Sensors track martial arts blows

Ubiquitous computing aims to allow a wide range of usually non-computer aided human activities to take advantage of computer processing by planting sensors throughout an environment and moving computers into the background.

Researchers from Palo Alto Research Center (PARC), Stanford University, and Impact Measurement have brought computers into a martial arts sparring ring with a system that senses the force of a hit.

The researchers are testing the system in tae kwon do matches. Information from the sensors combined with the judges' calls makes for more accurate scoring, according to the researchers. The method could also be used for sensing impact in other contact sports and also for videogames.

Tae kwon do competitors earn points for accurate, powerful kicks delivered to a scoring region of a competitor's body. The system uses wireless piezoelectric pressure sensors planted in the hogu, or body protector worn by a competitor. Piezoelectric materials transfer vibration into electricity and vice versa. The sensors transfer the force of impact into a readable electrical signal that is wirelessly transmitted to a laptop base station.

The system includes wireless handsets for the three judges, and each sensor score has to be confirmed in real-time by a least two of the judges. The sensor and handset data is processed by the laptop, which also controls a score display.

The system is a more sophisticated version of the decades-old fencing scorer, which uses wires and records contact but not force.

The method can be used now, according to the researchers.