7-axis Arm for NDT of Surfaces with Complex & Unknown Geometry

Abstract

The aim of the work described here is to design a dexterous and intelligent robotic arm to automate the non-destructive testing and evaluation of geometrically complex industrial products. The robot is required to scan contoured surfaces with ultrasonic and eddy current sensors without the need to position the test pieces precisely, thereby reducing inspection times. In addition, the arm should be lightweight so that it can be carried by wall-climbing and walking robots but at the same time it should be rugged enough to be operated in industrial environments where the tool (sensor probe) comes into contact with rigid and unknown test surfaces. To realise these aims, a seven-axis lightweight and rugged robot arm has been specially developed for non-destructive testing (NDT) and is reported here. The arm weighs 22 kg and is designed for portability, dexterity, ruggedness in an industrial environment and 1 mm repeatability. Its NDT payload is 4 kg. Current work is directed at developing a control system for the arm with a proven operating system with further work required to make the arm adapt to uncertain surfaces.