I. Introduction
As the development of science, the application of artificial intelligence has expanded to many different fields, the requirement of the capability of robots is much higher than past. And the mobile robot obstacle avoidance technology comes out for requirement. For the long developing time of mobile robot obstacle avoidance technology, it evolved a style of it's own as a kind of subjects. It often refers to two topics, the principium of multi - channel ultrasonic distance and the arithmetic of the mobile robot obstacle avoidance technology. As another function of this programmer is leading the robot to a target, this technology got a new name called path planning method for mobile robot.