Tuesday, 4 December 2012

Holographic Technology

HOLOGRAPHY is a technique that allows the light scattered from an object to be recorded and later reconstructed so that it appears as if the object is in the same position relative to the recording medium as it was when recorded.

The image changes as the position and orientation of the viewing system changes in exactly the same way as if the object were still present, thus making the recorded image (hologram) appear three dimensional. 


Several types of holograms can be made. Transmission holograms, such as those produced by Leith and Upatnieks, are viewed by shining laser light through them and looking at the reconstructed image from the side of the hologram opposite the source.

the "rainbow transmission" hologram, allows more convenient illumination

by white light or other monochromatic sources rather than by lasers. Rainbow holograms are commonly seen today on credit cards as a security feature and on product packaging. These versions of the rainbow transmission hologram are commonly formed as surface relief patterns in a plastic film, and they incorporate a reflective aluminum coating that provides the light from "behind" to reconstruct their imagery.

BIGDOG ROBOT

BigDog is the alpha male of the Boston Dynamics robots. It is a rough-terrain robot that walks, runs, climbs and carries heavy loads. BigDog is powered by an engine that drives a hydraulic actuation system. BigDog has four legs that are articulated like an animal’s, with compliant elements to absorb shock and recycle energy from one step to the next. BigDog is the size of a large dog or small mule; about 3 feet long, 2.5 feet tall and weighs 240 lbs.


BigDog's on-board computer controls locomotion, servos the legs and handles a variety of sensors. BigDog’s control system keeps it balanced, navigates, and regulates its energetics as conditions vary. Sensors for locomotion include joint position, joint force, ground contact, ground load, a gyroscope, LIDAR and a stereo vision system. Other sensors focus on the internal state of BigDog, monitoring the hydraulic pressure, oil temperature, engine functions, battery charge and others.


In separate tests BigDog runs at 4 mph, climbs slopes up to 35 degrees, walks across rubble, climbs a muddy hiking trail, walks in snow and water, and carries a 340 lb load. BigDog set a world's record for legged vehicles by traveling 12.8 miles without stopping or refueling.


The ultimate goal for BigDog is to develop a robot that can go anywhere people and animals can go. The program is funded by the Tactical Technology Office at DARPA.