Title :
Error analysis of combined optical-flow and stereo passive ranging
Author_Institution :
NASA Ames Res. Center, Moffett Field, CA, USA
fDate :
10/1/1992 12:00:00 AM
Abstract :
Optical-flow ranging in which the stream of two-dimensional images obtained from a forward-looking forward-moving passive sensor is used to compute range to points in the field of view, and triangulation based on stereo images obtained from at least two stationary sensors are combined. The potential accuracies of the combined optical flow and stereo passive-ranging system are analyzed in the context of helicopter nap-of-the-earth obstacle avoidance. The Cramer-Rao lower bound (CRLB) is developed for the combined system under the assumption of a random angular misalignment common to both cameras of a stereo pair. It is shown that the range accuracy degradations caused by misalignment are negligible compared to those for a monocular optical-flow system
Keywords :
aircraft instrumentation; error analysis; helicopters; image sensors; position measurement; safety systems; sensor fusion; stereo image processing; Cramer-Rao lower bound; accuracy; cameras; forward-looking forward-moving passive sensor; helicopter; nap-of-the-earth obstacle avoidance; optical-flow; random angular misalignment; stationary sensors; stereo passive ranging; triangulation; two-dimensional images; Cameras; Degradation; Error analysis; Helicopters; Image motion analysis; Image sensors; Intelligent sensors; Optical sensors; Optical transmitters; Vehicles;
Journal_Title :
Aerospace and Electronic Systems, IEEE Transactions on
