Converts Euler angles and derivatives to angular quantities. More...

#include <euler_converter.h>

Public Member Functions
Jacobian	DerivOfRotVecMult (double t, const Vector3d &v, bool inverse) const
	Returns the derivative of result of the linear equation M*v.
	EulerConverter ()
	EulerConverter (const NodeSpline::Ptr &euler_angles)
	Constructs and links this object to the Euler angle values.
Vector3d	GetAngularAccelerationInWorld (double t) const
	Converts Euler angles, rates and rate derivatives o angular accelerations.
Vector3d	GetAngularVelocityInWorld (double t) const
	Converts Euler angles and Euler rates to angular velocities.
Jacobian	GetDerivOfAngAccWrtEulerNodes (double t) const
	Jacobian of the angular acceleration with respect to the Euler nodes.
Jacobian	GetDerivOfAngVelWrtEulerNodes (double t) const
	Jacobian of the angular velocity with respect to the Euler nodes.
Eigen::Quaterniond	GetQuaternionBaseToWorld (double t) const
	Converts the Euler angles at time t to a Quaternion.
MatrixSXd	GetRotationMatrixBaseToWorld (double t) const
	Converts the Euler angles at time t to a rotation matrix.
virtual	~EulerConverter ()
Private Member Functions
JacRowMatrix	GetDerivativeOfRotationMatrixWrtNodes (double t) const
	matrix of derivatives of each cell w.r.t node values.
Jacobian	GetDerivMdotwrtNodes (double t, Dim3D dim) const
	Derivative of the dim row of the time derivative of M with respect to the node values.
Jacobian	GetDerivMwrtNodes (double t, Dim3D dim) const
	Derivative of the dim row of matrix M with respect to the node values.
JacobianRow	GetJac (double t, Dx deriv, Dim3D dim) const
Static Private Member Functions
static Vector3d	GetAngularAccelerationInWorld (State euler)
static Vector3d	GetAngularVelocityInWorld (const EulerAngles &pos, const EulerRates &vel)
static MatrixSXd	GetM (const EulerAngles &xyz)
	Matrix that maps euler rates to angular velocities in world.
static MatrixSXd	GetMdot (const EulerAngles &xyz, const EulerRates &xyz_d)
	time derivative of GetM()
static Eigen::Quaterniond	GetQuaternionBaseToWorld (const EulerAngles &pos)
static MatrixSXd	GetRotationMatrixBaseToWorld (const EulerAngles &xyz)
Private Attributes
NodeSpline::Ptr	euler_
Jacobian	jac_wrt_nodes_structure_

Detailed Description

Converts Euler angles and derivatives to angular quantities.

Euler angles, their first derivatives (Euler rates) and their second derivatives fully define the angular state of an rigid body in space. This class provides equivalent formulation of these values, specifically:

Orientation as Rotation matrix or Quaternion.
Angular velocity (x,y,z)
Angular acceleration (x,y,z)

Furthermore, the Euler angle spline is fully defined by a set of node values. This class also gives the derivative of the above quantities with respect to the values of these nodes.

Formulas taken from kindr: http://docs.leggedrobotics.com/kindr/cheatsheet_latest.pdf

See matlab script "matlab/euler_converter.m" for derivation.

Definition at line 62 of file euler_converter.h.

Constructor & Destructor Documentation

towr::EulerConverter::EulerConverter ( )

towr::EulerConverter::EulerConverter ( const NodeSpline::Ptr & euler_angles )

Constructs and links this object to the Euler angle values.

Parameters:

euler_angles_spline The Euler angle spline defined by node values.

The order of application that is assumed here is (Z,Y',X''). So in order to get the orientation of an object in space from the Euler angles, we first rotate around yaw(z) axis, then around new pitch(y) axis and finally around new roll(x) axis.

However, the 3-dimensional Euler angles must store the euler angles, rates, and rate derivatives in the order (roll, pitch, yaw): double roll = euler_angles->GetPoint(t).x(); double pitch = euler_angles->GetPoint(t).y(); double yaw = euler_angles->GetPoint(t).z();

Definition at line 38 of file euler_converter.cc.

virtual towr::EulerConverter::~EulerConverter ( ) [virtual]

Member Function Documentation

EulerConverter::Jacobian towr::EulerConverter::DerivOfRotVecMult	(	double	t,
		const Vector3d &	v,
		bool	inverse
	)		const

Returns the derivative of result of the linear equation M*v.

M is the rotation matrix from base to world, defined by the Euler nodes. v is any vector independent of the Euler nodes. The sensitivity of the 3-dimensional vector w.r.t the Euler node values is given.

Parameters:

t	time at which the Euler angles are evaluated.
v	vector (e.g. relative position, velocity, acceleration).
inverse	if true, the derivative for M^(-1)*v is evaluated.

Returns:: 3 x n dimensional matrix (n = number of Euler node values).

Definition at line 225 of file euler_converter.cc.

Eigen::Vector3d towr::EulerConverter::GetAngularAccelerationInWorld ( double t ) const

Converts Euler angles, rates and rate derivatives o angular accelerations.

Parameters:

t	The current time in the euler angles spline.

Returns:: A 3-dim vector (x,y,z) of the angular accelerations in world frame.

Definition at line 73 of file euler_converter.cc.

Eigen::Vector3d towr::EulerConverter::GetAngularAccelerationInWorld ( State euler ) [static, private]

See also:: GetAngularAccelerationInWorld(t)

Definition at line 80 of file euler_converter.cc.

Eigen::Vector3d towr::EulerConverter::GetAngularVelocityInWorld ( double t ) const

Converts Euler angles and Euler rates to angular velocities.

Parameters:

t	The current time in the euler angles spline.

Returns:: A 3-dim vector (x,y,z) of the angular velocities in world frame.

Definition at line 59 of file euler_converter.cc.

Eigen::Vector3d towr::EulerConverter::GetAngularVelocityInWorld	(	const EulerAngles &	pos,
		const EulerRates &	vel
	)		`[static, private]`

See also:: GetAngularVelocityInWorld(t)

Definition at line 66 of file euler_converter.cc.

EulerConverter::JacRowMatrix towr::EulerConverter::GetDerivativeOfRotationMatrixWrtNodes ( double t ) const [private]

matrix of derivatives of each cell w.r.t node values.

This 2d-array has the same dimensions as the rotation matrix M_IB, but each cell if filled with a row vector.

Definition at line 244 of file euler_converter.cc.

EulerConverter::Jacobian towr::EulerConverter::GetDerivMdotwrtNodes	(	double	t,
		Dim3D	dim
	)		const `[private]`

Derivative of the dim row of the time derivative of M with respect to the node values.

Parameters:

dim	Which dimension of the angular acceleration is desired.

Definition at line 273 of file euler_converter.cc.

EulerConverter::Jacobian towr::EulerConverter::GetDerivMwrtNodes	(	double	t,
		Dim3D	dim
	)		const `[private]`

Derivative of the dim row of matrix M with respect to the node values.

Parameters:

dim	Which dimension of the angular acceleration is desired.

Returns:: the Jacobian w.r.t the coefficients for each of the 3 rows of the matrix stacked on top of each other.

Definition at line 170 of file euler_converter.cc.

EulerConverter::Jacobian towr::EulerConverter::GetDerivOfAngAccWrtEulerNodes ( double t ) const

Jacobian of the angular acceleration with respect to the Euler nodes.

Parameters:

t	The current time in the Euler angles spline.

Returns:: The 3xn Jacobian Matrix of derivatives. 3: because angular acceleration has an x,y,z component n: the number of optimized nodes values defining the Euler spline.

Definition at line 105 of file euler_converter.cc.

EulerConverter::Jacobian towr::EulerConverter::GetDerivOfAngVelWrtEulerNodes ( double t ) const

Jacobian of the angular velocity with respect to the Euler nodes.

Parameters:

t	The current time in the Euler angles spline.

Returns:: The 3xn Jacobian Matrix of derivatives. 3: because angular velocity has an x,y,z component. n: the number of optimized nodes values defining the Euler spline.

Definition at line 86 of file euler_converter.cc.

EulerConverter::JacobianRow towr::EulerConverter::GetJac	(	double	t,
		Dx	deriv,
		Dim3D	dim
	)		const `[private]`

Definition at line 309 of file euler_converter.cc.

EulerConverter::MatrixSXd towr::EulerConverter::GetM ( const EulerAngles & xyz ) [static, private]

Matrix that maps euler rates to angular velocities in world.

Make sure euler rates are ordered roll-pitch-yaw. They are however applied in the order yaw-pitch-role to determine the angular velocities.

Definition at line 135 of file euler_converter.cc.

EulerConverter::MatrixSXd towr::EulerConverter::GetMdot	(	const EulerAngles &	xyz,
		const EulerRates &	xyz_d
	)		`[static, private]`

time derivative of GetM()

Definition at line 152 of file euler_converter.cc.

Eigen::Quaterniond towr::EulerConverter::GetQuaternionBaseToWorld ( double t ) const

Converts the Euler angles at time t to a Quaternion.

Parameters:

t	The current time in the euler angles spline.

Returns:: A Quaternion the maps a vector from base to world frame.

Definition at line 45 of file euler_converter.cc.

Eigen::Quaterniond towr::EulerConverter::GetQuaternionBaseToWorld ( const EulerAngles & pos ) [static, private]

See also:: GetQuaternionBaseToWorld(t)

Definition at line 52 of file euler_converter.cc.

EulerConverter::MatrixSXd towr::EulerConverter::GetRotationMatrixBaseToWorld ( double t ) const

Converts the Euler angles at time t to a rotation matrix.

Parameters:

t	The current time in the euler angles spline.

Returns:: A 3x3 rotation matrix that maps a vector from base to world frame.

Definition at line 202 of file euler_converter.cc.

EulerConverter::MatrixSXd towr::EulerConverter::GetRotationMatrixBaseToWorld ( const EulerAngles & xyz ) [static, private]

See also:: GetRotationMatrixBaseToWorld(t)

Definition at line 209 of file euler_converter.cc.

Member Data Documentation

NodeSpline::Ptr towr::EulerConverter::euler_ [private]

Definition at line 152 of file euler_converter.h.

Jacobian towr::EulerConverter::jac_wrt_nodes_structure_ [private]

Definition at line 208 of file euler_converter.h.

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

Public Member Functions

Private Member Functions

Static Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation