chrono::ChConstraintTwoGeneric Class Reference
Description
This class implements the functionality for a constraint between a COUPLE of TWO objects of type ChVariables(), with generic number of scalar variables each (ex.ChVariablesGeneric() or ChVariablesBody() ) and defines two constraint matrices, whose column number automatically matches the number of elements in variables vectors.
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 <ChConstraintTwoGeneric.h>
Inheritance diagram for chrono::ChConstraintTwoGeneric:
Collaboration diagram for chrono::ChConstraintTwoGeneric:
Public Member Functions | |
| ChConstraintTwoGeneric () | |
| Default constructor. | |
| ChConstraintTwoGeneric (ChVariables *mvariables_a, ChVariables *mvariables_b) | |
| Construct and immediately set references to variables. | |
| ChConstraintTwoGeneric (const ChConstraintTwoGeneric &other) | |
| Copy constructor. | |
| virtual ChConstraintTwoGeneric * | Clone () const override |
| "Virtual" copy constructor (covariant return type). | |
| ChConstraintTwoGeneric & | operator= (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 objects, each of ChVariables type, automatically creating/resizing jacobians if needed. | |
| virtual void | Update_auxiliary () override |
| This function updates the following auxiliary data: More... | |
| virtual double | Compute_Cq_q () override |
| This function must computes the product between the row-jacobian of this constraint '[Cq_i]' and the vector of variables, 'v'. More... | |
| virtual void | Increment_q (const double deltal) override |
| This function must increment the vector of variables 'v' with the quantity [invM]*[Cq_i]'deltal,that is v+=[invM][Cq_i]'*deltal or better: v+=[Eq_i]*deltal This is used for some iterative solvers. | |
| virtual void | MultiplyAndAdd (double &result, const ChVectorDynamic< double > &vect) const override |
| Computes the product of the corresponding block in the system matrix by 'vect', and add to 'result'. More... | |
| virtual void | MultiplyTandAdd (ChVectorDynamic< double > &result, double l) override |
| Computes the product of the corresponding transposed blocks in the system matrix (ie. More... | |
| virtual void | Build_Cq (ChSparseMatrix &storage, int insrow) override |
| Puts the two jacobian parts into the 'insrow' row of a sparse matrix, where both portions of the jacobian are shifted in order to match the offset of the corresponding ChVariable. | |
| virtual void | Build_CqT (ChSparseMatrix &storage, int inscol) override |
| Same as Build_Cq, but puts the transposed jacobian row as a column. | |
| virtual void | ArchiveOUT (ChArchiveOut &marchive) override |
| Method to allow serialization of transient data to archives. | |
| virtual void | ArchiveIN (ChArchiveIn &marchive) override |
| Method to allow de-serialization of transient data from archives. | |
 Public Member Functions inherited from chrono::ChConstraintTwo | |
| ChConstraintTwo () | |
| Default constructor. | |
| ChConstraintTwo (const ChConstraintTwo &other) | |
| Copy constructor. | |
| ChConstraintTwo & | operator= (const ChConstraintTwo &other) |
| Assignment operator: copy from other object. | |
| ChVariables * | GetVariables_a () |
| Access the first variable object. | |
| ChVariables * | GetVariables_b () |
| Access the second variable object. | |
| Public Member Functions inherited from chrono::ChConstraint | |
| ChConstraint () | |
| Default constructor. | |
| ChConstraint (const ChConstraint &other) | |
| Copy constructor. | |
| ChConstraint & | operator= (const ChConstraint &other) |
| Assignment operator: copy from other object. | |
| bool | operator== (const ChConstraint &other) const |
| Comparison (compares only flags, not the jacobians etc.) | |
| virtual bool | IsValid () const |
| Tells if the constraint data is currently valid. | |
| virtual void | SetValid (bool mon) |
| Use this function to set the valid state (child class Children classes must use this function depending on the result of their implementations of RestoreReference();. | |
| virtual bool | IsDisabled () const |
| Tells if the constraint is currently turned on or off by the user. | |
| virtual void | SetDisabled (bool mon) |
| User can use this to enable/disable the constraint as desired. | |
| virtual bool | IsRedundant () const |
| Tells if the constraint is redundant or singular. | |
| virtual void | SetRedundant (bool mon) |
| Solvers may use the following to mark a constraint as redundant. | |
| virtual bool | IsBroken () const |
| Tells if the constraint is broken, for excess of pulling/pushing. | |
| virtual void | SetBroken (bool mon) |
| 3rd party software can set the 'broken' status via this method (by default, constraints never break); | |
| virtual bool | IsUnilateral () const |
| Tells if the constraint is unilateral (typical complementarity constraint). | |
| virtual bool | IsLinear () const |
| Tells if the constraint is linear (if non linear, returns false). | |
| eChConstraintMode | GetMode () const |
| Gets the mode of the constraint: free / lock / complementary A typical constraint has 'lock = true' by default. | |
| void | SetMode (eChConstraintMode mmode) |
| Sets the mode of the constraint: free / lock / complementary. | |
| virtual bool | IsActive () const |
| Tells if the constraint is currently active, in general, that is tells if it must be included into the system solver or not. More... | |
| virtual void | SetActive (bool isactive) |
| Set the status of the constraint to active. | |
| virtual double | Compute_c_i () |
| Compute the residual of the constraint using the LINEAR expression. More... | |
| double | Get_c_i () const |
| Return the residual 'c_i' of this constraint. // CURRENTLY NOT USED. | |
| void | Set_b_i (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 | Get_b_i () const |
| Return the known term b_i in [Cq_i]*q + b_i = 0, where: c_i= [Cq_i]*q + b_i = 0. | |
| void | Set_cfm_i (const double mcfm) |
| Sets the constraint force mixing term (default=0). More... | |
| double | Get_cfm_i () const |
| Returns the constraint force mixing term. | |
| virtual void | Set_l_i (double ml_i) |
| Sets the 'l_i' value (constraint reaction, see 'l' vector) | |
| virtual double | Get_l_i () const |
| Return the 'l_i' value (constraint reaction, see 'l' vector) | |
| double | Get_g_i () const |
| Return the 'g_i' product , that is [Cq_i]*[invM_i]*[Cq_i]' (+cfm) | |
| void | Set_g_i (double m_g_i) |
| Usually you should not use the Set_g_i function, because g_i should be automatically computed during the Update_auxiliary() . | |
| virtual void | Project () |
| 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) |
| 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. More... | |
| void | SetOffset (int moff) |
| Set offset in global q vector (set automatically by ChSystemDescriptor) | |
| int | GetOffset () const |
| Get offset in global q vector. | |
Protected Attributes | |
| 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 | |
| ChVariables * | variables_a |
| The first constrained object. | |
| ChVariables * | variables_b |
| The second constrained object. | |
| Protected Attributes inherited from chrono::ChConstraint | |
| double | c_i |
| The 'c_i' residual of the constraint (if satisfied, c must be 0) | |
| double | l_i |
| The 'l_i' lagrangian multiplier (reaction) | |
| double | b_i |
| The 'b_i' right term in [Cq_i]*q+b_i=0 , note: c_i= [Cq_i]*q + b_i. | |
| double | cfm_i |
| The constraint force mixing, if needed (usually is zero) to add some numerical 'compliance' in the constraint, that is the equation becomes: c_i= [Cq_i]*q + b_i + cfm*l_i =0; Example, it could be cfm = [k * h^2](^-1) where k is stiffness. | |
| eChConstraintMode | mode |
| mode of the constraint: free / lock / complementar | |
| double | g_i |
| 'g_i' product [Cq_i]*[invM_i]*[Cq_i]' (+cfm) | |
| int | offset |
| offset in global "l" state vector (needed by some solvers) | |
Member Function Documentation
◆ Compute_Cq_q()
|
overridevirtual |
This function must computes the product between the row-jacobian of this constraint '[Cq_i]' and the vector of variables, 'v'.
that is CV=[Cq_i]*v This is used for some iterative solvers.
Implements chrono::ChConstraint.
◆ MultiplyAndAdd()
|
overridevirtual |
Computes the product of the corresponding block in the system matrix by 'vect', and add to 'result'.
NOTE: the 'vect' vector must already have the size of the total variables&constraints in the system; the procedure will use the ChVariable offsets (that must be already updated) to know the indexes in result and vect;
Implements chrono::ChConstraint.
◆ MultiplyTandAdd()
|
overridevirtual |
Computes the product of the corresponding transposed blocks in the system matrix (ie.
the TRANSPOSED jacobian matrix C_q') by 'l', and add to 'result'. NOTE: the 'result' vector must already have the size of the total variables&constraints in the system; the procedure will use the ChVariable offsets (that must be already updated) to know the indexes in result and vect;
Implements chrono::ChConstraint.
◆ Update_auxiliary()
|
overridevirtual |
This function updates the following auxiliary data:
- the Eq_a and Eq_b matrices
- the g_i product This is often called by solvers at the beginning of the solution process. Most often, inherited classes won't need to override this.
Reimplemented from chrono::ChConstraint.
The documentation for this class was generated from the following files:
- /builds/uwsbel/chrono/src/chrono/solver/ChConstraintTwoGeneric.h
- /builds/uwsbel/chrono/src/chrono/solver/ChConstraintTwoGeneric.cpp
