Description

Class for assemblies of physical items.

This class is a container of ChPhysicsItems items i.e. rigid bodies, shafts, links, etc. ChAssembly objects can also contain other ChAssembly objects. Location and rotation of the contained ChPhysicsItems are assumed to be expressed with respect to the absolute frame.

#include <ChAssembly.h>

Inheritance diagram for chrono::ChAssembly:
Collaboration diagram for chrono::ChAssembly:

Public Member Functions

 ChAssembly (const ChAssembly &other)
 
virtual ChAssemblyClone () const override
 "Virtual" copy constructor (covariant return type).
 
ChAssemblyoperator= (ChAssembly other)
 Assignment operator for ChAssembly.
 
void Clear ()
 Removes all inserted items: bodies, links, etc.
 
void AddBody (std::shared_ptr< ChBody > body)
 Attach a body to this assembly.
 
void AddShaft (std::shared_ptr< ChShaft > shaft)
 Attach a shaft to this assembly.
 
void AddLink (std::shared_ptr< ChLinkBase > link)
 Attach a link to this assembly.
 
void AddMesh (std::shared_ptr< fea::ChMesh > mesh)
 Attach a mesh to this assembly.
 
void AddOtherPhysicsItem (std::shared_ptr< ChPhysicsItem > item)
 Attach a ChPhysicsItem object that is not a body, link, or mesh.
 
void Add (std::shared_ptr< ChPhysicsItem > item)
 Attach an arbitrary ChPhysicsItem (e.g. More...
 
void AddBatch (std::shared_ptr< ChPhysicsItem > item)
 Items added in this way are added like in the Add() method, but not instantly, they are simply queued in a batch of 'to add' items, that are added automatically at the first Setup() call. More...
 
void FlushBatch ()
 If some items are queued for addition in the assembly, using AddBatch(), this will effectively add them and clean the batch. More...
 
void RemoveBody (std::shared_ptr< ChBody > body)
 Remove a body from this assembly.
 
void RemoveShaft (std::shared_ptr< ChShaft > shaft)
 Remove a shaft from this assembly.
 
void RemoveLink (std::shared_ptr< ChLinkBase > link)
 Remove a link from this assembly.
 
void RemoveMesh (std::shared_ptr< fea::ChMesh > mesh)
 Remove a mesh from the assembly.
 
void RemoveOtherPhysicsItem (std::shared_ptr< ChPhysicsItem > item)
 Remove a ChPhysicsItem object that is not a body or a link.
 
void Remove (std::shared_ptr< ChPhysicsItem > item)
 Remove arbitrary ChPhysicsItem that was added to the assembly.
 
void RemoveAllBodies ()
 Remove all bodies from this assembly.
 
void RemoveAllShafts ()
 Remove all shafts from this assembly.
 
void RemoveAllLinks ()
 Remove all links from this assembly.
 
void RemoveAllMeshes ()
 Remove all meshes from this assembly.
 
void RemoveAllOtherPhysicsItems ()
 Remove all physics items not in the body, link, or mesh lists.
 
const std::vector< std::shared_ptr< ChBody > > & GetBodies () const
 Get the list of bodies.
 
const std::vector< std::shared_ptr< ChShaft > > & GetShafts () const
 Get the list of shafts.
 
const std::vector< std::shared_ptr< ChLinkBase > > & GetLinks () const
 Get the list of links.
 
const std::vector< std::shared_ptr< fea::ChMesh > > & GetMeshes () const
 Get the list of meshes.
 
const std::vector< std::shared_ptr< ChPhysicsItem > > & GetOtherPhysicsItems () const
 Get the list of physics items that are not in the body or link lists.
 
std::shared_ptr< ChBodySearchBody (const std::string &name) const
 Search a body by its name.
 
std::shared_ptr< ChBodySearchBodyID (int id) const
 Search a body by its ID.
 
std::shared_ptr< ChShaftSearchShaft (const std::string &name) const
 Search a shaft by its name.
 
std::shared_ptr< ChLinkBaseSearchLink (const std::string &name) const
 Search a link by its name.
 
std::shared_ptr< fea::ChMeshSearchMesh (const std::string &name) const
 Search a mesh by its name.
 
std::shared_ptr< ChPhysicsItemSearchOtherPhysicsItem (const std::string &name) const
 Search from other ChPhysics items (not bodies, links, or meshes) by name.
 
std::shared_ptr< ChMarkerSearchMarker (const std::string &name) const
 Search a marker by its name.
 
std::shared_ptr< ChMarkerSearchMarker (int id) const
 Search a marker by its unique ID.
 
std::shared_ptr< ChPhysicsItemSearch (const std::string &name) const
 Search an item (body, link or other ChPhysics items) by name.
 
unsigned int GetNumBodies () const
 Get the total number of bodies added to the assembly, including fixed and sleeping bodies.
 
unsigned int GetNumBodiesActive () const
 Get the number of active bodies, excluding sleeping or fixed.
 
unsigned int GetNumBodiesSleeping () const
 Get the number of sleeping bodies.
 
unsigned int GetNumBodiesFixed () const
 Get the number of bodies fixed to ground.
 
unsigned int GetNumShafts () const
 Get the number of shafts.
 
unsigned int GetNumShaftsSleeping () const
 Get the number of shafts that are in sleeping mode (excluding fixed shafts).
 
unsigned int GetNumShaftsFixed () const
 Get the number of shafts that are fixed to ground.
 
unsigned int GetNumShaftsTotal () const
 Get the total number of shafts added to the assembly, including the grounded and sleeping shafts.
 
unsigned int GetNumLinks () const
 Get the number of links (including non active).
 
unsigned int GetNumLinksActive () const
 Get the number of active links.
 
unsigned int GetNumMeshes () const
 Get the number of meshes.
 
unsigned int GetNumOtherPhysicsItems () const
 Get the number of other active physics items (including non active).
 
unsigned int GetNumOtherPhysicsItemsActive () const
 Get the number of other active physics items.
 
virtual unsigned int GetNumCoordsPosLevel () override
 Get the number of scalar coordinates at the position level. More...
 
virtual unsigned int GetNumCoordsVelLevel () override
 Get the number of scalar coordinates at the velocity level.
 
virtual unsigned int GetNumConstraints () override
 Get the number of scalar constraints in the assembly.
 
virtual unsigned int GetNumConstraintsBilateral () override
 Get the number of scalar bilateral constraints in the assembly.
 
virtual unsigned int GetNumConstraintsUnilateral () override
 Get the number of scalar unilateral constraints in the assembly.
 
virtual void SetSystem (ChSystem *m_system) override
 Set the pointer to the parent ChSystem() and also add to new collision system / remove from old coll.system.
 
virtual void AddCollisionModelsToSystem (ChCollisionSystem *coll_sys) const override
 Add collision models (if any) for all items in the assembly to the provided collision system.
 
virtual void RemoveCollisionModelsFromSystem (ChCollisionSystem *coll_sys) const override
 Remove the collision models (if any) for all items in the assembly from the provided collision system.
 
virtual void SyncCollisionModels () override
 Synchronize collision models for all physics items in this assembly.
 
virtual void Setup () override
 Counts the number of bodies, links, and meshes. More...
 
virtual void Update (double mytime, bool update_assets=true) override
 Updates all the auxiliary data and children of bodies, forces, links, given their current state.
 
virtual void Update (bool update_assets=true) override
 Updates all the auxiliary data and children of bodies, forces, links, given their current state.
 
virtual void ForceToRest () override
 Set zero speed (and zero accelerations) in state, without changing the position.
 
virtual void IntStateGather (const unsigned int off_x, ChState &x, const unsigned int off_v, ChStateDelta &v, double &T) override
 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) override
 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) override
 From item's state acceleration to global acceleration vector. More...
 
virtual void IntStateScatterAcceleration (const unsigned int off_a, const ChStateDelta &a) override
 From global acceleration vector to item's state acceleration. More...
 
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 IntStateIncrement (const unsigned int off_x, ChState &x_new, const ChState &x, const unsigned int off_v, const ChStateDelta &Dv) override
 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) override
 Computes Dt = x_new - x, using vectors at specified offsets. More...
 
virtual void IntLoadResidual_F (const unsigned int off, ChVectorDynamic<> &R, const double c) override
 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) override
 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) override
 Adds the lumped mass to a Md vector, representing a mass diagonal matrix. 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 += c*Cq'*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 IntLoadConstraint_Ct (const unsigned int off, ChVectorDynamic<> &Qc, const double c) override
 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) 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 InjectVariables (ChSystemDescriptor &descriptor) override
 Register with the given system descriptor any ChVariable objects associated with this item.
 
virtual void InjectConstraints (ChSystemDescriptor &descriptor) override
 Register with the given system descriptor any ChConstraint objects associated with this item.
 
virtual void LoadConstraintJacobians () override
 Compute and load current Jacobians in encapsulated ChConstraint objects.
 
virtual void InjectKRMMatrices (ChSystemDescriptor &descriptor) override
 Register with the given system descriptor any ChKRMBlock objects associated with this item.
 
virtual void LoadKRMMatrices (double Kfactor, double Rfactor, double Mfactor) override
 Compute and load current stiffnes (K), damping (R), and mass (M) matrices in encapsulated ChKRMBlock objects. More...
 
virtual void VariablesFbReset () override
 Sets the 'fb' part (the known term) of the encapsulated ChVariables to zero.
 
virtual void VariablesFbLoadForces (double factor=1) override
 Adds the current forces (applied to item) into the encapsulated ChVariables, in the 'fb' part: qf+=forces*factor.
 
virtual void VariablesQbLoadSpeed () override
 Initialize the 'qb' part of the ChVariables with the current value of speeds. More...
 
virtual void VariablesFbIncrementMq () override
 Adds M*q (masses multiplied current 'qb') to Fb, ex. More...
 
virtual void VariablesQbSetSpeed (double step=0) override
 Fetches the item speed (ex. More...
 
virtual void VariablesQbIncrementPosition (double step) override
 Increment item positions by the 'qb' part of the ChVariables, multiplied by a 'step' factor. More...
 
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 ConstraintsBiLoad_Ct (double factor=1) override
 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) override
 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) override
 Adds the current link-forces, if any, (caused by springs, etc.) to the 'fb' vectors of the ChVariables referenced by encapsulated ChConstraints.
 
virtual void ConstraintsFetch_react (double factor=1) override
 Fetches the reactions from the lagrangian multiplier (l_i) of encapsulated ChConstraints. More...
 
void ShowHierarchy (std::ostream &outstream, int level=0) const
 Writes the hierarchy of contained bodies, markers, 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.
 
- Public Member Functions inherited from chrono::ChPhysicsItem
 ChPhysicsItem (const ChPhysicsItem &other)
 
ChSystemGetSystem () const
 Get the pointer to the parent ChSystem().
 
void AddVisualModel (std::shared_ptr< ChVisualModel > model)
 Add an (optional) visualization model. More...
 
std::shared_ptr< ChVisualModelGetVisualModel () 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< ChVisualShapeGetVisualShape (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< ChVisualShapeFEAGetVisualShapeFEA (unsigned int i) const
 Access the specified FEA visualization object in the visualization model (if any). More...
 
virtual ChFrame GetVisualModelFrame (unsigned int nclone=0) const
 Get the reference frame (expressed in and relative to the absolute frame) of the visual model. 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 IsActive () const
 Return true if the object is active and included in dynamics.
 
virtual bool IsCollisionEnabled () const
 Tell if the object is subject to collision. More...
 
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...
 
void UpdateVisualModel ()
 Utility function to update only the associated visual assets (if any).
 
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.
 
- 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 ()
 

Protected Member Functions

virtual void SetupInitial () override
 
- Protected Member Functions inherited from chrono::ChObj
int GenerateUniqueIdentifier ()
 

Protected Attributes

std::vector< std::shared_ptr< ChBody > > bodylist
 list of rigid bodies
 
std::vector< std::shared_ptr< ChShaft > > shaftlist
 list of 1-D shafts
 
std::vector< std::shared_ptr< ChLinkBase > > linklist
 list of joints (links)
 
std::vector< std::shared_ptr< fea::ChMesh > > meshlist
 list of meshes
 
std::vector< std::shared_ptr< ChPhysicsItem > > otherphysicslist
 list of other physics objects
 
std::vector< std::shared_ptr< ChPhysicsItem > > batch_to_insert
 list of items to insert at once
 
unsigned int m_num_bodies_active
 number of active bodies
 
unsigned int m_num_bodies_sleep
 number of sleeping bodies
 
unsigned int m_num_bodies_fixed
 number of fixed bodies
 
unsigned int m_num_shafts
 number of active shafts
 
unsigned int m_num_shafts_sleep
 number of sleeping shafts
 
unsigned int m_num_shafts_fixed
 number of fixed shafts
 
unsigned int m_num_links_active
 number of active links
 
unsigned int m_num_meshes
 number of meshes
 
unsigned int m_num_otherphysicsitems_active
 number of other active physics items
 
unsigned int m_num_coords_pos
 number of scalar position-level coordinates for all active bodies
 
unsigned int m_num_coords_vel
 number of scalar velocity-level coordinates for all active bodies
 
unsigned int m_num_constr
 number of scalar constraints
 
unsigned int m_num_constr_bil
 number of scalar bilateral constraints
 
unsigned int m_num_constr_uni
 number of scalar unilateral constraints
 
- Protected Attributes inherited from chrono::ChPhysicsItem
ChSystemsystem
 parent system
 
std::shared_ptr< ChVisualModelInstancevis_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
 

Friends

class ChSystem
 
class ChSystemMulticore
 
ChApi void swap (ChAssembly &first, ChAssembly &second)
 Swap the contents of the two provided ChAssembly objects. More...
 

Member Function Documentation

◆ Add()

void chrono::ChAssembly::Add ( std::shared_ptr< ChPhysicsItem item)

Attach an arbitrary ChPhysicsItem (e.g.

ChBody, ChParticles, ChLink, etc.) to the assembly. It will take care of adding it to the proper list of bodies, links, meshes, or generic physic item. (i.e. it calls AddBody(), AddShaft(), AddLink(), AddMesh(), or AddOtherPhysicsItem()). Note, you cannot call Add() during an Update (i.e. items like particle generators that are already inserted in the assembly cannot call this) because not thread safe; instead, use AddBatch().

◆ AddBatch()

void chrono::ChAssembly::AddBatch ( std::shared_ptr< ChPhysicsItem item)

Items added in this way are added like in the Add() method, but not instantly, they are simply queued in a batch of 'to add' items, that are added automatically at the first Setup() call.

This is thread safe.

◆ ConstraintsFetch_react()

void chrono::ChAssembly::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.

◆ FlushBatch()

void chrono::ChAssembly::FlushBatch ( )

If some items are queued for addition in the assembly, using AddBatch(), this will effectively add them and clean the batch.

Called automatically at each Setup().

◆ GetNumCoordsPosLevel()

virtual unsigned int chrono::ChAssembly::GetNumCoordsPosLevel ( )
inlineoverridevirtual

Get the number of scalar coordinates at the position level.

This count includes the 4th dimension of quaternions (if any), thus potentially differing from GetNumCoordsVelLevel().

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ IntFromDescriptor()

void chrono::ChAssembly::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_voffset for v
vvector to where the q 'unknowns' term of the variables will be copied
off_Loffset for L
Lvector to where L 'lagrangian ' term of the constraints will be copied

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ IntLoadConstraint_C()

void chrono::ChAssembly::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
offoffset in Qc residual
Qcresult: the Qc residual, Qc += c*C
ca scaling factor
do_clampapply clamping to c*C?
recovery_clampvalue for min/max clamping of c*C

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ IntLoadConstraint_Ct()

void chrono::ChAssembly::IntLoadConstraint_Ct ( const unsigned int  off,
ChVectorDynamic<> &  Qc,
const double  c 
)
overridevirtual

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

Parameters
offoffset in Qc residual
Qcresult: the Qc residual, Qc += c*Ct
ca scaling factor

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ IntLoadLumpedMass_Md()

void chrono::ChAssembly::IntLoadLumpedMass_Md ( const unsigned int  off,
ChVectorDynamic<> &  Md,
double &  err,
const double  c 
)
overridevirtual

Adds the lumped mass to a Md vector, representing a mass diagonal matrix.

Used by lumped explicit integrators. If mass lumping is impossible or approximate, adds scalar error to "error" parameter. Md += c*diag(M)

Parameters
offoffset in Md vector
Mdresult: Md vector, diagonal of the lumped mass matrix
errresult: not touched if lumping does not introduce errors
ca scaling factor

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ IntLoadResidual_CqL()

void chrono::ChAssembly::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_Loffset in L multipliers
Rresult: the R residual, R += c*Cq'*L
Lthe L vector
ca scaling factor

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ IntLoadResidual_F()

void chrono::ChAssembly::IntLoadResidual_F ( const unsigned int  off,
ChVectorDynamic<> &  R,
const double  c 
)
overridevirtual

Takes the F force term, scale and adds to R at given offset: R += c*F.

Parameters
offoffset in R residual
Rresult: the R residual, R += c*F
ca scaling factor

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ IntLoadResidual_Mv()

void chrono::ChAssembly::IntLoadResidual_Mv ( const unsigned int  off,
ChVectorDynamic<> &  R,
const ChVectorDynamic<> &  w,
const double  c 
)
overridevirtual

Takes the M*v term, multiplying mass by a vector, scale and adds to R at given offset: R += c*M*w.

Parameters
offoffset in R residual
Rresult: the R residual, R += c*M*v
wthe w vector
ca scaling factor

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ IntStateGather()

void chrono::ChAssembly::IntStateGather ( const unsigned int  off_x,
ChState x,
const unsigned int  off_v,
ChStateDelta v,
double &  T 
)
overridevirtual

From item's state to global state vectors y={x,v} pasting the states at the specified offsets.

Parameters
off_xoffset in x state vector
xstate vector, position part
off_voffset in v state vector
vstate vector, speed part
Ttime

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ IntStateGatherAcceleration()

void chrono::ChAssembly::IntStateGatherAcceleration ( const unsigned int  off_a,
ChStateDelta a 
)
overridevirtual

From item's state acceleration to global acceleration vector.

Parameters
off_aoffset in a accel. vector
aacceleration part of state vector derivative

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ IntStateGatherReactions()

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

From item's reaction forces to global reaction vector.

Parameters
off_Loffset in L vector
LL vector of reaction forces

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ IntStateGetIncrement()

void chrono::ChAssembly::IntStateGetIncrement ( const unsigned int  off_x,
const ChState x_new,
const ChState x,
const unsigned int  off_v,
ChStateDelta Dv 
)
overridevirtual

Computes Dt = x_new - x, using vectors at specified offsets.

By default, when DOF = DOF_w, it does just the difference of two state vectors, but in some cases (ex when using quaternions for rotations) it could do more complex stuff, and children classes might overload it.

Parameters
off_xoffset in x state vector
x_newstate vector, final position part
xstate vector, initial position part
off_voffset in v state vector
Dvstate vector, increment. Here gets the result

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ IntStateIncrement()

void chrono::ChAssembly::IntStateIncrement ( const unsigned int  off_x,
ChState x_new,
const ChState x,
const unsigned int  off_v,
const ChStateDelta Dv 
)
overridevirtual

Computes x_new = x + Dt , using vectors at specified offsets.

By default, when DOF = DOF_w, it does just the sum, but in some cases (ex when using quaternions for rotations) it could do more complex stuff, and children classes might overload it.

Parameters
off_xoffset in x state vector
x_newstate vector, position part, incremented result
xstate vector, initial position part
off_voffset in v state vector
Dvstate vector, increment

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ IntStateScatter()

void chrono::ChAssembly::IntStateScatter ( const unsigned int  off_x,
const ChState x,
const unsigned int  off_v,
const ChStateDelta v,
const double  T,
bool  full_update 
)
overridevirtual

From global state vectors y={x,v} to item's state (and update) fetching the states at the specified offsets.

Parameters
off_xoffset in x state vector
xstate vector, position part
off_voffset in v state vector
vstate vector, speed part
Ttime
full_updateperform complete update

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ IntStateScatterAcceleration()

void chrono::ChAssembly::IntStateScatterAcceleration ( const unsigned int  off_a,
const ChStateDelta a 
)
overridevirtual

From global acceleration vector to item's state acceleration.

Parameters
off_aoffset in a accel. vector
aacceleration part of state vector derivative

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ IntStateScatterReactions()

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

From global reaction vector to item's reaction forces.

Parameters
off_Loffset in L vector
LL vector of reaction forces

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ IntToDescriptor()

void chrono::ChAssembly::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_voffset for v and R
vvector copied into the q 'unknowns' term of the variables
Rvector copied into the F 'force' term of the variables
off_Loffset for L and Qc
Lvector copied into the L 'lagrangian ' term of the constraints
Qcvector copied into the Qb 'constraint' term of the constraints

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ LoadKRMMatrices()

void chrono::ChAssembly::LoadKRMMatrices ( double  Kfactor,
double  Rfactor,
double  Mfactor 
)
overridevirtual

Compute and load current stiffnes (K), damping (R), and mass (M) matrices in encapsulated ChKRMBlock objects.

The resulting KRM blocks represent linear combinations of the K, R, and M matrices, with the specified coefficients Kfactor, Rfactor,and Mfactor, respectively. Note: signs are flipped from the term dF/dx in the integrator: K = -dF/dq and R = -dF/dv.

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ Setup()

void chrono::ChAssembly::Setup ( )
overridevirtual

Counts the number of bodies, links, and meshes.

Computes the offsets of object states in the global state. Assumes that this->offset_x this->offset_w this->offset_L are already set as starting point for offsetting all the contained sub objects.

Reimplemented from chrono::ChPhysicsItem.

Reimplemented in chrono::modal::ChModalAssembly.

◆ ShowHierarchy()

void chrono::ChAssembly::ShowHierarchy ( std::ostream &  outstream,
int  level = 0 
) const

Writes the hierarchy of contained bodies, markers, etc.

in ASCII readable form, mostly for debugging purposes. Level is the tab spacing at the left.

◆ VariablesFbIncrementMq()

void chrono::ChAssembly::VariablesFbIncrementMq ( )
overridevirtual

Adds M*q (masses multiplied current 'qb') to Fb, ex.

if qb is initialized with v_old using VariablesQbLoadSpeed, this method can be used in timestepping schemes that do: M*v_new = M*v_old + forces*dt

Reimplemented from chrono::ChPhysicsItem.

◆ VariablesQbIncrementPosition()

void chrono::ChAssembly::VariablesQbIncrementPosition ( double  step)
overridevirtual

Increment item positions by the 'qb' part of the ChVariables, multiplied by a 'step' factor.

pos+=qb*step If qb is a speed, this behaves like a single step of 1-st order numerical integration (Euler integration).

Reimplemented from chrono::ChPhysicsItem.

◆ VariablesQbLoadSpeed()

void chrono::ChAssembly::VariablesQbLoadSpeed ( )
overridevirtual

Initialize the 'qb' part of the ChVariables with the current value of speeds.

Note: since 'qb' is the unknown, this function seems unnecessary, unless used before VariablesFbIncrementMq()

Reimplemented from chrono::ChPhysicsItem.

◆ VariablesQbSetSpeed()

void chrono::ChAssembly::VariablesQbSetSpeed ( double  step = 0)
overridevirtual

Fetches the item speed (ex.

linear and angular vel.in rigid bodies) from the 'qb' part of the ChVariables and sets it as the current item speed. If 'step' is not 0, also should compute the approximate acceleration of the item using backward differences, that is accel=(new_speed-old_speed)/step. Mostly used after the solver provided the solution in ChVariables.

Reimplemented from chrono::ChPhysicsItem.

Friends And Related Function Documentation

◆ swap

ChApi void swap ( ChAssembly first,
ChAssembly second 
)
friend

Swap the contents of the two provided ChAssembly objects.

Implemented as a friend (as opposed to a member function) so classes with a ChAssembly member can use ADL when implementing their own swap.


The documentation for this class was generated from the following files:
  • /builds/uwsbel/chrono/src/chrono/physics/ChAssembly.h
  • /builds/uwsbel/chrono/src/chrono/physics/ChAssembly.cpp