The Thinking ROV
14 April 2011
Engineers at Saab Seaeye have created a vital new development in ROV architecture.
Called ‘The Intelligent Control of Nodes' (ICON), the concept allows each device within the ROV to think for itself and talk remotely to operators and engineers through a gateway into the heart of the vehicle.
It gives users remote access to diagnostics, software upgrades and system inventory directly on board the ROV, via an enabled web interface, from anywhere in the world.
ICON makes this possible by enabling each microprocessor (node) to operate as a sensor and report its unique status to the central control system.
This kind of self-management of the ROV makes it better able to cope with its hostile environment and accommodate breakdown and damage and stay working for as long as possible.
Indeed a core objective of ICON is to ensure the ROV will survive the loss of one or more systems or components.
Improving and simplifying control to deal with problems as well as day to day tasks is part of the ICON philosophy. Previously, ROV systems have needed the operator to make various assumptions about the state of the ROV under command, whereas ICON now gives precise feedback.
As a complete system, it allows communication across three modes: operational, diagnostic and update.
In the case of a thruster, for example, the operational mode controls, start, stop, speed and direction; the diagnostic mode gives a health check and allows interrogation of parameters such as power, temperature, hours run and vibration; and the update mode allows new control software to be downloaded to the thruster when updates are available and new features are introduced.
To add or enhance equipment on board is now easier because interfaces have been standardised into a common unambiguous format.
This also means that development and de-bugging tools built around the ICON concept will speed the introduction of new systems and their successful integration.
Keeping the ROV working in its harsh and hostile environment where things can go wrong is a vital feature of ICON.
Not only will it generate an alert to a system failure, but will predict it. This comes because data provided by ICON is both active and historical and therefore capable of arriving at a dynamically analytical conclusion.
For instance, should a thruster get entangled, it instantly recognises it has a load problem and shuts itself down. At the same time it alerts the rest of the system so that the remaining thrusters can automatically compensate for the loss of the compromised thruster and keep the ROV under control.Before ICON, the first warning a pilot would have is when the ROV starts going round in circles and he is battling for control. Not realising that one thruster is entangled, his natural inclination is to keep boosting power, unaware of the potential damage being done to the thruster.
With ICON overcoming the problem, the pilot is spared the fight for control and can concentrate on completing the task in hand, before retrieving the ROV.
With each device constantly sensing its state of health and instantly reporting back problems, the operator not only has greater control, but their role is made much easier and simpler.
And whilst ICON makes it more likely the ROV will survive the loss of one or more system, it tells the operator when to keep going, and when to bring the vehicle home.
The ROV is more likely to stay healthy with ICON at its core as usage hours on components are tracked, and problems that might be brewing are highlighted. It also predicts when and if a device will fail and alert maintenance crew before a problem occurs.For instance by recording the rotation time of each thruster, usage data is 100% accurate when compared to the dive log that simply records the time the ROV spends in the water. Such consistent and detailed analysis of each device not only generates a preventive maintenance alert, but also gives true preventive maintenance information, such as the actual individual thruster rotation time and its consequent oil change needs.
Essentially, with each device constantly monitoring and reporting its status, and problems instantly identified, operators are better able to keep a vehicle in operation than would otherwise be possible.
For spares management, being able to remotely examine systems within the ROV allows the operator/base managers to accurately monitor both equipment and spares inventory through accessing part numbers and serial numbers on the ROV.
The ICON concept, and its capability for remote interrogation, has been made possible using middleware capable of handling huge data volumes, along with sophisticated auto onboard diagnostic systems, and creating a system that would allow the management of large amounts of data within an ROV in a simple way
It has resulted in a development that is the future for ROV users. It will bring a new level of assured reliability, easier operation, better maintenance management, a lower cost of operation and the ability to develop ever more sophisticated and reliable systems for handling a wider range of tasks.