{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,17]],"date-time":"2025-10-17T13:59:15Z","timestamp":1760709555149,"version":"build-2065373602"},"reference-count":40,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2018,3,20]],"date-time":"2018-03-20T00:00:00Z","timestamp":1521504000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Spanish Ministerio de Econom\u00eda y Competitividad","award":["DPI2015-69376-R"],"award-info":[{"award-number":["DPI2015-69376-R"]}]},{"name":"Vicerrectorado de Pol\u00edtica Cient\u00edfica, Universidad de Zaragoza","award":["JIUZ-2017-TEC-01"],"award-info":[{"award-number":["JIUZ-2017-TEC-01"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Multi-robot teams composed of ground and aerial vehicles have gained attention during the last few years. We present a scenario where both types of robots must monitor the same area from different view points. In this paper, we propose two Lloyd-based tracking strategies to allow the ground robots (agents) to follow the aerial ones (targets), keeping the connectivity between the agents. The first strategy establishes density functions on the environment so that the targets acquire more importance than other zones, while the second one iteratively modifies the virtual limits of the working area depending on the positions of the targets. We consider the connectivity maintenance due to the fact that coverage tasks tend to spread the agents as much as possible, which is addressed by restricting their motions so that they keep the links of a minimum spanning tree of the communication graph. We provide a thorough parametric study of the performance of the proposed strategies under several simulated scenarios. In addition, the methods are implemented and tested using realistic robotic simulation environments and real experiments.<\/jats:p>","DOI":"10.3390\/s18030927","type":"journal-article","created":{"date-parts":[[2018,3,20]],"date-time":"2018-03-20T15:59:39Z","timestamp":1521561579000},"page":"927","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Simultaneous Deployment and Tracking Multi-Robot Strategies with Connectivity Maintenance"],"prefix":"10.3390","volume":"18","author":[{"given":"Javier","family":"Tard\u00f3s","sequence":"first","affiliation":[{"name":"Instituto de Investigaci\u00f3n en Ingenier\u00eda de Arag\u00f3n, Universidad de Zaragoza, 50018 Zaragoza, Spain"}]},{"given":"Rosario","family":"Aragues","sequence":"additional","affiliation":[{"name":"Instituto de Investigaci\u00f3n en Ingenier\u00eda de Arag\u00f3n, Universidad de Zaragoza, 50018 Zaragoza, Spain"}]},{"given":"Carlos","family":"Sag\u00fc\u00e9s","sequence":"additional","affiliation":[{"name":"Instituto de Investigaci\u00f3n en Ingenier\u00eda de Arag\u00f3n, Universidad de Zaragoza, 50018 Zaragoza, Spain"}]},{"given":"Carlos","family":"Rubio","sequence":"additional","affiliation":[{"name":"Instituto de Investigaci\u00f3n en Ingenier\u00eda de Arag\u00f3n, Universidad de Zaragoza, 50018 Zaragoza, Spain"}]}],"member":"1968","published-online":{"date-parts":[[2018,3,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1133","DOI":"10.1109\/TRO.2016.2593454","article-title":"Ground and Aerial Mutual Localization Using Anonymous Relative-Bearing Measurements","volume":"32","author":"Stegagno","year":"2016","journal-title":"IEEE Trans. Robot."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"128","DOI":"10.1109\/TRO.2014.2380593","article-title":"Multirobot Rendezvous Planning for Recharging in Persistent Tasks","volume":"31","author":"Mathew","year":"2015","journal-title":"IEEE Trans. Robot."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Rold\u00e1n, J.J., Garcia-Aunon, P., Garz\u00f3n, M., de Le\u00f3n, J., del Cerro, J., and Barrientos, A. (2016). Heterogeneous Multi-Robot System for Mapping Environmental Variables of Greenhouses. Sensors, 16.","DOI":"10.3390\/s16071018"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Deusdado, P., Guedes, M., Silva, A., Marques, F., Pinto, E., Rodrigues, P., Louren\u00e7o, A., Mendon\u00e7a, R., Santana, P., and Corisco, J. (2016). Sediment Sampling in Estuarine Mudflats with an Aerial-Ground Robotic Team. Sensors, 16.","DOI":"10.3390\/s16091461"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1299","DOI":"10.1016\/j.automatica.2009.01.018","article-title":"Distributed discrete-time coordinated tracking with a time-varying reference state and limited communication","volume":"45","author":"Cao","year":"2009","journal-title":"Automatica"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1016\/j.automatica.2015.11.005","article-title":"Distributed finite-time tracking of multiple non-identical second-order nonlinear systems with settling time estimation","volume":"64","author":"Zhao","year":"2016","journal-title":"Automatica"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1213","DOI":"10.1109\/TRO.2008.2002313","article-title":"Connectedness Preserving Distributed Swarm Aggregation for Multiple Kinematic Robots","volume":"24","author":"Dimarogonas","year":"2008","journal-title":"IEEE Trans. Robot."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Leccese, A., Gasparri, A., Priolo, A., Oriolo, G., and Ulivi, G. (2013, January 6\u201310). A Swarm Aggregation Algorithm based on Local Interaction with Actuator Saturations and Integrated Obstacle Avoidance. Proceedings of the 2013 IEEE International Conference on Robotics and Automation (ICRA), Karlsruhe, Germany.","DOI":"10.1109\/ICRA.2013.6630823"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1586","DOI":"10.1016\/j.automatica.2012.05.071","article-title":"Distributed containment control with multiple stationary or dynamic leaders in fixed and switching directed networks","volume":"48","author":"Cao","year":"2012","journal-title":"Automatica"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/j.automatica.2015.12.016","article-title":"Leader\u2013follower containment control over directed random graphs","volume":"66","author":"Kan","year":"2016","journal-title":"Automatica"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"663","DOI":"10.1109\/TAC.2011.2164733","article-title":"Connectivity and Set Tracking of Multi-Agent Systems Guided by Multiple Moving Leaders","volume":"57","author":"Shi","year":"2012","journal-title":"IEEE Trans. Autom. Control"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"550","DOI":"10.1109\/TRO.2013.2293836","article-title":"Control of a Group of Mobile Robots Based on Formation Abstraction and Decentralized Locational Optimization","volume":"30","author":"Yoshida","year":"2014","journal-title":"IEEE Trans. Robot."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1018","DOI":"10.1109\/TRO.2015.2452774","article-title":"Implementation of Coordinated Complex Dynamic Behaviors in Multirobot Systems","volume":"31","author":"Sabattini","year":"2015","journal-title":"IEEE Trans. Robot."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1016\/j.automatica.2017.06.022","article-title":"Pursuing an evader through cooperative relaying in multi-agent surveillance networks","volume":"83","author":"Du","year":"2017","journal-title":"Automatica"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Moon, S., and Frew, E.W. (2017, January 13\u201316). Distributed Cooperative Control for Joint Optimization of Sensor Coverage and Target Tracking. Proceedings of the 2017 International Conference on Unmanned Aircraft Systems (ICUAS), Miami, FL, USA.","DOI":"10.1109\/ICUAS.2017.7991457"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1109\/TRA.2004.824698","article-title":"Coverage Control for Mobile Sensing Networks","volume":"20","author":"Karatas","year":"2004","journal-title":"IEEE Trans. Robot. Autom."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2199","DOI":"10.1109\/TAC.2007.908301","article-title":"On synchronous robotic networks\u2014Part I: Models, tasks, and complexity","volume":"52","author":"Bullo","year":"2007","journal-title":"IEEE Trans. Autom. Control"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2214","DOI":"10.1109\/TAC.2007.908304","article-title":"On synchronous robotic networks\u2014Part II: Time Complexity of Rendezvous and Deployment Algorithms","volume":"52","author":"Bullo","year":"2007","journal-title":"IEEE Trans. Autom. Control"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1077","DOI":"10.1016\/j.automatica.2012.03.009","article-title":"Self-Triggered Coordination of Robotic Networks for Optimal Deployment","volume":"48","author":"Nowzari","year":"2012","journal-title":"Automatica"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1109\/TCNS.2015.2428304","article-title":"Dynamic Partitioning and Coverage Control With Asynchronous One-to-Base-Station Communication","volume":"3","author":"Patel","year":"2016","journal-title":"IEEE Trans. Control Netw. Syst."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"691","DOI":"10.1051\/cocv:2005024","article-title":"Spatially-distributed coverage optimization and control with limited-range interactions","volume":"11","author":"Bullo","year":"2005","journal-title":"ESAIM Control Optim. Calc. Var."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1177\/0278364916688103","article-title":"Adapting to sensing and actuation variations in multi-robot coverage","volume":"36","author":"Pierson","year":"2017","journal-title":"Int. J. Robot. Res."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"209","DOI":"10.1016\/j.automatica.2015.10.035","article-title":"Distributed communication-aware coverage control by mobile sensor networks","volume":"63","author":"Kantaros","year":"2016","journal-title":"Automatica"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Li, W., and Liu, Y. (June, January 29). Dynamic Coverage Control for Mobile Robot Network with Limited and Nonidentical Sensory Ranges. Proceedings of the 2017 IEEE International Conference on Robotics and Automation (ICRA), Singapore.","DOI":"10.1109\/ICRA.2017.7989095"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1109\/TRO.2015.2397771","article-title":"Multirobot Control Using Time-Varying Density Functions","volume":"31","author":"Lee","year":"2015","journal-title":"IEEE Trans. Robot."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"700","DOI":"10.1109\/TRO.2017.2664883","article-title":"Bounded Control Law for Global Connectivity Maintenance in Cooperative Multirobot Systems","volume":"33","author":"Gasparri","year":"2017","journal-title":"IEEE Trans. Robot."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1887","DOI":"10.1137\/16M1077064","article-title":"Robustness and Invariance of Connectivity Maintenance Control for Multiagent Systems","volume":"55","author":"Boskos","year":"2017","journal-title":"SIAM J. Control Optim."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1525","DOI":"10.1109\/JPROC.2011.2157884","article-title":"Graph-Theoretic Connectivity Control of Mobile Robot Networks","volume":"99","author":"Zavlanos","year":"2011","journal-title":"Proc. IEEE"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Li, X., and Xi, Y. (2009, January 15\u201318). Distributed Cooperative Coverage and Connectivity Maineinance for Mobile Sensing Devices. Proceedings of the 2009 Joint 48th IEEE Conference on Decision and Control, Shanghai, China.","DOI":"10.1109\/CDC.2009.5399562"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"2588","DOI":"10.1137\/090753243","article-title":"Distributed Tree Rearrangements for Reachability and Robust Connectivity","volume":"50","author":"Schuresko","year":"2012","journal-title":"SIAM J. Control Optim."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Aranda, M., Aragues, R., L\u00f3pez-Nicol\u00e1s, G., and Sag\u00fc\u00e9s, C. (2016, January 6\u20138). Connectivity-Preserving Formation Stabilization of Unicycles in Local Coordinates Using Minimum Spanning Tree. Proceedings of the 2016 American Control Conference (ACC), Boston, MA, USA.","DOI":"10.1109\/ACC.2016.7525207"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Aragues, R., Sag\u00fc\u00e9s, C., and Mezouar, Y. (2014, January 24\u201327). Triggered Minimum Spanning Tree for Distributed Coverage with Connectivity Maintenance. Proceedings of the 2014 European Control Conference (ECC), Strasbourg, France.","DOI":"10.1109\/ECC.2014.6862288"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Soleymani, T., Garone, E., and Dorigo, M. (2015, January 1\u20133). Distributed Constrained Connectivity Control for Proximity Networks based on a Receding Horizon Scheme. Proceedings of the 2015 American Control Conference (ACC), Chicago, IL, USA.","DOI":"10.1109\/ACC.2015.7170924"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"365","DOI":"10.3182\/20090909-4-JP-2010.00063","article-title":"A distributed minimum restrictive connectivity maintenance algorithm","volume":"42","author":"Wagenpfeil","year":"2009","journal-title":"IFAC Proc. Vol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"729","DOI":"10.1007\/s10514-015-9491-7","article-title":"Multi-robot target detection and tracking: Taxonomy and survey","volume":"40","author":"Robin","year":"2016","journal-title":"Auton. Robots"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1145\/357195.357200","article-title":"A Distributed Algorithm for Minimum-Weight Spanning Trees","volume":"5","author":"Gallager","year":"1983","journal-title":"ACM Trans. Progr. Lang. Syst."},{"key":"ref_37","unstructured":"Cao, M., and Hadjicostis, C. (2003). Distributed Algorithms for Voronoi Diagrams and Application in Ad-hoc Networks, UIUC Coordinated Science Laboratory. Tech. Rep. UILU-ENG-03-2222, DC-210."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"818","DOI":"10.1109\/70.795787","article-title":"Distributed Memoryless Point Convergence Algorithm for Mobile Robots with Limited Visibility","volume":"15","author":"Ando","year":"1999","journal-title":"IEEE Trans. Robot. Autom."},{"key":"ref_39","unstructured":"(2018, March 20). Google Drive Folder. Available online: https:\/\/drive.google.com\/open?id=1WkSWwcgT32OVk6Z0jX6m9hqubFKV3kmk."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"2280","DOI":"10.1016\/j.patcog.2014.01.005","article-title":"Automatic generation and detection of highly reliable fiducial markers under occlusion","volume":"47","year":"2014","journal-title":"Pattern Recognit."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/3\/927\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T14:57:49Z","timestamp":1760194669000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/3\/927"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,3,20]]},"references-count":40,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2018,3]]}},"alternative-id":["s18030927"],"URL":"https:\/\/doi.org\/10.3390\/s18030927","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2018,3,20]]}}}