warpos::EkfMeasurementUpdate< N, M, O > Class Template Reference

Generic, templated EKF measurement update class. More...

#include <EkfMeasurementUpdate.hpp>

Public Member Functions
	EkfMeasurementUpdate (Measurements< N, M, O > &measurement_ref)
	Constructor.
int16	generateResidual (floating_point time, const std::array< floating_point, N > &state_minus, const std::array< floating_point, O > &obs_state, const std::array< floating_point, M > &measurement, std::array< floating_point, M > *residual)
	Function to generate the residual from the current state.
int16	runUpdate (floating_point time, const std::array< floating_point, N > &state_minus, const clockwerk::Matrix< N, N > &cov_minus, const std::array< floating_point, O > &obs_state, const std::array< floating_point, M > &residual, std::array< floating_point, N > *state_plus, clockwerk::Matrix< N, N > *cov_plus)
	Function to perform state measurement update in EKF.
void	setMeasurementNoiseMatrix (const clockwerk::Matrix< M, M > &R)
	Set the R matrix for the measurement update.

Detailed Description

template<uint32 N, uint32 M, uint32 O>
class warpos::EkfMeasurementUpdate< N, M, O >

Generic, templated EKF measurement update class.

This class performs an EKF measurement update using the current target state, an "observer state" which provides information (i.e. ground station information), and the associated measurement and H matrix functions. It requires three templated arguments, which are as follows: N - The number of target states estimated in the EKF M - The number of measurement states provided. Same as the number of noise states. O - The number of observer states used to support measurement generation

The measurement update is performed based on the Joseph formulation of the Kalman update for numerical stability. Symmetry is enforced every step.

The measurement update enforces positive diagonal on the covariance matrix prior to processing. If the matrix has any items below the minimum epsilon on the diagonal, the minimum epsilon is enforced.

Author: James Tabony james.nosp@m..tab.nosp@m.ony@a.nosp@m.ttx..nosp@m.tech / Alex Reynolds

Constructor & Destructor Documentation

EkfMeasurementUpdate()

template<uint32 N, uint32 M, uint32 O>

warpos::EkfMeasurementUpdate< N, M, O >::EkfMeasurementUpdate

(

Measurements< N, M, O > &

measurement_ref

)

Constructor.

Member Function Documentation

generateResidual()

template<uint32 N, uint32 M, uint32 O>

int16 warpos::EkfMeasurementUpdate< N, M, O >::generateResidual	(	floating_point	time,
		const std::array< floating_point, N > &	state_minus,
		const std::array< floating_point, O > &	obs_state,
		const std::array< floating_point, M > &	measurement,
		std::array< floating_point, M > *	residual )

Function to generate the residual from the current state.

Parameters

[in]	time	The reference time
[in]	state_minus	The system prior to measurement update
[in]	obs_state	The observer state ar the reference time
[in]	measurement	The actual measurement derived from the sensors
[out]	residual	Implicit return of the difference (actual measurement - expected measurement)

Returns

Error code corresponding to success/failure

runUpdate()

template<uint32 N, uint32 M, uint32 O>

int16 warpos::EkfMeasurementUpdate< N, M, O >::runUpdate	(	floating_point	time,
		const std::array< floating_point, N > &	state_minus,
		const clockwerk::Matrix< N, N > &	cov_minus,
		const std::array< floating_point, O > &	obs_state,
		const std::array< floating_point, M > &	residual,
		std::array< floating_point, N > *	state_plus,
		clockwerk::Matrix< N, N > *	cov_plus )

Function to perform state measurement update in EKF.

Parameters

[in]	time	The reference time
[in]	state_minus	The system state prior to measurement update
[in]	cov_minus	The system covariance prior to measurement update
[in]	obs_state	The observer state at the reference time
[in]	residual	The difference (actual measurement - expected measurement)
[out]	state_plus	Implicit return of the state of the system after measurement update
[out]	cov_plus	Implicit return of the covariance of the system after measurement update

Returns

Error code corresponding to success/failure

setMeasurementNoiseMatrix()

template<uint32 N, uint32 M, uint32 O>

void warpos::EkfMeasurementUpdate< N, M, O >::setMeasurementNoiseMatrix ( const clockwerk::Matrix< M, M > & R )

inline

Set the R matrix for the measurement update.

Parameters

R	The measurement noise matrix to set

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

• /Users/mickey/Documents/Projects/warptwin/warpos/src/gncutils/EKF/EkfMeasurementUpdate.hpp