clockwerk::EkfMeasurementUpdate< T, N, M, O > Class Template Reference

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

#include <EkfMeasurementUpdate.hpp>

Collaboration diagram for clockwerk::EkfMeasurementUpdate< T, N, M, O >:

Public Member Functions
int	generateResidualHMatrix (const std::array< T, N > &state, const std::array< T, O > &obs_state, const std::array< T, M > &measurement, CartesianVector< T, M > *residual, Matrix< T, M, N > *H)
	Function to generate residual and H matrix from current state.
int	updateState (const CartesianVector< T, M > &residual, const Matrix< T, M, N > &H, const std::array< T, N > &state_minus, const Matrix< T, N, N > &cov_minus, const Matrix< T, M, M > &meas_cov, std::array< T, N > *state_plus, Matrix< T, N, N > *cov_plus)
	Function to perform state measurement update in EKF.
int	calculateMeasurementCovariance (const Matrix< T, M, N > &H, const Matrix< T, N, N > &state_cov, const Matrix< T, M, M > &meas_cov, Matrix< T, M, M > *residual_cov)
	Function to generate covariance for measurement update evaluation.

Public Attributes
Measurements< T, N, M, O > *	measurement_ptr = nullptr
	Pointer to the measurement class to calculate the estimated measurement given the current state of the object. The measurement class should be configured to use size.
Measurements< T, N, M *N, O > *	H_ptr = nullptr
	Pointer to the measurement class to calculate the H matrix from the estimated spacecraft state.

Detailed Description

template<typename T, unsigned int N, unsigned int M, unsigned int O>
class clockwerk::EkfMeasurementUpdate< T, 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 O - The number of observer states used to support measurement generation

Two "functions" which take the form of a Measurements class must also be set: The function which generates measurements, and the function which generates the H matrix.

To run the measurement update, both functions are required. The first generates measurement residuals, and the second to actuall provide the state update

Member Function Documentation

calculateMeasurementCovariance()

template<typename T , unsigned int N, unsigned int M, unsigned int O>

int clockwerk::EkfMeasurementUpdate< T, N, M, O >::calculateMeasurementCovariance	(	const Matrix< T, M, N > &	H,
		const Matrix< T, N, N > &	state_cov,
		const Matrix< T, M, M > &	meas_cov,
		Matrix< T, M, M > *	residual_cov
	)

Function to generate covariance for measurement update evaluation.

Parameters

H	The measurement sensitivity matrix for the system
state_cov	The covariance in the system state
meas_cov	The covariance associated with the measurement
residual_cov	Implicit return of the expected covariance of the residual

Returns

Error code corresponding to success/failure

generateResidualHMatrix()

template<typename T , unsigned int N, unsigned int M, unsigned int O>

int clockwerk::EkfMeasurementUpdate< T, N, M, O >::generateResidualHMatrix	(	const std::array< T, N > &	state,
		const std::array< T, O > &	obs_state,
		const std::array< T, M > &	measurement,
		CartesianVector< T, M > *	residual,
		Matrix< T, M, N > *	H
	)

Function to generate residual and H matrix from current state.

Parameters

state	The current state of the filter
obs_state	An observer state used to generate measurements
measurement	The actual measurement derived from sensors
residual	Implicit return of the difference measurement - estimated measurement
H	Implicit return of the measurement sensitivity matrix for the system

Returns

Error code corresponding to success/failure

updateState()

template<typename T , unsigned int N, unsigned int M, unsigned int O>

int clockwerk::EkfMeasurementUpdate< T, N, M, O >::updateState	(	const CartesianVector< T, M > &	residual,
		const Matrix< T, M, N > &	H,
		const std::array< T, N > &	state_minus,
		const Matrix< T, N, N > &	cov_minus,
		const Matrix< T, M, M > &	meas_cov,
		std::array< T, N > *	state_plus,
		Matrix< T, N, N > *	cov_plus
	)

Function to perform state measurement update in EKF.

Parameters

residual	The difference measurement - estimated measurement
H	The measurement sensitivity matrix for the system
state_minus	The system state prior to measurement update
cov_minus	The system covariance prior to measurement update
meas_cov	The covariance of the measurement
state_plus	Implicit return of the state of the system after measurement update
cov_plus	Implicit return of the covariance of the system after measurement update

Returns

Error code corresponding to success/failure

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

• /home/mickey/modelspace/clockwerk/src/gnc/navigation/ekf/EkfMeasurementUpdate.hpp