Subsea inspection vehicle

A subsea vehicle capable of supporting inspection of underwater objects while underway includes a body that provides a capability to allow the subsea vehicle to submerge underwater and follow or position near an object while maintaining an orientation to the object appropriate for inspection of, and safety requirements for, the object. The vehicle includes a set of deployable, semi-rigid arms to support the movement of inspection sensor probes near or lightly touching the inspection target with the probes. A controller helps tracks the intended inspection object using various sensor inputs along with a priori knowledge of the object to drive and position the subsea vehicle such that the appropriate orientation to the inspection target is maintained.

BACKGROUND

Subsea inspection often utilizes manned vehicles or divers to perform the required inspections. However, these have costs and limitations associated with them. Currently, a vessel with a remotely operated vehicle (ROV) has to deploy the ROV down to a subsea structure such as a pipeline and then sail along the pipeline route while the ROV “flies” over the subsea structure while making visual and non-destructive examinations (NDE) of the subsea structure. This is expensive because it requires an entire ship, ship crew, ROV, at ROV crew at day rates which may be in excess of 200,000 USD per day in day rates. It also uses an enormous amount of fuel to sail the entire vessel. Using an automated underwater vehicle (AUV) would be advantageous because it can be dropped off at a platform or other offshore structure and track the structure autonomously, with no requirement for a crew or vessel.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

In a first embodiment, referring generally toFIG.1, subsea vehicle1is used to help support inspection of one or more underwater objects2and navigates and positions itself proximate a desired underwater object2using an autonomous navigation process while underway subsea. Subsea vehicle1typically comprises body10; one or more selectively movable inspection sensor probes20; a set of deployable semi-rigid arms30; arm actuator31(FIG.3) operatively connected to the set of deployable semi-rigid arms30; one or more position sensors40which are adapted to sense a position of inspection sensor probe20relative to body10and disposed at a distal end of deployable semi-rigid arm30; and controller100. As used herein, intended subsea inspection object2may be a subsea pipeline or a subsea tree or the like.

Body10typically comprises one or more propulsion systems11(FIG.3) and navigator12(FIG.3) which is operatively in communication with propulsion system11which may comprise a motor and a propeller, as illustrated inFIG.3.

As illustrated inFIG.2, sensor probes20and deployable semi-rigid arms30may be selectively moved from a position close to body10or as illustrated inFIG.1to a position away from body10such as by using inspection sensor probe actuator21to move its associated sensor probe20and by using arm actuator31to move its associated deployable semi-rigid arm30.

Position sensor40could be any sensor capable of detecting intended subsea inspection object2such as a sonar sensor, a magnetometer, an optical sensor, a lidar sensor, or the like, or a combination thereof.

Controller100is operatively in communication with position sensors40, navigator12, and arm actuators31(FIG.3) and may comprise a microprocessor and associated memory which do not need to be illustrated for one of ordinary skill to understand the claimed invention. Typically, controller100is adapted to track and autonomously navigate to intended subsea inspection object2using data from position sensors40along with a priori knowledge of the intended subsea inspection object2which has been supplied to controller100. Controller100typically issues one or more commands to navigator12to drive and position subsea vehicle1subsea such that an appropriate orientation of subsea vehicle1to the intended subsea inspection object2, and distance between subsea vehicle1and the intended subsea inspection object2, is maintained which is appropriate for inspection of intended subsea inspection object2. The orientation and distance may further be influenced by safety requirements of the intended subsea inspection object2. In certain embodiments, one or more transducers103-105may be present and used to help with position sensors40and/or inspection sensor probes. By way of example and not limitation, transducers103-105may be optical sensors such as still cameras or video cameras, cathodic protection probes, x-ray transducers, ultrasound (UT) sensors, or magnetic flux sensors, or the like, and can be used to perform surveys of subsea inspection object2.

Each deployable semi-rigid arm30is operatively connected to one or more arm actuators31which are adapted to move deployable semi-rigid arm30and its associated position sensor40away from inspection sensor probe20when the inspection sensor probe20is located near the intended subsea inspection object2should the inspection sensor probe20be needed for an inspection process. Arm actuators31are further configured to support an orientation of deployable semi-rigid arms30operatively connected to arm actuators31.

In certain embodiments, inspection data gatherer201is present and operatively in communication with inspection sensor probe20via an interface to inspection sensor probe20. Inspection data gatherer201typically comprises a data processor, e.g. processor and memory and data transceiver illustrated as unit202, to provide data to and receive data from an external data receiver (not shown in the figures). In other embodiments, controller100is operatively in communication with inspection sensor probe20via the interface to inspection sensor probe20.

In certain embodiments, power may be supplied to subsea vehicle1by batteries101which may comprise or otherwise be associated with battery pressure compensators.

In certain embodiments, sensor control bottles102may be present and associated with sensor20.

In the operation of exemplary methods, referring back toFIG.1, subsea vehicle1, which is as described above, may be used to support inspection of underwater objects2by deploying subsea vehicle1using controller100by supplying controller100with spatial knowledge of intended inspection object2useful for autonomous subsea navigation. Once supplied, controller100is used to navigate subsea vehicle1to a position subsea proximate intended inspection object2. In doing so, controller100may issue one or more commands to navigator12such as to submerge subsea vehicle1underwater and/or to autonomously command subsea vehicle1to follow a path subsea defined by a traversal of subsea vehicle1subsea from its current position to intended subsea inspection object2.

Once proximate intended subsea inspection object2, controller100typically initiates a positioning process by issuing one or more commands to navigator12to position the subsea vehicle1near intended subsea inspection object2. Navigator12then selectively controls propulsion system11, which typically comprises a propeller, to maintain a desired orientation of subsea vehicle1with respect to inspection target object2. The positioning process may further comprise controller100issuing one or more commands to deploy position sensor40such as by moving its associated deployable semi-rigid arm30using arm actuator31and gather data representative of a current position subsea of subsea vehicle1relative to inspection target object2from position sensor40. Position sensor40is typically used to detect the position of inspection target object2so subsea vehicle1can stay above inspection target object2while “flying” or “swimming.”

In addition, inspection sensor probe20may be deployed by using its associated arm actuator31to a position suitably located to gather data in support of inspection requirements associated with inspection target object2and data then gathered, e.g. by controller100or inspection data gatherer201. The position subsea of subsea vehicle1relative to inspection target object2may comprise a location where inspection sensor probe20is close to or lightly touching inspection target object2.

Controller100typically then uses the data representative of the current position subsea of subsea vehicle1relative to inspection target object2issue one or more commands to navigator12to maintain the orientation of subsea vehicle1with respect to inspection target object2while inspection data are being gathered.

The foregoing disclosure and description of the inventions are illustrative and explanatory. Various changes in the size, shape, and materials, as well as in the details of the illustrative construction and/or an illustrative method may be made without departing from the spirit of the invention.