Robot Dynamics Library: Reference Frame

Classes
class	RobotDynamics::ReferenceFrame
	ReferenceFrame object used to tell what frame objects are expressed in. Every ReferenceFrame has a pointer to its parent ReferenceFrame. This parent frame is NOT allowed to be nullptr. The ONLY ReferenceFrame that is allowed to have parentFrame=nullptr is the world frame. There is only one world frame and it can be accessed by the static method ReferenceFrame::getWorldFrame() which will return a shared_ptr to the world frame. This class and its implementation are an adaptation of ReferenceFrame.java by Jerry Pratt and the IHMC Robotics Group. More...

class	RobotDynamics::FixedReferenceFrame

class	RobotDynamics::ReferenceFrameException
	A custom exception for frame operations. More...

class	RobotDynamics::FrameObject
	An interface that objects with a ReferenceFrame extend to inherit the FrameObject::changeFrame method. More...

class	RobotDynamics::Math::FrameOrientation
	A Frame object that represents an orientation(quaternion) relative to a reference frame. More...

class	RobotDynamics::Math::FramePoint
	A FramePoint is a 3D point that is expressed in a ReferenceFrame. To change the ReferenceFrame a FramePoint is expressed in, you may call the inhereted FrameObject::changeFrame method and supply it a pointer to the ReferenceFrame you wish to have the FramePoint expressed in. This class and its implementation are an adaptation of FramePoint.java by Jerry Pratt and the IHMC Robotics Group. More...

class	RobotDynamics::Math::FrameVector
	A FrameVector is a 3D vector with a ReferenceFrame, and all operations between FrameVectors and other frame objects will perform runtime checks that objects are expressed in the same frames. This class and its implementation are an adaptation of FrameVector.java by Jerry Pratt and the IHMC Robotics Group. More...

class	RobotDynamics::Math::FrameVectorPair
	A FrameVector is a pair of 3D vector with a ReferenceFrame. More...

class	RobotDynamics::Math::SpatialAcceleration
	SpatialAcceleration. For clarity, the ReferenceFrames are stated as follows. A spatial acceleration is the acceleration of the SpatialAcceleration::bodyFrame with respect to the SpatialAcceleration::baseFrame expressed in the SpatialAcceleration::expressedInFrame. More...

class	RobotDynamics::Math::SpatialForce
	A SpatialForce is a spatial vector with the angular part being three moments and the linear part being 3 linear forces. More...

class	RobotDynamics::Math::SpatialMomentum
	A SpatialMomentum is a Momentum expressed in a RobotDynamics::ReferenceFrame. The angular portion of the vector is referred to as and the linear portion as . More...

class	RobotDynamics::Math::SpatialMotion
	A SpatialMotion vector is a MotionVector with a RobotDynamics::ReferenceFrame it is expressed in. This allows for runtime checks that frame rules are obeyed and makes it easy to change the frame the metion vector is expressed in. As with a SpatialAcceleration, a SpatialMotion vector is the spatial velocity of a SpatialMotion::bodyFrame relative to a SpatialMotion::baseFrame and is expressed in RobotDynamics::FrameObject::referenceFrame. More...

class	RobotDynamics::Math::SpatialInertia
	A Math::SpatialInertia is a RigidBodyInertia explicitly expressed in a RobotDynamics::ReferenceFrame. The frame a Math::SpatialInertia is expressed in can be changed by calling RobotDynamics::FrameObject::changeFrame. More...

Typedefs
typedef std::shared_ptr< ReferenceFrame >	RobotDynamics::ReferenceFramePtr

typedef std::shared_ptr< FixedReferenceFrame >	RobotDynamics::FixedReferenceFramePtr

typedef std::vector< ReferenceFramePtr >	RobotDynamics::ReferenceFramePtrV

typedef std::vector< FixedReferenceFramePtr >	RobotDynamics::FixedReferenceFramePtrV

Functions
RobotDynamics::Math::FramePoint	RobotDynamics::HydroUtils::updateCenterOfBuoyancyFrame (Model &model, const Math::VectorNd &q, bool update_kinematics=true)
	Computes the center of buoyancy and updates the center of buoyancy reference frame of the model. More...

RobotDynamics::Math::FramePoint	RobotDynamics::HydroUtils::updateCenterOfBuoyancyFrame (Model &model, const Math::VectorNd &q, const Math::Quaternion &orientation, bool update_kinematics=true)
	Computes the center of buoyancy and updates the center of buoyancy reference frame of the model. More...

RobotDynamics::Math::FramePoint	RobotDynamics::HydroUtils::updateCenterOfBuoyancyFrame (Model &model, const Math::VectorNd &q, const Math::Vector3d &euler_ypr, bool update_kinematics=true)
	Computes the center of buoyancy and updates the center of buoyancy reference frame of the model. More...

void	RobotDynamics::HydroUtils::updateCenterOfBuoyancyFrame (Model &model, const Math::Vector3d &p_cob)
	Updates the center of buoyancy frame of the robot be at location p_com and aligned with world frame. More...

void	RobotDynamics::HydroUtils::updateCenterOfBuoyancyFrame (Model &model, const Math::Vector3d &p_cob, const Math::Quaternion &orientation)
	Updates the center of buoyancy frame of the robot be at location p_com and aligned with world frame. More...

void	RobotDynamics::HydroUtils::updateCenterOfBuoyancyFrame (Model &model, const Math::Vector3d &p_cob, const Math::Vector3d &euler_ypr)
	Updates the center of buoyancy frame of the robot be at location p_com and to have orientation defined by the yaw/pitch/roll angles in euler_ypr argument. The euler_ypr argument is optional and if not provided the center of buoyancy reference frame will be aligned with world. More...

void	RobotDynamics::Utils::calcCenterOfMass (Model &model, const Math::VectorNd &q, const Math::VectorNd &qdot, Math::FramePoint &com, Math::FrameVector &com_velocity, Math::FrameVector *angular_momentum=nullptr, bool update_kinematics=true)
	Computes the Center of Mass (COM) and optionally its linear velocity and/or angular momentum. More...

void	RobotDynamics::Utils::calcCenterOfMass (Model &model, const Math::VectorNd &q, const Math::VectorNd &qdot, Math::FramePoint &com, Math::FrameVector *com_velocity=nullptr, bool update_kinematics=true)
	Computes the Center of Mass (COM) and optionally its linear velocity. More...

RobotDynamics::Math::FramePoint	RobotDynamics::Utils::updateCenterOfMassFrame (Model &model, const Math::VectorNd &q, bool update_kinematics=true)
	Computes the center of mass and updates the center of mass reference frame of the model. More...

RobotDynamics::Math::FramePoint	RobotDynamics::Utils::updateCenterOfMassFrame (Model &model, const Math::VectorNd &q, const Math::Vector3d &euler_ypr, bool update_kinematics=true)
	Computes the center of mass and updates the center of mass reference frame of the model. More...

RobotDynamics::Math::FramePoint	RobotDynamics::Utils::updateCenterOfMassFrame (Model &model, const Math::VectorNd &q, const Math::Quaternion &orientation, bool update_kinematics=true)
	Computes the center of mass and updates the center of mass reference frame of the model. More...

void	RobotDynamics::Utils::updateCenterOfMassFrame (Model &model, const Math::Vector3d &p_com)
	Updates the center of mass frame of the robot be at location p_com, aligned with world frame. More...

void	RobotDynamics::Utils::updateCenterOfMassFrame (Model &model, const Math::Vector3d &p_com, const Math::Vector3d &euler_ypr)
	Updates the center of mass frame of the robot be at location p_com and to have orientation defined by the yaw/pitch/roll angles in euler_ypr argument. The euler_ypr argument is optional and if not provided the center of mass reference frame will be aligned with world. More...

void	RobotDynamics::Utils::updateCenterOfMassFrame (Model &model, const Math::Vector3d &p_com, const Math::Quaternion &orientation)
	Updates the center of mass frame of the robot be at location p_com and to have orientation defined by the orientation argument. The quaternion argument is optional and if not provided the center of mass reference frame will be aligned with world. More...

	RobotDynamics::ReferenceFrame::ReferenceFrame (const ReferenceFrame &referenceFrameToCopy)
	Copy constructor. More...

	RobotDynamics::ReferenceFrame::ReferenceFrame (const std::string &frameName, ReferenceFramePtr parentFrame, const RobotDynamics::Math::SpatialTransform &transformFromParent, bool isBodyFrame, unsigned int movableBodyId)
	Constructor. More...

	RobotDynamics::ReferenceFrame::ReferenceFrame ()
	Empty constructor. All contained ptrs will be initialize to nullptr. More...

ReferenceFrame *	RobotDynamics::ReferenceFrame::getRootFrame ()

virtual	RobotDynamics::ReferenceFrame::~ReferenceFrame ()
	Destructor. More...

void	RobotDynamics::ReferenceFrame::update ()
	Recalculates this frames ReferenceFrame::transformToRoot and ReferenceFrame::inverseTransformToRoot which are used by FrameObject::changeFrame to change the ReferenceFrame FrameObjects are expressed in. If you create a ReferenceFrame you MUST call update every tic each time the frames ReferenceFrame::transformFromParent changes. Each time ReferenceFrame::setTransformFromParent changes, you need to call ReferenceFrame::transformFromParent before you call ReferenceFrame::update(). More...

void	RobotDynamics::ReferenceFrame::getTransformToDesiredFrame (RobotDynamics::Math::SpatialTransform &transformToPack, ReferenceFramePtr desiredFrame)
	Get the spatial transform from this frame to desiredFrame and store it in transformToPack. More...

virtual RobotDynamics::Math::SpatialTransform	RobotDynamics::ReferenceFrame::getTransformToDesiredFrame (ReferenceFramePtr desiredFrame)
	Get the spatial transform from this frame to desiredFrame and store it in transformToPack. More...

void	RobotDynamics::ReferenceFrame::verifyFramesHaveSameRoot (ReferenceFramePtr frame)
	Check if two frames have the same roots. More...

void	RobotDynamics::ReferenceFrame::setTransformFromParent (const RobotDynamics::Math::SpatialTransform &transformFromParent)
	Set a frames ReferenceFrame::transformToParent. For frames connected by a joint, this needs to be updated every tic BEFORE calling the ReferenceFrame::update method. More...

void	RobotDynamics::ReferenceFrame::checkReferenceFramesMatch (ReferenceFramePtr referenceFrame) const
	Check if the argument ReferenceFrame equals this. More...

void	RobotDynamics::ReferenceFrame::checkReferenceFramesMatch (ReferenceFrame *referenceFrame) const

virtual RobotDynamics::Math::SpatialTransform	RobotDynamics::ReferenceFrame::getTransformToRoot ()
	Get this frames ReferenceFrame::transformToRoot. More...

virtual RobotDynamics::Math::SpatialTransform	RobotDynamics::ReferenceFrame::getInverseTransformToRoot ()
	Get this frames ReferenceFrame::inverseTransformToRoot. More...

ReferenceFramePtr	RobotDynamics::ReferenceFrame::getParentFrame ()
	get a pointer to this frames parent More...

std::string	RobotDynamics::ReferenceFrame::getName () const
	Get the frame name. More...

static ReferenceFramePtr	RobotDynamics::ReferenceFrame::createARootFrame (const std::string &frameName)
	Creates a root frame with ReferenceFrame::parentFrame=nullptr. More...

static ReferenceFramePtr	RobotDynamics::ReferenceFrame::getWorldFrame ()
	Get a pointer to the world frame. More...

RobotDynamics::Math::SpatialTransform	RobotDynamics::ReferenceFrame::getTransformFromParent ()
	Get spatial transform from parent to this frame. More...

RobotDynamics::Math::SpatialTransform	RobotDynamics::ReferenceFrame::getTransformToParent ()
	Get spatial transform this frame to its parent. More...

bool	RobotDynamics::ReferenceFrame::getIsWorldFrame () const
	Get a boolean telling if this frame is the world frame. More...

unsigned int	RobotDynamics::ReferenceFrame::getMovableBodyId () const
	Get the ID of the movable body this frame is attached to. More...

bool	RobotDynamics::ReferenceFrame::getIsBodyFrame () const
	Get boolean telling if this frame is a body frame or not. If it is a body frame, A pointer to this frame would be stored in Model::bodyFrames vector. More...

ReferenceFrame &	RobotDynamics::ReferenceFrame::operator= (const ReferenceFrame &other)

	RobotDynamics::ReferenceFrame::ReferenceFrame (const std::string &frameName, bool isWorldFrame, unsigned int movableBodyId, bool isBodyFrame)

static ReferenceFramePtr	RobotDynamics::ReferenceFrame::createAWorldFrame (const std::string &frameName="world")
	Helper method to create a world frame. More...

	RobotDynamics::FixedReferenceFrame::FixedReferenceFrame (const FixedReferenceFrame &)=delete

void	RobotDynamics::FixedReferenceFrame::operator= (const FixedReferenceFrame &)=delete

	RobotDynamics::FixedReferenceFrame::FixedReferenceFrame (const std::string &frameName, ReferenceFramePtr parentFrame, const RobotDynamics::Math::SpatialTransform &transformFromParent, unsigned int movableBodyId)

virtual	RobotDynamics::FixedReferenceFrame::~FixedReferenceFrame ()

RobotDynamics::Math::SpatialTransform	RobotDynamics::FixedReferenceFrame::getTransformToRoot () override
	Get this frames ReferenceFrame::transformToRoot. More...

RobotDynamics::Math::SpatialTransform	RobotDynamics::FixedReferenceFrame::getInverseTransformToRoot () override
	Get this frames ReferenceFrame::inverseTransformToRoot. More...

Variables
static ReferenceFramePtr	RobotDynamics::ReferenceFrame::worldFrame = ReferenceFrame::createAWorldFrame()

std::string	RobotDynamics::ReferenceFrame::frameName

ReferenceFramePtr	RobotDynamics::ReferenceFrame::parentFrame

RobotDynamics::Math::SpatialTransform	RobotDynamics::ReferenceFrame::transformFromParent

RobotDynamics::Math::SpatialTransform	RobotDynamics::ReferenceFrame::transformToRoot

RobotDynamics::Math::SpatialTransform	RobotDynamics::ReferenceFrame::inverseTransformToRoot

ReferenceFrame *	RobotDynamics::ReferenceFrame::rootFrame

bool	RobotDynamics::ReferenceFrame::isWorldFrame

bool	RobotDynamics::ReferenceFrame::isBodyFrame

unsigned int	RobotDynamics::ReferenceFrame::movableBodyId

Detailed Description

The ReferenceFrame object is the foundation of the way kinematics are handled. Each time a body is added via RobotDynamics::Model::addBody(), a pointer to a ReferenceFrame is created for that body and added to either RobotDynamics::Model::bodyFrames or RobotDynamics::Model::fixedBodyFrames depending on the type of body that is added. Additionally a reference frame is placed on the center of mass of each body and is stored in RobotDynamics::Model::bodyCenteredFrames.

These reference frames can then be used to explicitly express geometric entities(SpatialMotion, SpatialMomentum, SpatialForce, etc) in a reference frame. To query the name of a reference frame a geometric object is expressed in, you may call the ReferenceFrame::getName() method on the objects ReferenceFrame. Furthermore, to transform a framed geometric entity(anything that inheritcs from the RobotDynamics::FrameObject) into a different reference frame, you may simply call the RobotDynamics::FrameObject::changeFrame method and supply it a pointer to the frame you want the geometric object to be transformed to.

Note: If you create your own ReferenceFrame outside of those stored in the RobotDynamics::Model, you are required to call RobotDynamics::ReferenceFrame::update every time the created frames' ReferenceFrame::transformFromParent changes. The only exception to this is for RobotDynamics::FixedReferenceFrame objects. By definition, these frames are fixed and thus their ReferenceFrame::transformFromParent is set on construction and never changes, so after construction you do not need to call RobotDynamics::ReferenceFrame::update.

Typedef Documentation

◆ FixedReferenceFramePtr

typedef std::shared_ptr<FixedReferenceFrame> RobotDynamics::FixedReferenceFramePtr

◆ FixedReferenceFramePtrV

typedef std::vector<FixedReferenceFramePtr> RobotDynamics::FixedReferenceFramePtrV

◆ ReferenceFramePtr

typedef std::shared_ptr<ReferenceFrame> RobotDynamics::ReferenceFramePtr

◆ ReferenceFramePtrV

typedef std::vector<ReferenceFramePtr> RobotDynamics::ReferenceFramePtrV

Function Documentation

◆ calcCenterOfMass() [1/2]

void RobotDynamics::Utils::calcCenterOfMass	(	Model &	model,
		const Math::VectorNd &	q,
		const Math::VectorNd &	qdot,
		Math::FramePoint &	com,
		Math::FrameVector &	com_velocity,
		Math::FrameVector *	angular_momentum = `nullptr`,
		bool	update_kinematics = `true`
	)

Computes the Center of Mass (COM) and optionally its linear velocity and/or angular momentum.

When only interested in computing the location of the COM you can use nullptr as value for com_velocity/angular_momentum.

Parameters

model	The model for which we want to compute the COM
q	The current joint positions
qdot	The current joint velocities
com	location of the Center of Mass of the model in world frame
com_velocity	linear velocity of the COM in world frame
angular_momentum	(optional output) angular momentum of the model at the COM in a reference frame aligned with the world frame, but located at the center of mass
update_kinematics	(optional input) whether the kinematics should be updated (defaults to true)

◆ calcCenterOfMass() [2/2]

void RobotDynamics::Utils::calcCenterOfMass	(	Model &	model,
		const Math::VectorNd &	q,
		const Math::VectorNd &	qdot,
		Math::FramePoint &	com,
		Math::FrameVector *	com_velocity = `nullptr`,
		bool	update_kinematics = `true`
	)

Computes the Center of Mass (COM) and optionally its linear velocity.

When only interested in computing the location of the COM you can use nullptr as value for com_velocity.

Parameters

model	The model for which we want to compute the COM
q	The current joint positions
qdot	The current joint velocities
com	(output) location of the Center of Mass of the model in world frame
com_velocity	(optional output) linear velocity of the COM in world frame
update_kinematics	(optional input) whether the kinematics should be updated (defaults to true)

◆ checkReferenceFramesMatch() [1/2]

void RobotDynamics::ReferenceFrame::checkReferenceFramesMatch ( ReferenceFrame * referenceFrame ) const

◆ checkReferenceFramesMatch() [2/2]

void RobotDynamics::ReferenceFrame::checkReferenceFramesMatch ( ReferenceFramePtr referenceFrame ) const

Check if the argument ReferenceFrame equals this.

Parameters

referenceFrame

◆ createARootFrame()

static ReferenceFramePtr RobotDynamics::ReferenceFrame::createARootFrame ( const std::string & frameName )

inlinestatic

Creates a root frame with ReferenceFrame::parentFrame=nullptr.

Parameters

frameName

Returns: pointer to the created root frame

◆ createAWorldFrame()

static ReferenceFramePtr RobotDynamics::ReferenceFrame::createAWorldFrame ( const std::string & frameName = "world" )

inlinestaticprotected

Helper method to create a world frame.

Parameters

frameName

Returns: Pointer to the created world frame

◆ FixedReferenceFrame() [1/2]

RobotDynamics::FixedReferenceFrame::FixedReferenceFrame ( const FixedReferenceFrame & )

privatedelete

◆ FixedReferenceFrame() [2/2]

RobotDynamics::FixedReferenceFrame::FixedReferenceFrame	(	const std::string &	frameName,
		ReferenceFramePtr	parentFrame,
		const RobotDynamics::Math::SpatialTransform &	transformFromParent,
		unsigned int	movableBodyId
	)

inline

◆ getInverseTransformToRoot() [1/2]

virtual RobotDynamics::Math::SpatialTransform RobotDynamics::ReferenceFrame::getInverseTransformToRoot ( )

inlinevirtual

Get this frames ReferenceFrame::inverseTransformToRoot.

Returns: ReferenceFrame::inverseTransformToRoot

Reimplemented in RobotDynamics::FixedReferenceFrame.

◆ getInverseTransformToRoot() [2/2]

RobotDynamics::Math::SpatialTransform RobotDynamics::FixedReferenceFrame::getInverseTransformToRoot ( )

inlineoverridevirtual

Get this frames ReferenceFrame::inverseTransformToRoot.

Returns: ReferenceFrame::inverseTransformToRoot

Reimplemented from RobotDynamics::ReferenceFrame.

◆ getIsBodyFrame()

bool RobotDynamics::ReferenceFrame::getIsBodyFrame ( ) const

inline

Get boolean telling if this frame is a body frame or not. If it is a body frame, A pointer to this frame would be stored in Model::bodyFrames vector.

Returns: Boolean true if this frame is a body frame, false otherwise

◆ getIsWorldFrame()

bool RobotDynamics::ReferenceFrame::getIsWorldFrame ( ) const

inline

Get a boolean telling if this frame is the world frame.

Returns: Boolean true if this frame is world frame, false otherwise

◆ getMovableBodyId()

unsigned int RobotDynamics::ReferenceFrame::getMovableBodyId ( ) const

inline

Get the ID of the movable body this frame is attached to.

Returns: Unsigned int corresponding to the movable body this frame is attached to

◆ getName()

std::string RobotDynamics::ReferenceFrame::getName ( ) const

inline

Get the frame name.

Returns: ReferenceFrame::framenName

◆ getParentFrame()

ReferenceFramePtr RobotDynamics::ReferenceFrame::getParentFrame ( )

inline

get a pointer to this frames parent

Returns: ReferenceFrame::parentFrame

◆ getRootFrame()

ReferenceFrame* RobotDynamics::ReferenceFrame::getRootFrame ( )

inline

◆ getTransformFromParent()

RobotDynamics::Math::SpatialTransform RobotDynamics::ReferenceFrame::getTransformFromParent ( )

inline

Get spatial transform from parent to this frame.

Returns: SpatialTransform from parent to this frame

◆ getTransformToDesiredFrame() [1/2]

RobotDynamics::Math::SpatialTransform RobotDynamics::ReferenceFrame::getTransformToDesiredFrame ( ReferenceFramePtr desiredFrame )

virtual

Get the spatial transform from this frame to desiredFrame and store it in transformToPack.

Parameters

desiredFrame The resulting transform will transform vectors into desiredFrame

Returns: Spatial transform that will transform vectors into the ReferenceFrame desiredFrame

◆ getTransformToDesiredFrame() [2/2]

void RobotDynamics::ReferenceFrame::getTransformToDesiredFrame	(	RobotDynamics::Math::SpatialTransform &	transformToPack,
		ReferenceFramePtr	desiredFrame
	)

inline

Get the spatial transform from this frame to desiredFrame and store it in transformToPack.

Parameters

transformToPack	Resulting transform to the desired frame will be stored here
desiredFrame	The resulting transform will transform vectors into desiredFrame

◆ getTransformToParent()

RobotDynamics::Math::SpatialTransform RobotDynamics::ReferenceFrame::getTransformToParent ( )

inline

Get spatial transform this frame to its parent.

Returns: SpatialTransform from this frame to parent

◆ getTransformToRoot() [1/2]

virtual RobotDynamics::Math::SpatialTransform RobotDynamics::ReferenceFrame::getTransformToRoot ( )

inlinevirtual

Get this frames ReferenceFrame::transformToRoot.

Returns: ReferenceFrame::transformToRoot

Reimplemented in RobotDynamics::FixedReferenceFrame.

◆ getTransformToRoot() [2/2]

RobotDynamics::Math::SpatialTransform RobotDynamics::FixedReferenceFrame::getTransformToRoot ( )

inlineoverridevirtual

Get this frames ReferenceFrame::transformToRoot.

Returns: ReferenceFrame::transformToRoot

Reimplemented from RobotDynamics::ReferenceFrame.

◆ getWorldFrame()

static ReferenceFramePtr RobotDynamics::ReferenceFrame::getWorldFrame ( )

inlinestatic

Get a pointer to the world frame.

Returns: Pointer to world frame

◆ operator=() [1/2]

void RobotDynamics::FixedReferenceFrame::operator= ( const FixedReferenceFrame & )

privatedelete

◆ operator=() [2/2]

ReferenceFrame& RobotDynamics::ReferenceFrame::operator= ( const ReferenceFrame & other )

inline

◆ ReferenceFrame() [1/4]

RobotDynamics::ReferenceFrame::ReferenceFrame ( )

inline

Empty constructor. All contained ptrs will be initialize to nullptr.

◆ ReferenceFrame() [2/4]

RobotDynamics::ReferenceFrame::ReferenceFrame ( const ReferenceFrame & referenceFrameToCopy )

inline

Copy constructor.

Parameters

referenceFrameToCopy

◆ ReferenceFrame() [3/4]

RobotDynamics::ReferenceFrame::ReferenceFrame	(	const std::string &	frameName,
		bool	isWorldFrame,
		unsigned int	movableBodyId,
		bool	isBodyFrame
	)

inlineprotected

Constructor that creates a top level frame with parent=nullptr, and transforms to root being identity transform.

Parameters

frameName
isWorldFrame	True of creating the world frame, false if it's just a root frame
movableBodyId
isBodyFrame

◆ ReferenceFrame() [4/4]

RobotDynamics::ReferenceFrame::ReferenceFrame	(	const std::string &	frameName,
		ReferenceFramePtr	parentFrame,
		const RobotDynamics::Math::SpatialTransform &	transformFromParent,
		bool	isBodyFrame,
		unsigned int	movableBodyId
	)

inline

Constructor.

Parameters

frameName	Name of frame
parentFrame	Pointer to this frames parent ReferenceFrame
transformFromParent	Spatial transform from the parent frames perspective to this frame
isBodyFrame	Boolean true if this frame is a body frame(i.e. will be stored in Model::bodyFrames), false otherwise
movableBodyId	The ID of the movable body this frame is attached to. For frames attached to fixed bodies, this should be FixedBody::mMovableParent

◆ setTransformFromParent()

void RobotDynamics::ReferenceFrame::setTransformFromParent ( const RobotDynamics::Math::SpatialTransform & transformFromParent )

inline

Set a frames ReferenceFrame::transformToParent. For frames connected by a joint, this needs to be updated every tic BEFORE calling the ReferenceFrame::update method.

Parameters

transformFromParent The new ReferenceFrame::transformFromParent

◆ update()

void RobotDynamics::ReferenceFrame::update ( )

Recalculates this frames ReferenceFrame::transformToRoot and ReferenceFrame::inverseTransformToRoot which are used by FrameObject::changeFrame to change the ReferenceFrame FrameObjects are expressed in. If you create a ReferenceFrame you MUST call update every tic each time the frames ReferenceFrame::transformFromParent changes. Each time ReferenceFrame::setTransformFromParent changes, you need to call ReferenceFrame::transformFromParent before you call ReferenceFrame::update().

◆ updateCenterOfBuoyancyFrame() [1/6]

void RobotDynamics::HydroUtils::updateCenterOfBuoyancyFrame	(	Model &	model,
		const Math::Vector3d &	p_cob
	)

Updates the center of buoyancy frame of the robot be at location p_com and aligned with world frame.

Parameters

model	The model for which we want to compute the COB
p_com	The cob position in world frame

◆ updateCenterOfBuoyancyFrame() [2/6]

void RobotDynamics::HydroUtils::updateCenterOfBuoyancyFrame	(	Model &	model,
		const Math::Vector3d &	p_cob,
		const Math::Quaternion &	orientation
	)

Updates the center of buoyancy frame of the robot be at location p_com and aligned with world frame.

Parameters

model	The model for which we want to compute the COB
p_com	The cob position in world frame
orientation	Orientation of the com frame

◆ updateCenterOfBuoyancyFrame() [3/6]

void RobotDynamics::HydroUtils::updateCenterOfBuoyancyFrame	(	Model &	model,
		const Math::Vector3d &	p_cob,
		const Math::Vector3d &	euler_ypr
	)

Updates the center of buoyancy frame of the robot be at location p_com and to have orientation defined by the yaw/pitch/roll angles in euler_ypr argument. The euler_ypr argument is optional and if not provided the center of buoyancy reference frame will be aligned with world.

Parameters

model	The model for which we want to compute the COB
p_com	The cob position in world frame
euler_ypr	The desired orientation of the center of buoyancy frame

◆ updateCenterOfBuoyancyFrame() [4/6]

RobotDynamics::Math::FramePoint RobotDynamics::HydroUtils::updateCenterOfBuoyancyFrame	(	Model &	model,
		const Math::VectorNd &	q,
		bool	update_kinematics = `true`
	)

Computes the center of buoyancy and updates the center of buoyancy reference frame of the model.

Parameters

model	The model for which we want to compute the COB
q	The current joint positions
euler_ypr	The desired orientation of the center of buoyancy frame. Defaults to [0, 0, 0] in which case it would be aligned with world frame
update_kinematics	(optional input) whether the kinematics should be updated (defaults to true)

Returns: a frame point that represents the position of the origin of the center of buoyancy frame expressed in world frame

◆ updateCenterOfBuoyancyFrame() [5/6]

RobotDynamics::Math::FramePoint RobotDynamics::HydroUtils::updateCenterOfBuoyancyFrame	(	Model &	model,
		const Math::VectorNd &	q,
		const Math::Quaternion &	orientation,
		bool	update_kinematics = `true`
	)

Computes the center of buoyancy and updates the center of buoyancy reference frame of the model.

Parameters

model	The model for which we want to compute the COB
q	The current joint positions
orientation	The desired orientation of the center of buoyancy frame
update_kinematics	(optional input) whether the kinematics should be updated (defaults to true)

Returns: a frame point that represents the position of the origin of the center of buoyancy frame expressed in world frame

◆ updateCenterOfBuoyancyFrame() [6/6]

RobotDynamics::Math::FramePoint RobotDynamics::HydroUtils::updateCenterOfBuoyancyFrame	(	Model &	model,
		const Math::VectorNd &	q,
		const Math::Vector3d &	euler_ypr,
		bool	update_kinematics = `true`
	)

Computes the center of buoyancy and updates the center of buoyancy reference frame of the model.

Parameters

model	The model for which we want to compute the COB
q	The current joint positions
euler_ypr	The desired orientation of the center of buoyancy frame
update_kinematics	(optional input) whether the kinematics should be updated (defaults to true)

Returns: a frame point that represents the position of the origin of the center of buoyancy frame expressed in world frame

◆ updateCenterOfMassFrame() [1/6]

void RobotDynamics::Utils::updateCenterOfMassFrame	(	Model &	model,
		const Math::Vector3d &	p_com
	)

Updates the center of mass frame of the robot be at location p_com, aligned with world frame.

Parameters

model	The model for which we want to compute the COM
p_com	The com position in world frame

◆ updateCenterOfMassFrame() [2/6]

void RobotDynamics::Utils::updateCenterOfMassFrame	(	Model &	model,
		const Math::Vector3d &	p_com,
		const Math::Quaternion &	orientation
	)

Updates the center of mass frame of the robot be at location p_com and to have orientation defined by the orientation argument. The quaternion argument is optional and if not provided the center of mass reference frame will be aligned with world.

Parameters

model	The model for which we want to compute the COM
p_com	The com position in world frame
orientation	The desired orientation of the center of mass frame

◆ updateCenterOfMassFrame() [3/6]

void RobotDynamics::Utils::updateCenterOfMassFrame	(	Model &	model,
		const Math::Vector3d &	p_com,
		const Math::Vector3d &	euler_ypr
	)

Updates the center of mass frame of the robot be at location p_com and to have orientation defined by the yaw/pitch/roll angles in euler_ypr argument. The euler_ypr argument is optional and if not provided the center of mass reference frame will be aligned with world.

Parameters

model	The model for which we want to compute the COM
p_com	The com position in world frame
euler_ypr	The desired orientation of the center of mass frame

◆ updateCenterOfMassFrame() [4/6]

RobotDynamics::Math::FramePoint RobotDynamics::Utils::updateCenterOfMassFrame	(	Model &	model,
		const Math::VectorNd &	q,
		bool	update_kinematics = `true`
	)

Computes the center of mass and updates the center of mass reference frame of the model.

Parameters

model	The model for which we want to compute the COM
q	The current joint positions
update_kinematics	(optional input) whether the kinematics should be updated (defaults to true)

Returns: a frame point that represents the position of the origin of the center of mass frame expressed in world frame

◆ updateCenterOfMassFrame() [5/6]

RobotDynamics::Math::FramePoint RobotDynamics::Utils::updateCenterOfMassFrame	(	Model &	model,
		const Math::VectorNd &	q,
		const Math::Quaternion &	orientation,
		bool	update_kinematics = `true`
	)

Computes the center of mass and updates the center of mass reference frame of the model.

Parameters

model	The model for which we want to compute the COM
q	The current joint positions
orientation	The desired orientation of the center of mass frame
update_kinematics	(optional input) whether the kinematics should be updated (defaults to true)

Returns: a frame point that represents the position of the origin of the center of mass frame expressed in world frame

◆ updateCenterOfMassFrame() [6/6]

RobotDynamics::Math::FramePoint RobotDynamics::Utils::updateCenterOfMassFrame	(	Model &	model,
		const Math::VectorNd &	q,
		const Math::Vector3d &	euler_ypr,
		bool	update_kinematics = `true`
	)

Computes the center of mass and updates the center of mass reference frame of the model.

Parameters

model	The model for which we want to compute the COM
q	The current joint positions
euler_ypr	The desired orientation of the center of mass frame
update_kinematics	(optional input) whether the kinematics should be updated (defaults to true)

Returns: a frame point that represents the position of the origin of the center of mass frame expressed in world frame

◆ verifyFramesHaveSameRoot()

void RobotDynamics::ReferenceFrame::verifyFramesHaveSameRoot ( ReferenceFramePtr frame )

Check if two frames have the same roots.

Exceptions

ReferenceFrameException if the frames do not have the same roots

Parameters

frame

◆ ~FixedReferenceFrame()

virtual RobotDynamics::FixedReferenceFrame::~FixedReferenceFrame ( )

inlinevirtual

◆ ~ReferenceFrame()

virtual RobotDynamics::ReferenceFrame::~ReferenceFrame ( )

inlinevirtual

Destructor.

Variable Documentation

◆ frameName

std::string RobotDynamics::ReferenceFrame::frameName

protected

A frames name

◆ inverseTransformToRoot

RobotDynamics::Math::SpatialTransform RobotDynamics::ReferenceFrame::inverseTransformToRoot

protected

SpatialTransform to a frame from the root frame

◆ isBodyFrame

bool RobotDynamics::ReferenceFrame::isBodyFrame

protected

True if a frame is a body frame, false otherwise. Body frame pointers are stored in Model::bodyFrames

◆ isWorldFrame

bool RobotDynamics::ReferenceFrame::isWorldFrame

protected

True if a frame is the world frame, false otherwise

◆ movableBodyId

unsigned int RobotDynamics::ReferenceFrame::movableBodyId

protected

The body ID of the movable body a frame is attached to

◆ parentFrame

ReferenceFramePtr RobotDynamics::ReferenceFrame::parentFrame

protected

Pointer to a frames parent frames

◆ rootFrame

ReferenceFrame* RobotDynamics::ReferenceFrame::rootFrame

protected

◆ transformFromParent

RobotDynamics::Math::SpatialTransform RobotDynamics::ReferenceFrame::transformFromParent

protected

SpatialTransform to a frame from its parent

◆ transformToRoot

RobotDynamics::Math::SpatialTransform RobotDynamics::ReferenceFrame::transformToRoot

protected

SpatialTransform from a frame to the root frame

◆ worldFrame

ReferenceFramePtr RobotDynamics::ReferenceFrame::worldFrame = ReferenceFrame::createAWorldFrame()

staticprotected

Static world frame pointer

Classes

Typedefs

Functions

Variables

Detailed Description

Typedef Documentation

◆ FixedReferenceFramePtr

◆ FixedReferenceFramePtrV

◆ ReferenceFramePtr

◆ ReferenceFramePtrV

Function Documentation

◆ calcCenterOfMass() [1/2]

◆ calcCenterOfMass() [2/2]

◆ checkReferenceFramesMatch() [1/2]

◆ checkReferenceFramesMatch() [2/2]

◆ createARootFrame()

◆ createAWorldFrame()

◆ FixedReferenceFrame() [1/2]

◆ FixedReferenceFrame() [2/2]

◆ getInverseTransformToRoot() [1/2]

◆ getInverseTransformToRoot() [2/2]

◆ getIsBodyFrame()

◆ getIsWorldFrame()

◆ getMovableBodyId()

◆ getName()

◆ getParentFrame()

◆ getRootFrame()

◆ getTransformFromParent()

◆ getTransformToDesiredFrame() [1/2]

◆ getTransformToDesiredFrame() [2/2]

◆ getTransformToParent()

◆ getTransformToRoot() [1/2]

◆ getTransformToRoot() [2/2]

◆ getWorldFrame()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ ReferenceFrame() [1/4]

◆ ReferenceFrame() [2/4]

◆ ReferenceFrame() [3/4]

◆ ReferenceFrame() [4/4]

◆ setTransformFromParent()

◆ update()

◆ updateCenterOfBuoyancyFrame() [1/6]

◆ updateCenterOfBuoyancyFrame() [2/6]

◆ updateCenterOfBuoyancyFrame() [3/6]

◆ updateCenterOfBuoyancyFrame() [4/6]

◆ updateCenterOfBuoyancyFrame() [5/6]

◆ updateCenterOfBuoyancyFrame() [6/6]

◆ updateCenterOfMassFrame() [1/6]

◆ updateCenterOfMassFrame() [2/6]

◆ updateCenterOfMassFrame() [3/6]

◆ updateCenterOfMassFrame() [4/6]

◆ updateCenterOfMassFrame() [5/6]

◆ updateCenterOfMassFrame() [6/6]

◆ verifyFramesHaveSameRoot()

◆ ~FixedReferenceFrame()

◆ ~ReferenceFrame()

Variable Documentation

◆ frameName

◆ inverseTransformToRoot

◆ isBodyFrame

◆ isWorldFrame

◆ movableBodyId

◆ parentFrame

◆ rootFrame

◆ transformFromParent

◆ transformToRoot

◆ worldFrame