Micro robot in small pipe with electromagnetic actuator

Millimeter size machines based on modern precision machining have various potential applications. Especially in case of a small pipe, it necessary to develop a new type of micro robot to carry an edgy current detector or CCD-camera for inspection of internal defects. Hence we attempted to design a new type of micro robot for small pipes. The dimensions of the prototype are /spl Phi/15/spl times/30 mm and the weight is 25 g. According to an experiment, it was shown this robot can climb in pipe of 20 mm diameter with a speed of about 6-8 mm/s in horizontal or in vertical under an applied voltage 12-20 volt, 30-70 Hz. This paper describes the structure and the principle of the motion of the robot.