Detailed Description

A Lane represents a lane of travel in a road network.

A Lane defines a curvilinear coordinate system covering the road surface, with a longitudinal 's' coordinate that expresses the arc-length along a central reference curve. The reference curve nominally represents an ideal travel trajectory along the Lane.

Lanes are grouped by Segment. All Lanes belonging to a Segment represent the same road surface, but with different coordinate parameterizations (e.g., each Lane has its own reference curve).

#include <include/maliput/api/lane.h>

Inheritance diagram for Lane:

[legend]

Public Member Functions
virtual	~Lane ()=default

LaneId	id () const
	Returns the persistent identifier. More...

const Segment *	segment () const
	Returns the Segment to which this Lane belongs. More...

int	index () const
	Returns the index of this Lane within the Segment which owns it. More...

const Lane *	to_left () const
	Returns a pointer to the adjacent Lane to the left of this Lane. More...

const Lane *	to_right () const
	Returns a pointer to the adjacent Lane to the right of this Lane. More...

double	length () const
	Returns the arc-length of the Lane along its reference curve. More...

RBounds	lane_bounds (double s) const
	Returns the nominal lateral (r) bounds for the lane as a function of s. More...

RBounds	segment_bounds (double s) const
	Returns the lateral segment (r) bounds of the lane as a function of s. More...

HBounds	elevation_bounds (double s, double r) const
	Returns the elevation (`h`) bounds of the lane as a function of `(s, r)`. More...

LaneType	type () const
	Returns the type of Lane, such as `driving`, `biking`, etc. More...

InertialPosition	ToInertialPosition (const LanePosition &lane_pos) const
	Returns the `maliput::api::InertialPosition` corresponding to the given `maliput::api::LanePosition`. More...

double	GetCurvature (const LanePosition &lane_pos) const
	Returns the signed Euclidean curvature at the given `maliput::api::LanePosition`. More...

LanePositionResult	ToLanePosition (const InertialPosition &inertial_pos) const
	Determines the LanePosition corresponding to InertialPosition `inertial_pos`. More...

LanePositionResult	ToSegmentPosition (const InertialPosition &inertial_pos) const
	Determines the LanePosition corresponding to InertialPosition `inertial_pos`. More...

Rotation	GetOrientation (const LanePosition &lane_pos) const
	Returns the rotation which expresses the orientation of the `Lane`-frame basis at `lane_pos` with respect to the `Inertial`-frame basis. More...

LanePosition	EvalMotionDerivatives (const LanePosition &position, const IsoLaneVelocity &velocity) const
	Computes derivatives of LanePosition given a velocity vector `velocity`. More...

const BranchPoint *	GetBranchPoint (const LaneEnd::Which which_end) const
	Returns the lane's BranchPoint for the end specified by `which_end`. More...

const LaneEndSet *	GetConfluentBranches (const LaneEnd::Which which_end) const
	Returns the set of LaneEnd's which connect with this lane on the same side of the BranchPoint at `which_end`. More...

const LaneEndSet *	GetOngoingBranches (const LaneEnd::Which which_end) const
	Returns the set of LaneEnd's which continue onward from this lane at the BranchPoint at `which_end`. More...

std::optional< LaneEnd >	GetDefaultBranch (const LaneEnd::Which which_end) const
	Returns the default ongoing LaneEnd connected at `which_end`, or std::nullopt if no default branch has been established at `which_end`. More...

const LaneBoundary *	left_boundary () const
	Returns the LaneBoundary at the left edge of this Lane. More...

const LaneBoundary *	right_boundary () const
	Returns the LaneBoundary at the right edge of this Lane. More...

bool	Contains (const LanePosition &lane_position) const
	Returns if this lane contains `lane_position`. More...

std::optional< bool >	is_intersection () const
	Returns whether this lane is part of an intersection. More...

Protected Member Functions
	Lane ()=default

Constructor & Destructor Documentation

◆ ~Lane()

virtual ~Lane ( )

virtualdefault

Reimplemented in Lane.

◆ Lane()

Lane ( )

protecteddefault

Member Function Documentation

◆ Contains()

bool Contains ( const LanePosition & lane_position ) const

Returns if this lane contains lane_position.

◆ elevation_bounds()

HBounds elevation_bounds	(	double	s,
		double	r
	)		const

Returns the elevation (h) bounds of the lane as a function of (s, r).

These are the elevation bounds for a position that is considered to be within the Lane's volume modeled by the RoadGeometry.

s is within [0, length()] of this Lane and r is within lane_bounds(s).

◆ EvalMotionDerivatives()

LanePosition EvalMotionDerivatives	(	const LanePosition &	position,
		const IsoLaneVelocity &	velocity
	)		const

Computes derivatives of LanePosition given a velocity vector velocity.

velocity is a isometric velocity vector oriented in the Lane-frame at position.

Returns: Lane-frame derivatives packed into a LanePosition struct.

◆ GetBranchPoint()

const BranchPoint * GetBranchPoint ( const LaneEnd::Which which_end ) const

Returns the lane's BranchPoint for the end specified by which_end.

◆ GetConfluentBranches()

const LaneEndSet * GetConfluentBranches ( const LaneEnd::Which which_end ) const

Returns the set of LaneEnd's which connect with this lane on the same side of the BranchPoint at which_end.

At a minimum, this set will include this Lane.

◆ GetCurvature()

double GetCurvature ( const LanePosition & lane_pos ) const

Returns the signed Euclidean curvature at the given maliput::api::LanePosition.

The Euclidean curvature magnitude is defined as the reciprocal of the radius of the osculating circle at a given point on the curve: \( |\kappa| = 1/R \).

The sign convention follows the right-hand rule with respect to the lane's h-axis (vertical/normal direction):

Positive curvature: The path curves to the left (toward +r direction), i.e., counter-clockwise when viewed from above.
Negative curvature: The path curves to the right (toward -r direction), i.e., clockwise when viewed from above.

Parameters

lane_pos A maliput::api::LanePosition. The s component must be in domain [0, Lane::length()]. The r and h components are used to determine the curvature at the corresponding offset from the centerline.

Returns: The signed Euclidean curvature (1/m) at the given position.

◆ GetDefaultBranch()

std::optional< LaneEnd > GetDefaultBranch ( const LaneEnd::Which which_end ) const

Returns the default ongoing LaneEnd connected at which_end, or std::nullopt if no default branch has been established at which_end.

◆ GetOngoingBranches()

const LaneEndSet * GetOngoingBranches ( const LaneEnd::Which which_end ) const

Returns the set of LaneEnd's which continue onward from this lane at the BranchPoint at which_end.

◆ GetOrientation()

Rotation GetOrientation ( const LanePosition & lane_pos ) const

Returns the rotation which expresses the orientation of the Lane-frame basis at lane_pos with respect to the Inertial-frame basis.

◆ id()

LaneId id ( ) const

Returns the persistent identifier.

◆ index()

int index ( ) const

Returns the index of this Lane within the Segment which owns it.

◆ is_intersection()

std::optional< bool > is_intersection ( ) const

Returns whether this lane is part of an intersection.

Returns: true when lane belongs to an intersection.; false when lane is known not to belong to an intersection.; std::nullopt when intersection information is unavailable.

◆ lane_bounds()

RBounds lane_bounds ( double s ) const

Returns the nominal lateral (r) bounds for the lane as a function of s.

These are the lateral bounds for a position that is considered to be "staying in the lane".

See also: segment_bounds(double s) that defines the whole surface.

◆ left_boundary()

const LaneBoundary * left_boundary ( ) const

Returns the LaneBoundary at the left edge of this Lane.

The left boundary is in the +r direction (increasing r coordinate). This is equivalent to segment()->boundary(index() + 1).

Returns: The left boundary, or nullptr if boundary information is not available for the parent Segment.

◆ length()

double length ( ) const

Returns the arc-length of the Lane along its reference curve.

The value of length() is also the maximum s-coordinate for this Lane; i.e., the domain of s is [0, length()].

◆ right_boundary()

const LaneBoundary * right_boundary ( ) const

Returns the LaneBoundary at the right edge of this Lane.

The right boundary is in the -r direction (decreasing r coordinate). This is equivalent to segment()->boundary(index()).

Returns: The right boundary, or nullptr if boundary information is not available for the parent Segment.

◆ segment()

const Segment * segment ( ) const

Returns the Segment to which this Lane belongs.

◆ segment_bounds()

RBounds segment_bounds ( double s ) const

Returns the lateral segment (r) bounds of the lane as a function of s.

These are the lateral bounds for a position that is considered to be "on segment", reflecting the physical extent of the surface of the lane's segment.

See also: lane_bounds(double s) that defines what's considered to be "staying in the lane".

◆ to_left()

const Lane * to_left ( ) const

Returns a pointer to the adjacent Lane to the left of this Lane.

Left is considered the +r direction with regards to the (s,r,h) frame, e.g., "to the left along the +s direction".

Returns: nullptr iff parent Segment has no Lane to the left.

◆ to_right()

const Lane * to_right ( ) const

Returns a pointer to the adjacent Lane to the right of this Lane.

Right is considered the -r direction with regards to the (s,r,h) frame, e.g., "to the right along the +s direction".

Returns: nullptr iff parent Segment has no Lane to the right.

◆ ToInertialPosition()

InertialPosition ToInertialPosition ( const LanePosition & lane_pos ) const

Returns the maliput::api::InertialPosition corresponding to the given maliput::api::LanePosition.

Note there is no constraint for the r coordinate, as it can be outside the lane boundaries. In that scenario, the resultant inertial position represents a point in the s-r plane at the given s and h coordinates. It's on the user side to verify, if needed, that the lane position is within lane boundaries.

Precondition: The s component of lane_pos must be in domain [0, Lane::length()].

Parameters

lane_pos A maliput::api::LanePosition. Although the s component must be in domain [0, Lane::length()], the r component can be outside the lane's RBounds, so that the position is on the s-r plane.

Returns: An InertialPosition for the given lane_pos.

◆ ToLanePosition()

LanePositionResult ToLanePosition ( const InertialPosition & inertial_pos ) const

Determines the LanePosition corresponding to InertialPosition inertial_pos.

The LanePosition is expected to be contained within the lane's boundaries.

See also: ToSegmentPosition method.

This method guarantees that its result satisfies the condition that ToInertialPosition(result.lane_position) is within linear_tolerance() of result.nearest_position.

◆ ToSegmentPosition()

LanePositionResult ToSegmentPosition ( const InertialPosition & inertial_pos ) const