plan

Plan vehicle path using RRT* path planner

Syntax

refPath = plan(planner,startPose,goalPose)

[refPath,tree] = plan(planner,startPose,goalPose)

Description

refPath = plan(planner,startPose,goalPose) plans a vehicle path from startPose to goalPose using the input pathPlannerRRT object. This object configures an optimal rapidly exploring random tree (RRT*) path planner.

[refPath,tree] = plan(planner,startPose,goalPose) also returns the exploration tree, tree.

Examples

Plan Path to Parking Spot

Plan a vehicle path to a parking spot by using the RRT* algorithm.

Load a costmap of a parking lot. Plot the costmap to see the parking lot and inflated areas for the vehicle to avoid.

data = load('parkingLotCostmapReducedInflation.mat');
costmap = data.parkingLotCostmapReducedInflation;
plot(costmap)

Define start and goal poses for the path planner as [x, y, Θ] vectors. World units for the (x,y) locations are in meters. World units for the Θ orientation values are in degrees.

startPose = [11, 10, 0]; % [meters, meters, degrees]
goalPose  = [31.5, 17, 90];

Create an RRT* path planner to plan a path from the start pose to the goal pose.

planner = pathPlannerRRT(costmap);
refPath = plan(planner,startPose,goalPose);

Plot the planned path.

plot(planner)

Input Arguments

planner — RRT* path planner

pathPlannerRRT object

RRT* path planner, specified as a pathPlannerRRT object.

startPose — Initial pose of vehicle

[x, y, Θ] vector

Initial pose of the vehicle, specified as an [x, y, Θ] vector. x and y are in world units, such as meters. Θ is in degrees.

goalPose — Goal pose of vehicle

[x, y, Θ] vector

Goal pose of the vehicle, specified as an [x, y, Θ] vector. x and y are in world units, such as meters. Θ is in degrees.

The vehicle achieves its goal pose when the last pose in the path is within the GoalTolerance property of planner.

Output Arguments

refPath — Planned vehicle path

driving.Path object

Planned vehicle path, returned as a driving.Path object containing reference poses along the planned path. If planning was unsuccessful, the path has no poses. To check if the path is still valid due to costmap updates, use the checkPathValidity function.

tree — Exploration tree

digraph object

Exploration tree, returned as a digraph object. Nodes within tree represent explored vehicle poses. Edges within tree represent the distance between connected nodes.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• The optional tree output argument, a digraph object, is not supported.

Version History

Introduced in R2018a