Description

Class representing a container of many non-smooth contacts.

Implemented using linked lists of ChContactNSC objects (that is, contacts between two ChContactable objects, with 3 reactions). It might also contain ChContactNSCrolling objects (extended versions of ChContactNSC, with 6 reactions, that account also for rolling and spinning resistance), but also for '6dof vs 6dof' contactables.

#include <ChContactContainerNSC.h>

Inheritance diagram for chrono::ChContactContainerNSC:

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Collaboration diagram for chrono::ChContactContainerNSC:

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Public Types
typedef ChContactNSC< ChContactable_1vars< 6 >, ChContactable_1vars< 6 > >	ChContactNSC_6_6

typedef ChContactNSC< ChContactable_1vars< 6 >, ChContactable_1vars< 3 > >	ChContactNSC_6_3

typedef ChContactNSC< ChContactable_1vars< 3 >, ChContactable_1vars< 3 > >	ChContactNSC_3_3

typedef ChContactNSC< ChContactable_3vars< 3, 3, 3 >, ChContactable_1vars< 3 > >	ChContactNSC_333_3

typedef ChContactNSC< ChContactable_3vars< 3, 3, 3 >, ChContactable_1vars< 6 > >	ChContactNSC_333_6

typedef ChContactNSC< ChContactable_3vars< 3, 3, 3 >, ChContactable_3vars< 3, 3, 3 > >	ChContactNSC_333_333

typedef ChContactNSC< ChContactable_3vars< 6, 6, 6 >, ChContactable_1vars< 3 > >	ChContactNSC_666_3

typedef ChContactNSC< ChContactable_3vars< 6, 6, 6 >, ChContactable_1vars< 6 > >	ChContactNSC_666_6

typedef ChContactNSC< ChContactable_3vars< 6, 6, 6 >, ChContactable_3vars< 3, 3, 3 > >	ChContactNSC_666_333

typedef ChContactNSC< ChContactable_3vars< 6, 6, 6 >, ChContactable_3vars< 6, 6, 6 > >	ChContactNSC_666_666

typedef ChContactNSCrolling< ChContactable_1vars< 6 >, ChContactable_1vars< 6 > >	ChContactNSCrolling_6_6

Public Member Functions
	ChContactContainerNSC (const ChContactContainerNSC &other)

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

virtual int	GetNcontacts () const override
	Report the number of added contacts.

virtual void	RemoveAllContacts () override
	Remove (delete) all contained contact data.

virtual void	BeginAddContact () override
	The collision system will call BeginAddContact() before adding all contacts (for example with AddContact() or similar). More...

virtual void	AddContact (const collision::ChCollisionInfo &mcontact) override
	Add a contact between two frames.

virtual void	EndAddContact () override
	The collision system will call BeginAddContact() after adding all contacts (for example with AddContact() or similar). More...

virtual void	ReportAllContacts (ReportContactCallback *mcallback) override
	Scan all the contacts and for each contact executes the OnReportContact() function of the provided callback object.

virtual int	GetDOC_d () override
	Report the number of scalar unilateral constraints. More...

virtual void	Update (double mtime, bool update_assets=true) override
	Update state of this contact container: compute jacobians, violations, etc. More...

virtual void	ComputeContactForces () override
	Compute contact forces on all contactable objects in this container. More...

virtual ChVector	GetContactableForce (ChContactable *contactable) override
	Return the resultant contact force acting on the specified contactable object.

virtual ChVector	GetContactableTorque (ChContactable *contactable) override
	Return the resultant contact torque acting on the specified contactable object.

virtual void	IntStateGatherReactions (const unsigned int off_L, ChVectorDynamic<> &L) override
	From item's reaction forces to global reaction vector. More...

virtual void	IntStateScatterReactions (const unsigned int off_L, const ChVectorDynamic<> &L) override
	From global reaction vector to item's reaction forces. More...

virtual void	IntLoadResidual_CqL (const unsigned int off_L, ChVectorDynamic<> &R, const ChVectorDynamic<> &L, const double c) override
	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) override
	Takes the term C, scale and adds to Qc at given offset: Qc += c*C. 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) override
	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) override
	After a solver solution, fetch values from variables and constraints into vectors: More...

virtual void	InjectConstraints (ChSystemDescriptor &mdescriptor) override
	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 () override
	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) override
	Adds the current C (constraint violation) to the known term (b_i) of encapsulated ChConstraints.

virtual void	ConstraintsLoadJacobians () override
	Adds the current jacobians in encapsulated ChConstraints.

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

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

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

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

virtual void	RegisterAddContactCallback (AddContactCallback *mcallback)
	Specify a callback object to be used each time a contact point is added to the container. More...

virtual AddContactCallback *	GetAddContactCallback ()
	Get the callback object to be used each time a contact point is added to the container.

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 ChFrame	GetAssetsFrame (unsigned int nclone=0)
	Get the master coordinate system for assets that have some geometric meaning. More...

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	Update (bool update_assets=true)
	As above, but does not require updating of time-dependent data. More...

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.

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)
	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	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 Mv term, multiplying mass by a vector, scale and adds to R at given offset: R += cM*w. 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	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	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.

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 Attributes
std::list< ChContactNSC_6_6 * >	contactlist_6_6

std::list< ChContactNSC_6_3 * >	contactlist_6_3

std::list< ChContactNSC_3_3 * >	contactlist_3_3

std::list< ChContactNSC_333_3 * >	contactlist_333_3

std::list< ChContactNSC_333_6 * >	contactlist_333_6

std::list< ChContactNSC_333_333 * >	contactlist_333_333

std::list< ChContactNSC_666_3 * >	contactlist_666_3

std::list< ChContactNSC_666_6 * >	contactlist_666_6

std::list< ChContactNSC_666_333 * >	contactlist_666_333

std::list< ChContactNSC_666_666 * >	contactlist_666_666

std::list< ChContactNSCrolling_6_6 * >	contactlist_6_6_rolling

int	n_added_6_6

int	n_added_6_3

int	n_added_3_3

int	n_added_333_3

int	n_added_333_6

int	n_added_333_333

int	n_added_666_3

int	n_added_666_6

int	n_added_666_333

int	n_added_666_666

int	n_added_6_6_rolling

std::list< ChContactNSC_6_6 * >::iterator	lastcontact_6_6

std::list< ChContactNSC_6_3 * >::iterator	lastcontact_6_3

std::list< ChContactNSC_3_3 * >::iterator	lastcontact_3_3

std::list< ChContactNSC_333_3 * >::iterator	lastcontact_333_3

std::list< ChContactNSC_333_6 * >::iterator	lastcontact_333_6

std::list< ChContactNSC_333_333 * >::iterator	lastcontact_333_333

std::list< ChContactNSC_666_3 * >::iterator	lastcontact_666_3

std::list< ChContactNSC_666_6 * >::iterator	lastcontact_666_6

std::list< ChContactNSC_666_333 * >::iterator	lastcontact_666_333

std::list< ChContactNSC_666_666 * >::iterator	lastcontact_666_666

std::list< ChContactNSCrolling_6_6 * >::iterator	lastcontact_6_6_rolling

std::unordered_map< ChContactable *, ForceTorque >	contact_forces

Protected Attributes inherited from chrono::ChContactContainer
AddContactCallback *	add_contact_callback

ReportContactCallback *	report_contact_callback

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

Additional Inherited Members
Protected Member Functions inherited from chrono::ChContactContainer
template<class Tcont >
void	SumAllContactForces (std::list< Tcont * > &contactlist, std::unordered_map< ChContactable *, ForceTorque > &contactforces)
	Utility function to accumulate contact forces from a specified list of contacts. More...

Member Function Documentation

◆ ArchiveIN()

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

overridevirtual

Method to allow de-serialization of transient data from archives.

Method to allow de serialization of transient data from archives.

Reimplemented from chrono::ChContactContainer.

◆ BeginAddContact()

void chrono::ChContactContainerNSC::BeginAddContact ( )

overridevirtual

The collision system will call BeginAddContact() before adding all contacts (for example with AddContact() or similar).

Instead of simply deleting all list of the previous contacts, this optimized implementation rewinds the link iterator to begin and tries to reuse previous contact objects until possible, to avoid too much allocation/deallocation.

Reimplemented from chrono::ChContactContainer.

◆ ComputeContactForces()

void chrono::ChContactContainerNSC::ComputeContactForces ( )

overridevirtual

Compute contact forces on all contactable objects in this container.

This function caches contact forces in a map.

Reimplemented from chrono::ChContactContainer.

◆ ConstraintsFetch_react()

void chrono::ChContactContainerNSC::ConstraintsFetch_react ( double factor = 1 )

overridevirtual

Fetches the reactions from the lagrangian multiplier (l_i) of encapsulated ChConstraints.

Mostly used after the solver provided the solution in ChConstraints. Also, should convert the reactions obtained from dynamical simulation, from link space to intuitive react_force and react_torque.

Reimplemented from chrono::ChPhysicsItem.

◆ EndAddContact()

void chrono::ChContactContainerNSC::EndAddContact ( )

overridevirtual

The collision system will call BeginAddContact() after adding all contacts (for example with AddContact() or similar).

This optimized version purges the end of the list of contacts that were not reused (if any).

Reimplemented from chrono::ChContactContainer.

◆ GetDOC_d()

virtual int chrono::ChContactContainerNSC::GetDOC_d ( )

inlineoverridevirtual

Report the number of scalar unilateral constraints.

Note: friction constraints aren't exactly unilaterals, but they are still counted.

Reimplemented from chrono::ChPhysicsItem.

◆ IntFromDescriptor()

void chrono::ChContactContainerNSC::IntFromDescriptor	(	const unsigned int	off_v,
		ChStateDelta &	v,
		const unsigned int	off_L,
		ChVectorDynamic<> &	L
	)

overridevirtual

After a solver solution, fetch values from variables and constraints into vectors:

Parameters

off_v	offset for v
v	vector to where the q 'unknowns' term of the variables will be copied
off_L	offset for L
L	vector to where L 'lagrangian ' term of the constraints will be copied

Reimplemented from chrono::ChPhysicsItem.

◆ IntLoadConstraint_C()

void chrono::ChContactContainerNSC::IntLoadConstraint_C	(	const unsigned int	off,
		ChVectorDynamic<> &	Qc,
		const double	c,
		bool	do_clamp,
		double	recovery_clamp
	)

overridevirtual

Takes the term C, scale and adds to Qc at given offset: Qc += c*C.

Parameters

off	offset in Qc residual
Qc	result: the Qc residual, Qc += c*C
c	a scaling factor
do_clamp	apply clamping to c*C?
recovery_clamp	value for min/max clamping of c*C

Reimplemented from chrono::ChPhysicsItem.

◆ IntLoadResidual_CqL()

void chrono::ChContactContainerNSC::IntLoadResidual_CqL	(	const unsigned int	off_L,
		ChVectorDynamic<> &	R,
		const ChVectorDynamic<> &	L,
		const double	c
	)

overridevirtual

Takes the term Cq'*L, scale and adds to R at given offset: R += c*Cq'*L.

Parameters

off_L	offset in L multipliers
R	result: the R residual, R += cCq'L
L	the L vector
c	a scaling factor

Reimplemented from chrono::ChPhysicsItem.

◆ IntStateGatherReactions()

void chrono::ChContactContainerNSC::IntStateGatherReactions	(	const unsigned int	off_L,
		ChVectorDynamic<> &	L
	)

overridevirtual

From item's reaction forces to global reaction vector.

Parameters

off_L	offset in L vector
L	L vector of reaction forces

Reimplemented from chrono::ChPhysicsItem.

◆ IntStateScatterReactions()

void chrono::ChContactContainerNSC::IntStateScatterReactions	(	const unsigned int	off_L,
		const ChVectorDynamic<> &	L
	)

overridevirtual

From global reaction vector to item's reaction forces.

Parameters

off_L	offset in L vector
L	L vector of reaction forces

Reimplemented from chrono::ChPhysicsItem.

◆ IntToDescriptor()

void chrono::ChContactContainerNSC::IntToDescriptor	(	const unsigned int	off_v,
		const ChStateDelta &	v,
		const ChVectorDynamic<> &	R,
		const unsigned int	off_L,
		const ChVectorDynamic<> &	L,
		const ChVectorDynamic<> &	Qc
	)

overridevirtual

Prepare variables and constraints to accommodate a solution:

Parameters

off_v	offset for v and R
v	vector that will be copied into the q 'unknowns' term of the variables (for warm starting)
R	vector that will be copied into the F 'force' term of the variables
off_L	offset for L and Qc
L	vector that will be copied into the L 'lagrangian ' term of the constraints (for warm starting)
Qc	vector that will be copied into the Qb 'constraint' term of the constraints

Reimplemented from chrono::ChPhysicsItem.

◆ Update()

void chrono::ChContactContainerNSC::Update	(	double	mtime,
		bool	update_assets = `true`
	)

overridevirtual

Update state of this contact container: compute jacobians, violations, etc.

and store results in inner structures of contacts.

Reimplemented from chrono::ChPhysicsItem.

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

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

Description

Public Types

Public Member Functions

Protected Attributes

Additional Inherited Members

Member Function Documentation

◆ ArchiveIN()

◆ BeginAddContact()

◆ ComputeContactForces()

◆ ConstraintsFetch_react()

◆ EndAddContact()

◆ GetDOC_d()

◆ IntFromDescriptor()

◆ IntLoadConstraint_C()

◆ IntLoadResidual_CqL()

◆ IntStateGatherReactions()

◆ IntStateScatterReactions()

◆ IntToDescriptor()

◆ Update()