INSPECTION VEHICLE

Abstract

Inspection vehicle for under water inspection of coating, marine growth, structural integrity and corrosion on ferromagnetic ship hulls and other ferromagnetic structures. The inspection vehicle is distinctive in that it comprises a non-magnetic element, at least one magnetic wheel or device operatively arranged to the element, and a watertight camera for visual inspection attached to the element or other structure of the inspection vehicle, wherein the inspection vehicle comprises one coupling side where the at least one magnetic wheel or device is operatively arranged for the inspection vehicle to couple magnetically through coating, any marine growth and corrosion products and allow rolling the inspection vehicle on said structure, in horizontal to vertical to upside down-orientation while holding the inspection vehicle attached to the structure, and one non-coupling side oriented in substance in opposite direction to the coupling side, where the at least one magnetic wheel is not operatively arranged and the non-coupling side will not couple magnetically to said structure. A method for operating the inspection vehicle is also provided.

Claims

1. An inspection vehicle for underwater inspection of a ferromagnetic structure, the inspection vehicle comprising: a non-magnetic element; at least one of a magnetic wheel and magnetic device operatively arranged to the non-magnetic element; a watertight camera for visual inspection attached to the non-magnetic element or other structure of the inspection vehicle; a coupling side where at least one of the magnetic wheel and the magnetic device is operatively arranged for the inspection vehicle to couple magnetically in an underwater environment through a coating, any marine growth, and corrosion products and allow rolling of the inspection vehicle on the ferromagnetic structure, in a horizontal to vertical to upside down-orientation while holding the inspection vehicle attached to the ferromagnetic structure, wherein the structure of the at least one of a magnetic wheel and magnetic device is the only structure securing the attachment of the inspection vehicle in position in vertical to upside down orientation; a non-coupling side oriented in substance in opposite direction to the coupling side; a combination of an inductance-based sensor and an ultrasound-based sensor, wherein exact lift-off, that is the combined coating thickness and marine growth thickness, is measured by using the inductance-based sensor only, wherein the inductance-based sensor is configured to measure the lift-off exactly, irrespective of and unaffected by the type of marine growth or the condition of the coating; and, wherein the type of marine growth is found by measuring coating thickness by the ultrasound-based sensor; wherein the properties of the unknown marine growth affect the ultrasound velocity and reflections, but since the exact thickness of the marine growth can be determined by subtracting the coating thickness from the lift off, said affected properties can be correlated to determine the type of marine growth when the thickness of the marine growth is known; a connector end, where a rope or line for lowering and lifting the inspection vehicle, and lines for power and control, are connected, as a bundle or a single line or umbilical, wherein the lowering is controlled by gravity and letting out of the rope or line; at least two axially apart wheels, wherein the axially apart wheels remote from the connector end are larger in at least one of number and weight than wheels near the connector end, providing a center of gravity closer to an end remote from the connector end of the inspection vehicle; and wherein the inspection vehicle weighs less than 25 kg and has no dimension larger than 1 m as packed in an operations container, allowing transport, handling, and operation by one single operator.

2. The inspection vehicle according to claim 1, comprising one or more of the features: wherein the non-magnetic element is at least one of single and double concave; a concave shell structure, beam structure or truss structure having curvature or concavity so that when the inspection vehicle hangs along a vertical ship hull side, the center of gravity is at an elevation below a midpoint between at least two magnetic wheels at differing elevations; a solenoid-operated release mechanism for placing out sensors or other equipment; a light; a wheel with a drive mechanism; a position or motion sensor and associated software arranged to document position and motions at all times during an inspection run, and wherein one or more of corrosion, coating quality, and ferromagnetic structure wall or hull thickness are measured with the ultrasound-based sensor.

3. A method for underwater inspection of a ferromagnetic structure using an inspection vehicle according to claim 1, the method comprising: starting recording with the watertight camera; lowering the inspection vehicle down to the ferromagnetic structure and below the surface, while the inspection vehicle hangs in a rope/cable, by letting out the rope/cable, until a desired depth or position has been reached, whereby the inspection vehicle is held and rolled on the ferromagnetic structure in positions from horizontal to vertical to upside down, wherein the structure of the coupling side attaching the inspection vehicle in vertical to upside down-orientation to the ferromagnetic structure consists of magnetic wheels and magnetic devices, and wherein the lowering is controlled by gravity and a letting out of the rope or cable; wherein a combination of an inductance-based sensor and an ultrasound-based sensor is utilized, wherein lift-off is measured with the inductance-based sensor, while the ultrasound-based sensor, when knowing the lift-off as measured by the inductance-based sensor, measures coating thickness, wherein the properties of the unknown marine growth affect the ultrasound velocity and reflections, but since the exact thickness of the marine growth thereby can be determined, said affected properties can be correlated to determine the type of marine growth; wherein the inspection vehicle weighs less than 25 kg and has no dimension larger than 1 m as packed in an operations container, allowing transport, handling, and operation by one single operator; and repeating the steps above at desired positions for inspection.

4. Method according to claim 3, wherein an arrangement of the axially apart wheels remote from the connector end are larger in at least one of number and weight than wheels near the connector end, providing a center of gravity closer to an end remote from the connector end of the inspection vehicle, wherein stability of tracking of the inspection vehicle is facilitated.

5. The method according to claim 3, comprising adjusting the magnetic coupling force.

6. The method according to claim 3, wherein: the ferromagnetic structure being inspected is at least one of a tank wall thickness, a pipe wall thickness, and a vessel hull thickness, and further parameters measured are at least one of corrosion, coating quality and ferromagnetic structure wall or hull thickness;

7. The inspection vehicle according to claim 1, wherein a concave shell structure, beam structure, or truss structure encompasses the at least one magnetic wheel.

8. An inspection vehicle for underwater inspection of a ferromagnetic structure, the inspection vehicle comprising: a non-magnetic element; at least one of a magnetic wheel and magnetic device operatively arranged to the non-magnetic element; a watertight camera for visual inspection attached to the non-magnetic element or other structure of the inspection vehicle; a coupling side where at least one of the magnetic wheel and the magnetic device is operatively arranged for the inspection vehicle to couple magnetically in an underwater environment through a coating, any marine growth, and corrosion products and allow rolling of the inspection vehicle on the ferromagnetic structure, in a horizontal to vertical to upside down-orientation while holding the inspection vehicle attached to the ferromagnetic structure, wherein the structure of the at least one of a magnetic wheel and magnetic device is the only structure securing the attachment of the inspection vehicle in position in vertical to upside down-orientation; a non-coupling side oriented in substance in opposite direction to the coupling side; a connector end, where a rope or line for lowering and lifting the inspection vehicle, and lines for power and control, are connected, as a bundle or a single line or umbilical, wherein the lowering is controlled by gravity and a letting out of the rope or line; at least two axially apart wheels, wherein the two axially apart wheels remote from the connector end are larger in at least one of number and weight than wheels near the connector end, providing a center of gravity closer to an end remote from the connector end of the inspection vehicle; and wherein the inspection vehicle weighs less than 25 kg and has no dimension larger than 1 m as packed in an operations container, allowing transport, handling, and operation by one single operator.

9. The inspection vehicle according to claim 8, comprising a combination of an inductance-based sensor and an ultrasound-based sensor, wherein lift-off is measured with the inductance-based sensor and coating thickness is measured with the ultrasound-based sensor, and when thereby determining the marine growth thickness, type of marine growth is determined based on differences in ultrasound velocity and reflexes.

10. The inspection vehicle of claim 9, wherein one or more of corrosion, coating quality, and ferromagnetic structure wall or hull thickness are measured with the ultrasound based sensor.

11. An inspection vehicle for underwater inspection of a ferromagnetic structure, the inspection vehicle comprising: a non-magnetic element; at least one of a magnetic wheel and magnetic device operatively arranged to the non-magnetic element; a watertight camera for visual inspection attached to the non-magnetic element or other structure of the inspection vehicle; a coupling side where at least one of the magnetic wheel and the magnetic device is operatively arranged for the inspection vehicle to couple magnetically in an underwater environment through a coating, any marine growth, and corrosion products and allow rolling of the inspection vehicle on the ferromagnetic structure, in a horizontal to vertical to upside down-orientation while holding the inspection vehicle attached to the ferromagnetic structure; a non-coupling side oriented in substance in opposite direction to the coupling side; a combination of an inductance-based sensor and an ultrasound-based sensor, wherein exact lift-off, that is the combined coating thickness and marine growth thickness, is measured with the inductance-based sensor, unaffected by the type of marine growth or the condition of the coating, while the ultrasound-based sensor, when knowing the exact lift-off as measured independently by the inductance-based sensor, measures coating thickness, wherein properties of the unknown type of marine growth can be determined since exact marine growth thickness can be determined by subtracting the coating thickness from the lift off and differences in ultrasound velocity and reflections thereof can be correlated to marine growth type, and, optionally, also measuring one or more of corrosion, coating quality, and ferromagnetic structure wall or hull thickness with the ultrasound sensor; further comprising a connector end, where a rope or line for lowering and lifting the inspection vehicle, and lines for power and control, are connected, as a bundle or a single line or umbilical, wherein the lowering is controlled by gravity and a letting out of the rope or line; at least two axially apart wheels, wherein the two axially apart wheels remote from the connector end are larger in at least one of number and weight than wheels near the connector end, providing a center of gravity closer to an end remote from the connector end of the inspection vehicle; and wherein the inspection vehicle weighs less than 25 kg and has no dimension larger than 1 m as packed in an operations container, allowing transport, handling, and operation by one single operator.

Description

FIGURE

[0067] The inspection vehicle of the invention is illustrated by 7 figures, namely

[0068] FIGS. 1A and 1B, illustrating one of many possible embodiments of an inspection vehicle of the invention, as seen from the side and from above, respectively,

[0069] FIG. 2 illustrating another embodiment of the inspection vehicle of the invention,

[0070] FIG. 3 illustrating a further embodiment of an inspection vehicle of the invention, as hanging down a ship hull side,

[0071] FIGS. 4 and 5 illustrate an embodiment of magnetic wheels, and

[0072] FIGS. 6 and 7 illustrate an embodiment of magnetic devices.

DETAILED DESCRIPTION

[0073] Reference is made to FIGS. 1A and 1B, illustrating an inspection vehicle of the invention, as seen from the side and from above, respectively. More specifically, the inspection vehicle (1) for under water inspection of coating, marine growth, structural integrity and corrosion on ferromagnetic ship hulls and other ferromagnetic structures, above and below water comprises a non-magnetic element (2), at least one magnetic wheel (3) operatively arranged to the element, and a watertight camera (4) for visual inspection attached to the element or other structure of the inspection vehicle. The inspection vehicle further comprises one coupling side (5) where the at least one magnetic wheel is operatively arranged for the inspection vehicle to couple magnetically and allow rolling the inspection vehicle on said structure, through coating, marine growth and corrosion, in horizontal to vertical to upside down-orientation while holding the inspection vehicle attached to the structure; and one non-coupling side (6) oriented in substance in opposite direction to the coupling side, where the at least one magnetic wheel is not operatively arranged and the non-coupling side will not couple magnetically to said structure. The inspection vehicle also comprises sensors 7,8 and means 9 for placing out and retrieving sensors or other equipment, position or motion sensor 10, GPS sensor 11, light 12, for example a LED light rail, and a rope 13 for combined handling/lowering, power, control and communication.

[0074] FIG. 2 illustrates a further embodiment of an inspection vehicle 1 of the invention, wherein the non-magnetic element 2 is a concave beam structure. In a lower end, as seen when hanging down a ship hull side, two magnetic wheels 3 are laterally protected from attaching to the structure to be inspected by structure 2L of the non-magnetic element 2. The concavity or curvature of the non-magnetic element is “inclined downwards”, which provides a center of gravity closer to the lower end than the upper end when the inspection vehicle hangs from a rope 13 in the upper end. The height of the illustrated inspection vehicle is not to scale but is exaggerated, to see the details thereof clearer. In the upper end a magnetic wheel 3 is arranged in between non-magnetic wheels 14, preventing lateral coupling by the magnetic wheel 3 in between.

[0075] FIG. 3 illustrates a further embodiment of the inspection vehicle 1 and the method of the invention. More specifically, the further inspection vehicle 1 embodiment comprises a shell-like concave structure as non-magnetic element 2 and the inspection vehicle is illustrated as rolling down a ship hull side 15, lowered with a rope or line 13, helped by gravity g. A drive mechanism 16, and optionally a steering mechanism 17, can be included, and will help in deploying the inspection vehicle further under the hull towards and optionally beyond the keel. A magnetic device 3m is illustrated.

[0076] FIGS. 4 and 5 illustrate an embodiment of magnetic wheels, more specifically as seen from the side and from a front position. Pieces of permanent magnets are arranged regularly along the periphery of otherwise non-magnetic wheels. The permanent magnet pieces extend as far out in radial direction of the wheel as non-magnetic parts, which improves wear resistance. Alternatively, the magnetic pieces extend 0-3 mm less in radial direction than the non-magnetic parts of the wheel.

[0077] FIGS. 6 and 7 illustrate an embodiment of magnetic devices, as seen from the side and from a front position. The magnetic devices are preferably non-rotatable permanent magnet pieces, they are easy to take in our out for adjusting magnetic coupling force or cleaning for any magnetic debris. Magnetic coupling force is adjusted by adjusting the number and/or type of magnetic devices used in the inspection vehicle.

[0078] Double magnet wheels, or even triple magnet wheels, and/or magnetic wheels with adjustable magnetic coupling force, can be used if increased magnetic coupling is required.

[0079] The invention provides an inspection vehicle for under water inspection of ship hulls and other ferromagnetic structures, but also non-ferromagnetic structures that are orientated upwards from gravity, allowing inspection even without magnetic coupling.

[0080] The inspection vehicle is distinctive in that it merely may consists of a non-magnetic element, at least one magnetic wheel arranged operatively to said element, and a watertight camera for visual inspection of coating, marine growth, structural integrity and corrosion of the structure being inspected, in addition to optional sensors and light. The inspection vehicle has a size and weight making it easy for one person to operate and transport the inspection vehicle. Said non-magnetic element is preferably convex or double convex, at an extent making it impossible for the inspection vehicle of the invention to attach itself to a ship hull or other ferromagnetic structure to be inspected when at upside-down orientation or sideways orientation relative to the hull or structure to be inspected. In contrast to the comprehensive prior art systems, requiring a team of personnel and typically a container full of equipment, only one or two persons are required for operation.

[0081] The inspection vehicle of the invention and the method of the invention provide an easier and more cost effective way of deciding inter alia the existence and extent of marine growth on a hull, and whether or not to remove said growth. One person can operate the inspection vehicle when a ship is at a harbor in ordinary operation. The invention has a significant positive effect on the environment, since convenient removal of marine growth reduces fuel consumption of ships significantly.

[0082] The inspection vehicle of the invention can have numerous embodiments, including any combination of features here described or illustrated. The method of the invention can include any feature or step as here described or illustrated, in any operative combination.