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Showing papers on "Obstacle published in 1972"


Proceedings ArticleDOI
22 May 1972
TL;DR: In this article, the dielectric image line is treated as an example of a line that can support a surface-wave mode, and reflections from metallic obstacles on the line are considered.
Abstract: The dielectric image line is treated as an example of a line that can support a surface-wave mode, and reflections from metallic obstacles on the line are considered. This problem finds its application in an obstacle detection scheme for guided ground transportation where the metallic obstacle may represent a preceding vehicle. An integral equation for the currents on the obstacle is solved by the moment method and the surface-wave reflection coefficient is obtained.

44 citations


Patent
T Jones1
17 May 1972
TL;DR: In this article, an apparatus for determining when the size of an obstacle in the path of a vehicle is greater than a predetermined minimum including a plurality of narrow angle photosensitive detectors and laser emitters is presented.
Abstract: An apparatus for determinng when the size of an obstacle in the path of a vehicle is greater than a predetermined minimum including a plurality of narrow angle photosensitive detectors and laser emitters. The photosensitive detectors and laser emitters are displaced geometrically to generate a unique sensing zone for each photosensitive detector, the sensing zones being spaced one from another such that the distances there-between are representative of an obstacle of interest when the obstacle spans a predetermined number of sensing zones. The outputs of the photosensitive detectors are monitored and when the obstacle spans the predetermined number of sensing zones, an output is generated to provide an indication that the size of the obstacle is greater than the predetermined minimum.

15 citations





Journal ArticleDOI
TL;DR: In this article, the Navier-Stokes equations were applied to flow past a semi-infinite flat plate and a smooth bounded obstacle in the context of flow past an obstacle, and it was shown that the lift acting on the obstacle has the same magnitude and opposite sense as the lift on the plate, independent of the shape or location of the obstacle.
Abstract: The problem of flow past a semi-infinite flat plate and a smooth bounded obstacle is studied within the framework of the Navier–Stokes equations It is shown that the lift acting on the obstacle has the same magnitude and opposite sense as the lift acting on the plate, independent of the shape or location of the obstacle

2 citations


31 Dec 1972
TL;DR: A four wheeled rover of unusual mobility and maneuverability was further refined and tested under both laboratory and field conditions, and a second major effort was made to develop autonomous guidance.
Abstract: Investigation of problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars has been undertaken. Problem areas receiving attention include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis; terrain modeling and path selection; and chemical analysis of specimens. The following specific tasks have been under study: vehicle model design, mathematical modeling of a dynamic vehicle, experimental vehicle dynamics, obstacle negotiation, electromechanical controls, collapsibility and deployment, construction of a wheel tester, wheel analysis, payload design, system design optimization, effect of design assumptions, accessory optimal design, on-board computer sybsystem, laser range measurement, discrete obstacle detection, obstacle detection systems, terrain modeling, path selection system simulation and evaluation, gas chromatograph/mass spectrometer system concepts, chromatograph model evaluation and improvement.