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clothoidLaneBoundary

Clothoid-shaped lane boundary model

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Description

A clothoidLaneBoundary object contains information about a clothoid-shaped lane boundary model. A clothoid is a type of curve whose rate of change of curvature varies linearly with distance.

Creation

Syntax

bdry = clothoidLaneBoundary
bdry = clothoidLaneBoundary(Name,Value)

Description

bdry = clothoidLaneBoundary creates a clothoid lane boundary model, bdry with default property values.

bdry = clothoidLaneBoundary(Name,Value) sets properties using one or more name-value pairs. For example, clothoidLaneBoundary('BoundaryType','Solid') creates a clothoid lane boundary model with solid lane boundaries. Enclose each property name in quotes.

example

Properties

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Lane boundary curvature, specified as a real scalar. This property represents the rate of change of lane boundary direction with respect to distance. Units are in degrees per meter.

Example: -1.0

Data Types: single | double

Derivative of lane boundary curvature, specified as a real scalar. This property represents the rate of change of lane curvature with respect to distance. Units are in degrees per meter squared.

Example: -0.01

Data Types: single | double

Length of the lane boundary along the road, specified as a nonnegative real scalar. Units are in meters.

Example: 25

Data Types: single | double

Initial lane boundary heading, specified as a real scalar. The heading angle of the lane boundary is relative to the heading of the ego vehicle. Units are in degrees.

Example: 10

Data Types: single | double

Lateral offset of the ego vehicle position from the lane boundary, specified as a real scalar. An offset to a lane boundary to the left of the ego vehicle is positive. An offset to the right of the ego vehicle is negative. Units are in meters. In this image, the ego vehicle is offset 1.5 meters from the left lane and 2.1 meters from the right lane.

Ego vehicle in a driving lane

Example: -1.2

Data Types: single | double

Type of lane boundary marking, specified as one of these values.

'Unmarked' 'Solid''Dashed''DoubleSolid''DoubleDashed''SolidDashed''DashedSolid'

No lane marking

Solid line

Dashed line

Two solid lines

Two dashed lines

Solid line on left, dashed line on right

Dashed line on left, solid line on right

Sample of an unmarked lane

Sample of a solid lane marking

Sample of a dashed lane marking

Sample of a double-solid lane marking

Sample of a double-dashed lane marking

Sample of a solid-dashed lane marking

Sample of a dashed-solid lane marking

Visibility of lane marking, specified as a real scalar in the range [0, 1]. A value of 0 corresponds to a marking that is not visible. A value of 1 corresponds to a marking that is completely visible. For a double lane marking, the same strength is used for both lines.

Example: 0.9

Data Types: single | double

Extent of the lane boundary marking along the X-axis, specified as a real-valued vector of the form [Xmin Xmax]. Units are in meters. The X-axis runs vertically and is positive in the forward direction of the ego vehicle.

Example: [0 100]

Data Types: single | double

Width of lane boundary marking, specified as a nonnegative real scalar. For a double lane marking, this value applies to the width of each lane marking and to the distance between those markings. Units are in meters.

Example: 0.15

Data Types: single | double

Object Functions

computeBoundaryModelCompute lane boundary points from clothoid lane boundary model

Examples

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Open Live Script

Create clothoid curves to represent left and right lane boundaries. Then, plot the curves.

Create the left boundary.

lb = clothoidLaneBoundary('BoundaryType','Solid', ...
'Strength',1,'Width',0.2,'CurveLength',40, ...
'Curvature',-0.8,'LateralOffset',2,'HeadingAngle',10);

Create the right boundary with almost identical properties.

rb = lb;
rb.LateralOffset = -2;

Create a bird's-eye plot. Then, create the lane boundary plotters and plot the boundaries.

bep = birdsEyePlot('XLimits',[0 50],'YLimits',[-10 10]);
lbPlotter = laneBoundaryPlotter(bep,'DisplayName','Left-lane boundary','Color','r');
rbPlotter = laneBoundaryPlotter(bep,'DisplayName','Right-lane boundary','Color','g');
plotLaneBoundary(lbPlotter,lb)
plotLaneBoundary(rbPlotter,rb);

Figure contains an axes object. The axes object with xlabel X (m), ylabel Y (m) contains 2 objects of type line. These objects represent Left-lane boundary, Right-lane boundary.

grid
hold on

Figure contains an axes object. The axes object is empty.

Plot the coordinates of selected points along the boundaries.

x = 0:5:50;
yl = computeBoundaryModel(lb,x);
yr = computeBoundaryModel(rb,x);
plot(x,yl,'ro')
plot(x,yr,'go')
hold off

Figure contains an axes object. The axes object contains 2 objects of type line. One or more of the lines displays its values using only markers

Version History

Introduced in R2018a

See Also

Objects

Functions