Immersion Techniques for Automated Ultrasonic Inspection of Curved Parts

Abstract

This process of inspecting a curved part can be broken down into four steps. First, the operator must input geometrical information by a “teaching” process whereby points on the surface of the part are defined. The second step is obtaining a mathematical description of the part from this geometrical information. The third step is computing a raster scan plan from the mathematical description. The final step is executing the scan plan to acquire and display the ultrasonic test results. The contour scanning method and hardware implementation described here successfully demonstrates a complete and practical approach to inspecting curved parts. It enables a large class of parts to be. inspected that cannot be handled with rectilinear scanning methods. The use of the ultrasonic signal enables the operator to teach the part without having to precisely peak the signal and set the water path. Also, the processing algorithm that defines the part from the teach points handles an unstructured r,et of points, which gives the operator even more flexibility while teaching the part. Thus, the teaching process is very quick and efficient, particularly for parts that are gently curved.