The importance of calibration motion

Calibration Anywhere is targetless automatic sensor calibration software developed by Main Street Autonomy.

Calibration Anywhere does not require a specific motion, but does need sensor observations of the scene from many different poses. Observable features in the environment become the effective checkerboards and targets used to calibrate the sensors.

Calibration motion requirements

• Movement that includes translation, rotation, and loop closure
• Nearby large static structure: closer and larger is better
• Some small part of the recording should be while the system is stationary

Calibration motion recommendations

• Figure-8 movement with a right-hand turn, left-hand turn, and two loop closures
• Three point turn (aka K-turn) with a right-hand turn, left-hand turn, and a loop closure

Calibration motion guide

Procedure

1. Start recording with the system (robot, vehicle, drone, etc) stationary, positioned very close to tall static structure that fills the field of view of some sensors

   • Ideally start within 1 meter of the static structure
   • The best static structure is large and textured, including:
     • Brick walls, door frames, buildings with windows
     • Rocks and other large outdoor features
     • Pallets or shelves with boxes
     • Stationary vehicles or robots

2. Move the system in a figure-8 pattern or three-point turn or other translation/rotation pattern

   • Stay as close as possible to the tall static structure

3. Stop the system and then end the recording

The calibration motion can be customized to suit your needs. A figure-8 or three-point turn is not specifically required, other motion can work. Contact us for more information.

Tips

• Move the system manually, or via teleoperation, or autonomously
• Ensure operators don’t fully obscure any sensor’s view
• Move quickly enough to complete all motions within ~60 seconds
  • A walking or jogging pace is usually appropriate for smaller systems (like a small robot or AGV), while a parking-lot-appropriate driving speed works well for larger systems (like a vehicle)
  • Abrupt motion and faster speeds while turning will cause the robot to pitch and roll more, which is beneficial

Recording duration

• Target 30-60 seconds
• Minimize the recording duration as much as possible
• Start the recording immediately before starting the movement
• Stop the recording as soon as the movement has completed