A method for explosive ordnance clearing

Abstract

A method for explosive ordnance clearing, comprising transporting an explosive ordnance clearing device (20) to a close proximity of an explosive ordnance (10), wherein the explosive ordnance clearing device (20) comprises a clearing explosive (21), a detonator to detonate the clearing explosive (21), means (22, 32) for fuse ignition to ignite the detonator, and a first conductor (27, 37) connected to the means (22, 32) for fuse ignition, transporting one of an electric charge and a heat agent (44) to the close proximity of the explosive ordnance clearing device (20) with an ignition unmanned aerial vehicle (41), wherein the ignition unmanned aerial vehicle (41) comprises a second conductor (45, 48), bringing one of the electric charge and the heat agent (44) into connection with the second conductor (45, 48) to the first conductor (27, 37) for igniting the means (22, 32) for fuse ignition, and moving the ignition unmanned aerial vehicle (41) to a distance from the explosive ordnance (10).

Description

[0001] A METHOD FOR EXPLOSIVE ORDNANCE CLEARING

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a method and an arrangement for explosive ordnance clearing and particularly to increasing safety of explosive ordnance clearing processes.

[0004] BACKGROUND OF THE INVENTION

[0005] One of the problems associated with clearing the explosive ordnances such as mines, improvised explosive devices or unexploded ammunitions is ensuring safety of the personnel doing the explosive ordnance clearance. Transporting a clearing explosive to an explosive ordnance by foot places the personnel in obvious danger. The task of clearing explosive ordnances can be very extensive and clearing explosive ordnances one by one makes the process very slow.

[0006] Secondly, due to the high number of explosive ordnances that may need to be cleared, a clearing process should be affordable and safe to use.

[0007] BRIEF DESCRIPTION OF THE INVENTION

[0008] An objective of the present invention to provide a method and an arrangement for implementing the method to solve the above problems. The objects of the invention are achieved by a method and an arrangement which are characterized by what is stated in the independent claims. The preferred embodiments of the invention are disclosed in the dependent claims.

[0009] The invention is based on the idea of first to transport an explosive ordnance clearing device into a close proximity of an explosive ordnance [EO] to be cleared without an ignition energy. The intended effect of the explosive ordnance clearing device is to break the explosive ordnance in such a way that is not able to detonate, to detonate the EO or to move the EO away to a desired direction from its location. Second, the ignition energy is brought to the explosive ordnance clearing device by an unmanned aerial vehicle, which is carrying the ignition energy, and has means for bringing the ignition energy in contact with the explosive ordnance clearing device.

[0010] The advantage of the method and arrangement of the invention is that the explosive ordnance clearing device can be handled and moved safely since it does not comprise the ignition energy. Secondly, the ignition energy is transported by an unmanned aerial vehicle to the explosive ordnance clearing device to detonate it in such a way that the operator can work from a safe distance and location.

[0011] BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In the following the invention will be described in greater detail by means of preferred embodiments with reference to the attached drawings, in which:

[0013] Figures la -le illustrate the method of explosive ordnance clearing.

[0014] Figure 2 illustrates an explosive ordnance clearing device;

[0015] Figure 3 illustrates an unmanned aerial vehicle with conductor for igniting an explosive ordnance clearing device;

[0016] Figure 4 illustrates an unmanned aerial vehicle with an electric charge igniting the explosive ordnance clearing device;

[0017] Figure 5 illustrates an unmanned aerial vehicle with a heat agent igniting the explosive ordnance clearing device;

[0018] Figure 6a, 6b and 6c illustrate a visual marker and an optical guidance aid an explosive ordnance clearing device, respectively.

[0019] DETAILED DESCRIPTION OF THE INVENTION

[0020] Figures la-le, 2, and 3 are illustrating an embodiment of a method for explosive ordnance clearing, wherein an explosive ordnance clearing device 20 is transported (Fig. la) to a close proximity A of an explosive ordnance 10. The transportation may be done e.g. by an unmanned vehicle. In Figures la and lb the unmanned vehicle in an unmanned aerial vehicle 40. Referring to Figure 2, the explosive ordnance clearing device 20 comprises a clearing explosive 21, a detonator to detonate the clearing explosive 21, means for fuse ignition 22 to ignite the detonator, and a first conductor 27 connected to the means for fuse ignition 22. The clearing explosive 21 comprises an amount of explosive material to clear the explosive ordnance 10 when the explosive is detonated at a close proximity of the explosive ordnance 10. The required proximity A may vary between 0 cm to few tens of centimetres. The proximity position may be above, below or next to the explosive ordnance 10 depending on the placement and the surroundings of the explosive ordnance. The required amount of explosive may vary between few hundred grams to two kilograms, but in practice it is only limited by the capacity of the transportation. The means for fuse ignition 22 enable delayed ignition from the time instant when the means for fuse ignition 22 is ignited to the time instant of the detonation of the clearing explosive 21. This time delay may between approximately 20 seconds to one minute, but it is not limited to these. The purpose of the delay is to provide sufficient time for an ignition unmanned aerial vehicle (UAV) 41 transporting the ignition energy to move to a safe distance before detonation of the clearing explosive 21. The means for fuse ignition 22 maybe e.g. a safety fuse or an igniter cord. The first conductor 27 comprises means for bringing ignition energy in contact with the means for fuse ignition 22. In the next phase (Fig. lc), the ignition UAV 41 transports one of an electric charge and a heat agent 44 to the close proximity of the explosive ordnance clearing device 20 with, wherein the unmanned aerial vehicle comprises a second conductor 45 to bring the transports one of an electric charge and a heat agent 44 in contact with the first conductor 27 for igniting the means for fuse ignition 22. Finally, after the ignition of the means for fuse ignition 22, the ignition UAV 41 is moved (Fig. Id) to a sufficient distance D from the explosive ordnance 10 during the time delay of the means for fuse ignition 22. Referring to Figure le, the ignition UAV may also detect the detonation 19 of the clearing explosive 21.

[0021] According to another embodiment of the method, the explosive ordnance clearing device 20 is transported to a close proximity of the explosive ordnance 10 with an unmanned vehicle. The unmanned vehicle is one of the ignition UAV 41, a transport UAV 40, an unmanned surface vessel (USV), and an unmanned ground vehicle (UGV). The achieved proximity of the transportation of the explosive ordnance clearing device 20 with respect to the explosive ordnance 10 to be cleared may vary. For obvious reasons the proximity achieved with an USV may be less than with an UAV or with an UGV. Also, for obvious reasons the amount of explosive material in the clearing explosive 21 may be larger when using an USV or an UGV. The one of an electric charge and a heat agent 44 may be transported by the ignition UAV 41 such that in a first flight the ignition UAV 41 transport the explosive ordnance clearing device 20 into a close proximity of the explosive ordnance 10, and on a second flight after the first flight the ignition UAV 41 transports the one of an electric charge and a heat agent 44.

[0022] According to another embodiment of the method the ignition UAV 41 is guided into a position with the explosive ordnance clearing device 20 by one of a visual marker 50, and an optical guiding aid 51 in the explosive ordnance clearing device 20. Figures 6a and 6b show the explosive ordnance clearing device 20 from the above. The visual marker 50 and the optical guidance aid 51 are facing upwards to provide an aiming target for the explosive ordnance clearing device 20. It is common in the skill of the art that unmanned vehicles are equipped with cameras and a wireless data link for providing visual view to the operator of the unmanned vehicle for manoeuvring the vehicle. The approach of the ignition UAV 41 is assisted by using same camera 54 to bring the ignition UAV 41 to a desired position with respect to the explosive ordnance clearing device 20. For assisting the approach, the explosive ordnance clearing device 20 may comprise the visual marker 50, to which the operator can aim the ignition UAV 41. The operator may receive a reference measure of height and width by observing the pattern to estimate the distance of the ignition UAV 41 via the visual view.

[0023] The operator may also estimate the orientation of the ignition UAV 41 with respect to the explosive ordnance clearing device 20 using the camera 54 and the visual marker 50. The visual marker 50 may also comprise a pattern that can be used by the operator in estimating the orientation. The estimation of the distance and of the orientation of the ignition UAV 41 with respect to the explosive ordnance clearing device 20 may also be automated with an image processing system at the operator side so that the image processing system uses the visual data provided by the camera 54 to provide control instruction to the ignition UAV 41 or control assistance to the operator. Alternatively, instead of the visual marker 50, the explosive ordnance clearing device 20 may comprise an optical guidance aid 51 for guiding the ignition UAV 41 into a position with the explosive ordnance clearing device 20, wherein the optical guidance aid 51 comprises means for reflecting a light actuation such that an actuating light beam from the ignition UAV 41 is reflected by the optical guidance aid 51. One of a wavelength, intensity, and pattern of the reflected light depends on the tilt or the orientation of the light beam with respect to optical guidance aid 51. It is known in the art of optical system to arrange orientation-dependent reflection of light beam.

[0024] According to another embodiment of the method a detonation of the clearing explosive 21 is detected by means for detecting an explosion, and information of the detonation is transmitted wirelessly from the ignition UAV 41. The detection may be performed by a microphone in the ignition UAV 41 detecting a sound and the transmitting the sound wirelessly to the operator or by transmitting information about the explosion to an operator device. Alternatively, the ignition UAV 41 may comprise means for detecting a sound of explosion by comparing the microphone signal to pre-stored characteristic of an explosion and taking into account the distance of the ignition UAV 41 to the explosive ordnance clearing device 20. The distance may be estimated with the flight control data or by the visual information provided by the visual marker 50 or the visual guidance aid 51. Alternatively, the detection may be performed by the camera 54 of the ignition UAV 41 detecting a flash of the explosion and the transmitting the information of the explosion wirelessly to the operator device.

[0025] According to another embodiment of the method the electric charge is connected to the means for fuse ignition 22 using the first and second conductor 45. The ignition UAV 41 may bring the second conductor 45 into contact with first conductor 27 of the explosive ordnance clearing device 20 as described in a previous embodiment. An electric voltage is provided via the second conductor 45 to the first conductor 27 and further to the means for fuse ignition 22. The electric charge may be transported by at least one of a battery 43 and a capacitor. It is known in the art how to arrange an electric current enough to ignite a fuse ignition.

[0026] According to another embodiment of the method the ignition UAV 41 is transporting the heat agent 44 into close proximity of the explosive ordnance clearing device 30. The second conductor 48 is guiding the heat agent 44 to the means for fuse ignition 32. The heat agent 44 may be released from the second conductor 48, or it may only brough into contact with the first conductor 37.

[0027] According to another embodiment of the method in bringing the first conductor 37 into connection with the second conductor 48 for igniting the means for fuse ignition 32, at least one of the first and second conductor 48 is guiding the at least second and first conductor 37 into a contact, respectively.

[0028] Referring to Figure 2, according to another embodiment there is an arrangement for explosive ordnance clearing, comprising an explosive ordnance clearing device 20 configured to be transported to a close proximity of an explosive ordnance 10. The explosive ordnance clearing device 20 comprises a clearing explosive 21, a detonator to detonate the clearing explosive 21, means for fuse ignition 22 to ignite the detonator, and a first conductor 27 connected to the means for fuse ignition 22. The clearing explosive 21 comprises an amount of explosive material to detonate the explosive ordnance 10 when the explosive is detonated at a close proximity of the explosive ordnance 10. The required proximity may vary between 0 cm to few tens of centimetres. The required amount of explosive may vary between few hundred grams to multiple kilograms, but in practice it is only limited by the capacity of the transportation. The means for fuse ignition 22 enable delayed ignition from the time instant when the means for fuse ignition 22 is ignited to the time instant of the detonation of the clearing explosive 21. This time delay may between 2 seconds to few minutes, but it is not limited to these. The purpose of the delay is to provide sufficient time for an ignition unmanned aerial vehicle (UAV) 41 transporting the ignition energy to move to a safe distance before detonation of the clearing explosive 21. The means for fuse ignition 22 maybe e.g. a safety fuse or an igniter cord. The first conductor 27 comprises means for bringing ignition energy in contact with the means for fuse ignition 22. The ignition UAV 41 transports one of an electric charge and a heat agent 44 to the close proximity of the explosive ordnance clearing device 20 with, wherein the unmanned aerial vehicle comprises a second conductor 45 to bring the transports one of an electric charge and a heat agent 44 in contact with the first conductor 27 for igniting the means for fuse ignition 22. In figure 2, the first conductor 27 comprises a first lead 25 and a second lead 26, which are configured to receive electric contact from the ignition UAV 41. Finally, after the ignition of the means for fuse ignition 22, the ignition unmanned aerial vehicle is moved to a sufficient distance from the explosive ordnance 10 during the time delay of the means for fuse ignition 22.

[0029] According to another embodiment there is an arrangement for explosive ordnance clearing, wherein the explosive ordnance clearing device 20 comprises one of a visual marker 50 (Fig. 6a), and an optical guiding aid 51 (Fig. 6b). The ignition UAV 41 is guided into a position with the explosive ordnance clearing device 20 by one of a visual marker 50, and an optical guiding aid 51 in the explosive ordnance clearing device 20. It is common in the skill of the art that unmanned vehicles are equipped with cameras and a wireless data link for providing visual view to the operator of the ignition UAV 41 for manoeuvring the vehicle. The same camera 54 may be used for aiming the vehicle an exact position with respect to the explosive ordnance clearing device 20. The visual marker 50 comprises a pattern, which provides a reference measure of height and width for the operator. When the optical characteristic of the camera 54 of the ignition UAV 41 are known, it is possible to estimate the distance of the ignition UAV 41 via the visual view. The pattern of the visual marker 50 may also be used in estimating the orientation of the ignition UAV 41 with respect to the explosive ordnance clearing device 20. An image processing system in the ignition UAV 41 or at an operator control device may be used to estimate the distance and the orientation of the ignition UAV 41 with respect to the explosive ordnance clearing device 20. The operator control device is typically a device used for remote controlling an unmanned vehicle and it comprises a display for visual monitoring of the surroundings the unmanned vehicle. The image processing system may be used to automate the approach of the ignition UAV 41 to close proximity of the explosive ordnance clearing device 20, and the image processing system may be organised to provide control instructions to the ignition UAV 41 or assist the operator by giving manoeuvring guidance to the operator. Alternatively, instead of the visual marker 50, the explosive ordnance clearing device 20 may comprise an optical guidance aid 51 for guiding the ignition UAV 41 into a position with the explosive ordnance clearing device 20, wherein the optical guidance aid 51 comprises means for reflecting a light actuation such that an actuating light beam from the ignition UAV 41 is reflected by the optical guidance aid 51. One of a wavelength, intensity, and pattern of the reflected light is varied based on a tilt or the orientation of the light beam with respect to optical guidance aid 51.

[0030] According to another embodiment there is an arrangement for explosive ordnance clearing, wherein the ignition UAV 41 comprises means for detecting a detonation of the clearing explosive 21. Information of the detonation is transmitted wirelessly from the ignition UAV 41. The explosion detection may be performed by at least one of a microphone, the camera 54, and a pressure sensor in the ignition UAV 41. When a sound of the detection is performed by the microphone, the sound is transmitted wirelessly to the operator or information about the explosion is transmitted to an operator device. Alternatively, the ignition UAV 41 may comprise means for detecting a sound of explosion by comparing the microphone signal to pre-stored characteristic of an explosion and taking into account the distance of the ignition UAV 41 to the explosive ordnance clearing device 20. The distance may be estimated with the flight control data or by the visual information provided by the visual marker 50 or the visual guidance aid 51. Alternatively, the detection may be performed by the camera 54 of the ignition UAV 41 detecting a flash of the explosion and the transmitting the information of the explosion wirelessly to the operator device. Alternatively, the detection may be performed by the pressure sensor of the ignition UAV 41 detecting a change in pressure, which change exceeds a pre-stored threshold value.

[0031] According to another embodiment there is an arrangement for explosive ordnance clearing, wherein the ignition UAV 41 comprises means for wireless transmission of information of a detonation of the clearing explosive 21.

[0032] Referring to Figures 2 and 4, according to another embodiment there is an arrangement for explosive ordnance clearing, wherein the first conductor 27 comprises the first lead 25 and the second lead 26, and wherein the second conductor 45 comprises a third lead 46 and a fourth lead 47, wherein the third lead and the fourth lead 46, 47 are configured to provide an electric voltage, which is configured to ignite the means for fuse ignition 22 via the first lead 25 and the second lead 26, respectively. The first lead 25 and the second lead 26 may comprise folded sections 28, 29, respectively, which are configured to provide an easier contact surface for the third and fourth leads 46, 47, respectively. Preferably the folding of the sections 28, 29 is configured in a slightly upwards tilted attitude with respect to explosive ordnance clearing device 20. The tilted attitude and flexibility of sections 28, 29 enables easier detachment of the third and fourth leads 46, 47 in case the third and fourth leads 46, 47 would be placed under the sections 28, 29, respectively. The electric voltage is provided via the second conductor 45 to the first conductor 27 and further to the means for fuse ignition 22. The ignition UAV 41 comprises at least one of a battery 42 and a capacitor to store the electric charge. It is known in the art how to arrange an electric current enough to ignite a fuse ignition.

[0033] Referring to Figures 5 and 6c, according to another embodiment there is an arrangement 30 for explosive ordnance clearing, wherein a explosive ordnance clearing device 30 comprises a first conductor 37 and a slot 38 configured to receive the heat agent 44 to the means for fuse ignition 32. The ignition UAV 41 is configured to bring the heat agent 44 into close proximity of the explosive ordnance clearing device 30. The second conductor 48 of the ignition UAV 41 is guiding the heat agent 44 to the means for fuse ignition 32. The heat agent 44 may be released from the second conductor 48, or it may be brought only into contact with the first conductor 37.

[0034] According to another embodiment there is an arrangement for explosive ordnance clearing, wherein the slot 38 of the explosive ordnance clearing device 30 comprises an upwards facing opening 39 and a width larger than a diameter of the slot 38, which opening 39 is arranged to guide the heat agent 44 to the means for fuse ignition 32. The explosive ordnance clearing device 31 may also comprise one of a visual marker 50 and an optical guiding aid 51 as shown in Fig. 6c.

[0035] It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

CLAIMS1. A method for explosive ordnance clearing, comprising: transporting an explosive ordnance clearing device (20) to a close proximity of an explosive ordnance (10), wherein the explosive ordnance clearing device (20) comprises a clearing explosive (21), a detonator to detonate the clearing explosive (21), means for fuse ignition (22) to ignite the detonator, and a first conductor (27) connected to the means for fuse ignition (22); transporting one of an electric charge and a heat agent (44) to the close proximity of the explosive ordnance clearing device (20) with an ignition unmanned aerial vehicle (41), wherein the ignition unmanned aerial vehicle (41) comprises a second conductor (45); bringing one of the electric charge and the heat agent (44) into connection with the second conductor (45, 48) to the first conductor (27, 37) for igniting the means for fuse ignition (22). moving the ignition unmanned aerial vehicle 40 to a distance from the explosive ordnance (10).

2. A method according to claim 1, wherein the explosive ordnance clearing device (20) is transported to a close proximity of the explosive ordnance (10) with an unmanned vehicle.

3. A method according to claim 2, wherein the unmanned vehicle is one of the ignition unmanned aerial vehicle (41), a transport unmanned aerial vehicle (40), an unmanned surface vessel, and an unmanned ground vehicle.

4. A method according to any preceding claim, wherein the unmanned aerial vehicle (41) is guided into a position by at least one of a visual marker (50), and an optical guidance aid (51).

5. A method according to any preceding claim, wherein a detonation of the clearing explosive (21) is detected by one of a sound detector, a camera (54), and pressure sensor of the unmanned aerial vehicle (41), and information of the detonation is transmitted wirelessly from the unmanned aerial vehicle (41).

6. A method according to any preceding claim, wherein the first and second conductor (27, 45) are connecting the electric charge to the means for fuse ignition (22).

7. A method according to claim 5, wherein the electric charge is transported by at least one of a battery (42) and a capacitor.

8. A method according to any preceding claim 1-4, wherein the second conductor (48) is guiding the heat agent (44) to the means for fuse ignition (32).

9. A method according to any preceding claim, wherein in bringing the first conductor (37) into connection with the second conductor (48) for igniting the means for fuse ignition (32), at least one of the first and second conductor (48) is guiding the at least second and first conductor (37) into a contact, respectively.

10. An arrangement for explosive ordnance clearing, comprising: an explosive ordnance clearing device (20), wherein the explosive ordnance clearing device (20) comprises a clearing explosive (21), a detonator to detonate the clearing explosive (21), means for fuse ignition (22) to ignite the detonator, and a first conductor (27) connected to the means for fuse ignition (22); and an ignition device attached to an unmanned aerial vehicle, the ignition device comprising one of an electric charge container and a heat agent (44), and a second conductor (45, 48) for connecting the one of an electric charge container and a heat agent (44) to the first conductor (43).

11. An arrangement for explosive ordnance clearing according to claim 10, wherein the explosive ordnance clearing device (20) comprises at least one of a visual marker (50) and an optical guiding aid (51), and wherein the unmanned aerial vehicle comprises a camera (54) for assisting the unmanned aerial vehicle in approaching into aposition of contact for the first conductor (27) and the second conductor (45).

12. An arrangement for explosive ordnance clearing according to any preceding claim 10-11, wherein the unmanned aerial vehicle comprises means for detecting a detonation of the clearing explosive(21).

13. An arrangement for explosive ordnance clearing according to any preceding claim 10-12, wherein the unmanned aerial vehicle comprises means for wireless transmission of information of a detonation of the clearing explosive (21).

14. An arrangement for explosive ordnance clearing according to any preceding claim 10-13, wherein the first conductor (27) comprises a first lead (25) and a second lead (26), and wherein the second conductor (45) comprises a third lead (46) and a fourth lead (47), wherein the third lead (46) and the fourth lead (47) are configured to provide an electric voltage for igniting the means for fuse ignition(22) via the first lead (25) and the second lead (26), respectively.

15. An arrangement for explosive ordnance clearing according to claim 14, wherein the electric charge container of the ignition device comprises one of a battery (42) and a capacitor.

16. An arrangement for explosive ordnance clearing according to any preceding claim 10-13, wherein the first conductor (37) comprises a slot (38) configured to receive the heat agent (44) to the means for fuse ignition (32).

17. An arrangement for explosive ordnance clearing according to claim 16, wherein the slot (38) comprises an upwards facing opening (39) and a width larger than a diameter of the slot (38), which opening is arranged to guide the heat agent (44) to the means for fuse ignition

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