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Title: Error-eliminating rapid ultrasonic firing

A system for producing reliable navigation data for a mobile vehicle, such as a robot, combines multiple range samples to increase the "confidence" of the algorithm in the existence of an obstacle. At higher vehicle speed, it is crucial to sample each sensor quickly and repeatedly to gather multiple samples in time to avoid a collision. Erroneous data is rejected by delaying the issuance of an ultrasonic energy pulse by a predetermined wait-period, which may be different during alternate ultrasonic firing cycles. Consecutive readings are compared, and the corresponding data is rejected if the readings differ by more than a predetermined amount. The rejection rate for the data is monitored and the operating speed of the navigation system is reduced if the data rejection rate is increased. This is useful to distinguish and eliminate noise from the data which truly represents the existence of an article in the field of operation of the vehicle.
Inventors:
 [1];  [1]
  1. (Ann Arbor, MI)
Issue Date:
OSTI Identifier:
868899
Assignee:
University of Michigan (Ann Arbor, MI) CHO
Patent Number(s):
US 5239515
Contract Number:
FG02-86NE37969
Research Org:
University of Michigan
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
error-eliminating; rapid; ultrasonic; firing; producing; reliable; navigation; data; mobile; vehicle; robot; combines; multiple; range; samples; increase; confidence; algorithm; existence; obstacle; speed; crucial; sample; sensor; quickly; repeatedly; gather; time; avoid; collision; erroneous; rejected; delaying; issuance; energy; pulse; predetermined; wait-period; alternate; cycles; consecutive; readings; compared; corresponding; amount; rejection; rate; monitored; operating; reduced; increased; useful; distinguish; eliminate; noise; truly; represents; article; field; operation; ultrasonic energy; predetermined amount; operating speed; multiple samples; energy pulse; corresponding data; multiple sample; mobile vehicle; /367/901/