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Display reference path in figure

Since R2020b



show(refPath) displays the reference path and its lateral states in the current figure.

show(refPath,'Parent',parentAx) displays the reference path on the specified axes. parentAx is specified as an Axes handle.

ax = show(___) displays the reference path using any of the previous input combinations and returns the axes handle on which the reference path is plotted.


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Generate alternative trajectories for a reference path using Frenet coordinates. Specify different initial and terminal states for your trajectories. Tune your states based on the generated trajectories.

Generate a reference path from a set of waypoints. Create a trajectoryGeneratorFrenet object from the reference path.

waypoints = [0 0; ...
	50 20; ...
	100 0; ...
	150 10];
refPath = referencePathFrenet(waypoints);
connector = trajectoryGeneratorFrenet(refPath);

Generate a five-second trajectory between the path origin and a point 30 m down the path as Frenet states.

initState = [0 0 0 0 0 0];  % [S ds ddS L dL ddL]
termState = [30 0 0 0 0 0]; % [S ds ddS L dL ddL]
[~,trajGlobal] = connect(connector,initState,termState,5);

Display the trajectory in global coordinates.

hold on
axis equal
legend(["Waypoints","Reference Path","Trajectory to 30m"])

Create a matrix of terminal states with lateral deviations between –3 m and 3 m. Generate trajectories that cover the same arc length in 10 seconds, but deviate laterally from the reference path. Display the new alternative paths.

termStateDeviated = termState + ([-3:3]' * [0 0 0 1 0 0]);
[~,trajGlobal] = connect(connector,initState,termStateDeviated,10);

hold on
axis equal
for i = 1:length(trajGlobal)
legend(["Waypoints","Reference Path","Alternative Trajectories"])
hold off

Specify a new terminal state to generate a new trajectory. This trajectory is not desirable because it requires reverse motion to achieve a longitudinal velocity of 10 m/s.

newTermState = [5 10 0 5 0 0];
[~,newTrajGlobal] = connect(connector,initState,newTermState,3);

hold on
axis equal
legend(["Waypoint","Reference Path","New Trajectory"])
hold off

Relax the restriction on the longitudinal state by specifying an arc length of NaN. Generate and display the trajectory again. The new position shows a good alternative trajectory that deviates off the reference path.

relaxedTermState = [NaN 10 0 5 0 0];
[~,trajGlobalRelaxed] = connect(connector,initState,relaxedTermState,3);

hold on
axis equal
hold off

Input Arguments

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Reference path, specified as a referencePathFrenet object.

Output Arguments

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Axes on which the reference path is plotted, returned as an Axes handle.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced in R2020b