Japanese robot wins Rock, Paper, Scissors every time

Janken-playing 'bot only needs one thousandth of a second to beat you at decision-making game.

Comments Off on Japanese robot wins Rock, Paper, Scissors every time November 6, 2013
Mike McLeod

Nov-13-robot-rock-paper-scissors-360Researchers at Tokyo University’s Ishikawa Oku Laboratory have developed a robotic system that can’t lose a round of Rock, Paper, Scissors (called janken in Japan) when matched against a human opponent. The only problem is, it has to cheat.

To maintain its flawless winning streak, the system takes advantage of humans’ relatively slow reaction and visual perception speed. On average, the researchers say, it takes approximately 60 milliseconds for a person’s hand, from start to finish, to form one of the game’s three hand gestures. That’s also about as fast as humans can perceive motion.

By contrast, the robot’s three-fingered hand is connected to a high speed camera that perceives and correctly determines the hand position of its human opponent in one millisecond; that is, as the rock, paper or scissors gesture is being formed. It then takes another 20 millisecond for the robot hand to form the winning hand sign, which is fast enough to finish making the gesture at the same time as, or even a moment ahead of, the human player.

While cool, and potentially unnerving, the researchers say the technology’s intent is to make robot systems better suited to working closely with humans. After all, if the robotic systems on a manufacturing line, for example, see what you’re going to do before you do, there’s less chance for collision and injury. Just leave your robotic friend at home unless you want to forget about riding shotgun again or being the first to hit on the cutie at the end of bar.