Spent nuclear fuel project multi-canister overpack, additional NRC requirements (open access)

Spent nuclear fuel project multi-canister overpack, additional NRC requirements

The US Department of Energy (DOE), established in the K Basin Spent Nuclear Fuel Project Regulatory Policy, dated August 4, 1995 (hereafter referred to as the Policy), the requirement for new Spent Nuclear Fuel (SNF) Project facilities to achieve nuclear safety equivalency to comparable US Nuclear Regulatory Commission (NRC)-licensed facilities. For activities other than during transport, when the Multi-Canister Overpack (MCO) is used and resides in the Canister Storage Building (CSB), Cold Vacuum Drying (CVD) facility or Hot Conditioning System, additional NRC requirements will also apply to the MCO based on the safety functions it performs and its interfaces with the SNF Project facilities. An evaluation was performed in consideration of the MCO safety functions to identify any additional NRC requirements needed, in combination with the existing and applicable DOE requirements, to establish nuclear safety equivalency for the MCO. The background, basic safety issues and general comparison of NRC and DOE requirements for the SNF Project are presented in WHC-SD-SNF-DB-002.
Date: August 4, 1998
Creator: Garvin, L. J.
Object Type: Report
System: The UNT Digital Library
LLCEDATA and LLCECALC for Windows version 1.0, Volume 2: Technical manual (open access)

LLCEDATA and LLCECALC for Windows version 1.0, Volume 2: Technical manual

LLCEDATA and LLCECALC for Windows are user-friendly computer software programs that work together to determine the proper waste designation, handling, and disposition requirements for Long Length Contaminated Equipment (LLCE). LLCEDATA reads from a variety of databases to produce an equipment data file (EDF) that represents a snapshot of both the LLCE and the tank from which it originates. LLCECALC reads the EDF and the gamma assay (AV2) file that is produced by the Flexible Receiver Gamma Energy Analysis System. LLCECALC performs corrections to the AV2 file as it is being read and characterizes the LLCE Both programs produce a variety of reports, including a characterization report and a status report. The status report documents each action taken by the user, LLCEDA TA, and LLCECALC. Documentation for LLCEDA TA and LLCECALC for Windows is available in three volumes. Volume 1 is a user`s manual, which is intended as a quick reference for both LLCEDATA and LLCECALC. Volume 2 is a technical manual, which documents LLCEDATA and LLCECALCs methodology, structure, and format, provides sample calculations; discusses system limitations; and provides recommendations to the LLCE process. Volume 3 is a software verification and validation document LLCEDATA and LLCECALC for Windows are sponsored by …
Date: September 4, 1998
Creator: McFadden, J. G.
Object Type: Report
System: The UNT Digital Library
SRS control system upgrade requirements (open access)

SRS control system upgrade requirements

This document defines requirements for an upgrade of the Sodium Removal System (SRS) control system. The upgrade is being performed to solve a number of maintainability and operability issues. The upgraded system will provide the same functions, controls and interlocks as the present system, and in addition provide enhanced functionality in areas discussed in this document.
Date: August 4, 1998
Creator: Hill, L. F.
Object Type: Report
System: The UNT Digital Library
LLCEDATA and LLCECALC for Windows version 1.0, Volume 3: Software verification and validation (open access)

LLCEDATA and LLCECALC for Windows version 1.0, Volume 3: Software verification and validation

LLCEDATA and LLCECALC for Windows are user-friendly computer software programs that work together to determine the proper waste designation, handling, and disposition requirements for Long Length Contaminated Equipment (LLCE). LLCEDATA reads from a variety of data bases to produce an equipment data file(EDF) that represents a snapshot of both the LLCE and the tank from which it originates. LLCECALC reads the EDF and the gamma assay file (AV2) that is produced by the flexible Receiver Gamma Energy Analysis System. LLCECALC performs corrections to the AV2 file as it is being read and characterizes the LLCE. Both programs produce a variety of reports, including a characterization report and a status report. The status report documents each action taken by the user, LLCEDATA, and LLCECALC. Documentation for LLCEDATA and LLCECALC for Windows is available in three volumes. Volume 1 is a user`s manual, which is intended as a quick reference for both LLCEDATA and LLCECALC. Volume 2 is a technical manual, which discusses system limitations and provides recommendations to the LLCE process. Volume 3 documents LLCEDATA and LLCECALC`s verification and validation. Two of the three installation test cases, from Volume 1, are independently confirmed. Data bases used in LLCEDATA are verified and …
Date: September 4, 1998
Creator: McFadden, J. G.
Object Type: Report
System: The UNT Digital Library
Test plan for Tank 241-AW-101 solubility screening tests (open access)

Test plan for Tank 241-AW-101 solubility screening tests

Tank 241-AW-101 (101-AW) has been identified as one of the early tanks to be for retrieved for low level waste pretreatment and immobilization and retrieval of the tank waste may require dilution. This test is to determine the effects of dilution on the mass of solids and their composition. This test plan gives test instructions, example data sheets, a waste compatibility review, and a waste stream fact sheet. This test Plan is similar to tests on tanks 241-AN-102 (Person 1998a) and 241-AN-107 (Person 1998 b). The 101-AW tests will be done with composites of liquid and solids from grab samples that were taken in 1998 (Benar 1998). Future revisions of the Tank Sampling and Analysis Plan (Benar 1998) may change the details of the work performed under this test plan.
Date: August 4, 1998
Creator: Person, J. C.
Object Type: Report
System: The UNT Digital Library
Polychlorinated biphenyls (PCB) analysis report for solid sample from 219S tank 101 (open access)

Polychlorinated biphenyls (PCB) analysis report for solid sample from 219S tank 101

One waste sample that was obtained with solids from tank 101 of 219S via a peristaltic pump equipped with a stainless steel tube and Norprene tubing (Phthalate free) was obtained in a glass jar with teflon lid was analyzed (with duplicate, matrix spike, and matrix spike duplicate) for PCBs as Aroclor mixtures by the Inorganic/Organic Chemistry Group. A soxhlet extraction procedure was used for extraction of the Aroclors from the sample. Analysis was performed using dual column confirmation gas chromatography/electron capture detection (GC/ECD). Results are presented.
Date: February 4, 1998
Creator: Diaz, L. A.
Object Type: Report
System: The UNT Digital Library
LLCEDATA and LLCECALC for Windows version 1.0, Volume 1: User`s manual (open access)

LLCEDATA and LLCECALC for Windows version 1.0, Volume 1: User`s manual

LLCEDATA and LLCECALC for Windows are user-friendly computer software programs that work together to determine the proper waste designation, handling, and disposition requirements for Long Length Contaminated Equipment (LLCE). LLCEDATA reads from a variety of data bases to produce an equipment data file (EDF) that represents a snapshot of both the LLCE and the tank it originates from. LLCECALC reads the EDF and a gamma assay (AV2) file that is produced by the Flexible Receiver Gamma Energy Analysis System. LLCECALC performs corrections to the AV2 file as it is being read and characterizes the LLCE. Both programs produce a variety of reports, including a characterization report and a status report. The status report documents each action taken by the user, LLCEDATA, and LLCECALC. Documentation for LLCEDATA and LLCECALC for Windows is available in three volumes. Volume 1 is a user`s manual, which is intended as a quick reference for both LLCEDATA and LLCECALC. Volume 2 is a technical manual, and Volume 3 is a software verification and validation document.
Date: September 4, 1998
Creator: McFadden, J. G.
Object Type: Report
System: The UNT Digital Library
Physics of Polarity at RHIC-Volume 10 (open access)

Physics of Polarity at RHIC-Volume 10

The RBRC Workshop on Physics of Polarimetry at RHIC was held from Aug 4 to 7, 1998 at BNL. The primary motive of the workshop is (1) to discuss the RHIC polarimeter using the elastic proton-carbon scattering at Coulomb-nuclear interference region (p-C CNI polarimeter) in detail and write a proposal for the test experiment a t the AGS, (2) to discuss the related physics, (3) and to discuss other options for the RHIC polarimetry. The idea of the p-C CNI polarimeter was proposed last year as a simple, inexpensive and efficient polarimeter for RHIC. In order to establish this polarimeter, we have decided to carry out a test experiment by using a polarized beam at the AGS. We have made a draft of the proposal during the workshop. For the p-C CNI polarimeter, a telescope detector using both the micro-channel plate (MCP) and the SSD was proposed to detect low energy recoil carbon ions, based on the test measurements at IUCF and Kyoto, where the carbon ions as low as 200 keV were successfully detected. The kinetic energy of carbon ion is measured with the SSD, and the velocity is measured by TOF between the two detectors and between the …
Date: August 4, 1998
Creator: Imai, K. & Fields, D.
Object Type: Article
System: The UNT Digital Library
Integrated computer control system startup simulation (open access)

Integrated computer control system startup simulation

A simulation of the startup time for the ICCS (Integrated Computer Control System ) applied to the National Ignition Facility (NIF) has been performed. The simulation results provide confidence that this requirement can be met. This document describes the results of the simulation that was done using the SIMPROCESS discrete-event-modeling tool. The requirement for start up time established for the NIF control system is: Restarting all computers from a power-down condition shall take less than 30 minutes. This allows quick recovery from a power failure.
Date: February 4, 1998
Creator: Kettering, B & Van Arsdall, P
Object Type: Report
System: The UNT Digital Library
Measurements at 351 nm of temporal dispersion in fibers (open access)

Measurements at 351 nm of temporal dispersion in fibers

1. Temporal dispersion at 351-nm was measured in the following: a 35-m bundle of 19 each 50-µm-core fibers, a companion 35-m single fiber, a 100-µm-core single fiber (at 4 lengths), and a 50-µm-core single fiber (two samples, 7 lengths). The 50-µm-core fiber was from preform #24; the 100-µm-core fiber was a prototype version having a thick cladding. All of the fibers were developed and manufactured at the Vavilov State Optical Institute, St. Petersburg, Russia. 2. Dispersion measurements were made by propagating a 20-ps 351-nm pulse through the fiber under test and recording the output on an S20 streak camera. The width of the pulse transmitted by the fiber was compared to that of a fraction of the pulse that had propagated over an air path. Values of dispersion were calculated as, D = {radical}(F² - A²) , where F and A are the full widths at half maximum (FWHM) for, respectively, the fiber-path and the air-path streaks. 3. In each of the experiments, the measured dispersion increased with counts in the streak record, which in principle, are proportional to intensity in the fiber. Measured values of dispersion ranged from about 0.6 to 1.0 ps/m for the single fibers. 4. The …
Date: November 4, 1998
Creator: Griffith, R; Milam, D; Sell, W & Thompson, C
Object Type: Report
System: The UNT Digital Library
Microstructural examination of irradiated V-(4-5%)Cr-(4-5%)Ti. (open access)

Microstructural examination of irradiated V-(4-5%)Cr-(4-5%)Ti.

Microstructural examination results are reported for two heats of V-(4-5%) Cr-(4-5%)Ti irradiated in the EBR-II X530 experiment to 4.5 dpa at {approximately}400 C to provide an understanding of the microstructural evolution that may be associated with degradation of mechanical properties. Fine precipitates were observed in high density intermixed with small defect clusters for all conditions examined following the irradiation. The irradiation-induced precipitation does not appear to be affected by preirradiation heat treatment at 950-1125 C. There was no evidence for a significant density of large (diameter >10 nm) dislocation loops or network dislocations. Analytical investigations successfully demonstrated that the precipitates were enriched in titanium, depleted in vanadium and contained no nitrogen. These results are discussed in terms of future alloy development options.
Date: May 4, 1998
Creator: Gelles, D. S.
Object Type: Article
System: The UNT Digital Library
Cellular Manufacturing Internet Performance Support System (open access)

Cellular Manufacturing Internet Performance Support System

The objective of this project was to develop an Internet-based electronic performance support system (EPSS) for cellular manufacturing providing hardware/software specifications, process descriptions, estimated cost savings, manufacturing simulations, training information, and service resources for government and industry users of Cincinnati Milacron machine tools and products. AlliedSignal Federal Manufacturing and Technologies (ASFM and T) used expertise in the areas of Internet design and multimedia creation to develop a performance support system (PSS) for the Internet with assistance from CM's subject matter experts from engineering, manufacturing, and technical support. Reference information was both created and re-purposed from other existing formats, then made available on the Internet. On-line references on cellular manufacturing operations include: definitions of cells and cellular manufacturing; illustrations on how cellular manufacturing improves part throughput, resource utilization, part quality, and manufacturing flexibility; illustrations on how cellular manufacturing reduces labor and overhead costs; identification of critical factors driving decisions toward cellular manufacturing; a method for identifying process improvement areas using cellular manufacturing; a method for customizing the size of cells for a specific site; a simulation for making a part using cellular manufacturing technology; and a glossary of terms and concepts.
Date: March 4, 1998
Creator: Bohley, M.C. & Schwartz, M.E.
Object Type: Report
System: The UNT Digital Library
Solving QCD via multi-Regge theory. (open access)

Solving QCD via multi-Regge theory.

A high-energy, transverse momentum cut-off, solution of QCD is outlined. Regge pole and single gluon properties of the pomeron are directly related to the confinement and chiral symmetry breaking properties of the hadron spectrum. This solution, which corresponds to a supercritical phase of Reggeon Field Theory, may only be applicable to QCD with a very special quark content.
Date: November 4, 1998
Creator: White, A. R.
Object Type: Article
System: The UNT Digital Library
Inductively Coupled Plasma Etching of III-V Antimonides in BCl(3)/Ar and Cl(2)/Ar (open access)

Inductively Coupled Plasma Etching of III-V Antimonides in BCl(3)/Ar and Cl(2)/Ar

Inductively coupled plasma (ICP) etching characteristics of GaSb and AIGaAsSb have been investigated in BC13/Ar and Clz/Ar plasmas. The etch rates and selectivity between GaSb and AIGaAsSb are reported as functions of plasma chemistry, ICP power, RF self-bias, and chamber pressure. It is found that physical sputtering resorption of the etch products plays a dominant role in BC13/Ar ICP etching, while in Clz/Ar plasma, the chemical reaction dominates the etching. GaSb etch rates exceeding 2 ~rnhnin are achieved in Clz/Ar plasmas with smooth surfaces and anisotropic profiles. In BC13/Ar plasmas, etch rates of 5100 Mmin and 4200 Mmin are obtained for GaSb and AIGaAsSb, respectively. The surfaces of both GaSb and AIGaAsSb etched in BC13/Ar plasmas remain smooth and stoichiometric over the entire range of plasma conditions investigated. This result is attributed to effective removal of etch products by physical sputtering. For a wide range of plasma conditions, the selectivity between GaSb and AIGaAsSb is close to unity, which is desirable for fabricating etched mirrors and gratings for Sb-based mid-IR laser diodes.
Date: November 4, 1998
Creator: Leavitt, R.P.; Lester, L.F.; Shul, R.J.; Willison, C.G. & Zhang, L.
Object Type: Article
System: The UNT Digital Library
Linac Coherent Light Source (LCLS) Design Study Report (open access)

Linac Coherent Light Source (LCLS) Design Study Report

The Stanford Linear Accelerator Center, in collaboration with Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and the University of California at Los Angeles, is proposing to build a Free-Electron-Laser (FEL) R and D facility operating in the wavelength range 1.5-15 {angstrom}. This FEL, called the ''Linac Coherent Light Source'' (LCLS), utilizes the SLAC linac and produces sub-picosecond pulses of short wavelength x-rays with very high peak brightness and full transverse coherence. Starting in FY 1998, the first two-thirds of the SLAC linac will be used for injection into the B factory. This leaves the last one-third free for acceleration to 15 GeV. The LCLS takes advantage of this opportunity, opening the way for the next generation of synchrotron light sources with largely proven technology and cost effective methods. This proposal is consistent with the recommendations of the Report of the Basic Energy Sciences Advisory Committee (Synchrotron Radiation Light Source Working Group, October 18-19, 1997). The report recognizes that ''fourth-generation x-ray sources...will in all likelihood be based on the free electron laser concepts. If successful, this technology could yield improvements in brightness by many orders of magnitude.'' This Design Study, the authors believe, confirms the feasibility of constructing an x-ray …
Date: December 4, 1998
Creator: Cornacchia, Massimo
Object Type: Report
System: The UNT Digital Library
The Production and Acceleration of Radioactive Ion Beams at the HRIBF (open access)

The Production and Acceleration of Radioactive Ion Beams at the HRIBF

The Holifield Radioactive Ion Beam Facility (HRIBF) includes a cyclotron (ORIC) which provides high-intensity light-ions for producing radioactive atoms, and a 25 MV tandem electrostatic accelerator which is used to accelerate the radioactive-ions for nuclear structure and nuclear astrophysics research. Ion sources and targets suitable for the production of various radioactive ion beams (RIBs) have been developed. Operational experiences, problem areas, and plans for future beam development are discussed.
Date: November 4, 1998
Creator: Auble, R. L.
Object Type: Article
System: The UNT Digital Library
Advances in fabrication of Ag-clad Bi-2223 superconductors. (open access)

Advances in fabrication of Ag-clad Bi-2223 superconductors.

Powder-in-tube (PIT) processing was used to fabricate multifilamentary Ag-clad Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub y} (Bi-2223) superconductors for various electric power applications. Enhancements in the transport current properties of long lengths of multifilament tapes were achieved by increasing the packing density of the precursor powder, improving the mechanical deformation, and adjusting the cooling rate. The dependence of the critical current density on magnetic field and temperature for the optimally processed tapes was measured. J{sub c} was greater than 10{sup 4} (A/cm{sup 2}) at 20 K for magnetic field up to 3 T and parallel to the c-axis which is of interest for use in refrigerator coded magnets. An attempt was made to combine the good alignment of Bi-2223 grains in Ag-sheathed superconducting tapes to obtain high J{sub c} values at high temperature and low field, and good intrinsic pinning of YBa{sub 2}Cu{sub 3}O{sub 7{minus}d} (Y-123) thin film to maintain high J{sub c} values in high fields. A new composite multifilament tape was fabricated such that the central part contained Bi-2223 filaments, with the primary function of conducting the transport current. The central Bi-2223 filaments were surrounded by Y-123 thin film to shield the applied magnetic field and protect the Bi-2223 …
Date: September 4, 1998
Creator: Balachandran, U.
Object Type: Article
System: The UNT Digital Library
Lithium-endohedral C{sub 60} complexes. (open access)

Lithium-endohedral C{sub 60} complexes.

High capacity, reversible, lithium intercalated carbon anodes have been prepared, 855 m.Ah/g, which exceed the capacity for stage 1 lithium intercalated carbon anodes, 372 mAh/g. Since there is very little hydrogen content in the high capacity anode, the fullerene C{sub 60} lattice is used to investigate the nature of lithium ion bonding and spacing between lithiums in endohedral lithium complexes of C{sub 60}. Three lithium-endohedral complexes have been investigated using ab initio molecular orbital calculations involving 2,3 and 5 lithium. The calculated results suggest that lithium cluster formation may be important for achieving the high capacity lithium carbon anodes.
Date: May 4, 1998
Creator: Scanlon, L. G.
Object Type: Article
System: The UNT Digital Library
Statistical Tests of System Linearity Based on the Method of Surrogate Data (open access)

Statistical Tests of System Linearity Based on the Method of Surrogate Data

When dealing with measured data from dynamic systems we often make the tacit assumption that the data are generated by linear dynamics. While some systematic tests for linearity and determinism are available - for example the coherence fimction, the probability density fimction, and the bispectrum - fi,u-ther tests that quanti$ the existence and the degree of nonlinearity are clearly needed. In this paper we demonstrate a statistical test for the nonlinearity exhibited by a dynamic system excited by Gaussian random noise. We perform the usual division of the input and response time series data into blocks as required by the Welch method of spectrum estimation and search for significant relationships between a given input fkequency and response at harmonics of the selected input frequency. We argue that systematic tests based on the recently developed statistical method of surrogate data readily detect significant nonlinear relationships. The paper elucidates the method of surrogate data. Typical results are illustrated for a linear single degree-of-freedom system and for a system with polynomial stiffness nonlinearity.
Date: November 4, 1998
Creator: Hunter, N.; Paez, T. & Red-Horse, J.
Object Type: Article
System: The UNT Digital Library
EPR detection of light-generated nuclear coherences in photosynthetic reaction centers. (open access)

EPR detection of light-generated nuclear coherences in photosynthetic reaction centers.

In this study we first discuss a pulsed EPR experiment designed to establish the mechanism of coherence generation [1]. The pulse sequence employed, flash-t-({pi}/2){sub x}-{tau}, consists of a short laser pulse at time zero, followed by a variable period t. At the end of this period a non-ideal ({pi}/2) microwave pulse is applied. The resulting free-induction decay at fixed detection time {tau} is then monitored as a function of successively incremented values of t. For P{sub 700}{sup +} A{sub 1}{sup {minus}} in deuterated and {sup 15}N-substituted PSI preparations, the transverse magnetization shows an oscillatory dependence on the delay between the laser and the microwave pulse [1]. Apparently, there are fast initial oscillations which disappear 250 ns after the laser pulse. In addition, slow persisting oscillations with frequencies of a few MHz can be observed. Basically, these slow oscillations represent nuclear coherences initiated by the laser pulse [1].
Date: May 4, 1998
Creator: Bechtold, M.
Object Type: Article
System: The UNT Digital Library
Chemically Selective Coated Quartz Crystal Microbalance (QCM) Array for Detection of Volatile Organic Chemicals (open access)

Chemically Selective Coated Quartz Crystal Microbalance (QCM) Array for Detection of Volatile Organic Chemicals

Liquid flow cells have been fabricated to prepare an array of QCMS operating simultaneously for detection and identification of VOCS in water. TWO signals, a tlequency response and a damping voltage response, were obtained per resonator. A blank QCM was used as a reference to account for changes in liquid density and viscosity. Nine different polymer coatings applied using a spin coat technique have been examined for VOC response under liquid flow conditions. A matrix of three classes of VOCS were examined for each coating with four chemicals in each class. The three classes of VOCS are polar, nonpolar and chlorinated. A pattern recognition technique, called visually empirical region of influence (VERI), was used to cluster the responses in n-dimensional space. Chemicals within a class varying by only one methyl group (e.g., toluene and xylene) are easily discriminated using only two different coatings with three different QCM responses. All chemicak were easily separated and detected with a total of 5 films and 6 responses with >99% accuracy.
Date: November 4, 1998
Creator: Bohuszewicz, T. V.; Frye-Mason, G. C.; Martin, S. J.; Osbourn, G. C.; Schneider, T. W. & Spates, J. J.
Object Type: Article
System: The UNT Digital Library
Characterization of spent EBR-II driver fuel. (open access)

Characterization of spent EBR-II driver fuel.

Operations and material control and accountancy requirements for the Fuel Conditioning Facility demand accurate prediction of the mass flow of spent EBR-II driver fuel into the facility. This requires validated calculational tools that can predict the burnup and isotopic distribution in irradiated Zr-alloy fueled driver assemblies. Detailed core-follow depletion calculations have been performed for an extensive series of EBR-II runs to produce a database of material inventories for the spent fuel to be processed. As this fuel is processed, comparison of calculated values with measured data obtained from samples of this fuel is producing a growing set of validation data. A more extensive set of samples and measurements from the initial processing of irradiated driver fuel has produced valuable estimates of the biases and uncertainties in both the measured and calculated values. Results of these comparisons are presented herein and indicate the calculated values adequately predict the mass flows.
Date: May 4, 1998
Creator: McKnight, R. D.
Object Type: Article
System: The UNT Digital Library
A Methodology to Validate 3-D Arbitrary Lagrangian Eulerian Codes with Applications to Alegra (open access)

A Methodology to Validate 3-D Arbitrary Lagrangian Eulerian Codes with Applications to Alegra

In this study we provided an experimental test bed for validating features of the Arbitrary Lagrangian Eulerian Grid for Research Applications (ALEGRA) code over a broad range of strain rates with overlapping diagnostics that encompass the multiple responses. A unique feature of the ALEGRA code is that it allows simultaneous computational treatment, within one code, of a wide range of strain-rates varying from hydrodynamic to structural conditions. This range encompasses strain rates characteristic of shock-wave propagation (107/s) and those characteristics of structural response (102/s). Most previous code validation experimental &udies, however, have been restricted to simulating or investigating a single strain-rate regime. What is new and different in this investigation is that we have performed well-controlled and well-instrumented experiments, which capture features relevant to both hydrodynamic and structural response in a single experiment. Aluminum was chosen for use in this study because it is a well-characterized material. The current experiments span strain rate regimes of over 107/s to less than 102/s in a single experiment. The input conditions were extremely well defined. Velocity interferometers were used to record the high' strain-rate response, while low strain rate data were collected using strain gauges. Although the current tests were conducted at a …
Date: November 4, 1998
Creator: Chhabildas, L. C.; Duggins, B. D.; Konrad, C. H.; Mosher, D. A.; Perry, J. S.; Reinhart, W. D. et al.
Object Type: Article
System: The UNT Digital Library
Analysis of Decentralized Variable Structure Control for Collective Search by Mobile Robots (open access)

Analysis of Decentralized Variable Structure Control for Collective Search by Mobile Robots

This paper presents an analysis of a decentralized coordination strategy for organizing and controlling a team of mobile robots performing collective search. The alpha-beta coordination strategy is a family of collective search algorithms that allow teams of communicating robots to implicitly coordinate their search activities through a division of labor based on self-selected roIes. In an alpha-beta team. alpha agents are motivated to improve their status by exploring new regions of the search space. Beta a~ents are conservative, and reiy on the alpha agents to provide advanced information on favorable regions of the search space. An agent selects its current role dynamically based on its current status value relative to the current status values of the other team members. Status is determined by some function of the agent's sensor readings, and is generally a measurement of source intensity at the agent's current location. Variations on the decision rules determining alpha and beta behavior produce different versions of the algorithm that lead to different global properties. The alpha-beta strategy is based on a simple finite-state machine that implements a form of Variable Structure Control (VSC). The VSC system changes the dynamics of the collective system by abruptly switching at defined states …
Date: November 4, 1998
Creator: Feddema, J.; Goldsmith, S. & Robinett, R.
Object Type: Article
System: The UNT Digital Library