Auswahl der wissenschaftlichen Literatur zum Thema „Articulated measurement arms“

Kinematic parameters identification and compensation are effective ways to improve the accuracy of articulated arm coordinate measuring machines (AACMMs) and robotic arms without increasing the cost of hardware. Generally, kinematic parameters identification methods based on standard references are relatively high in accuracy but time-consuming and not suitable for industrial sites, while kinematic parameters identification methods based on repeatability are flexible and easy to implement but lack reliability in accuracy. A novel kinematic parameters identification method for AACMMs using repeatability and scaling factor is proposed in this paper, which combines the advantages of methods based on both standard references and repeatability. Through theoretical analysis and numerical simulations, we found that the commonly used single-point-repeatability-based identification method has problems in identifying the length parameters, which is due to that high repeatability cannot guarantee the accuracy of the kinematic parameters and the measurement accuracy of the AACMM. Further analysis showed that the error of the length parameters is determined by a scaling factor which can be used to remove the error of length parameters. Therefore, a two-step novel kinematic parameters identification method for the AACMMs using repeatability and scaling factor was proposed to get accurate parameters with convenient operation. Experimental studies showed the effectiveness of the proposed identification method, which indicated that 93% more error in spatial length can be decreased comparing to the traditional method of repeatability-based identification.

Portable Measuring Arms or Articulated Arm Coordinate Measuring Machines (AACMMs) unique characteristics bring flexibility to the inspection task and allow outside laboratory measurements. However, still a few works study their metrological behavior, uncertainty or assessment. In fact, AACMM assessment involves time consuming and expensive processes mainly inherited from CMM field. A virtual circle gauge similar to ball bars and a methodology based on international standards are proposed in order to simplify the evaluation test. Additionally, two metrological laboratories have evaluated different AACMM models with this gauge. Also, two gauge lengths (distance between circles) have be included in this study. Results have proved that virtual circle gauges are suitable to evaluate AACMMs and tested the influence of distance between virtual circles.

Computational models of the musculoskeletal system are scientific tools used to study human movement, quantify the effects of injury and disease, plan surgical interventions, or control realistic high-dimensional articulated prosthetic limbs. If the models are sufficiently accurate, they may embed complex relationships within the sensorimotor system. These potential benefits are limited by the challenge of implementing fast and accurate musculoskeletal computations. A typical hand muscle spans over 3 degrees of freedom (DOF), wrapping over complex geometrical constraints that change its moment arms and lead to complex posture-dependent variation in torque generation. Here, we report a method to accurately and efficiently calculate musculotendon length and moment arms across all physiological postures of the forearm muscles that actuate the hand and wrist. Then, we use this model to test the hypothesis that the functional similarities of muscle actions are embedded in muscle structure. The posture dependent muscle geometry, moment arms and lengths of modeled muscles were captured using autogenerating polynomials that expanded their optimal selection of terms using information measurements. The iterative process approximated 33 musculotendon actuators, each spanning up to 6 DOFs in an 18 DOF model of the human arm and hand, defined over the full physiological range of motion. Using these polynomials, the entire forearm anatomy could be computed in <10 μs, which is far better than what is required for real-time performance, and with low errors in moment arms (below 5%) and lengths (below 0.4%). Moreover, we demonstrate that the number of elements in these autogenerating polynomials does not increase exponentially with increasing muscle complexity; complexity increases linearly instead. Dimensionality reduction using the polynomial terms alone resulted in clusters comprised of muscles with similar functions, indicating the high accuracy of approximating models. We propose that this novel method of describing musculoskeletal biomechanics might further improve the applications of detailed and scalable models to describe human movement.

The discussion emphasizes the peculiarity and individuality of both the shape and style of Dalmatian hexaconchs. Together with the rotunda of Holy Trinity at Zadar, they surely represent the most original architectural creation of early medieval Dalmatia and its specific cultural milieu which grew from a twofold tradition in a true symbiosis of the European East and West in the Adriatic area. Their mutual interdependence in Dalmatia was articulated through the individual shapes of religious architecture. These hexaconchs are a form specific to only the innermost part of Dalmatia, centred on the area between Zadar and Split, and deep into the hinterland of these towns, which corresponded to the Croatian principality.Certainly, buildings as special as this had their own original matrix - an individual spatial composition and a specific structure which formed their body. Without this, the hexaconchs would not have possessed the originality which has been observed by all the scholars who have written about them. Indeed, they have their own shape and style. By analyzing and interpreting the legacy of Dalmatian religious architecture, it seems plausible to assume that the early Christian baptistery of Zadar Cathedral may have served as a model not only for their hexaconchal shape and spatial structure but also for their dimensions and proportions. In the regional architecture prior to the period when the hexaconchs were built, no other building, aside from the Zadar baptistery, had such a shape and such a compositional compatibility with the hexaconchs; the very structure and measurements of their interior space. However, the architectural style of the hexaconchs, which display pilaster strips on their exteriors, and their vocabulary of pre-Romanesque language find their parallels on the monumental rotunda of Holy Trinity - a chapel adjacent to the baptistery itself, located nearby in the same episcopal complex - more than on any other late Antique or early medieval building both in the immediate region and in the whole Adriatic basin. For this reason, the search for the origin of the shape and style of Dalmatian hexaconchs leads us to Zadar and it is no wonder that almost every scholar who has studied this group of buildings has pointed to this fact. Their geographical distribution also witnesses this influence in its own way: two hexaconchs can be found at Zadar, while four or even five more are located in the wider Zadar area, adding up to seven out of the ten Dalmatian hexaconchs in total.This number implies that this group of rotundas, being characteristic for a specific period in Dalmatia, was created in a relatively short period of time. Moreover, it points to the building and carving workshops which, drawing upon the same source model, constructed the hexaconchs and provided them with stone liturgical furnnishings. In particular, further indications can be found in the production of the socalled Benedictine carving workshop, probably located at Zadar, a workshop from the time of Prince Trpimir which produced the furnishings for the hexaconchs at Pridraga and Kašić, and the carving workshop from Trogir which was responsible for the carvings at Trogir and Brnaze. All of these, with regard to the hexaconchs, testify to predominantly early ninth-century production, and represent the main argument for the dating of these interesting Dalmatian rotundas to the same time. Apart from their original pre-Romanesque shape, the majority of the free-standing hexaconchal rotundas were provided with early Romanesque additions during the course of time, and these additions turned these hexaconchs into small complexes of sorts. Vestibules created in this period suggest two possiblities: according to one, the vestibules added in this manner were actually a kind of exterior crypt, spaces where sarcophagi could be housed, and according to the other, some of these vestibules were also provided with bell-towers built on top of them. The latter possibility is implied by the dispositions of the suggested bell-towers and the strength of the supporting substructions (e.g. the Stomorica church at Zadar or the hexaconch at Kašić), but also by the stylistic elements which point to the early Romanesque, and architectural details, the function of which indicates a bell-tower (e.g. impost capitals of the Stomorica church or St Chrysogonus at Zadar, and an octogonal colonette from Kašić).

I spent more than two years in Bangladesh and lived through several incarnations—as a volunteer for aid organisations, an expatriate socialite, a bidesi (foreigner) trying to live sodesi (locally)—before becoming an ethnographer and, simultaneously, a lover and fighter of my adopted country. During the winter of my second lifetime I was sexually assaulted and at the beginning of my third lifetime, I recounted the experience at an academic conference in Dhaka. Smitten by the possibility that personal revelation could overcome cross-cultural barriers, I read A Night Out to compel others to sympathise and share, perhaps even loosen the somewhat restricted discussion of sexual intimidation in Bangladesh. Yet the response to A Night Out was quiet, absorbed by the static of courtesy, and taught me that disclosure alone cannot transcend differences to reach a space of mutual understanding. Later, when I posted A Night Out online, I observed the continued and changing capacity of revelation to evoke responses from people across genders and cultures. This article argues that the impact of revelation, although difficult to quantify, is never static and depends significantly on context: first, by describing autoethnography, a way of writing about other cultures that connects the "autobiographical and personal to the cultural, social and political" (Ellis xix), in the "Before" section to give background to A Night Out; secondly, the "After" section considers the various responses to the story and discusses it as "both a process and a product" of cultural research (xix). Before A Night Out Switching lives between Australia and Bangladesh has shown me the value of cultural research that deconstructs traditional conceptions of the "Western" and "Eastern" worlds. In terms of the representations of women, those in the East are too often prescribed the characteristics of ignorance, poverty, illiteracy, domesticity, maternity, and victimization, while the Western woman is depicted as modern, educated, in control of her body and sexuality (Gandhi 86). As a researcher, ultimately, of the life stories of Bangladeshi women, I sought to decrease the misconceptions surrounding those who were, like me, never only "West" or "East", influenced but never solely defined by their culture. Autoethnography is a method of cultural research that makes connections between "individual experience and social processes" in ways that emphasise the essential falsity of cultural categories (Sparkes 217). To transcend these boundaries of people, place and time, autoethnographers make use of narrative, believing it to be "the best way to understand the human experience" because it is "the way humans understand their own lives" (Richardson 218). As a writer, I likewise believe that narrative provides a way to make sense of or negotiate one's place in relation to any space or group of people. In particular, telling personal stories "bears fruit" of "reaching out to others," provoking their own stories and emotional responses, thereby becoming an effective cultural research method (Four Arrows 106). I remember my admiration for the Bangladeshi writer Shabnam Nadiya, who in Woman Alone describes her isolating experiences of sexual molestation as a girl and, later, the realisation via the writing of Taslima Nasrin that "it happened everywhere, everyday ... to anyone" (2008). For Nadiya, self-reflexivity created a "bridge" between the interior practise of reading and the exterior "everyday lived life" of communal experience and identity (2008). While connections on such an intimate scale may be difficult or unwelcome, making them is significant as "the process of revolution itself" (Ware 239). Inspired by Nadiya to write a piece with enough emotional power to reach over the public space of the conference room, my revelation concerned one of my own experiences as a woman in Bangladesh. A Night Out I was never afraid of my city at night. The time I liked Dhaka best was when the day wore down to dusk and the sky looked like it had been brushed clean. When I lived near Dhanmondi Lake I would walk through the drab hues of the surrounding park with its concrete paths and dusty trees that stretched their reflections across the pond-green water. The park was always crowded with raucous wallahs (vendors) and power walking women in bright dresses, yet even so I was the focus of attention, haunted by exclamations of "Koto lomba!" (How tall!) until my shadows became longer than myself in the quartzy light, and I was not so noticeable. When I moved to the Newmarket area I would spend the twilight hours sitting barefoot on my balcony in a voluminous housedress, watching Dhaka's night stage. Children played games on the rooftop of the lower apartment block opposite, women unhooked lines of fresh laundry and groups of friends would chat or play guitar. Even when the evening azan growled from the megaphones of nearby mosques there was activity on the street below, figures moving under the marigold glare of the sodium streetlights or, in winter, stretching nets across the street for badminton matches. Rickshawallahs rang their bells to the call of the crows and there was always an obnoxious motorist laying into his car horn. I felt more a part of my neighbourhood at this distance than when I became, eight floors down, the all-too-visible spectacle of the only foreigner in the district. The flat, my only source of solitude in Dhaka, was in a peaceful building set at the end of a road that turned three corners before coming to a blind halt. Walking its length day and night to reach the main thoroughfare, I got to know the road well. A few old bungalows remained, with comfortably decaying verandas behind wrought-ironwork and the shade of banana trees. Past the first corner the road became an entry for Dhaka College and the high school opposite; houses gave way to walls papered with adverts, a cluster of municipal bins surrounded by litter and wooden shacks that served cha (tea) and fried snacks. I was on friendly terms with the grey-haired wallah who stalked the area daily with his vegetable cart and one betel-chewing woman who sorted the neighbourhood rubbish. Once I neared the college attention from the chawallahs and students became more harassing than friendly, but I continued to walk to and from my house and most of the time, I walked alone. When solitude turns oppressive, the solution is to open all windows and doors and let air and friends in. One evening I invited Mia and Farad, both journalists and wine-drinkers, who arrived before sunset and stayed almost til midnight. We all knew the later it became the harder it would be for Mia to reach her home across the city. A call to one of the less dodgy cab companies proved us right—there were no taxis available in the area. It would be better, said Farad, to walk to the main road and hail a cab from there. Reluctant to end the evening at the elevator, I locked my door and joined my friends on the walk out to Mipur Road, which even at midnight stirred with the occasional activity of tradesmen and drivers. After a few attempts, Farad flagged down a cab, negotiated a fare and recorded the driver's number. It was part of the safety training Mia and I had imbibed as foreigners over the years. Other examples included "Never buy spices from the sacks at the market" and "Never wear gold necklaces while riding rickshaws." "I should catch my bus," Farad announced after Mia's departure. "But you've left your books in my house," I replied. "I thought you were coming back to get them." Farad was incredibly sexy with his brooding face and shaggy black beard and I had hoped more time would reveal reciprocal interest. From one writer to another it was not a suggestive line, but I was too shy to be more explicit with my male friends in Bangladesh, who treated me as one of the boys and silenced me sometimes with their unexpectedly conservative views of women. Farad considered my comment. "I'll collect them later, or we can meet at the university in a few days. Do you need to catch a rickshaw to your door?" "I don't have any taka on me," I said, "and it's not far." I was, after all, in my own street, not being chauffeured home by a bleary-eyed driver. "Thanks for coming! Abar dekha hobe (see you again)." "Goodnight," Farad replied and as he turned to leave I saw him grin into his beard, amused by my tipsy pronunciation. Fatigue dropped heavily on my shoulders as I strolled back down the road. My flat, with its small clean bed and softly purring ceiling fans, seemed far away at the end of the alley. It was very quiet, as quiet as home when I used to walk through the city to the train station after late night shifts on the suicide hotline. The dim light in the street exposed its emptiness. The stalls along the road had shut hours earlier and the only movement came from a middle-aged man taking his exercise, swinging his arms widely from side to side as he strode home. As I turned the first corner of the alley, another man approached me from behind. I glanced at him, probably because he had glanced at me. "Are you OK?" he asked. "Fine." "What is your country?" "Look," I said, unaccountably feeling my heart rate increase, "I'm sorry, but I don't want to talk now." "No problem, no problem," he assured me, spreading his hands and smiling, displaying two charming rows of teeth. "Relax. You're very nice." My instinct was to smile back. We walked past the waste piles that had been emptied from the bins, ready for sorting. The woman I exchanged greetings with worked here on most days and instructed me on how to wear my orna (scarf) when it wasn't placed correctly over my chest. I wondered now where she slept at night. Calculating the closeness of my friend seemed less like idle speculation when the man who was walking beside me stepped directly into my path. He was tall and lean and wore a dark blue shirt. His face gleamed, as if he had been sweating during the day and had not washed off the residue. It occurred to me to twist past him and walk faster, maybe even run. I considered how fast and how far I could go in my thongs and wondered if I should kick them off, and then start to run. "No problem," the man repeated, holding out his hands again, placing them tightly behind my neck. He pulled me towards the wall as he forced me back by moving closer. Instant wetness struck me as I felt the concrete—my pelvic floor had made the first start of surprise. The strong hands moved quickly from my neck to my breasts. "I just want to…" said the man, squeezing both breasts like he was selecting fruit. He added, "You're very nice." I was wearing the only remotely attractive bra I owned, purchased from the supermarket on Dhanmondi 27. The cups, moulded from black synthetic lace, made my chest stick out in jaunty cones like a 1950s sex-bomb and the underwire dug into my chest. Clothes can be armour, yet in this case had depleted my self-preservation. I stood quite still, thinking only of what might happen next. I was against a wall in an alleyway at midnight, with no-one around except the man who was groping me. Finally I reacted, though it was not the reaction I would have guessed at my most objective self. Cowgirls get the blues, rough beasts slouch to be born and six foot one kick-boxing world travelling feminists scream like frightened cats with the shock of even minor violation. And certain men, I learned on my night out, chuckle at the distress they cause and then run away. After A Night Out The personal and public impacts of A Night Out proved to be cumulative over time and throughout retellings. When I read the piece at the Dhaka conference I was set to unleash the "transformative and efficacious potential" that autoethnography legendarily contains (Spry 712), though if my revelation achieved anything close to such a transformation, it was unclear. A female academic who had been chatting with me before my presentation, left the room directly after it. The students, mainly female undergraduates, had no questions to ask about any aspect of my paper. Whatever reactions my audience felt, if any, were not discussed. After my presentation, the male convenor privately expressed his regret over my experience and related more horrific examples. Sexual harassment of women is prevalent in Bangladesh yet so too is the culture of blaming the victim and denying the crime (cf. Lodhi; Mudditt; Nadiya), an attitude reflected through the use of the term "Eve Teasing," which assigns the provocative role to the woman and normalises the aggressive or sexual actions of the perpetrator (Kabeer 149). The response of this liberal and thoughtful man to my revelation was the only one that was articulated. By this measurement, A Night Out had failed to make the desired impact. One of the greatest reasons for this was the tension between the personal motivation behind my revelation and the public impact I had optimistically expected. A Night Out omits the reactions of my community immediately after my assault, when I was chastised for walking alone at such at late hour and for failing to defend myself, particularly given my size. In my street, gossip spread that I had not been groped but mugged, a less lecherous so perhaps more acceptable offense. I read A Night Out partly to gain some retrospective acknowledgement of my experience and in my determination I defied the complexities of a conservative country…[in which] women do not live alone, do not have male friends, do not travel by themselves or smoke cigarettes publicly and most definitely [...] do not talk or write about sexual topics. In Dhaka these things matter and 'decent women' are supposed to play by the rules. (Deen 35) Although I observed this conservatism to varying degrees in Bangladesh, I know that when women play outside the rules, negotiating cultural norms becomes a process of "alliance and conflict" that requires sensitivity to practise (Akhter 22)—a sensitivity that is difficult to grasp. The career of Bangladeshi writer Taslima Nasrin illustrates this: credited with opening doors of feminist discussion "that had been shuttered by genteel conservatism, by niceness, by ignorance and denial" (Nadiya), Nasrin diminished this effect and alienated her audience through subsequent "shock tactics and sensationalism" (Deen 56). Although my revelation had also alienated my audience, it was not the impact I had hoped for. While Linda Park-Fuller celebrates autoethnographic performance as a "transgressive act—a revealing of what has been kept hidden, a speaking of what has been silenced" (26), the conference experience made me realise the significance of cultural context to the impact of revelation. I considered recasting A Night Out in a setting that was more intimate than academic, to an audience prepared for the content and united by achieving a specific outcome, where responses could be given privately if desired. I would also have to shift my role from defiant storyteller to one who welcomed all types of feedback. By posting A Night Out online as a Facebook note, I not only fulfilled the requirements above but made the story accessible to a large audience of men and women of diverse cultural backgrounds, including Bangladeshi. The written replies I received were easier to decipher than the faces after the conference presentation. Among the responses, some from people I did not know at all, many conveyed their appreciation for the description of Bangladesh. Others commented on the risk I took in walking down the road at night and suggested ways I could defend myself in future. I was told I was tough to write the account and was invited to share more of my experiences. One friend in Bangladesh shared my note with others and wrote to describe the reaction of a female friend of his who was "terribly shocked" by what I had written about my breasts, more than my attraction to Farad or the sexual assault itself. This anonymous respondent's "pure cultural shock", which my conference audience may also have felt, was better communicated through the Facebook retelling of A Night Out, although I am unable to interpret the silence of the other Bangladeshi women I sent the note to. While the responses I received indicated my revelation had made some impact in its online context, I could not help being especially touched when a male friend wrote, "And as a Bangladeshi I feel sorry for [your trouble]." It is one matter to write up a personal experience and another to have it make a public impact. As my first reading of A Night Out shows, autoethnographic revelation contains the potential to alienate as well as to create sympathy with an audience. Combined with the second, more private and accessible, distribution of A Night Out, this "Before" and "After" analysis shows the evolution of the revelation's impact on my audience as well as myself, over time and within different cultural contexts, in the academic, social and online arenas. Although my experience confirms the impact autoethnography can make as a form of cultural research, it can only be strengthened by continued attempts to seek a balance between the projections and inflections of culture, self and audience. It is not only in the telling but in the re-telling that personal revelations will gather and continue to give impact, which is why I now present A Night Out to a new audience in a new context and await your new responses. References Akhter, Farida. Seeds of Movements: On Women's Issues In Bangladesh. Dhaka: Narigrantha Prabartana, 2007. Deen, Hanifa. Broken Bangles. New Delhi: Penguin, 1998. Ellis, Carolyn. The Ethnographic I: A Methodological Novel about Autoethnography. Walnut Creek: AltaMira P, 2004. Four Arrows. The Authentic Dissertation: Alternate Ways of Knowing, Research, and Representation. London: Routledge, 2008. Gandhi, Leela. Postcolonial Theory: A Critical Introduction. St Leonards: Allen and Unwin, 1998. Kabeer, Naila. Reversed Realities: Gender Hierarchies in Development Thought. London: Verso, 1994. Lodhi, Muhamad. "Reply." Unheard Voice: All Things Bangladesh. 25 Jun. 2011. 5 Oct. 2011 ‹http://unheardvoice.net/blog/2011/06/24/silence/#comments›. Mudditt, Jessica. "Mugged, Dragged and Scarred: Harrowing Tales from Foreigners In Dhaka." The Independent Digital 23 Aug. 2011: 1-2. Nadiya, Shabnam. "Woman Alone." The Daily Star—Features. 29 Sep. 2008. 5 Oct. 2011 ‹http://www.thedailystar.net/suppliments/2008/eid_special/woman.htm›. Park-Fuller, Linda. "Performing Absence: The Staged Personal Narrative as Testimony." Text and Performance Quarterly 20 (2000): 20–42. Richardson, Laurel. "Narrative Sociology." Representation in Ethnography. Ed. John Van Maanen, Thousand Oaks: Sage, 1995. 198–221. Sparkes, Andrew C. "Autoethnography: Self-Indulgence or Something More?" Ethnographically Speaking: Autoethnography, Literature and Aesthetics. Eds. Arthur Bochner and Carolyn Ellis. Walnut Creek: AltaMira, 2002. 209–32. Spry, Tami. "Performing Autoethnography: An Embodied Methodological Praxis." Qualitative Inquiry 7.6 (2001): 706–32. Ware, Vron. Beyond the Pale: White Women, Racism and History. London: Verso, 1992.

This study analyzes current trends in metrology in the field of portable coordinate measuring machines and describes current methods for measurement system and process evaluation. Obtained knowledge is applied, in order to evaluate the capability of measurement system, which consists of articulated measurement arm and measurement standard.

Reverse engineering is the technique of gathering scientific knowledge about a part by physically examining it. In the computer aided manufacturing world this is referred to as Part to CAD conversion, where the geometry of physical objects are being captured as Digital 3-D CAD Data. This is vital not only to produce drawing of parts for which no CAD data exists, but also is frequently being used to produce better designs. The industry professionals to achieve this are frequently using Coordinate Measuring Machine [CMM] among other tools. The purpose of this thesis is to demonstrate the versatility of portable CMM as a Reverse Engineering Tool through application experiments aimed at industrial and non-industrial solutions. The thesis also researches in to the feasibility of customization options through experimentations focused on reverse engineering. Focusing further on Reverse Engineering applications, some of the interesting digitizing and CAD techniques are demonstrated and compared.
M.S.
Department of Industrial Engineering and Management Systems
Engineering and Computer Science
Industrial Engineering and Management Systems

This study takes advantage of digital surveying to investigate in reverse the complexity and creativity of architectural composition in religious Baroque buildings while studying a so-called minor architecture, the church of Santa Maria dell'Odigitria in Acireale (CT), whose interior is modeled with geometric rigor, through a design process that is based on the use of simple geometric figures but articulated differently, such as to structure a complex structural and proportional order. The three-dimensional space of a computer instead becomes the core of the unveiling process, the place where the scholar has the opportunity to interact and communicate with millions of points gained, to reason on the geometric and spatial qualities of the object; where the geometric intuition about the genesis of the shape can be verified in real time through a simple query / overlap, in which one can move from measurement to representation, from the spatiality of the real to its discretization and viceversa.

Solving issues in testing articulated arm coordinate measuring machines by bringing homogeneity to the process was the intention of the standard but it also had the consequence of being difficult to comply with in 100% totality. Accessibility to appropriate testing standards, whether financially or in their inherent stability can prove very difficult for a commercial calibration laboratory. Through hours of design & build and with deep testing resources, Trescal has created a platform from which AACMM with effective diameters up to 10.5 ft can be tested for touch measurement, and ISO17025 accredited, with full compliance to the B89 standard.

Abstract Prelude Floating Liquefied Natural Gas (FLNG) facility reached a significant milestone in June 2018 when gas was introduced onboard for the first time as part of the facility startup process, loaded from an LNG carrier moored in side-by-side (SBS) configuration. This first offshore LNG SBS operation allowed Prelude’s utilities to switch from running on diesel to running on gas. SBS mooring is the base case configuration for of floading both LNG and Liquefied Petroleum Gas (LPG) into product carriers using Marine Loading Arms (MLA) once the Prelude FLNG facility is fully operational. These complex and weather sensitive operations are expected to take place on a weekly basis. This means critical decisions about weather-window and timing should be supported as much as possible by predictive analysis and modelling of environment forecasts to reduce the risks. Prelude Floating Liquefied Natural Gas (FLNG) is designed to offload Liquefied Natural Gas (LNG) and Liquefied Petroleum Gas (LPG) to carrier vessels moored in a side-by-side (SBS) configuration, using Marine Loading Arms (MLA) technology. For onshore terminals or small/medium FLNG, the traditional design of MLA (Double Counterweight Marine Arm – DCMA), featuring a vertical riser, can be used. However due to the exceptional freeboard of Prelude a new type of MLA was designed, namely the Offshore Loading Arm Footless (OLAF), without vertical riser in order to reach the LNG or LPG manifolds located as far as about 16 meters below the MLA base. Thanks to the OLAF design, the length and weight of the articulated MLA sections is reduced in comparison with conventional DCMA, and so are the dynamic loads applied by the MLA on the vessel manifold, which was mandatory to remain below the acceptable stress limit of standard LNG/LPG carrier manifolds. OLAF employs the field proven targeting system (TS) allowing the connection and disconnection of the MLA to the vessel manifold in dynamic conditions. This paper describes the assumptions and process to design and validate this new system — in terms of overall geometry and structural design, while verifying project feasibility, aiming at a reliable design of all components and minimizing the risks during operations. The key challenges and lessons learnt are also discussed. This innovative type of MLA had to be thoroughly designed and tested before being manufactured and assembled on the FLNG. The innovation management was also coupled with the additional challenge imposed by the expected highly dynamic conditions of relative motion between vessels that were never encountered for such systems in the past. MLA were designed with the objective to cover the operable envelope induced by berthing, mooring and relative motion criteria, so that it should not become an additional criterion in general. Since such an envelope is larger for this offshore application compared to sheltered terminals, this objective was particularly challenging but could be met thanks to the OLAF design. The SBS hydrodynamic numerical model is based on potential theory and includes multi-body coupling, non-linear mooring characteristics and coupling with sloshing. This model was calibrated using wave basin tests with a good agreement, and was used to determine the maximum operable environments and associated MLA envelope, using a 39-year hindcast for various LNG carriers and considering a scenario with different criteria and loading conditions. More than 100,000 time-domain simulations were required to evaluate non-linear quantities on a reduced set of environment ‘bins’. The new OLAF-type MLA was developed using these hydrodynamic simulations. Specific processes — based on spectral screening and selection using relevant criteria — were used to identify and select, in a systematic way, the designing load cases for connecting, connected, and emergency disconnection cases, while complying with the maximum allowable loads of conventional LNG and LPG carrier manifolds. An instrumented 1:4 OLAF scale model was built and tested with 6 degrees of freedom hexapods reproducing the motions on both sides of the OLAF which enabled us to confirm a 10% accuracy of the numerical studies results. The actual OLAF were dynamically tested with a full scale motion simulator before shipment to the yard for installation. The successful first operations were performed safely and confirmed the validity of the design. Measurements are now collected onboard Prelude to verify the design and when possible improve the accuracy of numerical modelling.