457 research outputs found

    . Разработка цифровых алгоритмов управления приводами мехатронной системы реверсивной кле-ти толстолистового прокатного стана

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    Expanding the plate mill product range implies the improvement of control algorithms for the mechatronics control system drives of the reversing stands. The most important objectives include increasing the accuracy of geometric dimensioning and tolerancing, as well as improving the profile and surface flatness of rolled pro­ducts. The structure explaining the automatic ROLL-GAP CONTROL concept is provided, which allows controlling the thickness and gap between SMS-Demag AG rolls. This concept is implemented in the '5000' mill stand of Magnitogorsk Iron and Steel Works. The structural diagram of the automatic gauge control system (AGS) is presented. The functional diagram of the hydraulic gap control (HGC) system is presented, which includes a fast proportional control channel and a relatively slow integral position control channel. The principle of automatic thickness control is discussed, implemented in the automatic gauge control (AGC) system of the mill stand TCS controller. The diagram and dependences are prepared for the calculation of the nonlinear thickness controller parameters. The functions of the RAC regulator are described, intended for compensation of the tensile difference (gap spacing) at the mill stand sides. The dynamic impact compensation system functions are considered. The removal of the roll bending and deformation control signals is substantiated. The disadvantages of AGC are noted for sheets with a thickness below 10 mm. The most dangerous case is the tearing of metal fragments from the rear sheet side caused by the incorrect operation of the gauge control system. A method for hydraulic gap control is proposed based on the fast increase of the roll gap in the rear part of the rolled sheet during the last passage when rolling thin sheets. The results of experimental studies made on the '5000' mill are presented. The efficiency of the proposed control method has been confirmed. The oscillograms of signals are presented characterizing thickness variations. HGC and AGC systems with the proposed adjustments are proven to provide high-accuracy hydraulic position control and thickness control along the sheet length and width.При расширении сортамента продукции толстолистовых прокатных станов приобретает актуальность проблема совершенствования алгоритмов управления приводами мехатронной системы реверсивной клети. Важнейшими задачами являются повышение точности геометрических размеров, а также улучшение профиля и планшетности проката. Представлена структура, поясняющая концепцию ROLL-GAP CONTROLL автоматического регулирования толщины и зазора валков фирмы SMS-Demag AG. Данная концепция реализована на стане 5000 Магнитогорского металлургического комбината. Приведена структурная схема системы расчета и автоматического регулирования толщины (САРТ). Рассмотрена функциональная схема системы регулирования положения гидравлических нажимных устройств Hydraulic Gap Control (HGC), включающая быстродействующий канал пропорционального регулирования и относительно медленный канал интегрального регулирования положения. Рассмотрен принцип автоматического регулирования толщины, реализованный в ресурсе системы Automatic Gap Control (AGC) контроллера TCS клети. Представлены схема и зависимости для вычисления коэффициентов нелинейного регулятора толщины. Отмечены функции RAC-регулятора, предназначенного для компенсации разницы растяжений (перекоса) зазора по сторонам клети. Рассмотрены функции системы динамической компенсации возмущающих воздействий. Обосновано исключение сигналов коррекции противоизгиба и деформации валков. Отмечены недостатки САРТ при прокатке листов толщиной менее 10 мм. Наболее опасным является отрыв фрагментов металла от хвостовой части, вызванный некорректной работой системы задания толщины. Предложен способ управления гидравлическими нажимными устройствами, суть которого заключается в быстродействующем увеличении межвалкового зазора на «хвосте» раската в последнем проходе при прокатке тонких листов. Представлены результаты экспериментальных исследований, выполненных на стане 5000. Подтверждена техническая эффективность внедрения предложенного способа управления. Рассмотрены осциллограммы сигналов, характеризующих разнотолщинность. Доказано, что при предложенных настройках систем HGC и AGC обеспечивается высокая точность регулирования положения нажимных устройств и толщины по длине и ширине листа

    Liquid Rocket Booster (LRB) for the Space Transportation System (STS) systems study, volume 2

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    The Liquid Rocket Booster (LRB) Systems Definition Handbook presents the analyses and design data developed during the study. The Systems Definition Handbook (SDH) contains three major parts: the LRB vehicles definition; the Pressure-Fed Booster Test Bed (PFBTB) study results; and the ALS/LRB study results. Included in this volume are the results of all trade studies; final configurations with supporting rationale and analyses; technology assessments; long lead requirements for facilities, materials, components, and subsystems; operational requirements and scenarios; and safety, reliability, and environmental analyses

    Annual report of the National Advisory Committee for Aeronautics (34th). administrative report including Technical Report nos. 892 to 921

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    Report includes the National Advisory Committee for Aeronautics letter of submittal to the President, summaries of the committee's activities and research accomplished, bibliographies, and financial report

    Access to space

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    The goal of this conceptual design was to devise a reusable, commercially viable, single-stage-to-orbit vehicle. The vehicle has the ability to deliver a 9100 kg (20,000 lb) payload to a low earth orbit of 433 km to 933 km (250 n.mi. - 450 n.mi.). The SSTO vehicle is 51 meters in length and has a gross takeoff mass of 680,400 kg (1,500,000 lb). The vehicle incorporates three RD-701 engines for the main propulsion system and two RL-10 engines for the orbital maneuvering system. The vehicle is designed for a three day stay on orbit with two crew members

    29th IAPRI Symposium on Packaging 2019:Proceedings

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    Proceedings of the 8th Annual Summer Conference: NASA/USRA Advanced Design Program

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    Papers presented at the 8th Annual Summer Conference are categorized as Space Projects and Aeronautics projects. Topics covered include: Systematic Propulsion Optimization Tools (SPOT), Assured Crew Return Vehicle Post Landing Configuration Design and Test, Autonomous Support for Microorganism Research in Space, Bioregenerative System Components for Microgravity, The Extended Mission Rover (EMR), Planetary Surface Exploration MESUR/Autonomous Lunar Rover, Automation of Closed Environments in Space for Human Comfort and Safety, Walking Robot Design, Extraterrestrial Surface Propulsion Systems, The Design of Four Hypersonic Reconnaissance Aircraft, Design of a Refueling Tanker Delivering Liquid Hydrogen, The Design of a Long-Range Megatransport Aircraft, and Solar Powered Multipurpose Remotely Powered Aircraft

    INTER-ENG 2020

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    These proceedings contain research papers that were accepted for presentation at the 14th International Conference Inter-Eng 2020 ,Interdisciplinarity in Engineering, which was held on 8–9 October 2020, in Târgu Mureș, Romania. It is a leading international professional and scientific forum for engineers and scientists to present research works, contributions, and recent developments, as well as current practices in engineering, which is falling into a tradition of important scientific events occurring at Faculty of Engineering and Information Technology in the George Emil Palade University of Medicine, Pharmacy Science, and Technology of Târgu Mures, Romania. The Inter-Eng conference started from the observation that in the 21st century, the era of high technology, without new approaches in research, we cannot speak of a harmonious society. The theme of the conference, proposing a new approach related to Industry 4.0, was the development of a new generation of smart factories based on the manufacturing and assembly process digitalization, related to advanced manufacturing technology, lean manufacturing, sustainable manufacturing, additive manufacturing, and manufacturing tools and equipment. The conference slogan was “Europe’s future is digital: a broad vision of the Industry 4.0 concept beyond direct manufacturing in the company”

    Aeronautical Engineering: A continuing bibliography with indexes, supplement 137, July 1981

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    This bibliography lists 483 reports, articles, and other documents introduced into the NASA scientific and technical information system in June 1981

    Mechanical Engineering

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    The book substantially offers the latest progresses about the important topics of the "Mechanical Engineering" to readers. It includes twenty-eight excellent studies prepared using state-of-art methodologies by professional researchers from different countries. The sections in the book comprise of the following titles: power transmission system, manufacturing processes and system analysis, thermo-fluid systems, simulations and computer applications, and new approaches in mechanical engineering education and organization systems

    Well P&A Tubing Compaction Method Evaluation and Modelling

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    Master's thesis in Petroleum engineeringThe number of aged fields in the North Sea is increasing, and in few years, and there will be a significant increase in number of wells that need to be permanently plugged and due to low oil prices and other reasons, there is a push from the industry to reduce the cost of P&A operations as much as possible, and using rig-less equipment for P&A has proven to be a reliable alternative to drilling rigs, but this solution requires the development of new technologies to overcome the challenges that come up with it. The presence of tubing in the area where the permeant plug should be set is still a thorny issue for P&A rig-less operation for many reasons. Recently there are many approaches for removing tubing in place without pulling it to surface, one of these alternative ideas is downhole tubing disposal (DHTD). The main scope of this thesis is to give an insight into DHTD method, its advantages and the challenges to translate this idea into practice. In this work as well, different approaches are incorporated to estimate the required tubing crushing force, including FEM, analytical estimation and experimental work. Results are reported for an analytical estimation and FEM (ABAQUS) analysis of a slotted tubular subjected to compression axial load. The results showed different kinds of correlations with experimental test data. On the other hand, they showed that FEM is a powerful method to solve this kind of problems
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