Abstract: The control method of tracking rectangle-corner fillets based on wheeled mobile robot with rotational arc sensor is researched. For the lined welding seam tracking, a multi-segment controller is designed which is composed of a proportion controller and a self-turning fuzzy controller to control horizontal slider. When the deviation is large the proportion controller will be used to quickly reduce the deviation, otherwise the self-turning fuzzy controller will be used to avoid overshoot and achieve smooth tracking, and the immunity feedback method is used to modify proportion gene of fuzzy controller. A kinematics mathematical model of robot is built for tracking rectangle-corner fillet seams. The welding torch inclination is used to detect rectangle corner, and ultrasonic sensor is used to detect the frontage welding seam position. A fuzzy compromise controller is designed to carry out coordinated control of wheels and horizontal slider of robot. Actual welding test proves the effectiveness of the method.

Key words: Fillet, Mobile welding robot, Rotational arc sensor, Welding seam tracking