A constant generalized force f (a scalar) applied to a mobility. More...

Inheritance diagram for SimTK::Force::MobilityConstantForce:

Public Member Functions
	MobilityConstantForce (GeneralForceSubsystem &forces, const MobilizedBody &mobod, MobilizerUIndex whichU, Real defaultForce)
	Add a MobilityConstantForce element to the indicated Subsystem. More...

	MobilityConstantForce (GeneralForceSubsystem &forces, const MobilizedBody &mobod, Real defaultForce)
	Alternate constructor signature for when the mobilizer has only a single generalized speed, in which case we'll use MobilizerUIndex(0). More...

	MobilityConstantForce ()
	Default constructor creates an empty handle. More...

MobilityConstantForce &	setDefaultForce (Real defaultForce)
	Provide a new value for the default generalied force to be applied by this force element. More...

Real	getDefaultForce () const
	Return the default value for the generalized force. More...

void	setForce (State &state, Real force) const
	Change the value of the generalized force that is stored in the given state; this may differ from the default value supplied at construction. More...

Real	getForce (const State &state) const
	Return the value for the generalized force that is stored in the given state. More...

Deprecated
Methods here are for backwards compatibility but have been replaced with better ones that you should use.
	MobilityConstantForce (GeneralForceSubsystem &forces, const MobilizedBody &mobod, int whichU, Real defaultForce)
	Deprecated: Alternate signature for backwards compatibility – for safety you should prefer using the other constructor signature that takes a MobilizerUIndex rather than a plain int. More...

Public Member Functions inherited from SimTK::Force
void	disable (State &) const
	Disable this force element, effectively removing it from the System for computational purposes (it is still using its ForceIndex, however). More...

void	enable (State &) const
	Enable this force element if it was previously disabled. More...

bool	isDisabled (const State &) const
	Test whether this force element is currently disabled in the supplied State. More...

void	setDisabledByDefault (bool shouldBeDisabled)
	Normally force elements are enabled when defined and can be disabled later. More...

bool	isDisabledByDefault () const
	Test whether this force element is disabled by default in which case it must be explicitly enabled before it will take effect. More...

void	calcForceContribution (const State &state, Vector_< SpatialVec > &bodyForces, Vector_< Vec3 > &particleForces, Vector &mobilityForces) const
	Calculate the force that would be applied by this force element if the given state were realized to Dynamics stage. More...

Real	calcPotentialEnergyContribution (const State &state) const
	Calculate the potential energy contribution that is made by this force element at the given state. More...

	Force ()
	Default constructor for Force handle base class does nothing. More...

	operator ForceIndex () const
	Implicit conversion to ForceIndex when needed. More...

const GeneralForceSubsystem &	getForceSubsystem () const
	Get the GeneralForceSubsystem of which this Force is an element. More...

ForceIndex	getForceIndex () const
	Get the index of this force element within its parent force subsystem. More...

Public Member Functions inherited from SimTK::PIMPLHandle< Force, ForceImpl, 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 Force &other) const
	Determine whether the supplied handle is the same object as "this" PIMPLHandle. More...

void	disown (Force &newOwner)
	Give up ownership of the implementation to an empty handle. More...

PIMPLHandle &	referenceAssign (const Force &source)
	"Copy" assignment but with shallow (pointer) semantics. More...

PIMPLHandle &	copyAssign (const Force &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 ForceImpl &	getImpl () const
	Get a const reference to the implementation associated with this Handle. More...

ForceImpl &	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::PIMPLHandle< Force, ForceImpl, true >
typedef PIMPLHandle< Force, ForceImpl, PTR >	HandleBase

typedef HandleBase	ParentHandle

Protected Member Functions inherited from SimTK::Force
	Force (ForceImpl *r)
	Use this in a derived Force handle class constructor to supply the concrete implementation object to be stored in the handle base. More...

Protected Member Functions inherited from SimTK::PIMPLHandle< Force, ForceImpl, true >
	PIMPLHandle ()
	The default constructor makes this an empty handle. More...

	PIMPLHandle (ForceImpl *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 (ForceImpl *p)
	Set the implementation for this empty handle. More...

bool	hasSameImplementation (const Force &other) const
	Determine whether the supplied handle is a reference to the same implementation object as is referenced by "this" PIMPLHandle. More...

Detailed Description

A constant generalized force f (a scalar) applied to a mobility.

The mobility here selects a generalized speed (u), not a generalized coordinate (q), and the meaning depends on the definition of the generalized speed. If that speed is a translation then this is a force; if a rotation then this is a torque; if anything more general then this is in compatible force units. This force does not contribute to the potential energy, so adding it to a system will cause energy not to be conserved unless you account for the power injected or dissipated here.

Constructor & Destructor Documentation

◆ MobilityConstantForce() [1/4]

SimTK::Force::MobilityConstantForce::MobilityConstantForce	(	GeneralForceSubsystem &	forces,
		const MobilizedBody &	mobod,
		MobilizerUIndex	whichU,
		Real	defaultForce
	)

Add a MobilityConstantForce element to the indicated Subsystem.

Parameters

forces	Subsystem to which this force should be added.
mobod	Mobilizer to which the force should be applied.
whichU	Index within mobod of the generalized speed u to which this force should be applied (first is zero).
defaultForce	Default value for the generalized force.

◆ MobilityConstantForce() [2/4]

SimTK::Force::MobilityConstantForce::MobilityConstantForce	(	GeneralForceSubsystem &	forces,
		const MobilizedBody &	mobod,
		Real	defaultForce
	)

inline

Alternate constructor signature for when the mobilizer has only a single generalized speed, in which case we'll use MobilizerUIndex(0).

See the other signature for documentation.

◆ MobilityConstantForce() [3/4]

SimTK::Force::MobilityConstantForce::MobilityConstantForce ( )

inline

Default constructor creates an empty handle.

◆ MobilityConstantForce() [4/4]

SimTK::Force::MobilityConstantForce::MobilityConstantForce	(	GeneralForceSubsystem &	forces,
		const MobilizedBody &	mobod,
		int	whichU,
		Real	defaultForce
	)

inline

Deprecated: Alternate signature for backwards compatibility – for safety you should prefer using the other constructor signature that takes a MobilizerUIndex rather than a plain int.

Member Function Documentation

◆ setDefaultForce()

MobilityConstantForce& SimTK::Force::MobilityConstantForce::setDefaultForce ( Real defaultForce )

Provide a new value for the default generalied force to be applied by this force element.

This is a topological change because it affects the value that the containing System's default state will have when realizeTopology() is called. This is for use during construction, not for during a simulation where you should be using setForce() to set the force in a State rather than in the System.

Parameters

defaultForce Default value for the generalized force.

Returns: A writable reference to this modified force element.

See also: setForce(), getDefaultForce()

◆ getDefaultForce()

Real SimTK::Force::MobilityConstantForce::getDefaultForce ( ) const

Return the default value for the generalized force.

This is normally set at construction but may have been changed with setDefaultForce().

See also: setDefaultForce(), getForce()

◆ setForce()

void SimTK::Force::MobilityConstantForce::setForce	(	State &	state,
		Real	force
	)		const

Change the value of the generalized force that is stored in the given state; this may differ from the default value supplied at construction.

Parameters

state	The State in which the bounds are changed.
force	The value of the generalized force to be applied when the state is subsequently used.

Changing this force invalidates Stage::Dynamics and above in the state since it affects force generation.

See also: getForce(), setDefaultForce()

◆ getForce()

Real SimTK::Force::MobilityConstantForce::getForce ( const State & state ) const

Return the value for the generalized force that is stored in the given state.

Note that this is not the same thing as the default force that was supplied on construction or with setDefaultForce().

See also: setForce(), getDefaultForce()

The documentation for this class was generated from the following file:

Force_MobilityConstantForce.h

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ MobilityConstantForce() [1/4]

◆ MobilityConstantForce() [2/4]

◆ MobilityConstantForce() [3/4]

◆ MobilityConstantForce() [4/4]

Member Function Documentation

◆ setDefaultForce()

◆ getDefaultForce()

◆ setForce()

◆ getForce()