global-costmap-config

Set global_frame to map, robot_base_frame to base_link, resolution to 0.05, and define either robot_radius or a polygon footprint. Add static, obstacle, and inflation layers as plugins, then tune inflation_radius and cost_scaling_factor.

Use robot_radius for circular robots since it is simpler and faster for collision checking. Use a polygon footprint for non-circular robots, but never set both because footprint takes precedence and causes confusion.

Include obstacle or voxel layers when using long-range lidar over 5 meters or when running in SLAM mode without a static map. Skip them for short-range sensors under 3 meters since the local costmap handles dynamic obstacles.

An empty costmap usually means the static map is not being published or TF is broken. Verify the map with ros2 topic echo /map --once and confirm the sensor frame connects to the map frame through the TF tree.

track_unknown_space controls whether unknown cells in the static map stay unknown in the costmap. When true, the planner avoids unmapped areas; when false, unknown space is treated as free and the planner may route through it.