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1
Lodewyks, Johann, and Pascal Zurbrügg. "Decentralized energy-saving hydraulic concepts for mobile working machines." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-199996.
Повний текст джерелаАнотація:
The high price of batteries in working machines with electric drives offer a potential for investment in energy-saving hydraulic systems. The decentralized power network opens up new approaches for hydraulic- and hybrid circuits. In addition, the regeneration of energy can be used at any point of the machine. For the example of an excavator arm drive with a double cylinder two compact hydraulic circuits are presented, which relieve a central hydraulic system.
2
Sagström, Johan. "Streamlined LCA model and complete assessment of a hydraulic drive system." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-217801.
Повний текст джерелаАнотація:
This master thesis was commissioned by Bosch Rexroth AB and carried out over the course of 20 weeks between January and May 2017. The company produces hydraulic drive systems for different industrial applications, mostly for rotating heavy loads under constant, low speed and high torque. The products have a long life span and thus, optimizing the design of their products can have a considerable impact in terms of energy efficiency and environmental performance. In order to gain a better understanding of what role individual parts of the system have in terms of sustainability and to further investigate the entire life-cycles and environmental footprints of their products, Bosch Rexroth looked to the Life Cycle Assessment (LCA) method. There were two different major aims to this thesis project. The first aim was to provide Bosch Rexroth with in-depth knowledge around how their product systems perform from an environmental point of view, and more specifically one particular hydraulic drive. The second aim was to develop a tool tailor-made for Bosch Rexroth, capable of delivering simplified LCAs in a quick and easy fashion. The purpose of the tool was to assist Bosch Rexroth in decisionmaking during product development. In addition, the simplified tool should come with an interface easy to understand and use. The study was done according to a life cycle assessment approach and followed applicable international standards ISO 14040 and 14044. The LCA was simulated in the SimaPro 8 software, which was also used for all calculations including impact assessment according to the ReCiPe methodology. The results of the LCA were considered stable and representative for a specific case study of a hydraulic drive in operation at a paper mill in Sweden. The results from the simplified LCA model were considered satisfactory and within desired tolerance. One of the key conclusions of the thesis was a take-back system for some of the parts of the hydraulic drive could benefit the environment to a large extent, which should encourage Bosch Rexroth to examine such possibilities further.Detta examensarbete genomfördes på uppdrag av Bosch Rexroth AB under 20 veckor mellan januari och maj 2017. Företaget producerar hydrauliska drivsystem för många olika industriella applikationer, främst för att rotera tunga laster under konstant, låg hastighet och högt vridmoment. Produkterna har en lång livslängd vilket innebär att optimering av designen kan ha en betydande inverkan på energieffektivitet och miljöprestanda. Detta examensarbete utfördes i syfte att ge Bosch Rexroth en bättre förståelse för vilken roll enskilda delar av systemet har när det gäller miljöpåverkan. Projektet hade två huvudmål. Det första målet var att ge Bosch Rexroth en djupare kunskap om hur deras produktsystem påverkar miljön, och mer specifikt en särskild hydraulisk motor. Det andra målet var att utveckla ett verktyg som var skräddarsytt för Bosch Rexroth och som kunde leverera förenklade livscykelanalyser på ett snabbare och enklare sätt än den som avhandlas i denna rapport. Dessa förenklade analyser skulle sedan kunna användas som beslutsunderlag i anknytning till produktutveckling. Utöver det skulle det skräddarsydda verktyget ha ett grafiskt gränssnitt som skulle vara lätt att förstå och använda. Livscykelanalysen gjordes enligt gällande internationella standarder ISO 14040 och 14044. Analysen simulerades i mjukvaran SimaPro 8, som också användes för alla påverkansberäkningar och konsekvensbedömning enligt ReCiPe-metoden. Resultaten ansågs stabila med avseende på den genomförda fallstudien av en motor i drift vid ett pappersbruk i Sverige. Resultaten från den förenklad LCA-modellen betraktades som tillfredsställande och inom den önskade toleransen. En av de viktigaste slutsatserna av arbetet var att ett strukturerat återanvändningssystem för vissa av detaljerna i motorerna skulle kunna ge en potentiellt mycket fördelaktig miljömässig påverkansförbättring. Bosch Rexroth uppmuntras därför att vidare undersöka möjligheterna med ett sådant system, både i Sverige och på de globala marknaderna.
3
Shimizu, Juri, Takuya Otani, Kenji Hashimoto, and Atsuo Takanishi. "Simulation of an interlocking hydraulic direct-drive system for a biped walking robot." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71091.
Повний текст джерелаАнотація:
Biped robots with serial links driven by an electric motor experience problems because the motor and transmission are installed in each joint, causing the legs to become very heavy. Previous solutions involved robots using servo valves, a type of highly responsive proportional valve. However, high supply pressure is necessary to realize high responsiveness and the resulting energy losses are large. To address this problem, we proposed a hydraulic direct-drive system in which the pump controls the cylinder meter-in flow, while a proportional valve controls the meter-out flow. Furthermore, our hydraulic interlocking drive system connects two hydraulic direct-drive systems for biped humanoid robots and concentrates the pump output on one side cylinder. The meter-in flow rate of the other side cylinder is controlled by the meter-out flow rate of the cylinder on which the pump is concentrated. A comparison of the walking simulation performance with that of the conventional independent system shows that our proposed system reduces the motor output power by 24.3%. These results prove the feasibility of constructing a two-legged robot without having to incorporate highly responsive servo valves.
4
Fernandes, Rita. "Efficient Volvo Bus Cooling System,Using Electrical Fans : A comparison between hydraulic and electrical fans." Thesis, KTH, Kraft- och värmeteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-155901.
Повний текст джерелаАнотація:
Economical and environmental factors together with energy policies towards more efficient systemsare the driving force for the development of the vehicle industry. Significant changes have beenmade to fulfill new emissions legislation but the basic internal combustion vehicle architecture hasbeen kept. New emission treatment systems that increase the thermal loading of the cooling systemhad been added within the same package envelope as before, which means less space to place coolingfans and a greater need for airflow. Changes in the cooling system, namely the replacement of thehydraulic fan drive system by electrical fans is one of the energy efficient alternatives for severalcity buses under certain environments, like the ”typical red city buses”, well-known in the UnitedKingdom. In this thesis study, hydraulic fans are compared with electrical fans and a road-mapof the benefits and drawbacks of the two systems is developed, based on real traffic performanceperformance data and the results of existing simulations and tests. In addition, new simulations arepresented in order to find the most efficient design for the cooling system as well as a comparisonof these results with previous ones. This road map will be used later by Volvo-Buses Group as atool to better understand in which circumstances electrical fans can be beneficial, in terms of fuelconsumption, noise production, cooling performance, control of the fans and associated costs.
5
Lammers, Zachary A. "Thermal Management of Electromechanical Actuation System for Aircraft Primary Flight Control Surfaces." University of Dayton / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1399021324.
Повний текст джерела
6
Бурлига, Михайло Борисович. "Розвиток методів розрахунку та вибір раціональних схем двопотокових безступінчастих гідрооб'ємно-механічних трансмісій колісних тракторів". Thesis, НТУ "ХПІ", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/35538.
Повний текст джерелаАнотація:
Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.22.02 – автомобілі та трактори. Національний технічний університет "Харківський політехнічний інститут", Харків, 2017.
Дисертація присвячена розвитку методів розрахунку для аналізу робочих параметрів безступінчастих ГОМТ і їх основних елементів ГОП, прогнозуванню техніко-економічних показників машинно-тракторного агрегату для визначення раціональних схемних рішень ГОМТ. Актуальність роботи полягає у необхідності забезпечення конкурентоспроможності вітчизняних тракторів. Здійснено аналіз роботи двопотокових ГОМТ колісних тракторів зарубіжних аналогів. Уточнено на підставі новітніх експериментальних даних щодо втрат і ККД математичну модель об’ємних аксіально-поршневих гідромашин, як основних елементів тракторних ГОМТ. Розроблено алгоритм і обчислювальну процедуру щодо встановлення взаємно однозначної відповідності між робочими параметрами, втратами і ККД ГОП в прямому і зворотному потоках потужності крізь ГОП під час їх роботи у складі двопотокових ГОМТ. Вперше розроблено розрахунково-теоретичну методику і програмну реалізацію з визначення параметрів ГОП, ГОМТ і основних техніко-економічних показників МТА з урахуванням режимів циркуляції потужності, втрат в ГОП, ГОМТ і буксування трактора для аналізу і прогнозування характеристик альтернативних тракторних ГОМТ та наукового обґрунтування найраціональнішої трансмісії для конкретного трактора. Вперше вирішено задачу побудови універсальних характеристик тракторів з ГОМТ і візуалізації робочих параметрів ГОМТ у всьому діапазоні експлуатаційних режимів трактора для порівняння альтернативних схемних рішень ГОМТ і вибору найраціональнішого з них. Побудовано універсальні характеристики першого в Україні трактора ХТЗ-21021 з ГОМТ-1С розробки НТУ "ХПІ" і АТ "ХТЗ". За результатами чисельного і натурного експериментів зроблено висновок, що математичні моделі й запропоновані методики є адекватними і спрямованими на підвищення ефективності та конкурентоспроможності вітчизняних тракторів.Thesis for Scientific degree of candidate of technical sciences, specialty 05.22.02 – vehicles and tractors. National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2017. The work is devoted to solving the technical problem of development of calculation methods and choice of rational schemes of dual path hydraulic volume mechanical transmission (HVMT) wheeled tractors, which allows you to select the optimal scheme HVMT at the design stage. Actuality of work consists in the necessity of providing of competitiveness of Ukraine tractors. The analysis of work of the dual path HVMT tractors of foreign analogues is carried out. Refined mathematical model of hydrostatic axial-piston hydraulic machines as the main HVMT elements identity-based loss coefficients with the latest experimental data loss and coefficient of performance (COP). The algorithm and the computational procedure for the establishment of a oneto-one correspondence between the operating parameters and the efficiency of hydraulic drive system (HDS) losses in forward and reverse flow of power through the HDS for her work in the dual path tractor HVMT. Calculation-theoretical methodology and her programmatic realization is first worked out for determination of HDS parameters, dual path HVMT and basic technical and economic indexes of tractor-aggregate taking into account the modes of circulation of power, losses in HDS, HVMT and skidding of tractor for an analysis and prognostication of descriptions alternative tractor HVMT and scientific ground of the most rational transmission for a certain tractor. The problem of construction of universal descriptions of tractor is first set and decided with dual path HVMT. Original solution of task offers on visualization of kinematics, power and power parameters of dual path HVMT of the perspective Ukrainian tractors in all range of their operating modes as an important criterion for comparison of alternative schematics of HVMT. Universal descriptions of first in Ukraine and on post-soviet space of tractor of XTZ-21021 from stepless HVMT-1S development of NТU "KhPI" and propulsion MODULE of "XTZ" are built. Results numeral and natural experiments allow to draw conclusion, that the calculation-theoretical methodologies and constituents of them worked out in dissertation mathematical models are adequate and directed to on an increase efficiency and competitiveness of the Ukrainian tractors.
7
Бурлига, Михайло Борисович. "Розвиток методів розрахунку та вибір раціональних схем двопотокових безступінчастих гідрооб'ємно-механічних трансмісій колісних тракторів". Thesis, НТУ "ХПІ", 2018. http://repository.kpi.kharkov.ua/handle/KhPI-Press/35536.
Повний текст джерелаАнотація:
Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.22.02 – автомобілі та трактори. Національний технічний університет "Харківський політехнічний інститут", Харків, 2017.
Дисертація присвячена розвитку методів розрахунку для аналізу робочих параметрів безступінчастих ГОМТ і їх основних елементів ГОП, прогнозуванню техніко-економічних показників машинно-тракторного агрегату для визначення раціональних схемних рішень ГОМТ. Актуальність роботи полягає у необхідності забезпечення конкурентоспроможності вітчизняних тракторів. Здійснено аналіз роботи двопотокових ГОМТ колісних тракторів зарубіжних аналогів. Уточнено на підставі новітніх експериментальних даних щодо втрат і ККД математичну модель об’ємних аксіально-поршневих гідромашин, як основних елементів тракторних ГОМТ. Розроблено алгоритм і обчислювальну процедуру щодо встановлення взаємно однозначної відповідності між робочими параметрами, втратами і ККД ГОП в прямому і зворотному потоках потужності крізь ГОП під час їх роботи у складі двопотокових ГОМТ. Вперше розроблено розрахунково-теоретичну методику і програмну реалізацію з визначення параметрів ГОП, ГОМТ і основних техніко-економічних показників МТА з урахуванням режимів циркуляції потужності, втрат в ГОП, ГОМТ і буксування трактора для аналізу і прогнозування характеристик альтернативних тракторних ГОМТ та наукового обґрунтування найраціональнішої трансмісії для конкретного трактора. Вперше вирішено задачу побудови універсальних характеристик тракторів з ГОМТ і візуалізації робочих параметрів ГОМТ у всьому діапазоні експлуатаційних режимів трактора для порівняння альтернативних схемних рішень ГОМТ і вибору найраціональнішого з них. Побудовано універсальні характеристики першого в Україні трактора ХТЗ-21021 з ГОМТ-1С розробки НТУ "ХПІ" і АТ "ХТЗ". За результатами чисельного і натурного експериментів зроблено висновок, що математичні моделі й запропоновані методики є адекватними і спрямованими на підвищення ефективності та конкурентоспроможності вітчизняних тракторів.Thesis for Scientific degree of candidate of technical sciences, specialty 05.22.02 – vehicles and tractors. National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2017. The work is devoted to solving the technical problem of development of calculation methods and choice of rational schemes of dual path hydraulic volume mechanical transmission (HVMT) wheeled tractors, which allows you to select the optimal scheme HVMT at the design stage. Actuality of work consists in the necessity of providing of competitiveness of Ukraine tractors. The analysis of work of the dual path HVMT tractors of foreign analogues is carried out. Refined mathematical model of hydrostatic axial-piston hydraulic machines as the main HVMT elements identity-based loss coefficients with the latest experimental data loss and coefficient of performance (COP). The algorithm and the computational procedure for the establishment of a oneto-one correspondence between the operating parameters and the efficiency of hydraulic drive system (HDS) losses in forward and reverse flow of power through the HDS for her work in the dual path tractor HVMT. Calculation-theoretical methodology and her programmatic realization is first worked out for determination of HDS parameters, dual path HVMT and basic technical and economic indexes of tractor-aggregate taking into account the modes of circulation of power, losses in HDS, HVMT and skidding of tractor for an analysis and prognostication of descriptions alternative tractor HVMT and scientific ground of the most rational transmission for a certain tractor. The problem of construction of universal descriptions of tractor is first set and decided with dual path HVMT. Original solution of task offers on visualization of kinematics, power and power parameters of dual path HVMT of the perspective Ukrainian tractors in all range of their operating modes as an important criterion for comparison of alternative schematics of HVMT. Universal descriptions of first in Ukraine and on post-soviet space of tractor of XTZ-21021 from stepless HVMT-1S development of NТU "KhPI" and propulsion MODULE of "XTZ" are built. Results numeral and natural experiments allow to draw conclusion, that the calculation-theoretical methodologies and constituents of them worked out in dissertation mathematical models are adequate and directed to on an increase efficiency and competitiveness of the Ukrainian tractors.
8
Pokorný, Jan. "Interakce mobilních pracovních strojů a pojížděného podloží." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-233912.
Повний текст джерелаАнотація:
This dissertation thesis is concerning with an interaction between mobile working machines and rolled surfaces. Machines and their constructions parts behavior were observed. There are some machines that can change state of surface. And due to these change of surface the machine is in different conditions for drive and also for works. The interaction of working machines and rolled surfaces was categorized in this work and for each category here is a methodic work flow for solution of various cases. Three examples are described in this work. Some simulating programs were used for all cases and therefore there is a methodic work flow for creating and simulating of models. Three described examples include a complex solution of hydraulic drive for vibration exciter of vibration roller, small cleaner of canalizations with aim on load case to frame of this cart. The third example describes solution of undercarriage frames of agricultural semi-trailers. This example is the most extensive chapter from this work due to including of marketing research at the beginning of development and also verification of simulated results with results from real prototype tests at the end of development of these undercarriage frames.
9
Gerec, Matúš. "Pohonný a brzdový systém motorového vozu železnice pro muzeum průmyslových železnic." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318852.
Повний текст джерелаАнотація:
This thesis deals with the design of the propulsion and braking system for narrow gauge railcar. It contains the design of hydrostatic drive system with closed-loop hydraulic circuit. Then thesis describes the concept of propulsion system placement in the frame of the railcar and design of the braking system.
10
Онуцький, Віталій Григорович, Віталій Олегович Колодій, Vitaly Onutsky та Vitaly Kolodiy. "Розроблення автоматизованого стенду для дослідження вібростійкості електрообладнання". Master's thesis, Тернопільський національний технічний університет ім. І. Пулюя, Факультет прикладних інформаційних технологій та електроінженерії, Кафедра автоматизації технологічних процесів і виробництв, 2021. http://elartu.tntu.edu.ua/handle/lib/36718.
Повний текст джерелаАнотація:
Робота виконана на кафедрі автоматизації технологічних процесів і виробництв факультету прикладних інформаційних технологій та електроінженерії Тернопільського національного технічного університету імені Івана Пулюя Міністерства освіти і науки України. Захист відбудеться «23» грудня 2021р. о 9.00год. на засіданні екзаменаційної комісії №22 у Тернопільському національному технічному університеті імені Івана Пулюя.В кваліфікаційній роботі подано результати аналізу та синтезу системи автоматизованого керування стендом для вібраційних досліджень електротехнічних установок та агрегатів. Дослідження проводились з використанням методів імітаційного моделювання та статистичного аналізу. У результаті проведеного дослідження виконано умови щодо стійкості та якості роботи розробленої системи. Розроблено математичні моделі автоматизованої системи управління та доведено її достовірність.
The qualification work presents the results of analysis and synthesis of automated stand control system for vibration studies of electrical installations and units. The research was conducted using simulation methods and statistical analysis. As a result of the study, the conditions for the stability and quality of the developed system were met. Mathematical models of the automated control system are developed and its reliability is proved.
Анотація 4 Перелік основних позначень та скорочень 7 Вступ 8 1 Аналітична частина 10 1.1 Відпрацювання міцності електронної техніки методом дослідження вібростійкості 10 1.2 Системи для дослідження вібростійкості промислової продукції фірми Bruel & Kjaer 11 1.3 Системи дослідження вібростійкості компанії LDS 16 1.4 Принцип дії і характеристики сучасних вібродатчиків 17 2 Технологічна частина 30 2.1 Статистичний аналіз систем автоматичного управління 30 2.2 Детермінована та статистична ідентифікація САУ 40 2.3 Вибір і обгрунтування аналогів розроблюваної автоматизованої системи 49 3 Конструкторська частина 53 3.1 Особливості та область призначення установок для дослідження вібростійкості 53 3.2 Аналітичне дослідження системи і створення її математичної моделі 59 3.3 Розроблення засобів безпечної експлуатації віброустановки 65 4 Науково-дослідна частина 71 4.1 Статистична лінеаризація при дослідженні експлуатаційних режимів роботи слідкуючого вібраційного стенду 71 4.2 Результати моделювання та дослідження створених моделей у середовищі MathLab 80 4.3 Перевірка достовірності моделі системи згідно еталонного управляючого сигналу 84 5 Спеціальна частина 90 5.1 Розробка креслень в системі AutoCAD 90 5.2 Використання пакету прикладних програм MathLab для проведення дослідження 93 6 Охорона праці та безпека в надзвичайних ситуаціях 95 6.1 Заходи з охорони праці 95 6.2 Заходи з безпеки в надзвичайних ситуаціях 103 Висновки 109 Перелік посилань 110
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Бартош, Тарас Тарасович, та Taras Bartosh. "Інформаційно-вимірювальна система установки для розсортування деталей за внутрішнім діаметром отворів". Master's thesis, ТНТУ ім. І. Пулюя, 2020. http://elartu.tntu.edu.ua/handle/lib/33691.
Повний текст джерелаАнотація:
Розроблено інформаційно-вимірювальну систему установки для розсортування деталей за внутрішнім діаметром отворів. В даній кваліфікаційній роботі магістра було розроблено та спроектовано механізми подачі та розсортування, механізм подачі деталей. Проведено дослідження похибки вимірювання даного пристрою. Проаналізовано та описано технічні вимого до метеорологічних параметрів системи. Описано роботу приладу, його структурні та принципову схеми. Розраховано параметри схеми.The information-measuring system of installation for sorting of details on internal diameter of apertures is developed. In this qualification work of the master the mechanisms of giving and sorting, the mechanism of giving of details have been developed and designed. A study of the measurement error of this device carried out. The technical requirements for the meteorological parameters of the system are analyzed and described. The operation of the device, its structural and schematic diagrams are described. Scheme parameters are calculated.
Вступ...7 1 Аналітична частина...8 1.1 Аналіз аналогів...8 1.2 Результати патентного пошуку ...13 2 Основна частина...17 2.1 Вимоги до роботи приладу ...17 2.2 Схема та принцип роботи приладу ...17 2.3 Механізм подачі деталей та розсортування ...19 2.4 Механізм подачі деталей...20 2.5 Механізовані приводи установок...22 2.6 Побудова циклограми роботи установки ...25 2.7 Аналіз об’єкту вимірювання і технічних вимог до метрологічних параметрів системи...31 2.8 Аналіз і оцінка похибки схеми ...32 2.9 Похибка установки ...35 2.10 Повірка пристрою ...38 2.11 Проведення повірки...39 3 Науково-дослідна частина...41 3.1 Розрахункова частина...41 4 Спеціальна частина ...51 4.1 Опис роботи приладу...51 4.2 Опис структурної схеми і алгоритму роботи електричної схеми...55 4.3 Опис роботи принципової схеми приладу ...57 4.4 Розрахунок параметрів схеми...58 4.5 Електронна принципова схема ...62 4.6 Опис роботи принципової схеми ...63 4.7 Опис роботи програми ...67 5 Охорона праці та безпека в надзвичайних ситуаціях...69 5.1 Охорона праці...69 5.1.1 Заходи з охорони праці при виконанні монтажних робіт ...69 5.1.2 Санітарно-гігієнічне та побутове обслуговування робітників...70 5.1.3 Розрахунок штучного освітлення...70 5.2 Безпека в надзвичайних ситуаціях...75 5.2.1 Організація безпеки в надзвичайних ситуаціях при автоматизації технологічного процесу ...75 5.2.2 Створення цивільного захисту на ОГД ...77 5.2.3 Галузеві системи управління охороною праці. Мета та принципи функціонування...82 ЗАГАЛЬНІ ВИСНОВКИ ДО КВАЛІФІКАЦІЙНОЇ РОБОТИ ...85 ПЕРЕЛІК ПОСИЛАНЬ...86 ДОДАТКИ...
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透, 山下, та Tohru Yamashita. "遮断器用油圧操作装置の動作時間安定化に関する研究". Thesis, https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13045046/?lang=0, 2017. https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13045046/?lang=0.
Повний текст джерелаАнотація:
電力用遮断器の油圧操作装置において，油圧回路内の気泡が操作装置の動作に及ぼす悪影響を解消するために，新しい油圧回路方式である常時高圧安定回路方式を提案し，油圧回路内の流れおよび可動部の定式化と解析および実測を行った．本方式の動作特性と動作安定性，ピストンの制動特性，複数の油圧操作装置の駆動特性について検討し，本方式が有効かつ安定的に機能することを確認した．以上により，油圧操作装置の動作時間安定化技術を開発することができた．We proposed and studied a hydraulic operation stabilizing system for a hydraulic operating device of a circuit breaker to eliminate the influence of air bubbles created in hydraulic fluid. We formulated the flow of hydraulic circuit and the motion of moving parts, which were numerically simulated and experimentally confirmed. We confirmed that this stabilizing system functioned effectively and stably through the investigation: operation characteristics and stability of the stabilizing system, braking characteristics of a piston-dashpot system and operation characteristics of two hydraulic operating devices. Based on the results, we could perform an engineering development for stabilizing operation time of the hydraulic operating device.
博士(工学)
Doctor of Philosophy in Engineering
同志社大学
Doshisha University
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Stewart, James. "The application of artificial intelligence to fault detection in hydraulic cylinder drive systems." Thesis, Cardiff University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284493.
Повний текст джерелаАнотація:
An expert system approach to fault diagnosis of fluid power circuits is considered with emphasis on leakage flow detection, and for valvecontrolled cylinders. Two test rigs were used, one being a solenoid-valve controlled cylinder operated directly and in an open-loop mode, the other being a servo-valve controlled actuator operated by microcomputer and in a closed-loop mode. Both systems incorporated the use of on-line dynamic data, and for the closed-loop case operation and fault diagnosis was integrated into an automated procedure. Flow leakage detection was considered a priority, and an alternative approach using displaced volumes was successfully implemented. The research work concentrated initially on the use of an expert system and the establishment of an appropriate knowledge base using a hybrid reasoning approach. This approach was found to be excellent for single-fault conditions but could not differentiate components of multiple-fault conditions, other than that they existed, due to the use of a minimum number of flow sensors. Additional techniques were then considered for the closed-loop control system utilising steady-state position error, time series analysis, and Artificial Neural Networks. It was found that the consideration of steady-state error gave information complementary to the existing knowledge base but could not give any additional information. The use of an artificial neural network was found to give more information with regards to multiple-fault conditions, resulting in a percentage probability for each fault combination.
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Frerichs, Ludger, and Karl Hartmann. "Efficient and high performing hydraulic systems in mobile machines." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-200364.
Повний текст джерелаАнотація:
Hydraulic systems represent a crucial part of the drivetrain of mobile machines. The most important drivers of current developments, increasing energy efficiency and productivity, are leading to certain trends in technology. On a subsystem level, working hydraulics are utilizing effects by improving control functions and by maximum usage of energy recovery potential. Independent metering and displacement control, partly in combination with hybrid concepts, are the dominating approaches. Traction drives gain advantage from optimized power split transmissions, which consequently are being used in a growing number of applications. On the level of components, increase of efficiency and dynamics as well as power density are important trends. Altogether, design of systems and components is more and more based on modular concepts. In this sense, among others, sensors and control elements are being integrated to actuators; electric and hydraulic technology is being merged. In order to achieve maximum efficiency and performance of the entire machine, control of hydraulics has to include the whole drivetrain and the entire mobile machine in its application. In modern words, mobile hydraulic systems are a part of cyber physical systems.
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Minav, Tatiana, Jani Heikkinen, Soumadipta Pyne, Sami Haikio, Juha Nykanen, and Matti Pietola. "Analysis of novel zonal two-cylinder actuation system for heavy loads." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71078.
Повний текст джерелаАнотація:
Climate change and economic opportunities motivate investigating electric distributed power for working hydraulics in non-road mobile machinery (NRMM) instead of conventional hydraulics. This recent method allows significant energy savings in hydraulic systems, which was demonstrated previously by many independent studies. In this study, zonal hydraulics (as electrically distributed) are realized with direct driven hydraulics drive (DDH) units. Unlike conventional hydraulic drives the DDH units are disconnected from the engine (main prime mover) and distributed throughout the system. In a DDH unit, a single fixed displacement pump/motor with a speed-controlled electric servomotor directly controls the flow. The aim of this paper is to determine functionality of this new two-cylinder DDH-system in a lifting work cycle (or a swerve motion of the work machine). For this purpose, a model was created to investigate performance of the new test rig Dolores. The results of the simulation model will be utilized in future research to discover and compare other alternatives for working hydraulics architectures.
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賴志強 and Chi-keung Lai. "Dynamic response of a variable speed pumping system." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1994. http://hub.hku.hk/bib/B31212360.
Повний текст джерела
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Lai, Chi-keung. "Dynamic response of a variable speed pumping system /." Hong Kong : University of Hong Kong, 1994. http://sunzi.lib.hku.hk/hkuto/record.jsp?B20666305.
Повний текст джерела
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Miao, Miao. "Molecular dynamics simulation of electroosmotic & pressure driven flows in nanochannels." Online access for everyone, 2007. http://www.dissertations.wsu.edu/Thesis/Summer2007/m_miao_071907.pdf.
Повний текст джерела
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Laudensack, Christian [Verfasser]. "Design and System Analyses of Canned Switched Reluctance Drives for Hydraulic Pump Applications / Christian Laudensack." Aachen : Shaker, 2016. http://d-nb.info/1118258894/34.
Повний текст джерела
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Palavicino, Pablo Castro, Bulent Sarlioglu, Dheeraj Bobba, Woongkul Lee, and Tatiana Minav. "Electrification of hydraulic systems using highefficiency permament magnet motors." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71116.
Повний текст джерелаАнотація:
In this paper, electrification of hydraulic systems is proposed using high-efficiency permanent magnet (PM) motors and wide bandgap power electronic drives. Direct driven hydraulics (DDH) is selected because of its higher efficiency compared to other conventional technologies such as valve-controlled systems. The DDH is directly driven by a servomotor. The ratings and design guidelines for a servomotor used in DDH applications are provided in this paper. Specifically, a surface permanent magnet synchronous machine (SPMSM) is designed. Finally, a state-of-the-art inverter using silicon carbide wide bandgap devices are designed for high performance operation.
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Comella, Laura [Verfasser], and Thomas [Akademischer Betreuer] Bauernhansl. "Position sensor and control system for micro hydraulic drives in surgical instruments / Laura Comella ; Betreuer: Thomas Bauernhansl." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2019. http://d-nb.info/1206183993/34.
Повний текст джерела
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Absalyamova, Viktoriya. "Energy Analysis within Industrial Hydraulics and Correspondent Solar PV System Design." Thesis, Högskolan Dalarna, Maskinteknik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:du-5099.
Повний текст джерелаАнотація:
Energy efficiency and renewable energy use are two main priorities leading to industrial sustainability nowadays according to European Steel Technology Platform (ESTP). Modernization efforts can be done by industries to improve energy consumptions of the production lines. These days, steel making industrial applications are energy and emission intensive. It was estimated that over the past years, energy consumption and corresponding CO2 generation has increased steadily reaching approximately 338.15 parts per million in august 2010 [1]. These kinds of facts and statistics have introduced a lot of room for improvement in energy efficiency for industrial applications through modernization and use of renewable energy sources such as solar Photovoltaic Systems (PV).The purpose of this thesis work is to make a preliminary design and simulation of the solar photovoltaic system which would attempt to cover the energy demand of the initial part of the pickling line hydraulic system at the SSAB steel plant. For this purpose, the energy consumptions of this hydraulic system would be studied and evaluated and a general analysis of the hydraulic and control components performance would be done which would yield a proper set of guidelines contributing towards future energy savings. The results of the energy efficiency analysis showed that the initial part of the pickling line hydraulic system worked with a low efficiency of 3.3%. Results of general analysis showed that hydraulic accumulators of 650 liter size should be used by the initial part pickling line system in combination with a one pump delivery of 100 l/min. Based on this, one PV system can deliver energy to an AC motor-pump set covering 17.6% of total energy and another PV system can supply a DC hydraulic pump substituting 26.7% of the demand. The first system used 290 m2 area of the roof and was sized as 40 kWp, the second used 109 m2 and was sized as 15.2 kWp. It was concluded that the reason for the low efficiency was the oversized design of the system. Incremental modernization efforts could help to improve the hydraulic system energy efficiency and make the design of the solar photovoltaic system realistically possible. Two types of PV systems where analyzed in the thesis work. A method was found calculating the load simulation sequence based on the energy efficiency studies to help in the PV system simulations. Hydraulic accumulators integrated into the pickling line worked as energy storage when being charged by the PV system as well.
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Mahmoud, Herman Abdulqadir Mahmoud. "Real-time operational response methodology for reducing failure impacts in water distribution systems." Thesis, University of Exeter, 2018. http://hdl.handle.net/10871/33492.
Повний текст джерелаАнотація:
Interruption to water services and low water pressure conditions are commonly observed problems in water distribution systems (WDSs). Of particular concern are the unplanned events, such as pipe bursts. The current regulation in the UK requires water utilities to provide reliable water service to consumers resulting in as little as possible interruptions and of as short possible duration. All this pushes water utilities toward developing and using smarter responses to these events, based on advanced tools and solutions. All with the aim to change network management style from reactive to a proactive, and reduce water losses, optimize energy use and provide better services for consumers. This thesis presents a novel methodology for efficient and effective operational, short time response to an unplanned failure event (such as pipe burst) in a WDS. The proposed automated, near real-time operational response methodology consists of isolating the failure event followed by the recovery of the affected system area by restoring the flows and pressures to normal conditions. The isolation is typically achieved by manipulating the relevant on/off valves that are located closely to the event location. The recovery involves selecting an optimal combination of suitable operational network interventions. These are selected from a number of possible options with the aim to reduce the negative impact of the failure over a pre-specified time horizon. The intervention options considered here include isolation valve manipulations, changing the pressure reducing valve’s (PRV) outlet pressure and installation and use of temporary overland bypasses from a nearby hydrant(s) in an adjacent, unaffected part of the network. The optimal mix of interventions is identified by using a multi-objective optimization approach driven by the minimization of the negative impact on the consumers and the minimization of the corresponding number of operational interventions (which acts as a surrogate for operational costs). The negative impact of a failure event was quantified here as a volume of water undelivered to consumers and was estimated by using a newly developed pressure-driven model (PDM) based hydraulic solver. The PDM based hydraulic solver was validated on a number of benchmark and real-life networks under different flow conditions. The results obtained clearly demonstrate its advantages when compared to a number of existing methods. The key advantages include the simplicity of its implementation and the ability to predict network pressures and flows in a consistently accurate, numerically stable and computationally efficient manner under both pressure-deficient and normal-flow conditions and in both steady-state and extended period simulations. The new real-time operational response methodology was applied to a real world water distribution network of D-Town. The results obtained demonstrate the effectiveness of the proposed methodology in identifying the Pareto optimal network type intervention strategies that could be ultimately presented to the control room operator for making a suitable decision in near real-time.
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Sjölund, Rickard, and Nicklas Vedin. "Steering System Modelling for Heavy Duty Vehicles." Thesis, Linköpings universitet, Reglerteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-119770.
Повний текст джерелаАнотація:
Future heavy duty vehicles will be designed and manufactured with improved Advanced Driver Assistance Systems, ADAS. When developing ADAS, an accurate model of the vehicle dynamics greatly simplifies the development process. One element integral to the vehicle lateral dynamics and development of ADAS is the steering system. This thesis aims to develop an accurate model of a heavy duty vehicle steering system suitable for simulations. The input to the system is an input torque at the steering wheel and the output is the wheel angle. Physical models of the system components are developed using bond graphs and known relations. Some components are modelled with non-linear inefficiencies and friction of different complexity. Unknown parameters and functions are identified from measurement data using system identification tools such as, for example, linear regression and non-linear grid search. The different subsystems are identified separately to the extent deemed possible. Different model designs are considered, validated, and compared. The advantages and disadvantages of different model choices are discussed. Finally, a non-linear state space model is selected for its high accuracy and efficiency. As this final model can be used to simulate a heavy duty vehicle steering system on a desktop computer faster than real time, it fulfills its purpose.
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Geiger, Chris, Niklas Maier, Florian Kalinke, and Marcus Geimer. "Assistance system for an automated log-quality and assortment estimation based on data-driven approaches using hydraulic signals of forestry machines." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71221.
Повний текст джерелаАнотація:
The correct classification of a logs assortment is crucial for the economic output within a fully mechanized timber harvest. This task is especially for unexperienced but also for professional machine operators mentally demanding. This paper presents a method towards an assistance system for machine operators for an automated log quality and assortment estimation. Therefore, machine vision methods for object detection are combined with machine learning approaches for estimating the logs weight based on a Convolutional Neural Network (CNN). Based on the dimensions oft he object ´log, a first categorisation into a specific assortment is done. By comparing the theoretical weight of a healthy log of such dimensions to the real weight estimated by the CNN-based crane scale, quality reducing properties such as beetle infestation or red rod can be detected. In such cases, the assistance system displays a visual warning to the operator to check the loaded log.
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Ukozehasi, Celestin. "A physiological basis to crop improvement and agronomic development." Thesis, University of Cambridge, 2015. https://www.repository.cam.ac.uk/handle/1810/248744.
Повний текст джерелаАнотація:
Despite of the documented impacts of the so-called green revolution, food security in the world faces new challenges in terms of population growth, increases in no-agricultural land use (urbanization), and climate change. Trends in food security show that the world community is operating within two limits of food system: (i) the quantity of food that can be produced under a given climate; and (ii) the quantity of food needed by a growing and changing population. Therefore, taking food security successfully into the future requires novel approaches to boost agricultural productivity in order to balance food supply and demand without expanding the agricultural land. To date, progress in wheat yield has been largely the result of the development of dwarf varieties through introgression of reduced height (Rht) genes. The height reductions arising from the presence of these genes increased yield by alteration of partitioning of dry matter and nitrogen in favour of the spike. However, increased partitioning through additional reductions in plant height is not likely; as comparative studies indicate that wheat yield is reduced when plants are shortened beyond a threshold, and most of the modern cultivars have reached the optimal height. Therefore, this dissertation aimed to identify the physiological attributes able to produce yield increases in the Rht genotypes with the optimal heights. Approaches based on physiological understanding of yield are necessary for developing genotypes combining high yielding potential and agronomic traits of superior adaptation, and for understanding yield limiting factors. Yet, direct measurement of physiological variables is often difficult or expensive; as an example, measuring plant water status in the field is problematic, with techniques such as psychrometry generally only being suitable for laboratory studies. Therefore, proxy such as tissue RWC may be a good alternative measure of plant water status. We aimed to address these questions with three components of experimental research :(i) proxy-based screening to increased photosynthetic rate and water use efficiency in wheat; (ii) determinants of increased HI in lines with different Rht genes (b, c) when incorporated into contrasting background wheat genomes (B, D), and the relative effect on N partitioning during grain filling; (iii) analyses of stable isotopes (δ²H, δ¹⁸O, δ¹⁵N and δ¹³C) in an agronomic perspective in alley cropping systems associated with adjacent N₂ fixing trees, in terms of hydraulic redistribution, N availability and crop yields. In this thesis, the proxy-based approach to crop selection was defined as a surrogate-based (proxy and surrogate used interchangeably) screening of cultivars for morphological, anatomical, and physiological traits of performance or crop environmental responses. The research proposed steps for conducting a proxy-based crop selection programme. A comparative screening of 23 Eps cultivars and ranking for traits of photosynthetic and water use efficiency showed the correlative relationships of SLA to An, WUEi, leaf N, Δ¹³C, Kh, leaf RWC, and IVD. Additionally, it was observed that IVD may influence WUE and Amax. It was suggested that these relationships of SLA to traits of photosynthesis possibly resulted from the association of SLA and the leaf biochemical characteristics. Attention was also given to examining the mechanistic foundations that determine the relationship between plant height and yield. The results showed the straw-shortening significantly correlated both with Amax and Kh; and SLA decreased with the level of dwarfing; and the Amax related both Kh and SLA. Therefore, it was proposed that the straw-shortening may affects Amax by exerting a controlling influence over Kh through SLA. Moreover, both the partitioning of N to spike and the flag leaf N were related to plant height and growth stage. Additionally, the increased post-anthesis partitioning of N to grain associated with high N uptake rate and high MRT of N were probably the traits behind increased NUE and NHI. The data also indicated that increased grain number per spike, kernel weight and reduced peduncle length might be the driver of the increased HI in this experiment. The test of the hypothesis that there might be practical application of the analyses of the natural abundance of stable isotopes (δ²H, δ¹⁸O, δ¹³C, and δ¹⁵N) and isotopic mixing model by IsoSource to understand plant interactions in terms of water redistribution and nitrogen transfer and uptake in agroforestry systems, indicated a consistent gradient in depletion of wheat xylem water δ²H, δ¹⁸O, and δ¹⁵N in leaf as moving further away from the tree line. The data also reflected a consistent pattern of isotopic values (δ²H, δ¹⁸O, and δ¹⁵N) in wheat in the proximity of the tree being similar to that of the tree, suggesting they were using the same source of water and N. Similarly, an isotopic mixing model data showed that the crops in the proximity of the trees accessed considerably amounts of the water and nitrogen redistributed by trees. The study also indicated the improvement in water use efficiency, chlorophyll content, grain number per spike, and grain yield for the crops nearest to the trees for a distance up to 5 m. In conclusion, selection for increased HI should shift focus from reduced plant height to include increased grain number and kernel weight, increased partitioning of N to spike, reduced peduncle length, and low SLA. Finally, the hypothesis that efflux of water and N in agroforestry system from tree roots in topsoil and influences a number of physiological functions of neighbouring crops was confirmed by isotopic and physiological data.
27
Skvorchevsky, Alexander Evgenievich. "Modern requirements for electrohydraulic drives of combat and civilian vehicles." Thesis, Національний технічний університет України "Київський політехнічний інститут"; Механіко-машинобудівний інститут, 2016. http://repository.kpi.kharkov.ua/handle/KhPI-Press/28264.
Повний текст джерела
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Seung, Taehun. "Holistic-Lightweight Approach for actuation systems of the next generation aircraft." Universitätsverlag Chemnitz, 2017. https://monarch.qucosa.de/id/qucosa%3A34400.
Повний текст джерелаАнотація:
Currently the system development of aircraft engineering concentrates its focus on the reduction of energy consumption more than ever before. As a consequence, the efficiency of subsystems inside the aircraft is highlighted. According to previous investigations the simplification/unification of conventional multifaceted board energy systems by means of electric power management is the most promising way concerning aircraft global efficiency improvement.
The main aim of the present work was to optimize a multi-device, heavy duty EHA-System by introducing of a comprehensive perspective. In order to achieve the final, non-plus-ultra improvement level, the attributes of architecture, hardware and operation method were combined in an interactive manner, whereas particular attention has been paid to the mutual enhancing influences.
The maximum reduction of losses, the minimizing of consumption and weight optimization can be achieved concurrently when the physical coherences between the involved subsystems are understood and their hidden potentials are exploited.
This can only be achieved in one way and the detail follows: The most effective way to reduce both manufacturing effort and weight is to introduce a multiple-allocation philosophy. The highest reliability possible can be achieved by novel cascade-nested system architecture and strict restraining of the control logic. By employing an ultra-low-loss hardware concept, the energy efficiency can be maximized at a necessary minimum own weight. Last but not least, possibly the most important cognition is that an intelligent operation method will improve the actual system and influence the entire system positively and with a lower effort.
The final conclusion is that the only and reasonable way to achieve an ultimate optimized solution of an actuation system is an all-encompassing consideration. Eventually it was to recognize that the final result is nothing but ultimate lightweight architecture, i.e. a non-plus-ultra solution.Gegenwärtig konzentriert sich die Technologieentwicklung für Flugzeuge auf die Reduktion des Energieverbrauchs mehr denn je zuvor. Hierfür ist die Effizienz der an Bord befindlichen, nicht propulsiven Subsysteme neben der Wirkungsgradverbesserung der Triebwerke von zentraler Bedeutung. Laut vorangegangenen Untersuchungen und Studien ist die Vereinfachung bzw. Vereinheitlichung der Vielfalt der konventionellen Bordenergiesysteme durch ein adäquates Energiemanagement unter Verwendung von Elektrizität der aussichtsreichte Weg zur Effizienzverbesserung auf der Gesamtflugzeugebene. Durch die Elektrifizierung wurden die einzelnen Geräte zwar zuverlässiger und energieeffizienter als je zuvor aber gleichzeitig erheblich schwerer, sodaß ein signifikanter Verlust an Nutzlasten auf Gesamtflugzeugebene hervorgerufen wird. Das Hauptziel der vorliegenden Arbeit war es, ein Schwerlast-EHA-System mit mehrfachen Betätigungseinheiten durch Einführung von umfassenden Perspektiven zu optimieren. Durch Einführung der sog. ganzheitlichen Leichtbauweise demonstriert die Arbeit, wie das Subsystem mit mehreren Endgeräten ultimativ optimiert werden kann, ohne Abstriche an Gewichtsbilanz u/o Kompromiß mit der Energieeffizienz zu machen. Um eine wahrhaftige Optimierung, d.h. die Erreichung des ultimativen, Nonplusultra-Verbesserungslevels zu erreichen, wurden die Systemarchitektur, die Hardware und die Operationsmethode interaktiv kombiniert, wobei die besondere Aufmerksamkeit auf die interaktiven, zur Verbesserung führenden Einflüsse gelegt wurde. Die Minimierung des Energieverbrauchs und die ultimative Gewichtsoptimierung gleichzeitig können erreicht werden, wenn die physikalischen Zusammenhänge zwischen den involvierten Subsystemen verstanden und ihre verborgenen Potentiale ausgenutzt werden. Der einzige und vernünftige Weg zur Erreichung der ultimativen Optimierung eines Betätigungssystems ist eine allumfassende Betrachtung, also eine ganzheitliche Betrachtungs- bzw. Vorgehensweise.
29
Heyns, Louis Jacobus. "Describing function-based control synthesis for a nonlinear hydraulic drive system." Thesis, 2014. http://hdl.handle.net/10210/9688.
Повний текст джерелаАнотація:
M.Ing.Experimental tests have indicated that limit cycles are likely to occur in hydraulic drive systems, where backlash in the actuator seals is the dominant nonlinearity'. This study primarily deals with the analysis and synthesis of existing hydraulic drive systems to eliminate limit cycles and with establishing a design tool for the design of hydraulic drives with the object of avoiding limit cycles. Most analytical results were verified experimentally. The most general methods for the design of practical nonlinear systems are discussed. It is concluded that some form of synthesis and analysis is necessary, and that the need exists for general methods to evaluate the stability of nonlinear systems and design tools for nonlinear system design. Ageneral procedure of system analysis is given. Amathematical model of the system needs to be obtained, which can be done with the aid of bond graphs. Simulations of complex systems are recommended to verify system performance only. The first procedure of system analysis that should be followed is to systematically identify elements of the system which are not related to the cause of the limit cycle. Experimental testing is a good first step in identifying the non-critical elements. Signal flow diagrams enable the engineer quickly to determine all feedback loops of a complicated system which might be critical. Block diagrams are necessary for the application of nonlinear analysis and synthesis techniques. Hydraulic resonance, where the actuator seal acts as an oscillating mechanism, is identified as a possible cause of the limit cycle. An unusual application of the describing function, where the describing function is applied to optimize the hydraulic supply, is discussed. The transfer function of flow in a hydraulic pipe is given. With the use of the describing function, the gain margin can be studied versus different parameters of the plant. This gives insight into slightly damped conditions of the hydraulic supply that might be the cause of a limit cycle in the system. A control gain does not change the dynamic behaviour of the hydraulic supply, but only amplifies certain natural modes of the system. The design application of the describing function to nonlinear hydraulic drives is discussed. Procedures to eliminate an existing limit cycle and to design a nonlinear hydraulic drive system are proposed. Most important of all, is to design the system so that the natural frequencies of the mechanical structure and the hydraulic supply do not have any common multiples.
30
余均哲. "Design of a Compressed Air Driven Hydraulic Motor System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/09022515772408888551.
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鄭傑. "Electric Controller Design of a Compressed Air Driven Hydraulic Motor System and and Bird-type Hydraulic Motor System Design." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/50792360001317087149.
Повний текст джерела
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Chih, Dai Shang, and 戴尚智. "Design and Improvement of a Compressed Air Driven Motor Hydraulic System." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/98213756237190519578.
Повний текст джерелаАнотація:
碩士國立清華大學
動力機械工程學系
104
The purpose of this research is to redesign the compressed air driven hydraulic motor system which is designed in the former research and to improve the control method and system efficiency. In this research, intake pipe system is rearranged. A new mode of operation to recover residual pressure is used. This recovering mode can boost the system to improve the system efficiency. Finally, we measure system efficiency in expand mode and isobaric mode to find out the optimum operating parameters.
33
Yang, Ting Yuan, and 楊霆遠. "Oil Line Design and Control Method of a Compressed Air Driven Hydraulic Motor System." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/89161893279976001313.
Повний текст джерелаАнотація:
碩士國立清華大學
動力機械工程學系
103
The purpose of this research is to redesign the compressed air driven hydraulic motor system which is designed in the former research and improve the oil line and control method. In this research, the valves in the piping system are rearranged to reduce the energy loss. The influence of the accumulators is also discussed. The use of the flow control valve and pneumatic ball valve controls the flow into the accumulator and adjusts the preload of accumulator to achieve better efficiency. To improve the control method, the system is added a new control phase and the control code are designed to decrease the consumption of power. Besides, the difference between the new piping system and old piping system is compared and measure the efficiency of high pressure/low pressure、constant pressure/expansion operations.
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Nunes, Pedro Daniel da Cunha Moreira. "Analysis of the use of variable speed drives in water supply systems." Master's thesis, 2021. http://hdl.handle.net/10773/31361.
Повний текст джерелаАнотація:
Currently, operational control at the pumping stations is based on the water
levels present in the tanks, ie, each time the water level reaches a certain
minimum value, the pumps switch on until the tank is full again. Although
this type of control is quite effective, it is also quite inefficient. This type
of operation can be largely optimized by adjusting pumping operations to
energy prices that vary throughout the day. Additionally, the use of variable speed drives can also increase the efficiency of the pumps due to its
adaptations to daily water consumption. However, this type of operation
imposes several challenges such as (i) the high difficulty of the operator to
accurately predict water consumption patterns every day and for all types
of consumers by intuition ; (ii) associate water needs with fluctuations in
energy tariffs and with low storage capacity of reservoirs; (iii) know the ideal
frequency to pump the water with the lowest energy consumption and (iv)
know the equipment used, which, over time, its efficiency decreases substantially. With complex and large systems (such as water supply systems), the
attempt to improve operational efficiency can be a "shot in the dark", which
can lead to serious implications on the minimum requirements required by
final consumers (such as pressures or security of supply). In this thematic
area, the goal of this work is to contribute to an increase in the efficiency of
these systems. Different studies results are described in the literature, studies concerning the application of VSDs. However, even though they show
good results when it comes to energy savings, there is still doubt among the
community on the advantages of applying the VSDs, and above all there
is still a lack of information on how to use the VSDs. The main goal of
this study is to present the benefits of using VSDs, as well as explaining its
application. Python simulations were developed with different scenarios for
a water distribution network, using VSDs and pumps, even at parallel use.
The results achieved were satisfactory and present values of energy savings
within expectations.Atualmente, o controlo operacional nas estações elevatórias de àgua é feito com base nos níveis de àgua presentes nos reservatório, ou seja, cada vez que o nível da àgua atinge um determinado valor mínimo, as bombas são ligadas até o reservatório ficar cheio novamente. Embora este tipo de controlo seja bastante eficaz, também é bastante ineficiente. Este tipo de operação pode ser amplamente otimizado ajustando as operações de bombeamento aos preços de energia que variam ao longo do dia. Além disso, a utilização de variadores de velocidade também pode aumentar a eficiência das bombas devido às suas adaptações ao consumo diário de àgua. No entanto, este tipo de operação impõe vários desafios, como (i) a grande dificuldade do operador em prever com precisão os padrões de consumo de àgua todos os dias e para todos os tipos de consumidores por intuição; (ii) associar as necessidades de água às flutuações das tarifas de energia e à baixa capacidade de armazenamento dos reservatórios; (iii) saber a frequência ideal para bombear a água com menor consumo de energia e (iv) conhecer os equipamentos utilizados, que, com o tempo, a sua eficiência diminui substancialmente. Com sistemas complexos e grandes (como sistemas de abastecimento de àgua), a tentativa de melhorar a eficiência operacional pode ser um "tiro no escuro", o que pode levar a sérias implicações nos requisitos mínimos exigidos pelos consumidores finais (como pressão ou segurança no fornecimento). Nesta área temática, o objetivo deste trabalho é contribuir para o aumento da eficiência destes sistemas. Resultados de diversos estudos são descritos na literatura, estudos relativos à aplicação de VSDs. Porém, embora apresentem bons resultados no que se refere à economia de energia, ainda há dúvidas na comunidade sobre as vantagens da aplicação dos VSDs e, sobretudo, ainda falta informação sobre como utilizar os VSDs. O objetivo principal deste estudo é então apresentar os benefícios da utilização de VSDs, bem como explicar a sua aplicação. Simulações em Python foram desenvolvidas com diferentes cenários para uma rede de distribuição de água, usando VSDs e bombas hidráulicas, até com utilização em paralelo. Os resultados alcançados foram satisfatórios e apresentam valores de poupança de energia dentro das expectativas
Mestrado em Engenharia Mecânica
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Chikh, Al Souk M. Molham Hasan. "Optimum design and control of hydraulic systems driven by swash plate pumps using vibration based diagnosis." Thesis, 2008. http://spectrum.library.concordia.ca/976026/1/NR42550.pdf.
Повний текст джерелаАнотація:
Swash plate pumps are widely used to drive hydraulic systems, especially because they offer high specific power. In order to improve their performance and make them more reliable, it is necessary to reduce the flow fluctuations, incorporate a control system that is more responsive, and minimize vibration levels. Furthermore, the flow should be controlled according to load requirements and pipe response at the design level. Moreover, there is a need to monitor the health of the system by analysing its vibration signatures. A novel port plate design is used with a pair of deep silencing grooves on the edges of delivery and suction ports, which reduces the flow fluctuations and improves the pump output. In addition to the load information, the pipe dynamics are also used as a control input. Hence, pipe instabilities with different boundary conditions are studied, where simple, accurate and comprehensive expressions to describe the pipe instabilities are produced, solved, and plotted. In swash plate pumps, the control unit changes the pump output according to the load requirements. The current pump design is equipped with a double negative feedback strategy. The inner loop controls the spool position, and the outer loop controls the swash plate angle. Since this design has a high rise time, it was suggested to equip the pump with a single feedback PD controller. Although this reduced the rise time, it introduced high levels of vibration. The present research proposes a new control strategy with a single feedback PID controller that minimizes vibration levels. Results are obtained experimentally. The control strategy is generalized to control the pump flow according to load requirements and pipe vibration levels. A compensation factor is introduced to moderate the negative impact of the pipe vibrations, and to generate a new set value for the inclination angle. For timely detection of faults, the application of wavelet analysis to detect different defects is examined. Some defects are produced, such as pipe flutter, pump dynamic instability, and voltage unbalance in the driving electric motor. Continuous wavelet and discrete wavelet analyses are used to analyze the vibration signature by using Debauches' mother wavelet. The data is collected experimentally. The results show that wavelet analysis is very efficient at identifying defects in the pipe or pump. The results are discussed and appropriate conclusions are drawn based on the present research. Suggestions for future extensions of the research are proposed
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(9712886), Michael Roggenburg. "TECHNO-ECONOMICS ON THE APPLICATION OF HYDRAULICS IN WIND TURBINE DRIVE-TRAINS & THE DEVELOPMENT OF INTEGRATED RENEWABLE ENERGY SYSTEMS FOR USE IN WATER SECURITY ALONG THE US-MEXICO BORDER." Thesis, 2020.
Знайти повний текст джерелаАнотація:
Renewable energy adoption is critical when considering future energy grids and how they impact the environment, economy and society. While fossil fuels have traditionally been employed to generate the electricity used across every facet of the global economy, renewables are becoming increasingly more attractive as a substitute. Fossil fuels have historically outperformed their clean energy counterparts in terms of levelized cost. However, over the last few decades renewables have become extremely cost competitive and are starting to outpace their opposition as advancements in technology continue. As the cost gap between “brown” and “green” energy sources decreases, energy grid mixes will adopt more sustainably responsible generation, positively impacting the planet.
In the following thesis, two studies are presented which demonstrate new innovations for decreasing the cost of offshore wind energy and how renewables and desalination can be integrated along the US-Mexico border. The first study describes an itemized breakdown of how substituting the mechanical transmission with hydraulics can lower the life-time cost of an offshore wind turbine. The second analysis details a complex wind and solar powered clean water production and distribution network to combat ongoing water scarcity along the US-Mexico border. Both concepts push the boundaries of scientific innovation and its application for solving social and economic issues.
37
Ammanagi, Soumayya. "Vibration Testing of Structures under Random Support Excitations." Thesis, 2015. http://etd.iisc.ernet.in/2005/3912.
Повний текст джерелаАнотація:
Vibration testing of structures constitutes a crucial step in design and commissioning of engineering structures. The focus here is on simulating field conditions in a laboratory so that detailed investigations of the structural behavior under various future load scenarios can be carried out. A major enabling technology in recent years in this field of study, especially, in the context of earthquake engineering, and automotive testing, has been the development of servo-hydraulic actuation systems, which form the principal component of test facilities, such as, multi-axes shake tables for testing building structures under earthquake loads, multi-post testrigs for testing vehicles subjected to road loads, and reaction-wall based test systems for simulating horizontal effects of earthquake loads on building structures. These systems have enabled the conduct of systematic studies on simulation of nonlinear structures under transient loads, simulation of multi-component and spatially varying random loads, and combining numerical and experimental methods with a view to avoid scaling while testing small scale critical components of large built-up structures. The investigations reported in this thesis are in this area of research and are primarily aimed at exploring the potential of servo-hydraulic test systems to address a few intricate issues related to performance assessment of engineering vibrating systems.
A broad-based overview of goals of experimental approaches in vibration engineering, including dynamic system characterization and performance assessment, is presented in Chapter 1. Also discussed are the brief details of vibration testing methods developed in the context of earthquake engineering (including quasi-static test, effective force test, shake table test, combined effective force and shake table test, various versions of pseudo-dynamic test, and real-time substructuring) and automotive vehicle testing (including input excitation based methods and response based methods). The discussion notes the remarkable success witnessed in combining mathematical methods and experimental techniques especially in problems of characterization of dynamic system properties. Similar success, however, is observed to be not wide-spread in the context of development of test methods aimed at performance assessment of vibrating systems. The review culminates with the identification of the following three problems to be tackled in the present thesis: (a) development of efficient experimental procedures to estimate time varying reliability of structures under multi-component earthquake loads and similar analysis of vehicle structures under spatially varying random road loads; the focus here is on achieving sampling variance reduction in estimating the reliability; (b) development of experimental procedures to determine optimal cross-power spectral density models of partially specified multi-component random loads so as to produce the highest and lowest response variance in a specified response variable; the focus here is on seismic tests of asymmetric structures under partially specified multi-component earthquake loads, and on characterizing optimal correlations between two parallel tracks which maximize or minimize the vehicle response; and (c) development of a modified pseudo-dynamic test procedure, to incorporate additional components in numerical and experimental modeling in terms of an augmented linearized variational equation, so as to assess and contain propagation of numerical and experimental errors. The subsequent three chapters of the thesis tackle these questions and in doing so the thesis makes the following contributions:
(A) Inspired by the Girsanov transformation based Monte Carlo simulation method for estimating time-variant component reliability of vibrating systems, an experimental test procedure, which incorporates the Girsanov transformation step into its folds, has been developed to estimate the time-variant system reliability of engineering systems. The two main ingredients of application of this strategy consists of determination of a control vector, which is artificially introduced to facilitate reduction in sampling variance, and the formulation of the Radon-Nikodym derivative, which serves as the correction to be introduced in order to compensate for the addition of the artificial control. (B) In problems of response analysis of structures subjected to random earthquake loads and vibration of vehicles running on rough roads, it may not be always feasible to completely specify the external actions on the structures. In such situations, it is of interest to determine the most favorable and the least favorable responses, along with the models for missing information in the inputs which produce the extreme responses. The present study, again inspired by existing analytical solutions to this problem, develops an experimental procedure to characterize the optimal excitation models and associated responses. (C) In the context of PsD testing of nonlinear structure to earthquake loads, a refinement in the test procedure involving the treatment of a linearized variational equation is proposed. This has led to the estimation of the evolution of global error norm as test proceeds with time. The estimates of error thus obtained have been used to decide upon altering the time step of integration.