Handling loads at sea
There is an increasing push in the marine and offshore sector to better utilise assets, whatever the weather conditions. Nowhere is this more critical than when lifting, lowering and accurately positioning or transferring loads, equipment and machinery either above the sea or beneath the surface.
Although these loads are generally large and heavy, they are relatively fragile and easily damaged, requiring delicate and precise handling and positioning. This is especially important when landing or interfacing loads from a moving vessel onto a fixed structure either in air or subsea. Handling such loads with any degree of precision or accuracy is difficult from a lifting device located on a floating vessel, as the motion of that vessel caused by wave excitation is directly transmitted to the load. Other activities, for example launching and recovering subsea vehicles (ROVs) that require docking of the vehicle into a tether management system (TMS) prior to recovery, are dependent upon stable position of the docking head.
As a result, such operations are significantly limited by weather conditions and much operational time is lost as a result. This leads to high cost of downtime, low asset utilisation and operational inefficiencies.
Active heave compensation
For this reason, active heave compensation is now the norm amongst most Tier 1 offshore contractors. It cancels the vessel vertical or heave motion in a single degree of freedom by introducing an equal and opposite vertical motion in the lift path. Such systems are referred to as ‘heave compensation’ and while many of the large operators and equipment manufacturers have access to the technology, many smaller ones do not.
Self-learning motion compensation
X-Wave, an advanced motion compensation system, helps fill this technology gap. Its designer, MJR Power & Automation, is patenting a series of innovations, including adaptive and predictive control strategies that provide self learning capabilities for any active heave compensation and platform stabilisation system. The company is offering to integrate the system within any existing or new winch or crane control system.
Automatic commissioning and self-optimisation
Quite often setting up and tuning an active heave compensation system can be time consuming. X-Wave’s self-learning routines bring automatic commissioning and self-optimisation to the application, thereby ensuring the application comes on line faster than any other system or solution. This massively reduces set up costs.
This means the system automatically learns the process characteristics which dramatically reduces, and in some cases eliminates, commissioning. For instance it can learn the machine limitations in acceleration due to power restrictions or high inertia as well as learn fixed actuator delays, such as hydraulic valve or flow response lags caused by pumps and pipework. It can also predict sea motions including pitch, roll or heave.
The system adapts immediately should it experience load changes or suffer from aging, equipment failure, changes in friction, power supply characteristics or poor hydraulic valve response.
X-Wave automatically modifies and optimises control system behaviour in response to changing vessel dynamics. This means no vessel specific setup is required and the equipment can be transferred between vessels offering significant advantages to deployment of portable equipment.The advanced motion compensation system is designed by
MJR Power & Automation and features a range of automation, electrical and control equipment from ABB.
|Real Time Controller||HMI/SCADA||MRU|
|Power||Power Consumption||35 W||22 W||2 W|
|Voltage Requirement||6..35 VDC||24 VDC||12..30 VDC|
|Environmental||Operating temperature||-20°C to 55°C||-10°C to 55°C||-10°C to 65°C|
|Storage temperature||-40°C to 85°C||-20°C to 70°C||-40°C to 65°C|
|Operating humidity||10% to 90% RH, noncondensing||5% to 85% non-condensed||10% to 90% RH, noncondensing|
|Storage humidity||10% to 95% RH, noncondensing||10% to 95% RH, noncondensing||Sealed No limit|
|IP Protection||IP 40||IP 66||IP 64
IP 68 Optional
|Vibration||IEC 60068-2-64||IEC 60068-2-64||
|Accuracy||Angle Accuracy||N.A.||N.A.||0.02° RMS|
|Electromagnetic Compatibility||Electromagnetic Compatibility||EN 61326 (IEC 61326):
Class A emissions;
|EMC Directive 2004/108/EC +
We reserve the right to make technical changes or modify the contents of this document without prior notice. With regard to purchase orders, the agreed particulars shall prevail. ABB does not accept any responsibility whatsoever for potential errors or possible lack of information in this document.
We reserve all rights in this document and in the subject matter and illustrations contained therein. Any reproduction, disclosure to third parties or utilization of its contents – in whole or in parts – is forbidden without prior written consent of ABB.