@article {2016h-SteCogOriBueFra,
	title = {Ground and Aerial Mutual Localization using Anonymous Relative-Bearing Measurements},
	journal = {IEEE Transaction on Robotics},
	volume = {32},
	year = {2016},
	month = {09/2017},
	pages = {1133-1151},
	abstract = {We present a  decentralized algorithm for estimating mutual poses (i.e., relative positions and orientations) in a group of mobile robots. The algorithm uses only anonymous relative-bearing measurements obtainable, e.g., using onboard monocular cameras, and onboard motion measurements, such as inertial ones (acceleration and angular velocity). 
Onboard relative-bearing sensors supply anonymous measurements, i.e., they  provide the directions along which other robots are located but each direction is not associated to any robot (identities are unknown).
The issue of anonymity is often overlooked in theory but represents a real problem in practice, especially when employing onboard vision.
The solution is first presented for ground robots, in SE(2), and then for aerial robots, in SE(3), in order to emphasize the difference between the two cases.
The proposed method is based on a two-step approach, the first uses instantaneous geometrical arguments on the anonymous measurements in order to retrieve the most likely unscaled relative configurations together with the identities, the second uses a numeric Bayesian filtering in order to take advantage of the motion model over time and to retrieve the scale.
The proposed method exhibits robustness w.r.t. false positives and negatives of the robot detector.
An extensive experimental validation of the algorithm is performed using Khepera III ground mobile robots and quadrotor aerial robots.},
	attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2016h-SteCogOriBueFra-preprint.pdf , https://homepages.laas.fr/afranchi/robotics/sites/default/files/2016h-SteCogOriBueFra.mp4},
	author = {Paolo Stegagno and Marco Cognetti and Giuseppe Oriolo and Heinrich H. B{\"u}lthoff and Antonio Franchi}
}
@conference {2012c-CogSteFraOriBue,
	title = {3D Mutual Localization with Anonymous Bearing Measurements},
	booktitle = {2012 IEEE Int. Conf. on Robotics and Automation},
	year = {2012},
	month = {05/2012},
	address = {St. Paul, MN},
	abstract = {We present a decentralized algorithm for estimating mutual 3-D poses in a group of mobile robots, such as a team of UAVs. Our algorithm uses bearing measurements reconstructed, e.g., by a visual sensor, and inertial measurements coming from the robot IMU. Since identification of a specific robot in a group would require visual tagging and may be cumbersome in practice, we simply assume that the bear- ing measurements are anonymous. The proposed localization method is a non-trivial extension of our previous algorithm for the 2-D case, and exhibits similar performance and robustness. An experimental validation of the algorithm has been performed using quadrotor UAVs.},
	keywords = {Distributed algorithms, Estimation, Localization, Localization of aerial robots, Multi-robot systems},
	attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2012c-CogSteFraOriBue.pdf},
	author = {Marco Cognetti and Paolo Stegagno and Antonio Franchi and Giuseppe Oriolo and Heinrich H. B{\"u}lthoff}
}
@conference {2012l-CogSteFraOri,
	title = {Two Measurement Scenarios for Anonymous Mutual Localization in Multi-UAV Systems},
	booktitle = {2nd IFAC Workshop on Multivehicle Systems},
	year = {2012},
	month = {10/2012},
	address = {Espoo, Finland},
	keywords = {Estimation, Localization, Localization of aerial robots, Multi-robot systems},
	attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2012l-CogSteFraOri-preprint.pdf},
	author = {Marco Cognetti and Paolo Stegagno and Antonio Franchi and Giuseppe Oriolo}
}
@conference {2011m-SteCogFraOri,
	title = {Mutual Localization using Anonymous Bearing Measurements},
	booktitle = {2011 IEEE/RSJ Int. Conf. on Intelligent Robots and Systems},
	year = {2011},
	month = {09/2011},
	pages = {469-474},
	address = {San Francisco, CA},
	abstract = {This paper addresses the problem of mutual localization in multi-robot systems in presence of anonymous (i.e., without the identity information) bearing-only measurements. The solution of this problem is relevant for the design and implementation of any decentralized multi-robot algorithm/control. A novel algorithm for probabilistic multiple registration of these measurements is presented, where no global localization, distances, or identity are used. With respect to more conventional solutions that could be conceived on the basis of the current literature, our method is theoretically suitable for tasks requiring frequent, many-to-many encounters among agents (e.g., formation control, cooperative exploration, multiple-view environment sensing). An extensive experimental study validates our method and compares it with the fullinformative case of bearing plus-distance measurements. The results show that the proposed localization system exhibits an accuracy commensurate to our previous method [1] which uses bearing-plus-distance information.},
	keywords = {Distributed algorithms, Estimation, Localization, Multi-robot systems},
	attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2011m-SteCogFraOri-preprint.pdf , https://homepages.laas.fr/afranchi/robotics/sites/default/files/2011m-SteCogFraOri.mp4},
	author = {Paolo Stegagno and Marco Cognetti and Antonio Franchi and Giuseppe Oriolo}
}
