Description

Class for assemblies of items, for example ChBody, ChLink, ChMesh, etc.

Note that an assembly can be added to another assembly, to create a tree-like hierarchy. All positions of rigid bodies, FEA nodes, etc. are assumed 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 > > & Get_bodylist () const
 Get the list of bodies.
 
const std::vector< std::shared_ptr< ChShaft > > & Get_shaftlist () const
 Get the list of shafts.
 
const std::vector< std::shared_ptr< ChLinkBase > > & Get_linklist () const
 Get the list of links.
 
const std::vector< std::shared_ptr< fea::ChMesh > > & Get_meshlist () const
 Get the list of meshes.
 
const std::vector< std::shared_ptr< ChPhysicsItem > > & Get_otherphysicslist () const
 Get the list of physics items that are not in the body or link lists.
 
std::shared_ptr< ChBodySearchBody (const char *name)
 Search a body by its name.
 
std::shared_ptr< ChBodySearchBodyID (int bodyID)
 Search a body by its ID.
 
std::shared_ptr< ChShaftSearchShaft (const char *name)
 Search a shaft by its name.
 
std::shared_ptr< ChLinkBaseSearchLink (const char *name)
 Search a link by its name.
 
std::shared_ptr< fea::ChMeshSearchMesh (const char *name)
 Search a mesh by its name.
 
std::shared_ptr< ChPhysicsItemSearchOtherPhysicsItem (const char *name)
 Search from other ChPhysics items (not bodies, links, or meshes) by name.
 
std::shared_ptr< ChMarkerSearchMarker (const char *name)
 Search a marker by its name.
 
std::shared_ptr< ChMarkerSearchMarker (int markID)
 Search a marker by its unique ID.
 
std::shared_ptr< ChPhysicsItemSearch (const char *name)
 Search an item (body, link or other ChPhysics items) by name.
 
int GetNbodies () const
 Get the number of active bodies (so, excluding those that are sleeping or are fixed to ground).
 
int GetNbodiesSleeping () const
 Get the number of bodies that are in sleeping mode (excluding fixed bodies).
 
int GetNbodiesFixed () const
 Get the number of bodies that are fixed to ground.
 
int GetNbodiesTotal () const
 Get the total number of bodies added to the assembly, including the grounded and sleeping bodies.
 
int GetNshafts () const
 Get the number of shafts.
 
int GetNshaftsSleeping () const
 Get the number of shafts that are in sleeping mode (excluding fixed shafts).
 
int GetNshaftsFixed () const
 Get the number of shafts that are fixed to ground.
 
int GetNshaftsTotal () const
 Get the total number of shafts added to the assembly, including the grounded and sleeping shafts.
 
int GetNlinks () const
 Get the number of links.
 
int GetNmeshes () const
 Get the number of meshes.
 
int GetNphysicsItems () const
 Get the number of other physics items (other than bodies, links, or meshes).
 
int GetNcoords () const
 Get the number of coordinates (considering 7 coords for rigid bodies because of the 4 dof of quaternions).
 
int GetNdof () const
 Get the number of degrees of freedom of the assembly.
 
int GetNdoc () const
 Get the number of scalar constraints added to the assembly, including constraints on quaternion norms.
 
int GetNsysvars () const
 Get the number of system variables (coordinates plus the constraint multipliers, in case of quaternions).
 
int GetNcoords_w () const
 Get the number of coordinates (considering 6 coords for rigid bodies, 3 transl.+3rot.)
 
int GetNdoc_w () const
 Get the number of scalar constraints added to the assembly.
 
int GetNdoc_w_C () const
 Get the number of scalar constraints added to the assembly (only bilaterals).
 
int GetNdoc_w_D () const
 Get the number of scalar constraints added to the assembly (only unilaterals).
 
int GetNsysvars_w () const
 Get the number of system variables (coordinates plus the constraint multipliers).
 
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 SyncCollisionModels () override
 If this physical item contains one or more collision models, synchronize their coordinates and bounding boxes to the state of the item.
 
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 SetNoSpeedNoAcceleration () override
 Set zero speed (and zero accelerations) in state, without changing the position.
 
virtual int GetDOF () override
 Get the number of scalar coordinates (ex. dim of position vector)
 
virtual int GetDOF_w () override
 Get the number of scalar coordinates of variables derivatives (ex. dim of speed vector)
 
virtual int GetDOC () override
 Get the number of scalar constraints, if any, in this item.
 
virtual int GetDOC_c () override
 Get the number of scalar constraints, if any, in this item (only bilateral constr.)
 
virtual int GetDOC_d () override
 Get the number of scalar constraints, if any, in this item (only unilateral constr.)
 
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 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 &mdescriptor) override
 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) 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 ConstraintsLoadJacobians () override
 Adds the current jacobians in encapsulated ChConstraints.
 
virtual void InjectKRMmatrices (ChSystemDescriptor &mdescriptor) override
 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) override
 Adds the current stiffness K and damping R and mass M matrices in encapsulated ChKblock item(s), if any. 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 (ChStreamOutAscii &m_file, int level=0) const
 Writes the hierarchy of contained bodies, markers, etc. 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 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)
 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 GetCollide () const
 Tell if the object is subject to collision. More...
 
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.
 
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
 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 SetupInitial () override
 

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
 
int nbodies
 number of bodies (currently active)
 
int nbodies_sleep
 number of bodies that are sleeping
 
int nbodies_fixed
 number of bodies that are fixed
 
int nshafts
 number of shafts (currently active)
 
int nshafts_sleep
 number of shafts that are sleeping
 
int nshafts_fixed
 number of shafts that are fixed
 
int nlinks
 number of links
 
int nmeshes
 number of meshes
 
int nphysicsitems
 number of other physics items
 
int ncoords
 number of scalar coordinates (including 4th dimension of quaternions) for all active bodies
 
int ndoc
 number of scalar constraints (including constr. on quaternions)
 
int nsysvars
 number of variables (coords+lagrangian mult.), i.e. = ncoords+ndoc for all active bodies
 
int ncoords_w
 number of scalar coordinates when using 3 rot. dof. per body; for all active bodies
 
int ndoc_w
 number of scalar constraints when using 3 rot. dof. per body; for all active bodies
 
int nsysvars_w
 number of variables when using 3 rot. dof. per body; i.e. = ncoords_w+ndoc_w
 
int ndof
 number of degrees of freedom, = ncoords-ndoc = ncoords_w-ndoc_w ,
 
int ndoc_w_C
 number of scalar constraints C, when using 3 rot. dof. per body (excluding unilaterals)
 
int ndoc_w_D
 number of scalar constraints D, when using 3 rot. dof. per body (only unilaterals)
 
- 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
 the time of simulation for the object
 

Friends

class ChSystem
 
class ChSystemMulticore
 
class ChSystemDistributed
 
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().

◆ 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.

◆ 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.

◆ KRMmatricesLoad()

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

Adds the current stiffness K and damping R and mass M matrices in encapsulated ChKblock item(s), if any.

The K, R, M matrices are added with scaling values Kfactor, Rfactor, Mfactor. NOTE: signs are flipped respect to the ChTimestepper dF/dx terms: K = -dF/dq, 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 ( ChStreamOutAscii m_file,
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 (Eulero 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

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