28 research outputs found
On the Positioning Performance of VDES R-Mode
Ships nowadays greatly rely on Global Navigation Satellite Systems (GNSSs) in order to deter-
mine their position. Since GNSS outages or jamming events do occur, there are efforts to reduce
the dependency on GNSS for maritime navigation. One such effort is called R-Mode (Ranging
Mode), and focuses on complementing maritime communication systems by a ranging compo-
nent to enable a vessel to determine its position. One of the systems to be extended by R-Mode
is the VHF Data Exchange System (VDES). The VDES communication system is currently in
standardization and offers 100 kHz of bandwidth in the maritime VHF band. It utilizes sin-
gle carrier modulation with pi/4-QPSK. The proposed R-Mode extension works by sending a
precisely timed known data sequence, so that time of arrival estimation allows determination
of the range. Using software defined radios (SDR), we implemented a test setup for VDES R-Mode with three base stations on land and one receiver located on a vessel. Using this setup,
we performed the first VDES R-Mode positioning trials on the Lake Ammer in Germany. By
determining the time of the arrival as well as the Doppler shift of the received signals we tracked
the vessels position with an Unscented Kalman Filter. The positioning accuracy performance
ranged to up to 22 m under favourable conditions. Crucial was the consideration of the Doppler
measurements to enhance tracking performance considerably
Integrated satellite-terrestrial connectivity for autonomous ships:Survey and future research directions
An autonomous vessel uses multiple different radio technologies such as satellites, mobile networks and dedicated narrowband systems, to connect to other ships, services, and the remote operations center (ROC). In-ship communication is mainly implemented with wired technologies but also wireless links can be used. In this survey paper, we provide a short overview of autonomous and remote-controlled systems. This paper reviews 5G-related standardization in the maritime domain, covering main use cases and both the role of autonomous ships and that of people onboard. We discuss the concept of a connectivity manager, an intelligent entity that manages complex set of technologies, integrating satellite and terrestrial technologies together, ensuring robust in-ship connections and ship-to-outside connections in any environment. This survey paper describes the architecture and functionalities of connectivity management required for an autonomous ship to be able to operate globally. As a specific case example, we have implemented a research environment consisting of ship simulators with connectivity components. Our simulation results on the effects of delays to collision avoidance confirm the role of reliable connectivity for safety. Finally, we outline future research directions for autonomous ship connectivity research, providing ideas for further work
Vessel Traffic Services, towards e-Navigation : the role of Oceanic VTS in global maritime surveillance
This thesis presents the study and analysis of the Vessel Traffic Services (VTS), from its origins to the present, with further evaluation of future trends. Examining the current trend in terms of technologies that are being applied in the maritime sector, the dissertation focuses on the future to draw a new paradigm. This envisages a scenario at a planetary level, following a single global traffic management system, which would create a model of the global VTS Operator. A new assignment is proposed, according to this third dimension, with Port VTS being the first level, the Coastal VTS second, and with the Oceanic VTS projected into the future, which is a substantial proposal. The foundation is based on EU projects, the most ambitious of which, currently underway, being Sea Traffic Management (STM), with a scope greater than Europe, and also on IALA VTS and ENAV Committee Working Groups, concerning the future of VTS.
The study includes the reference documentation from the IMO, in resolution format, and that of the IALA, under Standards, Recommendations and Guidelines. From the first recognition of the IMO to the present, the guidelines for VTS have undergone three updates, which are analysed and compared. VTS are considered aids to navigation, AtoN, which contribute to safety of life at sea, safety and efficiency of navigation and protection of the marine environment, and are linked to ship traffic activity. Both their attributions and the implementation of VTS centres have increased over time. In addition to this, the evolution of the tools used by the VTS is examined, from its earliest stages with only two pieces of equipment, the VHF radio, and the radar.
The VTS system began by looking at the air traffic model but, later, the maritime nature created necessary differentiation in terms of management and procedures. Digital technologies applied to the maritime sector take air traffic controllers’ models as a reference, and the current VTS Operator profession will acquire analogies, such as sharing route plans and checking digital inputs. This highly specialised profession is facing the challenges of satellite technology, global interconnection, and the arrival of Maritime Autonomous Surface Ships (MASS).
New technologies bring the possibility of sharing information and controlling traffic on a global scale, beyond the territorial sea, and this scenario will make standardisation increasingly necessary throughout the maritime sector. The identification of various models of traffic management, examination of systems operating specifically in the Spanish State and reflection on the diversity that prevails is also included. Based on fieldwork, the thesis determines that the future complexities that will emerge from maritime traffic will require exhaustive risk assessment and analysis. The challenges to be faced involve maritime communications via satellite and digital technology, in the context of ‘e-Navigation’ (coined by the IMO), which will provide emerging tools, such as VDES (next generation of AIS), and a planetary-scale information exchange framework for VTS worldwide.Aquesta tesi presenta l'estudi i l'anà lisi dels Serveis de Trà fic MarÃtim (VTS) des dels seus orÃgens fins al present, avaluant tendències futures. Examinant el corrent actual en referència a les tecnologies que s'estan aplicant al sector marÃtim, la tesi s’orienta al futur per delinear un nou paradigma. Un escenari a nivell planetari, que segueix un únic sistema de gestió de trà fic global, i que crearà un model d'operador VTS global. Es proposa una nova assignació acord a aquesta tercera dimensió, sent el VTS Port, el primer, el VTS Costaner, el segon, i es projecta a futur el VTS Oceà nic, que és la proposta substancial. La fundació es basa en projectes de la UE, on és el més ambiciós i actualment en marxa el Sea Traffic Management (STM), amb un abast superior a l'europeu i amb els grups de treball del Comitè VTS i ENAV de la IALA sobre l’esdevenidor del VTS. L’estudi inclou documentació de referència procedent de la IMO, en format resolucions; i la procedent de la IALA, sota està ndards, recomanacions i directrius. Des del primer reconeixement de la IMO fins ara, les directrius per als VTS han passat per tres actualitzacions, que s'analitzen i es comparen. Els VTS es consideren ajuts a la navegació, AtoN, que contribueixen a la seguretat de la vida humana al mar, la seguretat i l'eficiència de la navegació i la protecció del medi marà i estan vinculats a l'activitat del trà nsit de vaixells, i tant les seves atribucions com la implantació de centres VTS han augmentat al llarg de temps. A més a més d'això, s'examina l'evolució de les eines utilitzades pel VTS, des de les seves primeres etapes amb només dos equips, la rà dio VHF i el radar. El sistema VTS es va iniciar fixant-se en el model aeri, però posteriorment la naturalesa marÃtima els va diferenciar pel que fa a gestió i procediments. Les tecnologies digitals aplicades al sector marÃtim prenen com a referència models similars als controladors aeris, i l'actual professió d'Operador VTS assolirà analogies com ara compartir plans de ruta amb els vaixells i comprovació d'inputs digitals. Una professió altament especialitzada que s'enfronta als reptes de la tecnologia satel·lità ria, la interconnexió mundial i l'arribada dels vaixells marÃtims autònoms de superfÃcie (MASS). Les noves tecnologies porten la possibilitat de compartir informació i controlar el trà fic a escala global, més enllà del mar territorial, i aquest escenari farà que l'estandardització sigui cada cop més necessà ria a tot el sector marÃtim. Es considera la identificació de diversos models de gestió del trà fic, els sistemes que operen especÃficament a l'Estat espanyol i la reflexió sobre la diversitat que preval. A partir d'un treball de camp, la tesi determina que les complexitats que emergiran del trà fic marÃtim requeriran avaluació i anà lisi de riscos exhaustius. Els reptes que cal afrontar són aquells que inclouen les comunicacions marÃtimes via satèl·lit i la tecnologia digital en el context de l'e-Navegació, encunyat per la IMO, que proporcionaran eines emergents, com els VDES (propera generació de l’AIS), i un marc d’intercanvi d’informació a escala planetà ria per als VTS de tot el món.Postprint (published version
On jamming detection methods for satellite Internet of Things networks
Despite the fast growth of machine-type communications via satellite, the vulnerability of such networks to intentional interference and malicious jamming attacks is a raising concern. Specifically, in this paper, we address a class of jamming attacks in which the adversary uses the underlying knowledge of the satellite physical and access protocol to increase the jamming impact. In particular, we focused on a type of camouflage jamming attack (using publicly known preamble) to deceive the receiver, which rapidly leads to poor performance. Compared to conventional constant jamming attacks, these jamming strategies are known to be more effective and potentially more harmful to the targeted communication network. We analyze methods to detect such jamming attacks and provide examples of jamming detection techniques for the satellite Internet of Things (IoT) networks. Results indicate the effective performance of the jamming detection techniques for a variety of representative system parameters. More specifically, we introduce a simple (counting) jamming detection method along with numerical results for realistic system parameters, which confirms system design vulnerability as well as how the jammer may improve her strategy
Cognitive Vehicle Platooning in the Era of Automated Electric Transportation
Vehicle platooning is an important innovation in the automotive industry that aims at improving safety, mileage, efficiency, and the time needed to travel. This research focuses on the various aspects of vehicle platooning, one of the important aspects being analysis of different control strategies that lead to a stable and robust platoon. Safety of passengers being a very important consideration, the control design should be such that the controller remains robust under uncertain environments. As a part of the Department of Energy (DOE) project, this research also tries to show a demonstration of vehicle platooning using robots. In an automated highway scenario, a vehicle platoon can be thought of as a string of vehicles, following one another as a platoon. Being equipped by wireless communication capabilities, these vehicles communicate with one another to maintain their formation as a platoon, hence are cognitive.
Autonomous capable vehicles in tightly spaced, computer-controlled platoons will lead to savings in energy due to reduced aerodynamic forces, as well as increased passenger comfort since there will be no sudden accelerations or decelerations. Impacts in the occurrence of collisions, if any, will be very low. The greatest benefit obtained is, however, an increase in highway capacity, along with reduction in traffic congestion, pollution, and energy consumption.
Another aspect of this project is the automated electric transportation (AET). This aims at providing energy directly to vehicles from electric highways, thus reducing their energy consumption and CO2 emission. By eliminating the use of overhead wires, infrastructure can be upgraded by electrifying highways and providing energy on demand and in real time to moving vehicles via a wireless energy transfer phenomenon known as wireless inductive coupling. The work done in this research will help to gain an insight into vehicle platooning and the control system related to maintaining the vehicles in this formation