WO2011033292A1

WO2011033292A1 - Non-permanently tethered communication between an autonomous underwater vehicle and a base station

Info

Publication number: WO2011033292A1
Application number: PCT/GB2010/051535
Authority: WO
Inventors: Andrew Tonge
Original assignee: Bae Systems Plc
Priority date: 2009-09-15
Filing date: 2010-09-14
Publication date: 2011-03-24

Abstract

An autonomous underwater vehicle comprising a body portion may be provided. A processing device is mounted within the body portion and one or more sensors are mounted on or within in the body portion. Data output means configured to enable connection of the processing device to a physical data carrier during operation of the vehicle are provided.

Description

NON-PERMANENTLY TETHERED COMMUNICATION BETWEEN AN AUTONOMOUS UNDERWATER VEHICLE AND A BASE STATION

The present invention relates to an autonomous underwater vehicle, in particular a vehicle able to be operated in a supervised mode on an occasional basis.

Remotely operated vehicles (ROVs) are known (see Figure 1 ) and, in the maritime field, fall into one of three categories. A tethered system (Figure 1 a) represents a waterborne piece of equipment 2 (ROVI), permanently tethered by a cable 4 to a base station located either at a parent vehicle 6 or, as shown here, at a garage 8 located on or near the sea bed 10. Power and data are transferred between the ROVI 2 and the base station along cable 4 to enable permanent communication therebetween. The garage 8 is provided with power and a data transfer facility via a heavy cable 12 sourced from either a parent vehicle or from a mainland facility (not shown).

In a second category, a ROVII may be represented by a free-swimming, unmanned, underwater vehicle (UUV) 14 as shown in Figure 1 b. The UUV 14 represents stand alone apparatus, configured to sense features in a local environment 16 and make assessments and decisions based on the output from in built or deployable sensors (not shown) in combination with a predetermined mission received prior to launch of the vehicle 14.

Some torpedoes 18 fall into a third category of remotely operated vehicle

(ROVIII) illustrated in Figure 1 c. ROVIII 18 comprises one or more guide wires 20, e.g. a copper wire or, more recently, fibre optic cables. The guide wires 20 play out as the ROVIII 18 is deployed. The guide wires 20 serve to enable two way, data only, communication between an operator (not shown) and the ROVIII 18. The operator typically drives the ROVIII 18 in a driven mode for part of its journey and then switches the ROVIII into a homing mode for completion of the journey/mission.

According to a first aspect, the present invention provides an autonomous underwater vehicle comprising:

a body portion;

a processing device mounted within the body portion; a sensor mounted on or within in the body portion; and data output means configured to enable connection of the processing device to a physical data carrier during operation of the vehicle.

By providing an autonomous underwater vehicle with an ability to be connected to a physical data carrier during operation of the vehicle, the functionality of the vehicle is enhanced. The autonomous vehicle can be used in a supervised mode to enable real time access to data collected by the vehicle. An operator located at the other end of the physical data carrier is able to monitor and interrogate the vehicle and, subsequently, transmit alternative or more detailed instructions to the vehicle to change a mission strategy even during the mission itself.

The vehicle may be provided in combination with a data carrier, wherein the data carrier comprises dispensing means for dispensing a length of data transfer cable.

The data carrier may comprise one of the group of severing means, releasing means and retracting means for separating the data transfer cable from the vehicle or stowing the data transfer cable after use. The data transfer cable may be a fibre optic cable.

The dispensing means may comprise a spool assembly. The spool assembly may be configured to be neutrally buoyant. The spool assembly may comprise a sub-assembly associated with a base station from which the vehicle is launched and/or the spool assembly may comprise a sub-assembly associated with and mounted on the vehicle.

According to a second aspect the present invention provides a data carrier, comprising dispensing means for dispensing a length of cable and a releasable connection means for connecting the data carrier to an autonomous underwater vehicle.

The releasable connection means may comprise an electromechanical release mechanism which may, in turn comprise a latching mechanism. The connection means may be configured to be released from the vehicle upon receipt of an instruction from a base station from which the vehicle was launched, alternatively the connection means may be configured to be released upon a detected behaviour of the vehicle, for example if a data connection with the base station was lost.

According to a third aspect the present invention provides a method of operation of an unmanned underwater vehicle (UUV) comprising the steps of: determining a mode of operation of the vehicle, dependent on mission criteria;

supplying instructions to the vehicle;

launching vehicle from a base station;

if the determined mode of operation is a supervised mode, dispensing a data transfer cable connected between the vehicle and the base station; collecting data from sensors located on board the vehicle; and

returning data from the vehicle to the base station via the cable.

The dispensing step may comprise attaching a distal end of the data transfer cable to the vehicle and dispensing a length of data transfer cable from the base station. Alternatively, the dispensing step may comprise substantially simultaneously dispensing a first portion of the data transfer cable connected to the vehicle and a second portion of the data transfer cable connected to a base station from which the vehicle is launched.

The method may comprise the steps of analysing data collected by the UUV and returning a sub-set of the collected data to the base station.

The method may comprise the steps of determining whether changes in the supplied instructions are required, dependent on the returned data and transmitting any such changes to the UUV, via the data transfer cable.

The method may comprise the steps of separating the vehicle from the base station and continuing operation of the vehicle in an autonomous mode.

The present invention is now described in more detail, with reference to the accompanying drawings, in which: Figure 1 illustrates three different types of remotely operated vehicles;

Figure 2 illustrates a first embodiment of an occasionally tethered UUV;

Figure 3 illustrates a second embodiment of an occasionally tethered UUV; and

Figure 4 illustrates a data carrier in more detail.

A conventional UUV 14 (illustrated in Figure 1 b) relies on its autonomy to achieve a freedom of movement to enable comprehensive use of its sophisticated design. However, circumstances may arise whereby it is beneficial to operate the UUV 14 in a supervised mode. Such a mode can be achieved as illustrated in Figures 2 and 3 whereby data collected by the UUV may be monitored by and/or passed back to an operator (not shown) for further analysis and/or assessment. Consequently, decision making can be undertaken by the operator and high level mission changes can be considered. Instructions to implement these changes can then be returned to the vehicle for exploitation.

Figures 2 and 3 each represent an unmanned underwater vehicle (UUV) 32 , 52 each configured to pass through a body of water and collect data from the underwater environment via one or more on-board or deployable sensing devices (not shown). Each UUV 32, 52 is able to operate in a fully autonomous mode in isolation or (as illustrated) each UUV 32, 52 may be tethered to a respective base station 34, 52 (e.g. a parent vehicle located at a surface of the body of water) via a data transfer cable mechanism 36, 46 to effect a supervised mode as indicated above.

In Figure 2 the data transfer cable mechanism 36 comprises a spool assembly 38 located at the base station 34, configured to deploy a robust cable 40. The cable 40 is preferably a fibre optic cable having a diameter in the range of 1 to 5 mm, preferably approximately 2 mm. As the diameter of the cable 40 is substantial it will have a large bend radius and so the spool assembly 38 used to dispense the cable 40 is correspondingly large. Consequently, the spool assembly 38 is locate at the base station 34 as its presence at the vehicle 32 would disrupt the trim of the vehicle 32. A proximal portion of the cable 40 is permanently connected to the spool assembly whilst a distal end of the cable 40 comprises a plug 42. A socket 44 is provided at a rearmost portion of the vehicle 32 and is configured to receive the plug 42 in a releasable manner.

Figure 3 illustrates a similar embodiment to that described in relation to

Figure 2 whereby a data transfer cable mechanism 46 comprises first and second spool assemblies 48, 50 separated from one another. The first spool assembly 48 is located at a base station 54 and the second spool assembly 50 is mounted on a UUV 52 e.g. at a rearmost upper portion thereof as illustrated. A data cable 56, e.g. a fibre optic cable, extends from the first spool assembly 48 to the second spool assembly 50. In this embodiment a fine cable 56 is provided having a diameter of less than 1 mm, preferably approximately 0.25 mm. This cable 56 is more delicate and is hence deployed from both a proximal end and a distal end to avoid exposure of the cable 56 to excessive tension which may cause breakage thereof. The length of cable 56 is preferably up to approximately 3 km but may readily exceed this and be in a range up to 10 or 20 km. Thus a significant body of water can be explored even in the supervised mode.

The cable 56 is considered to be expendable and would, therefore, not be intended to be recovered by said first and second spool assemblies 48, 50. Consequently, the second spool assembly 50 in particular can be less sophisticated and, therefore, lighter. Preferably, the second spool assembly 50 is neutrally buoyant so that any effect on trim of the vehicle 52 is minimised.

The second spool assembly 50 may be referred to as an independent data carrier and is illustrated in Figure 4. A latching mechanism 58 may be connected to the vehicle and is configured to receive the spool assembly 50 and secure the assembly to the vehicle during operation. The latching mechanism 58 may be provided by an electromechanical device able to receive instructions from the operator. Alternatively, a sensor may be provided to detect some behaviour of the vehicle, e.g. the speed of the vehicle or loss of a data connection between the vehicle 52 and the base station 54. In operation, prior to commencennent of a particular mission, it is established whether the UUV 32, 52 ought to be deployed in a normal, free swimming, autonomous mode or whether it would be beneficial to directly exchange data with the UUV for at least part of the mission and hence be deployed in a supervised mode. A supervised mode might be employed to achieve an oversight role or to enable verification and validation of the mission potentially leading to high level mission changes during the mission.

In the former instance, the UUV 32, 52 is launched from the base station 34, 54 without activating the data transfer cable mechanism 36, 46. In the latter instance, the UUV is deployed in a tethered, supervised mode as described below.

In the first embodiment, the plug 42, located at the distal end of the cable 40, is coupled with the socket 44, mounted on the vehicle 32 and the vehicle itself is launched from the base station 34. The cable 40 is dispensed from the spool assembly 38 as the vehicle 32 is deployed. The cable 40 is intended to be recoverable and is, therefore, more robust than that used in the second embodiment. The combined cable length is correspondingly shorter, say 100m to 500m, preferably approximately 300m.

In the second embodiment, the UUV 52 is launched from the base station 54 and the data cable 56 is dispensed at either end thereof by the first and second spool assemblies 48, 50 substantially simultaneously. As the cable 56 is deployed at either end thereof, it experiences very little or no tension and can, therefore, be quite light and fine without being broken, as discussed above.

In the supervised mode, the UUV 32, 52 is left to perform in a substantially autonomous manner but active monitoring of the data can be accomplished so that high level change can be initiated by the operator if appropriate. A substantial quantity of data is able to be collected by the UUV 32, 52. Processing may be undertaken by the UUV in order to restrict the data to be passed along the data cable 40, 56 to the operator. The operator may be a human operator or may be a computer, depending on the type of analysis and/or decision making involved. The supervised role is implemented using an Ethernet architecture, whereby the supervised link or "command station" becomes an extra node on a managed network (represented by the UUV) over which the acquired data is shared. In so doing, the command station is able to monitor/eavesdrop/gain access to data that is moving around the network. The data is still logged on board but, in addition, some or all of the data can be transmitted to the command station so that the data is in two places, substantially simultaneously. The operator then has the ability to influence an activity of the vehicle 32, 52 by submitting an instructing signal down the data cable 40, 56 using standard Ethernet and transmission control protocol (TCP) processes.

One example of when the operator may be inclined to intervene and influence the activity of the vehicle may be when the vehicle is being used to investigate the hull of a vessel. The vehicle uses its autonomous capabilities to determine relative locations of vehicle to vessel, to effect movement of the vehicle relative to the hull of the vessel. The UUV is the optimal tool to control its own spatial positioning in light of its sensor inputs. However, if the optical or acoustic sensors are receiving imagery that is potentially ambiguous, the human eye or even a base station machine based operator (having access to broader database information) may be more able to interpret the findings detected by the sensors and recognise an object or anomaly discovered thereby. In particular, a human operator may intuitively identify anomalous features that the vehicle or even a machine operator would fail to notice.

Once the supervised mode has been completed the vehicle 32 may return to the base station 34 and the cable 40 may be retracted by the spool assembly 38. In a less sophisticated embodiment, the cable 40 may be dispensed and recovered manually by an operator located at the base station 34.

The plug 42 and socket 44 may be configured such that they are automatically releasable from one another. If so, it may be desirable to separate the cable 40 from the vehicle 32 prior to recovery of each to enhance the recovery process. Furthermore, this ability to separate the cable 40 from the vehicle enables the vehicle to continue a given mission in a fully autonomous mode, once the supervised period/session has been completed without returning to the base station 34. Thus the versatility of the vehicle 32 is yet further enhanced.

In the second embodiment, the expandable cable 56 may be discarded entirely. The cable 56 may be subjected to a level of tension so that it breaks, preferably in the vicinity of the second spool assembly 50. Alternatively, the cable 56 may be severed by a cutting mechanism (not illustrated) provided in the, or each, spool assembly 48, 50. The cutting mechanism may be actuated in response to a signal from the base station 54.

In yet a further alternative, the second spool assembly 50 is releasably mounted on the vehicle 52 and is, itself considered to be expendable. Once the supervised mode has been completed, or in the event that the fibre optic cable 56 is inadvertently severed and data transfer is interrupted or otherwise prevented, the second spool assembly 50 may be released from the vehicle 52. In this way, any detrimental effect experienced by the vehicle 52 due to the presence of the spool assembly 50 is eliminated.

Claims

An autonomous underwater vehicle comprising:

a body portion;

a processing device mounted within the body portion;

a sensor mounted on or within in the body portion; and data output means configured to enable connection of the processing device to a physical data carrier during operation of the vehicle.

A vehicle according to Claim 1 provided in combination with a data carrier, wherein the data carrier comprises dispensing means for dispensing a length of data transfer cable.

A vehicle according to Claim 2, wherein the data carrier comprises one of the group of severing means, releasing means and retracting means for separating the data transfer cable from the vehicle or stowing the data transfer cable after use.

A vehicle according to Claim 2 or Claim 3, wherein the data transfer cable is a fibre optic cable.

A vehicle according to any of Claims 2 to 4, wherein the dispensing means comprises a spool assembly.

A vehicle according to Claim 5, wherein the spool assembly is configured to be neutrally buoyant.

A vehicle according to Claim 5 or Claim 6, wherein the spool assembly comprises a sub-assembly associated with a base station from which the vehicle is launched.

A vehicle according to any of Claims 5 to 7, wherein the spool assembly comprises a sub-assembly associated with and mounted on the vehicle.

A data carrier, comprising dispensing means for dispensing a length of cable and a releasable connection means for connecting the data carrier to an autonomous underwater vehicle.

10. A data carrier according to Clainn 9, wherein the releasable connection means comprises an electromechanical release mechanism.

1 1 . A data carrier according to Claim 10, wherein the electromechanical release mechanism comprises a latching mechanism.

12. A data carrier according to any of Claims 9 to 1 1 , wherein the connection means is configured to be released from the vehicle upon receipt of an instruction from a base station from which the vehicle was launched.

13. A data carrier according to any of Claims 9 to 1 1 , wherein the connection means is configured to be released upon a detected behaviour of the vehicle.

14. A method of operation of an unmanned underwater vehicle (UUV) comprising the steps of:

determining a mode of operation of the vehicle, dependent on mission criteria;

supplying instructions to the vehicle;

launching vehicle from a base station;

if the determined mode of operation is a supervised mode, dispensing a transfer cable connected between the vehicle and the base station;

collecting data from sensors located on board the vehicle; and

returning data from the vehicle to the base station via the cable.

15. A method according to Claim 14, wherein the dispensing step comprises attaching a distal end of a data transfer cable to the vehicle and dispensing a length of data transfer cable from the base station.

16. A method according to Claim 14, substantially simultaneously dispensing a first portion of a data transfer cable connected to the vehicle and a second portion of a data transfer cable connected to a base station from which the vehicle is launched;

17. A method according to any of Claims 14 to 16, comprising the steps of: analysing data collected by the UUV; and

returning a sub-set of the collected data to the base station.

18. A method according to Claim 14 to 17, comprising the steps of:

determining whether changes in the supplied instructions are required, dependent on the returned data; and

transmitting the changes to the UUV, via the data transfer cable.

19. A method according to any of Claims 14 to 18, comprising the steps of:

separating the vehicle from the base station; and continuing operation of the vehicle in an autonomous mode.

20. An autonomous underwater vehicle, substantially as herein described and with reference to the accompanying drawings.

21 . A data carrier, substantially as herein described and with reference to the accompanying drawings.

22. A method, substantially as herein described and with reference to the accompanying drawings.