Learn Robotics
Reference

Robotics Cheat Sheet

A quick-reference guide for coordinate frames, common data types, units, and debugging tips. Bookmark this page.

Standard Convention

Robotics uses right-handed coordinate systems. This is the standard convention used across all major robotics frameworks and simulators.

Body Frame (base_link)
  • X — Forward
  • Y — Left
  • Z — Up
World Frame
  • X — East
  • Y — North
  • Z — Up

Optical Frame (Camera)

Cameras use a different convention (OpenCV standard):

  • Z — Forward (into the scene)
  • X — Right
  • Y — Down
FrameParentDescription
world / map(root)Global fixed frame, drift-free
odomworldContinuous odometry frame, may drift over time
base_linkodomRobot body center, rigidly attached to chassis
base_footprintbase_linkProjection of base_link on ground plane
laser_linkbase_linkLiDAR sensor origin
camera_linkbase_linkCamera mounting point
camera_opticalcamera_linkCamera optical center (Z-forward)
imu_linkbase_linkIMU sensor origin