|Flight Control Unit sensors: Part 2||- FMU Sensors 2|
Although the 18 x 18 element CMOS photosensor was developed for use in motion sensing for mice, this same IC can be used with a lens to monitor the motion of the UAV over terrain in both X and Y direction. The movement of the underlying image across the CMOS sensor array is referred to as the " optic flow" .
The four quadrant pointing angle detector is used with a lens to detect when the leans plus four quadrant detector is pointing at a light source, such as the sun, or a laser spot. When the detector plus lens assembly is pointing directly at the light souce, the photocurrent outputs from each of the four detectors is equal. In a Flight Management Unit, the four quadrant detector could point at the sun or moon, and the changes in the pointing angle would be indicative of a change in attitude of the UAV.
A paper on "Silicon Photodiode Theory" can be read here:
Use a four quadrant detector pointing at the sun or moon to detect:
Thanks to Josh Levine for bringing this thermopile sensor to our attention.
- from 1033_paparazzi.pdf on "Build you own UAV"