@article {489,
	title = {Probabilistic Network Topology Prediction for Active Planning: An Adaptive Algorithm and Application},
	journal = {IEEE Transactions on Robotics},
	volume = {39},
	year = {2023},
	month = {feb},
	pages = {147{\textendash}164},
	doi = {10.1109/tro.2022.3189223},
	url = {https://doi.org/10.1109\%2Ftro.2022.3189223},
	author = {Liang Zhang and Zexu Zhang and Roland Siegwart and Jen Jen Chung}
}
@article {488,
	title = {Time-sensitive coverage control for non-holonomic and heterogeneous robots: An extremum seeking framework and application},
	journal = {IET Control Theory \&amp$\mathsemicolon$ Applications},
	year = {2023},
	month = {feb},
	doi = {10.1049/cth2.12434},
	url = {https://doi.org/10.1049\%2Fcth2.12434},
	author = {Liang Zhang and Jinghui Deng and Kun Zhou and Tao Yu and Jun Song and Shuping He}
}
@conference {Liang2022,
	title = {Energy Sharing Mechanism for a Freeform Robotic System - FreeBOT},
	booktitle = {2022 International Conference on Robotics and Automation (ICRA)},
	year = {2022},
	pages = {4232{\textendash}4238},
	publisher = {IEEE},
	organization = {IEEE},
	address = {Philadelphia, PA, USA},
	abstract = {Energy sharing in modular self-reconfigurable robots ensures the energy balance of the modules, thus allowing the system to work sustainably. This paper proposes an energy sharing mechanism for a novel modular self-reconfigurable robot that allows free connections among modules, termed as FreeBOT, such that each FreeBOT can share energy with peers through surface contact. Corresponding energy sharing rules are proposed to achieve an energy sharing network structure without invalid components. As alternative choices, several types of networks subjected to the above requirements are provided, which also maximize the number of FreeBOTs joining to share energy. We implement and test the prototype of the energy sharing mechanism on FreeBOT. The experimental results show that the mechanism can effectively achieve energy sharing among FreeBOTs.},
	keywords = {Automation, Prototypes, Robots},
	isbn = {978-1-7281-9682-4},
	doi = {10.1109/ICRA46639.2022.9811860},
	author = {Guanqi Liang and Yuxiao Tu and Lijun Zong and Junfeng Chen and Tin Lun Lam}
}
@article {471,
	title = {Self-Stabilizing Self-Assembly},
	journal = {IEEE Robotics and Automation Letters},
	volume = {7},
	year = {2022},
	pages = {9763-9769},
	doi = {10.1109/LRA.2022.3191795},
	author = {J{\'\i}lek, Martin and Str{\'a}nsk{\'a}, Kate{\v r}ina and Somr, Michael and Kulich, Miroslav and Zeman, Jan and P{\v r}eu{\v c}il, Libor}
}
@conference {Zhao2022,
	title = {SnailBot: A Continuously Dockable Modular Self-reconfigurable Robot Using Rocker-bogie Suspension},
	booktitle = {2022 International Conference on Robotics and Automation (ICRA)},
	year = {2022},
	pages = {4261{\textendash}4267},
	publisher = {IEEE},
	organization = {IEEE},
	address = {Philadelphia, PA, USA},
	abstract = {This paper proposes a novel modular self-assembling, self-reconfiguring robot with the 3D continuous dock called {\textquotedblleft}SnailBot{\textquotedblright}. SnailBot mainly consists of a spherical ferromagnetic shell and a six-wheel rocker chassis with embedded magnets. Unlike many other existing modular self-reconfigurable robots with fixed docking locations, SnailBot uses the 3D continuous dock to attach to its peers regardless of alignment. This freeform docking mechanism can greatly improve the efficiency of self-reconfiguration and reduce docking failures because there is nearly no constraint in the location of the connector. Compared with the existing freeform MSRR, SnailBot can form a more structurally stable connection to its peers without loss of connection efficiency. Owing to the excellent obstacle crossing ability of the rocker-bogie suspension, the robot can freely crawl on other modules in the form of a sliding sphere. Experiments demonstrate the basic actions of a single module and some applications of SnailBots, such as a manipulator.},
	keywords = {Automation, Connectors, Manipulators, Three-dimensional displays},
	isbn = {978-1-7281-9682-4},
	doi = {10.1109/ICRA46639.2022.9811779},
	author = {Da Zhao and Tin Lun Lam}
}
@article {490,
	title = {Distributed PDOP Coverage Control: Providing Large-Scale Positioning Service Using a Multi-Robot System},
	journal = {IEEE Robotics and Automation Letters},
	volume = {6},
	year = {2021},
	month = {apr},
	pages = {2217{\textendash}2224},
	doi = {10.1109/lra.2021.3059625},
	url = {https://doi.org/10.1109\%2Flra.2021.3059625},
	author = {Liang Zhang and Zexu Zhang and Roland Siegwart and Jen Jen Chung}
}
@conference {Zhang2021,
	title = {Task-Space Decomposed Motion Planning Framework for Multi-Robot Loco-Manipulation},
	booktitle = {2021 IEEE International Conference on Robotics and Automation (ICRA)},
	year = {2021},
	pages = {8158{\textendash}8164},
	publisher = {IEEE},
	organization = {IEEE},
	address = {Xi{\textquoteright}an, China},
	abstract = {This paper introduces a novel task-space decomposed motion planning framework for multi-robot simultaneous locomotion and manipulation. When several manipulators hold an object, closed-chain kinematic constraints are formed, and it will make the motion planning problems challenging by inducing lower-dimensional singularities. Unfortunately, the constrained manifold will be even more complicated when the manipulators are equipped with mobile bases. We address the problem by introducing a dual-resolution motion planning framework which utilizes a convex task region decomposition method, with each resolution tuned to efficient computation for their respective roles. Concretely, this dual-resolution approach enables a global planner to explore the low-dimensional decomposed task-space regions toward the goal, then a local planner computes a path in high-dimensional constrained configuration space. We demonstrate the proposed method in several simulations, where the robot team transports the object toward the goal in the obstacle-rich environments.},
	keywords = {Computational modeling, Conferences, Kinematics, Manifolds, Manipulators, Planning, System recovery},
	isbn = {978-1-7281-9078-5},
	issn = {1050-4729},
	doi = {10.1109/ICRA48506.2021.9560902},
	author = {Xiaoyu Zhang and Lei Yan and Tin Lun Lam and Sethu Vijayakumar}
}
@article {470,
	title = {Towards a Passive Self-Assembling Macroscale Multi-Robot System},
	journal = {IEEE Robotics and Automation Letters},
	volume = {6},
	year = {2021},
	pages = {7293-7300},
	doi = {10.1109/LRA.2021.3096748},
	author = {J{\'\i}lek, Martin and Somr, Michael and Kulich, Miroslav and Zeman, Jan}
}
@article {469,
	title = {Towards a Passive Self-Assembling Macroscale Multi-Robot System},
	journal = {IEEE Robotics and Automation Letters},
	volume = {6},
	year = {2021},
	pages = {7293-7300},
	doi = {10.1109/LRA.2021.3096748},
	author = {J{\'\i}lek, Martin and Somr, Michael and Kulich, Miroslav and Zeman, Jan and P{\v r}eu{\v c}il, Libor}
}
@conference {413,
	title = {AmphiLight: Direct Air-Water Communication with Laser Light},
	booktitle = {17th USENIX Symposium on Networked Systems Design and Implementation (NSDI 20)},
	year = {2020},
	publisher = {USENIX Association},
	organization = {USENIX Association},
	address = {Santa Clara, CA},
	isbn = {978-1-939133-13-7},
	url = {https://www.usenix.org/conference/nsdi20/presentation/carver},
	author = {Charles J. Carver and Zhao Tian and Hongyong Zhang and Kofi M. Odame and Quattrini~Li, Alberto and Xia Zhou}
}
@conference {493,
	title = {A Connectivity-Prediction Algorithm and its Application in Active Cooperative Localization for Multi-Robot Systems},
	booktitle = {2020 IEEE International Conference on Robotics and Automation (ICRA)},
	year = {2020},
	doi = {10.1109/ICRA40945.2020.9197083},
	author = {Zhang, Liang and Zhang, Zexu and Siegwart, Roland and Chung, Jen Jen}
}
@article {491,
	title = {Decentralised finite-time consensus for second-order multi-agent system under event-triggered strategy},
	journal = {IET Control Theory \& Applications},
	volume = {14},
	year = {2019},
	pages = {664{\textendash}673},
	author = {Zhang, Liang and Zhang, Zexu and Lawrance, Nicholas and Nieto, Juan and Siegwart, Roland}
}
@conference {492,
	title = {Optimized motion strategy for active target localization of mobile robots with time-varying connectivity},
	booktitle = {2019 International Symposium on Multi-Robot and Multi-Agent Systems (MRS)},
	year = {2019},
	publisher = {IEEE},
	organization = {IEEE},
	author = {Zhang, Liang and Zhang, Zexu and Siegwart, Roland and Chung, Jen Jen}
}
@article {97,
	title = {Decentralized rigidity maintenance control with range measurements for multi-robot systems},
	journal = {International Journal of Robotics Research},
	volume = {34},
	year = {2015},
	month = {01/2015},
	pages = {128},
	chapter = {105},
	abstract = {This work proposes a fully decentralized strategy for maintaining the formation rigidity of a multi-robot system using only range measurements, while still allowing the graph topology to change freely over time. In this direction, a first contribution of this work is an extension of rigidity theory to weighted frameworks and the rigidity eigenvalue, which when positive ensures the infinitesimal rigidity of the framework. We then propose a distributed algorithm for estimating a common relative position reference frame amongst a team of robots with only range measurements in addition to one agent endowed with the capability of measuring the bearing to two other agents. This first estimation step is embedded into a subsequent distributed algorithm for estimating the rigidity eigenvalue associated with the weighted framework. The estimate of the rigidity eigenvalue is finally used to generate a local control action for each agent that both maintains the rigidity property and enforces additional constraints such as collision avoidance and sensing/communication range limits and occlusions. As an additional feature of our approach, the communication and sensing links among the robots are also left free to change over time while preserving rigidity of the whole framework. The proposed scheme is then experimentally validated with a robotic testbed consisting of six quadrotor unmanned aerial vehicles operating in a cluttered environment. },
	keywords = {Decentralized control, distributed algorithm, distributed estimation, graph rigidity, multi-robot},
	doi = {10.1177/0278364914546173},
	url = {http://ijr.sagepub.com/content/34/1/105},
	author = {Daniel Zelazo and Antonio Franchi and Heinrich H. B{\"u}lthoff and Paolo Robuffo Giordano}
}
@conference {158,
	title = {Dynamic Load Distribution in Cooperative Manipulation Tasks},
	booktitle = {Proceedings of the 2015 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2015)},
	year = {2015},
	address = {Hamburg, Germany},
	doi = {http://dx.doi.org/10.1109/IROS.2015.7353699},
	author = {A. Zambelli and S. Erhart and L. Zaccarian and S. Hirche}
}
@article {216,
	title = {An Aerial-Ground Robotic System for Navigation and Obstacle Mapping in Large Outdoor Areas},
	journal = {Sensors},
	volume = {13},
	year = {2013},
	pages = {1247},
	abstract = {There are many outdoor robotic applications where a robot must reach a goal position or explore an area without previous knowledge of the environment around it. Additionally, other applications (like path planning) require the use of known maps or previous information of the environment. This work presents a system composed by a terrestrial and an aerial robot that cooperate and share sensor information in order to address those requirements. The ground robot is able to navigate in an unknown large environment aided by visual feedback from a camera on board the aerial robot. At the same time, the obstacles are mapped in real-time by putting together the information from the camera and the positioning system of the ground robot. A set of experiments were carried out with the purpose of verifying the system applicability. The experiments were performed in a simulation environment and outdoor with a medium-sized ground robot and a mini quad-rotor. The proposed robotic system shows outstanding results in simultaneous navigation and mapping applications in large outdoor environments.},
	issn = {1424-8220},
	doi = {10.3390/s130101247},
	url = {http://www.mdpi.com/1424-8220/13/1/1247},
	author = {Garz{\'o}n, Mario and Valente, Jo{\~a}o and Zapata, David and Barrientos, Antonio}
}
@inbook {170,
	title = {How Much Worth Is Coordination of Mobile Robots for Exploration in Search and Rescue?},
	booktitle = {RoboCup 2012: Robot Soccer World Cup XVI},
	series = {Lecture Notes in Computer Science},
	number = {7500},
	year = {2013},
	pages = {106{\textendash}117},
	publisher = {Springer},
	organization = {Springer},
	chapter = {How Much Worth Is Coordination of Mobile Robots for Exploration in Search and Rescue?},
	address = {Berlin, Heidelberg},
	abstract = {Exploration of unknown environments is an enabling task for several applications, including map building and search and rescue. It is widely recognized that several benefits can be derived from deploying multiple mobile robots in exploration, including increased robustness and efficiency. Two main issues of multirobot exploration are the exploration strategy employed to select the most convenient observation locations the robots should reach in a partially known environment and the coordination method employed to manage the interferences between the actions performed by robots. From the literature, it is difficult to assess the relative effects of these two issues on the system performance. In this paper, we contribute to filling this gap by studying a search and rescue setting in which different coordination methods and exploration strategies are implemented and their contributions to an efficient exploration of indoor environments are comparatively evaluated. Although preliminary, our experimental data lead to the following results: the role of exploration strategies dominates that of coordination methods in determining the performance of an exploring multirobot system in a highly structured indoor environment, while the situation is reversed in a less structured indoor environment.},
	keywords = {coordination, Exploration, multirobot, Search and Rescue},
	isbn = {978-3-642-39250-4},
	doi = {10.1007/978-3-642-39250-4_11},
	url = {http://dx.doi.org/10.1007/978-3-642-39250-4_11},
	author = {Amigoni, Francesco and Basilico, Nicola and Quattrini~Li, Alberto},
	editor = {Chen, Xiaoping and Stone, Peter and Sucar, Luis Enrique and Zant, Tijn}
}
@conference {98,
	title = {Rigidity Maintenance Control for Multi-Robot Systems},
	booktitle = {2012 Robotics: Science and Systems Conference},
	year = {2012},
	month = {07/2012},
	address = {Sydney, Australia},
	abstract = {Rigidity of formations in multi-robot systems is important for formation control, localization, and sensor fusion. This work proposes a rigidity maintenance gradient controller for a multi-agent robot team. To develop such a controller, we first provide an alternative characterization of the rigidity matrix and use that to introduce the novel concept of the rigidity eigenvalue. We provide a necessary and sufficient condition relating the positivity of the rigidity eigenvalue to the rigidity of the formation. The rigidity maintenance controller is based on the gradient of the rigidity eigenvalue with respect to each robot position. This gradient has a naturally distributed structure, and is thus amenable to a distributed implementation. Additional requirements such as obstacle and inter-agent collision avoidance, as well as typical constraints such as limited sensing/communication ranges and line-of-sight occlusions, are also explicitly considered. Finally, we present a simulation with a group of seven quadrotor UAVs to demonstrate and validate the theoretical results.},
	keywords = {Decentralized control, Formation control, Motion control of multiple robots, Multi-robot systems, Rigidity mainenance},
	author = {Daniel Zelazo and Antonio Franchi and Frank Allg{\"o}wer and Heinrich H. B{\"u}lthoff and Paolo Robuffo Giordano}
}
@conference {49,
	title = {A Mechanism for Dynamic Ride Sharing based on Parallel Auctions},
	booktitle = {Proc. of the 22th International Joint Conference on Artificial Intelligence (IJCAI)},
	year = {2011},
	address = {Barcelona, Spain},
	abstract = {Car pollution is one of the major causes of green- house emissions, and traffic congestion is rapidly becoming a social plague. Dynamic Ride Sharing (DRS) systems have the potential to mitigate this problem by computing plans for car drivers, e.g. commuters, allowing them to share their rides. Ex- isting efforts in DRS are suffering from the problem that participants are abandoning the system after repeatedly failing to get a shared ride. In this paper we present an incentive compatible DRS solution based on auctions. While existing DRS systems are mainly focusing on fixed assignments that minimize the totally travelled distance, the presented approach is adaptive to individual preferences of the participants. Furthermore, our system allows to tradeoff the minimization of Vehicle Kilometers Travelled (VKT) with the overall probability of successful ride-shares, which is an important feature when bootstrapping the system. To the best of our knowledge, we are the first to present a DRS solution based on auctions using a sealed-bid second price scheme.},
	isbn = {978-1-57735-516-8},
	author = {Kleiner, A. and Nebel, B. and Ziparo, V.}
}
