Robo-One is a robot competition category of bipedal humanoid robots. The first ROBO-ONE contest was held in Japan in 2002 and consisted of an initial judged autonomous "Demonstration" stage, followed by one-on-one matches. In Japan, ROBO-ONE has spawned a whole series of related competitions including ROBO-ONE J, ROBO-ONE Special, ROBO-ONE Grand Prix, and the ROBO-ONE Technical Conference events. ROBO-ONE type contests have been held in several other countries including South Korea (official) and the United States (unofficial held by Robogames). The robots are usually built with RC Servos as actuators and mounted together with sheet metal shapes. The most common frame material is aluminum. However, there have been entries constructed with steel, plastic, and even wood. Different sensors are used by the robot for balance and to perceive its surroundings. A small onboard micro controller or equivalent is used to control the robots movements and if the robot is autonomous it is also programmed to adjust the robots behavior in response to sensor inputs. There have been fifteen competitions in Japan. ROBO-ONE 13 was held on March 22 and 23, at Korakuen Hall" in Takamatsu. ROBO-ONE 14 occurred on October 11–12, 2008. ROBO-ONE 14 took place in at the Pacifico Yokohama Exhibition Hall. ROBO-ONE 15 was held in Kawasaki on May 4, 2009. ROBO-ONE 16 was held in Toyama City, Toyama Prefecture, on September 26–27, 2009. The 17th ROBO-ONE tournament took place in Kawasaki on March 21, 2010. A ROBO-ONE Festival was held May 22 at the Kawasaki City Industrial Promotion Hall. The festival included both ROBO-ONE Soccer and ROBO-ONE Light events. The 18th ROBO-ONE event was held in Shibata, Niigata Prefecture on August 28–29, 2010. The ROBO-ONE 19 competitions scheduled for March 19/20 in Kawasaki were canceled due to the 2011 Tōhoku earthquake and tsunami, and were held October 8–9, 2011. The 30th ROBO-ONE took place on Sunday, February 26, 2017. The 36th ROBO-ONE took place on Sunday, February 9, 2020, at Miraikan Hall, Tokyo. ROBO-ONE Events ROBO-ONE: The primary ROBO-ONE competitions take place twice a year, with the odd numbered competitions scheduled in the Tokyo area and the even numbered competitions staged in more remote locations to increase visibility and encourage participation in the sport.The first day begins with pre-screening tests that insure the entries are capable of taking a number of steps (10 steps within 10 seconds), and rising from both a supine and prone positions. This