Three-dimensional magnetic anomaly feature extraction method and system applied to unexploded ordnance identification

Abstract

The invention provides a three-dimensional magnetic anomaly feature extraction method and system applied to unexploded ordnance identification, and the method comprises the steps: rotating the angle of an unexploded ordnance, and adjusting the position of a first magnetometer relative to the unexploded ordnance; the data recording instrument records unexploded ordnance identification information and position data and angle data of the unexploded ordnance relative to the first magnetometer, and original magnetic anomaly data of the unexploded ordnance is obtained by combining the first magnetic data and a difference value of synchronously collected second magnetic data; performing inversion based on the original magnetic anomaly data and the position data of a plurality of positions corresponding to the same angle so as to form a three-dimensional point cloud model at the angle; and performing inversion based on the three-dimensional point cloud model of the multiple angles to form three-dimensional magnetic anomaly features. Multiple groups of original magnetic anomaly data of the unexploded ordnance are collected and inverted in the outdoor environment to form three-dimensional magnetic anomaly features capable of being compared and matched with actually measured data, and the efficiency, accuracy and convenience of unexploded ordnance detection are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of unexploded bomb identification, and particularly relates to a three-dimensional magnetic anomaly feature extraction method and system applied to unexploded bomb identification. BACKGROUND

[0002] An unexploded bomb is a bomb, mine, shell, missile and other weapons left in the natural environment without explosion. Since the unexploded bomb has the possibility of explosion, there is a great safety hazard. At present, the unexploded bomb is mainly detected by manual searching. The operating personnel need to wear heavy protective equipment such as helmets and bulletproof vests for carpet search, which has a large workload, high search requirements and high risk.

[0003] Aerial magnetic survey is a method of detecting unexploded bombs by measuring magnetic anomalies with a magnetometer carried by an aircraft. Compared with manual searching, aerial magnetic survey is safer, has high detection efficiency, low cost and large detection depth, and is commonly used to detect unexploded bombs underground or in water.

[0004] However, since the aerial magnetic survey has a large detection area and collects many data points, and the magnetic anomaly data of some magnetic materials is close to the magnetic survey data of the unexploded bomb, the traditional method cannot quickly identify the unexploded bomb, and there are problems of high false negative rate and high false positive rate. SUMMARY

[0005] The present application is proposed based on the above-mentioned needs of the prior art. The technical problem to be solved by the present application is to provide a three-dimensional magnetic anomaly feature extraction method and system applied to unexploded bomb identification. The method collects and inverts multiple sets of original magnetic anomaly data of unexploded bombs and corresponding identification information, position data and angle data in an outdoor environment to form three-dimensional magnetic anomaly features that can be compared and matched with actual measurement data, thereby improving the efficiency, accuracy and convenience of unexploded bomb detection.

[0006] In order to solve the above-mentioned problems, the present application provides the following technical solutions.

[0007] The present application provides a three-dimensional magnetic anomaly feature extraction method applied to unexploded bomb identification. The method is operated in an outdoor environment and includes the following steps: Step 1: In an outdoor environment, a first magnetometer and a second magnetometer are arranged near an unexploded bomb, and the first magnetometer and the second magnetometer are connected to a data collection instrument, respectively. Step 2: The angle of the unexploded bomb is rotated, and the positions of the first magnetometer and the second magnetometer relative to the unexploded bomb are adjusted. The first magnetometer collects first magnetic force data in real time, and the second magnetometer synchronously collects second magnetic force data in real time. Step 3: The data collection instrument records the unexploded bomb identification information and the position data and angle data of the unexploded bomb relative to the first magnetometer, and obtains the original magnetic anomaly data of the unexploded bomb by combining the difference between the first magnetic data and the second magnetic data collected synchronously; Step 4: Based on the original magnetic anomaly data and position data of the unexploded bomb at multiple positions corresponding to the same angle, inversion is performed to form a three-dimensional point cloud model of the unexploded bomb at any position corresponding to the original magnetic anomaly data at the angle. Step 5: Based on the three-dimensional point cloud models of the unexploded bomb at multiple angles, inversion is performed to form a three-dimensional magnetic anomaly feature containing a three-dimensional point cloud model of the unexploded bomb at any angle.

[0008] The application also provides a three-dimensional magnetic anomaly feature extraction system applied in the above method to extract the three-dimensional magnetic anomaly feature, comprising a first magnetometer, a proximal positioning assembly, a second magnetometer and a data collection instrument.

[0009] Further, the three-axis sliding support comprises a mounting frame, two first sliding rods which are respectively slidably connected with two side support vertical rods of the mounting frame, a second sliding rod which is arranged between the two first sliding rods and is slidably connected with the first sliding rods, a sliding seat which is slidably connected with the second sliding rod, and the first magnetometer and the second magnetometer are fixedly arranged on the sliding seat.

[0010] Further, the first sliding rod is guided and driven by a first ball screw driven by the first non-magnetic motor, the second sliding rod is guided and driven by a second ball screw driven by the second non-magnetic motor, and the sliding seat is guided and driven by a third ball screw driven by the third non-magnetic motor.

[0011] Further, the rotating platform comprises a base, a first rotating seat rotationally connected with the base through a first rotating shaft, and an axis of the first rotating shaft is parallel to the first slide rod, a second rotating seat rotationally connected with the first rotating seat through a second rotating shaft, and the unexploded bomb is arranged above the second rotating seat, and an axis of the second rotating shaft is parallel to the second slide rod in an initial state.

[0012] Further, the three-axis sliding support and the rotating platform are made of non-magnetic materials.

[0013] Further, the first magnetometer, the mounting frame, the first slide rod, the second slide rod, the slide seat, the first non-magnetic motor, the first ball screw, the second non-magnetic motor, the second ball screw, the third non-magnetic motor, the third ball screw, and the positioner are detachably connected structures.

[0014] Further, the first magnetometer and the second magnetometer are arranged in a vertical direction, or the first magnetometer and the second magnetometer are arranged in a horizontal direction.

[0015] Further, the first magnetometer and the second magnetometer are both vector optical pump magnetometers.

[0016] The beneficial effects of the present application include: (1) The three-dimensional magnetic anomaly feature extraction method of the present application can collect and invert multiple sets of original magnetic anomaly data of unexploded bombs and corresponding identification information, position data and angle data in an outdoor environment to form a three-dimensional magnetic anomaly feature containing a three-dimensional point cloud model of the unexploded bomb at any angle. The three-dimensional magnetic anomaly feature can match the measured data of the unexploded bomb at any position and angle, and through comparison and identification with the measured data, the magnetic survey data of the unexploded bomb can be quickly found in a large amount of data of the aerial magnetic survey, the unexploded bomb can be accurately positioned and excluded, and the efficiency, accuracy and convenience of the unexploded bomb detection are improved.

[0017] (2) The original magnetic anomaly data collected in the real outdoor environment by using the system and method of the present application can reduce the influence of complex environmental variables on the detection result, and can use real unexploded bombs for sampling without relying on laboratory models, which is beneficial to improve the accuracy of the original magnetic anomaly data and improve the accuracy of the unexploded bomb detection.

[0018] (3) The three-dimensional magnetic anomaly feature extraction system proposed by the present application can conveniently obtain the original magnetic anomaly data of the unexploded bomb at multiple angles and multiple positions in an outdoor environment, extract the three-dimensional magnetic anomaly feature based on the above method, and improve the convenience of the unexploded bomb detection. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present specification, the drawings required to be used in the specific embodiments will be briefly introduced below. Obviously, the drawings described below are only some specific embodiments described in the present specification, and other drawings can also be obtained by those skilled in the art according to these drawings.

[0020] Figure 1 is a flowchart of the three-dimensional magnetic anomaly feature extraction method of the invention; Figure 2 is a flowchart of the use of the extracted three-dimensional magnetic anomaly feature to identify unexploded bombs in the specific embodiments; Figure 3 is a structural diagram of the proximal positioning assembly of the three-dimensional magnetic anomaly feature extraction system of the invention; Figure 4 is a connection structure diagram of the three-axis sliding support and the first magnetometer and the second magnetometer when the first magnetometer is suspended below the second magnetometer in the three-dimensional magnetic anomaly feature extraction system of the invention; Figure 5 is a local structural diagram of the three-axis sliding support of the three-dimensional magnetic anomaly feature extraction system of the invention; Figure 6 is a connection structure diagram of the rotating platform and the unexploded bomb in the three-dimensional magnetic anomaly feature extraction system of the invention; Figure 7 is a connection diagram of the data collection instrument and the first magnetometer, the second magnetometer, and the positioner in the three-dimensional magnetic anomaly feature extraction system of the invention.

[0021] Reference signs: 1000, first magnetometer; 1100, optical unit; 1200, electronic unit; 2000, proximal positioning assembly; 2100, three-axis sliding support; 2101, mounting frame; 2102, support vertical rod; 2103, first sliding rod; 2104, second sliding rod; 2105, sliding seat; 2106, first non-magnetic motor; 2107, first ball screw; 2108, second non-magnetic motor; 2109, second ball screw; 2110, third non-magnetic motor; 2111, third ball screw; 2112, positioner; 2200, rotating platform; 2201, base; 2202, first rotating seat; 2203, first rotating shaft; 2204, second rotating seat; 2205, second rotating shaft; 2206, locking nut; 3000, second magnetometer; 4000, data collection instrument; 5000, unexploded bomb. Specific embodiments

[0022] The technical solutions in the embodiments of the present invention will now be clearly and completely described in conjunction with the accompanying drawings. Obviously, the embodiments described in this invention are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of this invention.

[0023] To rapidly identify unexploded ordnance 5000 from a large amount of airborne magnetic survey data, and to accurately locate and exclude unexploded ordnance 5000, this specific embodiment proposes a three-dimensional magnetic anomaly feature extraction method for unexploded ordnance identification, including, as follows: Figure 1 The following steps are shown: Step 1: In an outdoor environment, set up a first magnetometer 1000 and a second magnetometer 3000 near the unexploded ordnance 5000, and connect the first magnetometer 1000 and the second magnetometer 3000 to the data recorder 4000 respectively. Step 2: Rotate the angle of the unexploded ordnance 5000 and adjust the positions of the first magnetometer 1000 and the second magnetometer 3000 relative to the unexploded ordnance 5000. The first magnetometer 1000 collects the first magnetic data in real time, and the second magnetometer 3000 collects the second magnetic data in real time simultaneously. Step 3: The data recorder 4000 records the unexploded ordnance identification information and the position and angle data of the unexploded ordnance 5000 relative to the first magnetometer 1000, and obtains the original magnetic anomaly data of the unexploded ordnance 5000 by combining the difference between the first magnetic data and the synchronously acquired second magnetic data. Step 4: Based on the original magnetic anomaly data and position data of the unexploded ordnance 5000 at multiple positions corresponding to the same angle, perform inversion to form a three-dimensional point cloud model of the correspondence between the unexploded ordnance 5000 at any position at that angle and the original magnetic anomaly data. Step 5: Invert the three-dimensional point cloud model of the unexploded ordnance 5000 at multiple angles to form a three-dimensional magnetic anomaly feature that includes the three-dimensional point cloud model of the unexploded ordnance 5000 at any angle.

[0024] The three-dimensional magnetic anomaly feature extraction method described in this embodiment can form a three-dimensional magnetic anomaly feature containing a three-dimensional point cloud model of the unexploded ordnance 5000 at any angle by collecting and inverting multiple sets of original magnetic anomaly data of the unexploded ordnance 5000 in an outdoor environment, along with its corresponding identification information, location data, and angle data. This three-dimensional magnetic anomaly feature can be matched with the measured data of the unexploded ordnance 5000 at any position and angle. By comparing and identifying with the measured data, the magnetic measurement data of the unexploded ordnance 5000 can be quickly found in a large amount of airborne magnetic measurement data, accurately locating and excluding the unexploded ordnance 5000, thus improving the efficiency, accuracy, and convenience of unexploded ordnance 5000 detection.

[0025] The three-dimensional magnetic anomaly features include a three-dimensional point cloud model of the correspondence between the unexploded ordnance 5000 at any angle and at any position and the original magnetic anomaly data. Therefore, the three-dimensional magnetic anomaly features contain the original magnetic anomaly data of the unexploded ordnance 5000 at any angle and at any position, which can effectively match and identify with the measured data, further improving the accuracy and convenience of unexploded ordnance 5000 detection.

[0026] It should be noted that because laboratories cannot fully simulate complex outdoor environments—for example, environmental variables such as soil composition, humidity, temperature changes, vegetation cover, and geological activity cannot be completely identical to those in the outdoor environment—there will always be a certain deviation between the raw magnetic anomaly data of unexploded ordnance 5000 collected in the laboratory and the measured data. Therefore, this specific implementation method collects raw magnetic anomaly data in a real outdoor environment. This not only eliminates the influence of complex environmental variables on the detection results, but also allows the use of a real unexploded ordnance 5000 in the outdoor environment, without relying on a laboratory model. This is beneficial to improving the accuracy of the raw magnetic anomaly data, and further improves the accuracy of unexploded ordnance 5000 detection.

[0027] In practical applications, specifically when using the three-dimensional magnetic anomaly feature extraction method described in this embodiment to identify unexploded ordnance, the specific steps are as follows: Step S01: The aircraft conducts outdoor environmental surveys to simultaneously collect third magnetic data, fourth magnetic data, and measured position data.

[0028] Step S02: Based on the difference between the third magnetic data and the synchronously acquired fourth magnetic data, obtain the measured magnetic anomaly data.

[0029] Step S03: Extract the original magnetic anomaly data and unexploded ordnance identification information corresponding to the measured location data from the three-dimensional magnetic anomaly features, and compare the original magnetic anomaly data and the measured magnetic anomaly data corresponding to the measured location data.

[0030] Step S04: If the original magnetic anomaly data and the measured magnetic anomaly data match, then associate the measured magnetic anomaly data with the unexploded ordnance identification information.

[0031] Specifically, in the process of identifying unexploded ordnance (UPO) 5000, measured magnetic anomaly data can be calculated using data processing equipment such as PCs and servers. Then, the measured location data corresponding to the measured magnetic anomaly data is extracted. Next, the data processing equipment calculates the original magnetic anomaly data corresponding to the measured location data in each 3D point cloud model, and compares the measured magnetic anomaly data with all the original magnetic anomaly data. If the difference between the measured magnetic anomaly data and the original magnetic anomaly data does not exceed a threshold, they are considered a match, and the measured magnetic anomaly data is considered to be the magnetic anomaly data of UPO 5000. The measured magnetic anomaly data is then associated with the UPO identification information, thereby quickly and accurately identifying UPO 5000.

[0032] To facilitate the collection of multiple sets of raw magnetic anomaly data of unexploded ordnance 5000 and their corresponding position and angle data in outdoor environments, and to extract the three-dimensional magnetic anomaly features of unexploded ordnance 5000 based on the three-dimensional magnetic anomaly feature extraction method of this embodiment, this embodiment proposes a three-dimensional magnetic anomaly feature extraction system.

[0033] like Figures 3-7 As shown, the three-dimensional magnetic anomaly feature extraction system of this embodiment includes a first magnetometer 1000, a proximal positioning component 2000, a second magnetometer 3000, and a data recorder 4000.

[0034] The proximal positioning component 2000 includes a three-axis sliding bracket 2100 and a rotating platform 2200. A first magnetometer 1000 and a second magnetometer 3000 are mounted on the three-axis sliding bracket 2100 and positioned in three mutually orthogonal directions corresponding to the three-axis sliding bracket 2100. The positions of the first magnetometer 1000 and the second magnetometer 3000 are adjustable to adjust the position of the first magnetometer 1000 relative to the unexploded ordnance 5000 according to sampling requirements. The unexploded ordnance 5000 is mounted on the rotating platform 2200 and can rotate via the rotating platform 2200 to adjust the angle of the unexploded ordnance 5000 relative to the first magnetometer 1000 according to sampling requirements.

[0035] The types of the first magnetometer 1000 and the second magnetometer 3000 include vector optically pumped magnetometers, scalar optically pumped magnetometers, single-axis fluxgate magnetometers, dual-axis fluxgate magnetometers, and tri-axis fluxgate magnetometers. In specific implementations, the first magnetometer 1000 and the second magnetometer 3000 can be vector optically pumped magnetometers. Compared with fluxgate magnetometers, vector optically pumped magnetometers have higher sensitivity and can more effectively identify the magnetic field information of unexploded ordnance 5000. Furthermore, compared with scalar optically pumped magnetometers, vector optically pumped magnetometers can measure magnetic field components in different directions, thereby comparing and identifying the original magnetic measurement data with the measured data in multiple dimensions. Specifically, the first magnetometer 1000 is a cesium optically pumped magnetometer, including an electronic unit 1200 fixedly mounted on a triaxial sliding bracket 2100, and an optical unit 1100 located below the electronic unit 1200, which are connected by a cable.

[0036] The first magnetometer 1000 and the second magnetometer 3000 are positioned close to the unexploded ordnance 5000. In one embodiment, the first magnetometer 1000 is suspended below the second magnetometer 3000, and the two are vertically spaced apart. The distance between the first magnetometer 1000 and the unexploded ordnance 5000 can vary within the range of 0 to 10 meters. Because the first magnetometer 1000 and the second magnetometer 3000 are vertically spaced apart, by calculating the difference between the magnetic data of the first magnetometer 1000 and the magnetic data of the second magnetometer 3000, the influence of geomagnetic diurnal variations on the detection results can be effectively eliminated, and more accurate original magnetic anomaly data of the unexploded ordnance 5000 can be obtained. In another embodiment, the first magnetometer 1000 and the second magnetometer 3000 are arranged at intervals along the horizontal direction. By calculating the difference between the magnetic data of the first magnetometer 1000 and the magnetic data of the second magnetometer 3000, the influence of geomagnetic diurnal variation and other factors on the detection results is eliminated.

[0037] The data recorder 4000 is simultaneously connected to the first magnetometer 1000 and the second magnetometer 3000. When the unexploded ordnance 5000 rotates to multiple angles and the first magnetometer 1000 and the second magnetometer 3000 move synchronously to multiple positions, the first magnetometer 1000 collects first magnetic data, the second magnetometer 3000 synchronously collects second magnetic data, and the data recorder 4000 records the unexploded ordnance identification information, as well as the position and angle data of the unexploded ordnance 5000 relative to the first magnetometer 1000. The data recorder 4000 can invert and form a three-dimensional point cloud model of the unexploded ordnance 5000 at the same angle based on the original magnetic anomaly data and position data of the unexploded ordnance 5000 at multiple positions corresponding to the same angle, and invert and form three-dimensional magnetic anomaly features based on the three-dimensional point cloud model of the unexploded ordnance 5000 at multiple angles.

[0038] Based on the above-mentioned three-dimensional magnetic anomaly feature extraction system, it is possible to conveniently acquire raw magnetic anomaly data of unexploded ordnance 5000 at multiple angles and locations in outdoor environments, and extract three-dimensional magnetic anomaly features based on the above method, thereby improving the convenience of unexploded ordnance 5000 detection.

[0039] Specifically, the structure of the three-axis sliding support 2100 is as follows: Figure 4 and Figure 5 As shown. The three-axis sliding bracket 2100 includes a mounting frame 2101, a first slide rod 2103, a second slide rod 2104, a slide block 2105, a first non-magnetic motor 2106, a first ball screw 2107, a second non-magnetic motor 2108, a second ball screw 2109, a third non-magnetic motor 2110, a third ball screw 2111, and a positioner 2112.

[0040] The mounting frame 2101 is set on the ground. There are two first slide rods 2103, each slidably connected to the two supporting uprights 2102 on either side of the mounting frame 2101. A second slide rod 2104 is located between the two first slide rods 2103 and slidably connected to the first slide rods 2103. A slide block 2105 is slidably connected to the second slide rod 2104, and a first magnetometer 1000 and a second magnetometer 3000 are mounted on the slide block 2105. A first non-magnetic motor 2106 is connected to the first slide rod 2103 via a first ball screw 2107 arranged along the direction of the supporting upright 2102, driving the first slide rod 2103 to slide up and down along the supporting upright 2102. A second non-magnetic motor 2108 is connected to the second slide rod 2104 via a second ball screw 2109 arranged along the length direction of the first slide rod 2103, driving the second slide rod 2104 to slide back and forth relative to the length direction of the first slide rod 2103. The third non-magnetic motor 2110 is connected to the slide block 2105 via a third ball screw 2111 arranged along the second slide rod 2104, driving the slide block 2105 to slide back and forth along the second slide rod 2104. The positioner 2112 is simultaneously connected to the first non-magnetic motor 2106, the second non-magnetic motor 2108, and the third non-magnetic motor 2110 to set the position data of the first magnetometer 1000 relative to the unexploded ordnance 5000 in three sliding directions. These three directions are mutually orthogonal.

[0041] In practice, the position of the first magnetometer 1000 relative to the unexploded ordnance 5000 can be adjusted by manually sliding the first slide bar 2103, the second slide bar 2104, and the slide block 2105. For example, the three-axis sliding bracket 2100 does not include the first non-magnetic motor 2106, the second non-magnetic motor 2108, and the third non-magnetic motor 2110. The surfaces of the first ball screw 2107, the second ball screw 2109, and the third ball screw 2111 are smooth and do not have external threads. The support rod 2102, the first slide bar 2103, and the second slide bar 2104 are all equipped with scale markings. The position of the first magnetometer 1000 relative to the unexploded ordnance 5000 can be adjusted by sliding the first slide bar 2103, the second slide bar 2104, and the slide block 2105.

[0042] However, since highly realistic 3D point cloud models require inversion based on a large amount of sufficient original magnetic anomaly data, in the actual process of extracting 3D magnetic anomaly features, when the unexploded bomb 5000 is at an angle, the position of the first magnetometer 1000 needs to be adjusted dozens or even hundreds of times in each direction. The total number of times the position of the first magnetometer 1000 is adjusted can reach tens of thousands of times. Not only is the amount of operation huge, but the data recording is also very difficult. As a result, the above method of adjusting the position of the first magnetometer 1000 relative to the unexploded bomb 5000 is theoretically feasible, but its practicality is poor.

[0043] Therefore, in this specific embodiment, the three-axis sliding support 2100 includes a first non-magnetic motor 2106, a first ball screw 2107, a second non-magnetic motor 2108, a second ball screw 2109, a third non-magnetic motor 2110, a third ball screw 2111, and a positioner 2112. The positioner 2112 can set the position data of the first magnetometer 1000 relative to the unexploded ordnance 5000 in three orthogonal directions, so as to realize automatic and precise control of the relative position of the first magnetometer 1000 and the unexploded ordnance 5000. The positioner 2112 can also send its set position data to the data processing device, thereby reducing the difficulty of data recording, improving the efficiency and reliability of extracting three-dimensional magnetic anomaly features, and enhancing the practicality of the three-dimensional magnetic anomaly feature extraction system.

[0044] When the triaxial sliding support 2100 and the rotating platform 2200 are made of magnetic materials such as iron and nickel, they will generate an additional magnetic field, which will interfere with the magnetic data collected by the first magnetometer 1000. Therefore, in this specific embodiment, the triaxial sliding support 2100 and the rotating platform 2200 are made of non-magnetic materials such as aluminum alloy, titanium alloy, plastic, and ceramic to reduce interference with the magnetic data collected by the first magnetometer 1000 and further improve the accuracy of unexploded ordnance 5000 detection.

[0045] To facilitate the use of the three-dimensional magnetic anomaly feature extraction system in outdoor environments, the first magnetometer 1000, mounting frame 2101, first slide bar 2103, second slide bar 2104, slide block 2105, first non-magnetic motor 2106, first ball screw 2107, second non-magnetic motor 2108, second ball screw 2109, third non-magnetic motor 2110, third ball screw 2111, and positioner 2112 are all detachable connection structures.

[0046] like Figure 3 and Figure 5 In this specific embodiment, the mounting frame 2101 includes a lower support and a support pole 2102.

[0047] The lower support consists of four hollow flat tubes, each 5 meters long. Every two hollow flat tubes are fixed together with screws to form two 10-meter hollow flat tubes. The two hollow flat tubes are arranged parallel to each other, with a 10-meter gap between them on the left and right sides, and are connected into one unit by six 10-meter-long reinforcing connecting rods.

[0048] The support column 2102 includes eight hollow square tubes, each 6 meters long, and two first ball screws 2107, each 6 meters long. Four hollow square tubes and one first ball screw 2107 are respectively mounted on two parallel hollow flat tubes at both ends of the lower support. The bottom ends of the hollow square tubes and the bottom of the first non-magnetic motor 2106 are fixedly connected to the hollow flat tubes with screws. The output end of the first non-magnetic motor 2106 is connected to the bottom end of the first ball screw 2107 to drive the first ball screw 2107 to rotate. A guide strip is provided on one side of the support column 2102 to guide the first sliding rod 2103 to slide smoothly up and down.

[0049] The first slide rod 2103 comprises two hollow square tubes, each 10 meters in length. One side of the first slide rod 2103 has a groove that matches the guide strip of the supporting column 2102. The first slide rod 2103 is threadedly connected to the first ball screw 2107. When the first non-magnetic motor 2106 drives the first ball screw 2107 to rotate, the first ball screw 2107 can drive the first slide rod 2103 to move along the direction of the supporting column 2102, thereby adjusting the position data of the first magnetometer 1000 relative to the unexploded ordnance 5000 in the height direction. The other side of the first slide rod 2103 has a guide strip extending along its length. The second non-magnetic motor 2108 is fixedly mounted to one end of the first slide rod 2103 with screws.

[0050] The second slide rod 2104 includes a hollow square tube with a length of 10 meters. Both ends of the second slide rod 2104 have grooves that match the guide bars of the first slide rod 2103. The second slide rod 2104 is threadedly connected to the second ball screw 2109. When the second non-magnetic motor 2108 drives the second ball screw 2109 to rotate, the second ball screw 2109 can drive the second slide rod 2104 to move along the length of the first slide rod 2103, thereby adjusting the position data of the first magnetometer 1000 relative to the unexploded ordnance 5000 in a horizontal direction. The second slide rod 2104 has a guide groove extending along its length. The third non-magnetic motor 2110 is fixedly mounted on one end of the second slide rod 2104 by screws.

[0051] The slide block 2105 includes a slider slidably connected to the guide groove of the second slide rod 2104. The top of the slider is threadedly connected to the third ball screw 2111, and the bottom of the slider passes through the second slide rod 2104 and is fixedly connected to the mounting plate by screws. The electronic unit 1200 of the first magnetometer 1000 is fixedly connected to the mounting plate by screws. When the third non-magnetic motor 2110 drives the third ball screw 2111 to rotate, the third ball screw 2111 can drive the slide block 2105 to move along the direction of the second slide rod 2104 to adjust the position data of the first magnetometer 1000 relative to the unexploded ordnance 5000 in another horizontal direction.

[0052] Because the multiple components constituting the triaxial sliding bracket 2100 are detachably connected, the triaxial sliding bracket 2100 can be large in size while also being easy to disassemble, assemble, and transport, making it more suitable for various complex outdoor environments and further enhancing the practicality of the three-dimensional magnetic anomaly feature extraction system.

[0053] Furthermore, the triaxial sliding support 2100 may also include a top mount. For example, the top mount adopts the same structure as the base, also including four 5-meter-long hollow flat tubes and six 10-meter-long reinforcing connecting rods. The top ends of the eight supporting uprights 2102 are fixedly connected to the hollow flat tubes of the top mount by screws, and the top end of the first ball screw 2107 is rotatably connected to the hollow flat tubes by bearings. The top mount helps to prevent the entire triaxial sliding support 2100 from deforming, improving its structural stability.

[0054] like Figure 6 As shown, in this specific embodiment, the rotating platform 2200 includes a base 2201, a first rotating seat 2202, and a second rotating seat 2204.

[0055] The first rotating seat 2202 is positioned above the base 2201 and is rotatably connected to the base 2201 via a first rotating shaft 2203, the axis of which is parallel to the first sliding rod 2103. The second rotating seat 2204 is rotatably connected to the first rotating seat 2202 via a second rotating shaft 2205. The unexploded ordnance 5000 is positioned above the second rotating seat 2204, the axis of which is parallel to the second sliding rod 2104.

[0056] Specifically, the base 2201 includes four feet in contact with the ground and a platform above the feet. Two protrusions are welded to the upper surface of the platform, spaced a certain distance apart. A first rotating seat 2202 is positioned above the base 2201 and between the two protrusions. A first rotating shaft 2203 is located at the bottom of the base 2201, with both ends of the shaft passing through the two protrusions to achieve a rotatable connection between the first rotating seat 2202 and the base 2201. This allows adjustment of the angle of the unexploded ordnance 5000 using the first rotating shaft 2203 as the axis of rotation. Locking nuts 2206, threadedly connected to the first rotating shaft 2203, are located on both sides of the protrusions. When the locking nuts 2206 are tightened, the angle of the first rotating seat 2202 relative to the base 2201 is locked. The second rotating seat 2204 is disposed above the first rotating seat 2202. The top of the first rotating seat 2202 is provided with a cylindrical groove, and the bottom of the second rotating seat 2204 is provided with a matching second rotating shaft 2205 that can rotate relative to the second rotating seat 2204, so as to realize the rotational connection between the second rotating seat 2204 and the first rotating seat 2202, thereby adjusting the angle of the unexploded ordnance 5000 with the second rotating shaft 2205 as the rotation axis.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for extracting three-dimensional magnetic anomaly features for unexploded ordnance identification, characterized in that, To operate in an outdoor environment, the following steps are included: Step 1: In an outdoor environment, set up a first magnetometer (1000) and a second magnetometer (3000) near the unexploded ordnance (5000), and connect the first magnetometer (1000) and the second magnetometer (3000) to the data recorder (4000) respectively. Step 2: Rotate the angle of the unexploded ordnance (5000) and adjust the positions of the first magnetometer (1000) and the second magnetometer (3000) relative to the unexploded ordnance (5000). The first magnetometer (1000) collects the first magnetic data in real time, and the second magnetometer (3000) collects the second magnetic data in real time simultaneously. Step 3: The data recorder (4000) records the unexploded ordnance identification information and the position and angle data of the unexploded ordnance (5000) relative to the first magnetometer (1000), and obtains the original magnetic anomaly data of the unexploded ordnance (5000) by combining the difference between the first magnetic data and the synchronously acquired second magnetic data. Step 4: Based on the original magnetic anomaly data and position data of the unexploded ordnance (5000) at multiple positions corresponding to the same angle, perform inversion to form a three-dimensional point cloud model of the correspondence between the unexploded ordnance (5000) at any position and the original magnetic anomaly data at that angle; Step 5: Invert the three-dimensional point cloud model of the unexploded ordnance (5000) at multiple angles to form a three-dimensional magnetic anomaly feature containing the three-dimensional point cloud model of the unexploded ordnance (5000) at any angle.

2. A three-dimensional magnetic anomaly feature extraction system, applied to the extraction of three-dimensional magnetic anomaly features as described in claim 1, characterized in that, The device includes a first magnetometer (1000), a proximal positioning component (2000), a second magnetometer (3000), and a data recorder (4000). The proximal positioning component (2000) includes a three-axis sliding bracket (2100) and a rotating platform (2200). The first magnetometer (1000) and the second magnetometer (3000) are mounted on the three-axis sliding bracket (2100) and are located in three mutually orthogonal directions corresponding to the three-axis sliding bracket (2100). The positions of the first magnetometer (1000) and the second magnetometer (3000) relative to the unexploded ordnance (5000) are adjustable. The unexploded ordnance (5000) is mounted on the rotating platform, and the angle of the unexploded ordnance (5000) relative to the first magnetometer (1000) is adjustable.

3. The three-dimensional magnetic anomaly feature extraction system according to claim 2, characterized in that, The triaxial sliding support (2100) includes: Mounting frame (2101); There are two first slide rods (2103), which are slidably connected to the two side support rods (2102) of the mounting frame (2101); The second slide bar (2104) is disposed between the two first slide bars (2103) and is slidably connected to the first slide bars (2103); The slide block (2105) is slidably connected to the second slide rod (2104), and the first magnetometer (1000) and the second magnetometer (3000) are fixedly mounted on the slide block (2105). A first non-magnetic motor (2106) is used to drive the first slide bar (2103) to slide up and down along the support column (2102) of the mounting frame (2101); The second non-magnetic motor (2108) is used to drive the second slide bar (2104) to slide along the length direction of the first slide bar (2103); A third non-magnetic motor (2110) is used to drive the slide (2105) to slide along the second slide rod (2104); The locator (2112) is connected to the first non-magnetic motor (2106), the second non-magnetic motor (2108), and the third non-magnetic motor (2110) to set the position data of the first magnetometer (1000) relative to the unexploded ordnance (5000) in three sliding directions.

4. The three-dimensional magnetic anomaly feature extraction system according to claim 3, characterized in that, The first slide bar (2103) is guided and driven by the first ball screw (2107) driven by the first non-magnetic motor (2106); The second slide bar (2104) is guided and driven by a second ball screw (2109) driven by the second non-magnetic motor (2108); The slide (2105) is guided by a third ball screw (2111) driven by the third non-magnetic motor (2110).

5. The three-dimensional magnetic anomaly feature extraction system according to claim 4, characterized in that, The rotating platform (2200) includes: Base (2201); The first rotating seat (2202) is rotatably connected to the base (2201) via the first rotating shaft (2203), and the axis of the first rotating shaft (2203) is parallel to the first sliding rod (2103); The second rotating seat (2204) is rotatably connected to the first rotating seat (2202) via the second rotating shaft (2205). The unexploded ordnance (5000) is disposed above the second rotating seat (2204), and in the initial state, the axis of the second rotating shaft (2205) is parallel to the second slide bar (2104).

6. The three-dimensional magnetic anomaly feature extraction system according to claim 5, characterized in that, Both the triaxial sliding bracket (2100) and the rotating platform (2200) are made of non-magnetic materials.

7. The three-dimensional magnetic anomaly feature extraction system according to claim 4, characterized in that, The first magnetometer (1000), the mounting frame (2101), the first slide bar (2103), the second slide bar (2104), the slide block (2105), the first non-magnetic motor (2106), the first ball screw (2107), the second non-magnetic motor (2108), the second ball screw (2109), the third non-magnetic motor (2110), the third ball screw (2111), and the positioner (2112) are all detachable connection structures.

8. The three-dimensional magnetic anomaly feature extraction system according to claim 2, characterized in that, The first magnetometer (1000) and the second magnetometer (3000) are arranged at intervals in the vertical direction, or the first magnetometer (1000) and the second magnetometer (3000) are arranged at intervals in the horizontal direction.

9. The three-dimensional magnetic anomaly feature extraction system according to claim 2, characterized in that, Both the first magnetometer (1000) and the second magnetometer (3000) are vector optical pump magnetometers.

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