SimTK::Constraint::ConstantSpeed Class Reference
Constrain a single mobility to have a particular speed. More...
Inheritance diagram for SimTK::Constraint::ConstantSpeed:
Public Member Functions | |
| ConstantSpeed (MobilizedBody &mobilizer, MobilizerUIndex whichU, Real defaultSpeed) | |
| Construct a constant speed constraint on a particular mobility of the given mobilizer. More... | |
| ConstantSpeed (MobilizedBody &mobilizer, Real defaultSpeed) | |
| Construct a constant speed constraint on the mobility of the given mobilizer, assuming there is only one mobility. More... | |
| ConstantSpeed () | |
| Default constructor creates an empty handle you can use to reference any existing ConstantSpeed Constraint. More... | |
| MobilizedBodyIndex | getMobilizedBodyIndex () const |
| Return the index of the mobilized body to which this constant speed constraint is being applied (to one of its mobilities). More... | |
| MobilizerUIndex | getWhichU () const |
| Return the particular mobility whose generalized speed is controlled by this ConstantSpeed constraint. More... | |
| Real | getDefaultSpeed () const |
| Return the default value for the speed to be enforced. More... | |
| ConstantSpeed & | setDefaultSpeed (Real speed) |
| Change the default value for the speed to be enforced by this constraint. More... | |
| void | setSpeed (State &state, Real speed) const |
| Override the default speed with this one whose value is stored in the given State. More... | |
| Real | getSpeed (const State &state) const |
| Get the current value of the speed set point from the indicated State. More... | |
| Real | getVelocityError (const State &state) const |
| Return the amount by which the given State fails to satisfy this ConstantSpeed constraint. More... | |
| Real | getAccelerationError (const State &state) const |
| Return the amount by which the accelerations in the given State fail to satify the time derivative of this constraint (which must be zero). More... | |
| Real | getMultiplier (const State &state) const |
| Get the value of the Lagrange multiplier generated to satisfy this constraint. More... | |
| Public Member Functions inherited from SimTK::Constraint | |
| Constraint () | |
| Default constructor creates an empty Constraint handle that can be used to reference any Constraint. More... | |
| Constraint (ConstraintImpl *r) | |
| For internal use: construct a new Constraint handle referencing a particular implementation object. More... | |
| void | disable (State &) const |
| Disable this Constraint, effectively removing it from the system. More... | |
| void | enable (State &) const |
| Enable this Constraint, without necessarily satisfying it. More... | |
| bool | isDisabled (const State &) const |
| Test whether this constraint is currently disabled in the supplied State. More... | |
| bool | isDisabledByDefault () const |
| Test whether this Constraint is disabled by default in which case it must be explicitly enabled before it will take effect. More... | |
| void | setDisabledByDefault (bool shouldBeDisabled) |
| Normally Constraints are enabled when defined and can be disabled later. More... | |
| operator ConstraintIndex () const | |
| This is an implicit conversion from Constraint to ConstraintIndex when needed. More... | |
| const SimbodyMatterSubsystem & | getMatterSubsystem () const |
| Get a const reference to the matter subsystem that contains this Constraint. More... | |
| SimbodyMatterSubsystem & | updMatterSubsystem () |
| Assuming you have writable access to this Constraint, get a writable reference to the containing matter subsystem. More... | |
| ConstraintIndex | getConstraintIndex () const |
| Get the ConstraintIndex that was assigned to this Constraint when it was added to the matter subsystem. More... | |
| bool | isInSubsystem () const |
| Test whether this Constraint is contained within a matter subsystem. More... | |
| bool | isInSameSubsystem (const MobilizedBody &mobod) const |
| Test whether the supplied MobilizedBody is in the same matter subsystem as this Constraint. More... | |
| int | getNumConstrainedBodies () const |
| Return the number of unique bodies directly restricted by this constraint. More... | |
| const MobilizedBody & | getMobilizedBodyFromConstrainedBody (ConstrainedBodyIndex consBodyIx) const |
| Return a const reference to the actual MobilizedBody corresponding to one of the Constrained Bodies included in the count returned by getNumConstrainedBodies(). More... | |
| const MobilizedBody & | getAncestorMobilizedBody () const |
| Return a const reference to the actual MobilizedBody which is serving as the Ancestor body for the constrained bodies in this Constraint. More... | |
| int | getNumConstrainedMobilizers () const |
| Return the number of unique mobilizers directly restricted by this Constraint. More... | |
| const MobilizedBody & | getMobilizedBodyFromConstrainedMobilizer (ConstrainedMobilizerIndex consMobilizerIx) const |
| Return a const reference to the actual MobilizedBody corresponding to one of the Constrained Mobilizers included in the count returned by getNumConstrainedMobilizers(). More... | |
| const SimbodyMatterSubtree & | getSubtree () const |
| Return a subtree object indicating which parts of the multibody tree are potentially affected by this Constraint. More... | |
| int | getNumConstrainedQ (const State &, ConstrainedMobilizerIndex) const |
| Return the number of constrainable generalized coordinates q associated with a particular constrained mobilizer. More... | |
| int | getNumConstrainedU (const State &, ConstrainedMobilizerIndex) const |
| Return the number of constrainable mobilities u associated with a particular constrained mobilizer. More... | |
| ConstrainedUIndex | getConstrainedUIndex (const State &, ConstrainedMobilizerIndex, MobilizerUIndex which) const |
| Return the index into the constrained mobilities u array corresponding to a particular mobility of the indicated ConstrainedMobilizer. More... | |
| ConstrainedQIndex | getConstrainedQIndex (const State &, ConstrainedMobilizerIndex, MobilizerQIndex which) const |
| Return the index into the constrained coordinates q array corresponding to a particular coordinate of the indicated ConstrainedMobilizer. More... | |
| int | getNumConstrainedQ (const State &) const |
| Return the sum of the number of coordinates q associated with each of the constrained mobilizers. More... | |
| int | getNumConstrainedU (const State &) const |
| Return the sum of the number of mobilities u associated with each of the constrained mobilizers. More... | |
| QIndex | getQIndexOfConstrainedQ (const State &state, ConstrainedQIndex consQIndex) const |
| Map one of this Constraint's constrained q's to the corresponding index within the matter subsystem's whole q vector. More... | |
| UIndex | getUIndexOfConstrainedU (const State &state, ConstrainedUIndex consUIndex) const |
| Map one of this Constraint's constrained U's (or mobilities) to the corresponding index within the matter subsystem's whole u vector. More... | |
| void | getNumConstraintEquationsInUse (const State &state, int &mp, int &mv, int &ma) const |
| Find out how many holonomic (position), nonholonomic (velocity), and acceleration-only constraint equations are currently being generated by this Constraint. More... | |
| void | getIndexOfMultipliersInUse (const State &state, MultiplierIndex &px0, MultiplierIndex &vx0, MultiplierIndex &ax0) const |
| Return the start of the blocks of multipliers (or acceleration errors) assigned to this Constraint. More... | |
| void | setMyPartInConstraintSpaceVector (const State &state, const Vector &myPart, Vector &constraintSpace) const |
| Set the part of a complete constraint-space vector that belongs to this constraint. More... | |
| void | getMyPartFromConstraintSpaceVector (const State &state, const Vector &constraintSpace, Vector &myPart) const |
| Get the part of a complete constraint-space vector that belongs to this constraint. More... | |
| Vector | getPositionErrorsAsVector (const State &) const |
| Get a Vector containing the position errors. More... | |
| Vector | calcPositionErrorFromQ (const State &, const Vector &q) const |
| Matrix | calcPositionConstraintMatrixP (const State &) const |
| Matrix | calcPositionConstraintMatrixPt (const State &) const |
| Matrix | calcPositionConstraintMatrixPNInv (const State &) const |
| void | calcConstraintForcesFromMultipliers (const State &, const Vector &lambda, Vector_< SpatialVec > &bodyForcesInA, Vector &mobilityForces) const |
| This operator calculates this constraint's body and mobility forces given the complete set of multipliers lambda for this Constraint. More... | |
| Vector | getVelocityErrorsAsVector (const State &) const |
| Get a Vector containing the velocity errors. More... | |
| Vector | calcVelocityErrorFromU (const State &, const Vector &u) const |
| Matrix | calcVelocityConstraintMatrixV (const State &) const |
| Matrix | calcVelocityConstraintMatrixVt (const State &) const |
| Vector | getAccelerationErrorsAsVector (const State &) const |
| Get a Vector containing the acceleration errors. More... | |
| Vector | calcAccelerationErrorFromUDot (const State &, const Vector &udot) const |
| Vector | getMultipliersAsVector (const State &) const |
| Get a Vector containing the Lagrange multipliers. More... | |
| void | getConstraintForcesAsVectors (const State &state, Vector_< SpatialVec > &bodyForcesInG, Vector &mobilityForces) const |
| Given a State realized through Acceleration stage, return the forces that were applied to the system by this Constraint, with body forces expressed in Ground. More... | |
| Vector_< SpatialVec > | getConstrainedBodyForcesAsVector (const State &state) const |
| For convenience, returns constrained body forces as the function return. More... | |
| Vector | getConstrainedMobilityForcesAsVector (const State &state) const |
| For convenience, returns constrained mobility forces as the function return. More... | |
| Real | calcPower (const State &state) const |
| Calculate the power being applied by this Constraint to the system. More... | |
| Matrix | calcAccelerationConstraintMatrixA (const State &) const |
| Matrix | calcAccelerationConstraintMatrixAt (const State &) const |
| void | setIsConditional (bool isConditional) |
| (Advanced) Mark this constraint as one that is only conditionally active. More... | |
| bool | isConditional () const |
| (Advanced) Get the value of the isConditional flag. More... | |
| Public Member Functions inherited from SimTK::PIMPLHandle< Constraint, ConstraintImpl, true > | |
| bool | isEmptyHandle () const |
| Returns true if this handle is empty, that is, does not refer to any implementation object. More... | |
| bool | isOwnerHandle () const |
| Returns true if this handle is the owner of the implementation object to which it refers. More... | |
| bool | isSameHandle (const Constraint &other) const |
| Determine whether the supplied handle is the same object as "this" PIMPLHandle. More... | |
| void | disown (Constraint &newOwner) |
| Give up ownership of the implementation to an empty handle. More... | |
| PIMPLHandle & | referenceAssign (const Constraint &source) |
| "Copy" assignment but with shallow (pointer) semantics. More... | |
| PIMPLHandle & | copyAssign (const Constraint &source) |
| This is real copy assignment, with ordinary C++ object ("value") semantics. More... | |
| void | clearHandle () |
| Make this an empty handle, deleting the implementation object if this handle is the owner of it. More... | |
| const ConstraintImpl & | getImpl () const |
| Get a const reference to the implementation associated with this Handle. More... | |
| ConstraintImpl & | updImpl () |
| Get a writable reference to the implementation associated with this Handle. More... | |
| int | getImplHandleCount () const |
| Return the number of handles the implementation believes are referencing it. More... | |
Additional Inherited Members | |
| Public Types inherited from SimTK::Constraint | |
| typedef Rod | ConstantDistance |
| Synonym for Rod constraint. More... | |
| typedef Ball | CoincidentPoints |
| Synonym for Ball constraint. More... | |
| typedef Ball | Spherical |
| Synonym for Ball constraint. More... | |
| typedef Weld | CoincidentFrames |
| Public Types inherited from SimTK::PIMPLHandle< Constraint, ConstraintImpl, true > | |
| typedef PIMPLHandle< Constraint, ConstraintImpl, PTR > | HandleBase |
| typedef HandleBase | ParentHandle |
| Protected Member Functions inherited from SimTK::PIMPLHandle< Constraint, ConstraintImpl, true > | |
| PIMPLHandle () | |
| The default constructor makes this an empty handle. More... | |
| PIMPLHandle (ConstraintImpl *p) | |
| This provides consruction of a handle referencing an existing implementation object. More... | |
| PIMPLHandle (const PIMPLHandle &source) | |
| The copy constructor makes either a deep (value) or shallow (reference) copy of the supplied source PIMPL object, based on whether this is a "pointer
semantics" (PTR=true) or "object (value) semantics" (PTR=false, default) class. More... | |
| ~PIMPLHandle () | |
| Note that the destructor is non-virtual. More... | |
| PIMPLHandle & | operator= (const PIMPLHandle &source) |
| Copy assignment makes the current handle either a deep (value) or shallow (reference) copy of the supplied source PIMPL object, based on whether this is a "pointer sematics" (PTR=true) or "object (value) semantics" (PTR=false, default) class. More... | |
| void | setImpl (ConstraintImpl *p) |
| Set the implementation for this empty handle. More... | |
| bool | hasSameImplementation (const Constraint &other) const |
| Determine whether the supplied handle is a reference to the same implementation object as is referenced by "this" PIMPLHandle. More... | |
Detailed Description
Constrain a single mobility to have a particular speed.
One non-holonomic constraint equation. Some mobility u is required to be at a particular value s.
Consider using the lock() or lockAt() feature of mobilizers (see MobilizedBody description) instead of this constraint; if applicable, locking is more efficient since it does not require adding a constraint equation to the system.
The assembly condition is the same as the run-time constraint: u must be set to s.
Constructor & Destructor Documentation
◆ ConstantSpeed() [1/3]
| SimTK::Constraint::ConstantSpeed::ConstantSpeed | ( | MobilizedBody & | mobilizer, |
| MobilizerUIndex | whichU, | ||
| Real | defaultSpeed | ||
| ) |
Construct a constant speed constraint on a particular mobility of the given mobilizer.
◆ ConstantSpeed() [2/3]
| SimTK::Constraint::ConstantSpeed::ConstantSpeed | ( | MobilizedBody & | mobilizer, |
| Real | defaultSpeed | ||
| ) |
Construct a constant speed constraint on the mobility of the given mobilizer, assuming there is only one mobility.
◆ ConstantSpeed() [3/3]
Default constructor creates an empty handle you can use to reference any existing ConstantSpeed Constraint.
Member Function Documentation
◆ getMobilizedBodyIndex()
| MobilizedBodyIndex SimTK::Constraint::ConstantSpeed::getMobilizedBodyIndex | ( | ) | const |
Return the index of the mobilized body to which this constant speed constraint is being applied (to one of its mobilities).
This is set on construction of the ConstantSpeed constraint.
◆ getWhichU()
| MobilizerUIndex SimTK::Constraint::ConstantSpeed::getWhichU | ( | ) | const |
Return the particular mobility whose generalized speed is controlled by this ConstantSpeed constraint.
This is set on construction.
◆ getDefaultSpeed()
| Real SimTK::Constraint::ConstantSpeed::getDefaultSpeed | ( | ) | const |
Return the default value for the speed to be enforced.
This is set on construction or via setDefaultSpeed(). This is used to initialize the speed when a default State is created, but it can be overriden by changing the value in the State using setSpeed().
◆ setDefaultSpeed()
| ConstantSpeed& SimTK::Constraint::ConstantSpeed::setDefaultSpeed | ( | Real | speed | ) |
Change the default value for the speed to be enforced by this constraint.
This is a topological change, meaning you'll have to call realizeTopology() on the containing System and obtain a new State before you can use it. If you just want to make a runtime change in the State, see setSpeed().
◆ setSpeed()
Override the default speed with this one whose value is stored in the given State.
This invalidates the Velocity stage in the state. Don't confuse this with setDefaultSpeed() – the value set here overrides that one.
◆ getSpeed()
Get the current value of the speed set point from the indicated State.
This is the value currently in effect, either from the default or from a previous call to setSpeed().
◆ getVelocityError()
Return the amount by which the given State fails to satisfy this ConstantSpeed constraint.
The state must already be realized through Stage::Velocity.
◆ getAccelerationError()
Return the amount by which the accelerations in the given State fail to satify the time derivative of this constraint (which must be zero).
The state must already be realized through Stage::Acceleration.
◆ getMultiplier()
Get the value of the Lagrange multiplier generated to satisfy this constraint.
For a ConstantSpeed constraint, that is the same as the generalized force although by convention constraint multipliers have the opposite sign from applied forces. The state must already be realized through Stage::Acceleration.
The documentation for this class was generated from the following file:
