Apparatus and method for self-calibrating visual time-to-contact sensor
US5559695A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 27, 1994 |
| Grant date | Sep 24, 1996 |
| Priority date | — |
| Expiry date | Dec 27, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D1/0276
- WIPO fieldControl
- WIPO sectorInstruments
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 …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.