint type.
UNIVERSAL_JOINT	UniversalJoint type.
GEARBOX_JOINT	GearboxJoint type.
FIXED_JOINT	FixedJoint type.
ACTOR	Actor type.
SHAPE	Shape type.
BOX_SHAPE	BoxShape type.
CYLINDER_SHAPE	CylinderShape type.
HEIGHTMAP_SHAPE	HeightmapShape type.
MAP_SHAPE	MapShape type.
MULTIRAY_SHAPE	MultiRayShape type.
RAY_SHAPE	RayShape type.
PLANE_SHAPE	PlaneShape type.
SPHERE_SHAPE	SphereShape type.
MESH_SHAPE	MeshShape type.
POLYLINE_SHAPE	PolylineShape type.
SENSOR_COLLISION	Indicates a collision shape used for sensing.

Constructor & Destructor Documentation

Joint ( BasePtr _parent )

explicit

Constructor.

Parameters

[in] Joint parent

virtual ~Joint ( )

virtual

Destructor.

Member Function Documentation

void AddChild ( BasePtr _child )

inherited

Add a child to this entity.

Parameters

[in] _child Child entity.

void AddType ( EntityType _type )

inherited

Add a type specifier.

Parameters

[in] _type New type to append to this objects type definition.

virtual ignition::math::Vector3d Anchor ( const unsigned int _index ) const

pure virtual

Get the anchor point.

Parameters

[in] _index Index of the axis.

Returns: Anchor value for the axis.

Implemented in BulletJoint, SimbodyJoint, ODEHinge2Joint, BulletBallJoint, BulletHinge2Joint, BulletScrewJoint, BulletUniversalJoint, BulletHingeJoint, ODEGearboxJoint, ODEHingeJoint, DARTFixedJoint, DARTHinge2Joint, DARTHingeJoint, ODESliderJoint, SimbodyUniversalJoint, DARTUniversalJoint, SimbodyHinge2Joint, DARTBallJoint, DARTSliderJoint, ODEFixedJoint, DARTScrewJoint, ODEBallJoint, ODEUniversalJoint, ODEScrewJoint, and SimbodyBallJoint.

ignition::math::Pose3d AnchorErrorPose ( ) const

Get pose offset between anchor pose on child and parent, expressed in the parent link frame.

This can be used to compute the bilateral constraint error.

Returns: Pose offset between anchor pose on child and parent, in parent link frame.

virtual void ApplyStiffnessDamping ( )

virtual

Callback to apply spring stiffness and viscous damping effects to joint.

: rename to ApplySpringStiffnessDamping()

Reimplemented in ODEJoint, and BulletJoint.

virtual bool AreConnected	(	LinkPtr	_one,
		LinkPtr	_two
	)		const

pure virtual

Determines of the two bodies are connected by a joint.

Parameters

[in]	_one	First link.
[in]	_two	Second link.

Returns: True if the two links are connected by a joint.

Implemented in ODEJoint, BulletJoint, DARTJoint, and SimbodyJoint.

virtual void Attach	(	LinkPtr	_parent,
		LinkPtr	_child
	)

virtual

Attach the two bodies with this joint.

Parameters

[in]	_parent	Parent link.
[in]	_child	Child link.

Reimplemented in ODEJoint, ODEFixedJoint, and DARTJoint.

ignition::math::Quaterniond AxisFrame ( const unsigned int _index ) const

Get orientation of reference frame for specified axis, relative to world frame.

The value of axisParentModelFrame is used to determine the appropriate frame.

Parameters

[in] _index joint axis index.

Returns: Orientation of axis frame relative to world frame.

ignition::math::Quaterniond AxisFrameOffset ( const unsigned int _index ) const

Get orientation of joint axis reference frame relative to joint frame.

This should always return identity unless flag use_parent_model_frame is true in sdf 1.5 or using sdf 1.4-, i.e. bug described in issue #494 is present. In addition, if use_parent_model_frame is true, and the parent link of the joint is world, the axis is defined in the world frame. The value of axisParentModelFrame is used to determine the appropriate frame internally.

Parameters

[in] _index joint axis index.

Returns: Orientation of axis frame relative to joint frame. If supplied _index is out of range, or use_parent_model_frame is not true, this function returns identity rotation quaternion.

virtual void CacheForceTorque ( )

virtual

Cache Joint Force Torque Values if necessary for physics engine.

Reimplemented in SimbodyJoint, BulletJoint, ODEJoint, and DARTJoint.

double CheckAndTruncateForce	(	unsigned int	_index,
		double	_effort
	)

check if the force against velocityLimit and effortLimit, truncate if necessary.

Parameters

[in]	_index	Index of the axis.
[in]	_effort	Force value.

Returns: truncated effort

ignition::math::Pose3d ChildLinkPose	(	const unsigned int	_index,
		const double	_position
	)

protected

internal function to help us compute child link pose if a joint position change is applied.

Parameters

[in]	_index	axis index
[in]	_position	new joint position

Returns: new child link pose at new joint position.

math::Pose ComputeChildLinkPose	(	unsigned int	_index,
		double	_position
	)

protected

internal function to help us compute child link pose if a joint position change is applied.

Parameters

[in]	_index	axis index
[in]	_position	new joint position

Returns: new child link pose at new joint position.

Deprecated:: See function that returns ignition math.

void ComputeScopedName ( )

protectedinherited

Compute the scoped name of this object based on its parents.

See Also: Base::GetScopedName

event::ConnectionPtr ConnectJointUpdate ( T _subscriber )

inline

Connect a boost::slot the the joint update signal.

Parameters

[in] _subscriber Callback for the connection.

Returns: Connection pointer, which must be kept in scope.

References EventT< T >::Connect().

virtual void Detach ( )

virtual

Detach this joint from all links.

Reimplemented in ODEJoint, DARTJoint, BulletJoint, and SimbodyJoint.

void DisconnectJointUpdate ( event::ConnectionPtr & _conn )

inline

Disconnect a boost::slot the the joint update signal.

Parameters

[in] _conn Connection to disconnect.

Deprecated:: Use event::~Connection to disconnect

References EventT< T >::Disconnect().

virtual unsigned int DOF ( ) const

pure virtual

Get the number of degrees of freedom for this joint.

Returns: The number of DOF for the joint.

Implemented in UniversalJoint< ODEJoint >, UniversalJoint< DARTJoint >, UniversalJoint< SimbodyJoint >, UniversalJoint< BulletJoint >, BallJoint< ODEJoint >, BallJoint< DARTJoint >, BallJoint< SimbodyJoint >, BallJoint< BulletJoint >, SliderJoint< ODEJoint >, SliderJoint< DARTJoint >, SliderJoint< SimbodyJoint >, SliderJoint< BulletJoint >, GearboxJoint< ODEJoint >, Hinge2Joint< ODEJoint >, Hinge2Joint< DARTJoint >, Hinge2Joint< SimbodyJoint >, Hinge2Joint< BulletJoint >, HingeJoint< ODEJoint >, HingeJoint< DARTJoint >, HingeJoint< SimbodyJoint >, HingeJoint< BulletJoint >, ScrewJoint< ODEJoint >, ScrewJoint< DARTJoint >, ScrewJoint< SimbodyJoint >, ScrewJoint< BulletJoint >, FixedJoint< ODEJoint >, FixedJoint< DARTJoint >, FixedJoint< SimbodyJoint >, and FixedJoint< BulletJoint >.

virtual void FillMsg ( msgs::Joint & _msg )

virtual

Fill a joint message.

Parameters

[out] _msg Message to fill with this joint's properties.

Reimplemented in GearboxJoint< ODEJoint >, ScrewJoint< ODEJoint >, ScrewJoint< DARTJoint >, ScrewJoint< SimbodyJoint >, and ScrewJoint< BulletJoint >.

Referenced by ScrewJoint< BulletJoint >::FillMsg(), and GearboxJoint< ODEJoint >::FillMsg().

bool FindAllConnectedLinks	(	const LinkPtr &	_originalParentLink,
		Link_V &	_connectedLinks
	)

protected

internal helper to find all links connected to the child link branching out from the children of the child link and any parent of the child link other than the parent link through this joint.

Parameters

[in]	_originalParentLink	parent link of this joint, this is used to check for loops connecting back to the parent link.
	in/out]	_connectedLinks list of aggregated links that contains all links connected to the child link of this joint. Empty if a loop is found that connects back to the parent link.

Returns: true if successful, false if a loop is found that connects back to the parent link.

virtual void Fini ( )

virtual

Finialize the object.

Reimplemented from Base.

Reimplemented in ODEJoint, and BulletJoint.

virtual math::Vector3 GetAnchor ( unsigned int _index ) const

virtual

Get the anchor point.

Parameters

[in] _index Index of the axis.

Returns: Anchor value for the axis.

Deprecated:: See function that returns ignition math.

math::Pose GetAnchorErrorPose ( ) const

Get pose offset between anchor pose on child and parent, expressed in the parent link frame.

This can be used to compute the bilateral constraint error.

Returns: Pose offset between anchor pose on child and parent, in parent link frame.

Deprecated:: See function that returns ignition math.

math::Angle GetAngle ( unsigned int _index ) const

Get the angle of rotation of an axis(index).

Parameters

[in] _index Index of the axis.

Returns: Angle of the axis.

Deprecated:: See Position(), which returns a double.

virtual unsigned int GetAngleCount ( ) const

virtual

Get the angle count.

Returns: The number of DOF for the joint.

Deprecated:: See DOF()

virtual math::Angle GetAngleImpl ( unsigned int _index ) const

protectedvirtual

Get the angle of an axis helper function.

Parameters

[in] _index Index of the axis.

Returns: Angle of the axis.

Deprecated:: See PositionImpl, which takes double.

math::Quaternion GetAxisFrame ( unsigned int _index ) const

Get orientation of reference frame for specified axis, relative to world frame.

The value of axisParentModelFrame is used to determine the appropriate frame.

Parameters

[in] _index joint axis index.

Returns: Orientation of axis frame relative to world frame.

Deprecated:: See function that returns ignition math.

math::Quaternion GetAxisFrameOffset ( unsigned int _index ) const

Get orientation of joint axis reference frame relative to joint frame.

This should always return identity unless flag use_parent_model_frame is true in sdf 1.5 or using sdf 1.4-, i.e. bug described in issue #494 is present. In addition, if use_parent_model_frame is true, and the parent link of the joint is world, the axis is defined in the world frame. The value of axisParentModelFrame is used to determine the appropriate frame internally.

Parameters

[in] _index joint axis index.

Returns: Orientation of axis frame relative to joint frame. If supplied _index is out of range, or use_parent_model_frame is not true, this function returns identity rotation quaternion.

Deprecated:: See function that returns ignition math.

BasePtr GetByName ( const std::string & _name )

inherited

Get by name.

Parameters

[in] _name Get a child (or self) object by name

Returns: A pointer to the object, NULL if not found

BasePtr GetChild ( unsigned int _i ) const

inherited

Get a child by index.

Parameters

[in] _i Index of the child to retreive.

Returns: A pointer to the object, NULL if the index is invalid.

BasePtr GetChild ( const std::string & _name )

inherited

Get a child by name.

Parameters

[in] _name Name of the child.

Returns: A pointer to the object, NULL if not found

LinkPtr GetChild ( ) const

Get the child link.

Returns: Pointer to the child link.

unsigned int GetChildCount ( ) const

inherited

Get the number of children.

Returns: The number of children.

double GetDamping ( unsigned int _index )

Returns the current joint damping coefficient.

Parameters

[in] _index Index of the axis to get, currently ignored, to be implemented.

Returns: Joint viscous damping coefficient for this joint.

virtual double GetEffortLimit ( unsigned int _index )

virtual

Get the effort limit on axis(index).

Parameters

[in] _index Index of axis, where 0=first axis and 1=second axis

Returns: Effort limit specified in SDF

virtual double GetForce ( unsigned int _index )

virtual

Todo:

: not yet implemented. Get external forces applied at this Joint. Note that the unit of force should be consistent with the rest of the simulation scales.

Parameters

[in] _index Index of the axis.

Returns: The force applied to an axis.

Reimplemented in ODEJoint, DARTJoint, BulletJoint, and SimbodyJoint.

virtual JointWrench GetForceTorque ( unsigned int _index )

pure virtual

get internal force and torque values at a joint.

The force and torque values are returned in a JointWrench data structure. Where JointWrench.body1Force contains the force applied by the parent Link on the Joint specified in the parent Link frame, and JointWrench.body2Force contains the force applied by the child Link on the Joint specified in the child Link frame. Note that this sign convention is opposite of the reaction forces of the Joint on the Links.

FIXME TODO: change name of this function to something like: GetNegatedForceTorqueInLinkFrame and make GetForceTorque call return non-negated reaction forces in perspective Link frames.

Note that for ODE you must set <provide_feedback>true<provide_feedback> in the joint sdf to use this.

Parameters

[in] _index Not used right now

Returns: The force and torque at the joint, see above for details on conventions.

Implemented in ODEJoint, DARTJoint, BulletJoint, and SimbodyJoint.

virtual math::Vector3 GetGlobalAxis ( unsigned int _index ) const

virtual

Get the axis of rotation in global cooridnate frame.

Parameters

[in] _index Index of the axis to get.

Returns: Axis value for the provided index.

Deprecated:: See GlobalAxis()

virtual math::Angle GetHighStop ( unsigned int _index )

virtual

Get the high stop of an axis(index).

This function is replaced by GetUpperLimit(unsigned int). If you are interested in getting the value of dParamHiStop*, use GetAttribute(hi_stop, _index)

Parameters

[in] _index Index of the axis.

Returns: Angle of the high stop value.

Deprecated:: See UpperLimit, which returns double.

uint32_t GetId ( ) const

inherited

Return the ID of this entity.

This id is unique.

Returns: Integer ID.

double GetInertiaRatio ( const unsigned int _index ) const

Computes moment of inertia (MOI) across a specified joint axis.

The ratio is given in the form of MOI_child / MOI_parent. If MOI_parent is zero, this funciton will return 0. The inertia ratio for each joint axis indicates the sensitivity of the joint to actuation torques.

Parameters

[in] _index axis number about which MOI ratio is computed.

Returns: ratio of child MOI to parent MOI.

double GetInertiaRatio ( const math::Vector3 & _axis ) const

Computes moment of inertia (MOI) across an arbitrary axis specified in the world frame.

The ratio is given in the form of MOI_child / MOI_parent. If MOI_parent is zero, this funciton will return 0. The moment of inertia ratio along constrained directions of a joint has an impact on the performance of Projected Gauss Seidel (PGS) iterative LCP methods.

Parameters

[in] _axis axis in world frame for which MOI ratio is computed.

Returns: ratio of child MOI to parent MOI.

Deprecated:: See function that takes ignition math.

math::Pose GetInitialAnchorPose ( ) const

Get initial Anchor Pose specified by model <joint><pose>...</pose></joint>

Returns: Joint::anchorPose, initial joint anchor pose.

Deprecated:: See function that returns ignition math.

virtual LinkPtr GetJointLink ( unsigned int _index ) const

pure virtual

Get the link to which the joint is attached according the _index.

Parameters

[in] _index Index of the link to retreive.

Returns: Pointer to the request link. NULL if the index was invalid.

Implemented in ODEJoint, BulletJoint, DARTJoint, and SimbodyJoint.

virtual math::Vector3 GetLinkForce ( unsigned int _index ) const

virtual

Get the forces applied to the center of mass of a physics::Link due to the existence of this Joint.

Note that the unit of force should be consistent with the rest of the simulation scales.

Parameters

[in] index The index of the link(0 or 1).

Returns: Force applied to the link.

Deprecated:: See function that returns ignition math.

virtual math::Vector3 GetLinkTorque ( unsigned int _index ) const

virtual

Get the torque applied to the center of mass of a physics::Link due to the existence of this Joint.

Note that the unit of torque should be consistent with the rest of the simulation scales.

Parameters

[in] index The index of the link(0 or 1)

Returns: Torque applied to the link.

Deprecated:: See function that returns ignition math.

math::Vector3 GetLocalAxis ( unsigned int _index ) const

Get the axis of rotation.

Parameters

[in] _index Index of the axis to get.

Returns: Axis value for the provided index.

Deprecated:: See LocalAxis()

math::Angle GetLowerLimit ( unsigned int _index ) const

: get the joint lower limit (replaces GetLowStop and GetHighStop)

Parameters

[in] _index Index of the axis.

Returns: Lower limit of the axis.

Deprecated:: See LowerLimit, which returns double.

virtual math::Angle GetLowStop ( unsigned int _index )

virtual

Get the low stop of an axis(index).

This function is replaced by GetLowerLimit(unsigned int). If you are interested in getting the value of dParamHiStop*, use GetAttribute(hi_stop, _index)

Parameters

[in] _index Index of the axis.

Returns: Angle of the low stop value.

Deprecated:: See LowerLimit, which returns double.

msgs::Joint::Type GetMsgType ( ) const

Get the joint type as msgs::Joint::Type.

Returns: Joint type.

std::string GetName ( ) const

inherited

Return the name of the entity.

Returns: Name of the entity.

virtual double GetParam	(	const std::string &	_key,
		unsigned int	_index
	)

virtual

Get a non-generic parameter for the joint.

See Also: SetParam(const std::string &, unsigned int, const boost::any)

Parameters

[in]	_key	String key.
[in]	_index	Index of the axis.

Reimplemented in ODEJoint, DARTJoint, BulletScrewJoint, BulletJoint, SimbodyScrewJoint, ODEScrewJoint, BulletUniversalJoint, SimbodyJoint, BulletHingeJoint, BulletSliderJoint, ODEUniversalJoint, and DARTScrewJoint.

LinkPtr GetParent ( ) const

Get the parent link.

Returns: Pointer to the parent link.

int GetParentId ( ) const

inherited

Return the ID of the parent.

Returns: Integer ID.

math::Pose GetParentWorldPose ( ) const

Get anchor pose on parent link relative to world frame.

When there is zero joint error, this should match the value returned by Joint::GetWorldPose() for the constrained degrees of freedom.

Returns: Anchor pose on parent link in world frame.

Deprecated:: See function that returns ignition math.

bool GetSaveable ( ) const

inherited

Get whether the object should be "saved", when the user selects to save the world to xml.

Returns: True if the object is saveable.

std::string GetScopedName ( bool _prependWorldName = false ) const

inherited

Return the name of this entity with the model scope model1::...::modelN::entityName.

Parameters

[in] _prependWorldName True to prended the returned string with the world name. The result will be world::model1::...::modelN::entityName.

Returns: The scoped name.

virtual const sdf::ElementPtr GetSDF ( )

virtualinherited

Get the SDF values for the object.

Returns: The SDF values for the object.

Reimplemented in Actor, and Model.

double GetSpringReferencePosition ( unsigned int _index ) const

Get joint spring reference position.

Parameters

[in] _index Index of the axis to get.

Returns: Joint spring reference position (in radians for angular joints).

double GetStiffness ( unsigned int _index )

Returns the current joint spring stiffness coefficient.

Parameters

[in] _index Index of the axis to get, currently ignored, to be implemented.

Returns: Joint spring stiffness coefficient for this joint. : rename to GetSpringStiffness()

double GetStopDissipation ( unsigned int _index ) const

Get joint stop dissipation.

Parameters

[in] _index joint axis index.

Returns: joint stop dissipation coefficient.

double GetStopStiffness ( unsigned int _index ) const

Get joint stop stiffness.

Parameters

[in] _index joint axis index.

Returns: joint stop stiffness coefficient.

unsigned int GetType ( ) const

inherited

Get the full type definition.

Returns: The full type definition.

math::Angle GetUpperLimit ( unsigned int _index ) const

: get the joint upper limit (replacee GetLowStop and GetHighStop)

Parameters

[in] _index Index of the axis.

Returns: Upper limit of the axis.

Deprecated:: See UpperLimit, which returns double.

virtual double GetVelocity ( unsigned int _index ) const

pure virtual

Get the rotation rate of an axis(index)

Parameters

[in] _index Index of the axis.

Returns: The rotaional velocity of the joint axis.

Implemented in BulletScrewJoint, DARTScrewJoint, SimbodyScrewJoint, ODEScrewJoint, ODEGearboxJoint, BulletSliderJoint, ODEHingeJoint, ODEHinge2Joint, ODEFixedJoint, ODESliderJoint, BulletBallJoint, BulletHinge2Joint, DARTFixedJoint, DARTHingeJoint, SimbodyBallJoint, DARTSliderJoint, ODEUniversalJoint, DARTHinge2Joint, SimbodyUniversalJoint, BulletUniversalJoint, DARTUniversalJoint, BulletHingeJoint, ODEBallJoint, SimbodyHinge2Joint, BulletFixedJoint, DARTBallJoint, SimbodyHingeJoint, SimbodySliderJoint, and SimbodyFixedJoint.

virtual double GetVelocityLimit ( unsigned int _index )

virtual

Get the velocity limit on axis(index).

Parameters

[in] _index Index of axis, where 0=first axis and 1=second axis

Returns: Velocity limit specified in SDF

const WorldPtr& GetWorld ( ) const

inherited

Get the World this object is in.

Returns: The World this object is part of.

double GetWorldEnergyPotentialSpring ( unsigned int _index ) const

Returns this joint's spring potential energy, based on the reference position of the spring.

If using metric system, the unit of energy will be Joules.

Returns: this joint's spring potential energy,

math::Pose GetWorldPose ( ) const

Get pose of joint frame relative to world frame.

Note that the joint frame is defined with a fixed offset from the child link frame.

Returns: Pose of joint frame relative to world frame.

Deprecated:: See function that returns ignition math.

virtual ignition::math::Vector3d GlobalAxis ( unsigned int _index ) const

pure virtual

Get the axis of rotation in global cooridnate frame.

Parameters

[in] _index Index of the axis to get.

Returns: Axis value for the provided index.

Implemented in BulletScrewJoint, BulletHinge2Joint, SimbodyScrewJoint, BulletBallJoint, BulletUniversalJoint, BulletHingeJoint, BulletSliderJoint, SimbodyBallJoint, BulletFixedJoint, SimbodyUniversalJoint, SimbodyHinge2Joint, ODEHinge2Joint, ODEGearboxJoint, ODEHingeJoint, SimbodyFixedJoint, SimbodyHingeJoint, DARTScrewJoint, ODESliderJoint, SimbodySliderJoint, ODEFixedJoint, ODEBallJoint, ODEUniversalJoint, DARTFixedJoint, DARTHinge2Joint, DARTHingeJoint, ODEScrewJoint, DARTUniversalJoint, DARTBallJoint, and DARTSliderJoint.

bool HasType ( const EntityType & _t ) const

inherited

Returns true if this object's type definition has the given type.

Parameters

[in] _t Type to check.

Returns: True if this object's type definition has the.

double InertiaRatio ( const ignition::math::Vector3d & _axis ) const

Computes moment of inertia (MOI) across an arbitrary axis specified in the world frame.

The ratio is given in the form of MOI_chidl / MOI_parent. If MOI_parent is zero, this funciton will return 0. The moment of inertia ratio along constrained directions of a joint has an impact on the performance of Projected Gauss Seidel (PGS) iterative LCP methods.

Parameters

[in] _axis axis in world frame for which MOI ratio is computed.

Returns: ratio of child MOI to parent MOI.

virtual void Init ( )

virtual

Initialize a joint.

Reimplemented from Base.

Reimplemented in BulletJoint, ScrewJoint< ODEJoint >, ScrewJoint< DARTJoint >, ScrewJoint< SimbodyJoint >, ScrewJoint< BulletJoint >, GearboxJoint< ODEJoint >, UniversalJoint< ODEJoint >, UniversalJoint< DARTJoint >, UniversalJoint< SimbodyJoint >, UniversalJoint< BulletJoint >, BallJoint< ODEJoint >, BallJoint< DARTJoint >, BallJoint< SimbodyJoint >, BallJoint< BulletJoint >, BulletScrewJoint, HingeJoint< ODEJoint >, HingeJoint< DARTJoint >, HingeJoint< SimbodyJoint >, HingeJoint< BulletJoint >, DARTScrewJoint, BulletBallJoint, FixedJoint< ODEJoint >, FixedJoint< DARTJoint >, FixedJoint< SimbodyJoint >, FixedJoint< BulletJoint >, BulletHinge2Joint, DARTJoint, BulletUniversalJoint, BulletFixedJoint, BulletHingeJoint, BulletSliderJoint, ODEGearboxJoint, DARTFixedJoint, DARTHinge2Joint, DARTHingeJoint, DARTUniversalJoint, DARTBallJoint, and DARTSliderJoint.

ignition::math::Pose3d InitialAnchorPose ( ) const

Get initial Anchor Pose specified by model <joint><pose>...</pose></joint>

Returns: Joint::anchorPose, initial joint anchor pose.

bool IsSelected ( ) const

inherited

True if the entity is selected by the user.

Returns: True if the entity is selected.

virtual ignition::math::Vector3d LinkForce ( const unsigned int _index ) const

pure virtual

Get the forces applied to the center of mass of a physics::Link due to the existence of this Joint.

Note that the unit of force should be consistent with the rest of the simulation scales.

Parameters

[in] index The index of the link(0 or 1).

Returns: Force applied to the link.

Implemented in ODEJoint, DARTJoint, BulletJoint, and SimbodyJoint.

virtual ignition::math::Vector3d LinkTorque ( const unsigned int _index ) const

pure virtual

Get the torque applied to the center of mass of a physics::Link due to the existence of this Joint.

Note that the unit of torque should be consistent with the rest of the simulation scales.

Parameters

[in] index The index of the link(0 or 1)

Returns: Torque applied to the link.

Implemented in ODEJoint, DARTJoint, BulletJoint, and SimbodyJoint.

void Load	(	LinkPtr	_parent,
		LinkPtr	_child,
		const math::Pose &	_pose
	)

Set pose, parent and child links of a physics::Joint.

Parameters

[in]	_parent	Parent link.
[in]	_child	Child link.
[in]	_pose	Pose containing Joint Anchor offset from child link.

Deprecated:: See function that takes ignition math.

void Load	(	LinkPtr	_parent,
		LinkPtr	_child,
		const ignition::math::Pose3d &	_pose
	)

Set pose, parent and child links of a physics::Joint.

Parameters

[in]	_parent	Parent link.
[in]	_child	Child link.
[in]	_pose	Pose containing Joint Anchor offset from child link.

virtual void Load ( sdf::ElementPtr _sdf )

virtual

Load physics::Joint from a SDF sdf::Element.

Parameters

[in] _sdf SDF values to load from.

Reimplemented from Base.

Reimplemented in SimbodySliderJoint, BallJoint< ODEJoint >, BallJoint< DARTJoint >, BallJoint< SimbodyJoint >, BallJoint< BulletJoint >, UniversalJoint< ODEJoint >, UniversalJoint< DARTJoint >, UniversalJoint< SimbodyJoint >, UniversalJoint< BulletJoint >, GearboxJoint< ODEJoint >, Hinge2Joint< ODEJoint >, Hinge2Joint< DARTJoint >, Hinge2Joint< SimbodyJoint >, Hinge2Joint< BulletJoint >, ODEJoint, BulletScrewJoint, HingeJoint< ODEJoint >, HingeJoint< DARTJoint >, HingeJoint< SimbodyJoint >, HingeJoint< BulletJoint >, BulletBallJoint, ScrewJoint< ODEJoint >, ScrewJoint< DARTJoint >, ScrewJoint< SimbodyJoint >, ScrewJoint< BulletJoint >, BulletHinge2Joint, DARTJoint, SliderJoint< ODEJoint >, SliderJoint< DARTJoint >, SliderJoint< SimbodyJoint >, SliderJoint< BulletJoint >, BulletJoint, ODEHinge2Joint, ODEHingeJoint, SimbodyFixedJoint, FixedJoint< ODEJoint >, FixedJoint< DARTJoint >, FixedJoint< SimbodyJoint >, FixedJoint< BulletJoint >, BulletUniversalJoint, ODESliderJoint, SimbodyUniversalJoint, BulletFixedJoint, BulletHingeJoint, BulletSliderJoint, ODEGearboxJoint, SimbodyHinge2Joint, SimbodyHingeJoint, SimbodyScrewJoint, ODEFixedJoint, SimbodyJoint, DARTFixedJoint, DARTHinge2Joint, DARTHingeJoint, DARTScrewJoint, DARTUniversalJoint, ODEScrewJoint, SimbodyBallJoint, DARTBallJoint, and DARTSliderJoint.

ignition::math::Vector3d LocalAxis ( const unsigned int _index ) const

Get the axis of rotation.

Parameters

[in] _index Index of the axis to get.

Returns: Axis value for the provided index.

virtual double LowerLimit ( unsigned int _index = 0 ) const

virtual

Get the joint's lower limit.

For rotational axes, the value is in radians, for prismatic axes it is in meters.

Parameters

[in] _index Index of the axis, defaults to 0.

Returns: Lower limit of the axis.

Reimplemented in SimbodyJoint, DARTJoint, DARTScrewJoint, BulletBallJoint, BulletHinge2Joint, SimbodyBallJoint, BulletUniversalJoint, BulletHingeJoint, DARTBallJoint, ODEBallJoint, BulletSliderJoint, and SimbodyScrewJoint.

bool operator== ( const Base & _ent ) const

inherited

Returns true if the entities are the same.

Checks only the name.

Parameters

[in] _ent Base object to compare with.

Returns: True if the entities are the same.

ignition::math::Pose3d ParentWorldPose ( ) const

Get anchor pose on parent link relative to world frame.

When there is zero joint error, this should match the value returned by Joint::WorldPose() for the constrained degrees of freedom.

Returns: Anchor pose on parent link in world frame.

virtual double Position ( const unsigned int _index = 0 ) const

finalvirtual

Get the position of an axis according to its index.

For rotational axes, the value is in radians. For prismatic axes, it is in meters.

For static models, it returns the static joint position.

It returns ignition::math::NAN_D in case the position can't be obtained. For instance, if the index is invalid, if the joint is fixed, etc.

Subclasses can't override this method. See PositionImpl instead.

Parameters

[in] _index Index of the axis, defaults to 0.

Returns: Current position of the axis.

See Also: PositionImpl

virtual double PositionImpl ( const unsigned int _index = 0 ) const

protectedpure virtual

Helper function to get the position of an axis.

Subclasses must override this.

Parameters

[in] _index Index of the axis, defaults to 0.

Returns: Position of the axis.

See Also: Position

Implemented in BulletScrewJoint, BulletHinge2Joint, SimbodyScrewJoint, DARTScrewJoint, BulletUniversalJoint, BulletHingeJoint, BulletSliderJoint, BulletBallJoint, ODEScrewJoint, BulletFixedJoint, SimbodyUniversalJoint, ODEGearboxJoint, SimbodyHinge2Joint, SimbodyBallJoint, SimbodyHingeJoint, ODEHinge2Joint, ODEHingeJoint, ODESliderJoint, ODEBallJoint, ODEFixedJoint, SimbodyFixedJoint, ODEUniversalJoint, DARTBallJoint, DARTFixedJoint, DARTHinge2Joint, DARTHingeJoint, SimbodySliderJoint, DARTUniversalJoint, and DARTSliderJoint.

void Print ( const std::string & _prefix )

inherited

Print this object to screen via gzmsg.

Parameters

[in] _prefix Usually a set of spaces.

virtual void RegisterIntrospectionItems ( )

protectedvirtual

Register items in the introspection service.

Reimplemented from Base.

virtual void RemoveChild ( unsigned int _id )

virtualinherited

Remove a child from this entity.

Parameters

[in] _id ID of the child to remove.

void RemoveChild ( const std::string & _name )

inherited

Remove a child by name.

Parameters

[in] _name Name of the child.

void RemoveChild ( physics::BasePtr _child )

inherited

Remove a child by pointer.

Parameters

[in] _child Pointer to the child.

void RemoveChildren ( )

inherited

Remove all children.

virtual void Reset ( )

virtual

Reset the joint.

Reimplemented from Base.

Reimplemented in ODEJoint, DARTJoint, BulletJoint, and SimbodyJoint.

virtual void Reset ( Base::EntityType _resetType )

virtualinherited

Calls recursive Reset on one of the Base::EntityType's.

Parameters

[in] _resetType The type of reset operation

virtual void SetAnchor	(	unsigned int	_index,
		const math::Vector3 &	_anchor
	)

virtual

Set the anchor point.

Parameters

[in]	_index	Index of the axis.
[in]	_anchor	Anchor value.

Deprecated:: See function that takes ignition math.

virtual void SetAnchor	(	const unsigned int	_index,
		const ignition::math::Vector3d &	_anchor
	)

pure virtual

Set the anchor point.

Parameters

[in]	_index	Index of the axis.
[in]	_anchor	Anchor value.

Implemented in DARTJoint, BulletJoint, BulletScrewJoint, SimbodyJoint, ODEGearboxJoint, ODEHingeJoint, ODESliderJoint, ODEFixedJoint, ODEHinge2Joint, DARTScrewJoint, ODEBallJoint, ODEUniversalJoint, and ODEScrewJoint.

virtual void SetAxis	(	unsigned int	_index,
		const math::Vector3 &	_axis
	)

virtual

Set the axis of rotation where axis is specified in local joint frame.

Parameters

[in]	_index	Index of the axis to set.
[in]	_axis	Vector in local joint frame of axis direction (must have length greater than zero).

Deprecated:: See function that takes ignition math.

virtual void SetAxis	(	const unsigned int	_index,
		const ignition::math::Vector3d &	_axis
	)

pure virtual

Set the axis of rotation where axis is specified in local joint frame.

Parameters

[in]	_index	Index of the axis to set.
[in]	_axis	Vector in local joint frame of axis direction (must have length greater than zero).

Implemented in ODEJoint, SimbodyJoint, BulletBallJoint, SimbodyBallJoint, BulletScrewJoint, DARTBallJoint, ODEBallJoint, ODEGearboxJoint, ODEHingeJoint, DARTScrewJoint, ODESliderJoint, BulletHinge2Joint, ODEFixedJoint, ODEUniversalJoint, DARTFixedJoint, DARTHinge2Joint, DARTHingeJoint, ODEScrewJoint, BulletUniversalJoint, DARTUniversalJoint, BulletHingeJoint, DARTSliderJoint, ODEHinge2Joint, SimbodyUniversalJoint, SimbodyHinge2Joint, BulletFixedJoint, BulletSliderJoint, SimbodyHingeJoint, SimbodyScrewJoint, and SimbodySliderJoint.

virtual void SetDamping	(	unsigned int	_index,
		double	_damping
	)

pure virtual

Set the joint damping.

Parameters

[in]	_index	Index of the axis to set, currently ignored, to be implemented.
[in]	_damping	Damping value for the axis.

Implemented in ODEJoint, DARTJoint, BulletJoint, SimbodyJoint, and BulletSliderJoint.

virtual void SetEffortLimit	(	unsigned int	_index,
		double	_effort
	)

virtual

Set the effort limit on a joint axis.

Parameters

[in]	_index	Index of the axis to set.
[in]	_effort	Effort limit for the axis.

virtual void SetForce	(	unsigned int	_index,
		double	_effort
	)

pure virtual

Set the force applied to this physics::Joint.

Note that the unit of force should be consistent with the rest of the simulation scales. Force is additive (multiple calls to SetForce to the same joint in the same time step will accumulate forces on that Joint). Forces are truncated by effortLimit before applied.

Parameters

[in]	_index	Index of the axis.
[in]	_effort	Force value.

Implemented in ODEJoint, DARTJoint, BulletJoint, and SimbodyJoint.

virtual bool SetHighStop	(	unsigned int	_index,
		const math::Angle &	_angle
	)

virtual

Set the high stop of an axis(index).

Parameters

[in]	_index	Index of the axis.
[in]	_angle	High stop angle.

Deprecated:: See SetUpperLimit, which takes double.

void SetLowerLimit	(	unsigned int	_index,
		math::Angle	_limit
	)

: set the joint lower limit (replaces SetLowStop and SetHighStop)

Parameters

[in]	_index	Index of the axis.
[in]	_limit	Lower limit of the axis.

Deprecated:: See SetLowerLimit which takes double.

virtual void SetLowerLimit	(	const unsigned int	_index,
		const double	_limit
	)

virtual

Set the joint's lower limit.

For rotational axes, the value is in radians. For prismatic axes, it is in meters.

It returns ignition::math::NAN_D in case the limit can't be obtained. For instance, if the index is invalid, if the joint is fixed, etc.

Parameters

[in]	_index	Index of the axis.
[in]	_limit	Lower limit of the axis.

Reimplemented in ODEJoint, SimbodyJoint, DARTJoint, SimbodyBallJoint, BulletScrewJoint, DARTBallJoint, ODEBallJoint, ODEUniversalJoint, BulletHinge2Joint, BulletBallJoint, BulletUniversalJoint, BulletHingeJoint, BulletFixedJoint, BulletSliderJoint, and SimbodyScrewJoint.

virtual bool SetLowStop	(	unsigned int	_index,
		const math::Angle &	_angle
	)

virtual

Set the low stop of an axis(index).

Parameters

[in]	_index	Index of the axis.
[in]	_angle	Low stop angle.

Deprecated:: See SetLowerLimit, which takes double.

void SetModel ( ModelPtr _model )

Set the model this joint belongs too.

Parameters

[in] _model Pointer to a model.

virtual void SetName ( const std::string & _name )

virtualinherited

Set the name of the entity.

Parameters

[in] _name New name.

Reimplemented in Entity.

virtual bool SetParam	(	const std::string &	_key,
		unsigned int	_index,
		const boost::any &	_value
	)

pure virtual

Set a non-generic parameter for the joint.

replaces SetAttribute(Attribute, int, double) List of parameters: "friction" Axis Coulomb joint friction coefficient. "hi_stop" Axis upper limit. "lo_stop" Axis lower limit.

Parameters

[in]	_key	String key.
[in]	_index	Index of the axis.
[in]	_value	Value of the attribute.

Implemented in ODEJoint, DARTJoint, BulletJoint, SimbodyScrewJoint, ODEScrewJoint, BulletUniversalJoint, SimbodyJoint, BulletHingeJoint, BulletSliderJoint, DARTScrewJoint, and ODEUniversalJoint.

void SetParent ( BasePtr _parent )

inherited

Set the parent.

Parameters

[in] _parent Parent object.

virtual bool SetPosition	(	unsigned int	_index,
		double	_position
	)

virtual

The child links of this joint are updated based on desired position.

And all the links connected to the child link of this joint except through the parent link of this joint moves with the child link.

Parameters

[in]	_index	Index of the joint axis (degree of freedom).
[in]	_position	Position to set the joint to. unspecified, pure kinematic teleportation.

Returns: returns true if operation succeeds, false if it fails.

Reimplemented in ODEJoint, and BulletJoint.

bool SetPositionMaximal	(	unsigned int	_index,
		double	_position
	)

protected

Helper function for maximal coordinate solver SetPosition.

The child links of this joint are updated based on position change. And all the links connected to the child link of this joint except through the parent link of this joint moves with the child link.

Parameters

[in]	_index	Index of the joint axis (degree of freedom).
[in]	_position	Position to set the joint to.

Returns: returns true if operation succeeds, false if it fails.

virtual void SetProvideFeedback ( bool _enable )

virtual

Set whether the joint should generate feedback.

Parameters

[in] _enable True to enable joint feedback.

Reimplemented in ODEJoint, and BulletJoint.

void SetSaveable ( bool _v )

inherited

Set whether the object should be "saved", when the user selects to save the world to xml.

Parameters

[in] _v Set to True if the object should be saved.

virtual bool SetSelected ( bool _show )

virtualinherited

Set whether this entity has been selected by the user through the gui.

Parameters

[in] _show True to set this entity as selected.

Reimplemented in Link.

void SetState ( const JointState & _state )

Set the joint state.

Parameters

[in] _state Joint state

virtual void SetStiffness	(	unsigned int	_index,
		const double	_stiffness
	)

pure virtual

Set the joint spring stiffness.

Parameters

[in]	_index	Index of the axis to set, currently ignored, to be implemented.
[in]	_stiffness	Spring stiffness value for the axis. : rename to SetSpringStiffness()

Implemented in ODEJoint, DARTJoint, BulletJoint, and SimbodyJoint.

virtual void SetStiffnessDamping	(	unsigned int	_index,
		double	_stiffness,
		double	_damping,
		double	_reference = `0`
	)

pure virtual

Set the joint spring stiffness.

Parameters

[in]	_index	Index of the axis to set, currently ignored, to be implemented.
[in]	_stiffness	Stiffness value for the axis.
[in]	_reference	Spring zero load reference position. : rename to SetSpringStiffnessDamping()

Implemented in ODEJoint, DARTJoint, BulletJoint, and SimbodyJoint.

void SetStopDissipation	(	unsigned int	_index,
		double	_dissipation
	)

Set joint stop dissipation.

Parameters

[in]	_index	joint axis index.
[in]	_dissipation	joint stop dissipation coefficient.

void SetStopStiffness	(	unsigned int	_index,
		double	_stiffness
	)

Set joint stop stiffness.

Parameters

[in]	_index	joint axis index.
[in]	_stiffness	joint stop stiffness coefficient.

void SetUpperLimit	(	unsigned int	_index,
		math::Angle	_limit
	)

: set the joint upper limit (replacee GetLowStop and GetHighStop)

Parameters

[in]	_index	Index of the axis.
[in]	_limit	Upper limit of the axis.

Deprecated:: See SetUpperLimit which takes double.

virtual void SetUpperLimit	(	const unsigned int	_index,
		const double	_limit
	)

virtual

Set the joint's upper limit.

For rotational axes, the value is in radians, for prismatic axes it is in meters.

Parameters

[in]	_index	Index of the axis, defaults to 0.
[in]	_limit	Lower limit of the axis.

Reimplemented in ODEJoint, SimbodyJoint, DARTJoint, SimbodyBallJoint, BulletScrewJoint, DARTBallJoint, ODEBallJoint, ODEUniversalJoint, BulletHinge2Joint, BulletBallJoint, BulletUniversalJoint, BulletHingeJoint, BulletFixedJoint, BulletSliderJoint, and SimbodyScrewJoint.

virtual void SetVelocity	(	unsigned int	_index,
		double	_vel
	)

pure virtual

Set the velocity of an axis(index).

In ODE and Bullet, the SetVelocityMaximal function is used to set the velocity of the child link relative to the parent. In Simbody and DART, this function updates the velocity state, which has a recursive effect on the rest of the chain.

Parameters

[in]	_index	Index of the axis.
[in]	_vel	Velocity.

Implemented in BulletScrewJoint, DARTScrewJoint, SimbodyScrewJoint, ODEScrewJoint, BulletSliderJoint, ODEGearboxJoint, ODEHinge2Joint, ODESliderJoint, BulletHinge2Joint, ODEHingeJoint, ODEUniversalJoint, DARTHinge2Joint, DARTUniversalJoint, ODEFixedJoint, BulletBallJoint, DARTFixedJoint, DARTHingeJoint, SimbodyBallJoint, SimbodyHinge2Joint, DARTSliderJoint, SimbodyUniversalJoint, BulletUniversalJoint, BulletHingeJoint, ODEBallJoint, BulletFixedJoint, DARTBallJoint, SimbodyFixedJoint, SimbodyHingeJoint, and SimbodySliderJoint.

virtual void SetVelocityLimit	(	unsigned int	_index,
		double	_velocity
	)

virtual

Set the velocity limit on a joint axis.

Parameters

[in]	_index	Index of the axis to set.
[in]	_velocity	Velocity limit for the axis.

bool SetVelocityMaximal	(	unsigned int	_index,
		double	_velocity
	)

protected

Helper function for maximal coordinate solver SetVelocity.

The velocity of the child link of this joint is updated relative to the current parent velocity. It currently does not act recursively.

Parameters

[in]	_index	Index of the joint axis (degree of freedom).
[in]	_velocity	Velocity to set at this joint.

Returns: returns true if operation succeeds, false if it fails.

void SetWorld ( const WorldPtr & _newWorld )

inherited

Set the world this object belongs to.

This will also set the world for all children.

Parameters

[in] _newWorld The new World this object is part of.

std::string TypeStr ( ) const

inherited

Get the string name for the entity type.

Returns: The string name for this entity.

virtual void UnregisterIntrospectionItems ( )

protectedvirtualinherited

Unregister items in the introspection service.

void Update ( )

virtual

Update the joint.

Reimplemented from Base.

virtual void UpdateParameters ( sdf::ElementPtr _sdf )

virtual

Update the parameters using new sdf values.

Parameters

[in] _sdf SDF values to update from.

Reimplemented from Base.

virtual double UpperLimit ( const unsigned int _index = 0 ) const

virtual

Get the joint's upper limit.

For rotational axes, the value is in radians. For prismatic axes, it is in meters.

It returns ignition::math::NAN_D in case the limit can't be obtained. For instance, if the index is invalid, if the joint is fixed, etc.

Parameters

[in] _index Index of the axis, defaults to 0.

Returns: Lower limit of the axis.

Reimplemented in SimbodyJoint, DARTJoint, DARTScrewJoint, BulletBallJoint, BulletHinge2Joint, SimbodyBallJoint, BulletUniversalJoint, BulletHingeJoint, DARTBallJoint, ODEBallJoint, BulletSliderJoint, and SimbodyScrewJoint.

common::URI URI ( ) const

inherited

Return the common::URI of this entity.

The URI includes the world where the entity is contained and all the hierarchy of sub-entities that can compose this entity. E.g.: A link entity contains the name of the link and the model where the link is contained.

Returns: The URI of this entity.

ignition::math::Pose3d WorldPose ( ) const

Get pose of joint frame relative to world frame.

Note that the joint frame is defined with a fixed offset from the child link frame.

Returns: Pose of joint frame relative to world frame.

Member Data Documentation

LinkPtr anchorLink

protected

Anchor link.

ignition::math::Vector3d anchorPos

protected

Anchor pose.

This is the xyz position of the joint frame specified in the world frame.

ignition::math::Pose3d anchorPose

protected

Anchor pose specified in SDF <joint><pose> tag.

AnchorPose is the transform from child link frame to joint frame specified in the child link frame. AnchorPos is more relevant in normal usage, but sometimes, we do need this (e.g. GetForceTorque and joint visualization).

gazebo::event::ConnectionPtr applyDamping

protected

apply damping for adding viscous damping forces on updates

bool axisParentModelFrame[2]

protected

Flags that are set to true if an axis value is expressed in the parent model frame.

Otherwise use the joint frame. See issue #494.

LinkPtr childLink

protected

The first link this joint connects to.

Base_V children

protectedinherited

Children of this entity.

double dissipationCoefficient[2]

protected

joint viscous damping coefficient

double effortLimit[2]

protected

Store Joint effort limit as specified in SDF.

std::vector<common::URI> introspectionItems

protectedinherited

All the introspection items regsitered for this.

double lowerLimit[2]

protected

Store Joint position lower limit as specified in SDF.

ModelPtr model

protected

Pointer to the parent model.

BasePtr parent

protectedinherited

Parent of this entity.

ignition::math::Pose3d parentAnchorPose

protected

Anchor pose relative to parent link frame.

LinkPtr parentLink

protected

The second link this joint connects to.

bool provideFeedback

protected

Provide Feedback data for contact forces.

sdf::ElementPtr sdf

protectedinherited

The SDF values for this object.

double springReferencePosition[2]

protected

joint spring reference (zero load) position

double stiffnessCoefficient[2]

protected

joint stiffnessCoefficient

double upperLimit[2]

protected

Store Joint position upper limit as specified in SDF.

double velocityLimit[2]

protected

Store Joint velocity limit as specified in SDF.

WorldPtr world

protectedinherited

Pointer to the world.

JointWrench wrench

protected

Cache Joint force torque values in case physics engine clears them at the end of update step.

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

Joint.hh

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation