FPSO robot

Amphibious NDT Robot for Floating Production Oil Storage Tanks (FPSO)

Plate wave technique of none destructive testing

This robot is a swimming and floor moving robot inspection system to test welds located inside a floating production storage oil tank (FPSO tank). Currently these welds are inspected manually by emptying and cleaning the tank. The amphibious robot prototype that is designed to operate in air as well as submerged in water; it has been made intrinsically safe to operate in crude oil (API 20 to 40). It consists of a buoyancy tank on top that adjusts its buoyancy around neutral by controlling of mass. A depth sensor provides the feedback to regulate the depth at which the robot is required to maintain its position anywhere in the tank. Thrusters control the horizontal motion of the swimming robot.

The navigation system into the tank and the robot's orientation are controlled by four ultrasonic sensors operating at 10 KHz and a rotating ultrasonic sensor at 5 MHz profile the surrounding strengthening plates and tank walls. These sensors are used to align the robot and to guide it autonomously along welds between the floor and strengthening plates and the toe ends of the plates. The cartesian scanner carry an ACFM probe scans the welds after the robot has been positioned correctly. Due to constrained space for precise weld following special mechanisms have been designed to rotate all four wheels through turning angles between ± 180º and to independently control the speeds of all four wheels.

Countries & Year

England, Greece - 2007

Authors

Hernando Leon-Rodriguez
Jianzhong Shang
Tariq Sattar