Enablers and Barriers for Truck Platooning in Norway: Case Studies on Infrastructure, Organization, Technology and Economics

Due to the intrinsic properties of the trucking industry, road freight is predicted to be an early adopter of highly automated vehicles on open roads. As a step towards fully driverless trucks, truck platooning is among the solutions which are forecast to materialize first. Leveraging the benefits of human supervision and automated driving, truck platooning refers to the idea of wirelessly connecting trucks, so they partake in coordinated convoying behind one another. Truck platoons are currently manned by a driver in the lead truck, who drives it manually. There are also safety drivers in the following trucks, who may be in charge of lateral control. The following trucks use automated distance-keeping systems to regulate speed, maintaining a preset distance to the preceding truck. Platooning with wireless communication may allow for short following distances since the reaction times of human drivers must no longer be accounted for. Hence, platooning may yield fuel savings and increased traffic safety. While all trucks in a platoon are required to be manned today, following trucks may eventually become unmanned. Then, the platoon could be controlled or monitored only by the lead driver, as digital systems could transfer his or her driving commands rearwards. This could allow for a doubling, or more, of per-driver freight volumes, which could reduce costs and alleviate driver shortages. Motivated by these prospects, platooning has been extensively researched in countries with favorable infrastructure, typically on multilane motorways. Limited research has considered truck platooning on typical Norwegian freight routes, which are predominantly two-way, two-lane rural roads, often characterized by difficult geometry, tunnels and ferry crossings. Moreover, previous research on organizational aspects of truck platooning is of limited relevance to the scatered industrial structure which characterizes Norway. Truck platooning depends on the simultaneous presence of at least two trucks to form a platoon, but it is unclear if the demand for road freight in Norway is sufficient to enable their organization at scale. Norway is also a small market for truck manufacturers, so they may not be willing to exert the effort to ensure that their systems work well on Norwegian roads. On the other hand, Norway is an affluent and technologically proactive nation with favorable regulation for testing automated driving systems. Still, fully driverless trucks on Norwegian roads seems far off, and it should be explored whether the prospects from platooning found in previous research may materialize in Norway. Local conditions may also give rise to novel motivations and unlock new avenues for implementing truck platooning. This doctoral thesis explores enablers and barriers for truck platooning, seeking to establish whether it constitutes a promising solution for road freight in Norway. Consequently, it is the first piece of work to publish peer-reviewed studies on the applicability of truck platooning in Norway from a transportation engineering perspective. The thesis may also serve as a stateof- the-art on higher-level automated trucks, and for automated vehicles generally, in the Norwegian context. Three separate case studies were undertaken as part of the doctoral work, namely a Stakeholder Study (i), a Field Study (ii), and an Industrial Study (iii). i. The Stakeholder Study explored the viability of truck platooning by interviewing professionals and practitioners in the transport sector. Novel deployment scenarios were outlined, including the use of ferry terminals for coordination, and envisioning truck platooning as a northward extension of the rail freight service. Interviewees stated that truck platooning will represent a mindset shift for carriers, as it requires them to cooperate. Truck platooning may be most feasible on long shipments which traverse high-standard roads with sufficient numbers of trucks to minimize the time spent waiting for a partner. Platooning may also warrant increased road maintenance spending, particularly if the value of transported goods were to be included in cost-benefit analyses. From an economic outlook, platooning may not be adopted until following trucks are unmanned and labor costs are unlocked. ii. The Field Study provided realistic, hands-on experience with truck platooning on a difficult rural road, using trucks with a prototype platooning system. The trucks were instrumented to study how the platoon behaved throughout the drive. The drivers were responsible for steering, while longitudinal control was automated. Most driving was uneventful, but the system was occasionally unable to keep the platoon stable in areas with sharp curves and rolling hills. In such situations, drivers occasionally had to intervene by pressing the brake and accelerator pedals. More advanced platooning systems with wireless communication should be tested, as these may overcome the aforementioned barriers, making it easier to draw conclusions on the operational viability of truck platooning in Norway. Truck manufacturers and data scientists should also be involved in piloting efforts to streamline data collection and analysis. iii. The Industrial Study complemented the prior studies by exploring two state-of-the-art trucking automation projects in closed areas. By interviewing project managers, the study reflected on the extent to which their experiences may suggest development paths for automated trucks on open roads. While the operations are impressive, the interviews revealed that both use-cases are highly customized, and hence simple, compared to the requirements for systems intended for public roads. Specifically, many technical issues had been circumvented using organizational and infrastructural means which are hard to undertake elsewhere. Based on experiences from the usecases, the study also discussed the removal of safety drivers. The case studies indicated that deployment of truck platooning requires efforts across four interwoven themes, namely conventional infrastructure, organization, enabling technology, and economics. Once the technology matures, truck platooning may be facilitated by certain aspects of Norwegian road infrastructure, while others will hinder deployment. Homogenous, high-standard roads seem most feasible, but freight corridors with such properties are limited in Norway, comprising a barrier. Conversely, many destinations in Norway have few alternative routes, causing natural funneling of trucks, which may support platooning arrangements. Ferry terminals, customs offices, and hubs along main roads, may comprise locations from where platoons can depart. High asset turnover among carriers may also expedite the uptake of new technology. Tunnels and winter conditions seem to pose operational challenges. Truck platooning still faces many unanswered questions, warranting further research. Until these are better understood, freight solutions should be explored which play to our strengths across all modalities, and which harmonize well with the Norwegian industrial structure.Sammendrag Tungtrafikken er spådd til å være tidlig ute med å ta i bruk automatiserte kjøretøy på offentlig veg, grunnet flere egenskaper som kjennetegner lastebilnæringen. Som et steg i utviklingen anses truck platooning som en av løsningene som forventes å dukke opp først. Konseptet søker å kombinere fordelene med menneskelig tilsyn og automatisert kjøring, og går ut på å trådløst koordinere og koble sammen grupper med lastebiler i kortesjer langs vegen. Truck platoons styres manuelt av en sjåfør i fremste lastebil, mens de påfølgende lastebilene er utstyrt med automatiserte systemer som opprettholder en forhåndsdefinert avstand til den forankjørende. Sjåførene i bakenforliggende lastebiler kan ha ansvar for svingebevegelser, men svingebevegelsene kan også være automatiserte, slik at sjåførene i praksis opptrer som sikkerhetssjåfører. I fremtiden kan de bakenforliggende lastebilene bli helt førerløse. Trådløs kommunikasjon kan overføre kjørekommandoene fra sjåføren i den fremste lastebilen, direkte til styringssystemet i de bakenforliggende lastebilene. Platooning kan dermed legge til rette for korte følgeavstander, siden reaksjonstidene til de bakenforliggende sjåførene ikke lenger må tas hensyn til. Bakenforliggende lastebiler kan dermed bli liggende i dragsuget til sin forankjørende lastebil, og dette kan utløse drivstoffbesparelser. Samtidig kan platooning med førerløse lastebiler bakover i kortesjen øke mengden last som hver sjåfør kan frakte. Med bakgrunn i disse mulighetene har truck platooning vært gjenstand for mye forskning i land med godt egnet infrastruktur, og mye testing har funnet sted på motorveger. Det finnes lite forskning om platooning på typiske norske godsruter, som hovedsakelig er landeveger, ofte preget av krøkkete geometri, lange tunneler, samt fjell- og ferjeoverganger. Tidligere betraktninger om organisatoriske aspekter ved truck platooning er dessuten lite relevant for vegsystemet og den spredte næringsstrukturen som kjennetegner landet vårt. Truck platooning krever tilstedeværelse av minst to lastebiler samtidig, men Norge er preget av forholdsvis lave trafikkvolumer. Dette kan gjøre det vanskelig å organisere truck platooning. Norge er dessuten et lite marked for lastebilprodusentene, slik at de ikke nødvendigvis er interesserte i å tilpasse sine kjøresystemer for norske forhold. På den annen side er Norge en velstående og teknologisk proaktiv nasjon med gunstig lovgivning for testing av automatiserte kjøresystemer. Til tross for dette vil det sannsynligvis ta lang tid før helt selvkjørende lastebiler er pålitelige nok til å begynne å trafikkere det norske vegnettet. Det bør derfor undersøkes om utsiktene for platooning identifisert i internasjonal litteratur kan oppnås i Norge. Kanskje kan også lokale forhold gi opphav til nye motivasjoner og muligheter for å ta i bruk platooning. Denne avhandlingen studerer truck platooning for å forstå i hvilken grad konseptet kan være aktuelt i landet vårt, og er den første som inneholder fagfellevurdert vegfaglig forskning om truck platooning i Norge. Den danner også et grunnlag for videre arbeid med innføring av automatiserte lastebiler og kjøretøy mer generelt, i norske forhold. Avhandlingen er basert på tre studier, en Interessentstudie (i), en Feltstudie (ii) og en Industristudie (iii): i. Interessentstudien utforsket hvorvidt truck platooning er egnet i Norge. Intervjuer ble avholdt med fagfolk som beskjeftiger seg med godstransport på veg. Fiktive, lokalt inspirerte scenarioer ble brukt for å engasjere deltakerne til å tenke over muligheter og barrierer. Informantene var enige om at truck platooning ville innebære store endringer for transportørene, hovedsakelig fordi det fordrer samarbeid for å fungere. Truck platooning ble vurdert til å være mest egnet på lange transporter på veier med høy standard, hvor det samtidig ferdes mange andre lastebiler. Deltakerne foreslo også at verdien som godstransporten står for bør hensyntas bedre i kost-nytte vurderinger i forbindelse med oppgraderinger av vegnettet. Dette kan også tenkes å gi bedre kår for platooning. Det vil sannsynligvis ikke være regningssvarende for transportørene å ta i bruk platooning før bakenforliggende lastebiler kan bli førerløse. ii. Feltstudien innebar testing av truck platooning på åpen veg med tre lastebiler, og høstet praktisk erfaring på en krevende vegstrekning i Nord-Norge. Lastebilene ble instrumentert for å studere hvordan platoonen oppførte seg underveis. Sjåførene styrte rattet selv, mens avstanden til forankjørende var automatisert. Mesteparten av kjøringen gikk rolig for seg, men platoonen slet med å holde seg samlet i områder med krappe horisontalkurver og kupert terreng. Dette medførte at førerne tidvis fant det nødvendig å gripe inn, hovedsakelig ved bruk av gass- og bremsepedaler. Systemer for platooning med trådløs overføring av kjørekommandoer bør testes. Slike systemer kan tenkes å overkomme flere av utfordringene som ble observert, og dermed gi et riktigere bilde av egnetheten til truck platooning i Norge. Lastebilprodusenter bør også være aktive bidragsytere i nye studier, for å forenkle uthenting og tolkning av data. iii. Industristudien gav en ny vinkling til arbeidet ved å besiktige to ulike bruksområder med automatiserte lastebiler på lukkede områder. Intervjuer med prosjektledere ble brukt for å kartlegge erfaringer fra de to prosjektene. Videre reflekterte studien over i hvilken grad erfaringene deres kan overføres til å ta i bruk automatiserte kjøretøy på offentlig veg. Selv om begge applikasjonene er å anse som nybrottsarbeid, kom det frem i intervjuene at de er relativt enkle, sammenlignet med kravene som vil møte automatiserte kjøresystemer på åpne veger. Eksempelvis ble tekniske utfordringer løst med organisatoriske endringer og fysiske tilpasninger som vanskelig lar seg overføre til veger som er åpne for allmenn ferdsel. Basert på erfaringer fra prosjektene diskuteres også betraktninger knyttet til fjerning av sikkerhetssjåfører. Innføring av platooning og automatisert kjøring vil kreve samordnet innsats på tvers av fire overlappende temaer. Disse var veginfrastruktur, organisering, muliggjørende teknologier og økonomi. Enkelte aspekter i Norge vil legge til rette for platooning, mens andre vil gjøre det krevende å ta i bruk. Veger med høy standard virker best egnet for platooning, men godsruter med slike egenskaper har begrenset utstrekning. Mange destinasjoner i Norge har få rutevalg, slik at lastebilene samles. Fergeterminaler, grenseoverganger og andre knutepunkter kan være egnede for koordinering. Hyppig utskifting av kjøretøy blant transportører kan også fremskynde bruken av platooning. Smale tunneler og vinterforhold ser ut til å gi driftsmessige utfordringer. Platooning er fremdeles forbundet med mange ubesvarte spørsmål, og det er behov for videre forskning for å sikre tilstrekkelig modenhet gjennom alle fire temaene. Det bør samtidig forskes på utvikling av helhetlige godsløsninger som underbygger våre styrker på tvers av alle modaliteter, og som harmonerer godt med norske forhold

Band gap alterations of graphitic carbon nitride for photoelectrochemical water splitting

En viktig energibærer for framtiden er hydrogengass, hvor utviklingen av effektive grønne produksjonsmetoder er nødvendig for å minimere miljøpåvirkningen av global oppvarming. En slik metode er fotoelektrolyse av vann, hvor halvlederen grafittisk karbonnitrid (g-C3N4) kan brukes som fotokatalysatoren i prosessen på grunn av sitt godt egnede båndgap for splitting av vann. Det er derimot ønskelig å redusere båndgapet slik at man kan utnytte mer av lyset og dermed øke utbyttet av hydrogengass sammenlignet med rent g-C3N4. Dette betyr at modifikasjoner av båndgapet gjennom doping kan forbedre utbyttet. I dette arbeidet demonstrerer vi at en høyere fotokatalytisk aktivitet blir oppnådd ved en sur pH for bordopet g-C3N4, på grunn av det reduserte båndgapet og dermed også høyere utnyttelse av lyset. Bordopet g-C3N4 ble syntetisert fra NaBH4 i en enkel oppvarmingsprosess og det resulterende båndgapet ble målt ved hjelp av diffus reflektansspektroskopi. Potensialene til båndkantene ved forskjellig pH ble funnet ved hjelp av Mott Schottky-analyse og undersøkelser av strømresponsen til halvlederen ved eksponering for Fe(CN)6^3 – /4 – redoksparet. Målreaksjonen som ble brukt til å måle den fotokatalytiske effektiviteten var oksidering av metyloransje ved belysning. Resultatene viste at bordopet g-C3N4 var rundt 2 % mer effektiv enn rent g-C3N4 ved en pH på 0,3, men rent g-C3N4 ble mer effektiv enn de bordopede prøvene for høyere pH-verdier. Dette var mest sannsynlig et resultat av løsnede båndkanter ved belysning for bordopet g-C3N4 sammenlignet med rent g-C3N4, som førte til en høyere drivkraft for oksideringen av metyloransje ved en pH på 0,3. Ved en økt pH var nok ikke effekten av løsnede båndkanter ved belysning nok til å kompensere for et økende katodisk potensial hos valensbåndene, som økte betydelig for de bordopede prøvene.An important energy carrier for the future is hydrogen gas, where the development of efficient green production methods is an important step in minimizing the environmental impact of global warming. One such green method is photoelectrolysis of water, where the semiconductor graphitic carbon nitride (g-C3N4) can be used as the photocatalyst in the process due to its suitable band gap for water splitting. However, it is desirable to reduce the band gap to exploit more of the available light, thus increasing the H2 yield of pristine g-C3N4. This means that modifications of the band gap through doping could help improve it. In this work we demonstrate that a higher photocatalytic activity was obtained at an acidic pH by doping g-C3N4 with boron, due to a reduced band gap and thus more utilization of the incoming light. Boron-doped g-C3N4 was synthesized in a simple heating process from NaBH4, and the resulting band gaps were measured using diffuse reflectance spectroscopy. The potentials of the band edges at different pH were found using the Mott Schottky analysis and by investigating the current response of the semiconductor when exposed to the Fe(CN)6^3 – /4 – redox couple. The target reaction used to measure the photocatalytic efficiency was the oxidation of methyl orange upon illumination. It was found that heavily boron-doped g-C3N4 proved to be roughly 2% more efficient than pristine g-C3N4 for a pH of 0.3, but pristine g-C3N4 proved more efficient than the boron-doped samples for an increased pH. This was likely due to a higher obtained driving force for the oxidation of methyl orange for boron-doped g-C3N4 compared to pristine g-C3N4 at a pH of 0.3, due to the effect of band edge unpinning upon illumination. At an increased pH, the effect of band edge unpinning upon illumination was likely not enough to compensate for the increasing cathodic potential of the valence bands, which was most prominent for the heavily boron-doped samples

The sea louse Caligus elongatus (Caligidae). Genetic variation and host use by its two genotypes

Caligus elongatus (Caligidae: Siphonostomatoida) is a common ectoparasite of fish in the north Atlantic. Unlike the salmon louse (Lepeophtheirus salmonis) which is specific to salmonids, C. elongatus infects more than 80 fish species and is considered an unspecific generalist parasite. It is registered on most common fish species in Norway, including farmed fish like Atlantic salmon (Salmo salar), Atlantic cod (Gadus morhua), Atlantic halibut (Hippoglossus hippoglossus) and lumpfish (Cyclopterus lumpus). Sudden infections with high intensities of adult C. elongatus on these farmed fish have been observed, without a preceding infection with chalimus larvae. Therefore, it is likely that these adult lice originate from wild fish outside the farms. We raise the question what role small-sized fish acting as intermediate hosts could play into the infections on farmed fish. It was recently discovered that C. elongatus actually consists of two (mtDNA) genotypes, genotype 1 and 2, which may be sibling species. This discovery necessitates renewed research into the ecology of the two C. elongatus variants, since much past work could have concerned a mix of these. Some recent studies provide indications of different host use, temporal occurrence and geographical distribution of the genotypes. The aim of the present work was to examine the genetic variation, morphology and aspects of the ecology of the C. elongatus genotypes. A likely intermediate host, the two-spotted goby (Gobiusculus flavescens), was sampled throughout a year to assess the infection dynamics of C. elongatus at a locality in western-Norway. Lice from these gobies, and additional ones from various sympatric hosts and from other locations from the north-east Atlantic, were genotyped. A novel primer assay based on the cytrochrome oxidase 1 (CO1) gene was tested. The CO1 gene was sequenced from 94 lice, and compared to reference sequences in GenBank. The prevalence of C. elongatus on two-spotted gobies peaked in May (10%) and October (5%). Nearly all were attached stages, mostly chalimi. Adults developing on the gobies must leave them to find another host for reproduction. It is demonstrated that this phenomenon can be responsible for high densities of free adult C. elongatus in the water. Such lice may also infect farmed fish. All juvenile lice found on two-spotted gobies throughout the year was genotype 2. Adults from Atlantic cod were mostly genotype 2, while all adult C. elongatus from farmed Atlantic salmon were genotype 1. Chalimi from lumpfish were genotype 1. Novel genotyping assays for genotyping with PCR readily distinguished the genotypes. We found 21 nucleotide positions defining the two genotypes based on the mtCO1 sequences. Morphometric comparison of major body proportions of copepodites and adult females from the two genotypes revealed significant differences: Genotype 1 C. elongatus were generally larger than genotype 2 and the cephalothorax shape of genotype 1 copepodids were more oblong than genotype 2. The present findings corroborate previous knowledge on the genotypes and their hosts, demonstrate the infection dynamics of genotype 2 on an intermediate host, and suggest morphological characters that should be examined further for their ability to distinguish these C. elongatus variants. The findings support the belief that the two genotypes could represent two species.Masteroppgave i fiskehelseFISK399MAMN-FIS

Depressurization of CO2 in pipes: Analysis of experiments and non-equilibrium flashing flow models

CO2 capture and storage is expected to play a vital role in reaching net zero emissions by 2050. In this context, large-scale CO2 pipeline transportation networks must be deployed. In order to perform safety analyses and ensure efficient operation of large-scale CO2 transportation systems it is key to predict the flow, in particular during depressurization events. This includes intentional depressurizations, e.g., the opening of a pressure relief valve, and accidental depressurizations, e.g., caused by a pipe fracture. High-capacity CO2 pipelines will be operated in the densephase region, meaning that the CO2 will boil during depressurization. This kind of boiling is denoted as flashing, and flashing often occurs delayed, i.e., at a lower pressure than the saturation pressure, out of equilibrium. The resulting pressure evolution and mass flow is highly dependent on the flashing process. Therefore, the focus of the present thesis is to gain more knowledge of this phenomenon through experiments and coupled thermo and fluid dynamics modeling. In this work, a series of full-bore pipe depressurization experiments were conducted and analyzed, physics-based models for the mass-transfer during flashing have been investigated, and novel numerical methods have been developed for the simulation of non-equilibrium two-phase flows. The effect of homogeneous and heterogeneous bubble nucleation on the maximum attained superheat in the experiments has been investigated. It is found that homogeneous nucleation determines the superheat at warm conditions, i.e., near the critical point, and heterogeneous nucleation dominates otherwise. Homogeneous nucleation can be modeled by classical nucleation theory. This theory is applied herein to account for delayed boiling for flow through orifices and nozzles, and to improve the fluid curve in the Battelle two-curve method for the assessment of pipeline designs with respect to running ductile fracture. It is found that the combination of the crevice model and bubble growth for heterogeneous nucleation can explain the attained superheat at colder temperatures. A main result from this work is a homogeneous flashing model (HFM) for flashing flows. The mass-transfer model in the HFM accounts for bubble nucleation, coalescence, breakup and growth. The key finding from the analysis of this model is that both homogeneous and heterogeneous nucleation must be included in flashing flow models to capture the flow behavior during depressurization at warm conditions, including the relevant operating region of CO2 transportation pipelines. The present findings for flashing flows are general and relevant for other industrial applications including refrigeration systems and water cooling for pressurized water (nuclear) reactors

Fatigue properties of adhesive joints in composite patch repair

This paper is a master thesis written at NTNU for the Co-Patch project. The Co-Patch project is an EU-funded consortium of 15 organizations from 8 different countries, developing a standard for composite patch repair of steel structures in fire hazard areas. The standard includes methods for dimensioning against delamination. This thesis looks at the fatigue properties in delamination of patches from their substrates. By testing Double Cantilever Beam and End-Notched Flexure specimens in fatigue loading, G-N curves were made for Mode I and Mode II fatigue fracture. This gives an indication of the lifetime of a patch given a specific cyclic load condition and a pre-existing crack. The longest cycle life recorded was 4.35E5 cycles at 104 J/m2 for Mode I and 1.23E5 cycles at 122 J/m2 for Mode II.Furthermore, a relation for crack propagation rate and energy release rate in Mode I was found for low cycle life estimation. From this relation, the crack front position may be estimated for a given set of cycles through calculations using Paris law. Based on the quasi-static data of a previous report, and the fatigue data found in this thesis, a numerical simulation procedure for crack propagation was proposed. Using direct cyclic fatigue analysis and Virtual Crack Closure Technique based on linear elastic fracture modelling, the crack propagation may be estimated for patches exposed to combined conditions, such as plane strain/plane stress and different fracture modes, as well as on advanced geometries. The procedure was validated as a viable simulation, but more work needs to be done on the model for accurate estimates.