1D version of the estimation of a bias betweeen the divergent component of motion and the corresponding zero moment point for a linearized inverted pendulum model. More...

#include <unidim-lipm-dcm-estimator.hpp>

Public Member Functions
	UnidimLipmDcmEstimator (double dt=defaultDt_, double omega_0=defaultOmega_, double biasDriftPerSecondStd=defaultBiasDriftSecond, double initDcm=0, double initZMP=0, double initBias=0, double dcmMeasureErrorStd=defaultDcmErrorStd, double zmpMeasureErrorStd=defaultZmpErrorStd, double initDcmUncertainty=defaultDCMUncertainty, double initBiasUncertainty=defaultBiasUncertainty)
	Construct a new Unidimensional Lipm Dcm Estimator.
void	resetWithInputs (double measuredDcm, double measuredZMP, bool measurementIsWithBias=true, double biasDriftPerSecondStd=defaultBiasDriftSecond, double dcmMeasureErrorStd=defaultDcmErrorStd, double zmpMeasureErrorStd=defaultZmpErrorStd, double initBias=0, double initBiasuncertainty=defaultBiasUncertainty)
	Construct a new Lipm Dcm Bias Estimator object.
	~UnidimLipmDcmEstimator ()
	Destroy the Lipm Dcm Bias Estimator object.
void	setLipmNaturalFrequency (double omega_0)
	Set the Lipm Natural Frequency.
void	setSamplingTime (double dt)
	Set the Sampling Time.
void	setBias (double bias)
	Set the Bias object from a guess.
void	setBias (double bias, double uncertainty)
	Set the Bias object from a guess.
void	setBiasDriftPerSecond (double driftPerSecond)
	Set the Bias Drift Per Second.
void	setUnbiasedDCM (double dcm)
	set the real DCM position from a guess
void	setUnbiasedDCM (double dcm, double uncertainty)
	set the real DCM position from a guess
void	setZmpMeasureErrorStd (double)
	Set the Zmp Measurement Error Stamdard devbiation.
void	setDcmMeasureErrorStd (double)
	Set the Dcm Measurement Error Standard.
void	setInputs (double dcm, double zmp)
	Set the Inputs of the estimator.
Vector2	update ()
	Runs the estimation. Needs to be called every timestep.
double	getUnbiasedDCM () const
	Get the Unbiased DCM filtered by the estimator.
double	getBias () const
	Get the estimated Bias.
LinearKalmanFilter &	getFilter ()
	Get the Kalman Filter object This can be used to run specific Advanced Kalman filter related funcions.
const LinearKalmanFilter &	getFilter () const
	Get the Kalman Filter object This can be used to run specific Advanced Kalman filter related funcions.

Static Public Attributes
static constexpr double	defaultBiasDriftSecond = 0.002
	default expected drift of the bias every second
static constexpr double	defaultZmpErrorStd = 0.005
	default error in the estimation of the sensors
static constexpr double	defaultDcmErrorStd = 0.01
static constexpr double	defaultDCMUncertainty = 0.01
	default uncertainty in the initial values of DCM and Bias
static constexpr double	defaultBiasUncertainty = 0.01

Detailed Description

1D version of the estimation of a bias betweeen the divergent component of motion and the corresponding zero moment point for a linearized inverted pendulum model.

A humanoid robot can be modeled as an inverted pendulum. The dynamics can be linearized to obtain a dynamics with a convergent and a divergent component of motion (DCN). The dynamics of the DCM depends on the Zero Moment Point. The DCM can be measured using the CoM and its velocity, but the CoM position can be biased. This estimator uses Kalman Filtering to estimate this bias in one axis.

Definition at line 34 of file unidim-lipm-dcm-estimator.hpp.

Constructor & Destructor Documentation

◆ UnidimLipmDcmEstimator()

stateObservation::UnidimLipmDcmEstimator::UnidimLipmDcmEstimator	(	double	dt = defaultDt_,
		double	omega_0 = defaultOmega_,
		double	biasDriftPerSecondStd = defaultBiasDriftSecond,
		double	initDcm = 0,
		double	initZMP = 0,
		double	initBias = 0,
		double	dcmMeasureErrorStd = defaultDcmErrorStd,
		double	zmpMeasureErrorStd = defaultZmpErrorStd,
		double	initDcmUncertainty = defaultDCMUncertainty,
		double	initBiasUncertainty = defaultBiasUncertainty )

Construct a new Unidimensional Lipm Dcm Estimator.

Parameters

dt	the sampling time in seconds
omega_0	the natural frequency of the DCM (rad/s)
biasDriftPerSecondStd	the standard deviation of the drift (m/s)
initDcm	the initial value of the DCM
initZMP	the initial value of the ZMP
initBias	the initial value of the bias
dcmMeasureErrorStd	the standard deviation of the dcm estimation error, NOT including the bias (m)
zmpMeasureErrorStd	the standard deviaiton of the zmp estimation error (m)
initDcmUncertainty	the uncertainty in the DCM initial value in meters
initBiasUncertainty	the uncertainty in the bias initial value in meters

◆ ~UnidimLipmDcmEstimator()

stateObservation::UnidimLipmDcmEstimator::~UnidimLipmDcmEstimator ( )

inline

Destroy the Lipm Dcm Bias Estimator object.

Definition at line 98 of file unidim-lipm-dcm-estimator.hpp.

Member Function Documentation

◆ resetWithInputs()

void stateObservation::UnidimLipmDcmEstimator::resetWithInputs	(	double	measuredDcm,
		double	measuredZMP,
		bool	measurementIsWithBias = true,
		double	biasDriftPerSecondStd = defaultBiasDriftSecond,
		double	dcmMeasureErrorStd = defaultDcmErrorStd,
		double	zmpMeasureErrorStd = defaultZmpErrorStd,
		double	initBias = 0,
		double	initBiasuncertainty = defaultBiasUncertainty )

Construct a new Lipm Dcm Bias Estimator object.

Use this when initializing with an available DCM (biased) measurement

Parameters

measurementIsWithBias	sets if yes or no the measurement is with the bias. It is better set to true than trying to remove it beforehand
measuredDcm	the the measured position of the DCM
omega_0	the natural frequency of the DCM (rad/s)
dt	the sampling time in seconds
biasDriftPerSecondStd	the standard deviation of the drift (m/s)
zmpMeasureErrorStd	the standard deviaiton of the zmp estimation error (m)
scmMeasureErrorStd	the standard deviation of the dcm estimation error, NOT including the bias (m)
initBias	the initial value of the drift
initBiasUncertainty	the uncertainty in the bias initial value in meters

◆ setLipmNaturalFrequency()

void stateObservation::UnidimLipmDcmEstimator::setLipmNaturalFrequency ( double omega_0 )

Set the Lipm Natural Frequency.

Parameters

omega_0 is the sampling time in seconds

◆ setSamplingTime()

void stateObservation::UnidimLipmDcmEstimator::setSamplingTime ( double dt )

Set the Sampling Time.

Parameters

dt	sampling time

◆ setBias() [1/2]

void stateObservation::UnidimLipmDcmEstimator::setBias ( double bias )

Set the Bias object from a guess.

Parameters

bias guess

◆ setBias() [2/2]

void stateObservation::UnidimLipmDcmEstimator::setBias	(	double	bias,
		double	uncertainty )

Set the Bias object from a guess.

Parameters

bias	guess
the	uncertainty you have in this guess in meters

◆ setBiasDriftPerSecond()

void stateObservation::UnidimLipmDcmEstimator::setBiasDriftPerSecond ( double driftPerSecond )

Set the Bias Drift Per Second.

Parameters

driftPerSecond the standard deviation of the drift (m/s)

◆ setUnbiasedDCM() [1/2]

void stateObservation::UnidimLipmDcmEstimator::setUnbiasedDCM ( double dcm )

set the real DCM position from a guess

Parameters

dcm guess

◆ setUnbiasedDCM() [2/2]

void stateObservation::UnidimLipmDcmEstimator::setUnbiasedDCM	(	double	dcm,
		double	uncertainty )

set the real DCM position from a guess

Parameters

dcm	guess
dcm
uncertainty	the uncertainty in this guess

◆ setInputs()

void stateObservation::UnidimLipmDcmEstimator::setInputs	(	double	dcm,
		double	zmp )

Set the Inputs of the estimator.

Parameters

dcm
zmp

◆ update()

Vector2 stateObservation::UnidimLipmDcmEstimator::update ( )

inline

Runs the estimation. Needs to be called every timestep.

Returns: Vector2

Definition at line 153 of file unidim-lipm-dcm-estimator.hpp.

◆ getUnbiasedDCM()

double stateObservation::UnidimLipmDcmEstimator::getUnbiasedDCM ( ) const

Get the Unbiased DCM filtered by the estimator.

@detailt This is the recommended output to take

Returns: double

◆ getBias()

double stateObservation::UnidimLipmDcmEstimator::getBias ( ) const

Get the estimated Bias.

Returns: double

◆ getFilter() [1/2]

LinearKalmanFilter & stateObservation::UnidimLipmDcmEstimator::getFilter ( )

inline

Get the Kalman Filter object This can be used to run specific Advanced Kalman filter related funcions.

Returns: LinearKalmanFilter&

Definition at line 172 of file unidim-lipm-dcm-estimator.hpp.

◆ getFilter() [2/2]

const LinearKalmanFilter & stateObservation::UnidimLipmDcmEstimator::getFilter ( ) const

inline

Get the Kalman Filter object This can be used to run specific Advanced Kalman filter related funcions.

Returns: LinearKalmanFilter& const version

Definition at line 179 of file unidim-lipm-dcm-estimator.hpp.

Member Data Documentation

◆ defaultBiasDriftSecond

double stateObservation::UnidimLipmDcmEstimator::defaultBiasDriftSecond = 0.002

staticconstexpr

default expected drift of the bias every second

Definition at line 42 of file unidim-lipm-dcm-estimator.hpp.

◆ defaultZmpErrorStd

double stateObservation::UnidimLipmDcmEstimator::defaultZmpErrorStd = 0.005

staticconstexpr

default error in the estimation of the sensors

Definition at line 45 of file unidim-lipm-dcm-estimator.hpp.

◆ defaultDcmErrorStd

double stateObservation::UnidimLipmDcmEstimator::defaultDcmErrorStd = 0.01

staticconstexpr

Definition at line 46 of file unidim-lipm-dcm-estimator.hpp.

◆ defaultDCMUncertainty

double stateObservation::UnidimLipmDcmEstimator::defaultDCMUncertainty = 0.01

staticconstexpr

default uncertainty in the initial values of DCM and Bias

Definition at line 49 of file unidim-lipm-dcm-estimator.hpp.

◆ defaultBiasUncertainty

double stateObservation::UnidimLipmDcmEstimator::defaultBiasUncertainty = 0.01

staticconstexpr

Definition at line 50 of file unidim-lipm-dcm-estimator.hpp.

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

/build/source/include/state-observation/dynamics-estimators/unidim-lipm-dcm-estimator.hpp

Public Member Functions

Static Public Attributes

Detailed Description

Constructor & Destructor Documentation

◆ UnidimLipmDcmEstimator()

◆ ~UnidimLipmDcmEstimator()

Member Function Documentation

◆ resetWithInputs()

◆ setLipmNaturalFrequency()

◆ setSamplingTime()

◆ setBias() [1/2]

◆ setBias() [2/2]

◆ setBiasDriftPerSecond()

◆ setUnbiasedDCM() [1/2]

◆ setUnbiasedDCM() [2/2]

◆ setInputs()

◆ update()

◆ getUnbiasedDCM()

◆ getBias()

◆ getFilter() [1/2]

◆ getFilter() [2/2]

Member Data Documentation

◆ defaultBiasDriftSecond

◆ defaultZmpErrorStd

◆ defaultDcmErrorStd

◆ defaultDCMUncertainty

◆ defaultBiasUncertainty