ros2 transforms ai_generated true

tf2.ExtrapolationException: Lookup would require extrapolation into the future

ID: ros2/tf2-extrapolation-into-future

Also available as: JSON · Markdown
88%Fix Rate
92%Confidence
3Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
any active — — —

Root Cause

tf2 transform lookup fails when requesting a transform at a timestamp newer than the latest available transform. Common when sensor data timestamp is slightly ahead of tf broadcaster, or when using sim_time with clock skew between nodes.

generic

Workarounds

  1. 92% success Use tf2_ros.Buffer.lookup_transform with timeout for blocking wait 
    transform = tf_buffer.lookup_transform('map', 'base_link', rclpy.time.Time(), timeout=Duration(seconds=1.0))
  2. 90% success Use Time(0) to get the latest available transform instead of a specific timestamp 
    transform = tf_buffer.lookup_transform('map', 'base_link', rclpy.time.Time())  # latest available, no extrapolation
  3. 85% success When using sim_time, ensure all nodes use use_sim_time:=true consistently 
    ros2 launch my_pkg my_launch.py use_sim_time:=true  # all nodes must agree on time source

Dead Ends

Common approaches that don't work:

  1. Use rospy.Time.now() / self.get_clock().now() as lookup time 88% fail

    Current time may be ahead of the latest published transform. Transform publishers have latency. Requesting 'now' often extrapolates into the future.

  2. Increase tf buffer size to store more transforms 82% fail

    Buffer size stores history, not future. The issue is timing, not storage. More history doesn't help when the requested time is in the future.