Operation - Taking and verifying a log#

This section is outdated

Note that this section is outdated. We are working on updating it.

Requires: Operation - Make it Move

Requires: Calibration - Camera

Result: A verified log.



Use note directives for basic highlighting.

This assumes that you have the folder /data/logs on the Duckiebot. If not, SSH into your robot and execute:

sudo mkdir /data/logs


It is recommended but not required that you log to your USB and not to your SD card.

Record the log#

Option: Minimal Logging on the Duckiebot#

dts duckiebot demo --demo_name make_log_docker --duckiebot_name ![DUCKIEBOT_NAME] --package_name duckietown_demos

This will only log the imagery, camera_info, the control commands and a few other essential things.

Option: Full Logging on the Duckiebot#

To log everything that is being published, run the base container on the Duckiebot:

dts duckiebot demo --demo_name make_log_full_docker --duckiebot_name ![DUCKIEBOT_NAME] --package_name duckietown_demos

Stop logging#

You can stop the recording process by stopping the container:

docker -H ![DUCKIEBOT_NAME].local stop demo_make_log_docker

or demo_make_log_full_docker as the case may be. You can also do this through the portainer interface.

Getting the log#

Using a USB drive#

If you mounted a USB drive, you can unmount it and then remove the USB drive containing the logs (recommended).

Using SCP#

Otherwise you can copy the logs from your robot onto your laptop. Assuming they are on the same network execute:

scp ![linux_username]@![hostname].local:/data/logs/* ![path-to-local-folder]

You can also download a specific log instead of all by replacing * with the filename.

Verify a log#


This procedure requires rosbag to be installed. If you have not installed that already, you can do so via:

sudo apt-get install python3-rosbag

Either copy the log to your laptop or from within your container do

rosbag info ![FULL_PATH_TO_BAG] --freq


  • verify that the “duration” of the log seems “reasonable” - it’s about as long as you ran the log command for

  • verify that the “size” of the log seems “reasonable” - the log size should grow at about 220MB/min

  • verify in the output that your camera was publishing very close to 30.0Hz and verify that your virtual joysick was publishing at a rate of around 26Hz.

An example of the output looks like this:

path:        avlduck2_2020-08-05-01-54-18.bag
version:     2.0
duration:    12.7s
start:       Aug 04 2020 21:54:18.73 (1596592458.73)
end:         Aug 04 2020 21:54:31.42 (1596592471.42)
size:        69.9 MB
messages:    756
compression: none [77/77 chunks]
types:       sensor_msgs/CameraInfo      [c9a58c1b0b154e0e6da7578cb991d214]
            sensor_msgs/CompressedImage [8f7a12909da2c9d3332d540a0977563f]
topics:      /avlduck2/camera_node/camera_info        374 msgs @ 29.9 Hz : sensor_msgs/CameraInfo     
            /avlduck2/camera_node/image/compressed   382 msgs @ 29.8 Hz : sensor_msgs/CompressedImage