ROV DEPLOYED NODE CLEANING AND INSPECTION

Objective

The aim of the project is to develop, manufacture and test a node cleaning and inspection system which can be deployed by an existing working ROV.
In particular, the project will concentrate on :
- designing attachment systems which overcome the limitations of present-day systems,
- use of a high performance manipulative system in either a computer aided telemanipulation of robotic mode for deploying various NDT and cleaning end effectors,
- development of marinised MPI and Eddy Current systems for deployment by the manipulator arm.
The general architecture of the system is based upon :
- A large work ROV which carries a toolskid containing all necessary equipment to perform cleaning and inspection, i.e. M.P.I and Eddy Current equipment, docking arm mountings, pumps and controls, toolskid telemetry system for all control and data transmission between toolskid and surface control cabin, ROV interfaces (mechanical, hydraulic and electrical), manipulator arm and manipulator shoulder movement compensation sensors, tool posts for NDT probes and other equipment, balancing weights, buoyancy, etc.
- Two arms with 3 degrees of freedom provided on the toolskid for platform attachment purpose; once the ROV has positioned itself near the inspection area, the two arms with suction pads will be fixed on the structure, and then the arm joints hydraulically locked.
- A motion compensation system to compensate any residual movements in the manipulator shoulder and improve manipulator accuracy at the end effector.
- One CYBERNETIX force feedback manipulator arm and control system, composed of slave arm, slave arm telemetry, master and slave arms surface controllers basic operator interface (computer aided telemanipulation functions and robotic control) and mini master arm.
- A graphic interface which shall give the operator a view of the inspection area and produce a mathematical model in the controlling computers, an environmental acquisition and calibration of the model being done using a static video picture of the node. The mathematical model created from the environmental acquisition can than be used for trajectory programming of the manipulator and effector movements. The graphic package will also allow task description and job programming, trajectory alteration and defect recording and reporting.
The cleaning will be performed with water blasting methods to the necessary standard before inspection starts. Use of trajectory programming will increase the efficiency of the cleaning, but cleaning can also be performed in manual mode.
The MPI will be performed by the manipulator carrying a threader bar-derived magnetization system, assisted by an additional yoke for transverse defects, and containing necessary visual equipment, lights, ink supply, etc. The yoke will be placed on the inspection area and moved along the programmed trajectory in steps. Defect sizing will be done on the video picture showing the area under inspection. Position information will be given from the arm controllers when the operator need such information.
Eddy Current inspection will be performed in a similar way, but using the E.C probe instead. The probe will follow the programmed trajectory, while a constant pressure is applied to keep a constant lift-off and the operator will be able to stop or reverse movements if defects are indicated on E.C. display.
Each detected defect will be stored on a dedicated file, by a PC computer.
The project consists of the following 6 work packages :
WORK PACKAGE NR 1 DEFINITION OF THE OVERALL ARCHITECTURE OF THE SYSTEM
- Preparation of initial specifications (details of structures to be inspected, definition of operating and environmental conditions, NDT requirements).
- Conceptual designs (inventory of possible system configurations, costs, operating performance,. . . ),
- Selection of architecture to be retained for detailed design phase.
WORK PACKAGE NR 2 - PRELIMINARY DEVELOPMENT OF NDT TECHNIQUES
Preliminary studies of ROV deployed NDT techniques, problems to be solved and alternatives to investigate :
- MPI,
- EDDY CURRENT crack detection.
WORK PACKAGE NR 3 - DETAILED DESIGNS OF TOOLING
- attachment system,
- manipulator arm system,
- integration to ROV.
WORK PACKAGE NR 4 - PROCUREMENT, MANUFACTURE AND FACTORY TESTING OF COMPONENTS
- attachment system,
- manipulator arm system,
- teletransmission,
- cleaning system,..
WORK PACKAGE NR 5 - INTEGRATION TO AN ROV ANDSHALLOW WATER TEST
WORK PACKAGE NR 6 - DETAILED DEVELOPMENT OF NDT SENSORS
- MPI,
- EDDY CURRENT crack detection.

Programme(s)

ENG-HYDROCARB 2C - Programme (EEC) of support for technological development in the hydrocarbons sector, 1986-1989

Topic(s)

1.1 - AUXILIARY SHIPS AND SUBMERSIBLES

Call for proposal

Data not available

Funding Scheme

DEM - Demonstration contracts

Coordinator

STOLT COMEX SEAWAY SA

EU contribution

No data

Address

CHEMIN DU LITTORAL 467 - B.P. 69
13321 MARSEILLE
France

Total cost