Model predictive control problem. More...

#include <lipm_walking/ModelPredictiveControl.h>

Public Member Functions
	ModelPredictiveControl ()
	Initialize new problem. More...

void	addGUIElements (std::shared_ptr< mc_rtc::gui::StateBuilder > gui)
	Add GUI panel. More...

void	addLogEntries (mc_rtc::Logger &logger)
	Log stabilizer entries. More...

void	configure (const mc_rtc::Configuration &)
	Read configuration from dictionary. More...

void	phaseDurations (double initSupportDuration, double doubleSupportDuration, double targetSupportDuration)
	Set duration of the initial single-support phase. More...

bool	buildAndSolve ()
	Build and solve the model predictive control quadratic program. More...

void	comHeight (double height)
	Set CoM height. More...

void	contacts (Contact initContact, Contact targetContact, Contact nextContact)
	Reset contacts. More...

void	initState (const Pendulum &pendulum)
	Set the initial CoM state. More...

unsigned	indexToHrep (unsigned i) const
	Get index of inequality constraints. More...

const Contact &	initContact () const
	Support contact in the first single-support phase. More...

unsigned	nbInitSupportSteps () const
	Number of sampling steps in the preview spent in the first single-support phase. More...

unsigned	nbDoubleSupportSteps () const
	Number of sampling steps in the preview spent in the first double-support phase. More...

const Contact &	nextContact () const
	Support contact in the third single-support phase. More...

void	sole (const Sole &sole)
	Set model sole properties. More...

const std::shared_ptr< Preview >	solution () const
	Get solution vector. More...

const Contact &	targetContact () const
	Support contact in the second single-support phase. More...

Public Attributes
Eigen::Vector2d	velWeights = {10., 10.}
	Weights of CoM velocity tracking cost. More...

double	jerkWeight = 1.
	Weight of CoM jerk regularization cost. More...

double	zmpWeight = 1000.
	Weight of reference ZMP tracking cost. More...

Static Public Attributes
static EIGEN_MAKE_ALIGNED_OPERATOR_NEW constexpr double	SAMPLING_PERIOD = 0.1
	Duration of each sampling step in [s]. More...

static constexpr unsigned	INPUT_SIZE = 2
	Input is the 2D horizontal CoM jerk. More...

static constexpr unsigned	NB_STEPS = 16
	Number of sampling steps. More...

static constexpr unsigned	STATE_SIZE = 6
	State is the 6D stacked vector of CoM positions, velocities and accelerations. More...

Detailed Description

Model predictive control problem.

This implementation is based on "Trajectory free linear model predictive control for stable walking in the presence of strong perturbations" (Wieber, Humanoids 2006) with the addition of terminal constraints.

Definition at line 52 of file ModelPredictiveControl.h.

Constructor & Destructor Documentation

lipm_walking::ModelPredictiveControl::ModelPredictiveControl ( )

Initialize new problem.

Definition at line 44 of file ModelPredictiveControl.cpp.

Member Function Documentation

void lipm_walking::ModelPredictiveControl::addGUIElements ( std::shared_ptr< mc_rtc::gui::StateBuilder > gui )

Add GUI panel.

Parameters

gui	GUI handle.

Definition at line 87 of file ModelPredictiveControl.cpp.

void lipm_walking::ModelPredictiveControl::addLogEntries ( mc_rtc::Logger & logger )

Log stabilizer entries.

Parameters

logger Logger.

Definition at line 129 of file ModelPredictiveControl.cpp.

bool lipm_walking::ModelPredictiveControl::buildAndSolve ( )

Build and solve the model predictive control quadratic program.

Returns: solutionFound Did the solver find a solution?

Definition at line 329 of file ModelPredictiveControl.cpp.

void lipm_walking::ModelPredictiveControl::comHeight ( double height )

inline

Set CoM height.

Parameters

height CoM height above contacts.

Definition at line 118 of file ModelPredictiveControl.h.

void lipm_walking::ModelPredictiveControl::configure ( const mc_rtc::Configuration & config )

Read configuration from dictionary.

Definition at line 76 of file ModelPredictiveControl.cpp.

void lipm_walking::ModelPredictiveControl::contacts	(	Contact	initContact,
		Contact	targetContact,
		Contact	nextContact
	)

inline

Reset contacts.

Parameters

initContact	Contact used during single-support phase.
targetContact	Contact used during double-support phases.
nextContact	Contact coming after targetContact in the plan.

Definition at line 141 of file ModelPredictiveControl.h.

unsigned lipm_walking::ModelPredictiveControl::indexToHrep ( unsigned i ) const

inline

Get index of inequality constraints.

Parameters

i	Timestep in preview horizon.

Returns: hrepIndex Index of corresponding ZMP H-rep.

Note: Inequality constraints are the halfspace representation (H-rep) of a polyhedron. In this class we call them H-rep for short.

Definition at line 169 of file ModelPredictiveControl.h.

const Contact& lipm_walking::ModelPredictiveControl::initContact ( ) const

inline

Support contact in the first single-support phase.

Definition at line 177 of file ModelPredictiveControl.h.

void lipm_walking::ModelPredictiveControl::initState ( const Pendulum & pendulum )

inline

Set the initial CoM state.

Parameters

pendulum CoM state.

Definition at line 153 of file ModelPredictiveControl.h.

unsigned lipm_walking::ModelPredictiveControl::nbDoubleSupportSteps ( ) const

inline

Number of sampling steps in the preview spent in the first double-support phase.

Definition at line 196 of file ModelPredictiveControl.h.

unsigned lipm_walking::ModelPredictiveControl::nbInitSupportSteps ( ) const

inline

Number of sampling steps in the preview spent in the first single-support phase.

Definition at line 186 of file ModelPredictiveControl.h.

const Contact& lipm_walking::ModelPredictiveControl::nextContact ( ) const

inline

Support contact in the third single-support phase.

Definition at line 204 of file ModelPredictiveControl.h.

void lipm_walking::ModelPredictiveControl::phaseDurations	(	double	initSupportDuration,
		double	doubleSupportDuration,
		double	targetSupportDuration
	)

Set duration of the initial single-support phase.

Parameters

initSupportDuration	First SSP duration.
doubleSupportDuration	First DSP duration.
targetSupportDuration	Second SSP duration.

Phase durations don't have to sum up to the total duration of the preview horizon.

If their sum is below total duration, there are two outcomes: if there is a target support phase, a second DSP phase is added from the target contact to the next (full preview mode); otherwise, the first DSP phase is extended until the end of the preview horizon (half preview mode).

If their sum exceeds total duration, phase durations are trimmed starting from the last one.

Definition at line 140 of file ModelPredictiveControl.cpp.

void lipm_walking::ModelPredictiveControl::sole ( const Sole & sole )

inline

Set model sole properties.

Parameters

sole	Sole parameters.

Definition at line 214 of file ModelPredictiveControl.h.

const std::shared_ptr<Preview> lipm_walking::ModelPredictiveControl::solution ( ) const

inline

Get solution vector.

Definition at line 222 of file ModelPredictiveControl.h.

const Contact& lipm_walking::ModelPredictiveControl::targetContact ( ) const

inline

Support contact in the second single-support phase.

Definition at line 230 of file ModelPredictiveControl.h.

Member Data Documentation

constexpr unsigned lipm_walking::ModelPredictiveControl::INPUT_SIZE = 2

static

Input is the 2D horizontal CoM jerk.

Definition at line 57 of file ModelPredictiveControl.h.

double lipm_walking::ModelPredictiveControl::jerkWeight = 1.

Weight of CoM jerk regularization cost.

Definition at line 250 of file ModelPredictiveControl.h.

constexpr unsigned lipm_walking::ModelPredictiveControl::NB_STEPS = 16

static

Number of sampling steps.

Definition at line 58 of file ModelPredictiveControl.h.

constexpr double lipm_walking::ModelPredictiveControl::SAMPLING_PERIOD = 0.1

static

Duration of each sampling step in [s].

Definition at line 56 of file ModelPredictiveControl.h.

constexpr unsigned lipm_walking::ModelPredictiveControl::STATE_SIZE = 6

static

State is the 6D stacked vector of CoM positions, velocities and accelerations.

Definition at line 59 of file ModelPredictiveControl.h.

Eigen::Vector2d lipm_walking::ModelPredictiveControl::velWeights = {10., 10.}

Weights of CoM velocity tracking cost.

Definition at line 249 of file ModelPredictiveControl.h.

double lipm_walking::ModelPredictiveControl::zmpWeight = 1000.

Weight of reference ZMP tracking cost.

Definition at line 251 of file ModelPredictiveControl.h.

Public Member Functions

Public Attributes

Static Public Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation