xrt::auxiliary::tracking::SimpleIMUFusion Class Reference

A simple IMU fusion class. More...

#include <tracking/t_imu_fusion.hpp>

Public Member Functions
EIGEN_MAKE_ALIGNED_OPERATOR_NEW	SimpleIMUFusion (double gravity_rate=0.9)
bool	valid () const noexcept
Eigen::Quaterniond	getQuat () const
	Get the current state orientation. More...
Eigen::Vector3d	getRotationVec () const
	Get the current state orientation as a rotation vector. More...
Eigen::Matrix3d	getRotationMatrix () const
	Get the current state orientation as a rotation matrix. More...
Eigen::Quaterniond	getPredictedQuat (timepoint_ns timestamp) const
	Get the predicted orientation at some point in the future. More...
Eigen::Vector3d const &	getAngVel () const
	Get the angular velocity in body space. More...
bool	handleGyro (Eigen::Vector3d const &gyro, timepoint_ns timestamp)
	Process a gyroscope report. More...
bool	handleAccel (Eigen::Vector3d const &accel, timepoint_ns timestamp)
	Process an accelerometer report. More...
Eigen::Vector3d	getCorrectedWorldAccel (Eigen::Vector3d const &accel) const
	Use this to obtain the residual, world-space acceleration in m/s/s not associated with gravity, after incorporating a measurement. More...
void	postCorrect ()
	Normalize internal state. More...

Detailed Description

A simple IMU fusion class.

Constructor & Destructor Documentation

SimpleIMUFusion()

EIGEN_MAKE_ALIGNED_OPERATOR_NEW xrt::auxiliary::tracking::SimpleIMUFusion::SimpleIMUFusion ( double  gravity_rate = 0.9 )

inlineexplicit

Parameters

gravity_rate

Value in [0, 1] indicating how much the accelerometer should affect the orientation each second.

Member Function Documentation

getAngVel()

Eigen::Vector3d const & xrt::auxiliary::tracking::SimpleIMUFusion::getAngVel ( ) const

inline

Get the angular velocity in body space.

Referenced by imu_fusion::imu_fusion_get_prediction().

getCorrectedWorldAccel()

Eigen::Vector3d xrt::auxiliary::tracking::SimpleIMUFusion::getCorrectedWorldAccel ( Eigen::Vector3d const &  accel ) const

inline

Use this to obtain the residual, world-space acceleration in m/s/s not associated with gravity, after incorporating a measurement.

Parameters

accel

Body-relative acceleration measurement in m/s/s.

References MATH_GRAVITY_M_S2.

Referenced by imu_fusion::imu_fusion_incorporate_accelerometer(), and imu_fusion::imu_fusion_incorporate_gyros_and_accelerometer().

getPredictedQuat()

Eigen::Quaterniond xrt::auxiliary::tracking::SimpleIMUFusion::getPredictedQuat ( timepoint_ns  timestamp ) const

inline

Get the predicted orientation at some point in the future.

Here, we do not clamp the delta-t, so only ask for reasonable points in the future. (The gyro handler math does clamp delta-t for the purposes of integration in case of long times without signals, etc, which is OK since the accelerometer serves as a correction.)

Referenced by imu_fusion::imu_fusion_get_prediction(), and imu_fusion::imu_fusion_get_prediction_rotation_vec().

getQuat()

Eigen::Quaterniond xrt::auxiliary::tracking::SimpleIMUFusion::getQuat ( ) const

inline

Get the current state orientation.

Referenced by imu_fusion::imu_fusion_get_prediction().

getRotationMatrix()

Eigen::Matrix3d xrt::auxiliary::tracking::SimpleIMUFusion::getRotationMatrix ( ) const

inline

Get the current state orientation as a rotation matrix.

getRotationVec()

Eigen::Vector3d xrt::auxiliary::tracking::SimpleIMUFusion::getRotationVec ( ) const

inline

Get the current state orientation as a rotation vector.

Referenced by imu_fusion::imu_fusion_get_prediction_rotation_vec().

handleAccel()

bool xrt::auxiliary::tracking::SimpleIMUFusion::handleAccel ( Eigen::Vector3d const &  accel, timepoint_ns  timestamp  )

inline

Process an accelerometer report.

Parameters

accel	Body-relative acceleration measurement in m/s/s.
timestamp	Nanosecond timestamp of this measurement.

Returns

true if the report was used to update the state.

Referenced by imu_fusion::imu_fusion_incorporate_accelerometer(), and imu_fusion::imu_fusion_incorporate_gyros_and_accelerometer().

handleGyro()

bool xrt::auxiliary::tracking::SimpleIMUFusion::handleGyro ( Eigen::Vector3d const &  gyro, timepoint_ns  timestamp  )

inline

Process a gyroscope report.

Note

At startup, no gyro reports will be considered until at least one accelerometer report has been processed, to provide us with an initial estimate of the direction of gravity.

Parameters

gyro	Angular rate in radians per second, in body space.
timestamp	Nanosecond timestamp of this measurement.

Returns

true if the report was used to update the state.

Referenced by imu_fusion::imu_fusion_incorporate_gyros(), and imu_fusion::imu_fusion_incorporate_gyros_and_accelerometer().

postCorrect()

void xrt::auxiliary::tracking::SimpleIMUFusion::postCorrect ( )

inline

Normalize internal state.

Call periodically, like after you finish handling both the accel and gyro from one packet.

Referenced by imu_fusion::imu_fusion_incorporate_gyros_and_accelerometer().

valid()

bool xrt::auxiliary::tracking::SimpleIMUFusion::valid ( ) const

inlinenoexcept

Returns

true if the filter has started up

Referenced by imu_fusion::imu_fusion_get_prediction(), and imu_fusion::imu_fusion_get_prediction_rotation_vec().

---

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

• auxiliary/tracking/t_imu_fusion.hpp