This is a project I worked on for the NSF-REU Program in Pervasive and Mobile Computing at Auburn University in the summer of 2010. The project involves 6-12 uninhabited aerial vehicles (UAVs), built using Multiplex Easy Star airframes and ArduPilot UAV controllers. A collision avoidance algorithm will run on a ground control station (GCS), and will tell the planes to move to points in 3D space to avoid impact. To facilitate bidirectional communication, Chester Hamilton and I have constructed a ZigBee mesh network using XBee-PRO modules. We edited the ArduPilot software to allow the GCS to override the plane's current path in the interest of avoidance. We used and modified NewSoftSerial to let the XBee talk to the microcontroller without any serial bus conflicts.

NSF logo
Auburn University Seal

An additional, relatively cool project Chester and I worked on was researching the performance of the ZigBee PRO mesh network that will be used with the UAVs. While the UAVs will never fly out of the GCS's XBee radio range, we decided to see what happens when nodes move around in a multi-hop network. The results are actually interesting, if you're into that kind of hard core network benchmarking action. Check out the links to the paper and presentations on the subject below.

Fruits of Labor

  • Code: Code and documentation for all of the work we have done is available at this github.
  • Intro Slides: Here are the slides for a short talk that I gave on embedded systems and the project.
  • Midterm Slides: We've made a pretty midterm presentation on our work, 5 weeks into the REU. Check it out here.
  • Paper: Chester and I have written a paper on analyzing the performance of ZigBee PRO mesh networks, particularly with moving nodes. If you ever wanted to learn more about mesh routing algorithms, this paper is for you.
  • Final Slides: Here are our slides to accompany the final paper. They summarize the paper perfectly incomprehensibly.
  • Poster: We have an academic poster to go with it too!
  • DIY Drones Post: Here is a DIY Drones blog post on our work with the ArduPilot and XBee communication.
  • New (6/11/11) Paper Published: PennScience, a Penn undergraduate research journal, has published a slightly abridged version of our paper. It is viewable on pages 29-33 here (Flash required).

Further Readings