Players control their robots to play football at the Dutch national robot cup in Delft, the Netherlands, on April 20, 2013. (Xinhua/Sylvia Lederer)
Players control their robots to play football at the Dutch national robot cup in Delft, the Netherlands, on April 20, 2013. (Xinhua/Sylvia Lederer)
Players show their robots before Dutch national robot cup in Delft, the Netherlands, on April 20, 2013. (Xinhua/Sylvia Lederer)