In particular, for a practical mobile robot team to perform such a task as that of carrying out a search and rescue mission in a disaster area, the network connectivity and localization have to be guaranteed even in an environment where the network infrastructure is destroyed or a Global Positioning System is unavailable. This paper proposes the new collective intelligence network management architecture of multiple mobile robots supporting seamless network connectivity and cooperative localization. The proposed architecture includes a resource manager that makes the robots move around and not disconnect from the network link by considering the strength of the network signal and link quality. The location manager in the architecture supports localizing robots seamlessly by finding the relative locations of the robots as they move from a global outdoor environment to a local indoor position. The proposed schemes assuring network connectivity and localization were validated through numerical simulations and applied to a search and rescue robot team.Keywords: Network connectivity and localization, seamless routing, cooperative localization, global positioning system, resource manager, location manager, CINeMA. Manuscript received Aug. 10, 2014; revised Dec. 11, 2014; accepted Dec. 26, 2014 I. IntroductionMultiple cooperative mobile robots performing search and rescue missions in disaster areas always require communication links to the human operator located at a remote station. However, the network infrastructure constructing the communication link is often destroyed in disaster areas; thus, a multi-hop mesh network connecting all robots and the operator station is needed for maintaining the link connectivity. In a multi-hop mesh network where the link environment is poor, the network configuration and routing of mobile robots are very important issues to guarantee the quality of service (QoS) of the communication link.Addressing these issues, J. Fink and others [1]-[2] proposed a k-connectivity method and resolved the end-to-end network connectivity problem using a probabilistic approach. In the DARPA LANdroids project [3], a self-configuring network scheme was developed, where the global network connectivity is maintained even in the case of a local connection failure. L. Sabattini and others [4]; S. Zickler and M. Veloso [5]; M.M. Zavlanos and others [6]; and N. Bezzo and others [7] analyzed the graph theoretical connectivity in mobile robot networks and developed optimization-based connectivity control methods. However, most previous approaches assumed that the network was connected within a fixed range of communication and that it relied on direct line-of-sight signals. Moreover, they used only the distance data between robots, which may not reflect the network connection information reasonably. In indoor or dynamic environments, a multi-path problem typically occurs; thus, the range information may become irregular. Therefore,
Abstract:Together with the GPS-based approach, geolocation through mobile communication networks is a key technology for location-based service. Since the Mobile WiMAX system is considered as a candidate for fourth-generation mobile systems, it is important to investigate its location capability. The geolocation of Mobile WiMAX can be realized when the preamble symbols in the down-link channel are appropriately used for a TDOA (Time-Difference-of-Arrival) approach. However, the cellular structure of Mobile WiMAX inevitably generates co-channel interference, and it is difficult for the mobile terminal to acquire distance measurements from multiple base stations. Therefore, for geolocation via multilateration using the Mobile WiMAX network, it is very important to increase hearability. This paper proposes a geolocation method for Mobile WiMAX which employs interference cancellation and preamble signal overlapping for the enhancement of hearability. A novel interference cancellation strategy for complex-valued Mobile WiMAX signals is presented which has an iterative structure. Simulation results show that the proposed geolocation method provides the user's position with an accuracy of less than 20 m through the Mobile WiMAX cellular network if there is no multi-path or NLOS (None-Line-of-Sight). Keywords: WiBro, geo-location, interference cancelation
Abstract:As flying robots are becoming popular, there are increased needs to use themforsuch purposes as parcel delivery, serving in restaurants, and stage performances. To control flying robots such as quad copters, localization is essential. In order to properly position flying robots, many techniques are in development, including IR (infra-red)-based systemswhich catch markers on a flying robot in order that it can position itself. However, this technique demonstrates only short coverage. Furthermore, localization from inertial sensors diverges as time passes. For this reason, this paper suggests a TWR (two-way ranging) based positioning technique. Despite the weaknesses in currently available TWR system, this paper suggests a self-positioning and outlier detection technique in order to provide reliable position information with a faster update rate. The self-positioning system sends a shorter message which reduces wireless traffic. By detecting and removing outlier measurements, a positioning result with better accuracy is acquired. Finally, this paper shows that the suggesting system detects outlierssequentially from less than half the number of anchors in localization system according to the degree of outlier in measurement and the noise level. By performing an outlier algorithm, better positioning accuracy is acquired as shown in the experimental result.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.