Description

template<class Real = double>
class chrono::ChFrameMoving< Real >

ChFrameMoving: a class for coordinate systems in 3D space.

A 'frame' coordinate system has a translation and a rotation respect to a 'parent' coordinate system, usually the absolute (world) coordinates.

Differently from a simple ChCoordsys() object, however, the ChFrame implements some optimizations because each ChFrame stores also a 3x3 rotation matrix, which can speed up coordinate transformations when a large amount of vectors must be transformed by the same coordinate frame.

Further info at the Coordinate transformations manual page.

#include <ChFrameMoving.h>

Inheritance diagram for chrono::ChFrameMoving< Real >:

[legend]

Collaboration diagram for chrono::ChFrameMoving< Real >:

[legend]

Public Member Functions
	ChFrameMoving (const ChVector< Real > &mv=ChVector< Real >(0, 0, 0), const ChQuaternion< Real > &mq=ChQuaternion< Real >(1, 0, 0, 0))
	Construct from pos and rot (as a quaternion)

	ChFrameMoving (const ChVector< Real > &mv, const ChMatrix33< Real > &ma)
	Construct from pos and rotation (as a 3x3 matrix)

	ChFrameMoving (const ChCoordsys< Real > &mc)
	Construct from a coordsys.

	ChFrameMoving (const ChFrame< Real > &mc)
	Construct from a frame.

	ChFrameMoving (const ChFrameMoving< Real > &other)
	Copy constructor, build from another moving frame.

virtual	~ChFrameMoving ()
	Destructor.

ChFrameMoving< Real > &	operator= (const ChFrameMoving< Real > &other)
	Assignment operator: copy from another moving frame.

ChFrameMoving< Real > &	operator= (const ChFrame< Real > &other)
	Assignment operator: copy from another frame.

bool	operator== (const ChFrameMoving< Real > &other) const
	Returns true for identical frames.

bool	operator!= (const ChFrameMoving< Real > &other) const
	Returns true for different frames.

ChFrameMoving< Real >	operator>> (const ChFrameMoving< Real > &Fb) const
	The '>>' operator transforms a coordinate system, so transformations can be represented with this syntax: new_frame = old_frame >> tr_frame; For a sequence of transformations, i.e. More...

ChFrameMoving< Real >	operator* (const ChFrameMoving< Real > &Fb) const
	The '' operator transforms a coordinate system, so transformations can be represented with this syntax: new_frame = tr_frame old_frame; For a sequence of transformations, i.e. More...

ChFrameMoving< Real > &	operator>>= (const ChFrameMoving< Real > &T)
	Performs pre-multiplication of this frame by another frame, for example: A>>=T means A'=T*A ; or A'=A >> T.

ChFrameMoving< Real > &	operator%= (const ChFrameMoving< Real > &T)
	Performs pre-multiplication of this frame by another frame, for example: A%=T means A'=T*A ; or A'=A >> T Note: DEPRECATED, use >>= instead.

ChFrameMoving< Real > &	operator*= (const ChFrameMoving< Real > &T)
	Performs post-multiplication of this frame by another frame, for example: A=T means A'=AT ; or A'=T >> A.

ChFrameMoving< Real > &	operator>>= (const ChVector< Real > &D)
	Performs pre-multiplication of this frame by a vector D, to 'move' by a displacement D:

ChFrameMoving< Real > &	operator>>= (const ChQuaternion< Real > &R)
	Performs pre-multiplication of this frame by a quaternion R, to 'rotate' it by R:

ChFrameMoving< Real > &	operator>>= (const ChCoordsys< Real > &F)
	Performs pre-multiplication of this frame by a ChCoordsys F:

ChFrameMoving< Real > &	operator>>= (const ChFrame< Real > &F)
	Performs pre-multiplication of this frame by a ChFrame F:

ChCoordsys< Real > &	GetCoord_dt ()
	Return both current rotation and translation speeds as a coordsystem object, with vector and quaternion.

const ChCoordsys< Real > &	GetCoord_dt () const

ChCoordsys< Real > &	GetCoord_dtdt ()
	Return both current rotation and translation accelerations as a coordsystem object, with vector and quaternion.

const ChCoordsys< Real > &	GetCoord_dtdt () const

ChVector< Real > &	GetPos_dt ()
	Return the current speed as a 3d vector.

const ChVector< Real > &	GetPos_dt () const

ChVector< Real > &	GetPos_dtdt ()
	Return the current acceleration as a 3d vector.

const ChVector< Real > &	GetPos_dtdt () const

ChQuaternion< Real > &	GetRot_dt ()
	Return the current rotation speed as a quaternion.

const ChQuaternion< Real > &	GetRot_dt () const

ChQuaternion< Real > &	GetRot_dtdt ()
	Return the current rotation acceleration as a quaternion.

const ChQuaternion< Real > &	GetRot_dtdt () const

ChVector< Real >	GetWvel_loc () const
	Computes the actual angular speed (expressed in local coords)

ChVector< Real >	GetWvel_par () const
	Computes the actual angular speed (expressed in parent coords)

ChVector< Real >	GetWacc_loc () const
	Computes the actual angular acceleration (expressed in local coords)

ChVector< Real >	GetWacc_par () const
	Computes the actual angular acceleration (expressed in parent coords)

virtual void	SetCoord_dt (const ChCoordsys< Real > &mcoord_dt)
	Set both linear speed and rotation speed as a single ChCoordsys derivative.

virtual void	SetPos_dt (const ChVector< Real > &mvel)
	Set the linear speed.

virtual void	SetRot_dt (const ChQuaternion< Real > &mrot_dt)
	Set the rotation speed as a quaternion. More...

virtual void	SetWvel_loc (const ChVector< Real > &wl)
	Set the rotation speed from given angular speed (expressed in local csys)

virtual void	SetWvel_par (const ChVector< Real > &wp)
	Set the rotation speed from given angular speed (expressed in parent csys)

virtual void	SetCoord_dtdt (const ChCoordsys< Real > &mcoord_dtdt)
	Set both linear acceleration and rotation acceleration as a single ChCoordsys derivative.

virtual void	SetPos_dtdt (const ChVector< Real > &macc)
	Set the linear acceleration.

virtual void	SetRot_dtdt (const ChQuaternion< Real > &mrot_dtdt)
	Set the rotation acceleration as a quaternion derivative. More...

virtual void	SetWacc_loc (const ChVector< Real > &al)
	Set the rotation acceleration from given angular acceleration (expressed in local csys) Note: even when the local angular acceleration is zero, you are still encouraged to call this method bacause q_dtdt might be nonzero due to nonzero q_dt in case of rotational motion.

virtual void	SetWacc_par (const ChVector< Real > &ap)
	Set the rotation speed from given angular speed (expressed in parent csys)

void	Compute_Adt (ChMatrix33< Real > &mA_dt) const
	Computes the time derivative of rotation matrix, mAdt.

void	Compute_Adtdt (ChMatrix33< Real > &mA_dtdt)
	Computes the 2nd time derivative of rotation matrix, mAdtdt.

ChMatrix33< Real >	GetA_dt ()
	Computes and returns an Adt matrix (-note: prefer using Compute_Adt() directly for better performance)

ChMatrix33< Real >	GetA_dtdt ()
	Computes and returns an Adt matrix (-note: prefer using Compute_Adtdt() directly for better performance)

void	ConcatenatePreTransformation (const ChFrameMoving< Real > &T)
	Apply a transformation (rotation and translation) represented by another ChFrameMoving T. More...

void	ConcatenatePostTransformation (const ChFrameMoving< Real > &T)
	Apply a transformation (rotation and translation) represented by another ChFrameMoving T in local coordinate. More...

ChVector< Real >	PointSpeedLocalToParent (const ChVector< Real > &localpos) const
	Given the position of a point in local frame coords, and assuming it is sticky to frame, return the speed in parent coords.

ChVector< Real >	PointSpeedLocalToParent (const ChVector< Real > &localpos, const ChVector< Real > &localspeed) const
	Given the position localpos of a point in the local reference frame, assuming that the point moves in the local reference frame with localspeed, return the speed in the parent reference frame.

ChVector< Real >	PointAccelerationLocalToParent (const ChVector< Real > &localpos) const
	Given the position of a point in local frame coords, and assuming it is sticky to frame, return the acceleration in parent coords. More...

ChVector< Real >	PointAccelerationLocalToParent (const ChVector< Real > &localpos, const ChVector< Real > &localspeed, const ChVector< Real > &localacc) const
	Given the position of a point in local frame coords, and assuming it has a frame-relative speed localspeed and frame-relative acceleration localacc, return the acceleration in parent coords.

ChVector< Real >	PointSpeedParentToLocal (const ChVector< Real > &parentpos, const ChVector< Real > &parentspeed) const
	Given the position of a point in parent frame coords, and assuming it has an absolute speed parentspeed, return the speed in local coords.

ChVector< Real >	PointAccelerationParentToLocal (const ChVector< Real > &parentpos, const ChVector< Real > &parentspeed, const ChVector< Real > &parentacc) const
	Given the position of a point in parent frame coords, and assuming it has an absolute speed parentspeed and absolute acceleration parentacc, return the acceleration in local coords.

void	TransformLocalToParent (const ChFrameMoving< Real > &local, ChFrameMoving< Real > &parent) const
	This function transforms a frame from 'this' local coordinate system to parent frame coordinate system, and also transforms the speed and acceleration of the frame. More...

void	TransformParentToLocal (const ChFrameMoving< Real > &parent, ChFrameMoving< Real > &local) const
	This function transforms a frame from the parent coordinate system to 'this' local frame coordinate system. More...

bool	Equals (const ChFrameMoving< Real > &other) const
	Returns true if coordsys is identical to other coordsys.

bool	Equals (const ChFrameMoving< Real > &other, Real tol) const
	Returns true if coordsys is equal to other coordsys, within a tolerance 'tol'.

virtual void	Invert () override
	The transformation (also for speeds, accelerations) is inverted in place. More...

ChFrameMoving< Real >	GetInverse () const

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::ChFrame< Real >
	ChFrame (const ChVector< Real > &mv=ChVector< Real >(0, 0, 0), const ChQuaternion< Real > &mq=ChQuaternion< Real >(1, 0, 0, 0))
	Default constructor, or construct from pos and rot (as a quaternion)

	ChFrame (const ChVector< Real > &mv, const ChMatrix33< Real > &ma)
	Construct from pos and rotation (as a 3x3 matrix)

	ChFrame (const ChCoordsys< Real > &mc)
	Construct from a coordsys.

	ChFrame (const ChVector< Real > &mv, const Real alpha, const ChVector< Real > &mu)
	Construct from position mv and rotation of angle alpha around unit vector mu.

	ChFrame (const ChFrame< Real > &other)
	Copy constructor, build from another frame.

ChFrame< Real > &	operator= (const ChFrame< Real > &other)
	Assignment operator: copy from another frame.

bool	operator== (const ChFrame< Real > &other) const
	Returns true for identical frames.

bool	operator!= (const ChFrame< Real > &other) const
	Returns true for different frames.

ChFrame< Real >	operator>> (const ChFrame< Real > &Fb) const
	The '>>' operator transforms a coordinate system, so transformations can be represented with this syntax: new_frame = old_frame >> tr_frame; For a sequence of transformations, i.e. More...

ChFrame< Real >	operator* (const ChFrame< Real > &Fb) const
	The '>>' operator transforms a vector, so transformations can be represented with this syntax: new_v = old_v >> tr_frame; For a sequence of transformations, i.e. More...

ChVector< Real >	operator* (const ChVector< Real > &V) const
	The '' operator transforms a vector, so transformations can be represented with this syntax: new_v = tr_frame old_v; For a sequence of transformations, i.e. More...

ChVector< Real >	operator/ (const ChVector< Real > &V) const
	The '/' is like the '*' operator (see), but uses the inverse transformation for A, in A/b. More...

ChFrame< Real > &	operator>>= (const ChFrame< Real > &T)
	Performs pre-multiplication of this frame by another frame, for example: A>>=T means A'=T*A ; or A'=A >> T.

ChFrame< Real > &	operator%= (const ChFrame< Real > &T)
	Performs pre-multiplication of this frame by another frame, for example: A%=T means A'=T*A ; or A'=A >> T Note: DEPRECATED, use >>= instead.

ChFrame< Real > &	operator*= (const ChFrame< Real > &T)
	Performs post-multiplication of this frame by another frame, for example: A=T means A'=AT ; or A'=T >> A.

ChFrame< Real > &	operator>>= (const ChVector< Real > &D)
	Performs pre-multiplication of this frame by a vector D, to 'move' by a displacement D:

ChFrame< Real > &	operator>>= (const ChQuaternion< Real > &R)
	Performs pre-multiplication of this frame by a quaternion R, to 'rotate' it by R:

ChFrame< Real > &	operator>>= (const ChCoordsys< Real > &F)
	Performs pre-multiplication of this frame by a ChCoordsys F, to transform it:

ChCoordsys< Real > &	GetCoord ()
	Return both current rotation and translation as a coordsystem object, with vector and quaternion.

const ChCoordsys< Real > &	GetCoord () const

ChVector< Real > &	GetPos ()
	Return the current translation as a 3d vector.

const ChVector< Real > &	GetPos () const

ChQuaternion< Real > &	GetRot ()
	Return the current rotation as a quaternion.

const ChQuaternion< Real > &	GetRot () const

ChMatrix33< Real > &	GetA ()
	Return the current rotation as a 3x3 matrix.

const ChMatrix33< Real > &	GetA () const

ChVector< Real >	GetRotAxis ()
	Get axis of finite rotation, in parent space.

Real	GetRotAngle ()
	Get angle of rotation about axis of finite rotation.

void	SetCoord (const ChCoordsys< Real > &mcoord)
	Impose both translation and rotation as a single ChCoordsys. More...

void	SetCoord (const ChVector< Real > &mv, const ChQuaternion< Real > &mq)
	Impose both translation and rotation. More...

void	SetRot (const ChQuaternion< Real > &mrot)
	Impose the rotation as a quaternion. More...

void	SetRot (const ChMatrix33< Real > &mA)
	Impose the rotation as a 3x3 matrix. More...

void	SetPos (const ChVector< Real > &mpos)
	Impose the translation.

void	ConcatenatePreTransformation (const ChFrame< Real > &T)
	Apply a transformation (rotation and translation) represented by another ChFrame T. More...

void	ConcatenatePostTransformation (const ChFrame< Real > &T)
	Apply a transformation (rotation and translation) represented by another ChFrame T in local coordinate. More...

void	Move (const ChVector< Real > &V)
	An easy way to move the frame by the amount specified by vector V, (assuming V expressed in parent coordinates)

void	Move (const ChCoordsys< Real > &VR)
	Apply both translation and rotation, assuming both expressed in parent coordinates, as a vector for translation and quaternion for rotation,.

ChVector< Real >	TransformLocalToParent (const ChVector< Real > &local) const
	This function transforms a point from the local frame coordinate system to the parent coordinate system. More...

ChVector< Real >	TransformPointLocalToParent (const ChVector< Real > &local) const

ChVector< Real >	TransformParentToLocal (const ChVector< Real > &parent) const
	This function transforms a point from the parent coordinate system to local frame coordinate system. More...

ChVector< Real >	TransformPointParentToLocal (const ChVector< Real > &parent) const

void	TransformLocalToParent (const ChFrame< Real > &local, ChFrame< Real > &parent) const
	This function transforms a frame from 'this' local coordinate system to parent frame coordinate system. More...

void	TransformParentToLocal (const ChFrame< Real > &parent, ChFrame< Real > &local) const
	This function transforms a frame from the parent coordinate system to 'this' local frame coordinate system. More...

ChVector< Real >	TransformDirectionParentToLocal (const ChVector< Real > &mdirection) const
	This function transforms a direction from 'this' local coordinate system to parent frame coordinate system. More...

ChVector< Real >	TransformDirectionLocalToParent (const ChVector< Real > &mdirection) const
	This function transforms a direction from the parent frame coordinate system to 'this' local coordinate system. More...

bool	Equals (const ChFrame< Real > &other) const
	Returns true if coordsys is identical to other coordsys.

bool	Equals (const ChFrame< Real > &other, Real tol) const
	Returns true if coordsys is equal to other coordsys, within a tolerance 'tol'.

void	Normalize ()
	Normalize the rotation, so that quaternion has unit length.

virtual void	SetIdentity ()
	Sets to no translation and no rotation.

ChFrame< Real >	GetInverse () const

Public Attributes
ChCoordsys< Real >	coord_dt
	Rotation and position speed, as vector+quaternion.

ChCoordsys< Real >	coord_dtdt
	Rotation and position acceleration, as vector+quaternion.

Public Attributes inherited from chrono::ChFrame< Real >
ChCoordsys< Real >	coord
	Rotation and position, as vector+quaternion.

ChMatrix33< Real >	Amatrix
	3x3 orthogonal rotation matrix

Member Function Documentation

◆ ConcatenatePostTransformation()

template<class Real = double>

void chrono::ChFrameMoving< Real >::ConcatenatePostTransformation ( const ChFrameMoving< Real > & T )

inline

Apply a transformation (rotation and translation) represented by another ChFrameMoving T in local coordinate.

This is equivalent to post-multiply this frame by the other frame T: this'= this * T; or this' = T >> this

◆ ConcatenatePreTransformation()

template<class Real = double>

void chrono::ChFrameMoving< Real >::ConcatenatePreTransformation ( const ChFrameMoving< Real > & T )

inline

Apply a transformation (rotation and translation) represented by another ChFrameMoving T.

This is equivalent to pre-multiply this frame by the other frame T: this'= T * this; or this' = this >> T

◆ Invert()

template<class Real = double>

virtual void chrono::ChFrameMoving< Real >::Invert ( )

inlineoverridevirtual

The transformation (also for speeds, accelerations) is inverted in place.

That is if w=A*v, then A.Invert();v=A*w;

Reimplemented from chrono::ChFrame< Real >.

◆ operator*()

template<class Real = double>

ChFrameMoving<Real> chrono::ChFrameMoving< Real >::operator* ( const ChFrameMoving< Real > & Fb ) const

inline

The '*' operator transforms a coordinate system, so transformations can be represented with this syntax: new_frame = tr_frame * old_frame; For a sequence of transformations, i.e.

a chain of coordinate systems, you can also write this (just like you would do with a sequence of Denavitt-Hartemberg matrix multiplications!) new_frame = frame1to0 * frame2to1 * frame3to2 * old_frame; This operation is not commutative. Also speeds and accelerations are transformed.

◆ operator>>()

template<class Real = double>

ChFrameMoving<Real> chrono::ChFrameMoving< Real >::operator>> ( const ChFrameMoving< Real > & Fb ) const

inline

The '>>' operator transforms a coordinate system, so transformations can be represented with this syntax: new_frame = old_frame >> tr_frame; For a sequence of transformations, i.e.

a chain of coordinate systems, you can also write this (like you would do with a sequence of Denavitt-Hartemberg matrix multiplications, but in the opposite order...) new_frame = old_frame >> frame3to2 >> frame2to1 >> frame1to0; This operation is not commutative. Also speeds and accelerations are transformed.

◆ PointAccelerationLocalToParent()

template<class Real = double>

ChVector<Real> chrono::ChFrameMoving< Real >::PointAccelerationLocalToParent ( const ChVector< Real > & localpos ) const

inline

Given the position of a point in local frame coords, and assuming it is sticky to frame, return the acceleration in parent coords.

Note: please ensure all the first and second derivatives of pos and rot are assigned as the precondition. A special occasion: when the local angular acceleration is zero, it's still necessary to call SetWacc_loc(VNULL) bacause the q_dtdt may be nonzero due to nonzero q_dt in case of rotational motion.

◆ SetRot_dt()

template<class Real = double>

virtual void chrono::ChFrameMoving< Real >::SetRot_dt ( const ChQuaternion< Real > & mrot_dt )

inlinevirtual

Set the rotation speed as a quaternion.

Note: the quaternion must already satisfy dot(q,q_dt)=0

◆ SetRot_dtdt()

template<class Real = double>

virtual void chrono::ChFrameMoving< Real >::SetRot_dtdt ( const ChQuaternion< Real > & mrot_dtdt )

inlinevirtual

Set the rotation acceleration as a quaternion derivative.

Note: the quaternion must already satisfy dot(q,q_dt)=0

◆ TransformLocalToParent()

template<class Real = double>

void chrono::ChFrameMoving< Real >::TransformLocalToParent	(	const ChFrameMoving< Real > &	local,
		ChFrameMoving< Real > &	parent
	)		const

inline

This function transforms a frame from 'this' local coordinate system to parent frame coordinate system, and also transforms the speed and acceleration of the frame.

Parameters

local	frame to transform, given in local frame coordinates
parent	transformed frame, in parent coordinates, will be stored here

◆ TransformParentToLocal()

template<class Real = double>

void chrono::ChFrameMoving< Real >::TransformParentToLocal	(	const ChFrameMoving< Real > &	parent,
		ChFrameMoving< Real > &	local
	)		const

inline

This function transforms a frame from the parent coordinate system to 'this' local frame coordinate system.

Parameters

parent	frame to transform, given in parent coordinates
local	transformed frame, in local coordinates, will be stored here

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

/builds/uwsbel/chrono/src/chrono/core/ChFrameMoving.h

Description

template<class Real = double> class chrono::ChFrameMoving< Real >

Public Member Functions

Public Attributes

Member Function Documentation

◆ ConcatenatePostTransformation()

◆ ConcatenatePreTransformation()

◆ Invert()

◆ operator*()

◆ operator>>()

◆ PointAccelerationLocalToParent()

◆ SetRot_dt()

◆ SetRot_dtdt()

◆ TransformLocalToParent()

◆ TransformParentToLocal()

template<class Real = double>
class chrono::ChFrameMoving< Real >