gazebo::physics::Joint Class Reference

Base class for all joints. More...

#include <physics/physics.hh>

Inheritance diagram for gazebo::physics::Joint:

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...
Public Types inherited from gazebo::physics::Base
enum	EntityType {   BASE = 0x00000000, ENTITY = 0x00000001, MODEL = 0x00000002, LINK = 0x00000004,   COLLISION = 0x00000008, ACTOR = 0x00000016, LIGHT = 0x00000010, VISUAL = 0x00000020,   JOINT = 0x00000040, BALL_JOINT = 0x00000080, HINGE2_JOINT = 0x00000100, HINGE_JOINT = 0x00000200,   SLIDER_JOINT = 0x00000400, SCREW_JOINT = 0x00000800, UNIVERSAL_JOINT = 0x00001000, SHAPE = 0x00002000,   BOX_SHAPE = 0x00004000, CYLINDER_SHAPE = 0x00008000, HEIGHTMAP_SHAPE = 0x00010000, MAP_SHAPE = 0x00020000,   MULTIRAY_SHAPE = 0x00040000, RAY_SHAPE = 0x00080000, PLANE_SHAPE = 0x00100000, SPHERE_SHAPE = 0x00200000,   TRIMESH_SHAPE = 0x00400000 }
	Unique identifiers for all entity types. More...

Public Member Functions
	Joint (BasePtr _parent)
	Constructor.
virtual	~Joint ()
	Destructor.
virtual bool	AreConnected (LinkPtr _one, LinkPtr _two) const =0
	Determines of the two bodies are connected by a joint.
virtual void	Attach (LinkPtr _parent, LinkPtr _child)
	Attach the two bodies with this joint.
template<typename T >
event::ConnectionPtr	ConnectJointUpdate (T _subscriber)
	Connect a boost::slot the the joint update signal.
virtual void	Detach ()
	Detach this joint from all links.
void	DisconnectJointUpdate (event::ConnectionPtr &_conn)
	Disconnect a boost::slot the the joint update signal.
void	FillJointMsg (msgs::Joint &_msg) GAZEBO_DEPRECATED
	DEPRECATED.
void	FillMsg (msgs::Joint &_msg)
	Fill a joint message.
virtual math::Vector3	GetAnchor (int _index) const =0
	Get the anchor point.
math::Angle	GetAngle (int _index) const
	Get the angle of rotation of an axis(index)
virtual unsigned int	GetAngleCount () const =0
	Get the angle count.
LinkPtr	GetChild () const
	Get the child link.
virtual double	GetForce (int _index)
virtual math::Vector3	GetGlobalAxis (int _index) const =0
	Get the axis of rotation in global cooridnate frame.
virtual math::Angle	GetHighStop (int _index)=0
	Get the high stop of an axis(index).
virtual LinkPtr	GetJointLink (int _index) const =0
	Get the link to which the joint is attached according the _index.
virtual math::Vector3	GetLinkForce (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.
virtual math::Vector3	GetLinkTorque (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.
math::Vector3	GetLocalAxis (int _index) const
	Get the axis of rotation.
virtual math::Angle	GetLowStop (int _index)=0
	Get the low stop of an axis(index).
virtual double	GetMaxForce (int _index)=0
	Get the max allowed force of an axis(index).
LinkPtr	GetParent () const
	Get the parent link.
virtual double	GetVelocity (int _index) const =0
	Get the rotation rate of an axis(index)
virtual void	Init ()
	Initialize a joint.
void	Load (LinkPtr _parent, LinkPtr _child, const math::Pose &_pose)
	Set pose, parent and child links of a physics::Joint.
virtual void	Load (sdf::ElementPtr _sdf)
	Load physics::Joint from a SDF sdf::Element.
virtual void	Reset ()
	Reset the joint.
virtual void	SetAnchor (int _index, const math::Vector3 &_anchor)=0
	Set the anchor point.
void	SetAngle (int _index, math::Angle _angle)
	If the Joint is static, Gazebo stores the state of this Joint as a scalar inside the Joint class, so this call will NOT move the joint dynamically for a static Model.
virtual void	SetAttribute (Attribute _attr, int _index, double _value) GAZEBO_DEPRECATED=0
	Set a parameter for the joint.
virtual void	SetAttribute (const std::string &_key, int _index, const boost::any &_value)=0
	Set a non-generic parameter for the joint.
virtual void	SetAxis (int _index, const math::Vector3 &_axis)=0
	Set the axis of rotation.
virtual void	SetDamping (int _index, double _damping)=0
	Set the joint damping.
virtual void	SetForce (int _index, double _force)
	Set the force applied to this physics::Joint.
virtual void	SetHighStop (int _index, const math::Angle &_angle)=0
	Set the high stop of an axis(index).
virtual void	SetLowStop (int _index, const math::Angle &_angle)=0
	Set the low stop of an axis(index).
virtual void	SetMaxForce (int _index, double _force)=0
	Set the max allowed force of an axis(index).
void	SetModel (ModelPtr _model)
	Set the model this joint belongs too.
void	SetState (const JointState &_state)
	Set the joint state.
virtual void	SetVelocity (int _index, double _vel)=0
	Set the velocity of an axis(index).
void	Update ()
	Update the joint.
virtual void	UpdateParameters (sdf::ElementPtr _sdf)
	Update the parameters using new sdf values.
Public Member Functions inherited from gazebo::physics::Base
	Base (BasePtr _parent)
	Constructor.
virtual	~Base ()
	Destructor.
void	AddChild (BasePtr _child)
	Add a child to this entity.
void	AddType (EntityType _type)
	Add a type specifier.
virtual void	Fini ()
	Finialize the object.
BasePtr	GetById (unsigned int _id) const
	Get a child or self by id.
BasePtr	GetByName (const std::string &_name)
	Get by name.
BasePtr	GetChild (unsigned int _i) const
	Get a child by index.
BasePtr	GetChild (const std::string &_name)
	Get a child by name.
unsigned int	GetChildCount () const
	Get the number of children.
unsigned int	GetId () const
	Return the ID of this entity.
std::string	GetName () const
	Return the name of the entity.
BasePtr	GetParent () const
	Get the parent.
int	GetParentId () const
	Return the ID of the parent.
bool	GetSaveable () const
	Get whether the object should be "saved", when the user selects to save the world to xml.
std::string	GetScopedName () const
	Return the name of this entity with the model scope world::model1::...::modelN::entityName.
virtual const sdf::ElementPtr	GetSDF ()
	Get the SDF values for the object.
unsigned int	GetType () const
	Get the full type definition.
const WorldPtr &	GetWorld () const
	Get the World this object is in.
bool	HasType (const EntityType &_t) const
	Returns true if this object's type definition has the given type.
bool	IsSelected () const
	True if the entity is selected by the user.
bool	operator== (const Base &_ent) const
	Returns true if the entities are the same.
void	Print (const std::string &_prefix)
	Print this object to screen via gzmsg.
virtual void	RemoveChild (unsigned int _id)
	Remove a child from this entity.
void	RemoveChild (const std::string &_name)
	Remove a child by name.
void	RemoveChildren ()
	Remove all children.
virtual void	Reset (Base::EntityType _resetType)
	Calls recursive Reset on one of the Base::EntityType's.
virtual void	SetName (const std::string &_name)
	Set the name of the entity.
void	SetParent (BasePtr _parent)
	Set the parent.
void	SetSaveable (bool _v)
	Set whether the object should be "saved", when the user selects to save the world to xml.
virtual bool	SetSelected (bool _show)
	Set whether this entity has been selected by the user through the gui.
void	SetWorld (const WorldPtr &_newWorld)
	Set the world this object belongs to.

Protected Member Functions
virtual math::Angle	GetAngleImpl (int _index) const =0
	Get the angle of an axis helper function.

Protected Attributes
LinkPtr	anchorLink
	Anchor link.
math::Vector3	anchorPos
	Anchor pose.
LinkPtr	childLink
	The first link this joint connects to.
double	damping_coefficient
	joint damping_coefficient
ModelPtr	model
	Pointer to the parent model.
LinkPtr	parentLink
	The second link this joint connects to.
Protected Attributes inherited from gazebo::physics::Base
Base_V	children
	Children of this entity.
Base_V::iterator	childrenEnd
	End of the children vector.
BasePtr	parent
	Parent of this entity.
sdf::ElementPtr	sdf
	The SDF values for this object.
WorldPtr	world
	Pointer to the world.

Detailed Description

Base class for all joints.

Member Enumeration Documentation

enum gazebo::physics::Joint::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	High stop angle.
LO_STOP	Low stop angle.

Constructor & Destructor Documentation

gazebo::physics::Joint::Joint ( BasePtr  _parent )

explicit

Constructor.

Parameters

[in]

Joint

parent

virtual gazebo::physics::Joint::~Joint ( )

virtual

Destructor.

Member Function Documentation

virtual bool gazebo::physics::Joint::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.

virtual void gazebo::physics::Joint::Attach ( LinkPtr  _parent, LinkPtr  _child  )

virtual

Attach the two bodies with this joint.

Parameters

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

template<typename T >

event::ConnectionPtr gazebo::physics::Joint::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 gazebo::event::EventT< T >::Connect().

virtual void gazebo::physics::Joint::Detach ( )

virtual

Detach this joint from all links.

void gazebo::physics::Joint::DisconnectJointUpdate ( event::ConnectionPtr &  _conn )

inline

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

Parameters

[in]

_conn

Connection to disconnect.

References gazebo::event::EventT< T >::Disconnect().

void gazebo::physics::Joint::FillJointMsg

(

msgs::Joint &

_msg

)

DEPRECATED.

Parameters

[out]

_msg

Message to fill with joint's properties

See Also

Joint::FillMsg

void gazebo::physics::Joint::FillMsg

(

msgs::Joint &

_msg

)

Fill a joint message.

Parameters

[out]

_msg

Message to fill with this joint's properties.

virtual math::Vector3 gazebo::physics::Joint::GetAnchor ( int  _index ) const

pure virtual

Get the anchor point.

Parameters

[in]

_index

Index of the axis.

Returns

Anchor value for the axis.

math::Angle gazebo::physics::Joint::GetAngle

(

int

_index

)

const

Get the angle of rotation of an axis(index)

Parameters

[in]

_index

Index of the axis.

Returns

Angle of the axis.

virtual unsigned int gazebo::physics::Joint::GetAngleCount ( ) const

pure virtual

Get the angle count.

Returns

The number of DOF for the joint.

virtual math::Angle gazebo::physics::Joint::GetAngleImpl ( int  _index ) const

protectedpure virtual

Get the angle of an axis helper function.

Parameters

[in]

_index

Index of the axis.

Returns

Angle of the axis.

LinkPtr gazebo::physics::Joint::GetChild

(

)

const

Get the child link.

Returns

Pointer to the child link.

virtual double gazebo::physics::Joint::GetForce ( int  _index )

virtual

Todo:

: not yet implemented. Get the internal forces at a this Joint. Note that the unit of force should be consistent with the rest of the simulation scales. E.g. if you are using metric units, the unit for force is Newtons. If using imperial units (sorry), then unit of force is lb-force not (lb-mass), etc.

Parameters

[in]

_index

Index of the axis.

Returns

The force applied to an axis.

virtual math::Vector3 gazebo::physics::Joint::GetGlobalAxis ( 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.

virtual math::Angle gazebo::physics::Joint::GetHighStop ( int  _index )

pure virtual

Get the high stop of an axis(index).

Parameters

[in]

_index

Index of the axis.

Returns

Angle of the high stop value.

virtual LinkPtr gazebo::physics::Joint::GetJointLink ( 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.

virtual math::Vector3 gazebo::physics::Joint::GetLinkForce ( 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. E.g. if you are using metric units, the unit for force is Newtons. If using imperial units (sorry), then unit of force is lb-force not (lb-mass), etc.

Parameters

[in]

index

The index of the link(0 or 1).

Returns

Force applied to the link.

virtual math::Vector3 gazebo::physics::Joint::GetLinkTorque ( 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. E.g. if you are using metric units, the unit for force is Newtons-Meters. If using imperial units (sorry), then unit of force is lb-force-inches not (lb-mass-inches), etc.

Parameters

[in]

index

The index of the link(0 or 1)

Returns

Torque applied to the link.

math::Vector3 gazebo::physics::Joint::GetLocalAxis

(

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 math::Angle gazebo::physics::Joint::GetLowStop ( int  _index )

pure virtual

Get the low stop of an axis(index).

Parameters

[in]

_index

Index of the axis.

Returns

Angle of the low stop value.

virtual double gazebo::physics::Joint::GetMaxForce ( int  _index )

pure virtual

Get the max allowed force of an axis(index).

Note that the unit of force should be consistent with the rest of the simulation scales. E.g. if you are using metric units, the unit for force is Newtons. If using imperial units (sorry), then unit of force is lb-force not (lb-mass), etc.

Parameters

[in]

_index

Index of the axis.

Returns

The maximum force.

LinkPtr gazebo::physics::Joint::GetParent

(

)

const

Get the parent link.

Returns

Pointer to the parent link.

virtual double gazebo::physics::Joint::GetVelocity ( 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.

virtual void gazebo::physics::Joint::Init ( )

virtual

Initialize a joint.

Reimplemented from gazebo::physics::Base.

void gazebo::physics::Joint::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 of the link.

virtual void gazebo::physics::Joint::Load ( sdf::ElementPtr  _sdf )

virtual

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

Parameters

[in]

_sdf

SDF values to load from.

Reimplemented from gazebo::physics::Base.

virtual void gazebo::physics::Joint::Reset ( )

virtual

Reset the joint.

Reimplemented from gazebo::physics::Base.

virtual void gazebo::physics::Joint::SetAnchor ( int  _index, const math::Vector3 &  _anchor  )

pure virtual

Set the anchor point.

Parameters

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

void gazebo::physics::Joint::SetAngle	(	int	_index,
		math::Angle	_angle
	)

If the Joint is static, Gazebo stores the state of this Joint as a scalar inside the Joint class, so this call will NOT move the joint dynamically for a static Model.

But if this Model is not static, then it is updated dynamically, all the conencted children Link's are moved as a result of the Joint angle setting. Dynamic Joint angle update is accomplished by calling JointController::SetJointPosition.

Parameters

[in]	_index	Index of the axis.
[in]	_angle	Angle to set the joint to.

virtual void gazebo::physics::Joint::SetAttribute ( Attribute  _attr, int  _index, double  _value  )

pure virtual

Set a parameter for the joint.

Parameters

[in]	_attr	Attribute to set.
[in]	_index	Index of the axis.
[in]	_value	Value of the attribute.

virtual void gazebo::physics::Joint::SetAttribute ( const std::string &  _key, int  _index, const boost::any &  _value  )

pure virtual

Set a non-generic parameter for the joint.

replaces SetAttribute(Attribute, int, double)

Parameters

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

virtual void gazebo::physics::Joint::SetAxis ( int  _index, const math::Vector3 &  _axis  )

pure virtual

Set the axis of rotation.

Parameters

[in]	_index	Index of the axis to set.
[in]	_axis	Axis value.

virtual void gazebo::physics::Joint::SetDamping ( int  _index, double  _damping  )

pure virtual

Set the joint damping.

Parameters

[in]	_index	Index of the axis to set.
[in]	_damping	Damping value for the axis.

virtual void gazebo::physics::Joint::SetForce ( int  _index, double  _force  )

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. E.g. if you are using metric units, the unit for force is Newtons. If using imperial units (sorry), then unit of force is lb-force not (lb-mass), etc.

Parameters

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

virtual void gazebo::physics::Joint::SetHighStop ( int  _index, const math::Angle &  _angle  )

pure virtual

Set the high stop of an axis(index).

Parameters

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

virtual void gazebo::physics::Joint::SetLowStop ( int  _index, const math::Angle &  _angle  )

pure virtual

Set the low stop of an axis(index).

Parameters

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

virtual void gazebo::physics::Joint::SetMaxForce ( int  _index, double  _force  )

pure virtual

Set the max allowed force of an axis(index).

Note that the unit of force should be consistent with the rest of the simulation scales. E.g. if you are using metric units, the unit for force is Newtons. If using imperial units (sorry), then unit of force is lb-force not (lb-mass), etc.

Parameters

[in]	_index	Index of the axis.
[in]	_force	Maximum force that can be applied to the axis.

void gazebo::physics::Joint::SetModel

(

ModelPtr

_model

)

Set the model this joint belongs too.

Parameters

[in]

_model

Pointer to a model.

void gazebo::physics::Joint::SetState

(

const JointState &

_state

)

Set the joint state.

Parameters

[in]

_state

Joint state

virtual void gazebo::physics::Joint::SetVelocity ( int  _index, double  _vel  )

pure virtual

Set the velocity of an axis(index).

Parameters

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

void gazebo::physics::Joint::Update ( )

virtual

Update the joint.

Reimplemented from gazebo::physics::Base.

virtual void gazebo::physics::Joint::UpdateParameters ( sdf::ElementPtr  _sdf )

virtual

Update the parameters using new sdf values.

Parameters

[in]

_sdf

SDF values to update from.

Reimplemented from gazebo::physics::Base.

Member Data Documentation

LinkPtr gazebo::physics::Joint::anchorLink

protected

Anchor link.

math::Vector3 gazebo::physics::Joint::anchorPos

protected

Anchor pose.

LinkPtr gazebo::physics::Joint::childLink

protected

The first link this joint connects to.

double gazebo::physics::Joint::damping_coefficient

protected

joint damping_coefficient

ModelPtr gazebo::physics::Joint::model

protected

Pointer to the parent model.

LinkPtr gazebo::physics::Joint::parentLink

protected

The second link this joint connects to.

---

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

• Joint.hh