WO2015176133A1

WO2015176133A1 - Shark detection system

Info

Publication number: WO2015176133A1
Application number: PCT/AU2015/050265
Authority: WO
Inventors: Hamish Jolly; Craig Anderson
Original assignee: Shark Mitigation Systems Pty Ltd
Priority date: 2014-05-22
Filing date: 2015-05-22
Publication date: 2015-11-26
Also published as: AU2015101922A4; AU2015263856A1

Abstract

A shark detection system (10) comprising one or more sonar transducers (12) secured to a seabed (18) to detect sonar signals in a region (20) defined by one or more boundary lines. The sonar transducers (12) are directed perpendicular to the boundary line at locations along the boundary line. An equipment housing (14) is connected to the sonar transducers (12) by a signal cable (30) and processing equipment and a communications device are provided within the housing (14). The sonar transducers (12) provide information regarding detected sonar signals via the signal cable (30) to the processing equipment, the processing equipment analyses the received information to determine whether any objects detected match the characteristics of a shark and the communications device transmits a signal to be received by a remote station on determination that a shark has been detected.

Description

"SHARK DETECTION SYSTEM

Field of the Invention

[001 ] The present invention relates to a system for detection of sharks.

Background to the Invention

[002] With increasing numbers of shark attacks on swimmers in various locations, the issue of minimizing the risk of such shark attacks is becoming increasingly important. Various techniques have been employed to reduce the risk of shark attacks, including physical barriers and aerial patrols. While such approaches provide some level of risk reduction, further methods that are easy to implement and cost effective would be beneficial.

[003] The present invention relates to a detection system which may be implemented in order to detect and warn against the presence of sharks in a particular location. The system comprises features aimed at providing effective warning to relevant persons and ease of installation and use.

Summary of the Invention

[004] According to one aspect of the present invention there is provided a shark detection system comprising:

one or more sonar transducers secured to a seabed to detect sonar signals in a region defined by one or more boundary lines, the sonar transducers being directed perpendicular to the boundary line at locations along the boundary line;

an equipment housing connected to the sonar transducers by a signal cable; processing equipment provided within the housing; and

a communications device provided with the housing;

wherein the sonar transducers provide information regarding detected sonar signals via the signal cable to the processing equipment, the processing equipment analyses the received information to determine whether any objects detected match the characteristics of a shark and the communications device transmits a signal to be received by a remote station on determination that a shark has been detected. [005] Preferably the sonar transducers are provided to emit a sonar signal into a region located on a first side of the sonar transducer and to detect signals returned from the region wherein the region is defined by a predefined horizontal detection angle and a predefined vertical detection angle.

[006] Preferably each sonar transducer is fixed relative to the seabed on a mounting frame comprising a base and a plurality of legs, the legs being connected around the periphery of the base to extend perpendicularly to the base and the position of the legs relative to the base being adjustable.

[007] In a preferred embodiment, the legs are to be secured into the seabed and the position of the base relative to the legs may be adjusted to vary the height of the base above the seabed and the angle of the base, and therefore of the sonar transducer.

[008] In one embodiment the housing comprises a domed shape housing provided on an upper surface of the base.

[009] Preferably the regions sensed by the sonar transducers are defined by the predetermined horizontal detection angle, the predetermined vertical detection angle and a range such that the regions include first and second vertical sides defining the sides of the region.

[010] Preferably the sonar transducers are arranged such that the vertical sides of each region within the range are overlapping or adjacent. [01 1 ] Preferably position of the sonar transducers is set such that the regions of adjacent zones overlap by an overlap distance, being a distance perpendicular to the direction of the line of sonar transducers from the intersection of the adjacent vertical sides out to the range and wherein the overlap distance is set, based on the expected speed of movement of a species of shark to be detected and the time taken for the shark to traverse the overlap distance.

[012] In one embodiment, the sonar transducers are arranged relative to each of the boundary lines such that some of the sonar transducers point outwardly relative to the boundary line and other sonar transducers point inwardly relative to the boundary line.

[013] In one embodiment the sonar transducers along each boundary line point alternatively outwardly and inwardly and the sonar transducers are offset either side of the boundary line such that the sonar transducers directed outwardly are located on an inner side of the boundary line and the sonar transducers directed inwardly are located on an outer side of the boundary line such that the vertical sides of each adjacent pair of sonar transducers are therefore parallel to and adjacent each other.

[014] In one embodiment the sonar transducers are offset either side of the boundary line by half the range.

[015] In one embodiment the sonar transducers are offset either side of the boundary line by a distance greater than half of the range.

[016] Preferably the vertical detection angle of the sonar transducers is set such that a lower surface of the region is located adjacent and generally parallel to the seabed.

[017] Preferably the vertical detection angle is set such that the region covered extends from adjacent the seabed to adjacent the surface of the water at the range.

[018] In a preferred embodiment the vertical detection angle is equal to or between 10 and 20 degrees.

[019] Preferably the processing equipment is provided to analyse the information received from the sonar transducer to determine whether any signals received from the region match predetermined characteristics indicating the presence of a shark within the region. [020] In a preferred embodiment the predetermined characteristics include the size of detected objects within the region and a comparison between the direction of movement of an object and the direction of the water current within the region. [021 ] Preferably the processing equipment includes predefined stored signals against which the information received by the sonar transducer may be compared, wherein the predefined stored signals include signals generated by receiving sonar information from sharks moving within water.

[022] Preferably the communications equipment sends the warning signal via a telecommunications network.

[023] In one embodiment the warning signal is sent to a server located on a communication network to be accessed by multiple users via an application on a portable communications device.

[024] In one embodiment the platform is provided with visible and audible warnings to be activated on detection of a shark.

[025] In accordance with a further aspect of the present invention, there is provide a method of detection of sharks comprising the steps of:

locating a plurality of sonar transducers secured to a seabed to detect sonar signals in a region defined by one or more boundary lines, the sonar transducers being directed perpendicular to the boundary line at locations along the boundary line and the regions sensed by the sonar transducers being defined by a predetermined horizontal detection angle, a predetermined vertical detection angle and a range;

wherein the position of the sonar transducers is set such that the regions of adjacent zones overlap by an overlap distance, being a distance perpendicular to the direction of the line of sonar transducers from the intersection of the adjacent vertical sides out to the range and wherein the overlap distance is set based on the expected speed of movement of a species of shark to be detected and the time taken for the shark to traverse the overlap distance. [026] Preferably the method includes the steps of setting the vertical detection angle of the sonar transducers such that a lower surface of the region is located adjacent and generally parallel to the seabed.

[027] Preferably the method includes setting the vertical detection angle such that the region covered extends from adjacent the seabed to adjacent the surface of the water at the range.

[028] Preferably the vertical detection angle is set equal to or between 10 and 20 degrees.

Brief Description of the Drawings

[029] The invention will now be described, by way of example, with reference to the following drawings, in which:

[030] Figure 1 a is a top view of an arrangement of sonar transducers in accordance with the shark detection system of the present invention;

[031 ] Figure 1 b is a top view of the shark detection system of Figure 1a showing cable connections and a floating platform;

[032] Figure 2a is a side view of a sonar transducer provided on a mounting frame on the seabed in accordance with the present invention;

[033] Figure 2b is a side view of the mounting frame of Figure 2b raised off the seabed to account for obstacles;

[034] Figure 3a is a side cross sectional view showing a region to be sensed by the sonar transducer;

[035] Figure 3b is a top view of a representation of sensed regions created by a first arrangement of sonar transducers;

[036] Figure 4a is a top view of a representation of sensed regions created by a second arrangement of sonar transducers;

[037] Figure 4b is a side cross sectional view of the sensed regions of Figure 4a through the line A-A;

[038] Figure 5b is a side cross sectional view of the regions of Figure 4a along path B. Detailed Description of Preferred Embodiments

[039] Referring to the Figures, there is shown a shark detection system 10 comprising generally one or more sonar transducers 12 and an equipment housing. In the embodiment shown, the equipment housing comprises a floating platform 14 secured to float on the surface of the water above the sonar transducers 12. The shark detection system 10 in the embodiment shown is located at a position adjacent an area of coastline 1 1 .

[040] The shark detection system 10 comprises a plurality of sonar transducers 12 located adjacent the coastline 1 1 . The sonar transducers 12 in the embodiment shown comprise an outer set of transducers 12a, a first side set of sonar transducers 12b and a second side set of sonar transducers 12c. The outer set of sonar transducers 12a are located along an outer boundary line generally parallel to the coastline 22. The first and second sets of sonar transducers 12b and 12c are arranged alongside boundary lines extending from opposed ends of the outer boundary line towards the coastline 1 1. The sonar transducers 12 thereby define a zone 13 within the sonar transducers 12 which is to be protected by detection of sharks entering the zone 13.

[041 ] Each of the sonar transducers 12 is provided in a housing 16 to be secured to the seabed 18. The sonar transducer 12 is provided to emit a sonar signal into a region 20 located on a first side of the sonar transducer 12 and to detect signals returned from the region 20. The region 20 is defined by a predefined horizontal detection angle 24 and a predefined vertical detection angle 25.

[042] Each sonar transducer 12 is fixed relative to the seabed 18 on a mounting frame 22. In the embodiment shown, the mounting frame 22 comprises a base 26 and a plurality of legs 28. The housing 16 comprises a domed shape housing and the base 26 comprise a generally planar member such having an upper surface to which the housing 16 is secured. The legs 28 are connected around the periphery of the base 26 to extend perpendicularly to the base 26. The position of the legs 28 relative to the base 26 is adjustable.

[043] The legs 28 are to be secured into the seabed 18 and the position of the base 26 relative to the legs 28 may be adjusted to vary the height of the base 26 above the seabed 18 and the angle of the base 26, and therefore of the housing 16. The base 26 may be located adjacent the seabed 18 (as shown in Figure 2a) or raised from the seabed 18 (as shown in Figure 2b) in order to avoid obstacles on the seabed 18. The position and angle of the housing 16, and therefore the sonar transducer 12, relative to the seabed 18 may thereby also be selected to optimise performance of the shark detection system 10.

[044] The equipment platform 14 is connected to the sonar transducers 12 by one or more signal cables 30. In the embodiment shown, signal cables 30 extend from each of the sonar transducers 12 to one or more junction housings 32 located on the seabed 18. The junction housings 32 are connected together by a further signal cable 30 and a riser cable 33 extends upwardly from one of the junction housings 32 to the floating platform 14.

[045] Information received by the sonar transducer 12 from the region 20 is transmitted to the equipment platform 14 over the signal cables 30. The equipment platform 14 includes processing equipment located therein to receive and analyse the information from the sonar transducers 12. The processing equipment comprises a suitable computer processor and associated software.

[046] The processing equipment is provided to analyse the information received from the sonar transducers 12 to determine whether any signals received from the region 20 match predetermined characteristics which would indicate the presence of a shark within the region 20. [047] The predetermined characteristics may include a plurality of characteristics, including the size of any detected object within the region 20. Further, the processing equipment will analyse the information to detect the direction of movement of objects within the region 20. The system is provided also with current sensing means to provide information regarding the direction of movement of water currents within the region 20. The processing equipment is configured to compare the direction of movement of objects within the region 20 to the sensed water currents. The detection of objects greater than a predetermined size and moving in a direction differing from that of the water current is used to determine the possibility of a shark within the region 20.

[048] Further characteristics may also be analysed to determine the existence of a shark within the region 20. The processing equipment may include predefined stored signals against which the information received by the sonar transducers 12 may be compared. The predefined stored signals may include signals generated by receiving sonar information from sharks moving within water. Such sonar information will provide information on the sharks' swimming patterns to be stored within the predefined stored signals. By obtaining sonar signatures of various sharks, a set of signature signals may be generated and stored within the system. Should the processing equipment determine that the received information sufficiently matches any of the stored signature signals, then the processing equipment may use this to determine the presence of a shark within the region 20.

[049] Further characteristics may be sensed by the processing equipment to distinguish between a shark and other moving creatures within the water, such as whales or other mammals, based on stored information regarding the characteristics of these mammals.

[050] The platform 14 includes also communications equipment. The communications equipment is provided to send a warning signal to relevant persons when the processing equipment detects the presence of a shark within one the regions 20. The communications equipment may send the warning signal via a telecommunications network. The warning signal can be sent to any relevant persons, such as beach patrol personnel in the area. The warning signal may also be sent to a server located on a communication network to be accessed by multiple users. An application may be provided on a portable communications device, such as a mobile phone, which can access the server in order to be notified of any warning signals generated by the system. Beachgoers in the area may therefore have access to notifications regarding shark warnings via their phone.

[051 ] The communications equipment may also send the received sonar information from the sonar transducer 12 directly to a remote computing device for display on an output screen.

[052] The arrangement of the regions 20 of each of the sonar transducers 12 relative to each other is arranged to effectively detect the presence of sharks in a manner which allows suitable time to activate a warning before the shark enters the zone 13.

[053] The regions sensed by the sonar transducers 12 are defined by the predetermined horizontal detection angle 24, the predetermined vertical detection angle 25 and a range 34. The regions 20 therefore include first and second vertical sides 36 and 37 defining the sides of the region 20. In order to ensure detection of sharks entering the zone 13, the sonar transducers 12 are arranged such that the the vertical sides 36 and 37 of each region 20 within the range 34 are overlapping or adjacent.

[054] As shown in the embodiment of Figure 3b, positions of the sonar transducers 12 are arranged along each of the boundary lines such that the sonar transducers point outwardly. The position of the sonar transducers 20 is set such that the regions 20 of adjacent zones 1 1 overlap by an overlap distance 40, being a distance perpendicular to the direction of the line of sonar transducers 12 from the intersection of the adjacent vertical sides 36 and 37 out to the range 34. This overlap distance 40 is set such that, based on the expected speed of movement of species of sharks to be detected, the time taken for a shark to traverse the overlap distance is sufficient for the processing equipment to perform recognition of the shark.

[055] Figure 4a shows an alternative arrangement of sonar transducers 12. In the embodiment of Figure 4a, the sonar transducers 12 are arranged relative to each of the boundary lines such that some sonar transducers 12 point outwardly relative to the boundary line and other sonar transducers 12 point inwardly relative to the boundary line. In particular, the sonar transducers 12 along each boundary line point alternatively outwardly and inwardly. The sonar transducers 12 are offset either side of the boundary line such that the sonar transducers 12 directed outwardly are located on an inner side of the boundary line and the sonar transducers 12 directed inwardly are located on an outer side of the boundary line. The vertical sides 36 and 37 of each adjacent pair of sonar transducers 12 are therefore parallel to and adjacent each other, as can be seen in Figure 4a. Such an arrangement reduces broadens the depth of the total area formed by the sensed regions 20 to reduce the likelihood that a shark would cross the regions 20 without detection.

[056] In the embodiment of Figure 4, the sonar transducers 12 are offset either side of the boundary line by approximately half the range 34. Figure 5 shows an alternative embodiment in which the sonar transducers 12 are offset either side of the boundary line by a distance greater than half of the range 34.

[057] The vertical detection angle 25 of the sonar transducers 12 is set such that a lower surface of the region 20 is located adjacent and generally parallel to the seabed 18. The angle of the sonar transducer 12 may be adjusted by varying the angle of the base 26 of the mounting frame 22. The vertical detection angle 25 is set such that the region covered extends from adjacent the seabed 18 to adjacent the surface of the water at the range 34. It is expected that vertical detection angles 25 between 10 and 20 degrees would be used.

[058] The equipment platform 14 may also be provided with a fluid release mechanism. The fluid release mechanism is in communication with the processing equipment to be activated on detection of a shark within any of the region 20. The fluid release mechanism is configured to release a fluid from a vessel within the platform 14 into the water on detection of a shark. The fluid may be, for example, a coloured dye to provide a visual indication to persons in the area of the detection of a shark. The platform 14 may also be provided with a visible and audible warning activated on detection of a shark, such as a warning light and siren. [059] Further, the equipment platform 14 or one or more of the housings 16 is provided with an acoustic tag sensor. The acoustic tag sensor is provided to receive signals from tags that have been attached previously to sharks. The acoustic tag sensor is provided to detect the presence of these tags and to activate the warning signal.

[060] While the equipment housing in the embodiment shown comprises a floating platform 24, it will be appreciated that other arrangements may be utilised. For example, in a further embodiment, the equipment platform may comprise a buoy in which the equipment is contained. Alternatively, the signal cables 30 may extend to the coastline 1 1 and the equipment housing will be provided on land adjacent the coastline 1 1 .

[061 ] It will be readily apparent to persons skilled in the relevant arts that various modifications and improvements may be made to the foregoing embodiments, in addition to those already described, without departing from the basic inventive concepts of the present invention.

Claims

1. A shark detection system comprising:

a communications device provided with the housing;

wherein the sonar transducers provide information regarding detected sonar signals via the signal cable to the processing equipment, the processing equipment analyses the received information to determine whether any objects detected match the characteristics of a shark and the communications device transmits a signal to be received by a remote station on determination that a shark has been detected.

2. A shark detection system in accordance with claim 1 , wherein, the sonar transducers are provided to emit a sonar signal into a region located on a first side of the sonar transducer and to detect signals returned from the region wherein the region is defined by a predefined horizontal detection angle and a predefined vertical detection angle.

3. A shark detection system in accordance with claim 1 or 2 wherein each sonar transducer is fixed relative to the seabed on a mounting frame comprising a base and a plurality of legs, the legs being connected around the periphery of the base to extend perpendicularly to the base and the position of the legs relative to the base being adjustable.

4. A shark detection system in accordance with claim 3, wherein legs are to be secured into the seabed and the position of the base relative to the legs may be adjusted to vary the height of the base above the seabed and the angle of the base, and therefore of the sonar transducer.

5. A shark detection system in accordance with claim 4, wherein the housing comprises a domed shape housing provided on an upper surface of the base.

6. A shark detection system in accordance with any one of claims 2 to 5, wherein the regions sensed by the sonar transducers are defined by the predetermined horizontal detection angle, the predetermined vertical detection angle and a range such that the regions include first and second vertical sides defining the sides of the region.

7. A shark detection system in accordance with claim 6, wherein the sonar transducers are arranged such that the vertical sides of each region within the range are overlapping or adjacent.

8. A shark detection system in accordance with claim 7, wherein position of the sonar transducers is set such that the regions of adjacent zones overlap by an overlap distance, being a distance perpendicular to the direction of the line of sonar transducers from the intersection of the adjacent vertical sides out to the range and wherein the overlap distance is set, based on the expected speed of movement of a species of shark to be detected and the time taken for the shark to traverse the overlap distance.

9. A shark detection system in accordance with claim 6, wherein the sonar transducers are arranged relative to each of the boundary lines such that some of the sonar transducers point outwardly relative to the boundary line and other sonar transducers point inwardly relative to the boundary line.

10. A shark detection system in accordance with claim 9, wherein the sonar transducers along each boundary line point alternatively outwardly and inwardly and the sonar transducers are offset either side of the boundary line such that the sonar transducers directed outwardly are located on an inner side of the boundary line and the sonar transducers directed inwardly are located on an outer side of the boundary line such that the vertical sides of each adjacent pair of sonar transducers are therefore parallel to and adjacent each other.

1 1 . A shark detection system in accordance with claim 10, wherein the sonar transducers are offset either side of the boundary line by half the range.

12. A shark detection system in accordance with claim 10, wherein the sonar transducers are offset either side of the boundary line by a distance greater than half of the range.

13. A shark detection system in accordance with any one of the preceding claims, wherein the vertical detection angle of the sonar transducers is set such that a lower surface of the region is located adjacent and generally parallel to the seabed.

14. A shark detection system in accordance with claim 13, wherein the vertical detection angle is set such that the region covered extends from adjacent the seabed to adjacent the surface of the water at the range.

15. A shark detection system in accordance with claim 14, wherein the vertical detection angle is equal to or between 10 and 20 degrees.

16. A shark detection system in accordance with any one of the preceding claims, wherein the processing equipment is provided to analyse the information received from the sonar transducer to determine whether any signals received from the region match predetermined characteristics indicating the presence of a shark within the region.

17. A shark detection system in accordance with claim 16, wherein the predetermined characteristics include the size of detected objects within the region and a comparison between the direction of movement of an object and the direction of the water current within the region.

18. A shark detection system in accordance with claim 17, wherein the processing equipment includes predefined stored signals against which the information received by the sonar transducer may be compared, wherein the predefined stored signals include signals generated by receiving sonar information from sharks moving within water.

19. A shark detection system in accordance with any one of the preceding claims, wherein the communications equipment sends the warning signal via a telecommunications network.

20. A shark detection system in accordance with claim 19, wherein the warning signal is sent to a server located on a communication network to be accessed by multiple users via an application on a portable communications device.

21 . A shark detection system in accordance with any one of the preceding claims, wherein the platform is provided with visible and audible warnings to be activated on detection of a shark.

22. A method of detection of sharks comprising the steps of:

wherein the position of the sonar transducers is set such that the regions of adjacent zones overlap by an overlap distance, being a distance perpendicular to the direction of the line of sonar transducers from the intersection of the adjacent vertical sides out to the range and wherein the overlap distance is set based on the expected speed of movement of a species of shark to be detected and the time taken for the shark to traverse the overlap distance.

23. A method in accordance with claim 22, comprising the steps of setting the vertical detection angle of the sonar transducers such that a lower surface of the region is located adjacent and generally parallel to the seabed.

24. A method in accordance with claim 23, wherein the vertical detection angle is set such that the region covered extends from adjacent the seabed to adjacent the surface of the water at the range.

25. A method in accordance with claim 24, wherein the vertical detection angle is equal to or between 10 and 20 degrees.