show

Visualize path segment

Syntax

show(pathSeg)

show(pathSeg,Name,Value)

Description

show(pathSeg) plots the path segment with start and goal positions and their headings.

show(pathSeg,Name,Value) also specifies Name,Value pairs to control display settings.

Examples

Connect Poses Using Dubins Connection Path

Create a dubinsConnection object.

dubConnObj = dubinsConnection;

Define start and goal poses as [x y theta] vectors.

startPose = [0 0 0];
goalPose = [1 1 pi];

Calculate a valid path segment to connect the poses.

[pathSegObj, pathCosts] = connect(dubConnObj,startPose,goalPose);

Show the generated path.

show(pathSegObj{1})

Modify Connection Types for Reeds-Shepp Path

Create a reedsSheppConnection object.

reedsConnObj = reedsSheppConnection;

Define start and goal poses as [x y theta] vectors.

startPose = [0 0 0];
goalPose = [1 1 pi];

Calculate a valid path segment to connect the poses.

[pathSegObj,pathCosts] = connect(reedsConnObj,startPose,goalPose);

Show the generated path. Notice the direction of the turns.

show(pathSegObj{1})

pathSegObj{1}.MotionTypes

ans = 1×5 cell
    {'L'}    {'R'}    {'L'}    {'N'}    {'N'}

pathSegObj{1}.MotionDirections

ans = 1×5

     1    -1     1     1     1

Disable this specific motion sequence in a new connection object. Reduce the MinTurningRadius if the robot is more maneuverable. Increase the reverse cost to reduce the likelihood of reverse directions being used. Connect the poses again to get a different path.

reedsConnObj = reedsSheppConnection('DisabledPathTypes',{'LpRnLp'});
reedsConnObj.MinTurningRadius = 0.5;
reedsConnObj.ReverseCost = 5;

[pathSegObj,pathCosts] = connect(reedsConnObj,startPose,goalPose);
pathSegObj{1}.MotionTypes

ans = 1×5 cell
    {'L'}    {'S'}    {'L'}    {'N'}    {'N'}

show(pathSegObj{1})
xlim([0 1.5])
ylim([0 1.5])

Interpolate Poses for Dubins Path

Create a dubinsConnection object.

dubConnObj = dubinsConnection;

Define start and goal poses as [x y theta] vectors.

startPose = [0 0 0];
goalPose = [1 1 pi];

Calculate a valid path segment to connect the poses.

[pathSegObj,pathCosts] = connect(dubConnObj,startPose,goalPose);

Show the generated path.

show(pathSegObj{1})

Interpolate poses along the path. Get a pose every 0.2 meters, including the transitions between turns.

length = pathSegObj{1}.Length;
poses = interpolate(pathSegObj{1},0:0.2:length)

poses = 32×3

         0         0         0
    0.1987   -0.0199    6.0832
    0.3894   -0.0789    5.8832
    0.5646   -0.1747    5.6832
    0.7174   -0.3033    5.4832
    0.8309   -0.4436    5.3024
    0.8418   -0.4595    5.3216
    0.9718   -0.6110    5.5216
    1.1293   -0.7337    5.7216
    1.3081   -0.8226    5.9216
    1.5010   -0.8743    6.1216
    1.7003   -0.8866    0.0384
    1.8980   -0.8590    0.2384
    2.0864   -0.7927    0.4384
    2.2578   -0.6904    0.6384
      ⋮

Use the quiver function to plot these poses.

quiver(poses(:,1),poses(:,2),cos(poses(:,3)),sin(poses(:,3)),0.5)

Input Arguments

pathSeg — Path segment

dubinsPathSegment object | reedsSheppPathSegment object

Path segment, specified as a dubinsPathSegment or reedsSheppPathSegment object.

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: 'Headings',{'transitions'}

Parent — Axes to plot path onto

Axes handle

Axes to plot path onto, specified as an Axes handle.

Headings — Heading angles to display

cell array of character vector or string scalars

Heading angles to display, specified as a cell array of character vector or string scalars. Options are any combination of 'start','goal', and 'transitions'. To disable all heading displays, specify {''}.

Positions — Positions to display

'both' (default) | 'start' | 'goal' | 'none'

Positions to display, specified as 'both', 'start', 'goal', or 'none'. The start position is marked with green, and the goal position is marked with red.

HeadingLength — Length of heading

positive numeric scalar

Length of heading, specified as positive numeric scalar. By default the value is calculated according to the x- and y-axis limits of the plot.

Data Types: double

Version History

Introduced in R2019b