Description
Class for modeling a composite revolute-spherical joint between two two ChBodyFrame objects.
This joint is defined through a point and direction on the first body (the revolute side), a point on the second body (the spherical side), and a distance. Kinematically, the two points are maintained at the prescribed distance while the vector between the two points is always perpendicular to the provided direction of the revolute joint.
#include <ChLinkRevoluteSpherical.h>
Public Member Functions | |
ChLinkRevoluteSpherical (const ChLinkRevoluteSpherical &other) | |
virtual ChLinkRevoluteSpherical * | Clone () const override |
"Virtual" copy constructor (covariant return type). | |
virtual int | GetDOC_c () override |
Get the number of (bilateral) constraints introduced by this joint. | |
const ChVector & | GetPoint1Rel () const |
Get the point on Body1 (revolute side), expressed in Body1 coordinate system. | |
const ChVector & | GetDir1Rel () const |
Get the direction of the revolute joint, expressed in Body1 coordinate system. | |
const ChVector & | GetPoint2Rel () const |
Get the point on Body2 (spherical side), expressed in Body2 coordinate system. | |
double | GetImposedDistance () const |
Get the imposed distance (length of massless connector). | |
double | GetCurrentDistance () const |
Get the current distance between the two points. | |
ChVector | GetPoint1Abs () const |
Get the point on Body1 (revolute side), expressed in absolute coordinate system. | |
ChVector | GetDir1Abs () const |
Get the direction of the revolute joint, expressed in absolute coordinate system. | |
ChVector | GetPoint2Abs () const |
Get the point on Body2 (spherical side), expressed in absolute coordinate system. | |
virtual ChCoordsys | GetLinkRelativeCoords () override |
Get the link coordinate system, expressed relative to Body2 (spherical side). More... | |
const ChVectorN< double, 2 > & | GetC () const |
Get the joint violation (residuals of the constraint equations) | |
void | Initialize (std::shared_ptr< ChBodyFrame > body1, std::shared_ptr< ChBodyFrame > body2, const ChCoordsys<> &csys, double distance) |
Initialize this joint by specifying the two bodies to be connected, a coordinate system specified in the absolute frame, and the distance of the massless connector. More... | |
void | Initialize (std::shared_ptr< ChBodyFrame > body1, std::shared_ptr< ChBodyFrame > body2, bool local, const ChVector<> &pos1, const ChVector<> &dir1, const ChVector<> &pos2, bool auto_distance=true, double distance=0) |
Initialize this joint by specifying the two bodies to be connected, a point and a direction on body1 defining the revolute joint, and a point on the second body defining the spherical joint. More... | |
virtual void | Update (double time, bool update_assets=true) override |
Perform the update of this joint at the specified time: compute jacobians, constraint violations, etc. 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 | 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 | 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 | InjectConstraints (ChSystemDescriptor &descriptor) 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 | 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 | ConstraintsLoadJacobians () override |
Adds the current jacobians in encapsulated ChConstraints. | |
virtual void | ConstraintsFetch_react (double factor=1) override |
Fetches the reactions from the lagrangian multiplier (l_i) of encapsulated ChConstraints. More... | |
ChVector | Get_react_force_body1 () |
ChVector | Get_react_torque_body1 () |
ChVector | Get_react_force_body2 () |
ChVector | Get_react_torque_body2 () |
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::ChLink | |
ChLink (const ChLink &other) | |
int | GetLeftDOF () |
Get the number of free degrees of freedom left by this link, between two bodies. | |
virtual int | GetNumCoords () override |
Get the number of scalar variables affected by constraints in this link. | |
ChBodyFrame * | GetBody1 () |
Get the constrained body '1', the 'slave' body. | |
ChBodyFrame * | GetBody2 () |
Get the constrained body '2', the 'master' body. | |
virtual ChCoordsys | GetLinkAbsoluteCoords () override |
Get the link coordinate system in absolute reference. More... | |
virtual ChVector | Get_react_force () override |
Get reaction force, expressed in link coordinate system. | |
virtual ChVector | Get_react_torque () override |
Get reaction torque, expressed in link coordinate system. | |
virtual int | RestoreRedundant () |
If some constraint is redundant, return to normal state //***OBSOLETE***. | |
virtual void | UpdateTime (double mytime) |
Given new time, current body state, update time-dependent quantities in link state, for example motion laws, moving markers, etc. More... | |
virtual void | Update (bool update_assets=true) override |
As above, but with current time. | |
virtual void | UpdatedExternalTime (double prevtime, double time) |
Called from a external package (i.e. a plugin, a CAD app.) to report that time has changed. | |
Public Member Functions inherited from chrono::ChLinkBase | |
ChLinkBase (const ChLinkBase &other) | |
bool | IsValid () |
Tells if the link data is currently valid. More... | |
void | SetValid (bool mon) |
Set the status of link validity. | |
bool | IsDisabled () |
Tells if all constraints of this link are currently turned on or off by the user. | |
virtual void | SetDisabled (bool mdis) |
User can use this to enable/disable all the constraint of the link as desired. | |
bool | IsBroken () |
Tells if the link is broken, for excess of pulling/pushing. | |
virtual void | SetBroken (bool mon) |
Set the 'broken' status vof this link. | |
bool | IsActive () |
An important function! Tells if the link is currently active, in general, that is tells if it must be included into the system solver or not. More... | |
virtual ChFrame | GetAssetsFrame (unsigned int nclone=0) override |
Get the master coordinate system for the assets, in absolute reference. More... | |
virtual bool | IsRequiringWaking () |
Tells if this link requires that the connected ChBody objects must be waken if they are sleeping. More... | |
Public Member Functions inherited from chrono::ChPhysicsItem | |
ChPhysicsItem (const ChPhysicsItem &other) | |
ChSystem * | GetSystem () 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< ChAsset > | GetAssetN (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, 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_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) |
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 | 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 | 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 | 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 | 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 | 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 () |
Additional Inherited Members | |
Protected Attributes inherited from chrono::ChLink | |
ChBodyFrame * | Body1 |
first connected body | |
ChBodyFrame * | Body2 |
second connected body | |
ChVector | react_force |
store the xyz reactions, expressed in local coordinate system of link; | |
ChVector | react_torque |
store the torque reactions, expressed in local coordinate system of link; | |
Protected Attributes inherited from chrono::ChLinkBase | |
bool | disabled |
all constraints of link disabled because of user needs | |
bool | valid |
link data is valid | |
bool | broken |
link is broken because of excessive pulling/pushing. | |
Protected Attributes inherited from chrono::ChPhysicsItem | |
ChSystem * | system |
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
◆ ArchiveIN()
|
overridevirtual |
Method to allow deserialization of transient data from archives.
Method to allow de serialization of transient data from archives.
Reimplemented from chrono::ChLink.
◆ ConstraintsFetch_react()
|
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.
◆ GetLinkRelativeCoords()
|
overridevirtual |
Get the link coordinate system, expressed relative to Body2 (spherical side).
This represents the 'main' reference of the link: reaction forces and reaction torques are reported in this coordinate system.
Reimplemented from chrono::ChLink.
◆ Initialize() [1/2]
void chrono::ChLinkRevoluteSpherical::Initialize | ( | std::shared_ptr< ChBodyFrame > | body1, |
std::shared_ptr< ChBodyFrame > | body2, | ||
bool | local, | ||
const ChVector<> & | pos1, | ||
const ChVector<> & | dir1, | ||
const ChVector<> & | pos2, | ||
bool | auto_distance = true , |
||
double | distance = 0 |
||
) |
Initialize this joint by specifying the two bodies to be connected, a point and a direction on body1 defining the revolute joint, and a point on the second body defining the spherical joint.
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 imposed distance between the two points can be either inferred from the provided configuration (auto_distance = true) or specified explicitly.
- Parameters
-
body1 first frame (revolute side) body2 second frame (spherical side) local true if data given in body local frames pos1 point on first frame (center of revolute) dir1 direction of revolute on first frame pos2 point on second frame (center of spherical) auto_distance true if imposed distance equal to |pos1 - po2| distance imposed distance (used only if auto_distance = false)
◆ Initialize() [2/2]
void chrono::ChLinkRevoluteSpherical::Initialize | ( | std::shared_ptr< ChBodyFrame > | body1, |
std::shared_ptr< ChBodyFrame > | body2, | ||
const ChCoordsys<> & | csys, | ||
double | distance | ||
) |
Initialize this joint by specifying the two bodies to be connected, a coordinate system specified in the absolute frame, and the distance of the massless connector.
The composite joint is constructed such that the direction of the revolute joint is aligned with the z axis of the specified coordinate system and the spherical joint is at the specified distance along the x axis.
- Parameters
-
body1 first frame (revolute side) body2 second frame (spherical side) csys joint coordinate system (in absolute frame) distance imposed distance
◆ IntFromDescriptor()
|
overridevirtual |
After a solver solution, fetch values from variables and constraints into vectors:
- Parameters
-
off_v offset for v v vector to where the q 'unknowns' term of the variables will be copied off_L offset for L L vector to where L 'lagrangian ' term of the constraints will be copied
Reimplemented from chrono::ChPhysicsItem.
◆ IntLoadConstraint_C()
|
overridevirtual |
Takes the term C, scale and adds to Qc at given offset: Qc += c*C.
- Parameters
-
off offset in Qc residual Qc result: the Qc residual, Qc += c*C c a scaling factor do_clamp apply clamping to c*C? recovery_clamp value for min/max clamping of c*C
Reimplemented from chrono::ChPhysicsItem.
◆ IntLoadResidual_CqL()
|
overridevirtual |
Takes the term Cq'*L, scale and adds to R at given offset: R += c*Cq'*L.
- Parameters
-
off_L offset in L multipliers R result: the R residual, R += c*Cq'*L L the L vector c a scaling factor
Reimplemented from chrono::ChPhysicsItem.
◆ IntStateGatherReactions()
|
overridevirtual |
From item's reaction forces to global reaction vector.
- Parameters
-
off_L offset in L vector L L vector of reaction forces
Reimplemented from chrono::ChPhysicsItem.
◆ IntStateScatterReactions()
|
overridevirtual |
From global reaction vector to item's reaction forces.
- Parameters
-
off_L offset in L vector L L vector of reaction forces
Reimplemented from chrono::ChPhysicsItem.
◆ IntToDescriptor()
|
overridevirtual |
Prepare variables and constraints to accommodate a solution:
- Parameters
-
off_v offset for v and R v vector that will be copied into the q 'unknowns' term of the variables (for warm starting) R vector that will be copied into the F 'force' term of the variables off_L offset for L and Qc L vector that will be copied into the L 'lagrangian ' term of the constraints (for warm starting) Qc vector that will be copied into the Qb 'constraint' term of the constraints
Reimplemented from chrono::ChPhysicsItem.
◆ Update()
|
overridevirtual |
Perform the update of this joint at the specified time: compute jacobians, constraint violations, etc.
and cache in internal structures
Reimplemented from chrono::ChLink.
The documentation for this class was generated from the following files:
- /builds/uwsbel/chrono/src/chrono/physics/ChLinkRevoluteSpherical.h
- /builds/uwsbel/chrono/src/chrono/physics/ChLinkRevoluteSpherical.cpp