HAEGSTAD JON ANDERS (NO)
BJOERNSEN GEIR INGAR (NO)
HASLE MARTIN (NO)
HARHOLT PETER HAVDAL (NO)
HAEGSTAD JON ANDERS (NO)
BJOERNSEN GEIR INGAR (NO)
HASLE MARTIN (NO)
| EP1905688A2 | 2008-04-02 | |||
| GB2211226A | 1989-06-28 | |||
| US4043134A | 1977-08-23 | |||
| US4690587A | 1987-09-01 |
| Claims 1. System for maintenance and inspection of structures located in hard to reach places, using a access frame for positioning of a manipulator arm c h a r a c t e r i z e d b y that said frame consists of: arrangement for fixing said access frame to the mooring chains, said access frame consists of at least one guiding device, said access frame consists of at least one mechanical stabilization function, said remote access frame has the ability to change working equipment, said access frame has a camera, said access frame has a cantilever beam, said access frame is controlled from a control centre. 2. System for maintenance and inspection of structures according to claim 1, c h a r a c t e r i z e d b y that said arrangement for fixing said frame to mooring chain consists of at least one fixing point. 3. System for maintenance and inspection of structures according to preceding claims, c h a r a c t e r i z e d b y that said arrangement for fixing said access frame to the mooring chain may have at least one support beam and that said support beam can have adjustable length. 4. System for maintenance and inspection of structures according to preceding claims, c h a r a c t e r i z e d b y that said at least one support beam can have an adjustable angle . 5. System for maintenance and inspection of structures according to claim 1, c h a r a c t e r i z e d b y that s said frame consists of at least one guiding device. 6. System for maintenance and inspection of structures according to claim 1, c h a r a c t e r i z e d b y that said cantilever beam can have adjustable length. 7. System for maintenance and inspection of structureso according to claim 1, c h a r a c t e r i z e d b y that said access frame can change working equipment for performing both maintenance and inspection task. 8. System for maintenance and inspection of structures according to claim 1, c h a r a c t e r i z e d b y thats said camera connection is a CCTV connection, with possibilities for illuminating the workspace. 9. System for maintenance and inspection of structures according to claim 1, c h a r a c t e r i z e d b y that said control centre controls the movement of the 0 manipulator arm. 10. System for maintenance and inspection of structures according to claim 9, c h a r a c t e r i z e d b y that said control centre provides the access frame with power for operation. 5 |
Technical field:
This invention regards an apparatus for splash zone operations and more particularly to a multi purpose device for positioning of a robotic arm for maintenance and inspection of hard to reach places on an offshore installation like an ocean rig or a vessel. More particularly the device is intended to use mooring chains as a guide.
Background:
Offshore installations are on a daily basis exposed to some of the worst weather conditions in the world. Because of the harsh weather conditions, the need for inspections and maintenance work on these installations are a continually ongoing task. In today's situation the maintenance work is done either by personnel or ROVs, but because of the heavy weather restrictions concerning the protection of personnel and equipment the amount of tasks that can be done in certain areas on the installation is very limited. This means that maintenance and inspection in these areas is very hard and the need for work here is very high.
One of these areas is the splash zone, the splash zone is the zone from sea level and down to where the wave loads is a substantial factor.
For floating and jack up installations it is possible to take them to dock to do maintenance, this is, however, extremely expensive due to lost production and the cost of moving the installation.
All these methods are expensive, dangerous and limited due to the cost of men and machines. This means that today there are no alternatives for maintenance and inspection in the splash zone that are safe for personnel and at the same time reduces the cost and the time consumed.
Summary
An object of the present invention is to solve the problems mentioned earlier and other limitations of the conventional solutions for maintenance and inspection of offshore installations.
The invention described in the independent claims and the thereto dependent claims, describe a mechanical access frame designed to use the mooring chains as a guiding device. The guiding device may be, but is not limited to, wire ropes, chains or fixed steel structures.
On the mechanical access frame it is mounted a changeable manipulator arms capable of performing different kind of operations. The fact that it is changeable means that it can either have a mechanical unit on the end for performing maintenance operations like, grinding, cutting and drilling, etc. It also makes it capable of performing advanced inspection work by placing inspection equipment at the end that includes but is in no way limited to, equipment for visual inspection, x-ray- and eddy current equipment .
The mechanical frame is designed to penetrate the sea surface so that the manipulator arm reaches all places within the range of the manipulator arm.
Vertical positioning of the access frame along the mooring chain is preformed with the use of advanced rigging equipment. For stabilization of the access frame the frame is mechanically fixed to the mooring chains. Further the access frame and the manipulator arm include a CCTV system for full video surveillance of the working operation so that all the operations can be done remotely. The CCTV system is also equipped with lights for illumination of the working space during night operations or operations under water.
The system has a control centre located on top of the offshore installation where personnel can perform the required tasks free from any danger and without any regards to the weather. This control centre has the complete control and manipulation of the system via screens and controls and a computer control unit to remotely operate the equipment. This control centre is also where the arm gets power for movement and the performance of all the equipment .
The installation of the equipment can be based on e.g. advanced rigging and rope access techniques or other kinds of portable equipment for fixing the access frame to the mooring chain. This means that the fixing of the frame does not relay on the permanent lifting equipment found on the offshore installation. This gives it a unique flexibility that gives it the opportunity to be operable regardless of other equipment that may be found on the installation.
Description of the drawings
Figure 1 shows an embodiment of the invention in operation, mounted on the mooring chains [4] on an offshore installation. The access frame is stabilized by two guiding devices [1] connected by a telescopic arm [2] . The telescopic arm stabilizes the access frame at the operation area. The manipulator arm [3] is mounted on to a cantilever beam [5] , which may be rotated relatively to the access frame for positioning of the manipulator arm. Figure 2 shows a detailed view of the guiding device. A wire rope [6] is used for vertical positioning of the guiding device. The guiding device is equipped with a door [7] for mounting on to the mooring chains.