Institute for Systems Research Technical Reports

Permanent URI for this collectionhttp://hdl.handle.net/1903/4376

This archive contains a collection of reports generated by the faculty and students of the Institute for Systems Research (ISR), a permanent, interdisciplinary research unit in the A. James Clark School of Engineering at the University of Maryland. ISR-based projects are conducted through partnerships with industry and government, bringing together faculty and students from multiple academic departments and colleges across the university.

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1987 - 19886

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End date: 1989Subject: search.filters.subject.Chemical Process Systems

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    The Design and the Testing of a 64-Processor Array
    (1988) Wang, H.; JaJa, J.; ISR
    Array architectures based on the VLSI technology allow the processing speed to increase by several orders of magnitude. While VLSI holds the promise of high parallelism by offering almost unlimited hardware at very low cost, there are several inherent constraints with respect to communication, design complexity, testability, etc. In this paper, we are concerned with design and testing of such an architecture. An array- processor chip consisting of 8x8 processing elements (PEs) each with 512 bits of memory was fully designed and fabricated using 2m CMOS technology. One of the novel features of this design is the capability to load data fast into all the PEs simultaneously. Extensive simulations were carried out on this design. This general purpose parallel processor chip was tested using the test workstation IMS-VS2000. An application board was also built by using the Macintosh II as the host controller.
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    Structured Singular Value and m-Form Numerical Range
    (1988) Wang, J.C.; Fan, M.K.H.; ISR
    Although the question of the numerical evaluation of Doyle's structured singular value has been repeatedly addressed, it is not yet entirely resolved in the general case. It has been shown recently that this question can be reduced to that of iteratively computing the distance from the origin to the m-form numerical range of m tuples of matrices. How to effectively compute such distance in the nonconvex case (which may arise when dealing with m more than 3) is an open problem. In this thesis, in an attempt to tackle this problem, the question of graphically displaying 2- dimensional and 3-dimensional sections of the m-form numerical range is investigated.
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    Analysis of Laser Induced Fluorescence Spectra
    (1988) Rinaudo, P.J.B.; Wang, N.S.; ISR
    Abstract's technical formulas were not compatible with the database used to create this booklet. To obtain a copy, please contact Maggie Virkus at (301) 454-6167, maggie@ra.src.umd.edu or write at to the Center's address listed in the front of this booklet.
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    Knowledge Representation for Expert Systems in Chemical Process Control Design
    (1988) Birky, Gregory J.; McAvoy, T.; ISR
    Recognizing the importance to combine the manufacturing system and the management system for machining operation planning, a new methodology is proposed in this paper to evaluate the economic aspect of an operation plan. To assure the quality of a machined part satisfying the required specifications, the manufacturing system acts as an alternative generator to provide meaningful and practical plans. Through costing analysis, the variable, fixed, and total costs associated with the machining operation are quantitatively determined. The management system, which functions as an evaluative mechanism, selects the optimal plan based on the defined goal. This proposed methodology has been used as a framework in designing an expert system. The system establishes the sequence of machining operation planning and search the optimal plan which integrates the considerations from both production engineers and managers, and balances their needs for a quality and productive operation.
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    On-Line Optimization of Chemical Plants Using Steady State Models
    (1988) Koninckx, Jan; McAvoy, T.; ISR
    The subject of this dissertation is the on-line optimization of continuous chemical plants that are operated under steady state. For these plants, transient periods are short compared to periods of steady operation, and a steady state of optimization (using a steady state nonlinear model) covers the major part of the potential gain that can be made through optimization. Cheaper computer technology and a more competitive market cause an increased industrial interest in this supervisory control technique. The existing literature on applications of on-line optimization using steady state models is discussed. Publications reflect the wide interest in the optimization based technique, but in general the reports are vague, and they do not answer many fundamental questions. Some are even contradictory on isssues such as partitioning of the optimization problem or choice of optimization variables. In this dissertation, a modular structure for an on-line optimizer is suggested. In this structure, existing algorithms in model updating, data reconciliation and optimization are combined with new applications. The application of sensitivity analysis is the most important new approach that is presented in this dissertation. Optimization sensitivity analysis is a computationally cheap tool that provides information about the status of an optimization result. That information can be used in an on-line optimizer for use in a significance test of setpoint changes, and for an on-line accuracy assessment of the on-line optimizer operation. Sensitivity information is therefore combined with statistical information from e.g. the model updating module. Results from a sensitivity analysis can also be used in short-cut feasibility studies. Also model execution frequency, data reconciliation techniques and particular problems with model updating are discussed, as well as the influence of noise on the performance of on-line optimized plants. Case study results are provided as illustration. The systems studied in these case studies are a distillation column (propane propylene splitter), a boiler network with common header and a simple heat exchanger network.
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    Control System Design for a Flexible Arm
    (1987) Wang, L.S.; Krishnaprasad, P.S.; ISR
    In this thesis, we study the problem of real-time control of a flexible arm. We have investigated techniques for compensating the effects of friction and ripple torque. New software was written to use a Metrabyte Data Acquisition and Control board for the real time implementation. A controller-observer scheme was used together with integral feedback. In the design of feedback gains, a newly developed package called CONSOLE was used. After translating the continuous-time design to the discrete-system and before implementation, a package called SIMNON was used to do the simulation of the whole system and to explore the effect of different sampling rates. The experiments done so far imply that the schemes used here are sound for real-time control of flexible structures.