Climate change is the focus of many oceanography and marine engineering researchers, with possible links between climate change and the carbon cycle in the Southern Ocean being considered. This type of investigation requires modern and cost-effective tools to conduct surveys and collect data from the ocean. The self-propelled unmanned surface vessel, the Liquid Robotics Wave Glider, was designed primarily as a marine research tool and offers several advantages over existing research vessels and other tools employed for data acquisition in the ocean. The main advantages are its robustness at sea, i.e. its ability to withstand extreme weather conditions, its propulsion energy source, which is the wave energy, and its customisable electronics payload. The inter-platform communication strategy of the Wave Glider inspired a few engineering questions, one of which is the focal point of this research: whether Low Power Wide Area Network (LPWAN) technology can be used to set up a local communication system enabling the collaboration of two or more Wave Gliders and reduce the cost, in terms of power and communication channels, involved in the communication with the Wave Glider platforms during missions. This research considers various LPWAN technologies available on the market and proposes LoRaWAN technology for the local communication system. LoRaWAN was selected as it presented a robust radio modulation and had growing support in the industry. In this research, a LoRa-based network of two nodes was developed, implemented and tested over the surface of the ocean. It was found that the system performs well over a distance of 1 km with both antennas having one end at the mean surface level of the sea. With the intention to increase the range of the platform and achieve a reliable and robust system, the research continued with the study of the influence of the surface waves on the proposed local communication system by exploring, firstly, the impact of seawater and, secondly, the wave height on signal transmission. The first study investigated the influence that the electromagnetic properties of seawater may have on the transmission of signals from one node to the second through simulations using the computational electromagnetic package FEKO. It revealed that, at the frequency of operation, which was 868 MHz, seawater reacted as a lossy conductor and reflected the signal upward, with negligible power penetrating the surface of the ocean. The subsequent study reviewed the statistical properties of the ocean surface waves in a sea of deep waters and proposed a relationship between the wind speed (or surface wave elevation), the antenna height, the distance separation between the two nodes and the probability of the presence of a line of sight (LoS) between the two nodes. This relationship quantifies the expected result that the probability of the LoS diminishes as the wind speed or the distance between the two nodes increases, whereas it improves with an increase in the antenna height. The last part of the research focused on initial works on sea state estimation using the lossless wave equation and Kalman Filter to provide 3D sea surface elevations that would be used to change to the probability of the LoS calculated previously in the research. Indeed, using the local communication to share the point-wise sea state data can be exploited to estimate the sea state over a rectangular region delimited to include these points. Sea state estimation is expected to enhance the joint navigation and coordination of the platforms and consequently, boost the probability of the LoS through the transmission at the crest of the waves. During the development of the Kalman Filter model, it was discovered that the sample time and the sample space significantly affect the performance and the stability of the discretised models. However, a carefully selected sampling time and sample space exhibited a stable system model. The results of the Kalman filtering were a realistic sea state estimate with a minimum error at the locations in the surrounding of the measurements.

This thesis demonstrates that a parametrically-modifiable Advanced Marine Vehicle Structural (AMVS) module (that can be integrated into a larger framework of marine vehicle analysis modules) enables stakeholders, as a group, to complete structurally feasible ship designs using the Set-Based Design (SBD) method. The SBD method allows stakeholders to identify and explore multiple solutions to stakeholder requirements and only eliminating the infeasible poorer solutions after all solutions are completely explored. SBD offers the and advantage over traditional design methods such as Waterfall and Spiral because traditional methods do not adequately explore the design space to determine if they are eliminating more optimal solutions in terms of cost, risk and performance. The fundamental focus for this thesis was on the development of a parametrically modifiable AMVS module using a low-fidelity structural analysis method implemented using a numerical 2D Finite Element Analysis (FEA) applied to the HY2-SWATH. To verify the AMVS module accuracy, a high-fidelity structural analysis was implemented in MAESTRO to analyze the reference marine vehicle model and provide a comparison baseline. To explore the design space, the AMVS module is written to be parametrically modified through input variables, effectively generating a new vessel structure when an input is changed. AMVS module is used to analyze an advanced marine vessel in its two operating modes: displacement and foil-borne. AMVS demonstrates the capability to explore the design space and evaluate the structural feasibility of the advance marine vehicle designs through consideration of the material, stiffener/girder dimensions, stiffener/girder arrangement, and machinery/equipment weights onboard. / Master of Science

This report is the result of the master thesis project in Industrial Design engineering (IDE), performed at Luleå University of Technology, by Erik Vesterlund. The task was to produce a conceptual belly boat design that enables individuals paralyzed in the lower extremities to use, propel, maneuver, assemble and use a belly boat. The initial stage included a pre-study of identifying and clarifying what the most common causes of paralyzation of the lower extremities originates from as well as finding the correct terms and what challenges they may include. It was discovered that there are many different causes and effects. Paraplegic are individuals who are unable to move, control or feel their legs depending on the severity of the injury. Quadriplegic individuals are unable to move, control or feel the entire of their body below their shoulders, depending on the severity of the injury. After the causes and effects were mapped, the challenges had to be identified. This was done through tests, interviews, literature studies and participant observations with individuals that are living with these types of injuries. Different problems and needs were mapped, and the most crucial to the usage of a belly boat was identified as the propelling and maneuvering of the craft. Safety aspects were also looked into and documented in order to ensure that the concept was safe for the users. Thereafter, a variety of methods were used in order to generate multiple ideas of how the identified problems and needs could be solved. The generated ideas were formulated and composed into complete solutions in the concept generating phase. The less good solutions were filtered out with the help of an evaluation matrix, and the good solutions were framed into different over-all concepts. Those were graded in a concept scoring matrix and composed into the final concept. The final concept fulfills the overall objectives and aims of the project, and also exceeds some of them, like allowing fully functional individuals to share the craft with Para- and quadriplegics, and without looking as equipment for individuals with disabilities. This broadens the market potential and increases the realization possibilities of a production, hence making the dream of assistance free wilderness adventures for Para- and quadriplegics all over the world, a reality. / Denna rapport är resultatet av ett examensarbete i Teknisk design, utfört vid Luleå tekniska universitet av Erik Vesterlund. Uppgiften var att ta fram en konceptuell båt design, som gör det möjligt för individer som är förlamade i de nedre extremiteterna att använda, driva, manöverera och använda en båt. I inledningsskedet genomfördes en förstudie för att identifiera och tydliggöra vad de vanligaste orsakerna till förlamning i de nedre extremiteterna, samt att ta reda på vilka utmaningar det omfattar. Det upptäcktes att det finns många olika orsaker och effekter. Paraplegi är individer som inte kan röra sig, kontrollera eller känna sina ben, beroende på hur allvarlig skadan är. Tetraplegi är individer som inte kan röra sig, styra eller känna hela sin kropp under sina axlar, beroende på hur allvarlig skadan är. Efter det att orsaker och effekter kartlagts, hade utmaningarna identifierats. Detta gjordes även genom tester, intervjuer, litteraturstudier och deltagande observationer med personer som lever med dessa typer av skador. Olika problem och behov kartlades, och den mest avgörande för användningen av en båt identifierades som framdrivning och manövrering av båten. Säkerhetsaspekter undersöktes och dokumenteras i syfte att säkerställa att konceptet var säkert för användarna. Därefter användes en mängd olika metoder för att generera flera idéer om hur de identifierade problemen och behoven skulle kunna lösas. De genererade idéer gestaltades i form av olika lösningar. De mindre bra lösningarna filtrerades bort, med hjälp av en utvärderingsmatris, och de goda lösningarna gestaltades i olika helhetskoncept. De graderades sedan i en konceptmatris och resulterade i det slutliga konceptet. Det slutgiltiga konceptet uppfyller det övergripande syftet och målen för projektet, och överträffar också några av dem, som att tillåta att fungerande individer delar båten med para- och quadriplegics, samt att konceptet inte ser ut som utrustning för personer med funktionshinder. Detta vidgar den potentiella marknaden och ökar realiseringsmöjligheterna, och bidrar därför till att drömmen om ett vildmarksäventyr för Para- och quadriplegics över hela världen, kan bli verklighet.