Superfast rock-paper-scissors robot 'wins' every time

A robot developed by Japanese scientists is so fast it can "win" the rock-paper-scissors game against a human every single time.

The Janken robot - named after the game's Japanese name - is a faster version of one unveiled by University of Tokyo researchers in June 2012.

Version two completes its chosen hand shape almost at the same time as the human hand.

It uses high-speed recognition and reaction, rather than prediction.

Technically, the robot cheats because it reacts extremely quickly to what the human hand is doing rather than making a premeditated simultaneous action as the rules state.

Taking just one millisecond (ms) - a thousandth of a second - to recognise what shape the human hand is making, it then chooses a winning move and reacts at high speed.

Version one completed its shape 20ms after the human hand; version two finishes almost simultaneously.

The scientists at the Ishikawa Oku Laboratory, part of the University of Tokyo, specialise in a range of technologies, including "sensor fusion", which aims to replicate and improve upon the human senses using high-speed intelligent robots.

But Sethu Vijayakumar, professor of robotics at Edinburgh University, told the BBC: "These robots are really fast at reaction, but there are scenarios where even a millisecond's delay is not acceptable, such as accident avoidance or virtual stock markets.

"In these cases we need to combine high-speed reaction with high-speed prediction, using game theory and behaviour patterning."