Path Planning of Scanning Robot for Tubular Joint

The path planning is one of keys to carrying out ultrasonic automatic inspection for tubular joints of T K and Y types. Based on the scanning theory of ultrasonic phased array, a three degrees of freedom(DOFs) scanning robot was developed for automatic inspecting welds. The scanning robot with the phased array probe adheres to the outside of branch pipe at inspecting. The weld tracing of the probe is realized by 2 DOFs' motion of scanning robot, and the pose can be controlled by the other DOF. On the geometry analysis of intersected welds, the path planning of probe was put forward, and the movements of joints were simulated. The results of simulation indicate that the path is rational, and the method avoids the complicated transformation of coordinate, and lays the foundation for controlling the scanning robot to inspect the tubular joint welds.