REP 105

The ROS convention defining the map, odom, and base_link coordinate frames for mobile robots.

REP 105 is a ROS Enhancement Proposal — a community specification — that fixes the names and meanings of the coordinate frames commonly used by mobile robots. base_link is fixed to the robot's own body; odom is the odometry frame, in which the robot's pose is continuous and smooth but slowly drifts over time; map is the global map frame, where the pose doesn't drift but can jump when corrected by localization. The three are chained into a TF tree as map → odom → base_link: the localization module is responsible only for publishing map → odom, while odometry publishes odom → base_link. This shared convention is what lets independently written navigation, SLAM, and localization packages plug together — Nav2 and others all follow it.

ExampleA robot publishes odom → base_link from wheel odometry, while an AMCL localization node publishes map → odom based on laser-scan matching; combined, the two give the robot's position on the map.

Also called

REP 105: Coordinate Frames for Mobile Platforms, map–odom–base_link

Related

TF / tf2 Transform Tree · Coordinate Frame · ROS 2 Navigation Stack (Nav2) · Wheel Odometry · Adaptive Monte Carlo Localization · Right-Handed Frame & Axis Conventions

Sources

REP 105 -- Coordinate Frames for Mobile Platforms