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Title: Method for laser-based two-dimensional navigation system in a structured environment

A low power, narrow laser beam, generated by a laser carried by a mobile vehicle, is rotated about a vertical reference axis as the vehicle navigates within a structured environment. At least three stationary retroreflector elements are located at known positions, preferably at the periphery of the structured environment, with one of the elements having a distinctive retroreflection. The projected rotating beam traverses each retroreflector in succession, and the corresponding retroreflections are received at the vehicle and focussed on a photoelectric cell to generate corresponding electrical signals. The signal caused by the distinctive retroreflection serves as an angle-measurement datum. An angle encoder coupled to the apparatus rotating the projected laser beam provides the angular separation from this datum of the lines connecting the mobile reference axis to successive retroreflectors. This real-time angular data is utilized with the known locations of the retroreflectors to trigonometrically compute using three point resection, the exact real-time location of the mobile reference axis (hence the navigating vehicle) vis-a-vis the structured environment, e.g., in terms of two-dimensional Cartesian coordinates associated with the environment.
Authors:
 [1] ;  [2] ;  [2]
  1. (Sandia Park, NM)
  2. (Albuquerque, NM)
Publication Date:
OSTI Identifier:
866812
Report Number(s):
US 4796198
DOE Contract Number:
AC04-76DP00789
Resource Type:
Patent
Research Org:
AT & T CORP
Country of Publication:
United States
Language:
English
Subject:
method; laser-based; two-dimensional; navigation; structured; environment; power; narrow; laser; beam; generated; carried; mobile; vehicle; rotated; vertical; reference; axis; navigates; stationary; retroreflector; elements; located; positions; preferably; periphery; distinctive; retroreflection; projected; rotating; traverses; succession; corresponding; retroreflections; received; focussed; photoelectric; cell; generate; electrical; signals; signal; caused; serves; angle-measurement; datum; angle; encoder; coupled; apparatus; provides; angular; separation; lines; connecting; successive; retroreflectors; real-time; data; utilized; locations; trigonometrically; compute; resection; exact; location; hence; navigating; vis-a-vis; terms; cartesian; coordinates; associated; reference axis; electrical signals; electrical signal; laser beam; signal caused; rotating beam; corresponding electrical; mobile vehicle; rate corresponding; photoelectric cell; angle encoder; /701/180/250/318/356/901/