Multi-robot exploration

In the Multi-SRG method, a roadmap of the explored area, with the associate safe region, is built in the form of a compact data structure, called Sensor-based Random Graph. This is incrementally expanded by the robots by using a randomized local planner which automatically realizes a trade-off between information gain and navigation cost.

The Multi-SRG method [1],[2],[3] is a decentralized cooperative exploration strategy for mobile robots based its former version Multi-SRT [4],[5]. Connection structures, called bridges, are incrementally added to the graph to create shortcuts and improve the connectivity of the roadmap. Decentralized cooperation and coordination mechanisms are used so as to guarantee exploration efficiency and avoid conflicts.

The video is a summary of [1],[2],[3].

See also the exploration page for an overview on the topic.

 

explExp1

explExp2

Further informations at the La Sapienza Robotics Laboratory web-page.

 

Sensor-based Random Tree (former version of SRG)

The Multi-SRT method [4],[5] is a cooperative exploration strategy for a team of mobile robots. The method proceeds from the parallelization of the single-robot SRT technique and is based on the randomized incremental generation of a collection of data structures called Sensor-based Random Trees (SRT), each representing a roadmap of an explored area with an associated safe region. Decentralized cooperation and coordination mechanisms are used to improve the exploration efficiency and to avoid conflicts.

simulations 

1) The exploration is started with the robots scattered in the environment (as if they had been parachuted)

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2) The exploration is started with the robots grouped in a cluster (more realistic for environments with a single main entrance).

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3) Clustered start in a office-like enviroment.

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4) Focus on the switching network topology. Image

Further informations at the La Sapienza Robotics Laboratory web-page.


References

  1. A. Franchi, Freda, L., Oriolo, G., and Vendittelli, M., A decentralized strategy for cooperative robot exploration, in ACM International Conference Proceeding Series, Proceedings of the 1st international conference on Robot communication and coordination, Athens, Greece, 2007, vol. 318.
  2. A. Franchi, Freda, L., Marchionni, L., Oriolo, G., and Vendittelli, M., Decentralized cooperative exploration: Implementation and experiments, in 10th Int. Conf. on Intelligent Autonomous Systems, Baden-Baden, Germany, 2008, pp. 348-355.
  3. A. Franchi, Freda, L., Oriolo, G., and Vendittelli, M., The Sensor-based Random Graph Method for Cooperative Robot Exploration, IEEE/ASME Transaction on Mechatronics, vol. 14, no. 2, pp. 163-175, 2009.
  4. A. Franchi, Communication and Coordination Strategies for Multi-agent Robotic Exploration, "La Sapienza" University of Rome, 2005.
  5. A. Franchi, Freda, L., Oriolo, G., and Vendittelli, M., A Randomized Strategy for Cooperative Robot Exploration, in 2007 IEEE Int. Conf. on Robotics and Automation, Rome, Italy, 2007, pp. 768-774.

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