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CONF ON sensors AND sensor systems FOR guidance AND navigation 2

作者： SHEMWELL, DM VETTER, AA GELLERT, RI Humbug Mountain Research Labs. (United States)

ISBN: (纸本)081940859X

The Laser Centerline Localizer (LCL) and the laser Glideslope Indicator (LGI) use a series of low power, but highly visible laser beams to illuminate approach corridors for carrier flight operations. By taking advantage of the ability to precisely shape and direct visible laser beams and by encoding the illuminated paths using color and temporal frequency, direct visual signals which provide a positive on course signal as well as an indication of the direction and degree of deviation from the proper approach are seen by the pilot. The LCL provides centerline guidance and the LGI provides descent guidance. This laser visual landing aid (LVLA) system provides the pilot with significantly improved visual cues to aid in the safe landing of the aircraft. The LCL and LGI units have been constructed and field tested. The ability to guide pilots from a range of over 15 miles has been demonstrated.

关键词： Liquid crystal lasers Visualization Fluctuations and noise Lutetium Video Cameras Fourier transforms Remote sensing Space operations Tolerancing

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MICROFABRICATED MAGNETOMETER USING YOUNGS MODULUS CHANGES IN MAGNETOELASTIC MATERIALS 2

MICROFABRICATED MAGNETOMETER USING YOUNGS MODULUS CHANGES IN...

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CONF ON sensors AND sensor systems FOR guidance AND navigation 2

作者： FENN, RC GERVER, MJ HOCKNEY, RL JOHNSON, BG WALLACE, JL SatCon Technology Corp. (United States) Centro de Investigacion y de Estudios Avanzados del I.P.N. (Mexico)

ISBN: (纸本)081940859X

Recent advances in tunneling-tip technology, magnetic materials, and microfabrication techniques allow development of a new class of improved magnetometers. The sensor utilizes changes in Young's modulus of amorphous magnetic alloys resulting from their excellent magnetoelastic properties. Changes in applied magnetic field cause resonant frequency changes of a sputtered, electrostatically excited Metglass cantilever. Resonant cantilever position is measured by a second, electrostatically controlled cantilever holding a tunneling-tip that tracks the Metglas cantilever. The phase relationship between the exciting signal and the position is fed back to maintain the excitation frequency at the moving resonant peak. In this way the resonant frequency is measured, and the field is inferred from the frequency. The 'Q' of the Metglas cantilever is increased to very high levels using closed loop control of cantilever dynamics, producing extraordinary resolution.

关键词： sensors Magnetism Magnetometers Magnetic sensors Silicon Microfabrication Actuators Etching Semiconducting wafers Information operations

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ADVANCED AIRBORNE 3D COMPUTER IMAGE GENERATION systems TECHNOLOGIES FOR THE YEAR 2000 2

ADVANCED AIRBORNE 3D COMPUTER IMAGE GENERATION SYSTEMS TECHN...

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CONF ON sensors AND sensor systems FOR guidance AND navigation 2

作者： BRIDGES, AL SCI Systems Inc. (United States)

ISBN: (纸本)081940859X

An airborne 3-D computer image generation system (CIGS) is a modular avionics box that receives commands from and sends status information to other avionics units. The CIGS maintains a large amount of data in secondary storage systems and simultaneously drives several display units. Emerging requirements for CIGS include: advanced avionics system architecture requirements and BIT/fault tolerance; real-time operating systems and graphic interface languages in Ada; and geometric/pixel processing functions, rendering system, and frame buffers/display controllers for pictorial displays. In addition, podded sensors (FLIR, LLTV, radar, etc.) will require multiplexing of high-resolution sensor video with graphics overlays. A combination of head-down AMLCD flat panels, helmet-mounted display (HMD), and Head-Up Display (HUD) will require highly parallel graphics generation technology. Generation of high-resolution, real-time 2-D/3-D displays with anti-aliasing, transparency, shading, and motion, however, emphasizes compute-intensive processing. High-performance graphics engines, powerful floating point processors, and parallel architectures are needed to increase the rendering speed, functionality and reliability, while reducing power, space requirements, and cost. The CIGS of the future will feature special high speed busses geared toward real-time graphics processing. The CIG system will be multi-channel, will have a high addressable resolution to drive HUD, 3-D displays in 4-pi-steradian virtual space, and 3-D panoramic displays; and will include fiber optics video distribution between CIG and display units. The head-down display (HDD) is by far the most complex display in that both background and overlay display elements are required. The background is usually generated from terrain/cultural features data. Terrain data is used to generate 2-D map backgrounds or 3-D perspective views duplicating or substituting for the pilot's out-the-window view. Performance of 150,000 t

关键词： Heads up displays Visualization Copper indium gallium selenide 3D displays Computing systems Head-mounted displays Video Flat panel displays 3D image processing sensors

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guidance control scheme employing knowledge-base for AGV navigation

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Proceedings of the 1992 American Control Conference

作者： Rajagopalan, R. Cheng, R.M.H. Lequoc, S. Concordia Univ Montreal Que Canada

ISBN: (纸本)0780302109

This paper presents a feed forward control scheme for AGV guidance employing a knowledge-base. The function of this control scheme is to identify the geometric nature of the track and guide the vehicle accordingly. In addition to this, guidance is carried out based on the requirement of positioning the AGV relative to the track profile, i.e. desired values of the position and orientation offsets of the longitudinal axis of the vehicle relative to the track are established. Hence this guidance control scheme provides flexibility in terms of specifying which part of the AGV body has to follow the track. Since vehicle guidance is based on the feedback information from the sensors over a period of time, accurate track following of a larger segment of the track is achieved. Mathematical formulations are presented to identify the track geometry and to compute the desired values of the position and orientation offsets using the sensor data and a mathematical description of the vehicle geometry.

关键词： navigation systems

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SHIP SHADOW MEASUREMENTS OBTAINED FROM A MANNED SUBMERSIBLE 11

SHIP SHADOW MEASUREMENTS OBTAINED FROM A MANNED SUBMERSIBLE

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CONF ON OCEAN OPTICS ii

作者： SPINRAD, RW WIDDER, EA Office of Naval Research (United States) Harbor Branch Oceanographic Institution (United States)

ISBN: (纸本)0819409235

Measurements of ship shadow were made from a manned submersible, equipped with a downwelling PAR irradiance sensor. These measurements were made as transects under the surface ship during clear sky conditions and three separate profiles (on the shady side, under the ship, and on the sunny side) during overcast conditions. Results from the clear sky measurements agree with previous numerical simulations, indicating only small errors due to ship shadow. During overcast conditions, the profiles indicate the shadow effects are detectable to considerable depth, but not at a distance of one optical depth from the ship rail on the sunny side. These measurements also demonstrate the effectiveness of manned submersibles for optical oceanographic studies.

关键词： Ocean optics Sun Signal attenuation sensors Optical testing Monte Carlo methods navigation systems Chromium Numerical simulations Reflectivity

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Structural design of the GN&C navigation Base for the Space Station Freedom

Structural design of the GN&C Navigation Base for the Space ...

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Proceedings of the 3rd International Conference on Engineering, Construction, and Operations in Space iiI

作者： Grant, Lavonia Cutting, Fred Honeywell Inc Largo United States

ISBN: (纸本)087262868X

The Space Station Freedom (SSF) pointing accuracy budget requires that the guidance, navigation and Control hardware maintain alignment within ± 0.1 degrees of arc. The ring laser gyros (RLG) and the inertial sensor assembly (ISA) maintain the SSF's knowledge of its orientation in inertial space. The Star Tracker (ST) sensors identify star positions to compensate for RLG drift, and a Kalman filter compensates for changes in alignment between the Star Trackers and the RLG. The thermal drift of the Star Tracker orientation with respect to SSF is controlled by the mounting base named the 'Nav Base'. The Nav Base is a plate structure designed to support the ISAs and orient the Star Trackers. No electronic compensation is planned for thermally induced changes in Star Tracker orientation. The budgeted allowance for thermal drift of the Nav Base is ±60 arc sec. The design approach to assess Nav Base thermal distortion is to use the TRASYS thermal radiation model and SINDA thermal analyzer to provide Nav Base temperatures and temperature gradients. The mounting of the Nav Base to the SSF will be through thermal and structural isolation springs. Both sides of the Nav Base will be covered with ten layers of multi-layer insulation (MLI). The objective is to create an adiabatic plate with near zero thermally induced strains. The initial efforts were to determine the order of magnitude of the alignment problems between the ISAs and Star Trackers caused by thermally induced strain.

关键词： Space Stations

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Automatic guidance and control laws for helicopter obstacle avoidance

Automatic guidance and control laws for helicopter obstacle ...

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IEEE International Conference on Robotics and Automation (ICRA)

作者： V.H.L. Cheng T. Lam NASA Ames Research Center CA USA Sterling Software Inc. Palo Alto CA USA

The authors describe the implementation of a full-function guidance and control system for automatic obstacle avoidance in helicopter nap-of-the-earth (NOE) flight. The guidance function assumes that the helicopter is sufficiently responsive so that the flight path can be readily adjusted at NOE speeds. The controller, basically an autopilot for following the derived flight path, was implemented with parameter values to control a generic helicopter model used in the simulation. Evaluation of the guidance and control system with a 3-dimensional graphical helicopter simulation suggests that the guidance has the potential for providing good and meaningful flight trajectories.< >

关键词： Automatic control Helicopters navigation Vehicles Image sensors NASA sensor fusion Safety Control systems Laser feedback

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TALONS 95 GHz radar sensor for autonomous landing guidance

TALONS 95 GHz radar sensor for autonomous landing guidance

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IEEE National Conference on Aerospace and Electronics (NAECON)

作者： K.L. Koester W. Vaillancourt Norden Systems Inc. Norwalk CT USA

TALONS (Tactical Avionics for Low-Level navigation and Strike) is a pod-mounted 95 GHz radar sensor which was developed under a joint US Air Force Army contract. It incorporates a full polarization matrix, circularly polarized transmitter/receiver as well as an elevation monopulse. Ground tests of the Norden-developed TALONS 95 GHz radar sensor were conducted at the Wright laboratory in support of both the USAF autonomous landing guidance program and the FAA/USAF synthetic vision program. An independent test support contractor was used to conduct the tests, collect, reduce, analyze, and report on the data. The TALONS radar was operated under various adverse weather conditions including rain, fog, smoke, and snow. Radar backscatter data were taken of a runway/taxiway system at realistic depression angles in various weather conditions to determine the effects of precipitation and fog. The data were analyzed and utilized to produce radar imagery. Radar cross sections of several tactical targets were also measured.< >

关键词： Testing Radar imaging Radar cross section Polarization Meteorological radar Aerospace electronics navigation Force sensors Contracts Transmitters

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IMPROVED NOISE REJECTION IN AUTOMATIC CARRIER LANDING systems

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JOURNAL OF guidance CONTROL AND DYNAMICS 1992年第2期15卷 509-519页

作者： MOOK, DJ SWANSON, DA ROEMER, MJ NOURY, R BELL AEROSP TEXTRON BUFFALONY 14240

A technique for reducing the effect of sensor noise in automatic carrier landing systems (ACLS) is developed. For demonstration purposes, the effect of radar noise on the altitude control portion of an ACLS is studied using digital computer simulation. A noise rejection filter, which blends model estimates of the plane's vertical velocity and acceleration with altitude information obtained by radar, is added to the tracking/control algorithm to decrease the sensitivity to noise. However, this results in an unacceptable increased sensitivity to turbulence. An optimization of the tracking/control gains is then performed to prevent degradation of the system's response to turbulence while simultaneously achieving high noise rejection and adequate transient response. In the simulation, a 90% improvement in noise rejection capability is achieved using the new tracking/control algorithm, without increased turbulence response.

关键词： Automatic Carrier Landing System State Space Representation Radar Measurement Acceleration sensors Digital Computers Control Algorithm Power Spectral Density Flight Data Aeroplane Inertial navigation System

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Fast and auto-adaptative morphological segmentation for implementation in a 3-D vision sensor

Fast and auto-adaptative morphological segmentation for impl...

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IEEE International Symposium on Industrial Electronics (ISIE)

作者： T. Quiguer P. Miche R. Debrie LCIA INSA Rouen Mont Saint Aignan France INSA de ROUEN Mont Saint Aignan France

An intelligent 3-D vision sensor is under development in the authors' laboratory for applications in robot guidance and autonomous vehicle control. The aim in this context is to compute a depth map from two images (512*512*8 bits) in less than 0.1 seconds. The state of the field indicates the necessity for the development of new, fast, auto-adaptive operators to segment images meeting two constraints: short computational times, and automatic primitive extraction. For this reason the authors have introduced a new operator to segment image-lines: a morphological gradient with moving kernel dimension. This operator is described.< >

关键词： Image segmentation Intelligent robots Intelligent sensors Intelligent vehicles Robot sensing systems Robot vision systems navigation Remotely operated vehicles Mobile robots Automatic control

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