chrono::ChLinkSpringCB Class Reference

Description

Class for spring-damper systems with the force specified through a callback object.

#include <ChLinkSpringCB.h>

Inheritance diagram for chrono::ChLinkSpringCB:
Collaboration diagram for chrono::ChLinkSpringCB:

Public Member Functions

 ChLinkSpringCB (const ChLinkSpringCB &other)
 
virtual ChLinkSpringCBClone () const override
 "Virtual" copy constructor (covariant return type).
 
double Get_SpringRestLength () const
 
double Get_SpringDeform () const
 
double Get_SpringLength () const
 
double Get_SpringVelocity () const
 
double Get_SpringReact () const
 
void Set_SpringRestLength (double len)
 
void Set_SpringCallback (ChSpringForceCallback *force)
 
void Initialize (std::shared_ptr< ChBody > body1, std::shared_ptr< ChBody > body2, bool pos_are_relative, ChVector<> pos1, ChVector<> pos2, bool auto_rest_length=true, double rest_length=0)
 Specialized initialization for springs, given the two bodies to be connected, the positions of the two anchor endpoints of the spring (each expressed in body or abs. More...
 
ChVector GetEndPoint1Rel ()
 Get the 1st spring endpoint (expressed in Body1 coordinate system)
 
void SetEndPoint1Rel (const ChVector<> &mset)
 Set the 1st spring endpoint (expressed in Body1 coordinate system)
 
ChVector GetEndPoint1Abs ()
 Get the 1st spring endpoint (expressed in absolute coordinate system)
 
void SetEndPoint1Abs (ChVector<> &mset)
 Set the 1st spring endpoint (expressed in absolute coordinate system)
 
ChVector GetEndPoint2Rel ()
 Get the 2nd spring endpoint (expressed in Body2 coordinate system)
 
void SetEndPoint2Rel (const ChVector<> &mset)
 Set the 2nd spring endpoint (expressed in Body2 coordinate system)
 
ChVector GetEndPoint2Abs ()
 Get the 1st spring endpoint (expressed in absolute coordinate system)
 
void SetEndPoint2Abs (ChVector<> &mset)
 Set the 1st spring endpoint (expressed in absolute coordinate system)
 
virtual void UpdateForces (double time) override
 Inherits, then also adds the spring custom forces to the C_force and C_torque.
 
virtual void ArchiveOUT (ChArchiveOut &marchive) override
 Method to allow serialization of transient data to archives.
 
virtual void ArchiveIN (ChArchiveIn &marchive) override
 Method to allow deserialization of transient data from archives. More...
 
- Public Member Functions inherited from chrono::ChPhysicsItem
 ChPhysicsItem (const ChPhysicsItem &other)
 
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 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, sinchronize their coordinates and bounding boxes to the state of the item. More...
 
virtual void AddCollisionModelsToSystem ()
 If this physical item contains one or more collision models, add them to the system's collision engine. More...
 
virtual void RemoveCollisionModelsFromSystem ()
 If this physical item contains one or more collision models, remove them from the system's collision engine. More...
 
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. More...
 
virtual void StreamOUTstate (ChStreamOutBinary &mstream)
 Method to serialize only the state (position, speed) Must be implemented by child classes. More...
 
virtual void Setup ()
 This might recompute the number of coordinates, DOFs, constraints, in case this might change (ex in ChAssembly), as well as state offsets of contained items (ex in ChMesh)
 
virtual void SetNoSpeedNoAcceleration ()
 Set zero speed (and zero accelerations) in state, without changing the position. More...
 
virtual int GetDOF ()
 Get the number of scalar coordinates (variables), if any, in this item. More...
 
virtual int GetDOF_w ()
 Get the number of scalar coordinates of variables derivatives (usually = DOF, but might be different than DOF, ex. More...
 
virtual int GetDOC ()
 Get the number of scalar constraints, if any, in this item.
 
virtual int GetDOC_c ()
 Get the number of scalar constraints, if any, in this item (only bilateral constr.) Children classes might override this. More...
 
virtual int GetDOC_d ()
 Get the number of scalar constraints, if any, in this item (only unilateral constr.) Children classes might override this. More...
 
unsigned int GetOffset_x ()
 Get offset in the state vector (position part)
 
unsigned int GetOffset_w ()
 Get offset in the state vector (speed part)
 
unsigned int GetOffset_L ()
 Get offset in the lagrangian multipliers.
 
void SetOffset_x (const unsigned int moff)
 Set offset in the state vector (position part) Note: only the ChSystem::Setup function should use this.
 
void SetOffset_w (const unsigned int moff)
 Set offset in the state vector (speed part) Note: only the ChSystem::Setup function should use this.
 
void SetOffset_L (const unsigned int moff)
 Set offset in the lagrangian multipliers Note: only the ChSystem::Setup function should use this.
 
virtual void IntStateGather (const unsigned int off_x, ChState &x, const unsigned int off_v, ChStateDelta &v, double &T)
 From item's state to global state vectors y={x,v} pasting the states at the specified offsets. More...
 
virtual void IntStateScatter (const unsigned int off_x, const ChState &x, const unsigned int off_v, const ChStateDelta &v, const double T)
 From global state vectors y={x,v} to item's state (and update) fetching the states at the specified offsets. More...
 
virtual void IntStateGatherAcceleration (const unsigned int off_a, ChStateDelta &a)
 From item's state acceleration to global acceleration vector. More...
 
virtual void IntStateScatterAcceleration (const unsigned int off_a, const ChStateDelta &a)
 From global acceleration vector to item's state acceleration. More...
 
virtual void IntStateGatherReactions (const unsigned int off_L, ChVectorDynamic<> &L)
 From item's reaction forces to global reaction vector. More...
 
virtual void IntStateScatterReactions (const unsigned int off_L, const ChVectorDynamic<> &L)
 From global reaction vector to item's reaction forces. More...
 
virtual void IntStateIncrement (const unsigned int off_x, ChState &x_new, const ChState &x, const unsigned int off_v, const ChStateDelta &Dv)
 Computes x_new = x + Dt , using vectors at specified offsets. More...
 
virtual void IntLoadResidual_Mv (const unsigned int off, ChVectorDynamic<> &R, const ChVectorDynamic<> &w, const double c)
 Takes the 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 for a solution: From a vector R into the F 'force' term of the variables From a vector Qc into the Qb 'constraint' term of the constraints From a vector v into the q 'unknowns' term of the variables (for warm starting) From a vector L into the L 'lagrangian ' term of the constraints (for warm starting) 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: To a vector v from the q 'unknowns' term of the variables To a vector L from the L 'lagrangian ' term of the constraints. 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. More...
 
virtual void InjectConstraints (ChSystemDescriptor &mdescriptor)
 Tell to a system descriptor that there are contraints of type ChConstraint in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this. More...
 
virtual void ConstraintsBiReset ()
 Sets to zero the known term (b_i) of encapsulated ChConstraints.
 
virtual void ConstraintsBiLoad_C (double factor=1, double recovery_clamp=0.1, bool do_clamp=false)
 Adds the current C (constraint violation) to the known term (b_i) of encapsulated ChConstraints.
 
virtual void ConstraintsBiLoad_Ct (double factor=1)
 Adds the current Ct (partial t-derivative, as in C_dt=0-> [Cq]*q_dt=-Ct) to the known term (b_i) of encapsulated ChConstraints.
 
virtual void ConstraintsBiLoad_Qc (double factor=1)
 Adds the current Qc (the vector of C_dtdt=0 -> [Cq]*q_dtdt=Qc ) to the known term (b_i) of encapsulated ChConstraints.
 
virtual void ConstraintsLoadJacobians ()
 Adds the current jacobians in encapsulated ChConstraints.
 
virtual void ConstraintsFetch_react (double factor=1)
 Fetches the reactions from the lagrangian multiplier (l_i) of encapsulated ChConstraints. More...
 
virtual void InjectKRMmatrices (ChSystemDescriptor &mdescriptor)
 Tell to a system descriptor that there are items of type ChKblock in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this. More...
 
virtual void KRMmatricesLoad (double Kfactor, double Rfactor, double Mfactor)
 Adds the current stiffness K and damping R and mass M matrices in encapsulated ChKblock item(s), if any. More...
 
- Public Member Functions inherited from chrono::ChObj
 ChObj (const ChObj &other)
 
int GetIdentifier () const
 Gets the numerical identifier of the object.
 
void SetIdentifier (int id)
 Sets the numerical identifier of the object.
 
double GetChTime () const
 Gets the simulation time of this object.
 
void SetChTime (double m_time)
 Sets the simulation time of this object.
 
const char * GetName () const
 Gets the name of the object as C Ascii null-terminated string -for reading only!
 
void SetName (const char myname[])
 Sets the name of this object, as ascii string.
 
std::string GetNameString () const
 Gets the name of the object as C Ascii null-terminated string.
 
void SetNameString (const std::string &myname)
 Sets the name of this object, as std::string.
 
void MFlagsSetAllOFF (int &mflag)
 
void MFlagsSetAllON (int &mflag)
 
void MFlagSetON (int &mflag, int mask)
 
void MFlagSetOFF (int &mflag, int mask)
 
int MFlagGet (int &mflag, int mask)
 

Protected Attributes

ChSpringForceCallbackm_force_fun
 functor for force calculation
 
double m_rest_length
 undeform length
 
double m_force
 resulting force in dist. coord
 
- Protected Attributes inherited from chrono::ChPhysicsItem
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
 

Member Function Documentation

void chrono::ChLinkSpringCB::ArchiveIN ( ChArchiveIn marchive)
overridevirtual

Method to allow deserialization of transient data from archives.

Method to allow de serialization of transient data from archives.

Reimplemented from chrono::ChLinkMarkers.

void chrono::ChLinkSpringCB::Initialize ( std::shared_ptr< ChBody body1,
std::shared_ptr< ChBody body2,
bool  pos_are_relative,
ChVector<>  pos1,
ChVector<>  pos2,
bool  auto_rest_length = true,
double  rest_length = 0 
)

Specialized initialization for springs, given the two bodies to be connected, the positions of the two anchor endpoints of the spring (each expressed in body or abs.

coordinates) and the imposed rest length of the spring. NOTE! As in ChLinkMarkers::Initialize(), the two markers are automatically created and placed inside the two connected bodies.

Parameters
body1first body to link
body2second body to link
pos_are_relativetrue: following pos. are relative to bodies
pos1pos. of spring endpoint for 1st body (rel. or abs., see flag above)
pos2pos. of spring endpoint for 2nd body (rel. or abs., see flag above)
auto_rest_lengthif true, initializes the rest length as the distance between pos1 and pos2
rest_lengthrest length (no need to define if auto_rest_length=true.)