Lasers help pool players pot balls

06 Nov 2002

Pool players can now hone their potting skills thanks to a laser-based interactive imaging system called James.

The days of wayward and fluke pool shots could be numbered thanks to an interactive imaging system developed by researchers at Aalborg University in Denmark. The table uses a laser to highlight the optimal path the cue ball should take during each shot and an interactive coach rates the player's performance throughout the session.

Projecting positions

In a typical session, a user selects the shots they want to practice by speaking to the interactive coach, called James, or navigating through menus on a touch screen. "The system has speech recognition so you can talk to it but only in short phrases and commands," research leader Lars Bo Larsen told Optics.org. "You communicate via wireless head-mounted microphone, which lets you move freely round the table."

Laser precision

The laser system is suspended above the table. Once the practice shots have been selected, the system projects laser-drawn circles onto the table to tell the user where to place the balls. "The laser then projects a target area where the cue-ball is supposed to end up," explained Larsen.

Target practice

A camera, also mounted above the table, monitors the path taken by the balls. Larsen says that, when the balls stop after your shot, the system calculates a score based on where the balls end up relative to the target. It then comments on the result and then resets the laser to play the shot. Players can also ask James to switch the laser guidelines off or on.

The current system uses a x-y scanner to project a flicker-free continuous-line red beam onto the green table surface. In their paper presented at the International Conference on Multimodal Interfaces last month, Larsen and colleagues explained that this is not ideal. "If the path gets very long, the beam will become too dim," report the authors.

As well as pool, Larsen says that his group has used the setup for other games such as virtual air-hockey. He added though that he has no plans to commercialize the system.

Author
Jacqueline Hewett is news reporter on Optics.org and Opto & Laser Europe magazine.