Visionary robots

Visionary robots robots will have yet another dimension added to them to enhance the various capacities in which they can serve humans. If scientists at Israel's Weizmann Institute have their way, robots will be fitted with three-dimensional vision soon, allowing them to carry out tasks that require a perception of depth.

The researchers have developed a system that uses two video cameras that view the world through a fluorescent screen. The screen is necessary because even when equipped with two cameras to provide stereo vision, a robot has no means of judging scale to establish perspective. Israeli scientists Daniel Zajfman and Oded Heber developed the screen through work in molecular imaging.

The new system works on the simple premise that the nearer an object is to the robot, the sooner light reflecting from it will hit the screen. When a ray hits the screen, it flashes for a fraction of a second; this flash is picked up by one of the two video cameras. Rather than having a constant view, the left eye camera features a shutter that opens and shuts millions of times a second. This constantly changing view allows it to check when new bursts of light hit the screen by comparing each frame against its predecessor. Rays that arrive later are judged to be farther away from the robot.

According to Zajfman, a simple sum then tells the computer exactly how far away each object is. "If you know how far away the nearest object is when the robot begins to work and you know the speed of light, it is very simple to work out the distances involved,' he says. The calculation is done by measuring the time lapse in between direct flashes of light. The new system will suit robots that need to find their way without bumping into things.