Description

Base class for joints implemented using the "lock formulation".

Derived classes provide models for revolute, prismatic, spherical, etc. Note that certain kinematic joints (e.g., Universal) cannot be modeled using the lock formulation. Joints of this type can optionally specify 'limits' over upper-lower motions of their respective degrees of freedom, using the ChLinkLimit objects.

#include <ChLinkLock.h>

Inheritance diagram for chrono::ChLinkLock:
Collaboration diagram for chrono::ChLinkLock:

Public Types

using ChConstraintVectorX = Eigen::Matrix< double, Eigen::Dynamic, 1, Eigen::ColMajor, 7, 1 >
 
using ChConstraintMatrixX6 = Eigen::Matrix< double, Eigen::Dynamic, BODY_DOF, Eigen::RowMajor, 7, BODY_DOF >
 
using ChConstraintMatrixX7 = Eigen::Matrix< double, Eigen::Dynamic, BODY_QDOF, Eigen::RowMajor, 7, BODY_QDOF >
 

Public Member Functions

 ChLinkLock ()
 Default constructor. Builds a ChLinkLockSpherical.
 
 ChLinkLock (const ChLinkLock &other)
 Copy constructor.
 
virtual ChLinkLockClone () const override
 "Virtual" copy constructor (covariant return type).
 
int RestoreRedundant () override
 If some constraint is redundant, return to normal state.
 
virtual void SetDisabled (bool mdis) override
 Enable/disable all constraints of the link.
 
virtual void SetBroken (bool mon) override
 For example, a 3rd party software can set the 'broken' status via this method.
 
ChLinkMaskGetMask ()
 Get the link mask (a container for the ChConstraint items).
 
virtual void SetUpMarkers (ChMarker *mark1, ChMarker *mark2) override
 Set the two markers associated with this link.
 
virtual int GetDOC () override
 Get the number of scalar constraints for this link.
 
virtual int GetDOC_c () override
 Get the number of bilateral constraints for this link.
 
virtual int GetDOC_d () override
 Get the number of unilateral constraints for this link.
 
const ChConstraintVectorX & GetC () const
 Link violation (residuals of the link constraint equations).
 
const ChConstraintVectorX & GetC_dt () const
 Time derivatives of link violation.
 
const ChConstraintVectorX & GetC_dtdt () const
 Second time derivatives of link violation.
 
const ChConstraintMatrixX7 & GetCq1 () const
 The jacobian (body n.1 part, i.e. columns= 7 , rows= ndoc)
 
const ChConstraintMatrixX7 & GetCq2 () const
 The jacobian (body n.2 part, i.e. columns= 7 , rows= ndoc)
 
const ChConstraintMatrixX6 & GetCqw1 () const
 The jacobian for Wl (col 6, rows= ndoc), as [Cqw1_rot]=[Cq_rot]*[Gl_1]'.
 
const ChConstraintMatrixX6 & GetCqw2 () const
 The jacobian for Wl (col 6, rows= ndoc) as [Cqw2_rot]=[Cq_rot]*[Gl_2]'.
 
const ChConstraintVectorX & GetQc () const
 The gamma vector used in dynamics, [Cq]x''=Qc.
 
const ChConstraintVectorX & GetCt () const
 The Ct vector used in kinematics, [Cq]x'=Ct.
 
const ChConstraintVectorX & GetReact () const
 Access the reaction vector, after dynamics computations.
 
virtual void UpdateState ()
 Given current time and body state, computes the constraint differentiation to get the the state matrices Cq1, Cq2, Qc, Ct , and also C, C_dt, C_dtd. More...
 
virtual void UpdateForces (double mytime) override
 Updates the local F, M forces adding penalties from ChLinkLimit objects, if any.
 
void UpdateCqw ()
 Updates Cqw1 and Cqw2 given updated Cq1 and Cq2, i.e. More...
 
virtual void Update (double mytime, bool update_assets=true) override
 Full update. 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.
 
ChLinkForceGetForce_D ()
 Accessors for internal forces on free degrees of freedom. More...
 
ChLinkForceGetForce_R ()
 Accessors for internal forces on free degrees of freedom. More...
 
ChLinkForceGetForce_X ()
 Accessors for internal forces on free degrees of freedom. More...
 
ChLinkForceGetForce_Y ()
 Accessors for internal forces on free degrees of freedom. More...
 
ChLinkForceGetForce_Z ()
 Accessors for internal forces on free degrees of freedom. More...
 
ChLinkForceGetForce_Rx ()
 Accessors for internal forces on free degrees of freedom. More...
 
ChLinkForceGetForce_Ry ()
 Accessors for internal forces on free degrees of freedom. More...
 
ChLinkForceGetForce_Rz ()
 Accessors for internal forces on free degrees of freedom. More...
 
ChLinkLimitGetLimit_X ()
 Accessors for limits on free degrees of freedom. More...
 
ChLinkLimitGetLimit_Y ()
 Accessors for limits on free degrees of freedom. More...
 
ChLinkLimitGetLimit_Z ()
 Accessors for limits on free degrees of freedom. More...
 
ChLinkLimitGetLimit_Rx ()
 Accessors for limits on free degrees of freedom. More...
 
ChLinkLimitGetLimit_Ry ()
 Accessors for limits on free degrees of freedom. More...
 
ChLinkLimitGetLimit_Rz ()
 Accessors for limits on free degrees of freedom. More...
 
ChLinkLimitGetLimit_Rp ()
 Accessors for limits on free degrees of freedom. More...
 
ChLinkLimitGetLimit_D ()
 Accessors for limits on free degrees of freedom. 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, synchronize 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...
 
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_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 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 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)
 
virtual std::string & ArchiveContainerName ()
 

Protected Types

enum  LinkType {
  LOCK, SPHERICAL, POINTPLANE, POINTLINE,
  CYLINDRICAL, PRISMATIC, PLANEPLANE, OLDHAM,
  REVOLUTE, FREE, ALIGN, PARALLEL,
  PERPEND, TRAJECTORY, CLEARANCE, REVOLUTEPRISMATIC
}
 Type of link-lock.
 

Protected Member Functions

void BuildLink ()
 Resize matrices and initializes all mask-dependent quantities. More...
 
void BuildLinkType (LinkType link_type)
 Set the mask and then resize matrices.
 
void BuildLink (bool x, bool y, bool z, bool e0, bool e1, bool e2, bool e3)
 
void ChangeLinkType (LinkType new_link_type)
 
virtual void IntStateScatterReactions (const unsigned int off_L, const ChVectorDynamic<> &L) override
 From global reaction vector to item's reaction forces.
 
virtual void IntStateGatherReactions (const unsigned int off_L, ChVectorDynamic<> &L) override
 From item's reaction forces to global reaction vector.
 
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.
 
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.
 
virtual void IntLoadConstraint_Ct (const unsigned int off, ChVectorDynamic<> &Qc, const double c) override
 Takes the term Ct, scale and adds to Qc at given offset: Qc += c*Ct.
 
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:
 
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:
 
virtual void InjectConstraints (ChSystemDescriptor &mdescriptor) 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. More...
 
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 ConstraintsBiLoad_Ct (double factor=1) override
 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) override
 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 () 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...
 

Protected Attributes

LinkType type
 type of link_lock joint
 
ChLinkMaskLF mask
 scalar constraints
 
int ndoc
 number of degrees of constraint
 
int ndoc_c
 number of degrees of constraint (bilateral constraintss)
 
int ndoc_d
 number of degrees of constraint (unilateral constraints, excluding joint limits)
 
std::unique_ptr< ChLinkForceforce_D
 the force acting on the straight line m1-m2 (distance)
 
std::unique_ptr< ChLinkForceforce_R
 the torque acting about rotation axis
 
std::unique_ptr< ChLinkForceforce_X
 the force acting along X dof
 
std::unique_ptr< ChLinkForceforce_Y
 the force acting along Y dof
 
std::unique_ptr< ChLinkForceforce_Z
 the force acting along Z dof
 
std::unique_ptr< ChLinkForceforce_Rx
 the torque acting about Rx dof
 
std::unique_ptr< ChLinkForceforce_Ry
 the torque acting about Ry dof
 
std::unique_ptr< ChLinkForceforce_Rz
 the torque acting about Rz dof
 
double d_restlength
 the rest length of the "d_spring" spring
 
std::unique_ptr< ChLinkLimitlimit_X
 the upper/lower limits for X dof
 
std::unique_ptr< ChLinkLimitlimit_Y
 the upper/lower limits for Y dof
 
std::unique_ptr< ChLinkLimitlimit_Z
 the upper/lower limits for Z dof
 
std::unique_ptr< ChLinkLimitlimit_Rx
 the upper/lower limits for Rx dof
 
std::unique_ptr< ChLinkLimitlimit_Ry
 the upper/lower limits for Ry dof
 
std::unique_ptr< ChLinkLimitlimit_Rz
 the upper/lower limits for Rz dof
 
std::unique_ptr< ChLinkLimitlimit_Rp
 the polar (conical) limit for "shoulder"rotation
 
std::unique_ptr< ChLinkLimitlimit_D
 the polar (conical) limit for "shoulder"rotation
 
ChConstraintVectorX C
 C(q,q_dt,t), the constraint violations.
 
ChConstraintVectorX C_dt
 Speed constraint violations.
 
ChConstraintVectorX C_dtdt
 Acceleration constraint violations.
 
ChConstraintMatrixX7 Cq1
 [Cq1], the jacobian of the constraint, for coords1, [ndoc,7]
 
ChConstraintMatrixX7 Cq2
 [Cq2], the jacobian of the constraint, for coords2. [ndoc,7]
 
ChConstraintMatrixX6 Cqw1
 [Cqw1], the jacobian [ndoc,6] for 3 Wl rot.coordinates instead of quaternions
 
ChConstraintMatrixX6 Cqw2
 [Cqw2], the jacobian [ndoc,6] for 3 Wl rot.coordinates instead of quaternions
 
ChConstraintVectorX Qc
 {Qc}, the known part, {Qc}=-{C_dtdt}-([Cq]{q_dt})q-2[Cq_dt]{q_dt}
 
ChConstraintVectorX Ct
 partial derivative of the link kin. equation wrt to time
 
ChConstraintVectorX react
 {l}, the lagrangians forces in the constraints
 
ChMatrixNM< double, 7, BODY_QDOFCq1_temp
 
ChMatrixNM< double, 7, BODY_QDOFCq2_temp
 
ChVectorN< double, 7 > Qc_temp
 
Coordsys Ct_temp
 
- 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
 

Friends

class ChConveyor
 

Member Function Documentation

void chrono::ChLinkLock::BuildLink ( )
protected

Resize matrices and initializes all mask-dependent quantities.

Sets number of DOF and number DOC based on current mask information.

void chrono::ChLinkLock::ConstraintsFetch_react ( double  factor = 1)
overrideprotectedvirtual

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.

ChLinkForce & chrono::ChLinkLock::GetForce_D ( )

Accessors for internal forces on free degrees of freedom.

These functions provide access to initialize and set parameters for link forces acting on different degrees of freedom of the joint. Note that they use "lazy initialization"; an internal link force object is created on the first invocation of the corresponding accessor function.

ChLinkForce & chrono::ChLinkLock::GetForce_R ( )

Accessors for internal forces on free degrees of freedom.

These functions provide access to initialize and set parameters for link forces acting on different degrees of freedom of the joint. Note that they use "lazy initialization"; an internal link force object is created on the first invocation of the corresponding accessor function.

ChLinkForce & chrono::ChLinkLock::GetForce_Rx ( )

Accessors for internal forces on free degrees of freedom.

These functions provide access to initialize and set parameters for link forces acting on different degrees of freedom of the joint. Note that they use "lazy initialization"; an internal link force object is created on the first invocation of the corresponding accessor function.

ChLinkForce & chrono::ChLinkLock::GetForce_Ry ( )

Accessors for internal forces on free degrees of freedom.

These functions provide access to initialize and set parameters for link forces acting on different degrees of freedom of the joint. Note that they use "lazy initialization"; an internal link force object is created on the first invocation of the corresponding accessor function.

ChLinkForce & chrono::ChLinkLock::GetForce_Rz ( )

Accessors for internal forces on free degrees of freedom.

These functions provide access to initialize and set parameters for link forces acting on different degrees of freedom of the joint. Note that they use "lazy initialization"; an internal link force object is created on the first invocation of the corresponding accessor function.

ChLinkForce & chrono::ChLinkLock::GetForce_X ( )

Accessors for internal forces on free degrees of freedom.

These functions provide access to initialize and set parameters for link forces acting on different degrees of freedom of the joint. Note that they use "lazy initialization"; an internal link force object is created on the first invocation of the corresponding accessor function.

ChLinkForce & chrono::ChLinkLock::GetForce_Y ( )

Accessors for internal forces on free degrees of freedom.

These functions provide access to initialize and set parameters for link forces acting on different degrees of freedom of the joint. Note that they use "lazy initialization"; an internal link force object is created on the first invocation of the corresponding accessor function.

ChLinkForce & chrono::ChLinkLock::GetForce_Z ( )

Accessors for internal forces on free degrees of freedom.

These functions provide access to initialize and set parameters for link forces acting on different degrees of freedom of the joint. Note that they use "lazy initialization"; an internal link force object is created on the first invocation of the corresponding accessor function.

ChLinkLimit & chrono::ChLinkLock::GetLimit_D ( )

Accessors for limits on free degrees of freedom.

These functions provide access to initialize and set parameters for link limits on different free degrees of freedom of the joint. Note that they use "lazy initialization"; an internal link limit object is created on the first invocation of the corresponding accessor function.

ChLinkLimit & chrono::ChLinkLock::GetLimit_Rp ( )

Accessors for limits on free degrees of freedom.

These functions provide access to initialize and set parameters for link limits on different free degrees of freedom of the joint. Note that they use "lazy initialization"; an internal link limit object is created on the first invocation of the corresponding accessor function.

ChLinkLimit & chrono::ChLinkLock::GetLimit_Rx ( )

Accessors for limits on free degrees of freedom.

These functions provide access to initialize and set parameters for link limits on different free degrees of freedom of the joint. Note that they use "lazy initialization"; an internal link limit object is created on the first invocation of the corresponding accessor function.

ChLinkLimit & chrono::ChLinkLock::GetLimit_Ry ( )

Accessors for limits on free degrees of freedom.

These functions provide access to initialize and set parameters for link limits on different free degrees of freedom of the joint. Note that they use "lazy initialization"; an internal link limit object is created on the first invocation of the corresponding accessor function.

ChLinkLimit & chrono::ChLinkLock::GetLimit_Rz ( )

Accessors for limits on free degrees of freedom.

These functions provide access to initialize and set parameters for link limits on different free degrees of freedom of the joint. Note that they use "lazy initialization"; an internal link limit object is created on the first invocation of the corresponding accessor function.

ChLinkLimit & chrono::ChLinkLock::GetLimit_X ( )

Accessors for limits on free degrees of freedom.

These functions provide access to initialize and set parameters for link limits on different free degrees of freedom of the joint. Note that they use "lazy initialization"; an internal link limit object is created on the first invocation of the corresponding accessor function.

ChLinkLimit & chrono::ChLinkLock::GetLimit_Y ( )

Accessors for limits on free degrees of freedom.

These functions provide access to initialize and set parameters for link limits on different free degrees of freedom of the joint. Note that they use "lazy initialization"; an internal link limit object is created on the first invocation of the corresponding accessor function.

ChLinkLimit & chrono::ChLinkLock::GetLimit_Z ( )

Accessors for limits on free degrees of freedom.

These functions provide access to initialize and set parameters for link limits on different free degrees of freedom of the joint. Note that they use "lazy initialization"; an internal link limit object is created on the first invocation of the corresponding accessor function.

void chrono::ChLinkLock::InjectConstraints ( ChSystemDescriptor mdescriptor)
overrideprotectedvirtual

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.

Reimplemented from chrono::ChPhysicsItem.

void chrono::ChLinkLock::Update ( double  mytime,
bool  update_assets = true 
)
overridevirtual

Full update.

Fills-in all the matrices of the link, and does all required calculations by calling specific Update functions in sequence:

    UpdateTime;
    UpdateRelMarkerCoords;
    UpdateState;
    UpdateCqw
    UpdateForces;

Reimplemented from chrono::ChLinkMarkers.

void chrono::ChLinkLock::UpdateCqw ( )

Updates Cqw1 and Cqw2 given updated Cq1 and Cq2, i.e.

computes the jacobians with 'Wl' rotational coordinates knowing the jacobians for body rotations in quaternion coordinates.

void chrono::ChLinkLock::UpdateState ( )
virtual

Given current time and body state, computes the constraint differentiation to get the the state matrices Cq1, Cq2, Qc, Ct , and also C, C_dt, C_dtd.

Reimplemented in chrono::ChLinkLockLock, and chrono::ChLinkScrew.