An Automated Robotic Approach for Inspection of Metallic Tubular Structure

Abstract

Electro Magnetic Acoustic Transducer (EMAT) is one of the Ultrasonic Testing (UT) techniques frequently used for flaw detection, thickness measurements, and characterization of metals and metallic alloys. However, the manual inspection of components or structures using EMAT has several drawbacks. Firstly, it can be time-consuming, labor-intensive, and physically demanding, mainly if the components or structures are located in remote or hard-to-reach areas. Moreover, manual inspection is susceptible to human error and subjectivity, leading to inconsistencies and inaccuracies in the inspection results. Finally, a manual inspection can be expensive, especially if specialized equipment or personnel are required. To overcome these problems, we have designed a robotic system that contains two Universal Robots (UR) with a customized gripper attached to its tooltip. These grippers have EMAT sensors attached to the fingertips and a camera to help identify the position of the pipe. We made a few modifications to the gripper to optimize the point of contact and ensure that the EMAT sensors make good contact with the pipe. The attached stereo depth camera to the back of the gripper is used to get positional feedback for the UR5 robotic arms. We incorporated simple fiducial markers onto the pipe setup such that they were placed on spots on the pipe where we wanted to perform our tests. With the help of the stereo camera, we obtained the real-time position of these fiducial markers. We generated a motion path for the robotic arms to move from one position to another.