You’d think pool should be an easy game for a robot to play, right? It’s all math — geometry to figure out the angles and basic physics to deal with how much force is needed to move the balls. On top of that, it’s constrained to just two dimensions, so it should be a breeze.
Any pool player will tell you there’s much, much more to the game in real life, but still, a robot to play pool against would be a neat trick. As a move toward that goal, [BVarv] wisely decided on a miniature mockup of a pool-playing robot, and in the process reinvented the pool table itself. Realizing that a tracked or wheeled robot would have a tough time maneuvering around the base of a traditional pool table, his model pool table is a legless design that looks like something from IKEA. But the pedestal support allows the robot to be attached to the table and swing around in a full circle, and this allowed him to work through the kinematics as shown in the charming stop-action video below.
[BVarv] has gotten as far as motion control on the swing axis, as well as on the arms that will eventually hold the cue. He plans overhead image analysis for identifying shots, and of course there’s the whole making it full-size thing to do. We’d love to play a game or two against a bot, so we hope he gets there. In the meantime, how about a little robo-air hockey?
Continue reading “Pool Playing Robot Destined for Trouble in River City”
If you know your way around a pool table you should be able to apply those skills to improving the sound of your home theater. [Eric Wolfram] put together a post that discusses the issues caused by unwanted sound reflections and shows how to position acoustic tiles to solve the problem.
This is a companion post to his guide on building your own acoustic tiles. Don’t worry if you haven’t gotten around to doing that yet. With just a wood frame, dense fiberglass, and some fabric they’re simple to build. They’re also easy to hang but until now you might have just guessed on where they should go.
Once you have all of your speakers and seats in position grab a mirror and some post-it notes. Take a seat as the viewer and have a friend operate the mirror as seen above. With it flat against the wall, mark each spot with a sticky-note where you can see a reflection of one of the speakers. Finding the reflection points is just like lining up a bank shot in Billiards. With five speakers (5.1 Surround Sound) and six surfaces (walls, ceiling, and floor) you should be able to mark 30 reflections points. Now decide how wild you plan to go with the project. The best result will address all 30 reflection points, but you can get by with just the front marks if you’re a bit more conservative.
Can you beat this robot at pool? This sparks something of a “let the wookie win” attitude for us, but we still love to watch the video. This is the PR2 playing pool thanks to the folks over at the Willow Garage. It uses a laser sensor to detect the legs of the pool table, and cameras to find the diamonds and balls at the playing surface rather than using an overhead camera. They cut down on the coding work needed by using FastFiz, an open source Billiards physics library. The final step was building an interface so the robot could use a cue. Check it out after the break (no pun intended).
Continue reading “The PR2 calls the shots”
Sunday we saw robots playing pool and an augmented reality pool game. Today we’ll complete the pool trifecta: virtual pool using a real cue stick and ball in another vintage video from Hack a Day’s secret underground vault. The video is noteworthy for a couple of reasons:
First is the year it was made: 1990. There’s been much buzz lately over real-world gaming interfaces like the Nintendo Wii motion controller or Microsoft’s Project Natal. Here we’re seeing a much simpler but very effective physical interface nearly twenty years prior.
Second: the middle section of the video reveals the trick behind it all, and it turns out to be surprisingly simple. No complex sensors or computer vision algorithms; the ball’s speed and direction are calculated by an 8-bit processor and a clever arrangement of four infrared emitter/detector pairs.
The visuals may be dated, but the interface itself is ingenious and impressive even today, and the approach is easily within reach of the casual garage tinkerer. What could you make of this? Is it just a matter of time before we see a reader’s Mini-Golf Hero III game here?
[Justin] sent in his Digitally Assisted Billiards project. Using a web cam, a computer and a projector, these guys have set up a system that shows you the trajectories of your current shot. It detects the angle of the cue and displays a glowing blue line showing where each ball would go and where the collisions would be. It is a bit slow right now, and made somewhat less accurate by a low resolution web camera. This could be a fantastic teaching tool if it were to get some more polish. The source code is available on the site, so you could try this one out at home.