chrono::ChConstraintTwoGenericBoxed Class Reference

Description

This class is inherited from the base ChConstraintTwoGeneric, which can be used for most pairwise constraints, and adds the feature that the multiplier must be l_min < l < l_max that is, the multiplier is 'boxed'.

Note that, if l_min = 0 and l_max = infinite, this can work also as an unilateral constraint.. Before starting the solver one must provide the proper values in constraints (and update them if necessary), i.e. must set at least the c_i and b_i values, and jacobians.

#include <ChConstraintTwoGenericBoxed.h>

Inheritance diagram for chrono::ChConstraintTwoGenericBoxed:
Collaboration diagram for chrono::ChConstraintTwoGenericBoxed:

Public Member Functions

 ChConstraintTwoGenericBoxed ()
 Default constructor.
 
 ChConstraintTwoGenericBoxed (ChVariables *mvariables_a, ChVariables *mvariables_b)
 Construct and immediately set references to variables.
 
 ChConstraintTwoGenericBoxed (const ChConstraintTwoGenericBoxed &other)
 Copy constructor.
 
virtual ChConstraintTwoGenericBoxedClone () const override
 "Virtual" copy constructor (covariant return type).
 
ChConstraintTwoGenericBoxedoperator= (const ChConstraintTwoGenericBoxed &other)
 Assignment operator: copy from other object.
 
void SetBoxedMinMax (double mmin, double mmax)
 Set lower/upper limit for the multiplier.
 
double GetBoxedMin ()
 Get the lower limit for the multiplier.
 
double GetBoxedMax ()
 Get the upper limit for the multiplier.
 
virtual void Project () override
 For iterative solvers: project the value of a possible 'l_i' value of constraint reaction onto admissible orthant/set. More...
 
virtual double Violation (double mc_i) override
 Given the residual of the constraint computed as the linear map mc_i = [Cq]*q + b_i + cfm*l_i , returns the violation of the constraint, considering inequalities, etc.
 
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 de-serialization of transient data from archives.
 
- Public Member Functions inherited from chrono::ChConstraintTwoGeneric
 ChConstraintTwoGeneric ()
 Default constructor.
 
 ChConstraintTwoGeneric (ChVariables *mvariables_a, ChVariables *mvariables_b)
 Construct and immediately set references to variables.
 
 ChConstraintTwoGeneric (const ChConstraintTwoGeneric &other)
 Copy constructor.
 
ChConstraintTwoGenericoperator= (const ChConstraintTwoGeneric &other)
 Assignment operator: copy from other object.
 
virtual ChRowVectorRef Get_Cq_a () override
 Access Jacobian vector.
 
virtual ChRowVectorRef Get_Cq_b () override
 Access Jacobian vector.
 
virtual ChVectorRef Get_Eq_a () override
 Access auxiliary vector (ex: used by iterative solvers).
 
virtual ChVectorRef Get_Eq_b () override
 Access auxiliary vector (ex: used by iterative solvers).
 
virtual void SetVariables (ChVariables *mvariables_a, ChVariables *mvariables_b) override
 Set references to the constrained ChVariables objects, automatically creating/resizing Jacobians as needed.
 
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::ChConstraintTwo
 ChConstraintTwo ()
 Default constructor.
 
 ChConstraintTwo (const ChConstraintTwo &other)
 Copy constructor.
 
ChConstraintTwooperator= (const ChConstraintTwo &other)
 Assignment operator: copy from other object.
 
ChVariablesGetVariables_a ()
 Access the first variable object.
 
ChVariablesGetVariables_b ()
 Access the second variable object.
 
- 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() .
 
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.
 

Protected Attributes

double l_min
 
double l_max
 
- Protected Attributes inherited from chrono::ChConstraintTwoGeneric
ChRowVectorDynamic< double > Cq_a
 The [Cq_a] jacobian of the constraint.
 
ChRowVectorDynamic< double > Cq_b
 The [Cq_b] jacobian of the constraint.
 
ChVectorDynamic< double > Eq_a
 The [Eq_a] product [Eq_a]=[invM_a]*[Cq_a]'.
 
ChVectorDynamic< double > Eq_b
 The [Eq_a] product [Eq_b]=[invM_b]*[Cq_b]'.
 
- Protected Attributes inherited from chrono::ChConstraintTwo
ChVariablesvariables_a
 The first constrained object.
 
ChVariablesvariables_b
 The second constrained object.
 
- 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()

void chrono::ChConstraintTwoGenericBoxed::Project ( )
overridevirtual

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

This 'boxed implementation overrides the default do-nothing case.

Reimplemented from chrono::ChConstraint.


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