1998 - Draper Laboratory

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Ward, Paul A.Patent #5600064 Date Issued: February 4, 1997Electronics for Coriolis force and other sensorsPatent #5604309 Date Issued: February 18, 1997Electronics for Coriolis force and other sensorsPatent #5608351 Date Issued: March 4, 1997Electronics for Coriolis force and other sensorsPatent #5672949 Date Issued: September 30, 1997Electronics for Coriolis force and other sensorsElectronics for use in Coriolis and other sensors for reducing errors in thesensor output signal is disclosed. An off-frequency drive scheme includesa frequency translation circuit in the excitation feedback loop of a sensorsystem to suppress components of the sensor drive signal at apredetermined frequency so that coupling of the drive signal to thesensor output signal can be readily removed by conventional filteringtechniques. An amplifier circuit having a bandpass circuit in cascade withthe forward loop gain is provided, with the bandpass circuit having atransfer function approximating one plus a bandpass characteristic, thepassband of which corresponds to the information band. Thisarrangement increases the open-loop gain of the amplifier circuit aroundthe information frequency without affecting the open-loop gain at DCand crossover so as to reduce phase and gain errors around theinformation frequency. A quadrature nulling system is provided for anin-plane micromechanical gyroscope. A signal having an in-phasecomponent due to Coriolis induced out-of-plane motion and aquadrature component due to mechanical misalignments is mixed with avoltage in-phase with motor position. The mixer output is used to applya DC potential to motor drive electrodes and is automatically adjusted bythe integral compensator until the mixer output is zero, resulting in anulled quadrature component.1997 Patents Issued3
1997 Published PapersThe following pages contain the bibliographical information and a brief abstract of all papersformally published by Draper engineers during the 1997 calendar year.Adams, M.; Kolitz, S.; Milner, J.; Odoni, A.Evolutionary concepts for decentralized air traffic flow managementAir Traffic Control Quarterly, Summer 1997Alternative concepts for modifying the policies and procedures underwhich the air traffic flow management system operates are described, andan approach to the evaluation of those alternative concepts is discussed.Here, air traffic flow management includes all activities related tomanaging the flow of aircraft and related system resources from “block toblock.” The alternative concepts represent stages in the evolution fromthe current system, in which air traffic management decision-making islargely centralized within the Federal Aviation Agency (FAA), to a moredecentralized approach wherein the airlines and other airspace userscollaborate in air traffic management decision making with the FAA.Emphasis in the discussion is on a viable medium-term partiallydecentralized scenario that represents a phase of this evolution that isconsistent with the decision-making approaches embodied in proposed“Free-Flight” concepts for air traffic management. System-level metricsfor analyzing and evaluating the various alternatives are defined, and asimulation testbed developed to generate values for those metrics isdescribed. The fundamental issue of modeling airline behavior indecentralized environments is also raised, and an example of such amodel that deals with preserving flight bank integrity in hub airports ispresented.Adams, M.; Kolitz, S.; Odoni, A.Modeling alternative air traffic flow management conceptsProceedings of the IFAC Meeting, Greece, June 1997This paper describes a range of alternative concepts for the policies andprocedures under which the Air Traffic Flow Management (ATFM)system operates and a set of integrated models needed to examine theircosts and benefits. The concepts represent a multistage evolution fromthe current system to increasingly decentralized approaches to decisionmaking.Agopovich, J. W.PFC alternatives analysisPrecision Cleaning 5, (3), 19-22, 24-26, 28, 30-31 March 1997,ISSN: 1068-6037New classes of solvents that are alternatives to PFCs suitable for cleaningcritical inertial guidance devices, such as gyroscopes and accelerometersthat have complex geometries, are reviewed. Characteristics of solventsfor precision cleaning, physical properties, cost, and criteria forevaluating cleanliness are discussed.Agustin, R. M.; Mangoubi, R. S.; Hain, R. M.; Adams, N. J.Robust thrust estimation for aerospace vehicle reaction control systemsProceedings of the 1997 American Control Conference, 15th,Albuquerque, NM, June 1997This paper considers the problem of estimating the thrust from multiplejets firing from the Reaction Control Systems (RCS) used by reusablelaunch vehicles. The thrust estimates can be used to monitor the healthof the RCS, i.e., detecting jet failures. For accurately known state-spacedynamics, the Kalman filter provides the optimal estimate in theleast-squares sense for the jet thrust. During reentry, however, plantmodel uncertainties are a major problem for the filter as the vehicle’saerodynamics vary widely. Consequently, the Kalman filter estimatedegrades severely. Transient, robust H-infinity or game-theoreticestimators are shown to give promising estimation and detectionperformance results for a wide range of Mach numbers and angles ofattack when tried on a simulation of the Space Shuttle Orbiter’s RCS.Allinger, D. F.; Rosch, G.; Kuchar, J. K.Integrated safety-analysis methodology for emerging air-transport technologiesProceedings of the Annual Reliability and Maintainability Symposium,Anaheim, CA, January 1998We demonstrate an approach to integrating reliability, performance, andoperational procedures modeling into a system safety analysis. Ourmethodology is distinguished by its ability to merge system designinformation with the dynamic parameterization of a system’s situation inorder to measure accident statistics and reliable system operation. As anapplication of this methodology, we have considered the problem ofsimultaneous but independent approaches of two aircraft onclosely-spaced parallel runways, Independent Approaches on ParallelRunways (IAPR). The IAPR concept presumes a flight-deck-basednavigation, communication, surveillance, and alerting system. Thepotential exists for an aircraft on either runway to deviate off coursetoward another aircraft on the parallel runway. A variety of simulationprojects have been undertaken within the last several years to explorealerting systems for the parallel approach situation, but the majorlimitation of statistical information generated from these studies is that itrepresents conditional safety statistics given the flight track simulated. Toremove this conditioning, we have shown how to apply the probabilityof flying the approach with a given flight track using Markov analysis tocompute this probability. The results show how each of the probabilitiesof reliable operation, accidents, and false alarms vary as a function ofrunway spacing.Anderson, J. M.; Triantafyllou, M. S.; Kerrebrock, P. A.Concept design of a flexible-hull unmanned undersea vehicleProceedings of the 1997 7th International Offshoreand Polar Engineering ConferenceIn recent years, research in the propulsion and maneuvering mechanismsused by fish has demonstrated the utility of biopropulsion for use onundersea vehicles. Despite recent advances in Unmanned UnderseaVehicle (UUV) technology, little progress has been made in improvingpropulsive efficiency and maneuverability. Most underwater vehicledesigns employ a conventional propeller as the main propulsor andshrouded thrusters and/or control fins for maneuvering. Two types ofvehicle designs are prevalent: torpedo-shaped bodies streamlined forspeed and range, or box-shaped bodies designed for maneuvering andstation keeping. Unfortunately, most future UUV missions require allthese capabilities: high transit speed, long range/duration,maneuverability, and station keeping ability. Thus, we look to fish as apotentially optimal UUV design in that they are able to cruise greatdistances at significant speed, maneuver in tight spaces, and accelerateand decelerate quickly. This paper summarizes the relevant design issuesand current work in the development of a flexible-hull UUV that propelsand maneuvers like a fish. Following the morphology and kinematics ofa yellowfin tuna, the Charles Stark Draper Laboratory Vorticity ControlUUV (VCUUV) will be the first demonstration of a freely swimmingThunniform (tuna-like motion) robotic vehicle. Simulation of therequired kinematics and loads indicate that Thunniform motion can beactuated with a rigid forebody comprising 60 percent of the total vehiclelength and four rigid links actuating the tail section and caudal fin. Three1997 Published Papers1
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Letter from thePresident and CEO,Vi
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Information TechnologyMilton AdamsE
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BiographyMilton Adams has been at D
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Figure 1 represents a functional de
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Programs. In effect, these controll
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Although the terminal area traffic
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Table 2. ATFM performance evaluatio
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In the experiments, a nominal capac
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[3] Wambsganss, Michael C. “Colla
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Guidance, Navigation, and Control A
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A Control Lyapunov FunctionApproach
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x( 0) ∈ X and w(t) ∈Wfor all t
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(b) Select a quadratic RCLF V i (x)
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at each grid point. In the case w 1
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References[1] Ball, J.A. and A.J. v
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Relative and Differential GPSData T
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The first term on the right in the
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H R# δρ R,GPS -H A# δρ A,GPSThi
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selection; and (3) shown that the a
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Segmentation of MR ImagesUsing Curv
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(3)where ν now represents a contin
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Experimental ResultsThe results of
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Table 1. A summary of segmentation
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Guidance, Navigation,and ControlJim
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BiographyGeorge SchmidtGeorge Schmi
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clock and ephemeris errors, as well
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maintained in a rigid structure, wh
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Table 5. “Typical” absolute GPS
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performed, then the target location
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tightly-coupled system, however, ca
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Concluding RemarksRecent progress i
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As real-time systems evolve into th
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Advanced Fault-TolerantComputing fo
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The Viking and Voyager were both in
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Containment Regions (FCRs). There a
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well as reversing the whole process
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As real-time systems evolve into th
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Automated Station-Keepingfor Satell
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Figure 2. Minimum elevation angles
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anomaly M and/or the ascending node
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However, since optimization and rec
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is maintained in the Northern Hemis
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autonomy. It must have the ability
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[31] Neelon, Joseph G., Jr., Paul J
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Draper’s primary goal is to Drape
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)Rotordynamic Modelingof an Activel
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Eq. (9) becomes:λ[ R ] { Φ } = [
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chosen to be 24, for a total of 48
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InertialInstruments/MechanicalDesig
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BiographyJeffrey Borenstein is curr
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process step. Process information i
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Figure 4. Control chart for boron d
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References[1] Barbour, N., J. Conne
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Draper Laboratory continues to engi
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Validating the Validating Tool:Defi
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calculates miscellaneous terms, suc
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Table 1. Suggested specification sh
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User Accuracy as aFunction of Simul
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20-min averaging, this clock lockin
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Table 2. Sample high-level summary
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AcknowledgmentR.L. Greenspan, J.A.
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Systems IntegrationRich MartoranaPe
Page 131 and 132: BiographyAnthony Kourepenis is an A
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Page 135 and 136: Table 1. Summary of automotive yaw
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Page 143 and 144: An Integrated Safety AnalysisMethod
Page 145 and 146: Infrastructure ModelsSystemRequirem
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Page 155 and 156: An Optimal Guidance Law forPlanetar
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Page 165 and 166: “Draper encourages its personnel
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Page 185 and 186: monitoring of space structures and
Page 187 and 188: measured by kinematic degrees of fr
Page 189 and 190: i.e., what percent of the earth’s
Page 191 and 192: McConley, M. W.; Dahleh, M. A.; Fer
Page 193 and 194: unaffordable, or even misguided. Bu
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Page 197: Educational Activitiesat Draper Lab
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1998 - Draper Laboratory

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