rtabmap::IMUFilter Class Reference

Fuses gyroscope and accelerometer samples into an orientation quaternion. More...

#include <IMUFilter.h>

Public Types
enum	Type { kMadgwick = 0 , kComplementaryFilter = 1 }
	Orientation fusion algorithm. More...

Public Member Functions
virtual void	parseParameters (const ParametersMap &parameters)
	Re-reads filter parameters from parameters.
void	update (double gx, double gy, double gz, double ax, double ay, double az, double stamp)
	Integrates one IMU sample and updates the internal orientation estimate.
virtual IMUFilter::Type	type () const =0
virtual void	getOrientation (double &qx, double &qy, double &qz, double &qw) const =0
	Current orientation estimate.
virtual void	reset (double qx=0.0, double qy=0.0, double qz=0.0, double qw=1.0)=0
	Resets internal state to the given orientation.

Static Public Member Functions
static IMUFilter *	create (const ParametersMap &parameters=ParametersMap())
	Creates a filter using type parsed from parameters.
static IMUFilter *	create (IMUFilter::Type type, const ParametersMap &parameters=ParametersMap())
	Creates a filter of the given type.

Protected Member Functions
	IMUFilter (const ParametersMap &parameters=ParametersMap())

Detailed Description

Fuses gyroscope and accelerometer samples into an orientation quaternion.

Implementations integrate angular rates and correct drift using the measured gravity vector. The public update() API takes timestamps and computes the time step between consecutive calls.

Factory methods create() return heap-allocated instances; the caller owns the pointer (e.g. SensorCaptureThread, IMUThread, Camera).

Output orientation from getOrientation() is a unit quaternion (qx, qy, qz, qw) in the same convention as IMU (body frame).

Filter tuning parameters are read from ParametersMap (ImuFilter/... keys); see kComplementaryFilter and kMadgwick (the latter only when RTAB-Map is built with Madgwick support).

See also

IMU

SensorCaptureThread::enableIMUFiltering()

Definition at line 58 of file IMUFilter.h.

Member Enumeration Documentation

Type

enum rtabmap::IMUFilter::Type

Orientation fusion algorithm.

Enumerator
kMadgwick	Madgwick AHRS (attitude and heading reference system). RTAB-Map must be built with Madgwick support.
kComplementaryFilter	Complementary filter (always available).

Definition at line 64 of file IMUFilter.h.

Constructor & Destructor Documentation

~IMUFilter()

virtual rtabmap::IMUFilter::~IMUFilter ( )

inlinevirtual

Definition at line 85 of file IMUFilter.h.

IMUFilter()

rtabmap::IMUFilter::IMUFilter ( const ParametersMap &  parameters = ParametersMap() )

inlineprotected

Definition at line 130 of file IMUFilter.h.

Member Function Documentation

create() [1/2]

static IMUFilter * rtabmap::IMUFilter::create ( const ParametersMap &  parameters = ParametersMap() )

static

Creates a filter using type parsed from parameters.

Parameters

parameters

Optional ImuFilter/... tuning parameters.

Returns

New filter instance (caller owns the pointer).

create() [2/2]

static IMUFilter * rtabmap::IMUFilter::create ( IMUFilter::Type  type, const ParametersMap &  parameters = ParametersMap()  )

static

Creates a filter of the given type.

Parameters

type	Fusion algorithm; falls back to kComplementaryFilter if kMadgwick is requested but not compiled in.
parameters	Optional ImuFilter/... tuning parameters.

Returns

New filter instance (caller owns the pointer).

parseParameters()

virtual void rtabmap::IMUFilter::parseParameters ( const ParametersMap &  parameters )

inlinevirtual

Re-reads filter parameters from parameters.

Parameters

parameters

ImuFilter/... keys (implementation-specific).

Definition at line 91 of file IMUFilter.h.

update()

void rtabmap::IMUFilter::update	(	double	gx,
		double	gy,
		double	gz,
		double	ax,
		double	ay,
		double	az,
		double	stamp
	)

Integrates one IMU sample and updates the internal orientation estimate.

Parameters

gx	Gyroscope x angular rate (rad/s).
gy	Gyroscope y angular rate (rad/s).
gz	Gyroscope z angular rate (rad/s).
ax	Accelerometer x (m/s²; magnitude ~9.81 when stationary).
ay	Accelerometer y (m/s²).
az	Accelerometer z (m/s²).
stamp	Sample time (seconds); used with the previous stamp to compute dt.

type()

virtual IMUFilter::Type rtabmap::IMUFilter::type ( ) const

pure virtual

Returns

Active fusion algorithm type.

getOrientation()

virtual void rtabmap::IMUFilter::getOrientation ( double &  qx, double &  qy, double &  qz, double &  qw  ) const

pure virtual

Current orientation estimate.

Parameters

qx	Quaternion x
qy	Quaternion y
qz	Quaternion z
qw	Quaternion w (scalar)

reset()

virtual void rtabmap::IMUFilter::reset ( double  qx = 0.0, double  qy = 0.0, double  qz = 0.0, double  qw = 1.0  )

pure virtual

Resets internal state to the given orientation.

Parameters

qx	Quaternion x (default 0)
qy	Quaternion y (default 0)
qz	Quaternion z (default 0)
qw	Quaternion w (default 1, identity)

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

• corelib/include/rtabmap/core/IMUFilter.h