Locating technology is the base of next instruction for robot.The main purpose of this subject is to realize the positioning of the automatic robots who participate in the contest in the playing field.According to the characteristics of the playing field

keeping-line sensor is designed as same as the arithmetic based on PID.The latitude and longitude crossing leading lines are utilized as a major basis for positioning

and combined with the code disk of the running motor

the idea of "ntegral and decimali"is used to realize precise positioning of the robots in the playing field.In practical tests

accurate position information of the robots is acquired

and experiments prove the reasonability and feasibility of this method.