State of the inverted pendulum model. More...

#include <lipm_walking/Pendulum.h>

Public Member Functions
EIGEN_MAKE_ALIGNED_OPERATOR_NEW	Pendulum (const Eigen::Vector3d &com=Eigen::Vector3d::Zero(), const Eigen::Vector3d &comd=Eigen::Vector3d::Zero(), const Eigen::Vector3d &comdd=Eigen::Vector3d::Zero())
	Initialize state from CoM position and its derivatives. More...

void	completeIPM (const Contact &plane)
	Complete inverted pendulum inputs (ZMP and natural frequency) from contact plane. More...

void	integrateCoMJerk (const Eigen::Vector3d &comddd, double dt)
	Integrate constant CoM jerk for a given duration. More...

void	integrateIPM (Eigen::Vector3d zmp, double lambda, double dt)
	Integrate in floating-base inverted pendulum mode with constant inputs. More...

void	reset (const Eigen::Vector3d &com, const Eigen::Vector3d &comd=Eigen::Vector3d::Zero(), const Eigen::Vector3d &comdd=Eigen::Vector3d::Zero())
	Reset to a new state from CoM position and its derivatives. More...

void	resetCoMHeight (double height, const Contact &contact)
	Reset CoM height above a given contact plane. More...

const Eigen::Vector3d &	com () const
	CoM position in the world frame. More...

const Eigen::Vector3d &	comd () const
	CoM velocity in the world frame. More...

const Eigen::Vector3d &	comdd () const
	CoM acceleration in the world frame. More...

Eigen::Vector3d	dcm () const
	Divergent component of motion. More...

double	omega () const
	Natural frequency. More...

const Eigen::Vector3d &	zmp () const
	Zero-tilting moment point. More...

const Eigen::Vector3d &	zmpd () const
	Velocity of the zero-tilting moment point. More...

Protected Attributes
Eigen::Vector3d	com_
	Position of the center of mass. More...

Eigen::Vector3d	comd_
	Velocity of the center of mass. More...

Eigen::Vector3d	comdd_
	Acceleration of the center of mass. More...

Eigen::Vector3d	comddd_
	Jerk of the center of mass. More...

Eigen::Vector3d	zmp_
	Position of the zero-tilting moment point. More...

Eigen::Vector3d	zmpd_
	Velocity of the zero-tilting moment point. More...

double	omega_
	Natural frequency in [Hz]. More...

Detailed Description

State of the inverted pendulum model.

Definition at line 40 of file Pendulum.h.

Constructor & Destructor Documentation

lipm_walking::Pendulum::Pendulum	(	const Eigen::Vector3d &	com = `Eigen::Vector3d::Zero()`,
		const Eigen::Vector3d &	comd = `Eigen::Vector3d::Zero()`,
		const Eigen::Vector3d &	comdd = `Eigen::Vector3d::Zero()`
	)

Initialize state from CoM position and its derivatives.

Parameters

com	CoM position.
comd	CoM velocity.
comdd	CoM acceleration.

Definition at line 34 of file Pendulum.cpp.

Member Function Documentation

const Eigen::Vector3d& lipm_walking::Pendulum::com ( ) const

inline

CoM position in the world frame.

Definition at line 112 of file Pendulum.h.

const Eigen::Vector3d& lipm_walking::Pendulum::comd ( ) const

inline

CoM velocity in the world frame.

Definition at line 120 of file Pendulum.h.

const Eigen::Vector3d& lipm_walking::Pendulum::comdd ( ) const

inline

CoM acceleration in the world frame.

Definition at line 128 of file Pendulum.h.

void lipm_walking::Pendulum::completeIPM ( const Contact & plane )

Complete inverted pendulum inputs (ZMP and natural frequency) from contact plane.

Parameters

plane Contact plane in which the ZMP is considered.

Note: The current CoM position and acceleration are used to compute the ZMP in the desired plane.

Definition at line 88 of file Pendulum.cpp.

Eigen::Vector3d lipm_walking::Pendulum::dcm ( ) const

inline

Divergent component of motion.

Definition at line 136 of file Pendulum.h.

void lipm_walking::Pendulum::integrateCoMJerk	(	const Eigen::Vector3d &	comddd,
		double	dt
	)

Integrate constant CoM jerk for a given duration.

Parameters

comddd	CoM jerk.
dt	Integration step.

Definition at line 71 of file Pendulum.cpp.

void lipm_walking::Pendulum::integrateIPM	(	Eigen::Vector3d	zmp,
		double	lambda,
		double	dt
	)

Integrate in floating-base inverted pendulum mode with constant inputs.

Parameters

zmp	Zero-tilting Moment Point, i.e. net force application point.
lambda	Normalized stiffness of the pendulum.
dt	Duration of integration step.

Definition at line 52 of file Pendulum.cpp.

double lipm_walking::Pendulum::omega ( ) const

inline

Natural frequency.

Definition at line 144 of file Pendulum.h.

void lipm_walking::Pendulum::reset	(	const Eigen::Vector3d &	com,
		const Eigen::Vector3d &	comd = `Eigen::Vector3d::Zero()`,
		const Eigen::Vector3d &	comdd = `Eigen::Vector3d::Zero()`
	)

Reset to a new state from CoM position and its derivatives.

Parameters

com	CoM position.
comd	CoM velocity.
comdd	CoM acceleration.

Definition at line 39 of file Pendulum.cpp.

void lipm_walking::Pendulum::resetCoMHeight	(	double	height,
		const Contact &	contact
	)

Reset CoM height above a given contact plane.

Parameters

height	CoM height above contact plane.
contact	Contact plane.

Definition at line 79 of file Pendulum.cpp.

const Eigen::Vector3d& lipm_walking::Pendulum::zmp ( ) const

inline

Zero-tilting moment point.

Note: In the linear inverted pendulum mode, the ZMP coincides with the centroidal moment pivot (CMP) or its extended version (eCMP).

Definition at line 155 of file Pendulum.h.

const Eigen::Vector3d& lipm_walking::Pendulum::zmpd ( ) const

inline

Velocity of the zero-tilting moment point.

Definition at line 163 of file Pendulum.h.

Member Data Documentation

Eigen::Vector3d lipm_walking::Pendulum::com_

protected

Position of the center of mass.

Definition at line 169 of file Pendulum.h.

Eigen::Vector3d lipm_walking::Pendulum::comd_

protected

Velocity of the center of mass.

Definition at line 170 of file Pendulum.h.

Eigen::Vector3d lipm_walking::Pendulum::comdd_

protected

Acceleration of the center of mass.

Definition at line 171 of file Pendulum.h.

Eigen::Vector3d lipm_walking::Pendulum::comddd_

protected

Jerk of the center of mass.

Definition at line 172 of file Pendulum.h.

double lipm_walking::Pendulum::omega_

protected

Natural frequency in [Hz].

Definition at line 175 of file Pendulum.h.

Eigen::Vector3d lipm_walking::Pendulum::zmp_

protected

Position of the zero-tilting moment point.

Definition at line 173 of file Pendulum.h.

Eigen::Vector3d lipm_walking::Pendulum::zmpd_

protected

Velocity of the zero-tilting moment point.

Definition at line 174 of file Pendulum.h.

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation