chrono::ChLinkRevoluteTranslational Class Reference

Description

Class for modeling a composite revolute-translational joint between two ChBodyFrame objects.

This joint is defined through a point and direction on the first body (the revolute side), a point and two mutually orthogonal directions on the second body (the translational side), and a distance.

#include <ChLinkRevoluteTranslational.h>

Inheritance diagram for chrono::ChLinkRevoluteTranslational:

Collaboration diagram for chrono::ChLinkRevoluteTranslational:

Public Member Functions
	ChLinkRevoluteTranslational (const ChLinkRevoluteTranslational &other)
virtual ChLinkRevoluteTranslational *	Clone () const override
	"Virtual" copy constructor (covariant return type).
virtual unsigned int	GetNumConstraintsBilateral () override
	Get the number of (bilateral) constraints introduced by this joint.
double	GetImposedDistance () const
	Get the imposed distance (length of massless connector).
double	GetCurrentDistance () const
	Get the current distance between the two points.
ChVector3d	GetPoint1Abs () const
	Get the point on m_body1 (revolute side), expressed in absolute coordinate system.
ChVector3d	GetDirZ1Abs () const
	Get the direction of the revolute joint, expressed in absolute coordinate system.
ChVector3d	GetPoint2Abs () const
	Get the point on m_body2 (translational side), expressed in absolute coordinate system.
ChVector3d	GetDirX2Abs () const
	Get the first direction of the translational joint, expressed in absolute coordinate system. More...
ChVector3d	GetDirY2Abs () const
	Get the second direction of the translational joint, expressed in absolute coordinate system. More...
virtual ChFrame	GetFrame1Rel () const override
	Get the link frame 1, relative to body 1. More...
virtual ChFrame	GetFrame2Rel () const override
	Get the link frame 2, relative to body 2.
virtual ChWrenchd	GetReaction1 () const override
	Get the reaction force and torque on the 1st body, expressed in the link frame 1. More...
virtual ChWrenchd	GetReaction2 () const override
	Get the reaction force and torque on the 2nd body, expressed in the link frame 2. More...
virtual ChVectorDynamic	GetConstraintViolation () const override
	Get the joint violation (residuals of the constraint equations)
void	Initialize (std::shared_ptr< ChBody > body1, std::shared_ptr< ChBody > body2, const ChCoordsys<> &csys, double distance)
	Initialize this joint by specifying the two bodies to be connected, a coordinate system specified in the absolute frame, and the distance of the massless connector. More...
void	Initialize (std::shared_ptr< ChBody > body1, std::shared_ptr< ChBody > body2, bool local, const ChVector3d &p1, const ChVector3d &dirZ1, const ChVector3d &p2, const ChVector3d &dirX2, const ChVector3d &dirY2, bool auto_distance=true, double distance=0)
	Initialize this joint by specifying the two bodies to be connected, a point and a direction on body1 defining the revolute joint, and two directions and a point on the second body defining the translational joint. More...
virtual void	Update (double time, bool update_assets=true) override
	Perform the update of this joint at the specified time: compute jacobians, constraint violations, etc. More...
virtual void	ArchiveOut (ChArchiveOut &archive_out) override
	Method to allow serialization of transient data to archives.
virtual void	ArchiveIn (ChArchiveIn &archive_in) override
	Method to allow deserialization of transient data from archives. More...
Public Member Functions inherited from chrono::ChLink
	ChLink (const ChLink &other)
virtual unsigned int	GetNumAffectedCoords () override
	Get the number of scalar variables affected by constraints in this link.
ChBodyFrame *	GetBody1 () const
	Get the constrained body 1.
ChBodyFrame *	GetBody2 () const
	Get the constrained body 2.
virtual ChFramed	GetFrame1Abs () const override
	Get the link frame 1, on body 1, expressed in the absolute frame.
virtual ChFramed	GetFrame2Abs () const override
	Get the link frame 2, on body 2, expressed in the absolute frame.
virtual void	UpdateTime (double mytime)
	Given new time, current body state, update time-dependent quantities in link state, for example motion laws, moving markers, etc. More...
virtual void	Update (bool update_assets=true) override
	As above, but with current time.
virtual void	UpdatedExternalTime (double prevtime, double time)
	Called from a external package (i.e. a plugin, a CAD app.) to report that time has changed.
Public Member Functions inherited from chrono::ChLinkBase
	ChLinkBase (const ChLinkBase &other)
bool	IsValid ()
	Tells if the link data is currently valid. More...
void	SetValid (bool mon)
	Set the status of link validity.
bool	IsDisabled ()
	Tells if all constraints of this link are currently turned on or off by the user.
virtual void	SetDisabled (bool mdis)
	User can use this to enable/disable all the constraint of the link as desired.
bool	IsBroken ()
	Tells if the link is broken, for excess of pulling/pushing.
virtual void	SetBroken (bool mon)
	Set the 'broken' status vof this link.
virtual bool	IsActive () const override
	Return true if the link is currently active and thereofre included into the system solver. More...
virtual bool	IsRequiringWaking ()
	Tells if this link requires that the connected ChBody objects must be waken if they are sleeping. More...
virtual ChFrame	GetVisualModelFrame (unsigned int nclone=0) const override
	Get the reference frame (expressed in and relative to the absolute frame) of the visual model. More...
Public Member Functions inherited from chrono::ChPhysicsItem
	ChPhysicsItem (const ChPhysicsItem &other)
ChSystem *	GetSystem () const
	Get the pointer to the parent ChSystem().
virtual void	SetSystem (ChSystem *m_system)
	Set the pointer to the parent ChSystem(). More...
void	AddVisualModel (std::shared_ptr< ChVisualModel > model)
	Add an (optional) visualization model. More...
std::shared_ptr< ChVisualModel >	GetVisualModel () const
	Access the visualization model (if any). More...
void	AddVisualShape (std::shared_ptr< ChVisualShape > shape, const ChFrame<> &frame=ChFrame<>())
	Add the specified visual shape to the visualization model. More...
std::shared_ptr< ChVisualShape >	GetVisualShape (unsigned int i) const
	Access the specified visualization shape in the visualization model (if any). More...
void	AddVisualShapeFEA (std::shared_ptr< ChVisualShapeFEA > shapeFEA)
	Add the specified FEA visualization object to the visualization model. More...
std::shared_ptr< ChVisualShapeFEA >	GetVisualShapeFEA (unsigned int i) const
	Access the specified FEA visualization object in the visualization model (if any). More...
virtual unsigned int	GetNumVisualModelClones () const
	Return the number of clones of the visual model associated with this physics item. More...
void	AddCamera (std::shared_ptr< ChCamera > camera)
	Attach a ChCamera to this physical item. More...
std::vector< std::shared_ptr< ChCamera > >	GetCameras () const
	Get the set of cameras attached to this physics item.
virtual bool	IsCollisionEnabled () const
	Tell if the object is subject to collision. More...
virtual void	AddCollisionModelsToSystem (ChCollisionSystem *coll_sys) const
	Add to the provided collision system any collision models managed by this physics item. More...
virtual void	RemoveCollisionModelsFromSystem (ChCollisionSystem *coll_sys) const
	Remove from the provided collision system any collision models managed by this physics item. More...
virtual void	SyncCollisionModels ()
	Synchronize the position and bounding box of any collsion models managed by this physics item.
virtual ChAABB	GetTotalAABB () const
	Get the axis-aligned bounding box (AABB) of this object. More...
virtual ChVector3d	GetCenter () const
	Get a symbolic 'center' of the object. More...
virtual void	Setup ()
	Perform setup operations. More...
void	UpdateVisualModel ()
	Utility function to update only the associated visual assets (if any).
virtual void	ForceToRest ()
	Set zero speed (and zero accelerations) in state, without changing the position. More...
virtual unsigned int	GetNumCoordsPosLevel ()
	Get the number of coordinates at the position level. More...
virtual unsigned int	GetNumCoordsVelLevel ()
	Get the number of coordinates at the velocity level. More...
virtual unsigned int	GetNumConstraints ()
	Get the number of scalar constraints.
virtual unsigned int	GetNumConstraintsUnilateral ()
	Get the number of unilateral scalar constraints.
unsigned int	GetOffset_x ()
	Get offset in the state vector (position part)
unsigned int	GetOffset_w ()
	Get offset in the state vector (speed part)
unsigned int	GetOffset_L ()
	Get offset in the lagrangian multipliers.
void	SetOffset_x (const unsigned int moff)
	Set offset in the state vector (position part) Note: only the ChSystem::Setup function should use this.
void	SetOffset_w (const unsigned int moff)
	Set offset in the state vector (speed part) Note: only the ChSystem::Setup function should use this.
void	SetOffset_L (const unsigned int moff)
	Set offset in the lagrangian multipliers Note: only the ChSystem::Setup function should use this.
virtual void	IntStateGather (const unsigned int off_x, ChState &x, const unsigned int off_v, ChStateDelta &v, double &T)
	From item's state to global state vectors y={x,v} pasting the states at the specified offsets. More...
virtual void	IntStateScatter (const unsigned int off_x, const ChState &x, const unsigned int off_v, const ChStateDelta &v, const double T, bool full_update)
	From global state vectors y={x,v} to item's state (and update) fetching the states at the specified offsets. More...
virtual void	IntStateGatherAcceleration (const unsigned int off_a, ChStateDelta &a)
	From item's state acceleration to global acceleration vector. More...
virtual void	IntStateScatterAcceleration (const unsigned int off_a, const ChStateDelta &a)
	From global acceleration vector to item's state acceleration. More...
virtual void	IntStateIncrement (const unsigned int off_x, ChState &x_new, const ChState &x, const unsigned int off_v, const ChStateDelta &Dv)
	Computes x_new = x + Dt , using vectors at specified offsets. More...
virtual void	IntStateGetIncrement (const unsigned int off_x, const ChState &x_new, const ChState &x, const unsigned int off_v, ChStateDelta &Dv)
	Computes Dt = x_new - x, using vectors at specified offsets. More...
virtual void	IntLoadResidual_F (const unsigned int off, ChVectorDynamic<> &R, const double c)
	Takes the F force term, scale and adds to R at given offset: R += c*F. More...
virtual void	IntLoadResidual_Mv (const unsigned int off, ChVectorDynamic<> &R, const ChVectorDynamic<> &w, const double c)
	Takes the M*v term, multiplying mass by a vector, scale and adds to R at given offset: R += c*M*w. More...
virtual void	IntLoadLumpedMass_Md (const unsigned int off, ChVectorDynamic<> &Md, double &err, const double c)
	Adds the lumped mass to a Md vector, representing a mass diagonal matrix. More...
virtual void	IntLoadConstraint_Ct (const unsigned int off, ChVectorDynamic<> &Qc, const double c)
	Takes the term Ct, scale and adds to Qc at given offset: Qc += c*Ct. More...
virtual void	InjectVariables (ChSystemDescriptor &descriptor)
	Register with the given system descriptor any ChVariable objects associated with this item.
virtual void	InjectKRMMatrices (ChSystemDescriptor &descriptor)
	Register with the given system descriptor any ChKRMBlock objects associated with this item.
virtual void	LoadKRMMatrices (double Kfactor, double Rfactor, double Mfactor)
	Compute and load current stiffnes (K), damping (R), and mass (M) matrices in encapsulated ChKRMBlock objects. More...
virtual void	VariablesFbReset ()
	Sets the 'fb' part (the known term) of the encapsulated ChVariables to zero.
virtual void	VariablesFbLoadForces (double factor=1)
	Adds the current forces (applied to item) into the encapsulated ChVariables, in the 'fb' part: qf+=forces*factor.
virtual void	VariablesQbLoadSpeed ()
	Initialize the 'qb' part of the ChVariables with the current value of speeds. More...
virtual void	VariablesFbIncrementMq ()
	Adds M*q (masses multiplied current 'qb') to Fb, ex. More...
virtual void	VariablesQbSetSpeed (double step=0)
	Fetches the item speed (ex. More...
virtual void	VariablesQbIncrementPosition (double step)
	Increment item positions by the 'qb' part of the ChVariables, multiplied by a 'step' factor. More...
virtual void	ConstraintsBiLoad_Ct (double factor=1)
	Adds the current Ct (partial t-derivative, as in C_dt=0-> [Cq]*q_dt=-Ct) to the known term (b_i) of encapsulated ChConstraints.
virtual void	ConstraintsBiLoad_Qc (double factor=1)
	Adds the current Qc (the vector of C_dtdt=0 -> [Cq]*q_dtdt=Qc ) to the known term (b_i) of encapsulated ChConstraints.
virtual void	ConstraintsFbLoadForces (double factor=1)
	Adds the current link-forces, if any, (caused by springs, etc.) to the 'fb' vectors of the ChVariables referenced by encapsulated ChConstraints.
Public Member Functions inherited from chrono::ChObj
	ChObj (const ChObj &other)
int	GetIdentifier () const
	Get the unique integer identifier of this object. More...
void	SetTag (int tag)
	Set an object integer tag (default: -1). More...
int	GetTag () const
	Get the tag of this object.
void	SetName (const std::string &myname)
	Set the name of this object.
const std::string &	GetName () const
	Get the name of this object.
double	GetChTime () const
	Gets the simulation time of this object.
void	SetChTime (double m_time)
	Sets the simulation time of this object.
virtual std::string &	ArchiveContainerName ()

Additional Inherited Members
Protected Member Functions inherited from chrono::ChObj
int	GenerateUniqueIdentifier ()
Protected Attributes inherited from chrono::ChLink
ChBodyFrame *	m_body1
	first connected body
ChBodyFrame *	m_body2
	second connected body
ChVector3d	react_force
	xyz reactions, expressed in local coordinate system of link;
ChVector3d	react_torque
	torque reactions, expressed in local coordinate system of link;
Protected Attributes inherited from chrono::ChLinkBase
bool	disabled
	all constraints of link disabled because of user needs
bool	valid
	link data is valid
bool	broken
	link is broken because of excessive pulling/pushing.
Protected Attributes inherited from chrono::ChPhysicsItem
ChSystem *	system
	parent system
std::shared_ptr< ChVisualModelInstance >	vis_model_instance
	instantiated visualization model
std::vector< std::shared_ptr< ChCamera > >	cameras
	set of cameras
unsigned int	offset_x
	offset in vector of state (position part)
unsigned int	offset_w
	offset in vector of state (speed part)
unsigned int	offset_L
	offset in vector of lagrangian multipliers
Protected Attributes inherited from chrono::ChObj
double	ChTime
	object simulation time
std::string	m_name
	object name
int	m_identifier
	object unique identifier
int	m_tag
	user-supplied tag

Member Function Documentation

ArchiveIn()

void chrono::ChLinkRevoluteTranslational::ArchiveIn ( ChArchiveIn &  archive_in )

overridevirtual

Method to allow deserialization of transient data from archives.

Method to allow de serialization of transient data from archives.

Reimplemented from chrono::ChLink.

GetDirX2Abs()

ChVector3d chrono::ChLinkRevoluteTranslational::GetDirX2Abs ( ) const

inline

Get the first direction of the translational joint, expressed in absolute coordinate system.

The translational axis is orthogonal to the direction.

GetDirY2Abs()

ChVector3d chrono::ChLinkRevoluteTranslational::GetDirY2Abs ( ) const

inline

Get the second direction of the translational joint, expressed in absolute coordinate system.

The translational axis is orthogonal to the direction.

GetFrame1Rel()

ChFrame chrono::ChLinkRevoluteTranslational::GetFrame1Rel ( ) const

overridevirtual

Get the link frame 1, relative to body 1.

This frame, defined on body 1 (the revolute side), is centered at the revolute joint location, has its X axis along the joint connector, and its Z axis aligned with the revolute axis.

Implements chrono::ChLink.

GetReaction1()

ChWrenchd chrono::ChLinkRevoluteTranslational::GetReaction1 ( ) const

overridevirtual

Get the reaction force and torque on the 1st body, expressed in the link frame 1.

NOT YET IMPLEMENTED!

Reimplemented from chrono::ChLink.

GetReaction2()

ChWrenchd chrono::ChLinkRevoluteTranslational::GetReaction2 ( ) const

overridevirtual

Get the reaction force and torque on the 2nd body, expressed in the link frame 2.

NOT YET IMPLEMENTED!

Reimplemented from chrono::ChLink.

Initialize() [1/2]

void chrono::ChLinkRevoluteTranslational::Initialize	(	std::shared_ptr< ChBody >	body1,
		std::shared_ptr< ChBody >	body2,
		bool	local,
		const ChVector3d &	p1,
		const ChVector3d &	dirZ1,
		const ChVector3d &	p2,
		const ChVector3d &	dirX2,
		const ChVector3d &	dirY2,
		bool	auto_distance = true,
		double	distance = 0
	)

Initialize this joint by specifying the two bodies to be connected, a point and a direction on body1 defining the revolute joint, and two directions and a point on the second body defining the translational joint.

If local = true, it is assumed that these quantities are specified in the local body frames. Otherwise, it is assumed that they are specified in the absolute frame. The imposed distance between the two points can be either inferred from the provided configuration (auto_distance = true) or specified explicitly.

Parameters

body1	first frame (revolute side)
body2	second frame (spherical side)
local	true if data given in body local frames
p1	point on first frame (revolute side)
dirZ1	direction of revolute on first frame
p2	point on second frame (translational side)
dirX2	first direction of translational joint
dirY2	second direction of translational joint
auto_distance	true if imposed distance equal to distance between axes
distance	imposed distance (used only if auto_distance = false)

Initialize() [2/2]

void chrono::ChLinkRevoluteTranslational::Initialize	(	std::shared_ptr< ChBody >	body1,
		std::shared_ptr< ChBody >	body2,
		const ChCoordsys<> &	csys,
		double	distance
	)

Initialize this joint by specifying the two bodies to be connected, a coordinate system specified in the absolute frame, and the distance of the massless connector.

The composite joint is constructed such that the revolute joint is centered at the origin of the specified coordinate system. The revolute joint rotates about the z axis, the translational joint moves along the y axis, and the translation axis is at the specified distance along the x axis.

Parameters

body1	first frame (revolute side)
body2	second frame (translational side)
csys	joint coordinate system (in absolute frame)
distance	imposed distance

Update()

void chrono::ChLinkRevoluteTranslational::Update ( double  time, bool  update_assets = true  )

overridevirtual

Perform the update of this joint at the specified time: compute jacobians, constraint violations, etc.

and cache in internal structures

Reimplemented from chrono::ChLink.

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

• /builds/uwsbel/chrono/src/chrono/physics/ChLinkRevoluteTranslational.h
• /builds/uwsbel/chrono/src/chrono/physics/ChLinkRevoluteTranslational.cpp