Nodes that are associated to either swing or stance phases. More...

#include <nodes_variables_phase_based.h>

Inheritance diagram for towr::NodesVariablesPhaseBased:

Classes
struct	PolyInfo
	Holds semantic information each polynomial in spline. More...
Public Member Functions
virtual VecDurations	ConvertPhaseToPolyDurations (const VecDurations &phase_durations) const
	Converts durations of swing and stance phases to polynomial durations.
virtual double	GetDerivativeOfPolyDurationWrtPhaseDuration (int polynomial_id) const
	How a change in the phase duration affects the polynomial duration.
NodeIds	GetIndicesOfNonConstantNodes () const
	The indices of those nodes that don't belong to a constant phase.
int	GetNodeIDAtStartOfPhase (int phase) const
virtual int	GetNumberOfPrevPolynomialsInPhase (int polynomial_id) const
	How many polynomials in the current phase come before.
int	GetPhase (int node_id) const
Eigen::Vector3d	GetValueAtStartOfPhase (int phase) const
virtual bool	IsConstantNode (int node_id) const
	node is constant if either left or right polynomial belongs to a constant phase.
virtual bool	IsInConstantPhase (int polynomial_id) const
	Is the polynomial constant, so not changing the value.
	NodesVariablesPhaseBased (int phase_count, bool first_phase_constant, const std::string &var_name, int n_polys_in_changing_phase)
	Constructs a variable set of node variables.
virtual	~NodesVariablesPhaseBased ()
Protected Member Functions
std::vector< NodeValueInfo >	GetNodeValuesInfo (int idx) const override
	Node values affected by one specific optimization variable.
void	SetNumberOfVariables (int n_variables)
Protected Attributes
OptIndexMap	index_to_node_value_info_
	Assign optimization variables to the correct node values.
Private Member Functions
std::vector< int >	GetAdjacentPolyIds (int node_id) const
	IDs of the polynomial to the left and right of node_id.
int	GetPolyIDAtStartOfPhase (int phase) const
	ID of the first polynomial of a phase.
Private Attributes
std::vector< PolyInfo >	polynomial_info_
	semantic information associated with each polynomial

Detailed Description

Nodes that are associated to either swing or stance phases.

**Not all node values must be optimized over**. We can for example fix node derivatives to 0.0 and also use the same optimization variable to fill to node positions. If the spline represents the position of an end-effector, this means that no matter which values the the solver chooses, the foot will never move during the stance phase. This is done in NodesVariablesEEMotion. A force spline is parameterized in the reverse way, with multiple nodes during stance phase. This is implemented in NodesVariablesEEForce.

#### Motion (dim: x) and force (dim: z) spline for one foot

A high-level explanation of this concept can be found here: https://youtu.be/KhWuLvb934g?t=1004

Definition at line 59 of file nodes_variables_phase_based.h.

Constructor & Destructor Documentation

towr::NodesVariablesPhaseBased::NodesVariablesPhaseBased	(	int	phase_count,
		bool	first_phase_constant,
		const std::string &	var_name,
		int	n_polys_in_changing_phase
	)

Constructs a variable set of node variables.

Parameters:

phase_count	The number of phases (swing, stance) to represent.
first_phase_constant	Whether first node belongs to a constant phase.
var_name	The name given to this set of optimization variables.
n_polys_in_changing_phase	How many polynomials should be used to paramerize each non-constant phase.

Definition at line 60 of file nodes_variables_phase_based.cc.

virtual towr::NodesVariablesPhaseBased::~NodesVariablesPhaseBased ( ) [virtual]

Member Function Documentation

NodesVariablesPhaseBased::VecDurations towr::NodesVariablesPhaseBased::ConvertPhaseToPolyDurations ( const VecDurations & phase_durations ) const [virtual]

Converts durations of swing and stance phases to polynomial durations.

Parameters:

phase_durations The durations of alternating swing and stance phases.

Returns:: The durations of each polynomial, where multiple polynomials can be used to represent one phase.

Definition at line 74 of file nodes_variables_phase_based.cc.

std::vector< int > towr::NodesVariablesPhaseBased::GetAdjacentPolyIds ( int node_id ) const [private]

IDs of the polynomial to the left and right of node_id.

Definition at line 164 of file nodes_variables_phase_based.cc.

double towr::NodesVariablesPhaseBased::GetDerivativeOfPolyDurationWrtPhaseDuration ( int polynomial_id ) const [virtual]

How a change in the phase duration affects the polynomial duration.

Parameters:

polynomial_id The ID of the polynomial within the spline.

If a phase is represented by multiple (3) equally timed polynomials, then T_poly = 1/3 * T_phase. The derivative of T_poly is then 1/3.

Definition at line 87 of file nodes_variables_phase_based.cc.

NodesVariablesPhaseBased::NodeIds towr::NodesVariablesPhaseBased::GetIndicesOfNonConstantNodes ( ) const

The indices of those nodes that don't belong to a constant phase.

For forces nodes these are the stance phases (can produce force), and for feet these are the swing phases (can move end-effector).

Definition at line 120 of file nodes_variables_phase_based.cc.

int towr::NodesVariablesPhaseBased::GetNodeIDAtStartOfPhase ( int phase ) const

Returns:: the ID of the first node in the phase.

Definition at line 157 of file nodes_variables_phase_based.cc.

std::vector<NodeValueInfo> towr::NodesVariablesPhaseBased::GetNodeValuesInfo ( int opt_idx ) const [inline, override, protected, virtual]

Node values affected by one specific optimization variable.

Parameters:

opt_idx The index (=row) of the optimization variable.

Returns:: All node values affected by this optimization variable.

This function determines which node values are optimized over, and which nodes values are set by the same optimization variable.

Reverse of GetOptIndex().

Implements towr::NodesVariables.

Definition at line 168 of file nodes_variables_phase_based.h.

int towr::NodesVariablesPhaseBased::GetNumberOfPrevPolynomialsInPhase ( int polynomial_id ) const [virtual]

How many polynomials in the current phase come before.

Parameters:

polynomial_id The ID of the polynomial within the spline.

If a phase is represented by multiple (3) polynomials, and the current polynomial corresponds to the third one in the phase, then 2 polynomials come before it.

Definition at line 94 of file nodes_variables_phase_based.cc.

int towr::NodesVariablesPhaseBased::GetPhase ( int node_id ) const

Returns:: The phase ID belonging to node with node_id.

Only makes sense if left and right polynomial belong to same phase.

Definition at line 132 of file nodes_variables_phase_based.cc.

int towr::NodesVariablesPhaseBased::GetPolyIDAtStartOfPhase ( int phase ) const [private]

ID of the first polynomial of a phase.

Definition at line 141 of file nodes_variables_phase_based.cc.

Eigen::Vector3d towr::NodesVariablesPhaseBased::GetValueAtStartOfPhase ( int phase ) const

Returns:: the value of the first node of the phase.

Definition at line 150 of file nodes_variables_phase_based.cc.

bool towr::NodesVariablesPhaseBased::IsConstantNode ( int node_id ) const [virtual]

node is constant if either left or right polynomial belongs to a constant phase.

Definition at line 100 of file nodes_variables_phase_based.cc.

bool towr::NodesVariablesPhaseBased::IsInConstantPhase ( int polynomial_id ) const [virtual]

Is the polynomial constant, so not changing the value.

Parameters:

polynomial_id The ID of the polynomial within the spline.

Definition at line 114 of file nodes_variables_phase_based.cc.

void towr::NodesVariablesPhaseBased::SetNumberOfVariables ( int n_variables ) [protected]

Definition at line 191 of file nodes_variables_phase_based.cc.

Member Data Documentation

OptIndexMap towr::NodesVariablesPhaseBased::index_to_node_value_info_ [protected]

Assign optimization variables to the correct node values.

This map is the main element that implements _Phase-based End-effector Parameterization_ and is generated by the derived Motion and Force classes.

Definition at line 167 of file nodes_variables_phase_based.h.

std::vector<PolyInfo> towr::NodesVariablesPhaseBased::polynomial_info_ [private]

semantic information associated with each polynomial

Definition at line 176 of file nodes_variables_phase_based.h.

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

Classes

Public Member Functions

Protected Member Functions

Protected Attributes

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation