chrono::ChLinkRSDA Class Reference

Description

Class for rotational spring-damper-actuator (RSDA) with the torque specified through a functor object.

By default, models a linear RSDA. The torque is applied in the current direction of the relative axis of rotation (the Z axis of the joint reference frame). It is the user's responsibility to ensure that the kinematics of the mechanism ensure that the two RSDA frames maintain their Z axes parallel. The angle is measured positive from the X RSDA axis on the first body to the X RSDA axis on the second body.

#include <ChLinkRSDA.h>

Inheritance diagram for chrono::ChLinkRSDA:
Collaboration diagram for chrono::ChLinkRSDA:

Classes

class  TorqueFunctor
 Class to be used as a callback interface for calculating the general spring-damper torque. More...
 

Public Member Functions

 ChLinkRSDA (const ChLinkRSDA &other)
 
virtual ChLinkRSDAClone () const override
 "Virtual" copy constructor (covariant return type).
 
void SetSpringCoefficient (double k)
 Set spring coefficient (default: 0). More...
 
void SetDampingCoefficient (double r)
 Set damping coefficient (default: 0). More...
 
void SetActuatorTorque (double t)
 Set constant actuation torque (default: 0). More...
 
void SetRestAngle (double rest_angle)
 Set the RSDA rest angle (in radians). More...
 
void SetNumInitRevolutions (int n)
 Set the number of initial RSDA revolutions (default: 0). More...
 
void RegisterTorqueFunctor (std::shared_ptr< TorqueFunctor > functor)
 Specify the callback object for calculating the torque.
 
double GetRestAngle () const
 Get the spring rest (free) angle.
 
double GetAngle () const
 Get current angle.
 
double GetDeformation () const
 Get current deformation.
 
double GetVelocity () const
 Get current angle rate of change.
 
double GetTorque () const
 Get current torque (in the direction of the torque element).
 
virtual ChCoordsys GetLinkRelativeCoords () override
 Get the link coordinate system, expressed relative to Body2. More...
 
virtual ChFrame GetVisualModelFrame (unsigned int nclone=0) override
 Get the reference frame (expressed in and relative to the absolute frame) of the visual model. More...
 
void Initialize (std::shared_ptr< ChBody > body1, std::shared_ptr< ChBody > body2, const ChCoordsys<> &csys)
 Initialize the rotational spring by specifying the two bodies to be connected and an RSDA frame specified in the absolute frame. More...
 
void Initialize (std::shared_ptr< ChBody > body1, std::shared_ptr< ChBody > body2, bool local, const ChCoordsys<> &csys1, const ChCoordsys<> &csys2)
 Initialize the rotational spring by specifying the two bodies to be connected and RSDA frames on each body. 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::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(). More...
 
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 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 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 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 IntStateGetIncrement (const unsigned int off_x, const ChState &x_new, const ChState &x, const unsigned int off_v, ChStateDelta &Dv)
 Computes Dt = x_new - x, 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 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 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...
 
- 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 ()
 

Friends

class ChRotSpringShape
 

Additional Inherited Members

- 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
 

Member Function Documentation

◆ ArchiveIN()

void chrono::ChLinkRSDA::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::ChLink.

◆ GetLinkRelativeCoords()

ChCoordsys chrono::ChLinkRSDA::GetLinkRelativeCoords ( )
overridevirtual

Get the link coordinate system, expressed relative to Body2.

This represents the 'main' reference of the link: reaction torques are expressed in this coordinate system.

Reimplemented from chrono::ChLink.

◆ GetVisualModelFrame()

ChFrame chrono::ChLinkRSDA::GetVisualModelFrame ( unsigned int  nclone = 0)
overridevirtual

Get the reference frame (expressed in and relative to the absolute frame) of the visual model.

Return the coordinate system on body1.

Reimplemented from chrono::ChLinkBase.

◆ Initialize() [1/2]

void chrono::ChLinkRSDA::Initialize ( std::shared_ptr< ChBody body1,
std::shared_ptr< ChBody body2,
bool  local,
const ChCoordsys<> &  csys1,
const ChCoordsys<> &  csys2 
)

Initialize the rotational spring by specifying the two bodies to be connected and RSDA frames on each body.

If local = true, it is assumed that these quantities are specified in the local body frames. Otherwise, it is assumed that they are specified in the absolute frame. The RSDA is constructed such that it acts on the (assumed common) Z axis of the joint frames. Unless SetRestAngle() is explicitly called, the RSDA rest angle is calculated from the initial configuration.

Parameters
body1first body frame
body2second body frame
localtrue if data given in body local frames
csys1RSDA frame orientation on body 1
csys2RSDA frame orientation on body 2

◆ Initialize() [2/2]

void chrono::ChLinkRSDA::Initialize ( std::shared_ptr< ChBody body1,
std::shared_ptr< ChBody body2,
const ChCoordsys<> &  csys 
)

Initialize the rotational spring by specifying the two bodies to be connected and an RSDA frame specified in the absolute frame.

The RSDA is constructed such that it acts on the Z axis of the joint frame. Unless SetRestAngle() is explicitly called, the RSDA rest angle is set to 0.

Parameters
body1first body frame
body2second body frame
csysRSDA frame orientation (in absolute frame)

◆ SetActuatorTorque()

void chrono::ChLinkRSDA::SetActuatorTorque ( double  t)
inline

Set constant actuation torque (default: 0).

Used only if no torque functor is provided (see RegisterTorqueFunctor).

◆ SetDampingCoefficient()

void chrono::ChLinkRSDA::SetDampingCoefficient ( double  r)
inline

Set damping coefficient (default: 0).

Used only if no torque functor is provided (see RegisterTorqueFunctor).

◆ SetNumInitRevolutions()

void chrono::ChLinkRSDA::SetNumInitRevolutions ( int  n)

Set the number of initial RSDA revolutions (default: 0).

This number can be either positive or negative.

◆ SetRestAngle()

void chrono::ChLinkRSDA::SetRestAngle ( double  rest_angle)

Set the RSDA rest angle (in radians).

By default, this is calculated from the initial configuration.

◆ SetSpringCoefficient()

void chrono::ChLinkRSDA::SetSpringCoefficient ( double  k)
inline

Set spring coefficient (default: 0).

Used only if no torque functor is provided (see RegisterTorqueFunctor).


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