2,801 research outputs found
Integration of UAS in Air Traffic and Commercial Space Management
Unmanned Aircraft Systems (UAS) are going to be integrated into the National Airspace (NAS) as well as into the Single European Sky (SESAR). I. e. the European Roadmap describes a step by step approach with a full integration by 2028. Currently space vehicles are also developed to fly remotely piloted in space as well in near orbits or during reentry. Although they will fly without pilot operations on board, they may carry passengers or astronauts, respectively, or they will operate as a fully unmanned freighter to transport supply to the ISS or other space based stations. Currently these flights are operated in segregated airspace during launch and landing. When the number of flights will increase due to the commercialization of space transport, the use of restricted airspace will be no more feasible. To manage segregated airspace is costly and it is affecting the capacity of the air transport system. As the concepts and technology for air traffic insertion of UAS currently exist to a quite matured level, they should be also applied to space vehicles. A concept will be proposed which considers not to fully apply all rules for manned aircraft but to create a system for integration according to achieve an equivalent level of safety for unmanned aircraft and spacecraft
Commercial Space Transportation and Air Traffic Insertion - SESAR Requirements and the European Perspective
Commercial Space Transportation becomes an international business and requires landing
opportunities all over the world. Hence the integration of space vehicles in other airspace
than the US NAS is an important topic to be considered. The Single European Sky ATM
Research Programme (SESAR) is preparing the implementation of a new ATM system in
Europe. The requirements are defined by the concept of the shared Business Trajectory and
System Wide Information Management (SWIM).
Space vehicle operations are associated with the requested need for submitting an Mishap
Investigation Plan (MIP), containing responding and reporting procedures referring to
possible reentry or launch incidents or accidents. This leads to the submission of an
Emergency Response Plan (ERP), addressing information procedures about a planned
Reusable Launch Vehicle (RLV) mission of the airspace alerting and emergency services in
the areas of:
Emergency Detection
o Information relay between the Commercial Space Transportation (CST )
vehicle operator and the Traffic Flow Management (TFM )
Response Organization
o Due to the fact that orbital CST missions may need to be aborted anywhere
around the earth, a global alerting function has to include segregated foci of
the involved response organizations, from international down to regional or
even local reaction units.
This paper describes the integration of the above mentioned services in the Air Traffic
Management (ATM) information exchange concept of SWIM. It proposes an implementation
concept via the world wide use of Remote Tower Operations (RTO) for surveillance of safe
landings at spaceports far away from the launch/start site
Simulation of new Display Concepts for Air/Space Traffic Control Systems
A long track record on research on display concepts is available in the domain to assist the Air Traffic Controller in his situation awareness. Most of the concepts were designed to reduce Air Traffic Management (ATM) complexity with respect to traffic density, identification and resolution of conflict situations as well as to enhance the efficiency of the air transport system. The existing concepts mostly do not take into consideration air traffic and space traffic above flight level 500. Further on, higher speed and higher rates of decent of space vehicles are not fully considered. Also the operation of space vehicles at spaceports - which could be also passenger airports - has to be considered. Landing and ground operations can make use of modern remote tower installations (RTO), which will especially facilitate landing on remote sites or sites located away from operation centers and the related customers. For the implementation of future display concepts, a validation process is required. We discuss the assets of the DLR Air Transport Validation Center for life virtual constructive simulations and the methodology of the European Operation Concept Validation Methodology (EOCVM) of Eurocontrol. Results include the validation of 3D-Displays for enhanced situation awareness for new types of airspace users and a successful validation for RTO systems
Analysis of the Differences between Force Control and Feed Control Strategies during the Honing of Bores
AbstractHoning is a machining process that can economically produce very exact bores regarding form, geometry and surface quality. It is mainly used as the final finishing operation for ready made parts and typically conducted on the inner surface of a cylinder. Due to their specific surface structure which has a good ability to keep lubricants and a high wear resistance, honed parts usually serve as functional surfaces to guide moved parts. Today, the main fields for applications of honing technology can be found in most sectors of the metal working industry, e.g. the automotive industries, hydraulic and pneumatic manufacture and aircraft industries. During the long-stroke honing process the tool, equipped with one or several abrasive honing stones, is performing three overlaying movement components. These are a rotational movement, an oscillating stroke movement in axial direction and the radial feed movement of the honing stone. This feed movement is one of the decisive factors for the results of the honing process. It can be realized through feed control or, in a more recent approach, through force control strategies. By feed controlled honing, the position of the honing stone is changed in defined invariable steps in certain time intervals. In contrast, by force controlled honing the force of the honing stone against the wall of the workpiece is measured indirectly by a force sensor, which is located within the feed unit of the honing machine. A required force value is given and, if necessary, the honing stone is fed outwards to reach and maintain a constant cutting force throughout the honing process. This constant force is supposed to produce better results of the honing process in terms of geometric and form accuracy as well as surface structure. The presented research studies aim at improving process know-how to further increase the production accuracy and process repeatability. In a comparison between parts honed with the two different feeding strategies for the honing stone, force components and moments were analyzed and correlated to the phases of the process and several influencing parameters. In addition to the forces and moments measured during the honing process, the quality parameters of the honed parts have also been analyzed and compared
Examining trade-offs between social, psychological, and energy potential of urban form
Urban planners are often challenged with the task of developing design solutions which must meet multiple, and often contradictory, criteria. In this paper, we investigated the trade-offs between social, psychological, and energy potential of the fundamental elements of urban form: the street network and the building massing. Since formal methods to evaluate urban form from the psychological and social point of view are not readily available, we developed a methodological framework to quantify these criteria as the first contribution in this paper. To evaluate the psychological potential, we conducted a three-tiered empirical study starting from real world environments and then abstracting them to virtual environments. In each context, the implicit (physiological) response and explicit (subjective) response of pedestrians were measured. To quantify the social potential, we developed a street network centrality-based measure of social accessibility. For the energy potential, we created an energy model to analyze the impact of pure geometric form on the energy demand of the building stock. The second contribution of this work is a method to identify distinct clusters of urban form and, for each, explore the trade-offs between the select design criteria. We applied this method to two case studies identifying nine types of urban form and their respective potential trade-offs, which are directly applicable for the assessment of strategic decisions regarding urban form during the early planning stages
NAS Integration: CST and Air Traffic Insertion The Way Ahead
Differences in handling aircraft vs. spacecraft in ATM Challenges for CST ATM & STM Integration CST Integration in Airspace ERAU and DLR Collaboration EUROCONTROL - Network Manager DLR Remote Tower solutions for Spaceports ATM Integration of Space Vehicles in Europe / Germany SESAR Requirements & SWIM Spacecraft Flight Planning and Executio
Energy and Economic Performance of Solar Cooling Systems World Wide
AbstractSolar thermal cooling systems have been installed as pilot projects in most regions of the world, but due to the low number of total installations there is not yet much experience available about system sizing and design. To counter the lack of experience and to evaluate the potential of energy efficient solar cooling systems, a systematic system design study has been carried out covering most climatic regions worldwide. For each technology investigated, an energy optimized control strategy was developed which maximizes the primary energy efficiency. This control strategy was implemented in the simulation environment INSEL and system models were developed for a range of thermal cooling technologies and validated with operating experiences from different plants monitored by the authors.It could be shown that a reduction of nominal chiller power by 30% to 40% or more hardly effects the solar cooling fraction for most climates, but significantly increases the machine operating hours and thus improves the economics. The lower the nominal power of the chiller, the higher the recommended ratio of collector surface area per kW. For a given machine nominal power, solar cooling fractions increase with collector surface area until saturation is reached. Collector surface areas can be as high as 5 m2 to 10 m2 per kW with still increasing solar cooling fractions, but acceptable specific collector yield reduction. The economic optimum is reached for less solar cooling fraction and thus lower primary energy savings. Single effect absorption cooling systems easily reach 80% solar cooling fraction for all but very humid climates. Primary energy ratios can be over 3.0, depending on system design and cooling load data. CO2 and primary energy savings of 30 – 79% are achievable.The economic study showed that solar thermal cooling is more viable in hot climates than in moderate European climates. Annual costs strongly depend on the locations. The specific costs per kWh cooling in German locations vary between 0.25 and 1.01 €/kWh, in Spanish locations between 0.13 and 0.30 €/kWh. In hot climates like Jakarta and Riyadh the specific costs are as low as 0.09 to 0.15 €/kWh. Furthermore the maximum investment costs were calculated get a payback time of 10 years
Кінетика сумісного виділення цинку і нікелю з розбавлених електролітів
Досліджені закономірності виділення цінку, нікелю і цинк-нікелевого сплаву з розведених електролітів, що містять в якості лігандів амінокислоту та аміак. Найкращі технологічні параметри та якість покрить отримані при спільному вмісті у розчині обох лігандів. Запропонований електроліт характеризується високою стабільністю, є технологічним та екологічно безпечним.The mechanisms of zinc, nickel and zinc-nickel alloy deposition from diluted electrolytes, containing amino acid or ammonia as a ligand, were investigated. The very technological characteristics and coatings quality were obtained if the electrolyte contained both of the ligands. The suggested electrolyte is characterized by high stability, processibility and it is ecologically safe
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