scmp::estimation::Madgwick< T > Class Template Reference

Madgwick implements an efficient Orientation estimation for Intertial Measurement Units (IMUs). More...

#include <Madgwick.h>

Public Member Functions
	Madgwick ()
	The Madgwick estimation is initialised with an identity MakeQuaternion.
	Madgwick (scmp::geom::Vector< T, 3 > sf)
	The Madgwick estimation is initialised with a sensor frame.
	Madgwick (scmp::geom::Quaternion< T > sf)
	Initialise the estimation with a sensor frame MakeQuaternion.
scmp::geom::Quaternion< T >	Orientation () const
	Return the current orientation as measured by the estimation.
scmp::geom::Quaternion< T >	AngularRate (const scmp::geom::Vector< T, 3 > &gyro) const
	Return the estimation's rate of angular change from a sensor frame.
void	UpdateFrame (const scmp::geom::Quaternion< T > &sf, T delta)
	Update the sensor frame to a new frame.
void	UpdateFrame (const scmp::geom::Quaternion< T > &sf)
	Update the sensor frame to a new frame.
void	UpdateAngularOrientation (const scmp::geom::Vector< T, 3 > &gyro, T delta)
	Update the sensor frame with a gyroscope reading.
void	UpdateAngularOrientation (const scmp::geom::Vector< T, 3 > &gyro)
	Update the sensor frame with a gyroscope reading.
scmp::geom::Vector< T, 3 >	Euler ()
	Retrieve a vector of the Euler angles in ZYX Orientation.
void	DeltaT (T newDeltaT)
	Set the default Δt.
T	DeltaT ()
	Retrieve the estimation's current ΔT.

Detailed Description

template<typename T>
class scmp::estimation::Madgwick< T >

Madgwick implements an efficient Orientation estimation for Intertial Measurement Units (IMUs).

Madgwick is a novel Orientation estimation applicable to IMUs consisting of tri-Axis gyroscopes and accelerometers, and MARG sensor arrays that also include tri-Axis magnetometers. The MARG implementation incorporates magnetic distortionand gyroscope bias drift compensation.

It is described in the paper An efficient Orientation estimation for inertial and inertial/magnetic sensor arrays.

Template Parameters

T	A floating point type.

Constructor & Destructor Documentation

Madgwick() [1/3]

template<typename T >

scmp::estimation::Madgwick< T >::Madgwick ( )

inline

The Madgwick estimation is initialised with an identity MakeQuaternion.

Madgwick() [2/3]

template<typename T >

scmp::estimation::Madgwick< T >::Madgwick ( scmp::geom::Vector< T, 3 >  sf )

inline

The Madgwick estimation is initialised with a sensor frame.

Parameters

sf	A sensor frame; if zero, the sensor frame will be initialised as an identity MakeQuaternion.

Madgwick() [3/3]

template<typename T >

scmp::estimation::Madgwick< T >::Madgwick ( scmp::geom::Quaternion< T >  sf )

inline

Initialise the estimation with a sensor frame MakeQuaternion.

Parameters

sf	A MakeQuaternion representing the current Orientation.

Member Function Documentation

AngularRate()

template<typename T >

scmp::geom::Quaternion< T > scmp::estimation::Madgwick< T >::AngularRate ( const scmp::geom::Vector< T, 3 > &  gyro ) const

inline

Return the estimation's rate of angular change from a sensor frame.

Return the rate of change of the Orientation of the earth frame with respect to the sensor frame.

Parameters

gyro	A three-dimensional vector containing gyro readings as w_x, w_y, w_z.

Returns

A MakeQuaternion representing the rate of angular change.

DeltaT() [1/2]

template<typename T >

T scmp::estimation::Madgwick< T >::DeltaT ( )

inline

Retrieve the estimation's current ΔT.

Returns

The current value the estimation will default to using if no time delta is provided.

DeltaT() [2/2]

template<typename T >

void scmp::estimation::Madgwick< T >::DeltaT ( T  newDeltaT )

inline

Set the default Δt.

Note

This must be explicitly called before calling any method which uses the estimation's internal Δt.

Parameters

newDeltaT

The time delta to use when no time delta is provided.

Euler()

template<typename T >

scmp::geom::Vector< T, 3 > scmp::estimation::Madgwick< T >::Euler ( )

inline

Retrieve a vector of the Euler angles in ZYX Orientation.

Returns

A vector of Euler angles as <ψ, θ, ϕ>.

Orientation()

template<typename T >

scmp::geom::Quaternion< T > scmp::estimation::Madgwick< T >::Orientation ( ) const

inline

Return the current orientation as measured by the estimation.

Returns

The current sensor frame.

UpdateAngularOrientation() [1/2]

template<typename T >

void scmp::estimation::Madgwick< T >::UpdateAngularOrientation ( const scmp::geom::Vector< T, 3 > &  gyro )

inline

Update the sensor frame with a gyroscope reading.

If no Δt is provided, the estimation's default is used.

Warning

The default Δt must be explicitly set using DeltaT before calling this.

Parameters

gyro	A three-dimensional vector containing gyro readings as w_x, w_y, w_z.

UpdateAngularOrientation() [2/2]

template<typename T >

void scmp::estimation::Madgwick< T >::UpdateAngularOrientation ( const scmp::geom::Vector< T, 3 > &  gyro, T  delta  )

inline

Update the sensor frame with a gyroscope reading.

This method will assert that the Δt value is not zero within a 100μs tolerance. This assert is compiled out with the compile flag NDEBUG, but may be useful to catch possible errors.

Parameters

gyro	A three-dimensional vector containing gyro readings as w_x, w_y, w_z.
delta	The time step between readings. It must not be zero.

UpdateFrame() [1/2]

template<typename T >

void scmp::estimation::Madgwick< T >::UpdateFrame ( const scmp::geom::Quaternion< T > &  sf )

inline

Update the sensor frame to a new frame.

Warning

The estimation's default Δt must be set before calling this.

Parameters

sf	The new sensor frame replacing the previous one.

UpdateFrame() [2/2]

template<typename T >

void scmp::estimation::Madgwick< T >::UpdateFrame ( const scmp::geom::Quaternion< T > &  sf, T  delta  )

inline

Update the sensor frame to a new frame.

Parameters

sf	The new sensor frame replacing the previous one.
delta	The time delta since the last update.

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

• include/scmp/estimation/Madgwick.h