(ECNS) -- Humanoid robots competed Tuesday at Beijing’s National Speed Skating Oval, known as the “Ice Ribbon,” in qualifiers for the second World Humanoid Robot Games. All on-field actions were required to be performed autonomously.

Running through Sunday, the qualifiers feature 5v5 competitions for larger and medium-sized robots, as well as a U19 3v3 medium-size division for youth teams. Robots are grouped by height and weight, while the top-ranked teams will advance to the knockout stage.

Matches have produced both goals and surprises. In one game, a robot misread the ball and accidentally scored an own goal.

Hu Yue, competing in the 5v5 medium size division, said robot football is complex because multiple robots must coordinate while handling referee calls and communication protocols.

Tsinghua University's Huoshen Team, defending champions, added a passing module and improved shooting and movement.

Captain Guo Tong said the robots can now dribble short distances and kick consecutively, making play more fluid.

Football, with its relatively contained setting and clearly defined rules, provides a useful test for robotic movement and visual perception, Guo added.

Technologies developed on the pitch could also be applied in areas such as household services and emergency rescue.

(By Helen Mo, intern Yang Hongran)