Visualisation, simulation and remote control technologies are now playing a bigger part in the installation, inspection and maintenance of subsea and sea floor equipment. Simon Marr reports.
Remotely operated vehicles (ROVs) equipped with video cameras, positioning and imaging sensors and intervention tooling are now routinely used to inspect and repair subsea pipelines and structures at depths where divers cannot operate. Piloting a valuable ROV in close proximity to subsea assets requires considerable skill to complete missions without problems. Fugro's DeepWorks ROV pilot training and mission planning simulator, uses real-time dynamic and hydrodynamic modelling of the actual vehicle systems to give operators a highly realistic subsea operations training environment.
Fugro Robotic Technologies' principal product range is called DeepWorks and is licensed to satisfy different customer needs. It can be used as an ROV trainer, as an engineering simulator and as a live operations visualisation and monitoring tool.
The DeepWorks ROV pilot training simulator incorporates physical, hydraulic and electrical component libraries that allow Fugro to quickly build up the actual characteristics of the customer's vehicle, sub-systems and tooling.[Page Break]
DeepWorks brings fully force-modelled physics-based simulation to subsea and ROV operations, so that all bodies in the virtual world interact and respond to forces, collisions and environmental conditions in the same way they would in the real world.
Normally integrated with a real console, the pilot gains familiarity through interactive feedback in much the same way they would when navigating the real vehicle or using one of its power tools.
DeepWorks also interconnects with cables, tethers, vessels and other operational components all of which can be controlled, driven, and winched in realistic fashion. High fidelity 3-D graphics rendering is provided with fine control of environmental parameters and sonar data representation. The resulting information is true to life and provides 3-D graphical recording of tailored training tasks or real mission rehearsals based on true physics-based outcomes.
Pilot training must give an objective measure of key pilot competencies to satisfy IMCA guidelines for performing specific tasks, using realistic operator controls and user interface under different degrees of operational difficulty.
DeepWorks enables trainers to measure performance by monitoring the time taken to complete a task, smoothness of control and deviations from planned routes, and forces on and pay-out of the tether, all under various sea conditions. DeepWorks also allows trainers to temporarily 'break' circuits or components to test how well pilots detect and respond to failures. It is important that pilots are able to make the right call when determining if a mission can still be completed safely when ROV systems are compromised or a worsening sea state is encountered.[Page Break]
A common requirement is to turn clients' subsea field and site engineering drawings into 3D models for fly-through demonstrations in the simulator. To automate the process, DeepWorks offers a plug-in to Autodesk 3ds Max that allows third party graphics models to be loaded into the simulator's graphics library. The scenario then picks up the new graphic for flying the mission. Fly-throughs have impact early in projects when concepts need to be conveyed effectively and stakeholder buy-in is being sought. They are also a valuable means of communicating with offshore teams, enabling them to become familiar with new equipment and tasks, refine new procedures and improve levels of understanding for more efficient and safe operations.
For concept selection and design feasibility, DeepWorks also offers an engineering variant that runs on the desktop. By dragging and dropping components from pre-defined libraries, engineers can rapidly prototype subsea solutions containing vessels, cables, and winches, as well as a wide selection of static, dynamic and velocity controlled bodies. Engineers can also add their own custom components by importing 3D engineering models and defining key properties.
Adding Fugro's real-time monitoring library to DeepWorks Engineer, enables live situational monitoring of topside and subsea activities. DeepWorks Engineer Live accepts input via ship systems including Fugro Starfix Message Manager, and processes NMEA standard inputs such as GPS from the vessel, Gyro and USBL data from the ROV or transponders fixed to cables. Vessel, ROV and cable positions are then updated and displayed in real-time. Often turbidity or poor sight lines means cameras are ineffectual. Offering management and operations teams a clear window of the entire field with their own choice of viewpoints enables them to see what they want and make better decisions as real operations unfold.
As a service, Fugro also uses DeepWorks to speed up deployment evaluation of new ROV deployed tooling solutions. As commercial pressures squeeze design time, the sooner simulation is involved the faster and cheaper it becomes to change ROV and tool designs prior to manufacture. This reduces reliance on expensive and time consuming prototypes and wet trials. Full hydraulic and electrical circuit modelling combined with a suite of actuators and manipulators, means virtually any ROV or tool can be created and tested in realistic scenarios.[Page Break]
Monitoring the structural integrity of offshore platforms is time consuming and expensive. Fugro regularly assists customers in the design and development of ROV deployable tools for non-destructive testing of the condition of subsea structures.
TWI in Cambridge developed a prototype Long Range Ultrasonic Tool (LRUT) designed to be deployed by ROV and clamp around vertical or horizontal jacket tubular members. Robotic Technologies created a simulation of the tool deployment by ROV and simulated the tool being aligned and attached to the members. DeepWorks was used to model the actuator mechanisms which controlled the tilt angle and rotation of the tool as well as the operation of the jaw which closes around tubular members. DeepWorks' ease of use allowed TWI's LRUT models to be rapidly imported and configured and early simulations were possible within a day.
Simon Marr is Robotic Technologies Business Development Manager with Fugro Subsea Services Ltd, Aberdeen, UK. www.fugro-rovtech.co.uk