Rovins Nano: a cost-efficient and compact INS for flexible subsea operations

iXblue, a global leader in the design and manufacturing of state-of-the-art navigation and subsea positioning solutions, is constantly striving to think of new innovative systems and develops cutting-edge technologies to meet its customers’ ever evolving demanding requirements in terms of operations efficiency.

The company has thus developed a complete range of field-proven subsea inertial navigation products that are recognized for their reliability and unrivaled performance and that offer a very flexible solution, suited for a wide range of subsea operations. The entry level product in iXblue complete range of inertial navigation products is Rovins Nano. Dedicated to ROV navigation, it offers attitude stability, provides accurate positioning of the ROV (with a drift of 0.2% of the travelled distance) and can go to depths reaching 4,000 meters. With a heading accuracy of 0.15 degree secant latitude, iXblue’s Rovins Nano offers a competitive advantage to its users with an entry class focus.

Compact and light-weight, Rovins Nano saves precious space onto ROVs that can then accommodate multiple heavy ROV tooling. ROVs can thus conduct various operations without having to be recovered on deck between each task, saving precious vessel time and allowing for more responsiveness and flexible subsea operations that lead to important productivity and costs reduction.

iXblue Rovins Nano has thus lately been chosen by the University of Limerick’s Centre for Robotics & Intelligent Systems (CRIS) for the development of a new INS based navigation & control suite, OceanRINGS. Part of a larger institution known as MaREI, CRIS aims to research the use of smart automated ROVs for challenging marine applications.

“We have experience using iXblue’s Phins for many years on our larger Observation class vehicle ROV Latis and this INS, coupled with the development of our OceanRINGS control suite, gives us our full 6 degree of freedom precision navigation and DP sub-sea with thruster fault tolerance and accommodation. For our newest smaller ROV Áed we have chosen Rovins Nano as a smaller, more compact precision navigation system ideal for our precision flight control needs.” explains Prof Daniel Toal, Director of CRIS.

iXblue Rovins Nano is used by CRIS as part of the vehicle control system to provide some of the most advanced dynamic positioning capabilities available today. By current practice, ROVs are flown using camera (and sonar) feedback from scene to pilots for remote manual control with simple track-line displays. There is little automatic control and ROV operations are dependent on highly skilled pilots in areas affected by significant disturbances from currents or waves.

Moving to higher levels of ROVs autonomy will enable faster response time to disturbances, as well as higher accuracy in navigation and control over that of a manual pilot. This will, in turn, allow for safer operations in higher sea and tidal states while also extending operational weather windows.

This is why the CRIS teams, who have been focused on ROVs automation, have recently developed a 300msw survey-class ROV, known as Áed, which operational capacity has already been proven thanks to successful trials in wave & tidal test tanks in MaREI, as well as low sea states. CRIS also trialled a Thruster Fault-tolerant system which, using the onboard INS system, monitors errors in course and heading to detect thruster faults.

The Áed ROV was designed with a focus on thrust-to-drag ratios, using CFD analysis of frame and thruster control optimization to allow for high-fidelity and stability.” Explains Dr Gerard Dooly, Research Fellow at CRIS. “The navigation suite was one of the most critical factors and the use of iXblue Rovins Nano, coupled to a Nortek DVL, allowed us to achieve high precision subsea navigation without having to compromise on the weight and size of the vehicle due to navigation payload.

iXblue’s Rovins Nano, compatible with both iXblue and third-party acoustic positioning products offers customers operating on the challenging offshore market with a versatile and cost-efficient inertial navigation solution that can be suited for any subsea operation. User-friendly, it offers valuable time savings in terms of configuration, installation and operational use and provides flexibility and efficiency for successful subsea operations.