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...
 
double GetSpringCoefficient () const
 Get the value of the spring coefficient. More...
 
double GetDampingCoefficient () const
 Get the value of the damping coefficient. More...
 
double GetActuatorTorque () const
 Get the constant acutation torque. More...
 
void RegisterTorqueFunctor (std::shared_ptr< TorqueFunctor > functor)
 Specify the callback object for calculating the torque.
 
std::shared_ptr< TorqueFunctorGetTorqueFunctor () const
 Return the functor object for calculating the torque (may be empty).
 
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 ChFrame GetFrame1Rel () const override
 Get the link frame 1, relative to body 1.
 
virtual ChFrame GetFrame2Rel () const override
 Get the link frame 2, relative to body 2.
 
virtual ChFrame GetVisualModelFrame (unsigned int nclone=0) const 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 ChFrame<> &frame)
 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 ChFrame<> &frame1, const ChFrame<> &frame2)
 Initialize the rotational spring by specifying the two bodies to be connected and RSDA frames on each body. More...
 
virtual void ArchiveOut (ChArchiveOut &archive_out) override
 Method to allow serialization of transient data to archives.
 
virtual void ArchiveIn (ChArchiveIn &archive_in) override
 Method to allow deserialization of transient data from archives. 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 IsCollisionEnabled () const
 Tell if the object is subject to collision. More...
 
virtual void AddCollisionModelsToSystem (ChCollisionSystem *coll_sys) const
 Add to the provided collision system any collision models managed by this physics item. More...
 
virtual void RemoveCollisionModelsFromSystem (ChCollisionSystem *coll_sys) const
 Remove from the provided collision system any collision models managed by this physics item. More...
 
virtual void SyncCollisionModels ()
 Synchronize the position and bounding box of any collsion models managed by this physics item.
 
virtual ChAABB GetTotalAABB () const
 Get the axis-aligned bounding box (AABB) of this object. More...
 
virtual ChVector3d GetCenter () const
 Get a symbolic 'center' of the object. More...
 
virtual void Setup ()
 Perform setup operations. More...
 
void UpdateVisualModel ()
 Utility function to update only the associated visual assets (if any).
 
virtual void ForceToRest ()
 Set zero speed (and zero accelerations) in state, without changing the position. More...
 
virtual unsigned int GetNumCoordsPosLevel ()
 Get the number of coordinates at the position level. More...
 
virtual unsigned int GetNumCoordsVelLevel ()
 Get the number of coordinates at the velocity level. More...
 
virtual unsigned int GetNumConstraints ()
 Get the number of scalar constraints.
 
virtual unsigned int GetNumConstraintsBilateral ()
 Get the number of bilateral scalar constraints.
 
virtual unsigned int GetNumConstraintsUnilateral ()
 Get the number of unilateral scalar constraints.
 
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 IntLoadLumpedMass_Md (const unsigned int off, ChVectorDynamic<> &Md, double &err, const double c)
 Adds the lumped mass to a Md vector, representing a mass diagonal matrix. More...
 
virtual void IntLoadResidual_CqL (const unsigned int off_L, ChVectorDynamic<> &R, const ChVectorDynamic<> &L, const double c)
 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 InjectVariables (ChSystemDescriptor &descriptor)
 Register with the given system descriptor any ChVariable objects associated with this item.
 
virtual void InjectConstraints (ChSystemDescriptor &descriptor)
 Register with the given system descriptor any ChConstraint objects associated with this item.
 
virtual void LoadConstraintJacobians ()
 Compute and load current Jacobians in encapsulated ChConstraint objects.
 
virtual void InjectKRMMatrices (ChSystemDescriptor &descriptor)
 Register with the given system descriptor any ChKRMBlock objects associated with this item.
 
virtual void LoadKRMMatrices (double Kfactor, double Rfactor, double Mfactor)
 Compute and load current stiffnes (K), damping (R), and mass (M) matrices in encapsulated ChKRMBlock objects. 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 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 ConstraintsFetch_react (double factor=1)
 Fetches the reactions from the lagrangian multiplier (l_i) of encapsulated ChConstraints. More...
 
- Public Member Functions inherited from chrono::ChObj
 ChObj (const ChObj &other)
 
int GetIdentifier () const
 Get the unique integer identifier of this object. More...
 
void SetTag (int tag)
 Set an object integer tag (default: -1). More...
 
int GetTag () const
 Get the tag of this object.
 
void SetName (const std::string &myname)
 Set the name of this object.
 
const std::string & GetName () const
 Get the name of this object.
 
double GetChTime () const
 Gets the simulation time of this object.
 
void SetChTime (double m_time)
 Sets the simulation time of this object.
 
virtual std::string & ArchiveContainerName ()
 

Friends

class ChVisualShapeRotSpring
 

Additional Inherited Members

- Protected Member Functions inherited from chrono::ChObj
int GenerateUniqueIdentifier ()
 
- Protected Attributes inherited from chrono::ChPhysicsItem
ChSystemsystem
 parent system
 
std::shared_ptr< ChVisualModelInstancevis_model_instance
 instantiated visualization model
 
std::vector< std::shared_ptr< ChCamera > > cameras
 set of cameras
 
unsigned int offset_x
 offset in vector of state (position part)
 
unsigned int offset_w
 offset in vector of state (speed part)
 
unsigned int offset_L
 offset in vector of lagrangian multipliers
 
- Protected Attributes inherited from chrono::ChObj
double ChTime
 object simulation time
 
std::string m_name
 object name
 
int m_identifier
 object unique identifier
 
int m_tag
 user-supplied tag
 

Member Function Documentation

◆ ArchiveIn()

void chrono::ChLinkRSDA::ArchiveIn ( ChArchiveIn archive_in)
overridevirtual

Method to allow deserialization of transient data from archives.

Method to allow de serialization of transient data from archives.

Reimplemented from chrono::ChLink.

◆ GetActuatorTorque()

double chrono::ChLinkRSDA::GetActuatorTorque ( ) const
inline

Get the constant acutation torque.

Meaningful only if no torque functor is provided.

◆ GetDampingCoefficient()

double chrono::ChLinkRSDA::GetDampingCoefficient ( ) const
inline

Get the value of the damping coefficient.

Meaningful only if no torque functor is provided.

◆ GetSpringCoefficient()

double chrono::ChLinkRSDA::GetSpringCoefficient ( ) const
inline

Get the value of the spring coefficient.

Meaningful only if no torque functor is provided.

◆ GetVisualModelFrame()

ChFrame chrono::ChLinkRSDA::GetVisualModelFrame ( unsigned int  nclone = 0) const
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 ChFrame<> &  frame1,
const ChFrame<> &  frame2 
)

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
frame1RSDA frame orientation on body 1
frame2RSDA frame orientation on body 2

◆ Initialize() [2/2]

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

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
frameRSDA frame orientation (in absolute reference 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