Academic literature on the topic 'Pneumatic unit dynamics'
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Journal articles on the topic "Pneumatic unit dynamics"
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Stoll, Johannes T., Kevin Schanz, and Andreas Pott. "Mechatronic Control System for a Compliant and Precise Pneumatic Rotary Drive Unit." Actuators 9, no. 1 (December 20, 2019): 1. http://dx.doi.org/10.3390/act9010001.
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Robots that enable safe human-robot collaboration can be realized by using compliant drive units. In previous works, different mechanical designs of compliant pneumatic rotary drive units with similar characteristics have been presented. In this paper, we present the overall control approach that we use to operate one of these compliant pneumatic rotary drive units. We explain the mechanical design and derive the differential equation that describes the dynamics of the system. In order to successfully operate a pneumatic drive unit with three or more working chambers, the torque specified by the controller has to be split up onto the working chambers. We transfer the well-known field-oriented control approach from electric motors to the investigated pneumatic drive unit to create such a torque mapping. Moreover, we develop optimized torque mappings that are tailored to work with this type of drive unit. Furthermore, we introduce and compare two control algorithms based on different implementations of state feedback to realize position control. Finally, we present the step responses that we achieve when we implement either one of the control algorithms in combination with the different torque mappings.
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Carmona, M., S. Marco, J. Samitier, M. C. Acero, J. A. Plaza, and J. Esteve. "Modeling the Thermal Actuation in a Thermo-Pneumatic Micropump." Journal of Electronic Packaging 125, no. 4 (December 1, 2003): 527–30. http://dx.doi.org/10.1115/1.1604154.
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The analysis of a thermo-pneumatic actuation unit for its use in a micropump has been carried out. Coupled thermo-mechanical simulations by finite element method (FEM) (with ANSYS software) were required because of the complexity of the device. The simulation results were validated by thermal and mechanical experimental results, showing a good agreement. FEM results have been used to extract a high level model of the actuation unit that can be used to estimate the maximum performance of the micropump operation with this actuation unit. In order to identify the best frequency of operation for the pump, a quality parameter has been defined based on the thermal dynamics of the actuation unit.
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Leontiev, Aleksandr, Vitalii Tauger, Evgenii Volkov, and Volkov Volkov. "The dynamics of a laden skip of the shaft pneumatic winding plant during acceleration." Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal, no. 1 (February 17, 2021): 115–21. http://dx.doi.org/10.21440/0536-1028-2021-1-115-121.
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Introduction. Ratios for calculating the laden skip acceleration and speed at the motion start are required to calculate skip pneumatic winding plant cycle components. The ratios are the solution to the skip dynamics equation which takes into account the relationship between the flow generated by a power unit and air pressure. Research methodology. The dynamics equation including the dependence of the pressure on the flow rate (aerodynamic characteristic) in a general form is compiled. In a special case of the unit’s physical model, a discharge unit with a linear aerodynamic characteristic is used. Research result. For a particular case, equations are obtained that allow to theoretically describe the kinematic parameters of a skip in the period of unsteady motion. It is established that the skip acceleration, velocity and displacement are asymptotic functions. The obtained expressions for kinematic parameters make it possible to theoretically determine the duration of the acceleration period and the path that the ISSN 0536-1028 «Известия вузов. Горный журнал», № 1, 2021 121 skip takes during this period. A method for calculating skip dynamics during acceleration is proposed, which contains approximating formula conclusion for the power unit aerodynamic characteristics, its substitution into the dynamics equation, and obtaining skip kinematic parameters by solving the dynamics equation. Conclusion. The obtained relations allow to calculate skip dynamics during acceleration taking into account power unit aerodynamic characteristics, which is necessary to determine the working cycle time of the pneumatic winding plant.
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Bobrow, J. E., and F. Jabbari. "Adaptive Pneumatic Force Actuation and Position Control." Journal of Dynamic Systems, Measurement, and Control 113, no. 2 (June 1, 1991): 267–72. http://dx.doi.org/10.1115/1.2896374.
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In this paper an implementation of an adaptive control law for a pneumatic actuator is presented. Pneumatic actuators are of particular interest for robotic applications because of their large force output per unit weight, and their low cost. Stabilization of a pneumatic actuator is difficult if a high bandwidth closed-loop system is desired. This is because of the compressibility of air, and of the nonlinear characteristics of air flowing through a variable area orifice. Further complications arise from the geometry of the mechanism because the equations of motion are highly nonlinear. The order of the dominant dynamics is shown to vary with the position of the mechanicsm.
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Efremova, K. D., and V. N. Pilgunov. "Pneumatic Muscle: Geometry of the Cylindrical Membrane and The Power Characteristic Prognostic." Mechanical Engineering and Computer Science, no. 3 (April 8, 2018): 20–34. http://dx.doi.org/10.24108/0318.0001377.
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The pneumatic muscle is a pneumatic motor of the single-acting reciprocating motion. It is designed to create apullingforce. Return of the pneumatic muscle to its original position is provided by elastic deformation of its shell. A cylindrical membrane with the hard bottom and the lid provides the basis of the pneumatic muscle.The membrane cord is formed in the process of helically shaped CU-braid of the threads made from the super-hard synthetic fibres (for example, Kevlar). After the cord is filled with an elastomer, a strong, deformable and elastic shell is formed. An excessive pressure applied to the internal cavity of the membrane arises an extension of the tangent diagonal and a simultaneous shortening of the axial diagonal in the diamond-shaped cell, which is formed as a result of braid of cord threads. This results in pneumatic muscle’s retraction up to 25% of its original length, while creating a sufficiently large contraction force, which depends significantly on the contraction value.Using the cord structure of the MAS series pneumatic muscles of the company “FESTO” as an example, we have investigated a diamond-shaped cell deformation of the membrane and have defined a numerical dependence of its internal diameter and the volume of the internal cavity of the pneumatic muscle on the contraction value. This allowed us to develop a mathematical model of an idealized cylindrical membrane whose dynamics does not take into account a deformation force of the elastomer, filling a diamond-shaped cell.The experimental studies of industrial samples of the MAS 10 family of pneumatic muscles, carried out using a specially designed unit, allowed us to obtain their force characteristics. In the numerical representation, these characteristics turned out to be 2.5 ... 3 times less than the force characteristics of the pneumatic muscle with an idealized membrane, thereby allowing us to draw conclusions that the elastomer deformation forces have a significant influence. There is a proposal to take into account the elastomer deformation effect on the force characteristics of the pneumatic muscle by dint of the correction factor available from a comparative estimate of the force characteristics of the idealized membrane and the normalized force characteristics of the pneumatic muscles of the MAS family.The results of the performed studies allow us to predict the force characteristics of pneumatic muscles at the stage of their design and in-service.
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Godzhaev, Z. A., and A. M. Pogozhina. "Prospects for the development of undercarriage systems of modern mobile energy devices for agricultural purposes." Traktory i sel hozmashiny 85, no. 5 (October 15, 2018): 76–84. http://dx.doi.org/10.17816/0321-4443-66429.
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The final stage of the cultivation of crops is harvesting. The quality of the operation depends on the annual result of the effectiveness of all previous work. It is important not only to harvest well, but to preserve the fertility of the soil and avoid soil compaction. The problem of compression is becoming more acute due to the massive use of heavy wheeled tractors and combines. The degree of soil compaction depends on the type of propulsion unit, the weight of the tractor and the number of passes of the units across the field. The negative impact of undercarriage systems on the soil should be considered when creating new machines based on new layout schemes, to reduce the structural weight, taking into account the dynamics and distribution of the center of mass of the variation in hook load. To reduce pressure and evenly distribute it is possible through the creation of more advanced propulsion and suspension systems. The purpose of this article is to analyze the most promising designs of the mobile agricultural machinery undercarriage systems, which can reduce the specific pressure on the ground, improve the throughput of agricultural machinery and provide a more comfortable planting and harvesting. At the moment, the following main directions of development of agricultural machinery undercarriage systems can be distinguished: pneumatic tracks, twin wheels, half-track, installation of rubber-reinforced tracks (RRT) and torsion as an elastic suspension element. The tests carried out confirmed that the installation of a changeable tracked propulsion unit can reduce the degree of soil compaction by 17-46 %, and the use of twin wheels showed an increase in pulling force by 20 % and a decrease in gauge depth by 40 %. The use of pneumatic trackers allows to increase the permeability of the transport vehicle on soils with a weak bearing capacity and at the same time minimize the damage that it can cause to the supporting base. Recently it is popular to operate the agricultural machinery, which uses rubber-reinforced caterpillar. Its caterpillar operational cycle if higher of 4-5 times comparing to those from metal. In addition, it allows to reduce vibration load and do the work at wet soil conditions. RRT is put both in the all-track version, and in the form of a wheel-caterpillar. This propulsion unit has a triangular shape of rubber tracks is mounted instead of wheels. Currently, individual torsion hangers of track rollers are widely used on tracked tractors. The advantages of the new torsion-balance suspension made it possible to increase the reliability and durability of tracked tractors undercarriage systems.
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Zhang, Yu, Wenchuan Zhao, Ning Wang, and Dengyu Lu. "Development and Performance Analysis of Pneumatic Soft-Bodied Bionic Basic Execution Unit." Journal of Robotics 2020 (November 3, 2020): 1–13. http://dx.doi.org/10.1155/2020/8860550.
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This paper studies the design of pneumatic soft-bodied bionic basic execution unit with soft-rigid combination, which can be used as an actuator for pneumatic soft-bodied robots and soft-bodied manipulators. This study is inspired by structural characteristics and motion mechanism of biological muscles, combined with the nonlinear hyperelasticity of silica gel and the insertion of thin leaf spring structure in the nonretractable layer. Response surface analysis and numerical simulation algorithm are used to determine the optimal combination of structural dimension parameters by taking the maximum output bending angle of the basic executing unit as the optimization objective. Based on Odgen’s third-order constitutive model, the deformation analysis model of the basic execution unit is established. The physical model of pneumatic soft-bodied bionic basic execution unit is prepared through 3D printing, shape deposition, soft lithography, and other processing methods. Finally, the motion and dynamic characteristics of the physical model are tested through experiments and result analysis, thus obtaining curves and empirical formulas describing the motion and dynamic characteristics of the basic execution unit. The relevant errors are compared with the deformation analysis model of the execution unit to verify the feasibility and effectiveness of the design of the pneumatic soft-bodied bionic basic execution unit. The above research methods, research process, and results can provide a reference for the research and implementation of pneumatic and hydraulic driven soft-bodied robots and grasping actuators of soft-bodied manipulators.
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Kuz´niewski, B. "Nonlinearity and Feedback Compensation Method in a Pneumatic Vibration Generator." Journal of Dynamic Systems, Measurement, and Control 122, no. 1 (March 8, 1996): 163–67. http://dx.doi.org/10.1115/1.482437.
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The paper presents a model of a pneumatic piston unit and analyzes dynamic processes taking place in the unit generating periodic signals. Nonlinearities and feedback occurring in flow and vibration processes are determined. A method of nonlinearity and feedback compensation by input parameters of air streams is presented. [S0022-0434(00)00201-X]
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VERRELST, BJÖRN, JIMMY VERMEULEN, BRAM VANDERBORGHT, RONALD VAN HAM, JORIS NAUDET, DIRK LEFEBER, FRANK DAERDEN, and MICHAEL VAN DAMME. "MOTION GENERATION AND CONTROL FOR THE PNEUMATIC BIPED "LUCY"." International Journal of Humanoid Robotics 03, no. 01 (March 2006): 67–103. http://dx.doi.org/10.1142/s0219843606000655.
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This paper reports on the control structure of the pneumatic biped "Lucy." The robot is actuated with pleated pneumatic artificial muscles which have interesting characteristics that can be exploited for legged machines. They have a high power-to-weight ratio, an adaptable compliance and they can reduce impact effects. The current control architecture focuses on the trajectory generator and the tracking controller, which is divided into a computed torque controller, a delta-p unit, a PI position controller and a pressure bang-bang controller. The trajectory generator provides polynomial joint trajectories while the computed torque, combined with the delta-p unit, calculates the required muscle pressure levels. The PI and bang-bang controller work at a pressure level to cope with modeling errors and to set the pressures in each muscle. The control design is divided into single support and double support, where specifically the computed torque differs for these two phases. The proposed control architecture is evaluated with a full hybrid dynamic simulation model of the biped. This simulator combines the dynamical behavior of the robot with the thermodynamical effects that take place in the muscle-valves system. The observed hardware limitations of the real robot and expected model errors are taken into account in order to give a realistic qualitative evaluation of the control performance and to test the robustness. A preliminary implementation of the presented controller on the real biped, representing a walking motion of the robot while both feet are in the air, is discussed. This first implementation shows already promising results concerning tracking performance of the proposed control architecture. It confirms that the pneumatic tracking system can be used for a dynamic application such as a biped walking robot.
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Kushnir, V. G., O. A. Benyukh, I. N. Shilo, N. N. Romanyuk, and V. A. Ageychik. "Improvement of suspension system of mobile power units." Traktory i sel hozmashiny 81, no. 5 (May 15, 2014): 37–39. http://dx.doi.org/10.17816/0321-4443-65620.
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Original designs of pneumatic-tyre movers and vehicle suspension are proposed. Their use will permit to increase reliability, operation durability, ride comfort, and cross-country capability of machine and tractor unit; to improve operator work conditions; to decrease vertical vibration and dynamic loads on supporting surface as well as soil compaction.
Dissertations / Theses on the topic "Pneumatic unit dynamics"
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Шевченко, Сергій Андрійович. "Удосконалення пневмосистеми запуску ракетних двигунів шляхом стабілізації тиску робочого тіла та поліпшення її динамічних характеристик." Thesis, НТУ "ХПІ", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/29030.
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Дисертація на здобуття наукового ступеня кандидата технічних наук зі спеціальності 05.05.17 – гідравлічні машини та гідропневмоагрегати. – Національний технічний університет "Харківський політехнічний інститут". – Харків, 2017.
Дисертація присвячена дослідженню вдосконаленої пневмосистеми багаторазового запуску маршового рідинного ракетного двигуна верхнього ступеня ракети-носія. Система запуску, яка містить частину пневмоблока двигуна, здійснює розкручування турбонасосного агрегату за рахунок подачі стисненого гелію на його турбіну. Особливістю системи є використання регулятора тиску гелію із пневмокеруванням. Розроблений й реалізований у практиці проектування новий комплекс дискретно-континуальних математичних моделей для газодинамічного розрахунку цієї пневмосистеми, а також аналізу сил тертя й витоків газу у фторопластових манжетних ущільненнях регуляторів. Запропоновано новий розрахунковий метод дослідження пневмосистеми, що проектується, на динамічну стійкість. Досліджені газодинамічні характеристики металлорукава. Розроблено нову концепцію й впроваджено конструкцію лабораторного стенда, що дозволяє економити гелій при доводочних випробуваннях системи. Виконано розрахунково-експериментальне дослідження пневмосистеми, а його рекомендації зі зміни параметрів регулятора, що знижують коливальність і поліпшують інші динамічні характеристики, впроваджені на двигуні.The thesis for the scientific degree of the Candidate of Technical Sciences by specialty 05.05.17 – hydraulic machines and hydropneumatic units. – National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2017. The dissertation describes research of perfected pneumatic starting system of a main restartable liquid-propellant rocket engine destined for a launch vehicle upper stage. The starting system, which structure includes a part of the engine pneumatic unit, performs turbopump spin-up by supplying compressed helium to its turbine. A feature of the system is application of a pneumatically controlled helium pressure regulator. New complex of discrete-continual mathematical models is developed and implemented in the designing practice for the gas-dynamic analysis of this pneumatic system and analysis of friction forces and gas leaks through fluoroplastic lip-type seals of regulators. New computational method is proposed for the developed system’s dynamic stability research. The gas-dynamic characteristics of a metal hose are researched. New concept of the laboratory stand is developed and implemented to enable helium saving at development tests. Experimental-computational research of the pneumatic system is performed, recommendations of which are introduced into the engine in relation to the regulator parameters reducing oscillations and improving other dynamic characteristics.
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Шевченко, Сергей Андреевич. "Усовершенствование пневмосистемы запуска ракетных двигателей путём стабилизации давления рабочего тела и улучшения её динамических характеристик." Thesis, Государственное предприятие "Конструкторское бюро "Южное" им. М. К. Янгеля", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/29036.
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Диссертация на соискание ученой степени кандидата технических наук по специальности 05.05.17 – гидравлические машины и гидропневмоагрегаты. – Национальный технический университет "Харьковский политехнический институт". – Харьков, 2017.
Диссертация посвящена исследованию усовершенствованной пневмосистемы многократного запуска маршевого жидкостного ракетного двигателя верхней ступени ракеты-носителя с насосной подачей компонентов топлива в камеру сгорания. Система запуска, в состав которой входит часть пневмоблока двигателя, осуществляет раскрутку турбонасосного агрегата за счет подачи сжатого гелия из шаробаллона на турбину. Особенностью системы является использование регулятора давления гелия с пневмоуправлением. Исследованная система обеспечивает пять включений двигателя РД861К при идентичных импульсах давления подачи газа, имеющих прямоугольную вершину и предельно крутые фронты. Разработан и использован в практике проектирования новый комплекс дискретно-континуальных математических моделей для газодинамического расчета этой пневмосистемы, а также анализа сил трения и утечек газа во фторопластовых манжетных уплотнениях регуляторов. В моделях учтены новые эффекты: теплообмен газа со стенками полостей и трубопроводов; инерционность газа при его выпуске из баллона; фактор сжимаемости гелия; нагрев гелия при дросселировании; проникновение уплотняемого давления в зазор между манжетой и стенкой, и ряд других. После чего отклонение расчетных значений давления газа от результатов огневых испытаний составило менее 1% Создана и реализована расчетная методика исследования пневмосистемы на динамическую устойчивость и автоколебания. В методике использованы уточненные результаты гармонической линеаризации для колебаний расхода газа через дроссель и силы трения в манжете, а также новый метод расчета импеданса разветвленной системы трубопроводов. Выведено трансцендентное уравнение для частот и амплитуд свободных нелинейных колебаний системы и предложены методы его решения. Точность определения частот автоколебаний составила 2%. Получены аналитические соотношения для параметров пневмосистемы, обеспечивающие динамическую устойчивость или автоколебания малой амплитуды. Исследованы газодинамические характеристики металлорукава, используемого в дренажной системе лабораторного стенда для исследования и настройки системы. Разработана новая концепция и внедрена конструкция стенда, позволяющая экономить гелий при доводочных испытаниях системы. Выполнено расчетно-экспериментальное исследование системы, а его рекомендации по изменению параметров регулятора, снижающие колебательность и улучшающие другие динамические характеристики, внедрены на двигателе.The thesis for the scientific degree of the Candidate of Technical Sciences by specialty 05.05.17 – hydraulic machines and hydropneumatic units. – National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2017. The dissertation describes research of perfected pneumatic starting system of a main restartable liquid-propellant rocket engine destined for a launch vehicle upper stage. The starting system, which structure includes a part of the engine pneumatic unit, performs turbopump spin-up by supplying compressed helium to its turbine. A feature of the system is application of a pneumatically controlled helium pressure regulator. New complex of discrete-continual mathematical models is developed and implemented in the designing practice for the gas-dynamic analysis of this pneumatic system and analysis of friction forces and gas leaks through fluoroplastic lip-type seals of regulators. New computational method is proposed for the developed system’s dynamic stability research. The gas-dynamic characteristics of a metal hose are researched. New concept of the laboratory stand is developed and implemented to enable helium saving at development tests. Experimental-computational research of the pneumatic system is performed, recommendations of which are introduced into the engine in relation to the regulator parameters reducing oscillations and improving other dynamic characteristics.
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Атаманов, Юрий Леонидович. "Повышение эксплуатационных характеристик пневмоагрегатов ударного действия путем выбора их рациональной структуры и параметров." Thesis, НТУ "ХПИ", 2015. http://repository.kpi.kharkov.ua/handle/KhPI-Press/17042.
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Диссертация на соискание ученой степени кандидата технических наук по специальности 05.05.17 – гидравлические машины и гидропневмоагрегаты. - Национальный технический университет "Харьковский политехнический институт", Харьков, 2015.
Диссертационная работа посвящена решению научно-практической задачи улучшения эксплуатационных характеристик ударных пневмоагрегатов за счет исследования рабочего процесса в них и создания на этой основе методики параметрического анализа и синтеза этих агрегатов.
Предложена новая концепция управления ударным пневмоагрегатом, которая основывается на синхронизации работы ударного цилиндра и импульсного пневмораспределителя, осуществляющего рациональное управление контуром питания с тремя уровнями давления. Разработана универсальная нелинейная имитационная модель, как в размерной так и в безразмерной формах с выделением основных критериев динамического подобия. В основе модели лежат фундаментальные зависимости термодинамики тела переменной массы, а при нормировании уравнений использован принцип аналогичности тепломеханических систем. При создании линейной модели использованы новые подходы, которые заключаются в замене нелинейных зависимостей рационально подобранными секущими и построение предельно компактной имитационной модели ударного пневмоагрегата на основе уравнения равновесия механического аналога в виде разновидности одномассовой упруго-вязкостной модели Максвелла.
Одной из наиболее важных задач, поставленных и решенных на основе исследования имитационных моделей является выбор конструктивных параметров и давлений настроек контура питания обеспечивающих наиболее эффективное использование работоспособности сжатого воздуха при реализации удара. Результаты решения этих задач представлены как в аналитической форме так и в виде графиков. Причем благодаря использованию критериев динамического подобия с помощью этих графиков удается охватить практически всю область существования подобных пневмоагрегатов.
Предложенная инженерная методика расчетов кинематических, динамических и энергетических характеристик ударных пневмоагрегатов на основе решения как задач динамического анализа, так и задач динамического синтеза. Эти результаты также представлены в безразмерной форме в плоскости критериев динамического подобия и за счет этого охватывают обширную область существования ударных пневмоагрегатов т.е. позволяют распространить результаты исследований на целую группу динамически подобных пневмоагрегатов.
Адекватность имитационной модели и основные результаты теоретических исследований подтверждены путем натурных испытаний опытного макета ударного пневмоагрегата.Thesis for competition of scientific degree of candidate's of technical science on speciality 05.05.17 - hydraulic machines and hydropneumatic units. National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2012. The thesis is devoted to solving scientific and practical problem improve the performance of Pneumatic shock through research workflow and create them on this basis parametric methods of analysis and synthesis of these units. A new concept of control Pneumatic shock, based on the synchronization of stroke and pulsed pneumatic cylinder that provides power management control circuit with three levels of pressure. The universal nonlinear simulation model as well as dimensional and dimensionless forms of dynamic form the main criteria of similarity. When creating a linear model used new approaches which consist in replacing nonlinear dependencies January rational selection and construction is extremely compact Pneumatic shock simulation model based on equilibrium equation as a mechanical analogue kind-viscosity elastic models of Maxwell. The study defined the parameters of these models Pneumatic and conditions of operation that ensure the most effective implementation of the efficiency of compressed air in shock operations. The proposed engineering method of calculating kinematic, dynamic and energy characteristics Pneumatic shock based on solving problems as dynamic analysis and synthesis of dynamic problems.
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Атаманов, Юрій Леонідович. "Підвищення експлуатаційних характеристик пневмоагрегатів ударної дії шляхом вибору їх раціональної стуруктури і параметрів." Thesis, НТУ "ХПІ", 2015. http://repository.kpi.kharkov.ua/handle/KhPI-Press/17040.
Full textAbstract:
Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.05.17 – гідравлічні машини та гідропневмоагрегати. – Національний технічний університет "Харківський політехнічний інститут", Харків, 2015.
Дисертаційна робота присвячена вирішенню науково-практичної задачі покращення експлуатаційних характеристик ударних пневмоагрегатів за рахунок дослідження робочого процесу в них і створення на цій основі методики параметричного аналізу та синтезу цих агрегатів.
Запропонована нова концепція керування ударним пневмоагрегатом, яка ґрунтується на синхронізації роботи ударного циліндра та імпульсного пневморозподільника, що здійснює раціональне керування контуром живлення з трьома рівнями тиску. Розроблена універсальна нелінійна імітаційна модель, як в розмірній так і у безрозмірній формах з виокремленням основних критеріїв динамічної подоби. При створенні лінійної моделі використані нові підходи, які полягають у заміні нелінійних залежностей раціонально підібраними січними і побудові гранично компактної імітаційної моделі ударного пневмоагрегата на основі рівняння рівноваги механічного аналога у вигляді різновиду пружно-в'язкісної моделі Максвела.
У результаті дослідження цих моделей визначені параметри пневмоагрегата і умови його функціонування, що забезпечують найефективнішу реалізацію працездатності стисненого повітря при ударних операціях.
Запропонована інженерна методика розрахунку кінематичних, динамічних і енергетичних характеристик ударних пневмоагрегатів на основі вирішення як задач динамічного аналізу, так і задач динамічного синтезу.Thesis for competition of scientific degree of candidate's of technical science on speciality 05.05.17 - hydraulic machines and hydropneumatic units. National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2012. The thesis is devoted to solving scientific and practical problem improve the performance of Pneumatic shock through research workflow and create them on this basis parametric methods of analysis and synthesis of these units. A new concept of control Pneumatic shock, based on the synchronization of stroke and pulsed pneumatic cylinder that provides power management control circuit with three levels of pressure. The universal nonlinear simulation model as well as dimensional and dimensionless forms of dynamic form the main criteria of similarity. When creating a linear model used new approaches which consist in replacing nonlinear dependencies January rational selection and construction is extremely compact Pneumatic shock simulation model based on equilibrium equation as a mechanical analogue kind-viscosity elastic models of Maxwell. The study defined the parameters of these models Pneumatic and conditions of operation that ensure the most effective implementation of the efficiency of compressed air in shock operations. The proposed engineering method of calculating kinematic, dynamic and energy characteristics Pneumatic shock based on solving problems as dynamic analysis and synthesis of dynamic problems.
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Strydom, Anria. "Controllable suspension design using magnetorheological fluid." Diss., 2013. http://hdl.handle.net/2263/32545.
Full textAbstract:
The purpose of this study is to mitigate the compromise between ride comfort and handling of a
small single seat off-road vehicle known as a Baja. This has been achieved by semi-active control of
the suspension system containing controllable magnetorheological (MR) dampers and passive
hydro-pneumatic spring-damper units.
MR fluid is a viscous fluid whose rheological properties depend on the strength of the magnetic
field surrounding the fluid, and typically consists of iron particles suspended in silicone oil. When a
magnetic field is applied to the fluid, the iron particles become aligned and change the effective
viscosity of the fluid. The use of MR fluid in dampers provides variable damping that can be changed
quickly by controlling the intensity of the magnetic field around the fluid. Various benefits associated
with the use of MR dampers have led to their widespread implementation in automotive engineering.
Many studies on conventional vehicles in the existing literature have demonstrated the conflicting
suspension requirements for favourable ride comfort and handling. Generally, soft springs with low
damping are ideal for improved ride comfort, while stiff springs with high damping are required for
enhanced handling. This has resulted in the development of passive suspension systems that provide
either an enhanced ride quality or good drivability, often targeting one at the expense of the other.
The test vehicle used for this study is distinct in many ways with multiple characteristics that are
not commonly observed in the existing literature. For instance, the absence of a differential in the test
vehicle driveline causes drivability issues that are aggravated by increased damping.
The majority of existing MR damper models in the literature are developed for uniform excitation
and re-characterisation of model parameters is required for changes in input conditions. Although
recursive models are more accurate and applicable to a wider range of input conditions, these models
require measured force feedback which may not always be available due to limitations such as packaging constraints. These constraints required the development of alternative MR damper models
that can be used to prescribe the current input to the damper.
In this study parametric, nonparametric and recursive MR damper models have been developed
and evaluated in terms of accuracy, invertibility and applicability to random excitation. The
MR damper is used in parallel with passive damping as a certain amount of passive damping is always
present in suspension systems due to friction and elastomeric parts.
Most of the existing studies on suspension systems have been performed using linear two degree
of freedom vehicle models that are constrained to specific conditions. Usually these models are
implemented without an indication of the ability of these models to accurately represent the vehicles
that these studies are intended for.
For this study, a nonlinear, three-dimensional, 12 degrees of freedom vehicle model has been
developed to represent the test vehicle. This model is validated against experimental results for ride
comfort and handling. The MR damper models are combined with the model of the test vehicle, and
used in ride comfort and handling simulations at various levels of passive damping and control gains
in order to assess the potential impact of suspension control on the ride quality and drivability of the
test vehicle.
Simulation results show that lower passive damping levels can significantly improve the ride
comfort as well as the handling characteristics of the test vehicle. Furthermore, it is observed that
additional improvements that may be obtained by the implementation of continuous damping control
may not be justifiable due to the associated cost and complexity.Dissertation (MEng)--University of Pretoria, 2013.
Mechanical and Aeronautical Engineering
unrestricted
Book chapters on the topic "Pneumatic unit dynamics"
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Tomori, Hiroki, Tomohiro Koyama, Hiromitsu Nishikata, Akinori Hayasaka, and Ikumi Suzuki. "Developing a Flexible Segment Unit for Redundant-DOF Manipulator Using Bending Type Pneumatic Artificial Muscle." In ROMANSY 23 - Robot Design, Dynamics and Control, 272–79. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-58380-4_33.
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Cherkashenko, Mikhaylo, Oleksandr Gusak, Aleksandr Fatyeyev, Nadezhda Fatieieva, and Alexander Gasiyk. "Model of the Pneumatic Positional Unit with a Discrete Method for Control Dynamic Characteristics." In Lecture Notes in Mechanical Engineering, 81–90. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-06044-1_8.
Full textConference papers on the topic "Pneumatic unit dynamics"
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Andersen, David R., Graydon F. Booth, Anand R. Vithani, Som P. Singh, Anand Prabhakaran, Monique F. Stewart, and S. K. (John) Punwani. "Train Energy and Dynamics Simulator (TEDS): A State-of-the-Art Longitudinal Train Dynamics Simulator." In ASME 2012 Rail Transportation Division Fall Technical Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/rtdf2012-9418.
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Train safety and operational efficiency are enhanced by the ability to understand the behavior of trains under varying conditions. Under the direction of the Federal Railroad Administration (FRA), a longitudinal train dynamics and operation simulation software — Train Energy and Dynamics Simulator (TEDS) — has been developed. TEDS is capable of modeling modern train operations and equipment, and is an effective tool for studying train operations safety and performance as affected by equipment, train makeup, train handling, track conditions, operating practices and environmental conditions. TEDS simulates the dynamics of longitudinal train action and incorporates the dynamic effects of various different types of draft gears and end-of-car cushioning units including mismatched devices coupled together, the transient response of locomotive tractive and dynamic braking effort, as well as a fluid dynamic representation of the air brake system with the capability to model conventional pneumatic and ECP brake systems. The capabilities of TEDS are described and demonstrated with several examples. The validation effort undertaken is described at both the component and system level. Comparisons of TEDS simulations of impact tests with the test results are shown to verify the draft gear and end-of-car cushioning unit models. The air brake model predictions are verified by comparing brake rack test results to TEDS simulations of braking behavior.
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Porumamilla, H., Atul G. Kelkar, and Jerald M. Vogel. "Implementation of a Modified Skyhook Control on a Purely Pneumatic Semi-Active Suspension System." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-42230.
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The paper presents implementation of a modified skyhook control on a purely pneumatic suspension system comprising of an airspring, a pressure-differential causing geometry such as a sharp edged orifice and an accumulator, which utilizes the dynamics of compressible air flow through an orifice to inject damping into the suspension rather than heat dissipation as in suspensions with oil-base damper. A continuous-skyhook logic is implemented on the hardware built as a single degree of freedom system. For a head-to-head comparison, a contemporary semi-active suspension using an MR-damper is modeled. The airspring of this suspension is modeled from first principles of Thermodynamics and a new continuously differentiable function describing the force-velocity profiles of the MR-damper is developed. An evaluation of the sprung mass acceleration shows that the performance of the pneumatic suspension rivals that of the MR based unit for an arbitrarily chosen base excitation input. The modified Skyhook law proposed for producing pneumatic damping is shown to be able to inject sufficient damping (compared to MR-Damper), thereby off-setting the need for an additional oil damper.
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Bouldin, Bruce, Kiran Vunnam, Jose-Angel Hernanz-Manrique, and Laura Ambit-Marin. "CFD Analysis and Full Scale Testing of a Complex Auxiliary Power Unit Intake System." In ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/gt2011-46748.
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Auxiliary Power Units (APU’s) are gas turbine engines which are located in the tail of most commercial and business aircraft. They are designed to provide electrical and pneumatic power to the aircraft on the ground while the main propulsion engines are turned off. They can also be operated in flight, when there is a desire to reduce the load on the propulsion engines, such as during an engine-out situation. Given an APU’s typical position in the back of an airplane, the intake systems for APU’s can be very complex. They are designed to provide sufficient airflow to both the APU and the cooling system while minimizing the pressure losses and the flow distortion. These systems must perform efficiently during static operation on the ground and during flight at very high altitudes and flight speeds. An APU intake system has been designed for a new commercial aircraft. This intake system was designed using the latest Computational Fluid Dynamics (CFD) techniques. Several iterations were performed between the APU supplier and the aircraft manufacturer since each of their components affects the performance of the other. For example, the aircraft boundary layer impacts APU intake performance and an open APU flap impacts aircraft drag. To validate the effectiveness of the CFD analysis, a full scale intake rig was designed and built to simulate the tailcone of the aircraft on the ground. This rig was very large and very detailed. It included a portion of the tailcone and rudder, plus the entire APU and cooling intake systems. The hardware was manufactured out of fiberglass shells, stereolithogrophy components and machined plastic parts. Three different airflows for the load compressor, engine compressor and cooling system had to be measured and throttled. Fixed instrumentation rakes were located to measure intake induced pressure losses and distortion at the APU plenum and cooling ducts. Rotating pressure and swirl survey rakes were located at the load compressor and engine compressor eyes to measure plenum pressure losses and distortion. Static pressure taps measured the flow pattern along the intake and flap surfaces. The intake rig was designed to be flexible so that the impact of rudder position, intake flap position, APU plenum baffle position and compressor airflow levels could be evaluated. This paper describes in detail the different components of the intake rig and discusses the complexity of conducting a rig test on such a large scale. It also presents the impact of the different component positions on intake performance. These results were compared to CFD predicted values and were used to calibrate our CFD techniques. The effectiveness of using CFD for APU intake design and its limitations are also discussed.
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Jacazio, Giovanni, and Laura Gastaldi. "An Autonomous Pneumotronic System for Enhancing the Braking Capability of Long Freight Trains." In ASME 2009 Dynamic Systems and Control Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/dscc2009-2515.
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Trains brakes are pneumatically actuated and use the same pneumatic line for power and signal transmission. This simple architecture presents limits for long trains since the last vehicles brakes receive a very delayed command and the train speed must be limited. Solutions were proposed using a signal transmission line parallel to the pneumatic line. These systems, though effective, present drawbacks and are of difficult implementation as retrofits. A solution is described, which leaves the braking system unchanged, but reduces the time delay in the signal transmission by adding a pneumotronic unit at the pneumatic line end. This unit analyzes the pressure time history, recognizes the precursors of new braking commands and issues inputs to a valve at the pneumatic line end mirroring the commands to the master valve. The rapidity of the braking action is enhanced, thereby allowing a more uniform braking and a speed increase of long freight trains.
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Schaeffer, Hans W., and Atul G. Kelkar. "Fully Pneumatic Semi-Active Vibration Isolator Design and Analysis." In ASME 2017 Dynamic Systems and Control Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/dscc2017-5137.
Full textAbstract:
This paper presents a methodology of designing, modeling, and controlling a fully pneumatic semi-active vibration isolator system. The prototype vibration isolator system consists of an air spring, a variable orifice valve, and an accumulator which has the ability to simultaneously adjust the damping and natural frequency characteristics of the system. This paper presents a comprehensive work of modeling, hardware design, control design, and experimental validation of the proposed semi-active vibration isolation system. A higher fidelity model is obtained by complete characterization of nonlinear relationships between pressure versus volume and effective orifice area versus ride height. The performance of three semi-active controller designs — Linear Quadratic Impulse (LQI), Modified Skyhook, and Relative Displacement — is evaluated and compared experimentally using an OEM Peterbilt cabin suspension unit. The results demonstrate that the properly tuned semi-active suspension provides increased vibration isolation over the traditional passive cabin suspension design.
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Jouppila, V., and A. Ellman. "Effect of Load Disturbances on Multiplexed Force Control of McKibben Actuators." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-41806.
Full textAbstract:
Traditionally in fluid power systems each actuator is provided with its own control valve that is often quite an expensive and weighty component. By using multiplexed control, where a single control valve is shared among a number of actuators, it is possible to achieve cost and weight savings. The control system can be carried out with one pressure regulator and several high-speed on/off valves which form the multiplexer unit. The McKibben actuator has characteristics such as hermetic construction and almost frictionless operation which enable its use especially in force control applications. The muscle can maintain its pressure and thus the generated force for a relatively long time after it is disconnected from the pressure line. It has been proven [Jouppila & Ellman, 2006] that multiplexed force control of pneumatic muscles is an option for applications where multiple actuators have similar tasks with low dynamics. In this paper the effect of different load disturbances on the multiplexed force control system is investigated. The system is basically an open-loop configuration where the pressure regulator controls the system pressure. Thus, the system is sensitive to load variations because there is no feedback loop from the muscles. In the testing procedure the McKibben actuators with similar tasks are controlled with the multiplexing technique. The system behavior is studied when one of the muscles is displaced from its original position. The effects of using different frequencies and amplitudes for the load variation are studied. The purpose is to find the boundaries in which the pressure regulator is able to compensate the disturbance effects. Simulations are first used to investigate how sensitive the system is to the load variations. Also the pressure regulator’s capability for error compensation is studied. Actual measurements are used to verify the simulation results.
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Wen, Bor-Jiunn, Yung-Chiang Chung, and Tzong-Shi Liu. "Microfluidic Manipulation in Biochip System." In ASME 2008 Dynamic Systems and Control Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/dscc2008-2136.
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A transporting mechanism is designed for a micro total analysis system to move samples and reagents through microchannels that connect unit procedure components in the system. This study presents control design based on the 8051 microprocessor and implementation of biochip system comprising a pneumatic pumping actuator, feedback-signal photodiodes, and flowmeter. The new microfluid management technique successfully improved the efficiency of molecular biology reaction by increasing the velocity of the target nucleic acid molecules, which increases the effective collision into the probe molecules as the target molecules flow back and forth. Therefore, this hybridization chip is able to increase hybridization signal 6-fold and reduce non-specific target-probe binding and background noises within 30 minutes.
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Matveev, Valeriy, Yulia Novikova, Grigorii Popov, Oleg Baturin, and Evgenii Goriachkin. "Design and Operational Development a Pneumatic Braking System for a Gas-Turbine Units Test Bench." In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-64738.
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Each gas turbine engine must be tested after it has been produced or repaired. If the engine is used to generate power on the output shaft, its power must be utilized during the test process. To do this, pneumatic brake system can be applied. It allows to measure and utilize the power generated by the engine by using this power to drive a single compressor connected through the clutch with the output shaft of the engine under test. The process of gas-dynamic designing of the pneumatic braking system for a modernized gas-turbine engine NK-36ST is described in detail in this paper. Computational model was created by using Numeca Fine / Turbo and was verified using the experimental data of the baseline compressor. Also, research efforts which are aimed at improving the efficiency of the pneumatic braking system and increasing its gasdynamic stability were conducted. In particular, guide vane was added and the contours of its flow channel were modified. Also the exhaust nozzle was designed for the pneumatic braking system to ensure its work at the required operating points.
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Sokolov, I. J., V. I. Babitsky, and N. A. Halliwell. "Synthesis of Dynamical Structure of the Hydraulic Breaker With a Vibration-Free Handle." In ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-34667.
Full textAbstract:
An approach to the synthesis of a dynamical structure of the hand-held percussion machine with a vibration-free handle is presented. This is based on the consideration of the optimal dynamic conversion of energy in hand-held percussion machines founded as a solution of the equivalent problem of the optimal control [1]. For an accomplishment of the optimal regime a proper dynamic structure of the percussion machine as a multi-body vibro-impact system with one body (casing/handle) being free of vibration is found and investigated. Computer simulations and initial experiments validated the new approach. The main feature of the proposed design realising the synthesised structure is the use of a mechanism with zero differential stiffness. A hydro-pneumatic unit with zero stiffness was developed and tested. Theoretical recommendations have been applied to a commercial hydraulic breaker. A proper modification of the design and effective use of existing hydraulic power source provided a significant improvement in performance.
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Montonen, Jori, Erno Keskinen, Michel Cotsaftis, Juha Miettinen, and Wolfgang Seeman. "Dynamics of Single-Hit Pneumatic Test Drill for Pulse-Shaping Analysis of Impacting Waves." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-64835.
Full textAbstract:
Rock drilling is one of the elementary processes in mining industry. As larger diameter holes are drilled by hitting with units attached to the crone adapter down in the hole, the smaller blast holes are hit with units impacting the rod neck at rock surface. Key question in the performance and energy efficiency of the blast-hole drilling process is then, how completely the impact energy can be transmitted to the crone over the relatively long wave guide. There have been discussions about the effect of wave length and shape on to the penetration dynamics of rock drills. As the drilling process is a continuous set of hits following each other at relatively high constant period and the response is a random overlapped mixture of coming waves and returning reflected waves from multiple delayed hits, a detailed analysis of penetration dynamics is rather a complex problem. To overcome this difficulty, a full-scale half-manual test-drill has been designed and built to produce single hits for a systematic production and analysis of optimally shaped stress waves. The test-drill is an air-powered pneumatic gun, whose impact energy can be adjusted by setting the initial pressure level to correspond the desired end velocity of the piston. The design parameters, by which the pulse shape can be modified, are the length and the geometric profile of the piston body. The first problem to be faced is then to determine the optimal pulse shape for maximized penetration depth and the second one is to produce such desired shape by an optimal choice of the design parameters. The rig has been modelled using finite elements for the rod system and adiabatic state equations for the compressed and expanding air volumes. By modifying the design parameters, different penetration responses can be produced. In the first step, the model has been updated by means of experimental response measurements. The second step has been to modify the geometrical profiles of the piston body by starting from piece-vice linear and parabolic cross-sectional distributions. The output of the numerical analysis is to evaluate the penetration depth pro hit for different geometrical profiles. The most promising geometry has then been selected for the fabrication of the prototype piston. An experimental hitting test then completes the analysis, whose repeatability showed to be limited due to the random variation of the rock properties in the test bed. Test results obtained by using more regular concrete specimens exhibited reduced deviations in the responses, but the weakness in the test is the different damaging mechanism during the penetration. Another option is the use of an artificial load-sensing endsupport in order to produce a known boundary condition to replace the tool-rock resistance in the model-updating phase.