Page 52: of Marine Technology Magazine (January 2013)

People & Company News Swire Seabed Invests in Custom ROV Launch Kongsberg Evotec will deliver its new mobile Launch and Recovery System (E-LARS) for Remote Operated Vehicle to Swire Seabed in August 2013. Swire Seabed based Near Bergen, Nor- way, has a three-vessel ß eet that pro- vides services across the entire subsea spectrum including construction sup-port, work and observation ROV servic- es and geotechnical, seismic, trenching, dredging, decommissioning and renew- ables support.With its development of E-LARS, Kongsberg Evotec has placed great em- phasis on safety and security for both the operator and equipment. Technical high- lights of the E-LARS system include the use of Permanent Magnet Motor (PM) technology and a low requirement for on-going maintenance.E-LARS uses an innovative control system designed to achieve operational beneÞ ts by providing the operator with continuous real-time information about capacity, and umbilical status and his- tory. E-LARS also features Kongsberg Evotec developed Active Heave Com- pensation that operates on minimal power consumption. As a result of these developments, E-LARS supports opera- tors in extending its operational window. Sonardyne, Oceaneering Demo ROV DP Capabilities A recent trials partnership between Sonardyne International Ltd. and Oceaneering International, Inc. has resulted in the development of a Fly-By-Wire (FBW) system for ROV (Remotely Operated Vehicle) control in any water depth, allowing the vehicle to hold station indeÞ nitely and navigate to real-world coordinates automatically. A Sonardyne SPRINT system was installed on one of OceaneeringÕs Maxximum ROVs and integrated with a Sonardyne Ranger 2 Ultra Short Baseline (USBL) system for acoustic aiding of the Inertial Navigation System (INS). The trials took place in the Gulf of Mexico in water depths of 3,057 m (10,030 ft.) and results showed that continuous hovering of the ROV in mid-water beyond Doppler Velocity Log (DVL) range was possible, as well as automatic navigation to waypoints. The majority of ROV navigation systems use an Attitude and Heading Reference System (AHRS) and DVL to provide a relative or dead reckoned position. These systems are subject to time and distance based position errors and only operate close to the seabed, meaning mid-water operations are conducted via manual control so real world or relative coordinates cannot be easily used by the ROV pilot. Sonardyne and Oceaneering have developed a novel navigation and control sys- tem solution using the dual output of INS and AHRS data from SPRINT to provide ROV Dynamic Positioning (DP) in all water depths with capabilities beyond current state-of-the-art, without affecting reliability or ease of use. The system has two methods of ROV control: ÔNavigationÕ and ÔPassthruÕ. In ÔNavigationÕ mode, the ROV control system uses INS positioning optimized for DP with real-world position, velocity and attitude data at high output rates. This speeds up ROV operations by improving vehicle control precision, automating station keeping and delivering FBW capability. ÔNavigationÕ mode is available continuously in all water depths when USBL data is available. If the INS solution should become degraded or is unavailable, the system automatically reverts to ÔPassthruÕ mode. ÔPassthruÕ mode is a dead reck- oned solution using self contained AHRS data that is inher- ently robust and reliable when combined with DVL data. The results of the trial showed that continuous hovering of the ROV in mid-water beyond DVL range was possi- ble, as well as automatic navigation to waypoints. When the ROV was in DVL range of the seabed the ÔNavigationÕ mode performed equally as well as the ÔPassthruÕ mode but with the added beneÞ t of real-world referenced positioning data from the USBL system. The faster update rate (20 Hz, compared to the 5 Hz rate of the DVL) has the potential to reÞ ne vehicle control precision. www.Sonardyne.com www.Sonardyne.com L to R: Jon Olav Kopperstad, VP Offshore Supply & Subsea, DagÞ nn Vattøy, Sales Manag- er, Leif Løken, Product Man- ager. January/February 2013 52 MTRMTR #1 (50-64).indd 52MTR #1 (50-64).indd 521/30/2013 11:30:16 AM1/30/2013 11:30:16 AM