Climbing robot for advanced high-temperature weld bead inspection

High-temperature industrial inspection has several challenges, especially if it is an autonomous inspection through mobile robots. This paper introduces the mobile robot CRAS (Climbing Robot for Advanced inSpection) for autonomous non-destructive testing (NDT) of weld beads from industrial super-duplex stainless steel vessels. It covers the design process, previous works, main challenges, and field testing. The main objective of the robot is to perform ultrasonic inspection over a heated separator tank while it operates. The metallic surfaces of the structure to be inspected are under constant high temperatures (80 °C–135 °C) when in operation. CRAS presents magnetic wheels as an adhesion method and a perception system able to identify and follow weld beads. The NDT method uses the phased-array ultrasonic technique. This paper approaches and proposes a solution for three challenges due to the high temperature: the loss of robot adhesion, ultrasound signal deformation, and the risk of damaging sensitive equipment such as sensors, cameras, and any electronic component. The CRAS adopted solutions are detailed and future steps of CRAS development are also addressed.