@conference {2021h-CoeSarLeeBalFraKonOtt, title = {Hierarchical Control of Redundant Aerial Manipulators with Enhanced Field of View}, booktitle = {2021 Int. Conf. on Unmanned Aircraft Systems}, year = {2021}, month = {Sep.}, address = {Athens, Greece}, author = {Andre Coelho and Yuri Sarkisov and Jongseok Lee and Ribin Balachandran and Antonio Franchi and Konstantin Kondak and Christian Ott} } @article {2021g-OllTogSuaLeeFra, title = {Past, Present, and Future of Aerial Robotic Manipulators}, journal = {IEEE Transactions on Robotics}, year = {2021}, doi = {10.1109/TRO.2021.3084395}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2021g-OllTogSuaLeeFra.pdf}, author = {Anibal Ollero and Marco Tognon and Alejandro Suarez and Dongjun Lee and Antonio Franchi} } @article {2021j-BarFraOri, title = {Towards Safe Human-Quadrotor Interaction: Mixed-Initiative Control via Real-Time NMPC}, journal = {IEEE Robotics and Automation Letters, Special Issue on Shared Autonomy for Physical Human-Robot Interaction}, volume = {6}, year = {2021}, pages = {7611-7618}, abstract = {This paper presents a novel algorithm for blending human inputs and automatic controller commands, guarantee- ing safety in mixed-initiative interactions between humans and quadrotors. The algorithm is based on nonlinear model predictive control (NMPC) and involves using the state solution to assess whether safety- and/or task-related rules are met to mix control authority. The mixing is attained through the convex combination of human and actual robot costs and is driven by a continuous function that measures the rules{\textquoteright} violation. To achieve real-time feasibility, we rely on an efficient real-time iteration (RTI) variant of a sequential quadratic programming (SQP) scheme to cast the mixed-initiative controller. We demonstrate the effectiveness of our algorithm through numerical simulations, where a second autonomous algorithm is used to emulate the behavior of pilots with different skill levels. Simulations show that our scheme provides suitable assistance to pilots, especially novices, in a workspace with obstacles while underpinning computational efficiency.}, doi = {10.1109/LRA.2021.3096502}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2021j-BarFraOri.pdf , https://homepages.laas.fr/afranchi/robotics/sites/default/files/2021j-BarFraOri.mp4}, author = {Barbara Barros Carlos and Antonio Franchi and Giuseppe Oriolo} } @article {2021b-CoeSarWu_MisSinDieFraKonOtt, title = {Whole-Body Teleoperation and Shared Control of Redundant Robots with Applications to Aerial Manipulation}, journal = {Journal of Intelligent \& Robotic Systems}, volume = {102}, year = {2021}, doi = {10.1007/s10846-021-01365-7}, author = {Andre Coelho and Yuri Sarkisov and Xuwei Wu and Hrishik Mishra and Harsimran Singh and Alexander Dietrich and Antonio Franchi and Konstantin Kondak and Christian Ott} } @conference {2020k-UmiTogSanOriFra, title = {Communication-based and Communication-less approaches for Robust Cooperative Planning in Construction with a Team of UAVs}, booktitle = {2020 Int. Conf. on Unmanned Aircraft Systems}, year = {2020}, month = {07/2020}, address = {Athens, Greece}, abstract = {In this paper, we analyze the coordination problem of groups of aerial robots for assembly applications. With the enhancement of aerial physical interaction, construction applications are becoming more and more popular. In this domain, the multi-robot solution is very interesting to reduce the execution time. However, new methods to coordinate teams of aerial robots for the construction of complex structures are required. In this work, we propose an assembly planner that considers both assembly and geometric constraints imposed by the particular desired structure and employed robots, respectively. An efficient graph representation of the task dependencies is employed. Based on this framework, we design two assembly planning algorithms that are robust to robot failures. The first is centralized and communication-based. The second is distributed and communication-less. The latter is a solution for scenarios in which the communication network is not reliable. Both methods are validated by numerical simulations based on the assembly scenario of Challenge 2 of the robotic competition MBZIRC2020.}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2020k-UmiTogSanOriFra.pdf , https://homepages.laas.fr/afranchi/robotics/sites/default/files/2020k-UmiTogSanOriFra.mp4}, author = {Elena Umili and Marco Tognon and Dario Sanalitro and Giuseppe Oriolo and Antonio Franchi} } @conference {2019f-SarKimBicTseOttFraKon, title = {Development of SAM: cable-Suspended Aerial Manipulator}, booktitle = {2019 IEEE Int. Conf. on Robotics and Automation}, year = {2019}, month = {05/2019}, address = {Montreal, Canada}, abstract = { High risk of a collision between rotor blades and the obstacles in a complex environment imposes restrictions on the aerial manipulators. To solve this issue, a novel system cable-Suspended Aerial Manipulator (SAM) is presented in this paper. Instead of attaching a robotic manipulator directly to an aerial carrier, it is mounted on an active platform which is suspended on the carrier by means of a cable. As a result, higher safety can be achieved because the aerial carrier can keep a distance from the obstacles. For self-stabilization, the SAM is equipped with two actuation systems: winches and propulsion units. This paper presents an overview of the SAM including the concept behind, hardware realization, control strategy, and the first experimental results.}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2019f-SarKimBicTseOttFraKon-preprint.pdf}, author = {Yuri Sarkisov and Min J. Kim and Davide Bicego and D. Tsetserukou and Christian Ott and Antonio Franchi and Konstantin Kondak} } @article {2018m-OllHerFraAntKonSanVigSanTruBalAndRod, title = {The AEROARMS Project: Aerial Robots with Advanced Manipulation Capabilities for Inspection and Maintenance}, journal = {IEEE Robotics and Automation Magazine, Special Issue on Floating-base (Aerial and Underwater) Manipulation}, volume = {25}, year = {2018}, month = {12/2018}, pages = {12-23}, abstract = {This paper summarizes new aerial robotic manipu- lation technologies and methods, required for outdoor industrial inspection and maintenance, developed in the AEROARMS project. It presents aerial robotic manipulators with dual arms and multi-directional thrusters. It deals with the control systems, including the control of the interaction forces and the compliance, the teleoperation, which uses passivity to tackle the trade- off between stability and performance, perception methods for localization, mapping and inspection, and planning methods, including a new control-aware approach for aerial manipulation. Finally, it describes a novel industrial platform with multi- directional thrusters and a new arm design to increase the robustness in industrial contact inspections. The lessons learned in the application to outdoor aerial manipulation for inspection and maintenance are pointed out.}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2018m-OllHerFraAntKonSanVigSanTruBalAndRod-preprint_3.pdf}, author = {Anibal Ollero and Guillermo Heredia and Antonio Franchi and Gianluca Antonelli and Konstantin Kondak and Alberto Sanfeliu and Antidio Viguria and Jose R. Martinez-de Dios and Francesco Pierri and Juan Cort{\'e}s and A. Santamaria-Navarro and Miguel A. Trujillo and Ribin Balachandran and Juan Andrade-Cetto and Angel Rodriguez} } @article {2015i-FraSteOri, title = {Decentralized Multi-Robot Encirclement of a 3D Target with Guaranteed Collision Avoidance}, journal = {Autonomous Robots}, volume = {40}, year = {2016}, month = {02/2016}, pages = {245-265}, abstract = {We present a control framework for achieving encirclement of a target moving in 3D using a multi-robot system. Three variations of a basic control strategy are proposed for different versions of the encirclement problem, and their effectiveness is formally established. An extension ensuring maintenance of a safe inter-robot distance is also discussed. The proposed framework is fully decentralized and only requires local communication among robots; in particular, each robot locally estimates all the relevant global quantities. We validate the proposed strategy through simulations on kinematic point robots and quadrotor UAVs, as well as experiments on differential-drive wheeled mobile robots.}, keywords = {Motion control of multiple robots}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/1307.7170v2.pdf , https://homepages.laas.fr/afranchi/robotics/sites/default/files/1307.7170v1.pdf}, author = {Antonio Franchi and Paolo Stegagno and Giuseppe Oriolo} } @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 {2014g-GagOriBueFra, title = {Image-based Road Network Clearing without Localization and without Maps using a Team of UAVs}, booktitle = {2014 European Control Conference}, year = {2014}, month = {06/2014}, pages = {1902-1908}, address = {Strasbourg, France}, abstract = {We address the problem of clearing an arbitrary and unknown network of roads using an organized team of Unmanned Aerial Vehicles (UAVs) equipped with a monocular down-facing camera, an altimeter, plus high-bandwidth short- range and low-bandwidth long-range communication systems. We allow the UAVs to possibly split in several subgroups. In each subgroup a leader guides the motion employing a hierarchical coordination. A feature/image-based algorithm guides the subgroup toward the unexplored region without any use of global localization or environmental mapping. At the same time all the entry-points of the the explored region are kept under control, so that any moving object that enters or exits the previously cleared area. Simulative results on real aerial images demonstrate the functionalities and the effectiveness of the proposed algorithm. }, keywords = {Aerial Robotics, Exploration, Motion control of multiple robots, Patrolling / Surveillance, Pursuit-evasion / Clearing}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2014g-GagOriBueFra-preprint.pdf , https://homepages.laas.fr/afranchi/robotics/sites/default/files/2014g-GagOriBueFra-video.mp4}, author = {Matteo Gagliardi and Giuseppe Oriolo and Heinrich H. B{\"u}lthoff and Antonio Franchi} } @article {2013g-FraOriSte, title = {Mutual Localization in Multi-Robot Systems using Anonymous Relative Measurements}, journal = {The International Journal of Robotics Research}, volume = {32}, year = {2013}, month = {09/2013}, pages = {1303-1322}, abstract = {We propose a decentralized method to perform mutual localization in multi-robot systems using anonymous relative measurements, i.e., measurements that do not include the identity of the measured robot. This is a challenging and practically relevant operating scenario that has received little attention in the literature. Our mutual localization algorithm includes two main components: a probabilistic multiple registration stage, which provides all data associations that are consistent with the relative robot measurements and the current belief, and a dynamic filtering stage, which incorporates odometric data into the estimation process. The design of the proposed method proceeds from a detailed formal analysis of the implications of anonymity on the mutual localization problem. Experimental results on a team of differential-drive robots illustrate the effectiveness of the approach, and in particular its robustness against false positives and negatives that may affect the robot measurement process. We also provide an experimental comparison that shows how the proposed method outperforms more classical approaches that may be designed building on existing techniques. The source code of the proposed method is available within the MLAM ROS stack.}, keywords = {Localization of ground robots}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2013g-FraOriSte.pdf , https://homepages.laas.fr/afranchi/robotics/sites/default/files/2013g-FraOriSte.mp4}, author = {Antonio Franchi and Giuseppe Oriolo and Paolo Stegagno} } @article {2013i-CenFraMarOri, title = {Simultaneous Calibration of Odometry and Sensor Parameters for Mobile Robots}, journal = {IEEE Transaction on Robotics}, volume = {29}, year = {2013}, month = {04/2013}, pages = {475-492}, abstract = {Consider a differential-drive mobile robot equipped with an on-board exteroceptive sensor that can estimate its own motion, e.g., a range-finder. Calibration of this robot involves estimating six parameters: three for the odometry (radii and distance between the wheels), and three for the pose of the sensor with respect to the robot. After analyzing the observability of this problem, this paper describes a method for calibrating all parameters at the same time, without the need for external sensors or devices, using only the measurement of the wheels velocities and the data from the exteroceptive sensor. The method does not require the robot to move along particular trajectories. Simultaneous calibration is formulated as a maximum-likelihood problem and the solution is found in a closed form. Experimental results show that the accuracy of the proposed calibration method is very close to the attainable limit given by the Cram{\`e}r{\textendash}Rao bound.}, keywords = {Calibration, Calibration of ground robots, Estimation}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2013i-CenFraMarOri.pdf}, author = {Andrea Censi and Antonio Franchi and Luca Marchionni and Giuseppe Oriolo} } @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 {2012j-SpiFraOriBueRob, title = {Aerial Grasping of a Moving Target with a Quadrotor UAV}, booktitle = {2012 IEEE/RSJ Int. Conf. on Intelligent Robots and Systems}, year = {2012}, month = {10/2012}, pages = {4985-4992}, address = {Vilamoura, Portugal}, abstract = {For a quadrotor aircraft, we study the problem of planning a trajectory that connects two arbitrary states while allowing the UAV to grasp a moving target at some intermediate time. To this end, two classes of canonical grasping maneuvers are defined and characterized. A planning strategy relying on differential flatness is then proposed to concatenate one or more grasping maneuvers by means of spline-based subtrajectories, with the additional objective of minimizing the total transfer time. The proposed planning algorithm is not restricted to pure hovering-to-hovering motions and takes into account practical constraints, such as the finite duration of the grasping phase. The effectiveness of the proposed approach is shown by means of physically-based simulations.}, keywords = {Motion Planning, Optimal Trajectory Planning}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2012j-SpiFraOriBueRob.pdf , https://homepages.laas.fr/afranchi/robotics/sites/default/files/2012j-SpiFraOriBueRob.mp4}, author = {Riccardo Spica and Antonio Franchi and Giuseppe Oriolo and Heinrich H. B{\"u}lthoff and Paolo Robuffo Giordano} } @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} } @conference {2010c-FraSteDirOri, title = {Distributed Target Localization and Encirclement with a Multi-robot System}, booktitle = {7th IFAC Symposium on Intelligent Autonomous Vehicles}, year = {2010}, month = {09/2010}, address = {Lecce, Italy}, abstract = {This paper presents a control scheme for localizing and encircling a target using a multi-robot system. The task is achieved in a distributed way, in that each robot only uses local information gathered by on-board relative-position sensors assumed to be noisy, anisotropic, and unable to detect the identity of the measured object. Communication between the robots is provided by limited-range transceivers. Experimental results with stationary and Multi-robot systems, distributed control, mutual localization, encirclement.moving targets support the theoretical analysis. }, keywords = {Decentralized control, Distributed algorithms, Estimation, Formation control, Multi-robot systems}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2010c-FraSteDirOri-preprint.pdf}, author = {Antonio Franchi and Paolo Stegagno and Maurizio Di~Rocco and Giuseppe Oriolo} } @conference {2010d-FraOriSte, title = {Probabilistic Mutual Localization in Multi-agent Systems from Anonymous Position Measures}, booktitle = {49th IEEE Conference on Decision and Control}, year = {2010}, month = {12/2010}, pages = {6534-6540}, address = {Atlanta, GA, USA}, abstract = {Recent research on multi-agent systems has produced a plethora of decentralized controllers that implicitly assume various degrees of agent localization. However, many practical arrangements commonly taken to allow and achieve localization imply some form of centralization, from the use of physical tagging to allow the identification of the single agent to the adoption of global positioning systems based on cameras or GPS. These devices clearly decrease the system autonomy and range of applicability, and should be avoided if possible. Following this guideline, this work addresses the mutual localization problem with anonymous relative position measures, presenting a robust solution based on a probabilistic framework. The proposed localization system exhibits higher accuracy and lower complexity ($O(n^2)$) than our previous method~[bib]2009c-FraOriSte[/bib]. Moreover, 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). The proposed localization system has been validated by means of an extensive experimental study}, keywords = {Distributed algorithms, Estimation, Localization, Multi-robot systems}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2010d-FraOriSte-preprint.pdf , https://homepages.laas.fr/afranchi/robotics/sites/default/files/2010d-FraOriSte.pdf}, author = {Antonio Franchi and Giuseppe Oriolo and Paolo Stegagno} } @conference {2010a-FraOriSte, title = {On the Solvability of the Mutual Localization Problem with Anonymous Position Measures}, booktitle = {2010 IEEE Int. Conf. on Robotics and Automation}, year = {2010}, month = {05/2010}, pages = {3193-3199}, address = {Anchorage, AK}, abstract = {This paper formulates and investigates a novel problem called Mutual Localization with Anonymous Position Measures. This is an extension of Mutual Localization with Position Measures, with the additional assumption that the identities of the measured robots are not known. A necessary and sufficient condition for the uniqueness of the solution is presented, which requires O(n^2/\log n) to be verified and is based on the notion of rotational symmetry in R^2. We also derive the relationship between the number of robots and the number of possible solutions, and classify the solutions in a number of equivalence classes which is linear in n. A control law is finally proposed that effectively breaks symmetric formations so as to guarantee unique solvability of the problem is also proposed; its performance is illustrated through simulations.}, keywords = {Estimation, Formation control, Localization, Multi-robot systems}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2010a-FraOriSte.pdf , https://homepages.laas.fr/afranchi/robotics/sites/default/files/ICRA10-Final.mp4}, author = {Antonio Franchi and Giuseppe Oriolo and Paolo Stegagno} } @mastersthesis {60, title = {Decentralized Methods for Cooperative Task Execution in Multi-robot Systems}, year = {2009}, month = {12/2009}, school = {"La Sapienza" University of Rome}, type = {PhD}, keywords = {Coverage, Decentralized control, Distributed algorithms, Estimation, Exploration, Formation control, Localization of ground robots, Middleware for robotics, Motion control of multiple robots, Multi-robot systems, Patrolling / Surveillance, Pursuit-evasion / Clearing}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2009-Franchi_PhDThesis.pdf}, author = {Antonio Franchi} } @article {2009a-FraOriSte, title = {Mutual Localization in a Multi-Robot System with Anonymous Relative Position Measures}, year = {2009}, month = {01/2009}, institution = {Department of Computer and System Sciences Antonio Ruberti}, abstract = {In this paper we formulate and solve the mutual localization problem for a multi-robot system under the assumption of anonymous relative position measures. The anonymity hypothesis can cause a combinatorial ambiguity in the inversion of the measure equation giving more than one possible solution to the problem. We propose MultiReg, an innovative algorithm aimed at obtaining sets ofpossible relative pose hypotheses, whose output is processed by a data associator and a multiple EKF to select the best hypothesis. We study the performance of the developed localization system using both simulations and real robot experiments.}, keywords = {Distributed algorithms, Estimation, Localization, Multi-robot systems}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2009a-FraOriSte.pdf}, author = {Antonio Franchi and Giuseppe Oriolo and Paolo Stegagno} } @conference {2009c-FraOriSte, title = {Mutual Localization in a Multi-Robot System with Anonymous Relative Position Measures}, booktitle = {2009 IEEE/RSJ Int. Conf. on Intelligent Robots and Systems}, year = {2009}, month = {11/2009}, pages = {3974-3980}, address = {St. Louis, MO}, abstract = {We address the mutual localization problem for a multi-robot system, under the assumption that each robot is equipped with a sensor that provides a measure of the relative position of nearby robots without their identity. Anonymity generates a combinatorial ambiguity in the inversion of the measure equations, leading to a multiplicity of admissible relative pose hypotheses. To solve the problem, we propose a two-stage localization system based on MultiReg, an innovative algorithm that computes on-line all the possible relative pose hypotheses, whose output is processed by a data associator and a multiple EKF to isolate and refine the best estimates. The performance of the mutual localization system is analyzed through experiments, proving the effectiveness of the method and, in particular, its robustness with respect to false positives (objects that look like robots) and false negatives (robots that are not detected) of the measure process.}, keywords = {Distributed algorithms, Estimation, Localization, Multi-robot systems}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2009c-FraOriSte.pdf , https://homepages.laas.fr/afranchi/robotics/sites/default/files/IROS09_MutualLoc.mp4}, author = {Antonio Franchi and Giuseppe Oriolo and Paolo Stegagno} } @article {2009b-FraFreOriVen, title = {The Sensor-based Random Graph Method for Cooperative Robot Exploration}, journal = {IEEE/ASME Transaction on Mechatronics}, volume = {14}, number = {2}, year = {2009}, note = {Winner of the IEEE RAS ICYA Best Paper Award 2010 link

}, month = {04/2009}, pages = {163-175}, abstract = {We present a decentralized cooperative exploration strategy for a team of mobile robots equipped with range finders. A roadmap of the explored area, with the associate safe region, is built in the form of a Sensor-based Random Graph (SRG). This is expanded by the robots by using a randomized local planner which automatically realizes a trade-off between information gain and navigation cost. The nodes of the SRG represent view configurations that have been visited by at least one robot, and are connected by arcs that represent safe paths. These paths have been actually traveled by the robots or added to the SRG to improve its connectivity. Decentralized cooperation and coordination mechanisms are used so as to guarantee exploration efficiency and avoid conflicts. Simulations and experiments are presented to show the performance of the proposed technique.}, keywords = {Coverage, Distributed algorithms, Exploration, Multi-robot systems}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2009b-FraFreOriVen.pdf}, author = {Antonio Franchi and Luigi Freda and Giuseppe Oriolo and Marilena Vendittelli} } @conference {2008a-FraFreMarOriVen, title = {Decentralized cooperative exploration: Implementation and experiments}, booktitle = {10th Int. Conf. on Intelligent Autonomous Systems}, year = {2008}, month = {07/2008}, pages = {348-355}, address = {Baden-Baden, Germany}, keywords = {Coverage, Distributed algorithms, Multi-robot systems}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2008a-FraFreMarOriVen.pdf}, author = {Antonio Franchi and Luigi Freda and Luca Marchionni and Giuseppe Oriolo and Marilena Vendittelli} } @conference {2007b-FraFreOriVen, title = {A decentralized strategy for cooperative robot exploration}, booktitle = {ACM International Conference Proceeding Series, Proceedings of the 1st international conference on Robot communication and coordination}, volume = {318}, number = {7}, year = {2007}, month = {11/2007}, address = {Athens, Greece}, keywords = {Coverage, Distributed algorithms, Multi-robot systems}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2007b-FraFreOriVen.pdf}, author = {Antonio Franchi and Luigi Freda and Giuseppe Oriolo and Marilena Vendittelli} } @conference {2007a-FraFreOriVen, title = {A Randomized Strategy for Cooperative Robot Exploration}, booktitle = {2007 IEEE Int. Conf. on Robotics and Automation}, year = {2007}, month = {04/2007}, pages = {768-774}, address = {Rome, Italy}, keywords = {Coverage, Decentralized control, Distributed algorithms, Multi-robot systems}, attachments = {https://homepages.laas.fr/afranchi/robotics/sites/default/files/2007a-FraFreOriVen.pdf}, author = {Antonio Franchi and Luigi Freda and Giuseppe Oriolo and Marilena Vendittelli} }