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Articoli di riviste sul tema "Hovering platform"
1
Bak, Jeongae, Jong-Won Kim, Sangrok Jin, Jongwon Kim e TaeWon Seo. "Hovering Performance Improvement by Modifying COG of Underwater Robotic Platform". Journal of the Korean Society for Precision Engineering 32, n. 7 (1 luglio 2015): 661–66. http://dx.doi.org/10.7736/kspe.2015.32.7.661.
Testo completo
2
Aksenov, Alexey Y., Sergey V. Kuleshov e Alexandra A. Zaytseva. "An Application of Computer Vision Systems to Solve the Problem of Unmanned Aerial Vehicle Control". Transport and Telecommunication Journal 15, n. 3 (1 settembre 2014): 209–14. http://dx.doi.org/10.2478/ttj-2014-0018.
Testo completoAbstract (sommario):
Abstract The paper considers an approach for application of computer vision systems to solve the problem of unmanned aerial vehicle control. The processing of images obtained through onboard camera is required for absolute positioning of aerial platform (automatic landing and take-off, hovering etc.) used image processing on-board camera. The proposed method combines the advantages of existing systems and gives the ability to perform hovering over a given point, the exact take-off and landing. The limitations of implemented methods are determined and the algorithm is proposed to combine them in order to improve the efficiency.
3
Zhou, Xiangcong, Xiaogang Song, Deyuan Zhang e Yanqiang Liu. "Bionic Hovering Micro-Aerial Vehicle Using Array-Spiracle Wings". Machines 10, n. 11 (2 novembre 2022): 1016. http://dx.doi.org/10.3390/machines10111016.
Testo completoAbstract (sommario):
Hovering ability is the basis of fixed-point monitoring and tracking of an aircraft. Herein, we propose a new hovering vehicle inspired by bird feathers, with an airfoil composed of passive opening and closing feather units. Two wings of the prototype are vertically distributed and driven in anti-phase linear reciprocation. The lift is generated by the asymmetric flow of air caused by the opening and closing of the feather unit. The design of the vehicle is simple and can be incorporated into a large-area hovering platform for large loads. In this paper, the design and fabrication of the vehicle are described, along with an aerodynamic theoretical model of the vehicle kinematics. The correctness of the model was verified by numerical calculations and tests on the opening and closing characteristics of the plume unit. The opening and closing characteristics of the feather unit were investigated and revealed through controlled-variable experiments. An experimental prototype with a mass of 52 g was built. During preliminary flight tests, the vibration frequency was controlled to verify that the prototype was capable of hovering and vertical takeoff and landing.
4
KHO, I. Eng, Ahmad Windardi ALIYAZIS e Maulahikmah GALINIUM. "FRONT-END APPLICATION FOR MULTIPLE STOREFRONTS ECOMMERCE USING CROSS-PLATFORM TECHNOLOGY". BUSINESS EXCELLENCE AND MANAGEMENT 12, n. 1 (15 marzo 2022): 93–104. http://dx.doi.org/10.24818/beman/2022.12.1-07.
Testo completoAbstract (sommario):
Cross-platform framework is becoming more and more popular. Many giant tech companies have their own offering with different programming languages. With so many choices, sometimes it is difficult for a start-up developer to choose which framework they will use for their project. Therefore, this research aims to give insight for start-up developers on which cross-platform framework is better between Flutter and React Native by comparing their performance. This research achieved its goal by creating two identical mobile applications using Flutter and React Native and then comparing their performance using a theoretical framework that measures load time, average frame rate, and memory usage. The result of this testing is that Flutter has a shorter load time at 1.69 second compared to React Native at 4.26 second and lower memory usage at 6.52MB compared to React Native at 27.6MB. Their average frame rate is very comparable hovering around 60 frames per second. With faster load time and lower memory usage Flutter has better performance wise compared to React Native.
5
Jing, Yu, Fugui Qi, Fang Yang, Yusen Cao, Mingming Zhu, Zhao Li, Tao Lei, Juanjuan Xia, Jianqi Wang e Guohua Lu. "Respiration Detection of Ground Injured Human Target Using UWB Radar Mounted on a Hovering UAV". Drones 6, n. 9 (3 settembre 2022): 235. http://dx.doi.org/10.3390/drones6090235.
Testo completoAbstract (sommario):
As an important and basic platform for remote life sensing, unmanned aerial vehicles (UAVs) may hide the vital signals of an injured human due to their own motion. In this work, a novel method to remove the platform motion and accurately extract human respiration is proposed. We utilized a hovering UAV as the platform of ultra-wideband (UWB) radar to capture human respiration. To remove interference from the moving UAV platform, we used the delay calculated by the correlation between each frame of UWB radar data in order to compensate for the range migration. Then, the echo signals from the human target were extracted as the observed multiple range channel signals. Owing to meeting the independent component analysis (ICA), we adopted ICA to estimate the signal of respiration. The results of respiration detection experiments conducted in two different outdoor scenarios show that our proposed method could accurately separate respiration of a ground human target without any additional sensor and prior knowledge; this physiological information will be essential for search and rescue (SAR) missions.
6
Han, Jie, Weitao Jiang, Hongjian Zhang, Biao Lei, Lanlan Wang e Hongzhong Liu. "Submersible Soft‐Robotic Platform for Noise‐Free Hovering Utilizing Liquid–Vapor Phase Transition". Advanced Intelligent Systems 3, n. 1 (gennaio 2021): 2170013. http://dx.doi.org/10.1002/aisy.202170013.
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7
Jatsun, S., O. Emelyanova, B. Lushnikov, A. S. Martinez Leon, L. M. Mosquera Morocho, A. Pechurin e C. A. Nolivos Sarmiento. "Hovering control algorithm validation for a mobile platform using an experimental test bench". IOP Conference Series: Materials Science and Engineering 1027 (12 gennaio 2021): 012008. http://dx.doi.org/10.1088/1757-899x/1027/1/012008.
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8
Chen, Kun, Zhiwei Shi, Shengxiang Tong, Yizhang Dong e Jie Chen. "Aerodynamic interference test of quad tilt rotor aircraft in wind tunnel". Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 233, n. 15 (29 maggio 2019): 5553–66. http://dx.doi.org/10.1177/0954410019852827.
Testo completoAbstract (sommario):
There is an obvious aerodynamic interference problem that occurs for a quad tilt rotor in near-ground hovering or in the conversion operating condition. This paper presents an aerodynamic interference test of the quad tilt rotor in a wind tunnel. A 1:35 scale model of the quad tilt rotor is used in this test. To substitute for the ground, a moveable platform is designed in a low-speed open-loop wind tunnel to simulate different flight altitudes of the quad tilt rotor in hovering or forward flight. A rod six-component force balance is used to measure the loads on the aircraft, and the flow field below the airframe is captured using particle image velocimetry. The experimental results show that the ground effect is significant when the hover height above the ground is less than the rotor diameter of the quad tilt rotor aircraft, and the maximum upload of the airframe is approximately 12% of the total vertical thrust with the appearance of obvious fountain flow. During the conversion operating condition, the upload of the airframe is reduced compared with that in the hovering state, which is affected by rotor wake and incoming flow. The aerodynamic interference test results of the quad tilt rotor aircraft have important reference value in power system selection, control system design, and carrying capacity improvement with the advantage of ground effect.
9
Wang, Shengye, Haitao Wang, Wei Xiong e Guangfeng Guan. "Vibration Control of a Helicopter Rescue Simulator on a Flexible Base". Computational Intelligence and Neuroscience 2022 (25 aprile 2022): 1–10. http://dx.doi.org/10.1155/2022/7173421.
Testo completoAbstract (sommario):
The vibration compensation control of a hovering helicopter rescue simulator mounted on a crane beam is studied in this research. A Stewart platform is used as the motion generator of the helicopter simulation cabin and the vibration compensation device of the beam, simultaneously. This study describes how the dynamic model of the Stewart platform with consideration of the beam vibration is established. To determine the interference of the Stewart platform motion control in the special application of a large component flexible base requiring large-scale movement, a hybrid vibration controller composed of a feed-forward compensation module and a PD (proportional-derivative) feedback control module is designed. The experimental results show that this method can effectively compensate for the beam vibration and improve the accuracy of the motion reproduction of a helicopter simulation cabin.
10
Wang, Shengye, Haitao Wang, Wei Xiong e Guangfeng Guan. "Vibration Control of a Helicopter Rescue Simulator on a Flexible Base". Computational Intelligence and Neuroscience 2022 (25 aprile 2022): 1–10. http://dx.doi.org/10.1155/2022/7173421.
Testo completoAbstract (sommario):
The vibration compensation control of a hovering helicopter rescue simulator mounted on a crane beam is studied in this research. A Stewart platform is used as the motion generator of the helicopter simulation cabin and the vibration compensation device of the beam, simultaneously. This study describes how the dynamic model of the Stewart platform with consideration of the beam vibration is established. To determine the interference of the Stewart platform motion control in the special application of a large component flexible base requiring large-scale movement, a hybrid vibration controller composed of a feed-forward compensation module and a PD (proportional-derivative) feedback control module is designed. The experimental results show that this method can effectively compensate for the beam vibration and improve the accuracy of the motion reproduction of a helicopter simulation cabin.
Tesi sul tema "Hovering platform"
1
Camlica, Fahri Bugra. "Demonstration Of A Stabilized Hovering Platform For Undergraduate Laboratory". Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605772/index.pdf.
Testo completoAbstract (sommario):
This research work covers the design, manufacture and testing of an unmanned aerial vehicle for the purpose of testing various control systems by undergraduate students in the laboratory environment. The aerial vehicle under
consideration is a four-rotor propeller powered. Aluminum rod based mechanical structure is preferred. The stabilization of the hovering vehicle in its rotational axes in the air and navigation about the yaw axis are the accomplished goals of this study. The aerial vehicle is run in real time by using Matlab 6.5 Software&rsquos xPc module. The linear quadratic regulator and PD controllers are utilized to stabilize the aerial vehicle in its rotation axes. To eliminate the measurement noise generated by the sensors, low-pass second order transfer function is designed and its implementation to real time experiments is discussed.
2
Roberts, James Francis. "Design of an Autonomous Hovering Miniature Air Vehicle as a Flying Research Platform". Thesis, The University of Sydney, 2008. http://hdl.handle.net/2123/2773.
Testo completoAbstract (sommario):
This thesis, by developing a Miniature Aerial Vehicle (MAV) hovering platform, presents a practical solution to allow researchers and students to implement their theoretical methods for guidance and navigation in the real world. The thesis is not concerned with the development of guidance and navigation algorithms, nor is it concerned with the development of external sensors. There have been some recent advances in guidance and navigation towards developing algorithms and simple sensors for MAVs. The task of developing a platform to test such advancements is the subject of this thesis. It is considered a difficult and time consuming process due to the complexities of autonomous flight control and the strict size, weight and computational requirements of this type of system. It would be highly beneficial to be able to buy a platform specifically designed for this task that already possesses autonomous hovering capability and the expansion connectivity for interfacing your own custom developed sensors and algorithms. Many biological and computer scientists would jump at the opportunity to maximize their research by real world implementation. The development of such a system is not a trivial task. It requires a great deal of understanding in a broad range of fields including; Aeronautical, Microelectronic, Mechanical, Computer and Embedded Software Engineering in order to create a successful prototype. The challenge of this thesis was to design a research platform to enable easy implementation of external sensors and guidance algorithms, in a real world environment for research and education. The system is designed so it could be used for a broad range of testing experiments. After extensive research in current MAV and avionics design it became obvious in several areas the best available products were not sufficient to meet the needs of the proposed platform. Therefore it was necessary to custom design and build; sensors, a data acquisition system and a servo controller. The latter two products are available for sale by Jimonics (www.jimonics.com). It was then necessary to develop a complete flight control system with integrated sensors, processor and wireless communications network which is called ‘The MicroBrain’. ‘The MicroBrain’ board measures only 45mm x 35mm x 11mm and weighs ~11 grams. The coaxial contra-rotating MAV platform design provides a high level of mechanical stability to help minimise the control system complexity. The platform was highly modified from a commercially available remotely controlled helicopter. The system incorporates a novel collision protection system that was designed to also double as a mounting place for external sensors around its perimeter. The platform equipped with ‘The MicroBrain’ is capable of fully autonomous hover. This provides a great base for testing guidance and navigational sensors and algorithms by decoupling the difficult task of platform design and low-level stability control. By developing a platform with these capabilities the researcher can now focus on the guidance and navigation task, as the difficulties in developing a custom platform have been taken care of. This therefore promotes a faster evolution of guidance and navigational control algorithms for MAVs.
3
Wang, Chin-Hsiung, e 王進雄. "Design of Test Platform and Hovering Control for Unmanned Helicopters". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/99463548833687743460.
Testo completoAbstract (sommario):
碩士國立屏東科技大學
車輛工程系所
98
A remote-control helicopter has six degrees of freedom and its dynamics is very nonlinear, which make the design of its controller very complicated. Without an autopilot, it is not easy to control an RC helicopter and crash may happen if an improper action is taken. In this research, a fuzzy controller is developed to do the hovering control of the helicopter. The controller design is validated by computer simulations and experimental tests on a platform. The simulations have been done under MATLAB/SIMULINK environment. The experimental tests were exercised with MATLAB XPC real-time control kernel. The test results of the fuzzy controller were also compared with those of an adaptive controller. It can be concluded that the advantage of the fuzzy controller design is its simplicity compared with the good adaptation of environment changes for the adaptive controller.
4
Roberts, James Francis. "Design of an Autonomous Hovering Miniature Air Vehicle as a Flying Research Platform". 2008. http://hdl.handle.net/2123/2773.
Testo completoAbstract (sommario):
Master of Engineering (Research)This thesis, by developing a Miniature Aerial Vehicle (MAV) hovering platform, presents a practical solution to allow researchers and students to implement their theoretical methods for guidance and navigation in the real world. The thesis is not concerned with the development of guidance and navigation algorithms, nor is it concerned with the development of external sensors. There have been some recent advances in guidance and navigation towards developing algorithms and simple sensors for MAVs. The task of developing a platform to test such advancements is the subject of this thesis. It is considered a difficult and time consuming process due to the complexities of autonomous flight control and the strict size, weight and computational requirements of this type of system. It would be highly beneficial to be able to buy a platform specifically designed for this task that already possesses autonomous hovering capability and the expansion connectivity for interfacing your own custom developed sensors and algorithms. Many biological and computer scientists would jump at the opportunity to maximize their research by real world implementation. The development of such a system is not a trivial task. It requires a great deal of understanding in a broad range of fields including; Aeronautical, Microelectronic, Mechanical, Computer and Embedded Software Engineering in order to create a successful prototype. The challenge of this thesis was to design a research platform to enable easy implementation of external sensors and guidance algorithms, in a real world environment for research and education. The system is designed so it could be used for a broad range of testing experiments. After extensive research in current MAV and avionics design it became obvious in several areas the best available products were not sufficient to meet the needs of the proposed platform. Therefore it was necessary to custom design and build; sensors, a data acquisition system and a servo controller. The latter two products are available for sale by Jimonics (www.jimonics.com). It was then necessary to develop a complete flight control system with integrated sensors, processor and wireless communications network which is called ‘The MicroBrain’. ‘The MicroBrain’ board measures only 45mm x 35mm x 11mm and weighs ~11 grams. The coaxial contra-rotating MAV platform design provides a high level of mechanical stability to help minimise the control system complexity. The platform was highly modified from a commercially available remotely controlled helicopter. The system incorporates a novel collision protection system that was designed to also double as a mounting place for external sensors around its perimeter. The platform equipped with ‘The MicroBrain’ is capable of fully autonomous hover. This provides a great base for testing guidance and navigational sensors and algorithms by decoupling the difficult task of platform design and low-level stability control. By developing a platform with these capabilities the researcher can now focus on the guidance and navigation task, as the difficulties in developing a custom platform have been taken care of. This therefore promotes a faster evolution of guidance and navigational control algorithms for MAVs.
Libri sul tema "Hovering platform"
1
National Aeronautics and Space Administration (NASA) Staff. Bias Momentum Sizing for Hovering Dual-Spin Platforms. Independently Published, 2018.
Cerca il testo completoCapitoli di libri sul tema "Hovering platform"
1
Norton, Bryan G. "Biological Diversity". In Toward Unity among Environmentalists. Oxford University Press, 1995. http://dx.doi.org/10.1093/oso/9780195093971.003.0014.
Testo completoAbstract (sommario):
As a philosopher who has written on the subject of endangered species policy, I am asked from time to time to join a panel discussion on “the value of biological diversity.” Consider a representative example: At the National Forum on Biodiversity, a 1986 conference organized by the Smithsonian Institution and the National Academy of Sciences, I shared the platform with three resource economists and one ecologist. Everyone on the platform agreed that biological diversity has great value; the discussion focused on the question, can that value be quantified in dollar terms? I quickly perceived that I was in the middle of a polarized situation. The economists were there to demonstrate the efficacy of their methods for representing the value of wild species as dollars; the ecologist scoffed at these attempts as irrelevant at best and, at worst, as a symptom of moral depravity. Hovering in the background of discussions like this are celebrated examples such as that of the snaildarter and the Tellico Dam. In that case, the Supreme Court halted work on an almost-completed dam because it would have flooded the only known habitat of the snaildarter, a three-inch member of the perch family. The politically tortured case of the tiny snaildarter illustrates the dilemma environmentalists face in defending biological resources. Environmentalists initially opposed the Tennesee Valley Authority’s plans to dam one of the last free-flowing stretches of the Little Tennessee River because it would destroy white-water canoeing, flood natural ecological systems, and destroy anthropologically important Indian burial sites. Environmentalists made little headway, initially, as the bureaucratic processes ground forward and construction of the dam was begun. Then, in early 1976, in a dramatic development, biologists discovered a hitherto unknown species, the snaildarter, living in the waters upstream from the dam. Since the snaildarter spawned in shallow, fast-moving waters, the dam threatened to wipe out a distinctive form of life. Environmental economists, anxious to use their quantificational tools, saw the Tellico Dam as a case in which assigning a dollar value to a threatened species might tip the scales in an aggregation of costs and benefits of proposed projects.
2
Raza, Gauhar. "Precariat: narrow definition, discourse and reality". In Savoirs de la Précarité / knowledge from precarity, 249–57. Editions des archives contemporaines, 2020. http://dx.doi.org/10.17184/eac.3342.
Testo completoAbstract (sommario):
The discourse initiated by Guy Standing, on the ‘Precariat’, a few years back, was embedded in economic debates on ‘class’. He, in the preface of his book ‘The Precariate: The new Dangerous Class’, wrote that Precariat is a class in making (Standing G, 2011). He uses the word ‘Class’ in the Marxian sense. He suggests that the neoliberalism agenda embraced by almost all countries, to a greater or lesser extent, deliberately shifted the burden of ‘risk’ and ‘insecurity’ on to the ‘working class and their families’. As a result millions of workers were pushed into the brutal market without ‘an anchor of stability’. Standing goes on to, dramatically, warn politicians and civil society that ‘There is a danger that, unless the precariat is understood, its emergence could lead society towards a politics of inferno.’ He further adds that this class is global, angry and anxious, and ‘prone to listen to ugly voices, and use their vote and money to give those voices a political platform of increasing influence’.Marxist scholars reacted sharply. For example Eric Olin Wright, presented ‘a Marxist critique of this reconceptualization on two principle grounds: first, that the material interests of people in the precariat and in the working class are not sufficiently opposed to each other for these to constitute two distinct classes; and second, that across the various segments of the precariat the optimal strategies for securing a livelihood are not sufficiently unified for the precariat as a whole to constitute a class. ----In the case of the precariat, the different segments identified by Standing have sharply different strategies of survival and advancement.’ And thus, he concluded, there is no separate class, which can be categorized as ‘Precariate’. Those who have faced the burden of recent global economic disasters, and were pushed towards the base of a pecuniary pyramid can be designated as ‘proletariat class’, at the best, depending upon their class consciousness and interest. The debate plunged into a terrain which focused on whether there is an emerging class, that too global in nature, which has common interest and enough cementing factors to represent common and universal class interest and consciousness, or not. Though the debate is yet to resolve major issues hovering around economic categories and their relationship with social and cultural factors, it cannot be denied that manmade and natural disasters often put sections of humanity into ‘precarious’ condition. Citizens, collectively and individually respond to a given ‘precarity’ in varied ways.This paper, while scanning the debate on ‘precariat’ attempts to develop a broad framework for examining the causes and nature of precarity, enlarges its definition, discusses sources, target populations, modes of operation through which precarity is introduced in any society and levels at which precarity operates. The article aims to scrutinize as to how, when the power balance is disturbed in society, ruling classes use physical force as an instrument of spreading fear among the agents of change. The article also makes an attempt to reflect on how the intellectuals, scientists, science communicators and journalist under the shadow of ‘fascistic regimes’ are pushed to the realm of ‘precarity’ and freedom of expression is threatened. The last section of the article gives some concrete examples of how ‘precariat’ responds to situations of precarity and tries to build broad alliances to resist the causal forces
Atti di convegni sul tema "Hovering platform"
1
Jin, Sangrok, Jihoon Kim, Jongwon Kim e TaeWon Seo. "Hovering underwater robotic platform with four tilting thrusters". In 2014 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM). IEEE, 2014. http://dx.doi.org/10.1109/aim.2014.6878303.
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2
Santana, Lucas V., Alexandre S. Brandao, Mario Sarcinelli-Filho e Ricardo Carelli. "Hovering control of a miniature helicopter attached to a platform". In 2011 IEEE 20th International Symposium on Industrial Electronics (ISIE). IEEE, 2011. http://dx.doi.org/10.1109/isie.2011.5984508.
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3
Rong, Yu, Andrew Herschfelt, Jacob Holtom e Daniel W. Bliss. "Cardiac and Respiratory Sensing from a Hovering UAV Radar Platform". In 2021 IEEE Statistical Signal Processing Workshop (SSP). IEEE, 2021. http://dx.doi.org/10.1109/ssp49050.2021.9513771.
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4
Rehman, Faheem Ur, Enrico Anderlini e Giles Thomas. "Development of a Simulation Platform for Underwater Transportation using Two Hovering Autonomous Underwater Vehicles". In International Conference of Control, Dynamic Systems, and Robotics. Avestia Publishing, 2019. http://dx.doi.org/10.11159/cdsr19.138.
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Dumas, Antonio, Michele Trancossi e Stefano Anzillotti. "An Airship Design Methodology Based on Available Solar Energy in Low Stratosphere". In ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-38931.
Testo completoAbstract (sommario):
The actual applicative research concerning airships and their use as HAP (High Altitude Platforms for telecommunications and military use) presents new applicative hypothesis of these systems, also concerning energetic high quote production. Authors present the energetic balance of a high quote photovoltaic platform with capability of static hovering realized by electric powered propellers. This is the first step trough the design of the P. S. I. C. H. E. (Photovoltaic Space Island for Conversion of Hydrogen as Energy vector) airship concept: a stratospheric airship which could be considered a platform for hydrogen and oxygen production by photovoltaic. It investigates the behaviour of a similar platform operating at altitudes between 10 and 20 km, positioned at 45° latitude north [1, 2]. This paper analyses the design process for a High Altitude Platform based on photovoltaic energy caption, but the process could be generalized in order to be applied to any airship project. It is considers airship shapes equipped with large PV array that covers energy request during the day. Surplus in power supplies electrolyser equipments for hydrogen and oxygen production from water, which could be captured by atmospheric humidity or brought by an auxiliary airship. Hydrogen and Oxygen are compressed and stored in gas cylinders. With insufficient solar irradiance, with severe wind conditions and during the night, a fuel cell system fed by hydrogen and oxygen tanks supplies power requirements. The Standard Atmosphere Model is used to evaluate PV performance at various operative altitudes. A propulsion system with electric motors grants airship manoeuvrability and hovering. Energy balance of PV-hydrogen energy supply system has been analyzed for three airship shapes with equal volume with concern of overabundant hydrogen and oxygen production. Total weight and payload are calculated in relation to altitude. Storage tanks dimensions and products ground transportation frequency has been estimated. Hydrogen annual production for PV square meter has been evaluated in relation to ground production at the same latitude.
6
Aihaitijiang, A., e Cagdas D. Onal. "Development and Experimental Evaluation of a Quad-Tilt-Wing Flying Robot Platform". In ASME 2019 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/detc2019-98500.
Testo completoAbstract (sommario):
Abstract In this paper, we present the mechanical design and control system of a new indoor and outdoor Quad-Tilt-Wing flying robot. The proposed flying robot can achieve vertical takeoff, hovering, and long duration horizontal high-speed flight. All of these flight modes can be achieved by simply changing the angle of the rotors and wings by a tilt mechanism. We present the details on design and prototyping, the attitude control system, and experimental results, including wind-tunnel experiments, full flight tests, and performance tests. The experimental results show that our Quad-Tilt-Wing flying robot successfully achieves full conversion flight: vertical and rapid takeoff, high-speed cruise, and vertical landing. Performance test results show that during horizontal flight, the wings generate lift and effectively reduce energy use compared to a fixed quad rotor architecture. Consequently, the proposed platform combines unique features of multi-rotor and fixed wing systems to achieve long-duration flight with low-energy compared to a conventional multi-rotor UAV.
7
Tatoglu, Akin. "Parameter Identification and Closed Loop Control of a Flywheel Mounted Hovering Robot". In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-71877.
Testo completoAbstract (sommario):
A prototype of a hovering multi-terrain mobile robot platform that makes use of a flywheel for stabilization and heading control for rapid maneuverability was developed and presented in a prior paper. It was shown that flywheel stored energy could be transferred to the overall body to generate rapid angular motion once wheel is instantaneously stopped. Solution improved localization accuracy and reduced the overall sensitivity with respect to external disturbances such as non-flat terrain. In this paper, we present a feedback control system to measure dynamic parameters before and after the wheel is stopped. System is designed to follow a predefined path plan and instantaneous torque change causes oscillation after a waypoint is reached. To address this issue, we updated system with an inertial measurement unit (IMU) as a feedback sensor. Then, we investigate the feedback control of individual forward thrust vectors as well as wheel braking timing to minimize amplitude of transient response oscillation and to reduce the steady-state error to an acceptable level that differential drive fans could compensate this error and correct the heading after the rotation around a waypoint occurs. In addition to that, previous mechanical system could transfer all energy stored at once and was not adjustable. In this research, we also investigate varying amount of angular inertia generated by fans and wheel individually and together. To do so, system is modified with stronger forward thrusters. Prior to running the system with a full dynamic model with real mechanism, we implemented a simulation to empirically extract system parameters and adjust controller gains to follow a predefined path with open and closed loop control schemas with objective of minimizing localization error. Finally system is tested with real mechanism. Governing equations, simulation and empirical results comparison are presented and generated trajectories of various simulation and real world settings are listed. Test results verify that, with a closed loop control system, overshoot and total error about a waypoint can be minimized to an acceptable level at and after transient response phase.
8
Lee, Jameson Y., Zachary Cook, Alexander Barzilov e Woosoon Yim. "Control of an Aerial Manipulator With an On-Board Balancing Mechanism". In ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-66976.
Testo completoAbstract (sommario):
Multirotor Unmanned Aerial Systems (UAS) are highly mobile in flight and possess stable hovering capabilities. Because of their unique flight characteristics, the utilization of the platform for active tasks such as aerial manipulation is highly attractive. Much work has been done in recent years towards the implementation of multirotor for aerial manipulation, however, progress in the field has been slow due to the many challenges involved in the implementation of robust rotor control. In an attempt to reduce the effects of the manipulator, a technique for disturbance rejection using a novel balancing mechanism is proposed. In this paper, the dynamic equations of a coupled multirotor and manipulator are analyzed as a single body for use in the attitude control of the platform. By mounting the mechanism, the platform effectively gains marginal control over the positioning of its center of gravity relative to a body fixed frame. It can be shown that the increased mobility can be utilized to reduce rotor saturation for any given flight condition and improve the effectiveness of previously developed rotor control methods.
9
Metni, Najib A. "Sensor Fusion for Attitude and Bias Estimation for a VTOL UAV". In ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2010. http://dx.doi.org/10.1115/esda2010-24989.
Testo completoAbstract (sommario):
In this paper, a nonlinear complementary filter is presented to estimate the attitude of a Vertical Take Off and Landing Unmanned Aerial Vehicle (VTOL UAV). The measurements are taken from a low-cost IMU (Inertial Measurement Unit) which consists of 3-axis accelerometers, 3-axis gyroscopes and 3-axis magnetometers. From the proposed estimators, the full orientation matrix R will be retrieved. The proposed observers will estimate the instantaneous quaternions as well as the gyroscope bias. This representation of orientation by the rotation matrix and quaternions allows overcoming the problem of singularities that appear in local parametrization such as Euler angles. Therefore, both estimators may be used to describe any kind of 3-D motion. Convergence of the two observers is theoretically proved and simulations are conducted taking data from a real platform in hovering flight conditions.
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Brech, Dale E., Joseph D. St. Amand, Randy C. Hoover, Jeff S. McGough e Mark Bedillion. "Design and Development of a Vector Thrusting Quadrotor for Minimally Induced Pitch and Roll Motions". In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-88408.
Testo completoAbstract (sommario):
Due to its hovering capabilites and maneuverability, the quadrotor provides an excellent platform for unmanned systems and robotics research. Localization of the vehicle is typically done via laser ranging or photometric and depth cameras. The design of the quadrotor introduces a problem, however, when it is to travel parallel to the ground plane. Due to the rigid body of the quadrotor and the fixed orientation of the thrusters it is impossible for the quadrotor to undergo this motion without inducing a change in the pitch and/or roll orientation. This introduces a problem in finding the true orientation at which sensor measurements are taken, requiring advanced computer vision algorithms, mechanical gimbal systems or other means to compensate for the motion. This paper focuses on the design of a quadrotor that has the capability to travel parallel to the ground plane while minimizing the induced pitch and roll motion. The unique contribution to the quadrotor design is to allow each of the quadrotor arms to rotate about their respective horizontal axis in order to accomplish thrust vectoring of the individual motors. By controlling both the magnitude and direction of each of the motor thrusts, pure translational maneuvers are possible without inducing pitch and/or roll motions. Simulation results are presented as well as the controller used to govern the behavior of the craft.
Rapporti di organizzazioni sul tema "Hovering platform"
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Bruder, Brittany L., Katherine L. Brodie, Tyler J. Hesser, Nicholas J. Spore, Matthew W. Farthing e Alexander D. Renaud. guiBath y : A Graphical User Interface to Estimate Nearshore Bathymetry from Hovering Unmanned Aerial System Imagery. Engineer Research and Development Center (U.S.), febbraio 2021. http://dx.doi.org/10.21079/11681/39700.
Testo completoAbstract (sommario):
This US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, technical report details guiBathy, a graphical user interface to estimate nearshore bathymetry from imagery collected via a hovering Unmanned Aerial System (UAS). guiBathy provides an end-to-end solution for non-subject-matter-experts to utilize commercia-off-the-shelf UAS to collect quantitative imagery of the nearshore by packaging robust photogrammetric and signal-processing algorithms into an easy-to-use software interface. This report begins by providing brief background on coastal imaging and the photogrammetry and bathymetric inversion algorithms guiBathy utilizes, as well as UAS data collection requirements. The report then describes guiBathy software specifications, features, and workflow. Example guiBathy applications conclude the report with UAS bathymetry measurements taken during the 2020 Atlantic Hurricane Season, which compare favorably (root mean square error = 0.44 to 0.72 m; bias = -0.35 to -0.11 m) with in situ survey measurements. guiBathy is a standalone executable software for Windows 10 platforms and will be freely available at www.github.com/erdc.