Boots – shoes – and leggings
Patent
1994-12-27
1996-09-24
Teska, Kevin J.
Boots, shoes, and leggings
364516, 36442402, 395162, 395 81, 354402, 354140, 348219, 348355, G06F 770
Patent
active
055596959
ABSTRACT:
The invention relates to a method and a self-calibrating visual time-to-contact (TTC) sensor for a mobile manned or autonomous unmanned vehicle which operates in a high speed manner and which permits the continuous, adaptive motion of the vehicle through the vehicle's environment. More specifically, the invention relates to an apparatus and method for novel use of active sensor control for aligning a camera, mounted on the vehicle, to track the direction of motion of the vehicle in order to successfully navigate in complex environments and to simplify difficult processing steps previously attempted through algorithmic means. Rather than attempting to explicitly find a focus of expansion (FOE) from image data, the invention continuously calibrates the sensor to point in the direction of the FOE, using weighted global average of the horizontal and vertical component of the optical flow. The pan and tilt angles of the visual TTC sensor are iteratively changed by the scanning mechanism in the opposite direction by small increments, biased by the global magnitude of the optical flow. In this way, the visual TTC sensor is not constrained to point in any direction at the start, and after several iterations it will point near the FOE and continue to do so as the vehicle moves. By actively centering the FOE in the image sequence, better accuracy is possible. By avoiding the focus of expansion calculation, the method becomes self-calibrating and it is faster and more robust to vibrations and sensor misalignments occurring in changing and complex indoor or outdoor environments.
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Denson-Low W. K.
Duraiswamy V. D.
Hughes Aircraft Company
Louis-Jacques Jacques
Teska Kevin J.
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