Description

Class for rotational spring-damper elements with the torque specified through a callback object.

The torque is applied in the current direction of the relative axis of rotation. While a rotational spring-damper can be associated with any pair of bodies in the system, it is typically used in cases where the mechanism kinematics are such that the two bodies have a single relative rotational degree of freedom (e.g, between two bodies connected through a revolute, cylindrical, or screw joint).

#include <ChLinkRotSpringCB.h>

Inheritance diagram for chrono::ChLinkRotSpringCB:

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Collaboration diagram for chrono::ChLinkRotSpringCB:

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

Public Member Functions
	ChLinkRotSpringCB (const ChLinkRotSpringCB &other)

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

double	GetRotSpringAngle () const
	Get the current rotation angle about the relative rotation axis.

const ChVector &	GetRotSpringAxis () const
	Get the current relative axis of rotation.

double	GetRotSpringSpeed () const
	Get the current relative angular speed about the common rotation axis.

double	GetRotSpringTorque () const
	Get the current generated torque.

void	RegisterTorqueFunctor (std::shared_ptr< TorqueFunctor > functor)
	Specify the callback object for calculating the torque.

virtual void	ArchiveOUT (ChArchiveOut &marchive) override
	Method to allow serialization of transient data to archives.

virtual void	ArchiveIN (ChArchiveIn &marchive) override
	Method to allow deserialization of transient data from archives. More...

Public Member Functions inherited from chrono::ChLinkMarkers
ChMarker *	GetMarker1 ()
	Return the 1st referenced marker (the 'slave' marker, owned by 1st body)

ChMarker *	GetMarker2 ()
	Return the 2nd referenced marker (the 'master' marker, owned by 2nd body)

virtual void	SetUpMarkers (ChMarker mark1, ChMarker mark2)
	set the two markers associated with this link

void	SetMarkID1 (int mid)

void	SetMarkID2 (int mid)

int	GetMarkID1 ()

int	GetMarkID2 ()

bool	ReferenceMarkers (ChMarker mark1, ChMarker mark2)
	Shortcut: set markers and marker IDs at once.

virtual void	Initialize (std::shared_ptr< ChMarker > mark1, std::shared_ptr< ChMarker > mark2)
	Use this function after link creation, to initialize the link from two markers to join. More...

virtual void	Initialize (std::shared_ptr< ChBody > mbody1, std::shared_ptr< ChBody > mbody2, const ChCoordsys<> &mpos)
	Use this function after link creation, to initialize the link from two joined rigid bodies. More...

virtual void	Initialize (std::shared_ptr< ChBody > mbody1, std::shared_ptr< ChBody > mbody2, bool pos_are_relative, const ChCoordsys<> &mpos1, const ChCoordsys<> &mpos2)
	Use this function after link creation, to initialize the link from two joined rigid bodies. More...

virtual ChCoordsys	GetLinkRelativeCoords () override
	Get the link coordinate system, expressed relative to Body2 (the 'master' body). More...

virtual ChFrame	GetAssetsFrame (unsigned int nclone=0) override
	Get the master coordinate system for the assets (this will return the absolute coordinate system of the 'master' marker2)

virtual void	UpdateRelMarkerCoords ()
	Updates auxiliary quantities for all relative degrees of freedom of the two markers.

virtual void	Update (double mytime, bool update_assets=true) override
	Complete link update: UpdateTime -> UpdateRelMarkerCoords -> UpdateForces.

virtual void	IntLoadResidual_F (const unsigned int off, ChVectorDynamic<> &R, const double c) override
	Adds force to residual R, as R= Fc NOTE: here the off offset in R is NOT used because add F at the TWO offsets of the two connected bodies, so it is assumed that offsets for Body1 and Body2 variables have been already set properly!

virtual void	ConstraintsFbLoadForces (double factor=1) override
	Overrides the empty behaviour of the parent ChLink implementation, which does not consider any user-imposed force between the two bodies. More...

const Coordsys &	GetRelM () const
	Relative position of marker 1 respect to marker 2.

const Coordsys &	GetRelM_dt () const
	Relative speed of marker 1 respect to marker 2.

const Coordsys &	GetRelM_dtdt () const
	Relative acceleration of marker 1 respect to marker 2.

double	GetRelAngle () const
	Relative rotation angle of marker 1 respect to marker 2 (best with revolute joints..).

const ChVector &	GetRelAxis () const
	Relative finite rotation axis of marker 1 respect to marker 2.

const ChVector &	GetRelRotaxis () const

const ChVector &	GetRelWvel () const
	Relative angular speed of marker 1 respect to marker 2.

const ChVector &	GetRelWacc () const
	Relative angular acceleration of marker 1 respect to marker 2.

double	GetDist () const
	Relative 'polar' distance of marker 1 respect to marker 2.

double	GetDist_dt () const
	Relative speed of marker 1 respect to marker 2, along the polar distance vector.

const ChVector &	GetC_force () const
	Get the total applied force accumulators (force, momentum) in link coords. More...

const ChVector &	GetC_torque () const

Public Member Functions inherited from chrono::ChLink
	ChLink (const ChLink &other)

int	GetLeftDOF ()
	Get the number of free degrees of freedom left by this link, between two bodies.

virtual int	GetNumCoords () override
	Get the number of scalar variables affected by constraints in this link.

ChBodyFrame *	GetBody1 ()
	Get the constrained body '1', the 'slave' body.

ChBodyFrame *	GetBody2 ()
	Get the constrained body '2', the 'master' body.

virtual ChCoordsys	GetLinkAbsoluteCoords () override
	Get the link coordinate system in absolute reference. More...

virtual ChVector	Get_react_force () override
	Get reaction force, expressed in link coordinate system.

virtual ChVector	Get_react_torque () override
	Get reaction torque, expressed in link coordinate system.

virtual int	RestoreRedundant ()
	If some constraint is redundant, return to normal state //*OBSOLETE*.

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.

bool	IsActive ()
	An important function! Tells if the link is currently active, in general, that is tells if it must be included into the system solver or not. 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...

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() and also add to new collision system / remove from old coll.system.

void	AddAsset (std::shared_ptr< ChAsset > masset)
	Add an optional asset (it can be used to define visualization shapes, es ChSphereShape, or textures, or custom attached properties that the user can define by creating his class inherited from ChAsset)

std::vector< std::shared_ptr< ChAsset > > &	GetAssets ()
	Access to the list of optional assets.

std::shared_ptr< ChAsset >	GetAssetN (unsigned int num)
	Access the Nth asset in the list of optional assets.

virtual unsigned int	GetAssetsFrameNclones ()
	Optionally, a ChPhysicsItem can return multiple asset coordinate systems; this can be helpful if, for example, when a ChPhysicsItem contains 'clones' with the same assets (ex. More...

virtual bool	GetCollide () const
	Tell if the object is subject to collision. More...

virtual void	SyncCollisionModels ()
	If this physical item contains one or more collision models, synchronize their coordinates and bounding boxes to the state of the item.

virtual void	AddCollisionModelsToSystem ()
	If this physical item contains one or more collision models, add them to the system's collision engine.

virtual void	RemoveCollisionModelsFromSystem ()
	If this physical item contains one or more collision models, remove them from the system's collision engine.

virtual void	GetTotalAABB (ChVector<> &bbmin, ChVector<> &bbmax)
	Get the entire AABB axis-aligned bounding box of the object. More...

virtual void	GetCenter (ChVector<> &mcenter)
	Get a symbolic 'center' of the object. More...

virtual void	StreamINstate (ChStreamInBinary &mstream)
	Method to deserialize only the state (position, speed) Must be implemented by child classes.

virtual void	StreamOUTstate (ChStreamOutBinary &mstream)
	Method to serialize only the state (position, speed) Must be implemented by child classes.

virtual void	Setup ()
	This might recompute the number of coordinates, DOFs, constraints, in case this might change (ex in ChAssembly), as well as state offsets of contained items (ex in ChMesh)

virtual void	SetNoSpeedNoAcceleration ()
	Set zero speed (and zero accelerations) in state, without changing the position. More...

virtual int	GetDOF ()
	Get the number of scalar coordinates (variables), if any, in this item. More...

virtual int	GetDOF_w ()
	Get the number of scalar coordinates of variables derivatives (usually = DOF, but might be different than DOF, ex. More...

virtual int	GetDOC ()
	Get the number of scalar constraints, if any, in this item.

virtual int	GetDOC_c ()
	Get the number of scalar constraints, if any, in this item (only bilateral constr.) Children classes might override this.

virtual int	GetDOC_d ()
	Get the number of scalar constraints, if any, in this item (only unilateral constr.) Children classes might override this.

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	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	IntLoadResidual_Mv (const unsigned int off, ChVectorDynamic<> &R, const ChVectorDynamic<> &w, const double c)
	Takes the Mv term, multiplying mass by a vector, scale and adds to R at given offset: R += cM*w. 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	IntToDescriptor (const unsigned int off_v, const ChStateDelta &v, const ChVectorDynamic<> &R, const unsigned int off_L, const ChVectorDynamic<> &L, const ChVectorDynamic<> &Qc)
	Prepare variables and constraints to accommodate a solution: More...

virtual void	IntFromDescriptor (const unsigned int off_v, ChStateDelta &v, const unsigned int off_L, ChVectorDynamic<> &L)
	After a solver solution, fetch values from variables and constraints into vectors: 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	InjectVariables (ChSystemDescriptor &mdescriptor)
	Tell to a system descriptor that there are variables of type ChVariables in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this.

virtual void	InjectConstraints (ChSystemDescriptor &mdescriptor)
	Tell to a system descriptor that there are constraints of type ChConstraint in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this.

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	ConstraintsLoadJacobians ()
	Adds the current jacobians in encapsulated ChConstraints.

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

virtual void	InjectKRMmatrices (ChSystemDescriptor &mdescriptor)
	Tell to a system descriptor that there are items of type ChKblock in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this.

virtual void	KRMmatricesLoad (double Kfactor, double Rfactor, double Mfactor)
	Adds the current stiffness K and damping R and mass M matrices in encapsulated ChKblock item(s), if any. More...

Public Member Functions inherited from chrono::ChObj
	ChObj (const ChObj &other)

int	GetIdentifier () const
	Gets the numerical identifier of the object.

void	SetIdentifier (int id)
	Sets the numerical identifier of the object.

double	GetChTime () const
	Gets the simulation time of this object.

void	SetChTime (double m_time)
	Sets the simulation time of this object.

const char *	GetName () const
	Gets the name of the object as C Ascii null-terminated string -for reading only!

void	SetName (const char myname[])
	Sets the name of this object, as ascii string.

std::string	GetNameString () const
	Gets the name of the object as C Ascii null-terminated string.

void	SetNameString (const std::string &myname)
	Sets the name of this object, as std::string.

void	MFlagsSetAllOFF (int &mflag)

void	MFlagsSetAllON (int &mflag)

void	MFlagSetON (int &mflag, int mask)

void	MFlagSetOFF (int &mflag, int mask)

int	MFlagGet (int &mflag, int mask)

virtual std::string &	ArchiveContainerName ()

Protected Member Functions
virtual void	UpdateForces (double time) override
	Include the rotational spring-damper custom torque.

Protected Member Functions inherited from chrono::ChLinkMarkers
	ChLinkMarkers (const ChLinkMarkers &other)

Protected Attributes
std::shared_ptr< TorqueFunctor >	m_torque_fun
	functor for torque calculation

double	m_torque
	resulting torque along relative axis of rotation

Protected Attributes inherited from chrono::ChLinkMarkers
ChMarker *	marker1
	slave coordsys

ChMarker *	marker2
	master coordsys, =0 if liked to ground

int	markID1
	unique identifier for markers 1 & 2,

int	markID2
	when using plugin dynamic hierarchies

Coordsys	relM
	relative marker position 2-1

Coordsys	relM_dt
	relative marker speed

Coordsys	relM_dtdt
	relative marker acceleration

double	relAngle
	relative angle of rotation

ChVector	relAxis
	relative axis of rotation

ChVector	relRotaxis
	relative rotaion vector =angle*axis

ChVector	relWvel
	relative angular speed

ChVector	relWacc
	relative angular acceleration

double	dist
	the distance between the two origins of markers,

double	dist_dt
	the speed between the two origins of markers

ChVector	C_force
	internal force applied by springs/dampers/actuators

ChVector	C_torque
	internal torque applied by springs/dampers/actuators

ChVector	PQw

ChVector	PQw_dt

ChVector	PQw_dtdt

ChQuaternion	q_AD

ChQuaternion	q_BC

ChQuaternion	q_8

ChVector	q_4

Protected Attributes inherited from chrono::ChLink
ChBodyFrame *	Body1
	first connected body

ChBodyFrame *	Body2
	second connected body

ChVector	react_force
	store the xyz reactions, expressed in local coordinate system of link;

ChVector	react_torque
	store the 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::vector< std::shared_ptr< ChAsset > >	assets
	set of assets

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
	the time of simulation for the object

Member Function Documentation

◆ ArchiveIN()

void chrono::ChLinkRotSpringCB::ArchiveIN ( ChArchiveIn & marchive )

overridevirtual

Method to allow deserialization of transient data from archives.

Method to allow de serialization of transient data from archives.

Reimplemented from chrono::ChLinkMarkers.

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

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

Description

Classes

Public Member Functions

Protected Member Functions

Protected Attributes

Member Function Documentation

◆ ArchiveIN()