ITS Path Planner Plugin Customization

The ROS 2 navigation bring-up application is started using the TurtleBot* 3 Gazebo* simulation, and it receives as input parameter its_nav2_params.yaml.

Check the code snippet from 01_docker_sdk_env/docker_compose/05_tutorials/its_path_planner.tutorial.yml:

export TURTLEBOT3_MODEL=waffle
export GAZEBO_MODEL_PATH=$GAZEBO_MODEL_PATH:/home/eiforamr/ros2_ws/install/turtlebot3_gazebo/share/turtlebot3_gazebo/models/
ros2 launch nav2_bringup tb3_simulation_launch.py params_file:=${CONTAINER_BASE_PATH}/01_docker_sdk_env/docker_compose/05_tutorials/param/its_nav2_params.yaml

To use the ITS path planner plugin, the following parameters are added in its_nav2_params.yaml:

planner_server:
  ros__parameters:
    expected_planner_frequency: 0.01
    use_sim_time: True
    planner_plugins: ["GridBased"]
    GridBased:
      plugin: "its_planner/ITSPlanner"
      interpolation_resolution: 0.05
      catmull_spline: False
      smoothing_window: 15
      buffer_size: 10
      build_road_map_once: True
      min_samples: 250
      roadmap: "PROBABLISTIC"
      w: 32
      h: 32
      n: 2

ITS Path Planner Plugin Parameters

catmull_spline:

If true, the generated path from the ITS is interpolated with the catmull spline method; otherwise, a smoothing filter is used to smooth the path.

smoothing_window:

The window size for the smoothing filter (The unit is the grid size.)

buffer_size:

During roadmap generation, the samples are generated away from obstacles. The buffer size dictates how far away from obstacles the roadmap samples should be.

build_road_map_once:

If true, the roadmap is loaded from the saved file; otherwise, a new roadmap is generated.

min_samples:

The minimum number of samples required to generate the roadmap

roadmap:

Either PROBABILISTIC or DETERMINISTIC

w:

The width of the window for intelligent sampling

h:

The height of the window for intelligent sampling

n:

The minimum number of samples that is required in an area defined by w and h

You can modify these values by editing the file below, at lines 251-267:

01_docker_sdk_env/docker_compose/05_tutorials/param/its_nav2_params.yaml