Hands up if you’re a robot supported in part by the High Performance Support Project, Japan Sports Agency

To perfect their attacks, some of Japan’s top volleyball players are training against a robot that can mimic the tactics of opposing teams.

The Japanese Volleyball Association’s “block machine” consists of three pairs of robotic arms that move side to side in front of the net. These represent blockers – players who defend against “spikes” from the attacking team that send the ball forcefully over the net, making it hard for opposing players to return it.

“A spike is the most effective way to win points in volleyball,” says Laura Woodruff at Volleyball England. “The blocker’s job is to try to make part of the court unavailable to the attacker, whilst the attacker has to try to find space to hit the ball into.”


If the attacker gets it right, the ball flies over the net and straight onto the ground to win a point. If a blocker intercepts it, they can smash it right back over.

Experience Japan’s nature, culture and science: From Tokyo to Kagoshima on a New Scientist Discovery Tour

Robot re-enactment

Developed by researchers at the Japanese Volleyball Association and the University of Tsukuba, the block machine lets a coach program the robot arms for different training drills. If they think their team could have handled a situation in a previous game better, they can recreate the moment by positioning the arms to stand in for opposition team members. They can also mimic the tactical styles of future opponents.

To start the action, the coach presses a button and the robot arms whizz independently into place. The machine can travel 3.7 metres per second, which is faster than a player can move from one position on the court to another.

Six players from Japan’s women’s volleyball team used the robot in training sessions over eight days. Some players said they felt little difference between playing against the machine and attacking in a real game.

But because the machine’s configuration is set before the attack, the robot blockers can end up in the wrong position if the practice drill is slightly displaced on the court. The researchers plan to remedy this by adding motion sensors to the machine that could automatically adjust its position. They will present their work at the IEEE International Conference on Robotics and Automation in Singapore that starts in May.

“It is a very sophisticated device with positive feedback overall from players,” says Luca Paolo Ardigò at the University of Verona, Italy. It would be good to find out the impact the system could have on players’ performance over the course of a season, he says.