203 research outputs found
Aerial Robotics for Inspection and Maintenance
Aerial robots with perception, navigation, and manipulation capabilities are extending the range of applications of drones, allowing the integration of different sensor devices and robotic manipulators to perform inspection and maintenance operations on infrastructures such as power lines, bridges, viaducts, or walls, involving typically physical interactions on flight. New research and technological challenges arise from applications demanding the benefits of aerial robots, particularly in outdoor environments. This book collects eleven papers from different research groups from Spain, Croatia, Italy, Japan, the USA, the Netherlands, and Denmark, focused on the design, development, and experimental validation of methods and technologies for inspection and maintenance using aerial robots
Development of an autonomous system for assessment and prediction of structural integrity
Kako bi se osiguralo racionalnije, plansko održavanje prometne infrastrukture uz smanjenje troškova te u konačnici minimalizirao rizik od katastrofalnih posljedica, nužan je razvoj inovativnih rješenja u području održavanja građevina prometne infrastrukture. Kroz projekt ASAP razvija se sustav za autonomni pregled građevina, koji se zasniva na naprednim mjernim metodama integriranim na robota penjača i bespilotnu letjelicu. Cilj ovog rada je dati osvrt i upozoriti na nedostatke konvencionalnog načina ispitivanja materijala i konstrukcija za potrebu ocjene stanja, koji su bili osnovna motivacija okupljanja multidisciplinarnog tima kroz projekt ASAP. U radu su također prikazane mogućnosti i izazovi razvoja autonomnog sustava za pregled građevina, a sve u svrhu povećanja pouzdanosti i efikasnosti sustavnog pregleda građevina.Development of innovative solutions for the maintenance of transport infrastructure facilities is needed in order to ensure a more rational, planned and lower-cost maintenance of transport infrastructure, and to ultimately minimise the risk of catastrophic consequences. A system for an autonomous inspection of structures, based on advanced measuring methods integrated on a wall-climbing robot and an unmanned aerial vehicle, is currently developed in the scope of the ASAP project. The objective of this paper is to provide an overview and draw attention to disadvantages of conventional methods for testing materials and structures in order to assess their condition. This objective was the main motivation for forming a multidisciplinary team through the ASAP project. Possibilities and challenges in the development of an autonomous structural-assessment system are also presented in the paper, with the purpose of increasing the reliability and efficiency of systemic assessment of structures
Mobile Robotics
The book is a collection of ten scholarly articles and reports of experiences and perceptions concerning pedagogical practices with mobile robotics.“This work is funded by CIEd – Research Centre on Education, project UID/CED/01661/2019, Institute of Education, University of Minho, through national funds of FCT/MCTES-PT.
Aeronautics and space report of the President, 1982 activities
Achievements of the space program are summerized in the area of communication, Earth resources, environment, space sciences, transportation, aeronautics, and space energy. Space program activities of the various deprtments and agencies of the Federal Government are discussed in relation to the agencies' goals and policies. Records of U.S. and world spacecraft launchings, successful U.S. launches for 1982, U.S. launched applications and scientific satellites and space probes since 1975, U.S. and Soviet manned spaceflights since 1961, data on U.S. space launch vehicles, and budget summaries are provided. The national space policy and the aeronautical research and technology policy statements are included
Aeronautical enginnering: A cumulative index to a continuing bibliography (supplement 312)
This is a cumulative index to the abstracts contained in NASA SP-7037 (301) through NASA SP-7073 (311) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements have been compiled by the Center for AeroSpace Information of the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, foreign technology, contract number, report number, and accession number indexes
The Role of Vision Algorithms for Micro Aerial Vehicles
This work investigates the research topics related to visual aerial navigation in loosely structured and cluttered environments. During the inspection of the desired infrastructure the robot is required to fly in an environment which is uncertain and only partially structured because, usually, no reliable layouts and drawings of the surroundings are available.
To support these features, advanced cognitive capabilities are required, and
in particular the role played by vision is of paramount importance. The use
of vision and other onboard sensors such as IMU and GPS play a fundamental to
provide high level degree of autonomy to flying vehicles. In detail, the outline of
this thesis is organized as follows
• Chapter 1 is a general introduction of the aerial robotic field, the quadrotor
platform, the use of onboard sensors like cameras and IMU for autonomous
navigation. A discussion about camera modeling, current state of art on vision
based control, navigation, environment reconstruction and sensor fusion
is presented.
• Chapter 2 presents vision based control algorithms useful for reactive control
like collision avoidance, perching and grasping tasks. Two main contributions
are presented based on relative depth map and image based visual
servoing respectively.
• Chapter 3 discusses the use of vision algorithms for localization and mapping.
Compared to the previous chapter, the vision algorithm is more complex
involving vehicle’s poses estimation and environment reconstruction. An algorithm
based on RGB-D sensors for localization, extendable to localization
of multiple vehicles, is presented. Moreover, an environment representation
for planning purposes, applied to industrial environments, is introduced.
• Chapter 4 introduces the possibility to combine vision measurements and
IMU to estimate the motion of the vehicle. A new contribution based on Pareto Optimization, which overcome classical Kalman filtering techniques,
is presented.
• Chapter 5 contains conclusion, remarks and proposals for possible developments
Modelling and control of a twin rotor MIMO system.
In this research, a laboratory platform which has 2 degrees of freedom (DOF), the Twin
Rotor MIMO System (TRMS), is investigated. Although, the TRMS does not fly, it has
a striking similarity with a helicopter, such as system nonlinearities and cross-coupled
modes. Therefore, the TRMS can be perceived as an unconventional and complex "air
vehicle" that poses formidable challenges in modelling, control design and analysis and
implementation. These issues are the subject of this work.
The linear models for 1 and 2 DOFs are obtained via system identification techniques.
Such a black-box modelling approach yields input-output models with neither a priori
defined model structure nor specific parameter settings reflecting any physical
attributes. Further, a nonlinear model using Radial Basis Function networks is obtained.
Such a high fidelity nonlinear model is often required for nonlinear system simulation
studies and is commonly employed in the aerospace industry. Modelling exercises were
conducted that included rigid as well as flexible modes of the system. The approach
presented here is shown to be suitable for modelling complex new generation air
vehicles.
Modelling of the TRMS revealed the presence of resonant system modes which are
responsible for inducing unwanted vibrations. In this research, open-loop, closed-loop
and combined open and closed-loop control strategies are investigated to address this
problem. Initially, open-loop control techniques based on "input shaping control" are
employed. Digital filters are then developed to shape the command signals such that the
resonance modes are not overly excited. The effectiveness of this concept is then
demonstrated on the TRMS rig for both 1 and 2 DOF motion, with a significant
reduction in vibration.
The linear model for the 1 DOF (SISO) TRMS was found to have the non-minimum
phase characteristics and have 4 states with only pitch angle output. This behaviour
imposes certain limitations on the type of control topologies one can ado·pt. The LQG
approach, which has an elegant structure with an embedded Kalman filter to estimate
the unmeasured states, is adopted in this study.
The identified linear model is employed in the design of a feedback LQG compensator
for the TRMS with 1 DOF. This is shown to have good tracking capability but requires.
high control effort and has inadequate authority over residual vibration of the system.
These problems are resolved by further augmenting the system with a command path
prefilter. The combined feedforward and feedback compensator satisfies the
performance objectives and obeys the constraint on the actuator. Finally, 1 DOF
controller is implemented on the laboratory platform
Aeronautical engineering: A continuing bibliography with indexes (supplement 305)
This bibliography lists 239 reports, articles, and other documents recently introduced into the NASA scientific and technical information system. Subject coverage includes the following: the design, construction, and testing of aircraft and aircraft engines; aircraft components, equipment, and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics
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