chrono::ChConstraintTwoTuplesRollingN< Ta, Tb > Class Template Reference

Description

template<class Ta, class Tb>
class chrono::ChConstraintTwoTuplesRollingN< Ta, Tb >

Normal reaction between two objects, each represented by a tuple of ChVariables objects.

Used ONLY when also two ChConstraintTwoTuplesFrictionT objects are used to represent friction. If these two tangent constraint are not used, for frictionless case, use a simple ChConstraintTwo with the ChConstraint::Mode::UNILATERAL mode.

Differently from an unilateral constraint, this does not enforce projection on positive constraint, since it will be up to the 'companion' ChConstraintTwoTuplesFrictionT objects to call a projection on the cone, by modifying all the three components (normal, u, v) at once.

Templates Ta and Tb are of ChVariableTupleCarrier_Nvars classes.

#include <ChConstraintTwoTuplesRollingN.h>

Inheritance diagram for chrono::ChConstraintTwoTuplesRollingN< Ta, Tb >:
Collaboration diagram for chrono::ChConstraintTwoTuplesRollingN< Ta, Tb >:

Public Member Functions

 ChConstraintTwoTuplesRollingN (const ChConstraintTwoTuplesRollingN &other)
 
virtual ChConstraintTwoTuplesRollingNClone () const override
 "Virtual" copy constructor (covariant return type).
 
ChConstraintTwoTuplesRollingNoperator= (const ChConstraintTwoTuplesRollingN &other)
 Assignment operator: copy from other object.
 
float GetRollingFrictionCoefficient ()
 Get the rolling friction coefficient.
 
void SetRollingFrictionCoefficient (float mcoeff)
 Set the rolling friction coefficient.
 
float GetSpinningFrictionCoefficient ()
 Get the spinning friction coefficient.
 
void SetSpinningFrictionCoefficient (float mcoeff)
 Set the spinning friction coefficient.
 
ChConstraintTwoTuplesRollingT< Ta, Tb > * GetRollingConstraintU ()
 Get pointer to U tangential component.
 
ChConstraintTwoTuplesRollingT< Ta, Tb > * GetRollingConstraintV ()
 Get pointer to V tangential component.
 
ChConstraintTwoTuplesContactN< Ta, Tb > * GetNormalConstraint ()
 Get pointer to normal contact component.
 
void SetRollingConstraintU (ChConstraintTwoTuplesRollingT< Ta, Tb > *mconstr)
 Set pointer to U tangential component.
 
void SetRollingConstraintV (ChConstraintTwoTuplesRollingT< Ta, Tb > *mconstr)
 Set pointer to V tangential component.
 
void SetNormalConstraint (ChConstraintTwoTuplesContactN< Ta, Tb > *mconstr)
 Set pointer to normal contact component.
 
virtual void Project () override
 For iterative solvers: project the value of a possible 'l_i' value of constraint reaction onto admissible set. More...
 
- Public Member Functions inherited from chrono::ChConstraintTwoTuples< Ta, Tb >
 ChConstraintTwoTuples (const ChConstraintTwoTuples &other)
 
ChConstraintTwoTuplesoperator= (const ChConstraintTwoTuples &other)
 Assignment operator: copy from other object.
 
type_constraint_tuple_a & Get_tuple_a ()
 Access tuple a.
 
type_constraint_tuple_b & Get_tuple_b ()
 Access tuple b.
 
virtual void Update_auxiliary () override
 This function updates the following auxiliary data: More...
 
virtual double ComputeJacobianTimesState () override
 Compute the product between the Jacobian of this constraint, [Cq_i], and the vector of variables. More...
 
virtual void IncrementState (double deltal) override
 Increment the vector of variables with the quantity [invM]*[Cq_i]'*deltal. More...
 
virtual void AddJacobianTimesVectorInto (double &result, ChVectorConstRef vect) const override
 Add the product of the corresponding block in the system matrix by 'vect' and add to result. More...
 
virtual void AddJacobianTransposedTimesScalarInto (ChVectorRef result, double l) const override
 Add the product of the corresponding transposed block in the system matrix by 'l' and add to result. More...
 
virtual void PasteJacobianInto (ChSparseMatrix &mat, unsigned int start_row, unsigned int start_col) const override
 Write the constraint Jacobian into the specified global matrix at the offsets of the associated variables. More...
 
virtual void PasteJacobianTransposedInto (ChSparseMatrix &mat, unsigned int start_row, unsigned int start_col) const override
 Write the transposed constraint Jacobian into the specified global matrix at the offsets of the associated variables. More...
 
- Public Member Functions inherited from chrono::ChConstraint
 ChConstraint (const ChConstraint &other)
 
ChConstraintoperator= (const ChConstraint &other)
 Assignment operator: copy from other object.
 
bool operator== (const ChConstraint &other) const
 Comparison (compares only flags, not the Jacobians).
 
bool IsValid () const
 Indicate if the constraint data is currently valid.
 
void SetValid (bool mon)
 Set the "valid" state of this constraint.
 
bool IsDisabled () const
 Indicate if the constraint is currently turned on or off.
 
void SetDisabled (bool mon)
 
bool IsRedundant () const
 Indicate if the constraint is redundant or singular.
 
void SetRedundant (bool mon)
 Mark the constraint as redundant.
 
bool IsBroken () const
 Indicate if the constraint is broken, due to excess pulling/pushing.
 
void SetBroken (bool mon)
 Set the constraint as broken. More...
 
virtual bool IsUnilateral () const
 Indicate if the constraint is unilateral (typical complementarity constraint).
 
virtual bool IsLinear () const
 Indicate if the constraint is linear.
 
Mode GetMode () const
 Get the mode of the constraint. More...
 
void SetMode (Mode mmode)
 Set the mode of the constraint.
 
bool IsActive () const
 Indicate whether the constraint is currently active. More...
 
void SetActive (bool isactive)
 Set the status of the constraint to active.
 
virtual double ComputeResidual ()
 Compute the residual of the constraint using the linear expression. More...
 
double GetResidual () const
 Return the residual of this constraint.
 
void SetRightHandSide (const double mb)
 Sets the known term b_i in [Cq_i]*q + b_i = 0, where: c_i = [Cq_i]*q + b_i = 0.
 
double GetRightHandSide () const
 Return the known term b_i in [Cq_i]*q + b_i = 0, where: c_i= [Cq_i]*q + b_i = 0.
 
void SetComplianceTerm (const double mcfm)
 Set the constraint force mixing term (default=0). More...
 
double GetComplianceTerm () const
 Return the constraint force mixing term.
 
void SetLagrangeMultiplier (double ml_i)
 Set the value of the corresponding Lagrange multiplier (constraint reaction).
 
double GetLagrangeMultiplier () const
 Return the corresponding Lagrange multiplier (constraint reaction).
 
double GetSchurComplement () const
 Return the 'g_i' product, that is [Cq_i]*[invM_i]*[Cq_i]' (+cfm)
 
void SetSchurComplement (double m_g_i)
 Usually you should not use the SetSchurComplement function, because g_i should be automatically computed during the Update_auxiliary() .
 
virtual double Violation (double mc_i)
 Return the constraint violation. More...
 
void SetOffset (unsigned int off)
 Set offset in global q vector (set automatically by ChSystemDescriptor)
 
unsigned int GetOffset () const
 Get offset in global q vector.
 
virtual void ArchiveOut (ChArchiveOut &archive_out)
 Method to allow serialization of transient data to archives.
 
virtual void ArchiveIn (ChArchiveIn &archive_in)
 Method to allow de-serialization of transient data from archives.
 

Protected Attributes

float rollingfriction
 the rolling friction coefficient
 
float spinningfriction
 the spinning friction coefficient
 
ChConstraintTwoTuplesRollingT< Ta, Tb > * constraint_U
 the pointer to U tangential component
 
ChConstraintTwoTuplesRollingT< Ta, Tb > * constraint_V
 the pointer to V tangential component
 
ChConstraintTwoTuplesContactN< Ta, Tb > * constraint_N
 the pointer to N component
 
- Protected Attributes inherited from chrono::ChConstraintTwoTuples< Ta, Tb >
type_constraint_tuple_a tuple_a
 
type_constraint_tuple_b tuple_b
 
- Protected Attributes inherited from chrono::ChConstraint
double c_i
 constraint residual (if satisfied, c must be 0)
 
double l_i
 Lagrange multiplier (reaction)
 
double b_i
 right-hand side term in [Cq_i]*q+b_i=0 , note: c_i= [Cq_i]*q + b_i
 
double cfm_i
 Constraint force mixing if needed to add some numerical 'compliance' in the constraint. More...
 
Mode mode
 mode of the constraint
 
double g_i
 product [Cq_i]*[invM_i]*[Cq_i]' (+cfm)
 
unsigned int offset
 offset in global "l" state vector (needed by some solvers)
 

Additional Inherited Members

- Public Types inherited from chrono::ChConstraint
enum  Mode { Mode::FREE, Mode::LOCK, Mode::UNILATERAL, Mode::FRICTION }
 Constraint mode. More...
 

Member Function Documentation

◆ Project()

template<class Ta, class Tb>
virtual void chrono::ChConstraintTwoTuplesRollingN< Ta, Tb >::Project ( )
inlineoverridevirtual

For iterative solvers: project the value of a possible 'l_i' value of constraint reaction onto admissible set.

This projection will also modify the l_i values of the two tangential friction constraints (projection onto the friction cone, as by Anitescu-Tasora theory).

Reimplemented from chrono::ChConstraint.


The documentation for this class was generated from the following file:
  • /builds/uwsbel/chrono/src/chrono/solver/ChConstraintTwoTuplesRollingN.h