Arete Associates

John Charles Dennison

Brian Edward Frazier

David C Campion

Clayton Houston Davis

Apparatus/method estimate LOS rotation, to track, approach, pursue, intercept or avoid objects. Vehicle-fixed imagers approach/recede-from objects, recording image series with background. Computations, from images exclusively, estimate rotation vs. the vehicle, applying the estimate. Preferably, recording/estimating provide proportional navigation; scan mirrors extend strapdown-sensor FOR; applying includes measuring 'range rate over range', exclusively from interimage optical flow, using results to optimize proportional-navigation loop gain; estimating includes evaluating interframe optical flow, preregistering roughly as first approximation, selecting sequence anchor points, and applying a second, finer technique developing output registration that's a coordinate translation, aligning inertial surroundings. The approximation operates optical flow with efficient embedded registration/mapping, applying a homography matrix to nearby imagery. Alternatively, inexpensive low-quality inertial sensors establish preregistration, deriving a homography matrix. When contrast in the object direction is inadequate, dual sensors yield accurate virtual imaging with an object centroid superposed into background.

Determining angular rate for line-of-sight to a moving object, with a body-fixed imaging sensor

In certain aspects, this invention is a 'control system' that detects and minimizes (or otherwise optimizes) an angle between vehicle centerline (or other reference axis) and vehicle velocity vector&#x2014;as for JDAM penetration. Preferably detection is exclusively by optical flow (which herein encompasses sonic and other imaging), without data influence by navigation. In other aspects, the invention is a 'guidance system', with optical-flow subsystem to detect an angle between the vehicle velocity vector and line of sight to a destination&#x2014;either a desired or an undesired destination. Here, vehicle trajectory is adjusted in response to detected angle, for optimum angle, e.g. to either home in on a desired destination or avoid an undesired destination (or rendezvous), and follow a path that's ideal for the particular mission&#x2014;preferably by controlling an autopilot or applying information from navigation. Purposes include real-time angle optimization to improve autopilots or guidance, and vehicle development or testing.

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Healdsburg, CA, United States of America

John Charles Dennison