SSC Pacific
Communication Relays: ADCR



Using the ad hoc networking radio technology developed under AMCR, SSC Pacific started the ADCR project with the goal of producing a system that was more practical. Funded by the Office of the Secretary of Defense’ Joint Robotics Program (now Joint Ground Robotics Enterprise—JGRE) during FY05-06, ADCR produced a plug-and-play radio repeater system for the iRobot PackBot family of robots. The system included a robot-mounted Deployer Module that would deploy relay nodes as needed. The Deployer Module monitored the signal strength to the closest deployed relay node along the network route leading back to the operator control unit (OCU). Using the same predictive filter that commanded the AMCR mobile relays to stop, the Deployer Module would instead eject a relay node whenever the link was about to break.

Each first-generation Deployer Module took two slots in the PackBot payload bay and housed six relay nodes. To prevent interference between nearby relay nodes, only one node was active at any time while still inside the Deployer Module. The Deployer Module made sure that the node had joined the network before ejecting it and activating the next node, getting ready for the next deployment event. The relay nodes (called “bricks” colloquially) were self-righting. After ejection, a microcontroller in the relay node waited a few seconds (to ensure the brick came to rest), and then issued a command for the doors to open, thereby flipping the brick upright (regardless of how it landed) and releasing a folded spring-loaded antenna. Figure 2 shows the first-generation ADCR Deployer Module on a PackBot and a deployed relay brick.

Although this ADCR design was licensed to three manufacturers, none were produced commercially.

A first-generation ADCR Deployer Module on a PackBot and a deployed relay node.
Figure 2. A first-generation ADCR Deployer Module on a PackBot and a deployed relay node.

For further information, see:

  • Pezeshkian, N., Nguyen, H.G., and A. Burmeister, “Unmanned Ground Vehicle Radio Relay Deployment System for Non-line-of-sight Operations,” Proc. 13th IASTED Int. Conf. on Robotics and Applications, Wuerzburg, Germany, August 29-31, 2007. 
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Updated: 7/15/2013 10:31 AM EST   Published