chrono::ChPhysicsItem Class Reference

Description

Base class for items that can contain objects of ChVariables or ChConstraints, such as rigid bodies, mechanical joints, etc.

#include <ChPhysicsItem.h>

Inheritance diagram for chrono::ChPhysicsItem:
Collaboration diagram for chrono::ChPhysicsItem:

Public Member Functions

 ChPhysicsItem (const ChPhysicsItem &other)
 
virtual ChPhysicsItemClone () const override
 "Virtual" copy constructor (covariant return type).
 
ChSystemGetSystem () 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< ChAssetGetAssetN (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 (double mytime, bool update_assets=true)
 This is an important function, which is called by the owner ChSystem at least once per integration step. More...
 
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.
 
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_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 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)
 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)
 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 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 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...
 
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::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

ChSystemsystem
 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
 

Friends

class ChSystem
 
class ChAssembly
 

Member Function Documentation

◆ ArchiveIN()

void chrono::ChPhysicsItem::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::ChObj.

Reimplemented in chrono::ChLinkMateOrthogonal, chrono::ChBody, chrono::ChLinkMateParallel, chrono::ChMatterSPH, chrono::ChLinkMateXdistance, chrono::ChParticlesClones, chrono::fea::ChMatterMeshless, chrono::fea::ChLinkPointFrameGeneric, chrono::fea::ChLinkPointTrifaceRot, chrono::ChLinkLockLock, chrono::ChLinkMateCoaxial, chrono::ChAssembly, chrono::ChShaft, chrono::ChLinkMatePlane, chrono::ChShaftsBodyTranslation, chrono::ChLinkMotorLinearDriveline, chrono::ChShaftsPlanetary, chrono::ChLinkMarkers, chrono::ChShaftsMotor, chrono::ChLinkMotorRotationDriveline, chrono::ChLinkMateGeneric, chrono::ChContactContainerNSC, chrono::fea::ChLinkPointTriface, chrono::fea::ChLinkBeamIGAslider, chrono::ChConveyor, chrono::ChLinkTSDA, chrono::ChShaftsMotorSpeed, chrono::fea::ChLinkPointFrame, chrono::ChShaftsGearboxAngled, chrono::ChLinkRevoluteTranslational, chrono::ChShaftsGearbox, chrono::ChLinkLock, chrono::ChLinkRevoluteSpherical, chrono::fea::ChLinkDirFrame, chrono::ChContactContainerSMC, chrono::ChLinkDistance, chrono::ChLinkPulley, chrono::ChShaftsClutch, chrono::ChLinkGear, chrono::ChLinkSpringCB, chrono::fea::ChLinkPointPoint, chrono::ChShaftsGear, chrono::ChLinkUniversal, chrono::ChShaftsBody, chrono::ChLinkRevolute, chrono::ChShaftsTorqueConverter, chrono::ChShaftsMotorAngle, chrono::ChProximityContainerMeshless, chrono::ChLinkMotorLinearSpeed, chrono::ChLinkMotorRotationSpeed, chrono::ChProximityContainerSPH, chrono::ChLinkRackpinion, chrono::ChLinkSpring, chrono::ChLink, chrono::ChLinkMotionImposed, chrono::ChShaftsCouple, chrono::ChLinkBase, chrono::ChLinkLinActuator, chrono::ChLinkClearance, chrono::ChBodyAuxRef, chrono::ChIndexedParticles, chrono::ChShaftsTorqueBase, chrono::ChLinkTrajectory, chrono::ChLinkMotorLinearPosition, chrono::ChLinkMotorRotationAngle, chrono::ChLinkMotorRotation, chrono::ChLoadContainer, chrono::ChShaftsMotorTorque, chrono::ChLinkRotSpringCB, chrono::ChShaftsThermalEngine, chrono::ChLinkMotorLinear, chrono::ChLinkMotorLinearForce, chrono::ChLinkMotorRotationTorque, chrono::ChLinkBrake, chrono::ChShaftsMotorBase, chrono::ChIndexedNodes, chrono::ChLinkBushing, chrono::ChShaftsTorsionSpring, chrono::ChLinkMotor, chrono::ChShaftsTorque, chrono::ChLinkPointSpline, chrono::ChLinkScrew, chrono::ChLinkMate, chrono::ChContactContainer, and chrono::ChProximityContainer.

◆ ConstraintsFetch_react()

◆ GetAssetsFrame()

virtual ChFrame chrono::ChPhysicsItem::GetAssetsFrame ( unsigned int  nclone = 0)
inlinevirtual

Get the master coordinate system for assets that have some geometric meaning.

It could be used, for example, by a visualization system to show a 3d shape of this item. Children classes might override this (for example, for a ChBody, this will return the coordinate system of the rigid body). Optional parameter 'nclone' can be used for items that contain 'clones' (ex. lot of particles with the same visualization shape), so the corresponding coordinate frame can be returned.

Reimplemented in chrono::ChBody, chrono::ChLinkMarkers, chrono::ChLinkMateGeneric, chrono::ChIndexedParticles, and chrono::ChLinkBase.

◆ GetAssetsFrameNclones()

virtual unsigned int chrono::ChPhysicsItem::GetAssetsFrameNclones ( )
inlinevirtual

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.

lot of particle with the same visualization shape). If so, returns Nclones >0 , the number of clones including the original. Then use GetAssetsFrame(n), n=0...Nclones-1, to access the corresponding coord.frame.

Reimplemented in chrono::ChIndexedParticles.

◆ GetCenter()

void chrono::ChPhysicsItem::GetCenter ( ChVector<> &  mcenter)
virtual

Get a symbolic 'center' of the object.

By default this function returns the center of the AABB. It could be overridden by child classes, anyway it must always get a point that must be inside AABB.

◆ GetCollide()

virtual bool chrono::ChPhysicsItem::GetCollide ( ) const
inlinevirtual

Tell if the object is subject to collision.

Only for interface; child classes may override this, using internal flags.

Reimplemented in chrono::ChMatterSPH, chrono::fea::ChMatterMeshless, chrono::ChParticlesClones, chrono::ChConveyor, chrono::fea::ChMesh, and chrono::ChBody.

◆ GetDOF()

virtual int chrono::ChPhysicsItem::GetDOF ( )
inlinevirtual

◆ GetDOF_w()

virtual int chrono::ChPhysicsItem::GetDOF_w ( )
inlinevirtual

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

DOF=4 for quaternions, but DOF_w = 3 for its Lie algebra, ex angular velocity) Children classes might override this.

Reimplemented in chrono::ChAssembly, chrono::ChBody, chrono::fea::ChMesh, chrono::ChConveyor, and chrono::ChIndexedParticles.

◆ GetTotalAABB()

void chrono::ChPhysicsItem::GetTotalAABB ( ChVector<> &  bbmin,
ChVector<> &  bbmax 
)
virtual

Get the entire AABB axis-aligned bounding box of the object.

The AABB must enclose the collision models, if any. By default is infinite AABB. Should be overridden by child classes.

Reimplemented in chrono::ChBody.

◆ IntFromDescriptor()

◆ IntLoadConstraint_C()

◆ IntLoadConstraint_Ct()

virtual void chrono::ChPhysicsItem::IntLoadConstraint_Ct ( const unsigned int  off,
ChVectorDynamic<> &  Qc,
const double  c 
)
inlinevirtual

◆ IntLoadResidual_CqL()

◆ IntLoadResidual_F()

◆ IntLoadResidual_Mv()

virtual void chrono::ChPhysicsItem::IntLoadResidual_Mv ( const unsigned int  off,
ChVectorDynamic<> &  R,
const ChVectorDynamic<> &  w,
const double  c 
)
inlinevirtual

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 in chrono::ChMatterSPH, chrono::fea::ChMatterMeshless, chrono::ChParticlesClones, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChLinkMotorLinearDriveline, chrono::ChLinkMotorRotationDriveline, chrono::ChShaft, chrono::ChShaftsMotorSpeed, chrono::ChConveyor, chrono::ChLinkMotorLinearSpeed, and chrono::ChLinkMotorRotationSpeed.

◆ IntStateGather()

virtual void chrono::ChPhysicsItem::IntStateGather ( const unsigned int  off_x,
ChState x,
const unsigned int  off_v,
ChStateDelta v,
double &  T 
)
inlinevirtual

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 in chrono::ChMatterSPH, chrono::fea::ChMatterMeshless, chrono::ChParticlesClones, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChLinkMotorLinearDriveline, chrono::ChLinkMotorRotationDriveline, chrono::ChShaft, chrono::ChShaftsMotorSpeed, chrono::ChConveyor, chrono::ChLinkMotorLinearSpeed, and chrono::ChLinkMotorRotationSpeed.

◆ IntStateGatherAcceleration()

virtual void chrono::ChPhysicsItem::IntStateGatherAcceleration ( const unsigned int  off_a,
ChStateDelta a 
)
inlinevirtual

◆ IntStateGatherReactions()

◆ IntStateIncrement()

virtual void chrono::ChPhysicsItem::IntStateIncrement ( const unsigned int  off_x,
ChState x_new,
const ChState x,
const unsigned int  off_v,
const ChStateDelta Dv 
)
inlinevirtual

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 in chrono::ChParticlesClones, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChLinkMotorLinearDriveline, chrono::ChLinkMotorRotationDriveline, and chrono::ChConveyor.

◆ IntStateScatter()

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

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 in chrono::ChMatterSPH, chrono::fea::ChMatterMeshless, chrono::ChParticlesClones, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChLinkMotorLinearDriveline, chrono::ChLinkMotorRotationDriveline, chrono::ChShaft, chrono::ChShaftsMotorSpeed, chrono::ChConveyor, chrono::ChLinkMotorLinearSpeed, and chrono::ChLinkMotorRotationSpeed.

◆ IntStateScatterAcceleration()

virtual void chrono::ChPhysicsItem::IntStateScatterAcceleration ( const unsigned int  off_a,
const ChStateDelta a 
)
inlinevirtual

◆ IntStateScatterReactions()

◆ IntToDescriptor()

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

◆ KRMmatricesLoad()

virtual void chrono::ChPhysicsItem::KRMmatricesLoad ( double  Kfactor,
double  Rfactor,
double  Mfactor 
)
inlinevirtual

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 in chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChContactContainerSMC, and chrono::ChLoadContainer.

◆ SetNoSpeedNoAcceleration()

virtual void chrono::ChPhysicsItem::SetNoSpeedNoAcceleration ( )
inlinevirtual

Set zero speed (and zero accelerations) in state, without changing the position.

Child classes should implement this function if GetDOF() > 0. It is used by owner ChSystem for some static analysis.

Reimplemented in chrono::ChMatterSPH, chrono::fea::ChMatterMeshless, chrono::ChParticlesClones, chrono::ChShaft, chrono::ChAssembly, chrono::ChBody, and chrono::fea::ChMesh.

◆ Update() [1/2]

virtual void chrono::ChPhysicsItem::Update ( bool  update_assets = true)
inlinevirtual

As above, but does not require updating of time-dependent data.

By default, calls Update(mytime) using item's current time.

Reimplemented in chrono::ChBody, chrono::ChMatterSPH, chrono::ChParticlesClones, chrono::fea::ChMatterMeshless, chrono::ChAssembly, chrono::ChLink, and chrono::ChBodyAuxRef.

◆ Update() [2/2]

void chrono::ChPhysicsItem::Update ( double  mytime,
bool  update_assets = true 
)
virtual

This is an important function, which is called by the owner ChSystem at least once per integration step.

It may update all auxiliary data of the item, such as matrices if any, etc., depending on the current coordinates. The inherited classes, for example the ChLinkMask, often implement specialized versions of this Update(time) function, because they might need to update inner states, forces, springs, etc. This base version, by default, simply updates the item's time, and update the asset tree, if any.

Reimplemented in chrono::ChLinkRevoluteTranslational, chrono::ChLinkRevoluteSpherical, chrono::ChLinkUniversal, chrono::ChLinkRevolute, chrono::ChBody, chrono::ChMatterSPH, chrono::ChParticlesClones, chrono::fea::ChLinkPointFrameGeneric, chrono::fea::ChMatterMeshless, chrono::fea::ChLinkPointTrifaceRot, chrono::ChShaft, chrono::ChShaftsBodyTranslation, chrono::ChShaftsPlanetary, chrono::ChShaftsMotor, chrono::ChAssembly, chrono::fea::ChLinkPointTriface, chrono::fea::ChLinkBeamIGAslider, chrono::ChConveyor, chrono::fea::ChLinkPointFrame, chrono::ChShaftsGearboxAngled, chrono::ChLinkLock, chrono::ChShaftsGearbox, chrono::fea::ChLinkDirFrame, chrono::ChLinkMarkers, chrono::ChLinkMotorLinearDriveline, chrono::ChShaftsClutch, chrono::fea::ChLinkPointPoint, chrono::ChShaftsGear, chrono::ChLinkMotorRotationDriveline, chrono::ChShaftsBody, chrono::ChShaftsTorqueConverter, chrono::ChShaftsMotorSpeed, chrono::ChShaftsMotorAngle, chrono::ChLink, chrono::ChShaftsTorqueBase, chrono::ChLinkMotorLinearSpeed, chrono::ChLinkMotorRotationSpeed, chrono::ChShaftsMotorTorque, chrono::ChLoadContainer, chrono::ChLinkMotionImposed, chrono::ChLinkMotorRotation, chrono::ChLinkMotorLinearPosition, chrono::ChLinkMotorRotationAngle, chrono::ChLinkMotorLinear, chrono::ChLinkMotor, chrono::ChLinkMotorLinearForce, chrono::ChLinkMotorRotationTorque, chrono::ChLinkMateOrthogonal, chrono::ChLinkMateXdistance, chrono::ChLinkMatePlane, chrono::ChContactContainerNSC, chrono::ChLinkMateGeneric, chrono::ChContactContainerSMC, chrono::ChLinkDistance, and chrono::fea::ChMesh.

◆ VariablesFbIncrementMq()

virtual void chrono::ChPhysicsItem::VariablesFbIncrementMq ( )
inlinevirtual

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 in chrono::ChMatterSPH, chrono::fea::ChMatterMeshless, chrono::ChParticlesClones, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChLinkMotorLinearDriveline, chrono::ChLinkMotorRotationDriveline, chrono::ChShaft, chrono::ChShaftsMotorSpeed, chrono::ChConveyor, chrono::ChLinkMotorLinearSpeed, and chrono::ChLinkMotorRotationSpeed.

◆ VariablesQbIncrementPosition()

virtual void chrono::ChPhysicsItem::VariablesQbIncrementPosition ( double  step)
inlinevirtual

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 in chrono::ChMatterSPH, chrono::fea::ChMatterMeshless, chrono::ChParticlesClones, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChLinkMotorLinearDriveline, chrono::ChLinkMotorRotationDriveline, chrono::ChShaft, and chrono::ChConveyor.

◆ VariablesQbLoadSpeed()

virtual void chrono::ChPhysicsItem::VariablesQbLoadSpeed ( )
inlinevirtual

◆ VariablesQbSetSpeed()

virtual void chrono::ChPhysicsItem::VariablesQbSetSpeed ( double  step = 0)
inlinevirtual

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 in chrono::ChMatterSPH, chrono::fea::ChMatterMeshless, chrono::ChParticlesClones, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChLinkMotorLinearDriveline, chrono::ChLinkMotorRotationDriveline, chrono::ChShaft, chrono::ChShaftsMotorSpeed, chrono::ChConveyor, chrono::ChLinkMotorLinearSpeed, and chrono::ChLinkMotorRotationSpeed.


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