3,209 research outputs found
Modelling and analyzing adaptive self-assembling strategies with Maude
Building adaptive systems with predictable emergent behavior is a challenging task and it is becoming a critical need. The research community has accepted the challenge by introducing approaches of various nature: from software architectures, to programming paradigms, to analysis techniques. We recently proposed a conceptual framework for adaptation centered around the role of control data. In this paper we show that it can be naturally realized in a reflective logical language like Maude by using the Reflective Russian Dolls model. Moreover, we exploit this model to specify, validate and analyse a prominent example of adaptive system: robot swarms equipped with self-assembly strategies. The analysis exploits the statistical model checker PVeStA
Modelling and analyzing adaptive self-assembling strategies with Maude
Building adaptive systems with predictable emergent behavior is a challenging task and it is becoming a critical need. The research community has accepted the challenge by introducing approaches of various nature: from software architectures, to programming paradigms, to analysis techniques. We recently proposed a conceptual framework for adaptation centered around the role of control data. In this paper we show that it can be naturally realized in a reflective logical language like Maude by using the Reflective Russian Dolls model. Moreover, we exploit this model to specify, validate and analyse a prominent example of adaptive system: robot swarms equipped with self-assembly strategies. The analysis exploits the statistical model checker PVeStA
Advanced flight control system study
A fly by wire flight control system architecture designed for high reliability includes spare sensor and computer elements to permit safe dispatch with failed elements, thereby reducing unscheduled maintenance. A methodology capable of demonstrating that the architecture does achieve the predicted performance characteristics consists of a hierarchy of activities ranging from analytical calculations of system reliability and formal methods of software verification to iron bird testing followed by flight evaluation. Interfacing this architecture to the Lockheed S-3A aircraft for flight test is discussed. This testbed vehicle can be expanded to support flight experiments in advanced aerodynamics, electromechanical actuators, secondary power systems, flight management, new displays, and air traffic control concepts
Flexible Composition of Robot Logic with Computer Vision Services
Vision-based robotics is an ever-growing field within industrial automation. Demands for greater flexibility and higher quality motivate manufacturing companies to adopt these technologies for such tasks as material handling, assembly, and inspection. In addition to the direct use in the manufacturing setting, robots combined with vision systems serve as highly flexible means for realization of prototyping test-beds in the R&D context.Traditionally, the problem areas of robotics and computer vision are attacked separately. An exception is the study of vision-based servo control, the focus of which constitutes control-theoretic aspects of vision-based robot guidance under assumption that robot joints can be controlled directly. The missing part is a systemic approach to implementing robotic application with vision sensing given industrial robots constrained by their programming interface. This thesis targets the development process of vision-based robotic systems in an event-driven environment. It focuses on design and composition of three functional components: (1) robot control function, (2) image acquisition function, and (3) image processing function. The thesis approaches its goal by a combination of laboratory results, a case study of an industrial company (Kongsberg Automotive AS), and formalization of computational abstractions and architectural solutions. The image processing function is tackled with the application of reactive pipelines. The proposed system development method allows for smooth transition from early-stage vision algorithm prototyping to the integration phase. The image acquisition function in this thesis is exposed in a service-oriented manner with the help of a flexible set of concurrent computational primitives. To realize control of industrial robots, a distributed architecture is devised, which supports composability of communication-heavy robot logic, as well as flexible coupling of the robot control node with vision services
An intelligent knowledge based cost modelling system for innovative product development
This research work aims to develop an intelligent knowledge-based system for product
cost modelling and design for automation at an early design stage of the product
development cycle, that would enable designers/manufacturing planners to make more
accurate estimates of the product cost. Consequently, a quicker response to customers’
expectations. The main objectives of the research are to: (1) develop a prototype system
that assists an inexperienced designer to estimate the manufacturing cost of the product,
(2) advise designers on how to eliminate design and manufacturing related conflicts that
may arise during the product development process, (3) recommend the most economic
assembly technique for the product in order to consider this technique during the design
process and provide design improvement suggestions to simplify the assembly
operations (i.e. to provide an opportunity for designers to design for assembly (DFA)),
(4) apply a fuzzy logic approach to certain cases, and (5) evaluate the developed
prototype system through five case studies.
The developed system for cost modelling comprises of a CAD solid modelling system,
a material selection module, knowledge-based system (KBS), process optimisation
module, design for assembly module, cost estimation technique module, and a user
interface. In addition, the system encompasses two types of databases, permanent
(static) and temporary (dynamic). These databases are categorised into five separate
groups of database, Feature database, Material database, Machinability database,
Machine database, and Mould database.
The system development process has passed through four major steps: firstly,
constructing the knowledge-based and process optimisation system, secondly
developing a design for assembly module. Thirdly, integrating the KBS with both
material selection database and a CAD system. Finally, developing and implementing a
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fuzzy logic approach to generate reliable estimation of cost and to handle the
uncertainty in cost estimation model that cannot be addressed by traditional analytical
methods.
The developed system has, besides estimating the total cost of a product, the capability
to: (1) select a material as well as the machining processes, their sequence and
machining parameters based on a set of design and production parameters that the user
provides to the system, and (2) recommend the most economic assembly technique for a
product and provide design improvement suggestion, in the early stages of the design
process, based on a design feasibility technique. It provides recommendations when a
design cannot be manufactured with the available manufacturing resources and
capabilities. In addition, a feature-by-feature cost estimation report was generated using
the system to highlight the features of high manufacturing cost. The system can be
applied without the need for detailed design information, so that it can be implemented
at an early design stage and consequently cost redesign, and longer lead-time can be
avoided. One of the tangible advantages of this system is that it warns users of features
that are costly and difficult to manufacture. In addition, the system is developed in such
a way that, users can modify the product design at any stage of the design processes.
This research dealt with cost modelling of both machined components and injection
moulded components.
The developed cost effective design environment was evaluated on real products,
including a scientific calculator, a telephone handset, and two machined components.
Conclusions drawn from the system indicated that the developed prototype system
could help companies reducing product cost and lead time by estimating the total
product cost throughout the entire product development cycle including assembly cost.
Case studies demonstrated that designing a product using the developed system is more
cost effective than using traditional systems. The cost estimated for a number of
products used in the case studies was almost 10 to 15% less than cost estimated by the
traditional system since the latter does not take into consideration process optimisation,
design alternatives, nor design for assembly issue
Aerospace Medicine and Biology: A continuing bibliography, supplement 191
A bibliographical list of 182 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1979 is presented
NASA SBIR abstracts of 1990 phase 1 projects
The research objectives of the 280 projects placed under contract in the National Aeronautics and Space Administration (NASA) 1990 Small Business Innovation Research (SBIR) Phase 1 program are described. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses in response to NASA's 1990 SBIR Phase 1 Program Solicitation. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 280, in order of its appearance in the body of the report. The document also includes Appendixes to provide additional information about the SBIR program and permit cross-reference in the 1990 Phase 1 projects by company name, location by state, principal investigator, NASA field center responsible for management of each project, and NASA contract number
NASA Innovative Advanced Concepts (NIAC) Phase 1 Final Report: Venus Landsailer Zephyr
Imagine sailing across the hot plains of Venus! A design for a craft to do just this was completed by the COncurrent Multidisciplinary Preliminary Assessment of Space Systems (COMPASS) Team for the NASA Innovative Advanced Concepts (NIAC) project. The robotic craft could explore over 30 km of surface of Venus, driven by the power of the wind
Technology 2001: The Second National Technology Transfer Conference and Exposition, volume 2
Proceedings of the workshop are presented. The mission of the conference was to transfer advanced technologies developed by the Federal government, its contractors, and other high-tech organizations to U.S. industries for their use in developing new or improved products and processes. Volume two presents papers on the following topics: materials science, robotics, test and measurement, advanced manufacturing, artificial intelligence, biotechnology, electronics, and software engineering
Development of Advanced Verification and Validation Procedures and Tools for the Certification of Learning Systems in Aerospace Applications
Adaptive control technologies that incorporate learning algorithms have been proposed to enable automatic flight control and vehicle recovery, autonomous flight, and to maintain vehicle performance in the face of unknown, changing, or poorly defined operating environments. In order for adaptive control systems to be used in safety-critical aerospace applications, they must be proven to be highly safe and reliable. Rigorous methods for adaptive software verification and validation must be developed to ensure that control system software failures will not occur. Of central importance in this regard is the need to establish reliable methods that guarantee convergent learning, rapid convergence (learning) rate, and algorithm stability. This paper presents the major problems of adaptive control systems that use learning to improve performance. The paper then presents the major procedures and tools presently developed or currently being developed to enable the verification, validation, and ultimate certification of these adaptive control systems. These technologies include the application of automated program analysis methods, techniques to improve the learning process, analytical methods to verify stability, methods to automatically synthesize code, simulation and test methods, and tools to provide on-line software assurance
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