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Artykuły w czasopismach na temat "Payload transportation operations"
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Brown, Mark W. "Evaluation of the Impact of Timber Truck Configuration and Tare Weight on Payload Efficiency: An Australian Case Study". Forests 12, nr 7 (28.06.2021): 855. http://dx.doi.org/10.3390/f12070855.
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The forest industry tends to plan, and model transportation costs based on the potential payload benefits of increased legal gross vehicle weight (GVW) by deploying different configurations, while payload benefits of a configuration can be significantly influenced by the vehicle design tare weight. Through this research the relative benefit of increased legal GVW of different configurations is compared across Australia over a 13-year period from 2006 to 2019, by examining data collected post operation across multiple operations. This approach is intended to offer realistic insight to real operations not influenced by observation and thus reflect long-term operating behaviour. The inclusion of the three most common configuration classes in Australian forestry over a 13-year period has also allowed the exploration of load management between configurations and potential trends over time. When considering the legal GVW and the tare weight impacts across the fleets, the semi-trailer has an 8 t payload disadvantage compared to B-Doubles and 19.6 t disadvantage compared to road trains.
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Salmin, V. V., A. A. Kvetkin i A. S. Russkikh. "Choice of mission trajectory plans and conceptual design of electrical propulsion module for launching payloads into circumterrestrial orbits". VESTNIK of Samara University. Aerospace and Mechanical Engineering 19, nr 4 (31.12.2020): 58–69. http://dx.doi.org/10.18287/2541-7533-2020-19-4-58-69.
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The problem of increasing the efficiency of transport operations in space is currently coming to the fore. In the context of this problem, we investigated the possibility of developing a space transportation system including a chemical upper stage and an electric propulsion transport module capable of performing a specified range of space maneuvers. Electric propulsion module design was carried out for a given range of target orbits and payload mass with the provision of restrictions on the flight time. Calculation of the ballistic characteristics of the flight is performed and an optimal program of placing a low-thrust vehicle into orbit is defined. A procedure for defining the design parameters of a space transportation system and its conceptual design is proposed. The conceptual design of the space transportation system and the electric propulsion module were formed in the PTC Creo Parametric environment. On the basis of the results of the work, it can be concluded that it is possible to create a space transportation system with given parameters.
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Thamm, F. P., N. Brieger, K. P. Neitzke, M. Meyer, R. Jansen i M. Mönninghof. "SONGBIRD – AN INNOVATIVE UAS COMBINING THE ADVANTAGES OF FIXED WING AND MULTI ROTOR UAS". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-1/W4 (27.08.2015): 345–49. http://dx.doi.org/10.5194/isprsarchives-xl-1-w4-345-2015.
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This paper describes a family of innovative fixed wing UAS with can vertical take off and land – the SONGBIRD family. With nominal payloads starting from 0.5 kg they can take off and land safely like a multi-rotor UAV, removing the need for an airstrip for the critical phases of operation. A specially designed flight controller allows stable flight at every point of the transition phase between VTOL and fixed wing mode. Because of this smooth process with a all time stable flight, very expensive payload like hyperspectral sensors or advanced optical cameras can be used. Due to their design all airplanes of the SONGBIRD family have excellent horizontal flight properties, a maximum speed of over 110 km/h, good gliding properties and long flight times of up to 1 h. Missions were flown in wind speeds up to 18 m/s. At every time of the flight it is possible to interrupt the mission and hover over a point of interest for detail investigations. The complete flight, including take-off and landing can be performed by autopilot. Designed for daily use in professional environments, SONGBIRDs are built out of glass-fibre and carbon composites for a long service life. For safe operations comprehensive security features are implemented, for example redundant flight controllers and sensors, advanced power management system and mature fail safe procedures. The aircraft can be dismantled into small parts for transportation. SONGBIRDS are available for different pay loads, from 500 g to 2 kg. The SONGBIRD family are interesting tools combining the advantages of multi-copter and fixed wing UAS.
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Mathanlal, Thasshwin, Anshuman Bhardwaj, Abhilash Vakkada Ramachandran, María-Paz Zorzano, Javier Martín-Torres, Charles S. Cockell, Sean Paling i Tom Edwards. "Subsurface robotic exploration for geomorphology, astrobiology and mining during MINAR6 campaign, Boulby Mine, UK: part I (Rover development)". International Journal of Astrobiology 19, nr 2 (3.10.2019): 110–25. http://dx.doi.org/10.1017/s147355041900020x.
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AbstractAutonomous exploration requires the use of movable platforms that carry a payload of instruments with a certain level of autonomy and communication with the operators. This is particularly challenging in subsurface environments, which may be more dangerous for human access and where communication with the surface is limited. Subsurface robotic exploration, which has been to date very limited, is interesting not only for science but also for cost-effective industrial exploitation of resources and safety assessments in mines. Furthermore, it has a direct application to exploration of extra-terrestrial subsurface environments of astrobiological and geological significance such as caves, lava tubes, impact or volcanic craters and subglacial conduits, for deriving in-situ mineralogical resources and establishing preliminary settlements. However, the technological solutions are generally tailor-made and are therefore considered as costly, fragile and environment-specific, further hindering their extensive and effective applications. To demonstrate the advantages of rover exploration for a broad-community, we have developed KORE (KOmpact Rover for Exploration); a low-cost, re-usable, rover multi-purpose platform. The rover platform has been developed as a technological demonstration for extra-terrestrial subsurface exploration and terrestrial mining operations pertaining to geomorphological mapping, environmental monitoring, gas leak detections and search and rescue operations in case of an accident. The present paper, the first part of a series of two, focuses on describing the development of a robust rover platform to perform dedicated geomorphological, astrobiological and mining tasks. KORE was further tested in the Mine Analogue Research 6 (MINAR6) campaign during September 2018 in the Boulby mine (UK), the second deepest potash mine in Europe at a subsurface depth of 1.1 km, the results of which will be presented in the second paper of this series. KORE is a large, semi-autonomous rover weighing 160 kg with L × W × H dimensions 1.2 m × 0.8 m × 1 m and a payload carrying capacity of 100 kg using 800 W traction power that can power to a maximum speed of 8.4 km h−1. The rover can be easily dismantled in three parts facilitating its transportation to any chosen site of exploration. Presently, the main scientific payloads on KORE are: (1) a three-dimensional mapping camera, (2) a methane detection system, (3) an environmental station capable of monitoring temperature, relative humidity, pressure and gases such as NO2, SO2, H2S, formaldehyde, CO, CO2, O3, O2, volatile organic compounds and particulates and (4) a robotic arm. Moreover, the design of the rover allows for integration of more sensors as per the scientific requirements in future expeditions. At the MINAR6 campaign, the technical readiness of KORE was demonstrated during 6 days of scientific research in the mine, with a total of 22 h of operation.
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Demircali, Anil, i Huseyin Uvet. "A STUDY OF UNMANNED GLIDER DESIGN, SIMULATION, AND MANUFACTURING". CBU International Conference Proceedings 5 (24.09.2017): 1064–70. http://dx.doi.org/10.12955/cbup.v5.1072.
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This paper describes a mini unmanned glider's design, simulation, and manufacturing with a wing-folding mechanism. The mini-glider is designed for the CANSAT 2016 competition, which has the theme of a Mars glider concept with atmosphere data acquisition. The aim is to facilitate transportation and to land it to the destination point. Having a light and compact design is important since it is a glider without an engine and it uses power only for the transmission of sensory data. The glider is produced with a wingspan which is 440 mm, and its longitudinal distance is 304 mm. The wings can be packaged in a fixed size container whose dimensions are 125 mm in diameter and 310 mm in height. The glider's weight is only 144 gr, and it can increase up to 500 gr with maximum with payload. The mechanism, which includes springs and neodymium magnets for wing-folding, is capable of being ready in 98 ms for gliding after separation from its container. The mini-glider is capable of telemetry, communications, and other sensory operations autonomously during flight.
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Demircali, Ali, i Huseyin Uvet. "Mini Glider Design and Implementation with Wing-Folding Mechanism". Applied Sciences 8, nr 9 (3.09.2018): 1541. http://dx.doi.org/10.3390/app8091541.
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This paper describes a mini unmanned glider’s design, simulation, and manufacturing with a novel wing-folding mechanism. The mini-glider is designed for CanSat competition, which has a theme of a Mars glider concept with atmosphere data acquisition. The aim is to facilitate the transportation of the glider and to land it on the destination point by following strict rules. Having a light and compact design is important since it uses power for the transmission of sensory data only. Dimensions of the glider is produced with a wingspan that is 440 mm and a length of 304 mm. The wings can be stowed in a fixed size container that has a diameter of 125 mm and a height of 310 mm. Its weight is only 144 g and it can increase up to 500 g maximum with a payload. The mechanism, which includes springs and neodymium N48 grade magnets for a wing-folding system, is capable of being ready in 98 ms for gliding after separating from its container. The mini-glider is capable of telemetering, communicating, and conducting other sensory operations autonomously during the flight.
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Borz, Stelian Alexandru, Marina Viorela Marcu i Maria Francesca Cataldo. "Evaluation of an HSM 208F 14tone HVT-R2 Forwarder Prototype under Conditions of Steep-Terrain Low-Access Forests". Croatian journal of forest engineering 42, nr 2 (14.01.2021): 185–200. http://dx.doi.org/10.5552/crojfe.2021.775.
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Forwarding technology is well established in use around the world but, at the same time, forwarders are expensive machines that require a good planning to ensure the sustainability of operations. In addition, forwarder market is characterized by a limited pool of customers, therefore innovation attempts may be limited compared to other product development industries. Since the steps towards a full automation of operations are still at their beginning, improvements of forwarder machines may rest in developing and integrating components that could contribute to an increased effectiveness. To respond to such challenges, the Forwarder2020 project developed innovative components that were integrated in a number of forwarder prototypes based on a market pull approach that resulted in a flexible adaptation to customer requirements and work environments. Since one of the typical work environments was that of low access forests, some components (i.e. suspended cabin and transmission system) were engineered to enable faster and safer operations and to economize fuel. As a common validation step is that of bringing field evidence on the performance improvement, this study evaluated the operational speed, productivity and fuel consumption of a forwarder prototype in conditions of a steep-terrain low-access forest. The main findings were very promising as the prototype was able to operate at significantly increased speeds and the fuel savings were evident. For an average forwarding distance of about 1.5 km, net productivity and efficiency rates were estimated at 14.4 m3/h and 0.07 h/m3, respectively. They were related to the availability of wood, and further improvement of such figures is possible by a better organization of tree felling and processing. Operational speed was affected by the condition of skid roads used for forwarding, which were harsh. During the transportation tasks developed on roads typical for forwarding, the machine was able to sustain average speeds estimated at 8 km/h. As a matter of fact, in such tasks, the dominant operational speed (almost in 100% of the cases) was higher than 5 km/h irrespective of the road condition. Hourly fuel consumption was estimated based on the time in which the engine was working and it amounted to 17.1 l/h. More importantly, by considering the forwarded payload in terms of volume and mass, the unit fuel consumption was estimated to be 1.25 l/m3 and 1.47 l/t, respectively. These results bring evidence on the performance improvement by modular innovation. In fact, such solutions could answer the challenges related to the sustainability of forest operations in low access forests.
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Garren, Austin M., M. Chad Bolding, W. Michael Aust, Angelo C. Moura i Scott M. Barrett. "Soil Disturbance Effects from Tethered Forwarding on Steep Slopes in Brazilian Eucalyptus Plantations". Forests 10, nr 9 (22.08.2019): 721. http://dx.doi.org/10.3390/f10090721.
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Traditional timber harvests on steep slopes have been conducted through labor-intensive and sometimes environmentally impactful methods, such as manual felling with chainsaws and extraction using bladed skid trails, winching, or cable yarding. Ground-based mechanized harvesting and primary transportation methods such as cut-to-length harvesters and forwarders have emerged in some parts of the world as low-impact, safe, and efficient alternatives to the aforementioned systems. However, when mechanized operations are used on steep terrain, problems such as poor stability, loss of traction, and increased soil disturbance can occur. Tethered or winch-assisted logging practices are being tested and applied in several countries to adapt to challenges associated with operating equipment on steep slopes while minimizing environmental impact. To better understand the feasibility of these systems, we conducted a designed experiment to quantify changes in soil properties and predicted erosion resulting from varying numbers of passes and payload levels by a forwarder operating on slopes ranging from 27 to 38 degrees. The machine was equipped with two different track configurations, tethered by either a machine-mounted or self-contained winch, in eucalyptus plantations in Brazil. On low slopes, bulk density significantly increased, but it did not increase on steeper slopes; this demonstrates traction winches’ effectiveness at reducing concentrated ground pressures. Rut depths were minimal and decreased with increasing slope classes due to reduced track slippage. Predicted erosion rates were high, primarily due to the extremely steep, long slopes and lack of adequate cover in some portions of the trail, illustrating the importance of proper erosion management practices on steep slopes.
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Franko, Josef, Shengzhi Du, Stephan Kallweit, Enno Duelberg i Heiko Engemann. "Design of a Multi-Robot System for Wind Turbine Maintenance". Energies 13, nr 10 (18.05.2020): 2552. http://dx.doi.org/10.3390/en13102552.
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The maintenance of wind turbines is of growing importance considering the transition to renewable energy. This paper presents a multi-robot-approach for automated wind turbine maintenance including a novel climbing robot. Currently, wind turbine maintenance remains a manual task, which is monotonous, dangerous, and also physically demanding due to the large scale of wind turbines. Technical climbers are required to work at significant heights, even in bad weather conditions. Furthermore, a skilled labor force with sufficient knowledge in repairing fiber composite material is rare. Autonomous mobile systems enable the digitization of the maintenance process. They can be designed for weather-independent operations. This work contributes to the development and experimental validation of a maintenance system consisting of multiple robotic platforms for a variety of tasks, such as wind turbine tower and rotor blade service. In this work, multicopters with vision and LiDAR sensors for global inspection are used to guide slower climbing robots. Light-weight magnetic climbers with surface contact were used to analyze structure parts with non-destructive inspection methods and to locally repair smaller defects. Localization was enabled by adapting odometry for conical-shaped surfaces considering additional navigation sensors. Magnets were suitable for steel towers to clamp onto the surface. A friction-based climbing ring robot (SMART— Scanning, Monitoring, Analyzing, Repair and Transportation) completed the set-up for higher payload. The maintenance period could be extended by using weather-proofed maintenance robots. The multi-robot-system was running the Robot Operating System (ROS). Additionally, first steps towards machine learning would enable maintenance staff to use pattern classification for fault diagnosis in order to operate safely from the ground in the future.
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Hyla, Paweł, Agnieszka Kosoń-Schab, Janusz Szpytko i Jarosław Smoczek. "Integrated Supervision for Supporting Control and Proactive Maintenance of Material Handling System". Journal of KONES 26, nr 1 (1.03.2019): 65–72. http://dx.doi.org/10.2478/kones-2019-0008.
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Abstract Material handling systems, as an important part of different type of manufacturing processes, face the same challenges as manufacturing industries pushed nowadays forward by innovative ideas and technologies to the next level loudly announced as industry 4.0. Development of the next generation of automated manufacturing systems involves advanced approaches to material handling systems design and their close integration with the higher levels of manufacturing and production control and management, e.g. manufacturing execution systems (MES), enterprise resource planning (ERP). In the presence of increasing demands for manufacturing process optimization, the role of supervisory level of material handling systems is much more advanced today, ensuring not only data acquisition, visualization, monitoring, supervisory control, as well as synchronization with the higher control levels (FEM, ERP), but also providing functionality for supporting maintenance and decision-making processes to reduce downtimes, operations and maintenance costs. The article deals with the integration of control and maintenance functions in the hierarchical control system of a crane. The supervisory system for supporting control and proactive maintenance is prototyped at the laboratory overhead travelling crane. The article presents the control-measurement equipment and intelligent software tools implemented in the supervisory control and data acquisition (SCADA) system to aid decision-making process in proactive maintenance. The overview of the main components of the supervisory control and proactive maintenance subsystems is provided, and their respective role in control, supervision, and proactive maintenance is explained. The crane’s supervisory control includes the stereovision-based subsystem applied to identify the crane’s transportation workspace, determine the safety and time-optimal point-to-point trajectory of a payload. The proactive maintenance module consists of the human machine interface (HMI) supporting decision-making process, intelligent tools for upcoming downtime/failure prediction, and the crane's girder inspection using the metal magnetic memory technique.
Rozprawy doktorskie na temat "Payload transportation operations"
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Sgarioto, Daniel Emmanuel, i s9908712@student rmit edu au. "Non-linear Dynamic Modelling and Optimal Control of Aerial Tethers for Remote Delivery and Capture of Payloads". RMIT University. Aerospace, Mechanical and Manufacturing Engineering, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20070209.144754.
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Many potentially useful applications that broadly fall under the umbrella of payload transportation operations have been proposed for aerial towed-cable (ATC) systems, namely the precise capture and delivery of payloads. There remain outstanding issues concerning the dynamics and control of ATC systems that are inhibiting the near-term demonstration of these applications. The development of simplified representations of ATC systems that retain the important dynamics, yet are simple enough for use in control system development is limited. Likewise, little research exists into the development of controllers for ATC systems, especially the development of towing strategies and cable-based control techniques for rendezvous and payload transportation. Thus, this thesis presents novel research into the development of control strategies and simulation facilities that redress these two major anomalies, thereby overcoming a number of hitherto unresolved issues. The primary objective of this thesis is to develop innovative non-linear optimal control systems to manoeuvre a cable towed beneath an aircraft to transport payloads both to and from surface locations. To appropriately satisfy this objective, accurate and efficient modelling capabilities are proposed, yielding the equations of motion for numerous models of the ATC system. A series of techniques for improving the representativeness of simple dynamical models were developed. The benefits of using these procedures were shown to be significant and possible without undue complexity or computational expense. Use of such techniques result in accurate simulations and allow representative control systems to be designed. A series of single and multi-phase non-linear optimal control problems for ATC systems are then formally proposed, which were converted into non-linear programming problems using direct transcription for expedient solution. The possibility of achieving accurate, numerous instantaneous rendezvous of the cable tip with desired surface locations on the ground, in two and three-dimensions, is successfully demonstrated. This was achieved through the use of deployment and retrieval control of the cable and/or aircraft manoeuvring. The capability of the system to safely and accurately transport payloads to and from the surface via control of the cable and/or aircraft manoeuvring is also established. A series of parametric studies were conducted to establish the impact that various parameters have on the ability of the system to perform various rendezvous and payload transportation operations. This allowed important insights into to the nature of the system to be examined. In order for the system to perform rendezvous and payload transportation operations in the presence of wind gusts, a number of simple closed loop optimal feedback controllers were developed. These feedback controllers are based on the linear quadratic regulator control methodology. A preliminary indication of the robustness of ATC systems to wind gusts is provided for through a succession of parametric investigations. The performance of the closed-loop system demonstrates that precise and robust control of the ATC system can be achieved for a wide variety of operating conditions. The research presented in this thesis will provide a solid foundation for further advancing the development of aerial tether payload transportation technology.
Części książek na temat "Payload transportation operations"
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Palaszewski, Bryan. "Martian Moons and Space Transportation Using Chemical and Electric Propulsion Options". W Solar Planets and Exoplanets [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.96717.
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Using chemical and nuclear electric propulsion for the exploration of the Martian moons will be investigated. Both oxygen/hydrogen chemical propulsion and nuclear electric propulsion with 500 kilowatt electric (kWe) to 10 megawatt electric (MWe) reactors will be assessed. The initial masses, propellant masses, and trip times for a variety of space vehicle payload masses will be compared. For high energy orbital transfer, the nuclear electric propulsion vehicles required a small fraction of the propellant mass over oxygen/hydrogen orbital transfer vehicles (OTVs). The moons, Phobos and Deimos, may hold resources for refueling future space vehicles. In-situ resource utilization (ISRU) can be a powerful method of reducing Earth dependence on space vehicle propellants, liquid water, and breathing gases. Historical studies have identified the potential of water in carbonaceous chondrites on the moons. The moon-derived propellants OTVs that move payloads between the moons and to other important operational Mars orbits. Also, the propellants have been suggested to support reusable Mars landers. To extract the water, the mined mass, its volume and the mining time were estimated. The water mass fraction may be as low as 2x10−4. Very large masses were needed to be extracted for up to 100 MT of water.
Streszczenia konferencji na temat "Payload transportation operations"
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Clauss, Gu¨nther F., Hans W. Gerber i Carsten Hippe. "ASTRA: An Automatic Spading Tool for the Remote Application at Abyssal Depths". W ASME 2003 22nd International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2003. http://dx.doi.org/10.1115/omae2003-37171.
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The future approach of the European marine research programme focuses on the establishment of multi-disciplinary networks including existing systems, and the development of new technologies for efficient installation and near real time communication. Within this framework the European Community funds the networks ORION (Ocean Research by Integrated Observation Networks - GEOSTAR 3) and ESONET 2 (European Seafloor Observatory NETwork) with several European partner institutions involved in marine research. Key technologies for deep-sea research have been developed in the frame of the GEOSTAR project (GEophysical and Oceanographic STation for Abyssal Research - Deep-Sea Mission). The concept comprises: • the deep-sea benthic observatory for geophysical and oceanographic purposes with its unique Data Acquisition and Control System (DACS), • the innovative underwater communication system as near real time interface, and • the deployment and recovery vehicle MODUS (MObile Docker for Underwater Sciences) for precise operations with heavy payloads. The know-how and existing equipment establishes a good basis for extensions and further developments to be used for network projects. ASTRA — an Automated Spading Tool for Remote Applications at abyssal depths — is one of these new concepts. This tool — integrated into the GEOSTAR-Bottom Station (BS) (also called node) and deployed by MODUS — will bury an Ocean Bottom Seismometer (OBS) into the sub-sea soil. The OBS will be laterally displaced to the node and connected by an umbilical. At the end of a long-term mission the node will be recovered by MODUS and the OBS is pulled out of the ground hanging underneath the node. Both components, node and OBS, will be recovered by the surface research vessel. Equipment and procedures developed within the GEOSTAR project have been focused on providing a long-term stationing on the ocean floor to perform scientific measurements. The ASTRA concept takes a next step and aims for the interaction with its environment. Based on the proven and reliable combination of the deep sea shuttle MODUS for heavy load transportation and the payload Bottom Station as the carrier of equipment the new module ASTRA will extend the spectrum of scientific operating possibilities in the deep sea adding engineering services. An iterative process with an integrated design application of a 3D-CAD-system, FEM structural analysis and Multibody Simulation (MBS) characterizes the development phase of ASTRA. Using virtual mock-up critical aspects of handling and operation can be identified, and in consequence more easily avoided. Simulation results are validated by experimental investigations. Operations with the ASTRA prototype and the complete network-system will be performed in the Tyrrhenian Sea in late summer 2003.
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Matveev, Konstantin I., i Zachary J. Malhiot. "Construction and Testing of Radio-Controlled Power Augmented Ram Model". W ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-41136.
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Heavy-payload Power Augmented Ram vehicles represent a new class of amphibious transportation means. In the static and low-speed operational regimes, these machines utilize a skirtless pressurized air cushion generated by front jet propulsors. In the high-speed motion, the aerodynamic lift augmented in ground effect becomes the dominant support. The construction of a small-scale radio-controlled Power Augmented Ram model is described. Results of initial static and self-propelled tests on solid surfaces are presented. Future research work and possible full-scale applications are discussed.
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James, Daniel, i Maurizio Collu. "Aerodynamically Alleviated Marine Vehicle (AAMV): Bridging the Maritime-to-Air Domain". W SNAME 13th International Conference on Fast Sea Transportation. SNAME, 2015. http://dx.doi.org/10.5957/fast-2015-019.
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As high performance marine vessels with improved performance characteristics are being requested by governments (DARPA 2015) and commercial operators, the Aerodynamically Alleviated Marine Vehicle (AAMV) provides a solution that combines speeds typical of rotary-wing and light fixed-wing aircraft with payload and loitering ability found in current high speed craft. The innovative AAMV hybrid aero-marine platform utilizes an alternative implementation of wing-in-ground effect (WIG), a proven technology with a fascinating history of high speed marine operation. This paper outlines some challenges and the work completed towards the development of a hybrid class of vessel that is able to bridge the maritime-to-air domain, comfortably operating in the water surface yet still delivering the speed of aircraft during an airborne cruise phase. An overview of current WIG design is briefly presented, leading to the conceptual approach for the AAMV. Development and assessment of the aerodynamic properties of the lifting surfaces are shown, with analysis of several wing profiles and their effect on the total lift force, drag force, and pitching moment that directly influence the stability characteristics of the vehicle. A methodology for sizing an appropriate platform is summarized, along with experimental results of a high speed hullform with characteristics suitable for this intended application. Finally, particulars of a potential AAMV are derived using an iterative numerical method and briefly compared to current craft. For close to a century, the influence of ground effect has promised economy for low-skimming flight over smooth water (Raymond 1921), a promise that has yet to reach its full potential.
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Shust, William, i Corey Pasta. "Numerical Simulation of Freight Railcar Dynamic Clearance Envelopes". W ASME 2008 Rail Transportation Division Fall Technical Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/rtdf2008-74025.
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The operating dynamic clearance envelope has historically been a sum of estimated dimensional tolerances, sometimes even called “black magic” [1]. These tolerances exist by design within the car and the track, as well as between the wheel flanges and the rail gage face. Field observations of operating clearance have augmented these estimates. Recently a review of such expectations was desired as related to wide and/or tall payloads, with particular respect to train speed and track roughness. This project reexamines the factors affecting car body envelopes, including track curvature and elevation, and car parameters such as length, center of gravity (CG), and side bearing type. A particular goal of this study was to gain a rough understanding of the behavior expected relative to wide loads in the speed range of 30–50 mph. Both static analyses and dynamic negotiation of typical revenue track have been predicted. The NUCARS® multibody simulation software has been used to examine the influence of operating speed and FRA track class on the dynamic envelope. A summary of results is presented along with a discussion of general guidelines and additional considerations.
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Glossiotis, G., i I. Antoniadis. "Maximally Robust Sway Free Point-to-Point Transportation of Boom Crane Loads by a FIR Filtering Approach of the Motion Commands". W ASME 2005 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/detc2005-84846.
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A new method for sway suppression of boom crane loads is implemented, which is based on the application of appropriate filters on the motion commands. A typical boom crane mechanism is considered, which accomplishes independently the luffing and hoisting motions, needed for load grabbing, transfer and final positioning. The resulting dynamic model of the crane mechanism leads to a strongly non-linear and time varying problem. Property designed Finite Impulse Response (FIR) filters are then applied to the typical motion commands of the system. The resulting filtered motion commands are shown to effectively suppress the payload sway during and after the motion of the mechanism, leading to a minimization of the operating cycle of the crane. Additionally, due to the smooth nature of the resulting motion, decreased stresses result on the crane structure and the motion components, and thus, the life cycle of the equipment can be extended.
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Hopkins, Brad M., i Saied Taheri. "A Dynamic Wheel/Rail Interaction Model Based on an Euler-Bernoulli Beam Rail Model". W ASME 2011 Rail Transportation Division Fall Technical Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/rtdf2011-67003.
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Early detection of rail defects is necessary for preventing derailments and costly damage to the train and railway infrastructure. A rail surface flaw can quickly go from a small fracture to a broken rail after only a few train cars have passed over it. Rail defect detection is typically performed by using an instrumented car or a separate railway monitoring vehicle. Such systems can either be costly or time consuming to implement. This paper presents a dynamic wheel/rail interaction model for generating training data for a defect detection algorithm. The defect detection algorithm works with an onboard data acquisition system and sensor set consisting of accelerometers mounted to the bogie side frame. Side frame vertical acceleration signatures are analyzed by the algorithm to detect defects ranging from small surface fractures to rail breaks with complete rail separation. Proper training of the defect detection algorithm requires a large data set. This data set should consist of a wide range of train operating conditions and defect characteristics. Operating conditions of interest include various forward speeds and payloads, and defect characteristics of interest include rail fracture and break geometric parameters. To generate this training data, a dynamic wheel/rail interaction model was developed that relates crack/break geometry to the side frame vertical acceleration signature. The model was generated by treating the rail as an Euler-Bernoulli beam with appropriate boundary conditions and the pad-tie-ballast systems as discrete, evenly spaced lumped parameter forcing inputs into the rail system. The pad and ballast were each separately modeled as a non-linear spring and damper in parallel, and the sleeper was treated as a mass fixed between the spring and damper of the pad and ballast. The model was validated by comparing the simulated vertical acceleration response to actual bogie side frame vertical acceleration data.
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Liu, Tuanjie, Xiaohong Chen i Wei Ye. "Concept Selection Philosophy for Floating Control Facilities". W ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/omae2010-20805.
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Floating control facilities (FCFs) are designed to support fields using only subsea production system. Potential concepts, including Tension Leg Platform (TLP), Spar and semi-submersible can be selected as the FCFs. This paper discusses the philosophy of concept selection for FCFs. Two basic considerations for concept selection for FCFs are functional requirements and costs. Different structure types are first to be sized to meet the functional requirements for given water depths, environmental conditions and soil conditions. Then the costs for the procurement, construction, installation, hook up and commissioning for different concepts are estimated based on the sizes. Finally, the most cost-effective concept is chosen for further study to confirm the feasibilities of the concept by detailed analyses. Global sizing tools assisting concept selection have been developed by Ocean Dynamics LLC (Limited Liability Company) (ODL) over the past years. For a given concept, these sizing tools can find the optimized size based on costs to meet the functional requirements. Capabilities of the sizing tools cover the general layout, weight estimate (hull and deck), riser weight and stiffness estimate, loading conditions (transportation, normal operating, extreme, survival), hydrostatics and stability, natural periods, motions, air gap, environmental loads (wind, current, and mean wave forces), mooring sizing, cost estimate, and optimization based on the total costs. Two case studies in two different water depths, 140m and 1200m, are presented to illustrate the procedures and considerations in concept selection for floating control facilities. The FCFs used in the case studies are to support a Super Puma helideck, satellite communication equipment, an umbilical riser and option for a 3.5″ pipeline riser, with a total estimated topside payload as 400 Metric Ton (MT).
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Dumas, Antonio, Michele Trancossi i Stefano Anzillotti. "An Airship Design Methodology Based on Available Solar Energy in Low Stratosphere". W ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-38931.
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The actual applicative research concerning airships and their use as HAP (High Altitude Platforms for telecommunications and military use) presents new applicative hypothesis of these systems, also concerning energetic high quote production. Authors present the energetic balance of a high quote photovoltaic platform with capability of static hovering realized by electric powered propellers. This is the first step trough the design of the P. S. I. C. H. E. (Photovoltaic Space Island for Conversion of Hydrogen as Energy vector) airship concept: a stratospheric airship which could be considered a platform for hydrogen and oxygen production by photovoltaic. It investigates the behaviour of a similar platform operating at altitudes between 10 and 20 km, positioned at 45° latitude north [1, 2]. This paper analyses the design process for a High Altitude Platform based on photovoltaic energy caption, but the process could be generalized in order to be applied to any airship project. It is considers airship shapes equipped with large PV array that covers energy request during the day. Surplus in power supplies electrolyser equipments for hydrogen and oxygen production from water, which could be captured by atmospheric humidity or brought by an auxiliary airship. Hydrogen and Oxygen are compressed and stored in gas cylinders. With insufficient solar irradiance, with severe wind conditions and during the night, a fuel cell system fed by hydrogen and oxygen tanks supplies power requirements. The Standard Atmosphere Model is used to evaluate PV performance at various operative altitudes. A propulsion system with electric motors grants airship manoeuvrability and hovering. Energy balance of PV-hydrogen energy supply system has been analyzed for three airship shapes with equal volume with concern of overabundant hydrogen and oxygen production. Total weight and payload are calculated in relation to altitude. Storage tanks dimensions and products ground transportation frequency has been estimated. Hydrogen annual production for PV square meter has been evaluated in relation to ground production at the same latitude.