Obstacle-avoiding navigation system
Abstract
A system for guiding an autonomous or semi-autonomous vehicle through a field of operation having obstacles thereon to be avoided employs a memory for containing data which defines an array of grid cells which correspond to respective subfields in the field of operation of the vehicle. Each grid cell in the memory contains a value which is indicative of the likelihood, or probability, that an obstacle is present in the respectively associated subfield. The values in the grid cells are incremented individually in response to each scan of the subfields, and precomputation and use of a look-up table avoids complex trigonometric functions. A further array of grid cells is fixed with respect to the vehicle form a conceptual active window which overlies the incremented grid cells. Thus, when the cells in the active window overly grid cell having values which are indicative of the presence of obstacles, the value therein is used as a multiplier of the precomputed vectorial values. The resulting plurality of vectorial values are summed vectorially in one embodiment of the invention to produce a virtual composite repulsive vector which is then summed vectorially with a target-directed vector for producing a resultant vector for guiding the vehicle.more »
- Inventors:
-
- Ann Arbor, MI
- Issue Date:
- Research Org.:
- Univ. of Michigan, Ann Arbor, MI (United States)
- OSTI Identifier:
- 867775
- Patent Number(s):
- 5006988
- Assignee:
- University of Michigan (Ann Arbor, MI)
- Patent Classifications (CPCs):
-
G - PHYSICS G05 - CONTROLLING G05D - SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- DOE Contract Number:
- FG02-86NE37969
- Resource Type:
- Patent
- Country of Publication:
- United States
- Language:
- English
- Subject:
- obstacle-avoiding; navigation; guiding; autonomous; semi-autonomous; vehicle; field; operation; obstacles; thereon; avoided; employs; memory; containing; data; defines; array; grid; cells; correspond; respective; subfields; cell; contains; value; indicative; likelihood; probability; obstacle; respectively; associated; subfield; values; incremented; individually; response; scan; precomputation; look-up; table; avoids; complex; trigonometric; functions; fixed; respect; form; conceptual; active; window; overlies; overly; presence; therein; multiplier; precomputed; vectorial; resulting; plurality; summed; vectorially; embodiment; produce; virtual; composite; repulsive; vector; target-directed; producing; resultant; alternative; vectors; surrounding; computed; corresponding; density; target; location; information; select; directions; travel; densities; alternative embodiment; memory contains; target location; value corresponding; location information; look-up table; containing data; /701/180/318/
Citation Formats
Borenstein, Johann, Koren, Yoram, and Levine, Simon P. Obstacle-avoiding navigation system. United States: N. p., 1991.
Web.
Borenstein, Johann, Koren, Yoram, & Levine, Simon P. Obstacle-avoiding navigation system. United States.
Borenstein, Johann, Koren, Yoram, and Levine, Simon P. Tue .
"Obstacle-avoiding navigation system". United States. https://www.osti.gov/servlets/purl/867775.
@article{osti_867775,
title = {Obstacle-avoiding navigation system},
author = {Borenstein, Johann and Koren, Yoram and Levine, Simon P},
abstractNote = {A system for guiding an autonomous or semi-autonomous vehicle through a field of operation having obstacles thereon to be avoided employs a memory for containing data which defines an array of grid cells which correspond to respective subfields in the field of operation of the vehicle. Each grid cell in the memory contains a value which is indicative of the likelihood, or probability, that an obstacle is present in the respectively associated subfield. The values in the grid cells are incremented individually in response to each scan of the subfields, and precomputation and use of a look-up table avoids complex trigonometric functions. A further array of grid cells is fixed with respect to the vehicle form a conceptual active window which overlies the incremented grid cells. Thus, when the cells in the active window overly grid cell having values which are indicative of the presence of obstacles, the value therein is used as a multiplier of the precomputed vectorial values. The resulting plurality of vectorial values are summed vectorially in one embodiment of the invention to produce a virtual composite repulsive vector which is then summed vectorially with a target-directed vector for producing a resultant vector for guiding the vehicle. In an alternative embodiment, a plurality of vectors surrounding the vehicle are computed, each having a value corresponding to obstacle density. In such an embodiment, target location information is used to select between alternative directions of travel having low associated obstacle densities.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1991},
month = {1}
}