Detailed Description

template<typename T>
class drake::multibody::FixedOffsetFrame< T >

FixedOffsetFrame represents a material frame F whose pose is fixed with respect to a parent material frame P.

The pose offset is given by a spatial transform X_PF, which is constant after construction. For instance, we could rigidly attach a frame F to move with a rigid body B at a fixed pose X_BF, where B is the RigidBodyFrame associated with body B. Thus, the World frame pose X_WF of a FixedOffsetFrame F depends only on the World frame pose X_WP of its parent P, and the constant pose X_PF, with X_WF=X_WP*X_PF.

For more information about spatial transforms, see Spatial Pose and Transform.

Template Parameters

T	The scalar type, which must be one of the default scalars.

#include <drake/multibody/tree/fixed_offset_frame.h>

Public Member Functions
	FixedOffsetFrame (const std::string &name, const Frame< T > &P, const math::RigidTransform< double > &X_PF, std::optional< ModelInstanceIndex > model_instance={})
	Creates a material Frame F whose pose is fixed with respect to its parent material Frame P. More...

	FixedOffsetFrame (const std::string &name, const RigidBody< T > &bodyB, const math::RigidTransform< double > &X_BF)
	Creates a material Frame F whose pose is fixed with respect to the RigidBodyFrame B of the given RigidBody, which serves as F's parent frame. More...

	~FixedOffsetFrame () override

void	SetPoseInParentFrame (systems::Context< T > *context, const math::RigidTransform< T > &X_PF) const
	Sets the pose of `this` frame F in its parent frame P. More...

math::RigidTransform< T >	GetPoseInParentFrame (const systems::Context< T > &context) const
	Returns the rigid transform X_PF that characterizes `this` frame F's pose in its parent frame P. More...

math::RigidTransform< T >	GetFixedPoseInBodyFrame () const override

math::RotationMatrix< T >	GetFixedRotationMatrixInBodyFrame () const override

const Frame< T > &	parent_frame () const

Does not allow copy, move, or assignment
	FixedOffsetFrame (const FixedOffsetFrame &)=delete

FixedOffsetFrame &	operator= (const FixedOffsetFrame &)=delete

	FixedOffsetFrame (FixedOffsetFrame &&)=delete

FixedOffsetFrame &	operator= (FixedOffsetFrame &&)=delete

Public Member Functions inherited from Frame< T >
	~Frame () override

FrameIndex	index () const
	Returns this element's unique index. More...

const RigidBody< T > &	body () const
	Returns a const reference to the body associated to this Frame. More...

bool	is_world_frame () const
	Returns true if `this` is the world frame. More...

bool	is_body_frame () const
	Returns true if `this` is the body frame. More...

const std::string &	name () const
	Returns the name of this frame. The name will never be empty. More...

ScopedName	scoped_name () const
	Returns scoped name of this frame. More...

const math::RigidTransform< T > &	EvalPoseInBodyFrame (const systems::Context< T > &context) const
	Returns a reference to the body-relative pose X_BF giving the pose of this Frame with respect to its body's RigidBodyFrame. More...

math::RigidTransform< T >	CalcPoseInBodyFrame (const systems::Context< T > &context) const
	Returns the pose `X_BF` of `this` frame F in the body frame B associated with this frame. More...

math::RotationMatrix< T >	CalcRotationMatrixInBodyFrame (const systems::Context< T > &context) const
	Returns the rotation matrix `R_BF` that relates body frame B to `this` frame F (B is the body frame to which `this` frame F is attached). More...

math::RigidTransform< T >	CalcOffsetPoseInBody (const systems::Context< T > &context, const math::RigidTransform< T > &X_FQ) const
	Given the offset pose `X_FQ` of a frame Q in `this` frame F, this method computes the pose `X_BQ` of frame Q in the body frame B to which this frame is attached. More...

math::RotationMatrix< T >	CalcOffsetRotationMatrixInBody (const systems::Context< T > &context, const math::RotationMatrix< T > &R_FQ) const
	Calculates and returns the rotation matrix `R_BQ` that relates body frame B to frame Q via `this` intermediate frame F, i.e., `R_BQ = R_BF * R_FQ` (B is the body frame to which `this` frame F is attached). More...

virtual math::RigidTransform< T >	GetFixedOffsetPoseInBody (const math::RigidTransform< T > &X_FQ) const
	Variant of CalcOffsetPoseInBody() that given the offset pose `X_FQ` of a frame Q in `this` frame F, returns the pose `X_BQ` of frame Q in the body frame B to which this frame is attached. More...

virtual math::RotationMatrix< T >	GetFixedRotationMatrixInBody (const math::RotationMatrix< T > &R_FQ) const
	Calculates and returns the rotation matrix `R_BQ` that relates body frame B to frame Q via `this` intermediate frame F, i.e., `R_BQ = R_BF * R_FQ` (B is the body frame to which `this` frame F is attached). More...

math::RigidTransform< T >	CalcPoseInWorld (const systems::Context< T > &context) const
	Computes and returns the pose `X_WF` of `this` frame F in the world frame W as a function of the state of the model stored in `context`. More...

math::RigidTransform< T >	CalcPose (const systems::Context< T > &context, const Frame< T > &frame_M) const
	Computes and returns the pose `X_MF` of `this` frame F in measured in `frame_M` as a function of the state of the model stored in `context`. More...

math::RotationMatrix< T >	CalcRotationMatrix (const systems::Context< T > &context, const Frame< T > &frame_M) const
	Calculates and returns the rotation matrix `R_MF` that relates `frame_M` and `this` frame F as a function of the state stored in `context`. More...

math::RotationMatrix< T >	CalcRotationMatrixInWorld (const systems::Context< T > &context) const
	Calculates and returns the rotation matrix `R_WF` that relates the world frame W and `this` frame F as a function of the state stored in `context`. More...

const Vector3< T > &	EvalAngularVelocityInWorld (const systems::Context< T > &context) const
	Evaluates `this` frame F's angular velocity measured and expressed in the world frame W. More...

Vector3< T >	CalcAngularVelocity (const systems::Context< T > &context, const Frame< T > &measured_in_frame, const Frame< T > &expressed_in_frame) const
	Calculates `this` frame F's angular velocity measured in a frame M, expressed in a frame E. More...

SpatialVelocity< T >	CalcSpatialVelocityInWorld (const systems::Context< T > &context) const
	Calculates `this` frame F's spatial velocity measured and expressed in the world frame W. More...

SpatialVelocity< T >	CalcSpatialVelocity (const systems::Context< T > &context, const Frame< T > &frame_M, const Frame< T > &frame_E) const
	Calculates `this` frame F's spatial velocity measured in a frame M, expressed in a frame E. More...

SpatialVelocity< T >	CalcRelativeSpatialVelocityInWorld (const systems::Context< T > &context, const Frame< T > &other_frame) const
	Calculates `this` frame C's spatial velocity relative to another frame B, measured and expressed in the world frame W. More...

SpatialVelocity< T >	CalcRelativeSpatialVelocity (const systems::Context< T > &context, const Frame< T > &other_frame, const Frame< T > &measured_in_frame, const Frame< T > &expressed_in_frame) const
	Calculates `this` frame C's spatial velocity relative to another frame B, measured in a frame M, expressed in a frame E. More...

SpatialAcceleration< T >	CalcSpatialAccelerationInWorld (const systems::Context< T > &context) const
	Calculates `this` frame F's spatial acceleration measured and expressed in the world frame W. More...

SpatialAcceleration< T >	CalcSpatialAcceleration (const systems::Context< T > &context, const Frame< T > &measured_in_frame, const Frame< T > &expressed_in_frame) const
	Calculates `this` frame F's spatial acceleration measured in a frame M, expressed in a frame E. More...

SpatialAcceleration< T >	CalcRelativeSpatialAccelerationInWorld (const systems::Context< T > &context, const Frame< T > &other_frame) const
	Calculates `this` frame C's spatial acceleration relative to another frame B, measured and expressed in the world frame W. More...

SpatialAcceleration< T >	CalcRelativeSpatialAcceleration (const systems::Context< T > &context, const Frame< T > &other_frame, const Frame< T > &measured_in_frame, const Frame< T > &expressed_in_frame) const
	Calculates `this` frame C's spatial acceleration relative to another frame B, measured in a frame M, expressed in a frame E. More...

template<typename ToScalar >
std::unique_ptr< Frame< ToScalar > >	CloneToScalar (const internal::MultibodyTree< ToScalar > &tree_clone) const
	(Advanced) NVI to DoCloneToScalar() templated on the scalar type of the new clone to be created. More...

std::unique_ptr< Frame< T > >	ShallowClone () const
	(Internal use only) Returns a shallow clone (i.e., dependent elements such as bodies are aliased, not copied) that is not associated with any MbT (so the assigned index, if any, is discarded). More...

	Frame (const Frame &)=delete

Frame &	operator= (const Frame &)=delete

	Frame (Frame &&)=delete

Frame &	operator= (Frame &&)=delete

void	set_body_pose_index_in_cache (int body_pose_index)
	(Internal use only) A Frame's pose-in-parent X_PF can be parameterized, the parent's pose may also be parameterized, and so on. More...

int	get_body_pose_index_in_cache () const
	(Internal use only) Retrieve this Frame's body pose index in the cache. More...

const math::RigidTransform< T > &	get_X_BF (const internal::FrameBodyPoseCache< T > &frame_body_poses) const
	(Internal use only) Given an already up-to-date frame body pose cache, extract X_BF for this Frame from it. More...

const math::RigidTransform< T > &	get_X_FB (const internal::FrameBodyPoseCache< T > &frame_body_poses) const
	(Internal use only) Given an already up-to-date frame body pose cache, extract X_FB (=X_BF⁻¹) for this Frame from it. More...

bool	is_X_BF_identity (const internal::FrameBodyPoseCache< T > &frame_body_poses) const
	(Internal use only) Given an already up-to-date frame body pose cache, returns whether X_BF (and thus X_FB) is exactly identity. More...

Public Member Functions inherited from MultibodyElement< T >
virtual	~MultibodyElement ()

ModelInstanceIndex	model_instance () const
	Returns the ModelInstanceIndex of the model instance to which this element belongs. More...

template<typename = void>
const MultibodyPlant< T > &	GetParentPlant () const
	Returns the MultibodyPlant that owns this MultibodyElement. More...

void	DeclareParameters (internal::MultibodyTreeSystem< T > *tree_system)
	Declares MultibodyTreeSystem Parameters at MultibodyTreeSystem::Finalize() time. More...

void	SetDefaultParameters (systems::Parameters< T > *parameters) const
	Sets default values of parameters belonging to each MultibodyElement in `parameters` at a call to MultibodyTreeSystem::SetDefaultParameters(). More...

void	DeclareDiscreteState (internal::MultibodyTreeSystem< T > *tree_system)
	Declares MultibodyTreeSystem discrete states. More...

void	DeclareCacheEntries (internal::MultibodyTreeSystem< T > *tree_system)
	(Advanced) Declares all cache entries needed by this element. More...

bool	is_ephemeral () const
	Returns `true` if this MultibodyElement was added during Finalize() rather than something a user added. More...

void	set_is_ephemeral (bool is_ephemeral)
	(Internal use only) Sets the `is_ephemeral` flag to the indicated value. More...

	MultibodyElement (const MultibodyElement &)=delete

MultibodyElement &	operator= (const MultibodyElement &)=delete

	MultibodyElement (MultibodyElement &&)=delete

MultibodyElement &	operator= (MultibodyElement &&)=delete

Protected Member Functions
std::unique_ptr< Frame< double > >	DoCloneToScalar (const internal::MultibodyTree< double > &tree_clone) const override

std::unique_ptr< Frame< AutoDiffXd > >	DoCloneToScalar (const internal::MultibodyTree< AutoDiffXd > &tree_clone) const override

std::unique_ptr< Frame< symbolic::Expression > >	DoCloneToScalar (const internal::MultibodyTree< symbolic::Expression > &) const override

std::unique_ptr< Frame< T > >	DoShallowClone () const override
	NVI for ShallowClone(). More...

math::RigidTransform< T >	DoCalcPoseInBodyFrame (const systems::Parameters< T > &parameters) const override

math::RotationMatrix< T >	DoCalcRotationMatrixInBodyFrame (const systems::Parameters< T > &parameters) const override

Protected Member Functions inherited from Frame< T >
	Frame (const std::string &name, const RigidBody< T > &body, std::optional< ModelInstanceIndex > model_instance={})
	Only derived classes can use this constructor. More...

virtual math::RigidTransform< T >	DoCalcOffsetPoseInBody (const systems::Parameters< T > &parameters, const math::RigidTransform< T > &X_FQ) const

virtual math::RotationMatrix< T >	DoCalcOffsetRotationMatrixInBody (const systems::Parameters< T > &parameters, const math::RotationMatrix< T > &R_FQ) const

Protected Member Functions inherited from MultibodyElement< T >
	MultibodyElement ()
	Default constructor made protected so that sub-classes can still declare their default constructors if they need to. More...

	MultibodyElement (ModelInstanceIndex model_instance)
	Constructor which allows specifying a model instance. More...

	MultibodyElement (ModelInstanceIndex model_instance, int64_t index)
	Both the model instance and element index are specified. More...

template<typename ElementIndexType >
ElementIndexType	index_impl () const
	Returns this element's unique index. More...

template<typename ElementOrdinalType = int64_t>
ElementOrdinalType	ordinal_impl () const
	Returns this element's unique ordinal. More...

const internal::MultibodyTree< T > &	get_parent_tree () const
	Returns a constant reference to the parent MultibodyTree that owns this element. More...

const internal::MultibodyTreeSystem< T > &	GetParentTreeSystem () const
	Returns a constant reference to the parent MultibodyTreeSystem that owns the parent MultibodyTree that owns this element. More...

void	SetTopology ()
	(Internal use only) Gives MultibodyElement-derived objects the opportunity to set data members that depend on topology and coordinate assignments having been finalized. More...

virtual void	DoDeclareDiscreteState (internal::MultibodyTreeSystem< T > *)
	Implementation of the NVI DeclareDiscreteState(). More...

virtual void	DoDeclareCacheEntries (internal::MultibodyTreeSystem< T > *)
	Derived classes must override this method to declare cache entries needed by `this` element. More...

systems::NumericParameterIndex	DeclareNumericParameter (internal::MultibodyTreeSystem< T > *tree_system, const systems::BasicVector< T > &model_vector)
	To be used by MultibodyElement-derived objects when declaring parameters in their implementation of DoDeclareParameters(). More...

systems::AbstractParameterIndex	DeclareAbstractParameter (internal::MultibodyTreeSystem< T > *tree_system, const AbstractValue &model_value)
	To be used by MultibodyElement-derived objects when declaring parameters in their implementation of DoDeclareParameters(). More...

systems::DiscreteStateIndex	DeclareDiscreteState (internal::MultibodyTreeSystem< T > *tree_system, const VectorX< T > &model_value)
	To be used by MultibodyElement-derived objects when declaring discrete states in their implementation of DoDeclareDiscreteStates(). More...

systems::CacheEntry &	DeclareCacheEntry (internal::MultibodyTreeSystem< T > *tree_system, std::string description, systems::ValueProducer value_producer, std::set< systems::DependencyTicket > prerequisites_of_calc)
	To be used by MultibodyElement-derived objects when declaring cache entries in their implementation of DoDeclareCacheEntries(). More...

bool	has_parent_tree () const
	Returns true if this multibody element has a parent tree, otherwise false. More...

Constructor & Destructor Documentation

◆ FixedOffsetFrame() [1/4]

FixedOffsetFrame ( const FixedOffsetFrame< T > & )

delete

◆ FixedOffsetFrame() [2/4]

FixedOffsetFrame ( FixedOffsetFrame< T > && )

delete

◆ FixedOffsetFrame() [3/4]

FixedOffsetFrame	(	const std::string &	name,
		const Frame< T > &	P,
		const math::RigidTransform< double > &	X_PF,
		std::optional< ModelInstanceIndex >	model_instance = `{}`
	)

Creates a material Frame F whose pose is fixed with respect to its parent material Frame P.

The pose is given by a spatial transform X_PF; see class documentation for more information.

Parameters

[in]	name	The name of this frame. Cannot be empty.
[in]	P	The frame to which this frame is attached with a fixed pose.
[in]	X_PF	The default transform giving the pose of F in P, therefore only the value (as a RigidTransform<double>) is provided.
[in]	model_instance	The model instance to which this frame belongs to. If unspecified, will use P.model_instance().

◆ FixedOffsetFrame() [4/4]

FixedOffsetFrame	(	const std::string &	name,
		const RigidBody< T > &	bodyB,
		const math::RigidTransform< double > &	X_BF
	)

Creates a material Frame F whose pose is fixed with respect to the RigidBodyFrame B of the given RigidBody, which serves as F's parent frame.

The pose is given by a RigidTransform X_BF; see class documentation for more information.

Parameters

[in]	name	The name of this frame. Cannot be empty.
[in]	bodyB	The body whose RigidBodyFrame B is to be F's parent frame.
[in]	X_BF	The transform giving the pose of F in B.

◆ ~FixedOffsetFrame()

~FixedOffsetFrame ( )

override

Member Function Documentation

◆ DoCalcPoseInBodyFrame()

math::RigidTransform<T> DoCalcPoseInBodyFrame ( const systems::Parameters< T > & parameters ) const

overrideprotectedvirtual

Implements Frame< T >.

◆ DoCalcRotationMatrixInBodyFrame()

math::RotationMatrix<T> DoCalcRotationMatrixInBodyFrame ( const systems::Parameters< T > & parameters ) const

overrideprotectedvirtual

Implements Frame< T >.

◆ DoCloneToScalar() [1/3]

std::unique_ptr<Frame<double> > DoCloneToScalar ( const internal::MultibodyTree< double > & tree_clone ) const

overrideprotectedvirtual

Precondition: The parent frame to this frame already has a clone in tree_clone.

Implements Frame< T >.

◆ DoCloneToScalar() [2/3]

std::unique_ptr<Frame<AutoDiffXd> > DoCloneToScalar ( const internal::MultibodyTree< AutoDiffXd > & tree_clone ) const

overrideprotectedvirtual

Precondition: The parent frame to this frame already has a clone in tree_clone.

Implements Frame< T >.

◆ DoCloneToScalar() [3/3]

std::unique_ptr<Frame<symbolic::Expression> > DoCloneToScalar ( const internal::MultibodyTree< symbolic::Expression > & ) const

overrideprotectedvirtual

Implements Frame< T >.

◆ DoShallowClone()

std::unique_ptr<Frame<T> > DoShallowClone ( ) const

overrideprotectedvirtual

NVI for ShallowClone().

Reimplemented from Frame< T >.

◆ GetFixedPoseInBodyFrame()

math::RigidTransform<T> GetFixedPoseInBodyFrame ( ) const

overridevirtual

Returns: The default fixed pose in the body frame.

Reimplemented from Frame< T >.

◆ GetFixedRotationMatrixInBodyFrame()

math::RotationMatrix<T> GetFixedRotationMatrixInBodyFrame ( ) const

overridevirtual

Returns: The default rotation matrix of this fixed pose in the body frame.

Reimplemented from Frame< T >.

◆ GetPoseInParentFrame()

math::RigidTransform<T> GetPoseInParentFrame ( const systems::Context< T > & context ) const

Returns the rigid transform X_PF that characterizes this frame F's pose in its parent frame P.

Parameters

[in] context of the multibody plant associated with this frame.

◆ operator=() [1/2]

FixedOffsetFrame& operator= ( const FixedOffsetFrame< T > & )

delete

◆ operator=() [2/2]

FixedOffsetFrame& operator= ( FixedOffsetFrame< T > && )

delete

◆ parent_frame()

const Frame<T>& parent_frame ( ) const

Returns: The parent frame to which this frame is attached.

◆ SetPoseInParentFrame()

void SetPoseInParentFrame	(	systems::Context< T > *	context,
		const math::RigidTransform< T > &	X_PF
	)		const

Sets the pose of this frame F in its parent frame P.

Parameters

[in,out]	context	of the multibody plant associated with this frame.
[in]	X_PF	Rigid transform that characterizes `this` frame F's pose (orientation and position) in its parent frame P.

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

drake/multibody/tree/fixed_offset_frame.h

Detailed Description

template<typename T> class drake::multibody::FixedOffsetFrame< T >

Public Member Functions

Protected Member Functions

Constructor & Destructor Documentation

◆ FixedOffsetFrame() [1/4]

◆ FixedOffsetFrame() [2/4]

◆ FixedOffsetFrame() [3/4]

◆ FixedOffsetFrame() [4/4]

◆ ~FixedOffsetFrame()

Member Function Documentation

◆ DoCalcPoseInBodyFrame()

◆ DoCalcRotationMatrixInBodyFrame()

◆ DoCloneToScalar() [1/3]

◆ DoCloneToScalar() [2/3]

◆ DoCloneToScalar() [3/3]

◆ DoShallowClone()

◆ GetFixedPoseInBodyFrame()

◆ GetFixedRotationMatrixInBodyFrame()

◆ GetPoseInParentFrame()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ parent_frame()

◆ SetPoseInParentFrame()

template<typename T>
class drake::multibody::FixedOffsetFrame< T >