Photo d'Alex Feldmamn, reprise par IEEE Spectrum
In this project, we propose to capitalize on the research and know-how on Ultra Wide Band Technology as well as multi-robot distributed search and localization techniques acquired in previous MICS phases. The goal is to build a system that allows a team of mobile robots to locate themselves and other robots with high precision (order of a cm) very frequently (maybe once per second) and securely, in order to perform collaborative , such as distributed search, coverage, or mapping. We assume that the environment forbids the use of GPS (typically because it is indoors). The project will focus on distributed algorithms that can be efficiently implemented and on development of low power implementations on integrated circuits.
In a first phase, the mobile robots would be equipped with UWB impulse radio transmitters, and fixed, wall mounted UWB base stations are equipped with UWB receivers. This is optimal in a first phase as UWB senders are considerably simpler than receivers. The mobile robots transmit non coordinated trains of impulses, which are coded using cryptographic time hopping sequences unique to each robot. The base stations process the aggregate trains of impulses, recognize the signatures of all robots, and compute ranging information. Both robots and base stations are also equipped with standard communication channels used in mobile robotics (802.11, ZigBee or Bluetooth) for robot-to-robot and robot-to-base station communication.
In this phase we will apply robust ranging and detection techniques that were developed in MICS phase 2 and elsewhere to the problem of detection of one user among N. A detailed implementation will be analyzed with Matlab to validate the range of SNRs and density of nodes over which such an approach is feasible. On the base station side, we will also investigate emerging algorithms based on compressive sensing, as alternatives to the more classical maximum likelihood estimation methods. On the sender side, we will focus on developing low cost, low power specialized emitter and will implement a prototype with an integrated circuit. With the results of the first phase, the base station is passive from a radio viewpoint. While this has advantages of its own (stealthiness), it does not allow secure ranging as a two way channel is required for existing protocols. Web page of MICS: www.mics.org. Webpage of UWBNet
- Alexander Bahr, Alexander Feldman, James Colli-Vignarelli, Stephan Robert, Catherine Dehollain, and Alcherio Martinoli, « Modeling and Benchmarking Ultra-Wideband Localization for Mobile Robots », 2012 IEEE International Conference on Ultra-Wideband (ICUWB)
- Alexander Feldman, Alexander Bahr, James Colli-Vignarelli, Stephan Robert, Catherine Dehollain and Alcherio Martinoli, « Towards the Deployment of an Ultra-Wideband Localization Testbed », VTC Fall, September 5-8, 2011, San Francisco, USA.
- James Colli-Vignarelli, Alexander Feldman, Stephan Robert, Catherine Dehollain, « A Discrete Component Impulse Radio Ultra-Wide Band (IR-UWB) Receiver with I/Q Demodulation » PRIME, July 4-8, 2011, Trento, Italy. Gold Leaf Paper Award.