gramods::gmMisc::EFHOAW Class Reference

This is an end-fitting higher-order adaptive window estimator of velocity from samples allowing jittering. More...

#include <EFHOAW.hh>

Classes
struct	Impl

Public Types
typedef Eigen::Matrix< double, 3, Eigen::Dynamic >	polco
	Matrix holding the polynomial coefficients, one row for each dimension.

Public Member Functions
	EFHOAW ()
	Creates a new end-fitting first-order adaptive window estimator using the default parameters.
void	setHistoryLength (size_t N)
	Set how many samples should be saved to be used when estimating the velocity.
size_t	getHistoryLength () const
	Get the number of samples that are saved to be used when estimating the velocity.
void	setHistoryDuration (double t)
	Set how old samples should be saved to be used when estimating the velocity.
double	getHistoryDuration () const
	Get how old samples are saved to be used when estimating the velocity.
double	getLastSampleTime (size_t id)
	Returns the time associated with the last sample associated with the specified id, or -1 if there is no last sample available.
void	addSample (size_t id, Eigen::Vector3d position, double time, bool replace=true)
	Add a position sample.
polco	estimateCoefficients (size_t id, double error, size_t order=2, size_t *samples=nullptr)
	Estimate and return the coefficients of the polynomial, of the specified order, that best fits the data.
Eigen::Vector3d	getPolynomialPosition (int id, double t) const
	Returns the position calculated from the polynomial using the last estimated coefficients, from the previous call to estimateCoefficients.
Eigen::Vector3d	getPolynomialVelocity (int id, double t) const
	Returns the velocity calculated from the polynomial using the last estimated coefficients, from the previous call to estimateCoefficients.
void	cleanup (double time=-1)
	Clean-up old samples and unused ids.

Detailed Description

This is an end-fitting higher-order adaptive window estimator of velocity from samples allowing jittering.

Units of both length and time can be arbitrarily chosen and the velocity will be estimated as distance over time in the same units.

Member Typedef Documentation

polco

typedef Eigen::Matrix<double, 3, Eigen::Dynamic> gramods::gmMisc::EFHOAW::polco

Matrix holding the polynomial coefficients, one row for each dimension.

Constructor & Destructor Documentation

EFHOAW()

gramods::gmMisc::EFHOAW::EFHOAW

(

)

Creates a new end-fitting first-order adaptive window estimator using the default parameters.

Member Function Documentation

addSample()

void gramods::gmMisc::EFHOAW::addSample	(	size_t	id,
		Eigen::Vector3d	position,
		double	time,
		bool	replace = true
	)

Add a position sample.

Each sample is associated to an id and a time. If a new sample is provided with the same id and time as a previously added sample, this new sample will replace the old.

Parameters

[in]	id	The id to add position sample to.
[in]	position	The position value to use as sample.
[in]	time	The time at which the sample was taken.
[in]	replace	If true (default), old samples with the same time will be replaced with this new sample value.

cleanup()

void gramods::gmMisc::EFHOAW::cleanup

(

double

time = -1

)

Clean-up old samples and unused ids.

This function should be called from time to time, for example after calling addSample, to avoid too much unnecessary memory usage.

Parameters

time	The current time, to use when estimating if samples are too old, or -1 to use the samples' time.

estimateCoefficients()

EFHOAW::polco gramods::gmMisc::EFHOAW::estimateCoefficients	(	size_t	id,
		double	error,
		size_t	order = 2,
		size_t *	samples = nullptr
	)

Estimate and return the coefficients of the polynomial, of the specified order, that best fits the data.

This method uses as many samples backwards that gives an estimate within the specified error.

Parameters

[in]	id	The id to estimate velocity for.
[in]	error	An estimate of the position tracking error, used to determine how many samples to include in the averaging.
[in]	order	The order of estimation
[out]	samples	The number of history samples used in the estimation.

Returns

A 3 rows and order+1 column matrix with the polynomial coefficients

getHistoryDuration()

double gramods::gmMisc::EFHOAW::getHistoryDuration

(

)

const

Get how old samples are saved to be used when estimating the velocity.

getHistoryLength()

size_t gramods::gmMisc::EFHOAW::getHistoryLength

(

)

const

Get the number of samples that are saved to be used when estimating the velocity.

getLastSampleTime()

double gramods::gmMisc::EFHOAW::getLastSampleTime

(

size_t

id

)

Returns the time associated with the last sample associated with the specified id, or -1 if there is no last sample available.

getPolynomialPosition()

Eigen::Vector3d gramods::gmMisc::EFHOAW::getPolynomialPosition	(	int	id,
		double	t
	)		const

Returns the position calculated from the polynomial using the last estimated coefficients, from the previous call to estimateCoefficients.

Observe that this method can be used both for inter- and extrapolation.

getPolynomialVelocity()

Eigen::Vector3d gramods::gmMisc::EFHOAW::getPolynomialVelocity	(	int	id,
		double	t
	)		const

Returns the velocity calculated from the polynomial using the last estimated coefficients, from the previous call to estimateCoefficients.

Observe that this method can be used both for inter- and extrapolation.

setHistoryDuration()

void gramods::gmMisc::EFHOAW::setHistoryDuration

(

double

t

)

Set how old samples should be saved to be used when estimating the velocity.

Per default all samples are saved and used.

setHistoryLength()

void gramods::gmMisc::EFHOAW::setHistoryLength

(

size_t

N

)

Set how many samples should be saved to be used when estimating the velocity.

Per default all samples are saved and used.

---

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

• /home/karlu/private/program/gramods/modules/gmMisc/include/gmMisc/EFHOAW.hh
• /home/karlu/private/program/gramods/modules/gmMisc/src/EFHOAW.cpp