Andrew Doyle/LONDON
AEA Technology, of Didcot, UK, has patented a three-dimensional (3D) stereoscopic television system for use with standard rigid boroscopes, which it believes could have wide-ranging applications as an aerospace maintenance inspection tool.
The TV3 system is designed to enable engineers to carry out boroscope inspections in unfamiliar or cluttered environments, by providing them with a perception of depth, scale and texture. It also allows distances to be accurately measured in three dimensions.
Images are recorded through the left and right channels of the stereoscopic camera, and "interleaved" via a framestore into a 100Hz multi-scan monitor. A liquid-crystal display, mounted on the front of the monitor, polarises alternate left and right frames vertically and horizontally, respectively.
The viewer wears lightweight passive spectacles, with one lens polarised vertically, the other horizontally, allowing each eye to view the appropriate channel. Each eye views 50 frames a second, so no flicker is evident and a full-colour stereoscopic image is perceived.
Measurements can be taken by moving a computer-generated cursor in three dimensions. Steve Murphy, AEA's senior project engineer, TV and control systems says: "The system has internal reference for size [derived from the known parameters of the probe such as the convergence distance of the stereo cameras] giving a reference in space to make measurements with." This, he adds, means accurate measurements are possible, even when "zooming" the camera in or out.
Source: Flight International
