New Packages: Datalink Toolkit for Remote Operation with High-Latency and Low-Bandwidth Connections

| No Comments | No TrackBacks
From Dmitry Berenson via ros-users@

The ARC Lab at WPI is releasing the Datalink Toolkit ROS package, designed to for remote operation of a robot over a high-latency and low-bandwidth datalink. The package was developed and extensively tested as part of the DARPA robotics challenge, though it is not specific to a type of robot.

The package allows the user to easily set up relays and compression methods for a single-master system. These relays avoid duplicating data sent over the datalink while compressing common datatypes (i.e. point-clouds and images) to minimize bandwidth usage.
The toolkit includes both message-based and service-based relays so that data can be sent on-demand or at a specified frequency. The service-based relays are more robust in low-bandwidth conditions, guaranteeing the synchronization of camera images and camera info messages, and allow more reconfiguration while running.

The key features of the package are:
- Generic relays with integrated rate throttling for all message types
- Dedicated relays with rate throttling for images and pointclouds
- Generic service-based relays with integrated rate throttling for all message types
- Dedicated service-based relays with integrated rate throttling for images and pointclouds
- Image resizing and compression using methods from OpenCV and image_transport
- Pointcloud voxel filtering and compression using methods from PCL, Zlib, and other algorithms. (Note: pointcloud compression is provided in a separate library that can be easily integrated with other projects)
- Launch files for easy use of the datalink software with RGBD cameras
- Works with ROS Hydro

Overall performance:
- Reliable data transfer for a wide range of bandwidths and latencies (e.g. at DRC Trials: 1Mb/s - 100 Kb/s bandwidth, 100ms - 1000ms latency)
- Pointcloud compression >8x depending on compression algorithm (without voxel filtering)
- Pointcloud compression >20x depending on compression algorithm (with voxel filtering)
- Image compression equivalent to image_transport (without image resizing) or better (with resizing)

Performance comparison with ROS for image transfer:
- 1.5x more images/second at 1Mb/s (grayscale image size 320x240)
- 2x more images/second at 100Kb/s (grayscale image size 320x240)
- 3x more images/second at 50Kb/s (grayscale image size 320x240)


For more information, please see the wiki here:

Get the package from our git repository here:

No TrackBacks

TrackBack URL: http://www.ros.org/mt-tb.cgi/991

Leave a comment

Find this blog and more at planet.ros.org.


Please submit content to be reviewed by emailing ros-news@googlegroups.com.

Monthly Archives

About this Entry

This page contains a single entry by Tully Foote published on April 21, 2014 12:40 PM.

New Package: moveit_visual_tools was the previous entry in this blog.

Second ROS-Industrial community forum on April 28th at 5CET, Accepting lightning talks is the next entry in this blog.

Find recent content on the main index or look in the archives to find all content.