Base class for all joints. More...

#include <SimbodyJoint.hh>

Inheritance diagram for gazebo::physics::SimbodyJoint:

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

virtual	~SimbodyJoint ()
	Destructor. More...

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

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

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

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

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

virtual double	GetForce (unsigned int _index)

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

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

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

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

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

virtual void	RestoreSimbodyState (SimTK::State &_state)

virtual void	SaveSimbodyState (const SimTK::State &_state)

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

virtual void	SetAttribute (Attribute, int _index, double _value)
	Set a parameter for the joint. More...

virtual void	SetAttribute (const std::string &_key, int _index, const boost::any &_value)
	Set a non-generic parameter for the joint. More...

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

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

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

Public Member Functions inherited from gazebo::physics::Joint
	Joint (BasePtr _parent)
	Constructor. More...

virtual	~Joint ()
	Destructor. More...

virtual void	ApplyDamping ()
	Callback to apply damping force to joint. More...

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

double	CheckAndTruncateForce (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...

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

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

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

virtual unsigned int	GetAngleCount () const =0
	Get the angle count. More...

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

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

double	GetDampingCoefficient () const
	Get damping coefficient of this joint. More...

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

virtual math::Vector3	GetGlobalAxis (int _index) const =0
	Get the axis of rotation in global cooridnate frame. More...

virtual math::Angle	GetHighStop (int _index)=0
	Get the high stop of an axis(index). More...

double	GetInertiaRatio (unsigned int _index) const
	Accessor to inertia ratio across this joint. More...

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

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

virtual math::Angle	GetLowStop (int _index)=0
	Get the low stop of an axis(index). More...

virtual double	GetMaxForce (int _index)=0
	Get the max allowed force of an axis(index). More...

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

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

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

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

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

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

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. More...

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

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

virtual void	SetMaxForce (int _index, double _force)=0
	Set the max allowed force of an axis(index). More...

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

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

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

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

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

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

Public Member Functions inherited from gazebo::physics::Base
	Base (BasePtr _parent)
	Constructor. More...

virtual	~Base ()
	Destructor. More...

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

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

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

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

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

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

BasePtr	GetParent () const
	Get the parent. More...

int	GetParentId () const
	Return the ID of the parent. 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 () const
	Return the name of this entity with the model scope world::model1::...::modelN::entityName. More...

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

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

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

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

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

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

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

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

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

Public Attributes
SimTK::Constraint	constraint
	: isValid() if we used a constraint to model this joint. More...

SimTK::Force::MobilityLinearDamper	damper
	: for enforcing joint damping forces. More...

SimTK::Transform	defxAB
	default mobilizer pose More...

bool	isReversed
	: if mobilizer, did it reverse parent&child? Set when we build the Simbody model. More...

SimTK::Force::MobilityLinearStop	limitForce
	: for enforcing joint stops Set when we build the Simbody model. More...

SimTK::MobilizedBody	mobod
	Use isValid() if we used a mobilizer Set when we build the Simbody model. More...

bool	mustBreakLoopHere
	Force Simbody to break a loop by using a weld constraint. More...

bool	physicsInitialized

SimTK::Transform	xCB
	child body frame to mobilizer frame More...

SimTK::Transform	xPA
	Normally A=F, B=M. More...

Protected Member Functions
virtual void	SetForceImpl (int _index, double _force)=0
	Set the force applied to this physics::Joint. More...

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

Protected Member Functions inherited from gazebo::physics::Base
void	ComputeScopedName ()
	Compute the scoped name of this object based on its parents. More...

Protected Attributes
SimbodyPhysicsPtr	simbodyPhysics
	keep a pointer to the simbody physics engine for convenience More...

SimTK::MultibodySystem *	world
	Simbody Multibody System. More...

Protected Attributes inherited from gazebo::physics::Joint
LinkPtr	anchorLink
	Anchor link. More...

math::Vector3	anchorPos
	Anchor pose. More...

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

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

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

double	dampingCoefficient
	joint dampingCoefficient More...

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

double	inertiaRatio [2]
	Store Joint inertia ratio. More...

math::Angle	lowerLimit [2]
	Store Joint position lower limit as specified in SDF. More...

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

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

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

math::Angle	upperLimit [2]
	Store Joint position upper limit as specified in SDF. More...

bool	useCFMDamping
	option to use CFM damping More...

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

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

Protected Attributes inherited from gazebo::physics::Base
Base_V	children
	Children of this entity. More...

Base_V::iterator	childrenEnd
	End of the children vector. More...

BasePtr	parent
	Parent of this entity. More...

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

WorldPtr	world
	Pointer to the world. More...

Additional Inherited Members
Public Types inherited from gazebo::physics::Joint
enum	Attribute { FUDGE_FACTOR, SUSPENSION_ERP, SUSPENSION_CFM, STOP_ERP, STOP_CFM, ERP, CFM, FMAX, VEL, HI_STOP, LO_STOP }
	Joint attribute types. More...

Detailed Description

Base class for all joints.

Constructor & Destructor Documentation

gazebo::physics::SimbodyJoint::SimbodyJoint ( BasePtr _parent )

Constructor.

virtual gazebo::physics::SimbodyJoint::~SimbodyJoint ( )

virtual

Destructor.

Member Function Documentation

virtual bool gazebo::physics::SimbodyJoint::AreConnected	(	LinkPtr	_one,
		LinkPtr	_two
	)		const

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.

Implements gazebo::physics::Joint.

virtual void gazebo::physics::SimbodyJoint::CacheForceTorque ( )

virtual

Cache Joint Force Torque Values if necessary for physics engine.

Reimplemented from gazebo::physics::Joint.

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

virtual

Detach this joint from all links.

Reimplemented from gazebo::physics::Joint.

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

virtual

Get the anchor point.

Parameters

[in] _index Index of the axis.

Returns: Anchor value for the axis.

Implements gazebo::physics::Joint.

Reimplemented in gazebo::physics::ScrewJoint< SimbodyJoint >, gazebo::physics::SliderJoint< SimbodyJoint >, gazebo::physics::SimbodyHinge2Joint, gazebo::physics::SimbodyUniversalJoint, and gazebo::physics::SimbodyBallJoint.

virtual double gazebo::physics::SimbodyJoint::GetAttribute	(	const std::string &	_key,
		unsigned int	_index
	)

virtual

Get a non-generic parameter for the joint.

Parameters

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

Implements gazebo::physics::Joint.

virtual double gazebo::physics::SimbodyJoint::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 from gazebo::physics::Joint.

virtual JointWrench gazebo::physics::SimbodyJoint::GetForceTorque ( unsigned int _index )

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.

Implements gazebo::physics::Joint.

virtual LinkPtr gazebo::physics::SimbodyJoint::GetJointLink ( int _index ) const

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.

Implements gazebo::physics::Joint.

virtual math::Vector3 gazebo::physics::SimbodyJoint::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.

Implements gazebo::physics::Joint.

virtual math::Vector3 gazebo::physics::SimbodyJoint::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.

Implements gazebo::physics::Joint.

virtual void gazebo::physics::SimbodyJoint::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::Joint.

Reimplemented in gazebo::physics::SimbodySliderJoint, gazebo::physics::Hinge2Joint< SimbodyJoint >, gazebo::physics::BallJoint< SimbodyJoint >, gazebo::physics::ScrewJoint< SimbodyJoint >, gazebo::physics::UniversalJoint< SimbodyJoint >, gazebo::physics::HingeJoint< SimbodyJoint >, gazebo::physics::SliderJoint< SimbodyJoint >, gazebo::physics::SimbodyHingeJoint, gazebo::physics::SimbodyHinge2Joint, gazebo::physics::SimbodyUniversalJoint, gazebo::physics::SimbodyScrewJoint, and gazebo::physics::SimbodyBallJoint.

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

virtual

Reset the joint.

Reimplemented from gazebo::physics::Joint.

virtual void gazebo::physics::SimbodyJoint::RestoreSimbodyState ( SimTK::State & _state )

virtual

Reimplemented in gazebo::physics::SimbodyHingeJoint.

virtual void gazebo::physics::SimbodyJoint::SaveSimbodyState ( const SimTK::State & _state )

virtual

Reimplemented in gazebo::physics::SimbodyHingeJoint.

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

virtual

Set the anchor point.

Parameters

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

Implements gazebo::physics::Joint.

Reimplemented in gazebo::physics::ScrewJoint< SimbodyJoint >, and gazebo::physics::SliderJoint< SimbodyJoint >.

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

virtual

Set a parameter for the joint.

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

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.

Implements gazebo::physics::Joint.

virtual void gazebo::physics::SimbodyJoint::SetAxis	(	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).

Implements gazebo::physics::Joint.

Reimplemented in gazebo::physics::BallJoint< SimbodyJoint >, gazebo::physics::SimbodyHinge2Joint, gazebo::physics::SimbodyUniversalJoint, gazebo::physics::SimbodyScrewJoint, gazebo::physics::SimbodyHingeJoint, and gazebo::physics::SimbodySliderJoint.

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

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.

Implements gazebo::physics::Joint.

Reimplemented in gazebo::physics::SimbodySliderJoint, gazebo::physics::SimbodyUniversalJoint, gazebo::physics::SimbodyHinge2Joint, gazebo::physics::SimbodyHingeJoint, gazebo::physics::SimbodyScrewJoint, and gazebo::physics::SimbodyBallJoint.

virtual void gazebo::physics::SimbodyJoint::SetForce	(	int	_index,
		double	_effort
	)

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.

Implements gazebo::physics::Joint.

virtual void gazebo::physics::SimbodyJoint::SetForceImpl	(	int	_index,
		double	_force
	)

protectedpure 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 SetForceImpl to the same joint in the same time step will accumulate forces on that Joint).

Parameters

[in]	_index	Index of the axis.
[in]	_force	Force value. internal force, e.g. damping forces. This way, Joint::appliedForce keep track of external forces only.

Implemented in gazebo::physics::SimbodyHinge2Joint, gazebo::physics::SimbodyUniversalJoint, gazebo::physics::SimbodyScrewJoint, gazebo::physics::SimbodyHingeJoint, gazebo::physics::SimbodySliderJoint, and gazebo::physics::SimbodyBallJoint.

Member Data Documentation

SimTK::Constraint gazebo::physics::SimbodyJoint::constraint

: isValid() if we used a constraint to model this joint.

Set when we build the Simbody model. How this joint was modeled in the Simbody System. We used either a mobilizer or a constraint, but not both. The type of either one is the same as the joint type above.

SimTK::Force::MobilityLinearDamper gazebo::physics::SimbodyJoint::damper

: for enforcing joint damping forces.

Set when we build the Simbody model. : Make these arrays for multi-axis joints. : Also, consider moving this into individual joint type subclass so we can specify custom dampers for special joints like ball joints.

SimTK::Transform gazebo::physics::SimbodyJoint::defxAB

default mobilizer pose

bool gazebo::physics::SimbodyJoint::isReversed

: if mobilizer, did it reverse parent&child? Set when we build the Simbody model.

SimTK::Force::MobilityLinearStop gazebo::physics::SimbodyJoint::limitForce

: for enforcing joint stops Set when we build the Simbody model.

: Make these arrays for multi-axis joints. : Also, consider moving this into individual joint type subclass so we can specify custom dampers for special joints like ball joints.

SimTK::MobilizedBody gazebo::physics::SimbodyJoint::mobod

Use isValid() if we used a mobilizer Set when we build the Simbody model.

How this joint was modeled in the Simbody System. We used either a mobilizer or a constraint, but not both. The type of either one is the same as the joint type above.

bool gazebo::physics::SimbodyJoint::mustBreakLoopHere

Force Simbody to break a loop by using a weld constraint.

This flag is needed by SimbodyPhysics::MultibodyGraphMaker, so kept public.

bool gazebo::physics::SimbodyJoint::physicsInitialized

SimbodyPhysicsPtr gazebo::physics::SimbodyJoint::simbodyPhysics

protected

keep a pointer to the simbody physics engine for convenience

SimTK::MultibodySystem* gazebo::physics::SimbodyJoint::world

protected

Simbody Multibody System.

SimTK::Transform gazebo::physics::SimbodyJoint::xCB

child body frame to mobilizer frame

SimTK::Transform gazebo::physics::SimbodyJoint::xPA

Normally A=F, B=M.

But if reversed, then B=F, A=M. parent body frame to mobilizer frame

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

SimbodyJoint.hh

Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation