Description

Class for translational spring-damper-actuator (TSDA) with the force optionally specified through a functor object.

By default, models a linear TSDA. Optionally, a ChLinkTSDA can have internal dynamics, described by a system of ODEs. The internal states are integrated simultaneous with the containing system and they can be accessed and used in the force calculation. ChLinkTSDA provides optional support for computing Jacobians of the generalized forces.

#include <ChLinkTSDA.h>

Inheritance diagram for chrono::ChLinkTSDA:

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Collaboration diagram for chrono::ChLinkTSDA:

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Classes
class	ForceFunctor
	Class to be used as a callback interface for calculating the general spring-damper force. More...

class	ODE
	Class to be used as a callback interface for specifying the ODE, y' = f(t,y); y(0) = y0. More...

Public Member Functions
	ChLinkTSDA (const ChLinkTSDA &other)

virtual ChLinkTSDA *	Clone () const override
	"Virtual" copy constructor (covariant return type).

void	SetRestLength (double len)
	Set spring rest (free) length. More...

void	SetSpringCoefficient (double k)
	Set spring coefficient (default: 0). More...

void	SetDampingCoefficient (double r)
	Set damping coefficient (default: 0). More...

void	SetActuatorForce (double f)
	Set constant actuation force (default: 0). More...

void	IsStiff (bool val)
	Declare the forces generated by this spring as stiff (default: false). More...

const ChVectorDynamic &	GetStates () const
	Get current states.

double	GetRestLength () const
	Get the spring rest (free) length.

double	GetLength () const
	Get current length.

double	GetDeformation () const
	Get current deformation.

double	GetVelocity () const
	Get current length rate of change.

double	GetForce () const
	Get current force (in the direction of the force element).

const ChVector3d &	GetPoint1Rel () const
	Get the endpoint location on 1st body (expressed in body 1 coordinate system)

const ChVector3d &	GetPoint1Abs () const
	Get the endpoint location on 1st body (expressed in absolute coordinate system)

const ChVector3d &	GetPoint2Rel () const
	Get the endpoint location on 2nd body (expressed in body 2 coordinate system)

const ChVector3d &	GetPoint2Abs () const
	Get the endpoint location on 1st body (expressed in absolute coordinate system)

virtual ChFrame	GetFrame1Rel () const override
	Get the link frame 1, relative to body 1.

virtual ChFrame	GetFrame2Rel () const override
	Get the link frame 2, relative to body 2.

double	GetSpringCoefficient () const
	Get the value of the spring coefficient. More...

double	GetDampingCoefficient () const
	Get the value of the damping coefficient. More...

double	GetActuatorForce () const
	Get the constant acutation force. More...

void	RegisterForceFunctor (std::shared_ptr< ForceFunctor > functor)
	Specify the functor object for calculating the force.

std::shared_ptr< ForceFunctor >	GetForceFunctor () const
	Return the functor object for calculating the force (may be empty).

void	RegisterODE (ODE *functor)
	Specify the functor object for calculating the ODE right-hand side.

void	Initialize (std::shared_ptr< ChBody > body1, std::shared_ptr< ChBody > body2, bool local, const ChVector3d &loc1, const ChVector3d &loc2)
	Initialize the spring, specifying the two bodies to be connected, the location of the two anchor points of each body (each expressed in body or absolute coordinates). 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.

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 ChWrenchd	GetReaction1 () const override
	Get the reaction force and torque on the 1st body, expressed in the link frame 1.

virtual ChWrenchd	GetReaction2 () const override
	Get the reaction force and torque on the 2nd body object, expressed in the link frame 2.

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 ChVectorDynamic	GetConstraintViolation () const
	Get the current constraint violations.

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	GetNumCoordsVelLevel ()
	Get the number of coordinates at the velocity level. More...

virtual unsigned int	GetNumConstraints ()
	Get the number of scalar constraints.

virtual unsigned int	GetNumConstraintsBilateral ()
	Get the number of bilateral 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	IntStateGatherReactions (const unsigned int off_L, ChVectorDynamic<> &L)
	From item's reaction forces to global reaction vector. More...

virtual void	IntStateScatterReactions (const unsigned int off_L, const ChVectorDynamic<> &L)
	From global reaction vector to item's reaction forces. 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_CqL (const unsigned int off_L, ChVectorDynamic<> &R, const ChVectorDynamic<> &L, const double c)
	Takes the term Cq'L, scale and adds to R at given offset: R += cCq'*L. More...

virtual void	IntLoadConstraint_C (const unsigned int off, ChVectorDynamic<> &Qc, const double c, bool do_clamp, double recovery_clamp)
	Takes the term C, scale and adds to Qc at given offset: Qc += c*C. 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	InjectConstraints (ChSystemDescriptor &descriptor)
	Register with the given system descriptor any ChConstraint objects associated with this item.

virtual void	LoadConstraintJacobians ()
	Compute and load current Jacobians in encapsulated ChConstraint objects.

virtual void	ConstraintsBiReset ()
	Sets to zero the known term (b_i) of encapsulated ChConstraints.

virtual void	ConstraintsBiLoad_C (double factor=1, double recovery_clamp=0.1, bool do_clamp=false)
	Adds the current C (constraint violation) to the known term (b_i) of encapsulated ChConstraints.

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	ConstraintsFetch_react (double factor=1)
	Fetches the reactions from the lagrangian multiplier (l_i) of encapsulated ChConstraints. More...

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 ()

Friends
class	ChSystemMulticore

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

◆ GetActuatorForce()

double chrono::ChLinkTSDA::GetActuatorForce ( ) const

inline

Get the constant acutation force.

Meaningful only if no force functor is provided.

◆ GetDampingCoefficient()

double chrono::ChLinkTSDA::GetDampingCoefficient ( ) const

inline

Get the value of the damping coefficient.

Meaningful only if no force functor is provided.

◆ GetSpringCoefficient()

double chrono::ChLinkTSDA::GetSpringCoefficient ( ) const

inline

Get the value of the spring coefficient.

Meaningful only if no force functor is provided.

◆ Initialize()

void chrono::ChLinkTSDA::Initialize	(	std::shared_ptr< ChBody >	body1,
		std::shared_ptr< ChBody >	body2,
		bool	local,
		const ChVector3d &	loc1,
		const ChVector3d &	loc2
	)

Initialize the spring, specifying the two bodies to be connected, the location of the two anchor points of each body (each expressed in body or absolute coordinates).

Unless SetRestLength() is explicitly called, the TSDA rest length is calculated from the initial configuration.

Parameters

body1	first body to link
body2	second body to link
local	if true, point locations are relative to bodies
loc1	point on 1st body (rel. or abs., see flag above)
loc2	point on 2nd body (rel. or abs., see flag above)

◆ IsStiff()

void chrono::ChLinkTSDA::IsStiff ( bool val )

inline

Declare the forces generated by this spring as stiff (default: false).

If stiff, Jacobian information will be generated.

◆ SetActuatorForce()

void chrono::ChLinkTSDA::SetActuatorForce ( double f )

inline

Set constant actuation force (default: 0).

Used only if no force functor is provided.

◆ SetDampingCoefficient()

void chrono::ChLinkTSDA::SetDampingCoefficient ( double r )

inline

Set damping coefficient (default: 0).

Used only if no force functor is provided.

◆ SetRestLength()

void chrono::ChLinkTSDA::SetRestLength ( double len )

Set spring rest (free) length.

By default, this is calculated from the initial configuration.

◆ SetSpringCoefficient()

void chrono::ChLinkTSDA::SetSpringCoefficient ( double k )

inline

Set spring coefficient (default: 0).

Used only if no force functor is provided.

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

/builds/uwsbel/chrono/src/chrono/physics/ChLinkTSDA.h
/builds/uwsbel/chrono/src/chrono/physics/ChLinkTSDA.cpp

Description

Classes

Public Member Functions

Friends

Additional Inherited Members

Member Function Documentation

◆ GetActuatorForce()

◆ GetDampingCoefficient()

◆ GetSpringCoefficient()

◆ Initialize()

◆ IsStiff()

◆ SetActuatorForce()

◆ SetDampingCoefficient()

◆ SetRestLength()

◆ SetSpringCoefficient()