152 research outputs found

    Microprocessor-Based Systems Control for the Rigidized Inflatable Get-Away-Special Experiment

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    As the demand for space based communications and faster data throughput increase, satellites are becoming larger. Larger satellite antennas help to provide the needed gain to increase communications in space. Compounding the performance and size trade-offs are the payload weight and size limit imposed by the launch vehicles. Inflatable structures offer a cost saving opportunity since the structure is significantly lighter and has a reduced storage volume. This allows for smaller launch vehicles and for increased performance capabilities. Inflatable structures offer possibilities for increased satellite lifetimes, increased communications capacity, and reduce launch costs. This thesis develops and implements the computer control system and power system to support the Rigidized Inflatable Get-Away-Experiment. The autonomous computer system controls the flow of the experiment while at the same time collecting and recording temperature, pressure, vibration, and image data. The computer system consists of two processors, one for experiment control and sensor data collection and the second for image data collection. These two systems can work simultaneously to control the flow of the experiment and meet the experiment objectives. Examples of the data collection include heating curves, pressure, tube transfer function plots and images. This thesis also develops the MatlabĀ® tools required to analyze the data collected by the computers for post-flight data processing. This thesis lays the groundwork for a microprocessor-based architecture for autonomous space experiments. This pioneering effort has been selected for flight testing on-board the U.S. Space Shuttle

    Design and implementation of flexible microprocessor control for retrofitting to first generation robotic devices

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    This Master of Science project concerns the design and development of a flexible microprocessor-based controller for a Versatran Industrial Robot. The software and hardware are designed in modules to enhance the flexibility of the controller so that it can be used as the control unit for other forms of workhandling equipment. The hardware of the designed controller is based on the Texas Instruments single board computer and interface printed circuit boards although some specially designed interface hardware was required. The software is developed in two major categories, which are "real-time" modules and "operator communication" modules. The real-time modules were for the control of the hydraulic servo-valves, pneumatic actuators and interlock switches, whilst the operator communication modules were used to assist the operator in programming "handling" sequences". The main advantages of the controller in its present form can be summarised thus:- (i) The down-time between program changes is significantly reduced; (ii) There can be many more positions programmed in a "handling sequence"; (iii)Greater control over axis dynamics can be achieved The software and hardware structure adopted has sufficient flexibility to allow many future enhancements to be provided. For example, as part of a subsequent research project additional facilities are being implemented as follows: a teach hand held pendant is being installed to improve still further the ease with which "handling sequences" can be programmed; improved control algorithms are being implemented and these will facilitate contouring; communication software is being included so that the controller can access via a node a commercially available local area network

    Compilation and Code Optimization for Data Analytics

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    The trade-offs between the use of modern high-level and low-level programming languages in constructing complex software artifacts are well known. High-level languages allow for greater programmer productivity: abstraction and genericity allow for the same functionality to be implemented with significantly less code compared to low-level languages. Modularity, object-orientation, functional programming, and powerful type systems allow programmers not only to create clean abstractions and protect them from leaking, but also to define code units that are reusable and easily composable, and software architectures that are adaptable and extensible. The abstraction, succinctness, and modularity of high-level code help to avoid software bugs and facilitate debugging and maintenance. The use of high-level languages comes at a performance cost: increased indirection due to abstraction, virtualization, and interpretation, and superfluous work, particularly in the form of tempory memory allocation and deallocation to support objects and encapsulation. As a result of this, the cost of high-level languages for performance-critical systems may seem prohibitive. The vision of abstraction without regret argues that it is possible to use high-level languages for building performance-critical systems that allow for both productivity and high performance, instead of trading off the former for the latter. In this thesis, we realize this vision for building different types of data analytics systems. Our means of achieving this is by employing compilation. The goal is to compile away expensive language features -- to compile high-level code down to efficient low-level code

    Compilation and Code Optimization for Data Analytics

    Get PDF
    The trade-offs between the use of modern high-level and low-level programming languages in constructing complex software artifacts are well known. High-level languages allow for greater programmer productivity: abstraction and genericity allow for the same functionality to be implemented with significantly less code compared to low-level languages. Modularity, object-orientation, functional programming, and powerful type systems allow programmers not only to create clean abstractions and protect them from leaking, but also to define code units that are reusable and easily composable, and software architectures that are adaptable and extensible. The abstraction, succinctness, and modularity of high-level code help to avoid software bugs and facilitate debugging and maintenance. The use of high-level languages comes at a performance cost: increased indirection due to abstraction, virtualization, and interpretation, and superfluous work, particularly in the form of tempory memory allocation and deallocation to support objects and encapsulation. As a result of this, the cost of high-level languages for performance-critical systems may seem prohibitive. The vision of abstraction without regret argues that it is possible to use high-level languages for building performance-critical systems that allow for both productivity and high performance, instead of trading off the former for the latter. In this thesis, we realize this vision for building different types of data analytics systems. Our means of achieving this is by employing compilation. The goal is to compile away expensive language features -- to compile high-level code down to efficient low-level code

    A Pattern-based Foundation for Language-Driven Software Engineering

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    This work brings together two fundamental ideas for modelling, programming and analysing software systems. The first idea is of a methodological nature: engineering software by systematically creating and relating languages. The second idea is of a technical nature: using patterns as a practical foundation for computing. The goal is to show that the systematic creation and layering of languages can be reduced to the elementary operations of pattern matching and instantiation and that this pattern-based approach provides a formal and practical foundation for language-driven modelling, programming and analysis. The underpinning of the work is a novel formalism for recognising, deconstructing, creating, searching, transforming and generally manipulating data structures. The formalism is based on typed sequences, a generic structure for representing trees. It defines basic pattern expressions for matching and instantiating atomic values and variables. Horizontal, vertical, diagonal and hierarchical operators are different ways of combining patterns. Transformations combine matching and instantiating patterns and they are patterns themselves. A quasiquotation mechanism allows arbitrary levels of meta-pattern functionality and forms the basis of pattern abstraction. Path polymorphic operators are used to specify fine-grained search of structures. A range of core concepts such as layering, parsing and pattern-based computing can naturally be defined through pattern expressions. Three language-driven tools that utilise the pattern formalism showcase the applicability of the pattern-approach. Concat is a self-sustaining (meta-)programming system in which all computations are expressed by matching and instantiation. This includes parsing, executing and optimising programs. By applying its language engineering tools to its own meta-language, Concat can extend itself from within. XMF (XML Modeling Framework) is a browser-based modelling- and meta-modelling framework that provides flexible means to create and relate modelling languages and to query and validate models. The pattern functionality that makes this possible is partly exposed as a schema language and partly as a JavaScript library. CFR (Channel Filter Rule Language) implements a language-driven approach for layered analysis of communication in complex networked systems. The communication on each layer is visible in the language of an ā€œabstract protocolā€ that is defined by communication patterns

    NASA Tech Briefs, March 1992

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    Topics include: New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences

    Force sensing enhancement of robot system

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    At present there is a general industrial need to improve robot performance. Force feedback, which involves sensing and actuation, is one means of improving the relative position between the workpiece and the end-effector. In this research work various causes of errors and poor robot performance are identified. Several methods of improving the performance of robotic systems are discussed. As a result of this research, a system was developed which is interposed between the wrist and the gripper of the manipulator. This system integrates a force sensor with a micro-manipulator, via an electronic control unit, with a micro-computer to enhance a robot system. The force sensor, the micromanipulator and the electronic control unit, were all designed and manufactured at the robotic centre of Middlesex Polytechnic. The force feedback is provided by means of strain gauges and the associated bridge circuitry. Control algorithms which define the relationship between the force detected and the motion required are implemented in the software. The software is capable of performing two specific tasks in real time, these are: 1- Inserting a peg into a hole 2- Following an unknown geometric path A rig was designed and manufactured to enable the robot to follow different geometric shapes and paths in which force control was achieved mainly by control of the micro-manipulator

    Benchmarking VisualStudio.NET for the development and implementation of a manufacturing execution system

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    The focus of this thesis is to show the utility of Microsoft\u27s\u27 .NET framework in developing and implementing a MES system. The manufacturing environment today, more than ever, is working towards achieving better yields, productivity, quality, and customer satisfaction. Companies such as DELL are rapidly outgrowing their competition due to better management of their product lifecycles. The time between receiving a new order to the time the final product is shipped is getting shorter. Historically, business management applications such as Enterprise Resource Planning (ERP) systems and Customer Relationship Management (CRM) systems have been implemented without too much importance given to the operational and shop floor needs. The fact is that these business systems can be successful only when they are properly integrated with real-time data from the shop floor, which is the core of any manufacturing set-up. A Manufacturing Execution System or a MES is this link between the shop floor and the top floor. MESA international defines MES as Systems that deliver information enabling the optimization of production activities from order launch to finished goods Thus, a MES provides the right information to the right people at the right time in a right format, to help them make well-informed decisions. Thus, a necessity for an efficient MES is high capability of integration with the existing systems on the operational level. This is where Microsoft\u27s\u27 VS.NET fits in. Microsoft defines .NET as A set of software technologies for connecting information, people, systems and devices . The vision of .NET is to enable the end user to connect to information from any place at anytime, using any device and in a manner that is independent of the platform on which the service is based. The building block of the .NET framework is the Common Language Runtime or CLR, which is capable of converting data from its original format into a format understandable to .NET and then use that format to interface with its client. This feature that .NET provides holds the key in the context of a MES development and implementation. The aim of this applied research is to design a MES using VS.NET to control the working of a Flexible Manufacturing System (FMS) namely CAMCELL. The architecture used for the MES will then be gauged against an MES implementation done previously using a Siemens\u27 PC-based automation technology and Visual FoxPro. This study will integrate the Siemens\u27 technology with the .NET framework to enhance the resulting MES efficiency. The shop floor details or the real-time data collection will be done using the databases from WinCC and data aggregation and manipulation will be done within the .NET framework. The software architecture used for this study will achieve vertical integration between the CAMCELL ERP layer, the MES layer and the Control layer. The study will demonstrate how the data stored in a high level ERP database can be converted into useful information for the control layer for process control and also how real-time information gathered from the control layer can be filtered into useful information up to the ERP layer to facilitate the decision making process. VS.NET user interface screens will be proposed to support these activities. The performance of the proposed architecture will be compared to that from previous studies, thus benchmarking VS.NET for the implementation of the MES

    Numerical aerodynamic simulation facility feasibility study

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    There were three major issues examined in the feasibility study. First, the ability of the proposed system architecture to support the anticipated workload was evaluated. Second, the throughput of the computational engine (the flow model processor) was studied using real application programs. Third, the availability reliability, and maintainability of the system were modeled. The evaluations were based on the baseline systems. The results show that the implementation of the Numerical Aerodynamic Simulation Facility, in the form considered, would indeed be a feasible project with an acceptable level of risk. The technology required (both hardware and software) either already exists or, in the case of a few parts, is expected to be announced this year. Facets of the work described include the hardware configuration, software, user language, and fault tolerance
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