Pool Playing Robot Shoots Five Billiard Balls in a Row (video)
Not every masters thesis will earn you street cred in a pool hall, but this one will. Thomas Nierhoff, from the Institute of Automatic Control Engineering at the Technical University of Munchen in Germany, programmed a two armed robot to shoot billiards...and to do it well. The bot, with seven degrees of freedom in each arm, was able to sink easier shots with up to 80% success, which isn't quite world class level, but definitely beats my skills. Watch Nierhoff's pool protege sink five balls in a row in the video below. Presented at last month's ICRA conference in Shanghai, Nierhoff's work demonstrates how advanced research robots are getting better at performing complex cognitive tasks. More than ever it looks like it's a question of when, not if, robots will match humans in all kinds of physical feats. The answer: sooner than you think.
The Munchen robot starts its five ball run at 1:32 in the video below. Make sure to watch until the end to catch more examples of the bot's successes (and failures) at shooting pool.
Nierhoff (in cooperation with Omiros Kourakos and Sandra Hirche) tested the robot in 400 separate shooting situations. While able to sink nearly 80% of the easiest shots, the robot did progressively worse as shots became more difficult. That's to be expected, but its closer to 30% success for the hardest situations would make me think twice before betting any money on the robot's skills in a real pool game.
Overall, the Munchen robot was pretty impressive, but it's not the first pool shooting bot we've seen. Willow Garage's PR2 wowed us with it's snooker skills almost exactly a year ago. While the Munchen robot relies on an overhead camera, the PR2 did all its visual analysis using onboard sensors. The latter is more impressive to me, though I appreciate the ability of humans to piggy back on the Nierhoff system to improve their game (see the video above at 1:21). On the other hand, the PR2 required a special adapter tool to hold the cue and get a smooth stroke on its shots, while the Munchen robot used nothing but its own hands. The circumstances surrounding each project are perhaps equally matched as well: Munchen's was a master's thesis, not a mainline endeavor, and Willow Garage put together their demo in a single week.
If the two robots went head to head in a match, it's hard to imagine which would win in a contest. Luckily we don't need our imaginations. The Technical University of Munchen received a PR2 in Willow Garage's give away last year. The PR2's hosts at TUM, the Intelligent Autonomous Systems group, should bring their bot over to the Institute of Automatic Control Engineering lab and see how the two robots do in a real contest. I mean, the software for the PR2 is openly available on ROS, how hard could it be to get a competition going?
The real match up of the 21st Century, however, will be robot versus humans. While robot soccer teams are hoping to compete with World Cup caliber humans by 2050, robot pool could be ready decades earlier. In situations where they don't need bipedal walking, balancing, or difficult dynamic motions, robots are going to be our equals in physical performance fairly soon. In many ways, they've already surpassed us - just look at manufacturing plants the world over. Nierhoff may have been producing a cool demonstration of his programming skills for his thesis, but he was also showing us how easily robots could be adapted to even the most human of activities: having fun. Good luck to the new engineer and his colleagues in Munchen, I'm sure their next project will be even more amazing.
...especially if it's a pool competition with the PR2.