An amphibious and mobile robotic inspection system
is described that has been developed to test welds located inside a floating production storage oil tank (FPSO tank). The robot has
been designed to operate both in air and while submerged in oil
to test welds on structural strengthening plates and tank walls. It
operates in air when the tank has been emptied with only a few
inches of product remaining on the floor. In this case the robot
moves on the floor of the tank and inspects welds on the bottom
of the strengthening plates and the floor. The robot operates in a liquid by swimming down from a manhole in the roof of the tank and settling on the floor in the vicinity of a test area. In both air and liquid, ultrasonic sensors profile the surrounding
strengthening plates and tank walls and guide the robot
autonomously along the welds. A Cartesian scanning arm
mounted on the robot scans the welds with an ACFM probe and
performs non-destructive testing (NDT) after the robot has been
positioned correctly
