Unmanned aerial vehicle non-coplanar array type transient electromagnetic system for unexploded ordnance detection

Abstract

The invention provides an unmanned aerial vehicle non-coplanar array type transient electromagnetic system for unexploded ordnance detection. The unmanned aerial vehicle non-coplanar array type transient electromagnetic system comprises an unmanned aerial vehicle, a signal transmitting device and an array type receiving device. The signal transmitting device is fixedly arranged on a body of the unmanned aerial vehicle, the array type receiving device is arranged below the body of the unmanned aerial vehicle, and the array type receiving device is detachably and fixedly connected with the body of the unmanned aerial vehicle through a connecting mechanism; the unexploded ordnance detection method has the advantages of high maneuverability, high detection speed, high efficiency and no terrain limitation during unexploded ordnance detection, and the personnel safety risk can be effectively reduced; moreover, the transmitting coil and the receiving coil are not in the same plane, thereby reducing the mutual inductance between the transmitting coil and the receiving coil, highlighting the resolution of a superficial target body, effectively enlarging the detection range, and improving the detection accuracy and efficiency.

Description

Technical Field

[0001] This invention relates to an electromagnetic detection system, and more particularly to a non-coplanar array transient electromagnetic system for unexploded ordnance detection by unmanned aerial vehicles. Background Technology

[0002] Unexploded ordnance mainly refers to landmines, shells, grenades, bullets, and even missiles left behind after wars or other military activities that have not yet detonated. They are usually scattered on the surface or in very shallow underground locations, seriously threatening the safety of people's lives and property, and affecting economic and social development.

[0003] For the detection of unexploded ordnance (UFOs), the main methods include magnetic methods, ground-penetrating radar (GPR), and electromagnetic methods. Magnetic methods are easily affected by environmental and geological conditions, have poor anti-interference capabilities, low resolution in magnetic soils, and are insensitive to non-ferromagnetic targets. The detection results cannot reflect depth information, resulting in a high false alarm rate. GPR detection is easily affected by geological conditions, surface soil moisture content, and vegetation interference, and can only be used for further confirmation of UFOs after location. Electromagnetic methods are the most widely used in UFO detection. They utilize a transmitting coil to emit a pulsed electromagnetic field that excites an eddy current secondary field within the UFO target, and a receiving coil to receive the time-varying characteristics of this secondary field to detect the UFO target.

[0004] In existing technologies, electromagnetic methods for detecting unexploded ordnance are generally used in portable handheld and vehicle-mounted detection systems. Portable handheld systems require personnel to carry the equipment into the unexploded ordnance detection site, which poses a high risk of personnel casualties and low construction efficiency. Vehicle-mounted systems are only suitable for flat detection sites and are difficult to operate in shallow waters, swamps, mudflats, and complex terrains, resulting in poor terrain adaptability.

[0005] With technological advancements, airborne electromagnetic methods have gradually emerged. Airborne transient electromagnetic systems, primarily mounted on helicopter platforms, offer advantages such as high mobility, fast detection speed, high efficiency, and independence from terrain limitations, as exemplified by the Canadian VTEM system and the Danish SkyTEM system. The VTEM system employs a differential dual-receiver compensation device, connecting two sub-receiver coils in reverse series for compensation detection. While this device reduces the detection blind zone to some extent, it sacrifices the effective receiving area, limiting its acquisition to secondary field gradient information and reducing signal sensitivity. Furthermore, this device cannot achieve array-based detection. The SkyTEM system uses an eccentric device structure, placing the receiving coil at the edge of the transmitting coil to eliminate mutual inductance and reduce the detection blind zone. However, since its transmitting and receiving coils are on the same plane, signal quality is affected, reducing detection accuracy.

[0006] Therefore, a new technical approach is urgently needed to solve the above-mentioned technical problems. Summary of the Invention

[0007] In view of this, the purpose of this invention is to provide a non-coplanar array transient electromagnetic system for unexploded ordnance detection using a UAV. Based on the UAV as the platform, it can provide advantages such as high mobility, fast detection speed, high efficiency, and no terrain limitations in unexploded ordnance detection, and can effectively reduce personnel safety risks. Moreover, the transmitting coil and receiving coil are not on the same plane, which reduces the mutual inductance between the transmitting coil and receiving coil, improves the resolution of shallow targets, and can effectively increase the detection range, accuracy and efficiency of detection.

[0008] The present invention provides a non-coplanar array transient electromagnetic system for unexploded ordnance detection by a drone, comprising a drone, a signal transmitting device, and an array receiving device.

[0009] The signal transmitting device is fixedly installed on the body of the UAV, and the array receiving device is installed below the body of the UAV. The array receiving device is detachably and fixedly connected to the body of the UAV through a connecting mechanism.

[0010] Furthermore, the signal transmitting device includes a transmitting coil, a signal generating circuit, and a control host. The detection signal output by the signal generating circuit is applied to the transmitting coil, and the control host is used to control the operation of the signal generating circuit.

[0011] The transmitting coil is fixed to the body of the UAV by a bracket.

[0012] Furthermore, the signal generating circuit generates a bipolar trapezoidal wave with a duty cycle of 50% and applies it to the transmitting coil.

[0013] Furthermore, the array-type receiving device includes a receiving coil array and a receiving circuit. The output terminal of the receiving circuit is connected to the control host. The receiving circuit is used to process the detection signal output by the receiving coil array and then input it to the control host.

[0014] The receiving coil array includes multiple receiving coils and a mounting bracket. The receiving coils are fixedly mounted on the mounting bracket to form a planar array. The mounting bracket is connected to the body of the UAV via a connector. The receiving coil array is located below the UAV body.

[0015] Furthermore, it also includes a host computer, which is wirelessly connected to the control host.

[0016] Furthermore, the frequency of the bipolar trapezoidal wave generated by the signal generating circuit is 16Hz, and the sampling frequency of the detection signal output by the receiving circuit by the control host is 1.25MHz.

[0017] The beneficial effects of this invention are as follows: Based on the UAV as the platform, it can achieve the advantages of high mobility, fast detection speed, high efficiency and no terrain limitation when detecting unexploded ordnance, and can effectively reduce personnel safety risks; moreover, the transmitting coil and receiving coil are not on the same plane, which reduces the mutual inductance between the transmitting coil and receiving coil, improves the resolution of shallow targets, and can effectively improve the detection range, accuracy and efficiency of detection. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0019] Figure 1 This is a schematic diagram of the structure of the present invention.

[0020] Figure 2 This is an electrical schematic diagram of the present invention. Detailed Implementation

[0021] The present invention will be further described in detail below:

[0022] The present invention provides a non-coplanar array transient electromagnetic system for unexploded ordnance detection by a UAV, comprising a UAV 1, a signal transmitting device, and an array receiving device;

[0023] The signal transmitting device is fixedly mounted on the fuselage of the UAV 1, and the array receiving device is located below the fuselage of the UAV. The array receiving device is detachably and fixedly connected to the fuselage of the UAV via a connecting mechanism. The UAV is a multi-rotor UAV, which features high flexibility, easy operation, and high stability. Through the above structure, it can achieve the advantages of high mobility, fast detection speed, high efficiency, and no terrain restrictions when detecting unexploded ordnance, and can effectively reduce personnel safety risks. Moreover, the transmitting coil and the receiving coil are not on the same plane, which reduces the mutual inductance between the transmitting coil and the receiving coil, improves the resolution of shallow targets, and can effectively improve the detection range, accuracy, and efficiency.

[0024] In this embodiment, the signal transmitting device includes a transmitting coil 3, a signal generating circuit, and a control host 5. The detection signal output by the signal generating circuit is loaded onto the transmitting coil, and the control host is used to control the operation of the signal generating circuit.

[0025] The transmitting coil is fixed to the drone's body via a bracket. The transmitting coil is fixed to the drone's body via a transmitting coil bracket 2, and the transmitting coil is located above the drone's body. The signal generation circuit generates a bipolar trapezoidal wave with a 50% duty cycle, which is then applied to the transmitting coil, thus improving detection accuracy. In practice, a power supply is also provided, typically a lithium battery. This lithium battery can serve as the drone's power battery or can be configured separately. When configured separately, such as... Figure 1 In the attached diagram, reference numerals 6 and 7 indicate the platform set up on the UAV to carry the corresponding equipment; the signal generation circuit can use existing circuits.

[0026] In this embodiment, the array-type receiving device includes a receiving coil array and a receiving circuit. The output terminal of the receiving circuit is connected to the control host. The receiving circuit is used to process the detection signal output by the receiving coil array and then input it to the control host.

[0027] The receiving coil array includes multiple receiving coils 10 and a mounting bracket 9. The receiving coils are fixedly mounted on the mounting bracket to form a planar array. The mounting bracket is connected to the drone's body via connectors. The receiving coil array is located below the drone's body. By forming an array with multiple coils, the detection range can be increased, i.e., the detection corridor can be expanded, thereby improving detection efficiency and accuracy. The connectors can be existing rigid connectors, such as steel wire, or flexible connectors 8, such as nylon wire. The connectors are detachably fixed to the drone's body. If a rigid connector is used, it is fixed with bolts or screws. If a nylon wire is used, binding points can be set on the drone's body for securing it by binding and knotting. This detachable connection facilitates transportation when not in use for detection. The receiving circuit and signal generating circuit are integrated into a single structure. Figure 1 The mark in is 4.

[0028] In this embodiment, a host computer is also included. The host computer is wirelessly connected to the control host. The host computer and the control host communicate wirelessly via a Bluetooth 3.0 module. Alternatively, an existing UWB module can be used. The host computer, in conjunction with the data supercomputing cloud platform processing software, processes and images the detection data to more intuitively display the depth and horizontal position distribution of the detected target.

[0029] In this embodiment, the frequency of the bipolar trapezoidal wave generated by the signal generation circuit is 16Hz, and the sampling frequency of the detection signal output by the receiving circuit by the control host is 1.25MHz.

[0030] The drone's movement speed during detection was set to 1m / s-3m / s, and its altitude to 5m-20m.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A non-coplanar array-type transient electromagnetic system for unexploded ordnance detection by unmanned aerial vehicles, characterized in that: This includes drones, signal transmitters, and array receivers; The signal transmitting device is fixedly mounted on the body of the UAV, and the array receiving device is located below the body of the UAV. The array receiving device is detachably and fixedly connected to the body of the UAV through a connecting mechanism.

2. The UAV non-coplanar array transient electromagnetic system for unexploded ordnance detection according to claim 1, characterized in that: The signal transmitting device includes a transmitting coil, a signal generating circuit, and a control host. The detection signal output by the signal generating circuit is loaded onto the transmitting coil, and the control host is used to control the operation of the signal generating circuit. The transmitting coil is fixed to the body of the UAV by a bracket.

3. The UAV non-coplanar array transient electromagnetic system for unexploded ordnance detection according to claim 2, characterized in that: The signal generating circuit generates a bipolar trapezoidal wave with a duty cycle of 50% and applies it to the transmitting coil.

4. The UAV non-coplanar array transient electromagnetic system for unexploded ordnance detection according to claim 3, characterized in that: The array-type receiving device includes a receiving coil array and a receiving circuit. The output terminal of the receiving circuit is connected to the control host. The receiving circuit is used to process the detection signal output by the receiving coil array and then input it to the control host. The receiving coil array includes multiple receiving coils and a mounting bracket. The receiving coils are fixedly mounted on the mounting bracket to form a planar array. The mounting bracket is connected to the body of the UAV via a connector. The receiving coil array is located below the UAV body.

5. The UAV non-coplanar array transient electromagnetic system for unexploded ordnance detection according to claim 2, characterized in that: It also includes a host computer, which is wirelessly connected to the control host.

6. The UAV non-coplanar array transient electromagnetic system for unexploded ordnance detection according to claim 4, characterized in that: The frequency of the bipolar trapezoidal wave generated by the signal generation circuit is 16Hz, and the sampling frequency of the detection signal output by the receiving circuit by the control host is 1.25MHz.

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