rrt_planner

The rrt_planner ROS package provides a framework to implement sampling based motion planners (RRT and its variants) as global planner plugin for move_base, a ROS framework. Please refer to http://wiki.ros.org/move_base, for a detailed description of the move_base framework.

Demo

Install Dependencies and Build

cd ~/catkin_ws/src
git clone https://github.com/irob-labs-ist/rrt_planner.git
cd .. && rosdep install --from-paths src --ignore-src -r -y
catkin_make
source devel/setup.bash

Usage

Within the move_base node in your launch file, set the base_global_planner parameter to rrt_planner/RRTPlannerROS and load the required parameters.

<param name="base_global_planner" value="rrt_planner/RRTPlannerROS"/>
<rosparam file="$(find rrt_planner)/config/rrt_planner.yaml" command="load" />

After launching the system, when you set a move_base/goal using RViz's 2D Nav Goal or with an action client, the RRTPlannerROS will be called. The global path will be published as a topic for visualization in RViz. Add a Path display and subscribe to ~/move_base/RRTPlannerROS/global_plan.

Examples

An example launch file for using RRTPlannerROS is located in rrt_planner/launch. An example RViz config file for using RRTPlannerROS with the TurtleBot3 Simulation is located in rrt_planner/rviz.

Troubleshooting

If you find that the RRT planner continues to produce plans even after a solution has been found, try setting the /move_base/planner_frequency to 0. Zero is normally what the default value is (see planner_frequency on the move_base Wiki), but that's not what the value is in the turtlebot examples. If you're running the turtlebot examples, you can change the parameter in turtlebot3_navigation/param/move_base_params.yaml.

If you see that the RRT planner repeatedly fails to find a solution, you may want to play around with the parameters in the rrt_planner.yaml configuration file.

ROS API

Published Topics

~/move_base/RRTPlannerROS/global_plan (nav_msgs/Path)

• The global path constructed by the planner. Used for visualization purposes.

Subscribed Topics

None.

Parameters

~/move_base/RRTPlannerROS/goal_tolerance (double, default: 0.20)

• Goal tolerance (in meters) to be achieved by the global planner.

~/move_base/RRTPlannerROS/rrt/step (double, default: 0.20)

• Distance (in meters) to extend tree per iteration.

~/move_base/RRTPlannerROS/rrt/min_num_nodes (int, default: 200)

• Minumum number of iterations to attempt to find a plan.

~/move_base/RRTPlannerROS/rrt/max_num_nodes (int, default: 5,000)

• Maximum number of iterations to attempt to find a plan.

Services

None.