Passive electric field detection system and method for directional measurement of projectile

Abstract

The invention provides a passive electric field detection system and a passive electric field detection method for projectile directional measurement, which are mainly used for being arranged at the top of a vehicle, sensing target attack through an electric field sensor, resolving target orientation and providing early warning. Comprising an electric field sensor, a sub-sensor support, a tetrakaidecahedron connector, a main sensor support and a fixed base. When an attacking projectile passes through the electric field sensor array, the six orthogonal electric field sensors and the reference electric field sensor convert an electrostatic field generated by the attacking projectile into voltage signals; and the main control module resolves the signals of the electric field sensor array into the azimuth angle and the pitch angle of the incoming projectile through a resolving equation, so that the directional measurement of the incoming projectile is realized. According to the invention, electrostatic signals of gunpowder launched projectiles with various calibers in the flying process can be detected, the actual incoming attack direction of the projectiles can be calculated, and meanwhile, the device can be combined with an acoustic sensing technology, an infrared sensing technology and the like to improve the detection precision of a target.

Description

Technical Field

[0001] The present invention belongs to electric field detection technology, and in particular relates to a passive electric field detection system and method for projectile orientation measurement. Background Art

[0002] At present, acoustic sensor arrays, infrared optical systems, etc. are usually used for sniper positioning. Acoustic shooting detection and positioning systems mainly rely on two different sound waves generated by small arms when firing: muzzle shock wave and Mach wave. A "sniper trajectory acoustic measurement method" is disclosed in publication number CN102243041B. Microphone arrays are formed by randomly arranging and fixing three regular tetrahedron 4-element arrays. The trajectory equation is solved with the ballistic shock wave. However, under high background noise, the effectiveness of the acoustic sensor array will drop sharply. At the same time, the acoustic sensor is facing the application of silencers and subsonic bullets and the reflection conditions of urban and mountainous environments to the sound source. Its detection rate and measurement reliability to the projectile will be reduced. Infrared detection is to determine the enemy sniper position by detecting the infrared signal of the muzzle flash or the flying projectile and tracing back to the launch point. In the article "Analysis of the Effective Range of Bullet Radiation Detection System Using Multiple Infrared Sight Models", Liu Mingqi analyzed the effective range formula of bullets for a sniper position detection system that uses the infrared radiation trajectory of bullets to detect and trace the source, taking into account the absorption and scattering effects of the atmosphere on infrared radiation and the imaging model of bullets. The model analysis shows that the detection system can detect bullet radiation outside the rifle range. Infrared sensor systems have high requirements for their minimum detectable temperature difference, minimum resolvable temperature difference and frame rate in projectile detection. They are expensive and will also be affected by the environment and flash. They are usually used in conjunction with acoustic sensor systems for target search or warning. The electric field sensor system is a passive system. The electric field sensor array can be integrated with the acoustic sensor array to achieve better detection results, or it can be operated as an independent system in a complex environment when the detection efficiency of the acoustic sensor array and other systems decreases, and can detect incoming projectiles within a 360° range. For all gunpowder-launched or gunpowder-propelled projectile threats, including pistols, pistols, rifles, sniper rifles, machine guns, assault rifles, rockets, etc. These projectiles include supersonic and subsonic projectiles, as well as projectiles fired with silencers. The electric field sensor array can detect incoming projectiles in scenes with high background acoustic and optical noise. Summary of the invention

[0003] The present invention provides a passive electric field detection system and method for projectile directional measurement, which solves the problem of reduced projectile detection rate caused by the interference of acoustic and optical background noise on acoustic and infrared sensor arrays in complex environments.

[0004] The technical solution to realize the present invention is: a passive electric field detection system for projectile directional measurement, arranged on the top of a vehicle, including a tetradecahedron connector, a main sensor bracket, a fixing seat and seven electric field sensors, one end of the main sensor bracket is connected to the center of the tetradecahedron connector, and the other end is connected to the fixing seat; the seven electric field sensors are respectively fixed to the tetradecahedron connector through sub-sensor connecting rods, wherein the sub-sensor connecting rods of six electric field sensors are orthogonal to each other, and the sub-sensor connecting rod of the seventh electric field sensor is arranged coaxially with the main sensor bracket.

[0005] The seven electric field sensors have the same structure and are named as the first electric field sensor, the second electric field sensor, the third electric field sensor, the fourth electric field sensor, the fifth electric field sensor, the sixth electric field sensor and the seventh electric field sensor respectively; the connecting rods of the seven sub-sensors have the same length and diameter and are hollow rods.

[0006] A detection method of a passive electric field detection system for projectile directional measurement, the steps are as follows:

[0007] Step 1: Arrange the passive electric field detection system for projectile orientation measurement on the top of the vehicle, with no shielding around the passive electric field detection system.

[0008] Step 2: When a projectile strikes, the electric field sensor induces electric charge in the electrostatic field of the incoming projectile, converts and amplifies the induced charge into a voltage signal, and sends the voltage signal to the signal processing module.

[0009] The sensing electrodes in the electric field sensor induce electric charges in the electrostatic field of the incoming projectile, and the induced charges are converted and amplified into voltage signals by the signal conditioning circuit.

[0010] Step 3: The signal processing module calculates the voltage signal as 1 OY 1 Z 1 The azimuth and elevation of the incoming projectile.

[0011] Compared with the prior art, the present invention has the following significant advantages:

[0012] (1) The present invention uses a tetradecahedron connector as a connecting structure between seven electric field sensors, which can ensure that six of the electric field sensors are arranged in a standard spatial orthogonal manner, which is conducive to measuring the three-dimensional electric field intensity changes in space and realizing the detection of projectiles. By setting six orthogonal electric field sensors and one reference electric field sensor to measure the electric potential signal, the pitch angle and azimuth angle of the target can be solved with a smaller error.

[0013] (2) The electric field sensor design of the present invention adopts active shielding and passive shielding to improve detection sensitivity. The electric field sensor is not interfered by high-frequency acoustic background noise such as explosions, and is not interfered by high-frequency electromagnetic signals. It can be integrated with acoustic sensors to obtain a higher detection rate of incoming projectiles.

[0014] (3) The present invention can be combined with acoustic sensing technology, infrared sensing technology, etc. to improve the detection accuracy of the target. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The figure is a top view of a passive electric field detection system for projectile orientation measurement according to the present invention.

[0016] Figure 2 The figure is a side view of a passive electric field detection system for projectile orientation measurement according to the present invention.

[0017] Figure 3 This is a cross-sectional view of the structure of the electric field sensor.

[0018] Figure 4 The figure is a schematic diagram of the overall structure of a passive electric field detection system for projectile orientation measurement according to the present invention.

[0019] Figure 5 Graphs of the seven electric field sensor output signals. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0022] In addition, in the present invention, the descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0023] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; "connection" can be a mechanical connection or an electrical connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0025] The following will further introduce the specific implementation method, as well as the technical difficulties and inventive points of this invention in combination with this design example.

[0026] Combination Figure 1 to Figure 4 The present invention provides a passive electric field detection system for projectile orientation measurement, which is arranged on the top of a vehicle and includes a tetradecahedron connector 9, a main sensor bracket 10, a fixing seat 30 and seven electric field sensors, wherein one end of the main sensor bracket 10 is connected to the center of the tetradecahedron connector 9, and the other end is connected to the fixing seat 30. The seven electric field sensors are respectively fixed on the tetradecahedron connector 9 through sub-sensor connecting rods 8, wherein the sub-sensor connecting rods 8 of six electric field sensors are orthogonal to each other, and the sub-sensor connecting rod 8 of the seventh electric field sensor is arranged coaxially with the main sensor bracket 10.

[0027] The seven electric field sensors have the same structure and are named first electric field sensor 1, second electric field sensor 2, third electric field sensor 3, fourth electric field sensor 4, fifth electric field sensor 5, sixth electric field sensor 6 and seventh electric field sensor 7. The seven sub-sensor connecting rods 8 have the same length and diameter and are hollow rods.

[0028] The electric field sensor includes a protective shell 14, and a plate 11, a signal conditioning module 15, a sensor power module 16, a three-core aviation plug 19, an electric field sensor signal line 20, an electric field sensor ground line 21, an electric field sensor power line 22, a first circuit bracket 18, and a second circuit bracket 17 arranged in the protective shell 14. The protective shell 14 is cylindrical, with a bottom plate at the bottom end, a center hole is opened in the center of the bottom plate, the three-core aviation plug 19 is fixed in the center hole, and the sub-sensor connecting rod 8 is fixed to the center of the bottom plate of the protective shell 14. The first circuit bracket 18 is fixed on the bottom plate, the sensor power module 16 is arranged on the first circuit bracket 18, the second circuit bracket 17 is fixed on the top surface of the first circuit bracket 18, and the signal conditioning module 15 is arranged on the second circuit bracket 17. The plate 11 is arranged above the second circuit bracket 17, the plate 11 and the signal conditioning module 15 are connected by a radio frequency coaxial line, and the signal conditioning module 15 and the sensor power module 16 are electrically connected. One end of the electric field sensor signal line 20 , the electric field sensor ground line 21 , and the electric field sensor power line 22 are connected to the sensor power module 16 , and the other end is led out of the protective shell 14 through a three-core aviation plug 19 .

[0029] The protective shell 14 is made of metal to shield the interference of the external electric field on the electric field sensor conditioning circuit inside the protective shell 14.

[0030] The electrode plate 11 is constructed by using PCB copper cladding to form the sensing electrode 12 and the guard ring 13 .

[0031] The protective shell 14 is rounded at the mounting position of the electrode plate 11 to reduce the influence of the distortion of the metal protective shell in the electrostatic field on the sensing electrode 12 .

[0032] The fixing base 30 includes a shell, and a first power module 26, a main power module 27, a second power module 28, a signal processing module 23, a main control module 24, a storage module 25 and a wireless transceiver module 29 in the shell; wherein the first power module 26, the main power module 27 and the second power module 28 are connected in sequence. The signal processing module 23, the main control module 24 and the storage module 25 are connected in sequence, the first power module 26 is respectively connected to the signal processing module 23, the main control module 24 and the storage module 25, the wireless transceiver module 29 is respectively connected to the main control module 24 and the second power module 28, and the signal processing module 23 and the main power module 27 are respectively connected to seven electric field sensors.

[0033] The electric field sensor signal line 20, electric field sensor ground line 21, and electric field sensor power line 22 led out from the three-core aviation plug 19 enter the outer shell of the fixed base 30 through the sub-sensor connecting rod 8, the tetradecahedron connector 9, and the main sensor bracket 10, and are connected to the signal processing module 23 and the main power supply module 27.

[0034] The main power module 27 isolates and converts the external DC 24V power supply voltage into a DC 5V voltage, and supplies power to the first power module 26, the second power module 28 and seven electric field sensors; the first power module 26 converts the input DC 5V into DC3.3V and supplies power to the signal processing module 23, the main control module 24, and the storage module 25; the second power module 28 converts the input DC 5V voltage into DC3.3V and supplies power to the wireless transceiver module 29.

[0035] The main power module 27 uses an isolated power supply, a 24V lithium battery or an external power supply.

[0036] A detection method of a passive electric field detection system for projectile directional measurement, the steps are as follows:

[0037] Step 1: Arrange the passive electric field detection system for projectile orientation measurement on the top of the vehicle, with no shielding around the passive electric field detection system.

[0038] Step 2: When a projectile strikes, the electric field sensor induces electric charge in the electrostatic field of the incoming projectile, converts and amplifies the induced charge into a voltage signal, and sends the voltage signal to the signal processing module 23.

[0039] The sensing electrode 12 in the electric field sensor induces electric charge in the electrostatic field of the incoming projectile, and the induced charge is converted and amplified into a voltage signal by the signal conditioning circuit.

[0040] Step 3: The signal processing module 23 calculates the voltage signal as 1 OY 1 Z 1 The azimuth and elevation of the incoming projectile.

[0041] The setting parameters are: the projectile moves in a direction parallel to the top surface of the seventh electric field sensor 7 , moves along the projection direction of the axis of the third electric field sensor 3 and the fourth electric field sensor 4 on the fixing seat 30 , and is 1 m away from the top surface of the seventh electric field sensor 7 .

[0042] for Figure 1 Establish a Cartesian coordinate system XOYZ, assuming that the charge of the projectile is Q, the distance from the origin of the coordinate is R, the angle between the projectile's movement direction and the positive direction of the Z axis is β, and the angle between the projection on the XOY plane and the positive direction of the X axis is α. The first electric field sensor 1 and the second electric field sensor 2 are located on the X axis, the third electric field sensor 3 and the fourth electric field sensor 4 are located on the Y axis, the fifth electric field sensor 5 and the sixth electric field sensor 6 are located on the Z axis, and the electric field sensors on each coordinate axis control the sensor electrode spacing d through the sub-sensor bracket. Under the action of the electrostatic field, the potential on each electric field sensor is E 1 ~E 7 :

[0043]

[0044] In the above formula, ε 0 is the vacuum dielectric constant, which is 8.8542×10 -12 F / m.

[0045] The measurement values ​​of the first electric field sensor 1 to the sixth electric field sensor 6 are used to resolve the angle, the seventh electric field sensor 7 is used as a reference sensor, and the measurement value of the seventh electric field sensor 7 is used to calibrate and evaluate the measurement results.

[0046] Therefore, the two angles α and β related to the direction of projectile motion in the XOYZ coordinate system are solved as:

[0047]

[0048] The projectile motion direction vector (i.e., projectile pointing vector) in the XOYZ coordinate system is converted to the vehicle's reference coordinate system X 1 OY 1 Z 1 , the converted projectile pointing vector p is expressed as follows:

[0049]

[0050] a is the rotation angle along the X axis, b is the rotation angle along the Y axis, c is the rotation angle along the Z axis, and T represents transposition.

[0051] Finally, the vector of the projectile moving relative to the origin of the vehicle coordinate system at a certain point in the projectile's motion path (i.e., the projectile pointing vector) p can be obtained as:

[0052]

[0053] Figure 5 The sampling rate of the measurement results is 50kps, and the interval between each sampling point is 20μs. 1 ~E 7 Substituting the above formula, the projectile pointing vector p at different sampling points n in the path can be calculated: 1 、p 2 ,…,p n :

[0054]

[0055] x n ,y n 、z n Represent the vehicle coordinate system X 1 OY 1 Z 1 The projectile points to the vector pn X 1 Axis component, Y 1 Axis component, Z 1 Axis component.

[0056] The formula can be used to solve the vehicle coordinate system X in real time. 1 OY 1 Z 1 In the middle, the projectile pitch angle j n , azimuth angle k n :

[0057]

[0058] According to Figure 5 The electric field sensor measurement data can be used to calculate when the projectile displacement is 0m, in the vehicle coordinate system X 1 OY 1 Z 1 In the pitch angle j n =87.32°, azimuth k n =-4.36°.

[0059] The angle error between the above calculation result and the actual result is less than 5%, which shows that the method proposed in the present invention is feasible.

Claims

1. A passive electric field detection system for projectile orientation measurement, characterized in that: Arranged on the top of a vehicle, it comprises a tetradecahedron connector (9), a main sensor bracket (10), a fixing seat (30) and seven electric field sensors, wherein one end of the main sensor bracket (10) is connected to the center of the tetradecahedron connector (9), and the other end is connected to the fixing seat (30); the seven electric field sensors are respectively fixed to the tetradecahedron connector (9) via sub-sensor connecting rods (8), wherein the sub-sensor connecting rods (8) of six electric field sensors are orthogonal to each other, and the sub-sensor connecting rod (8) of the seventh electric field sensor is arranged coaxially with the main sensor bracket (10); The seven electric field sensors have the same structure and are named in sequence as a first electric field sensor (1), a second electric field sensor (2), a third electric field sensor (3), a fourth electric field sensor (4), a fifth electric field sensor (5), a sixth electric field sensor (6), and a seventh electric field sensor (7); the seven sub-sensor connecting rods (8) have the same length and diameter and are hollow rods.

2. The passive electric field detection system for projectile orientation measurement according to claim 1, characterized in that: The electric field sensor comprises a protective shell (14), and a plate (11) arranged in the protective shell (14), a signal conditioning module (15), a sensor power module (16), a three-core aviation plug (19), an electric field sensor signal line (20), an electric field sensor ground line (21), an electric field sensor power line (22), a first circuit bracket (18), and a second circuit bracket (17). The protective shell (14) is cylindrical, with a bottom plate at the bottom end, a center hole is opened in the center of the bottom plate, the three-core aviation plug (19) is fixed in the center hole, and the sub-sensor connecting rod (8) is fixedly connected to the center of the bottom plate of the protective shell (14); the first circuit bracket (18) is fixed on the bottom plate, and the first circuit bracket (17) is fixed on the bottom plate. 8), a sensor power module (16) is arranged on the second circuit support (17), a second circuit support (17) is fixed on the top surface of the first circuit support (18), and a signal conditioning module (15) is arranged on the second circuit support (17); the electrode plate (11) is arranged above the second circuit support (17), the electrode plate (11) and the signal conditioning module (15) are connected through a radio frequency coaxial line, and the signal conditioning module (15) and the sensor power module (16) are electrically connected; one end of the electric field sensor signal line (20), the electric field sensor ground line (21), and the electric field sensor power line (22) are connected to the sensor power module (16), and the other end is led out of the protective shell (14) through a three-core aviation plug (19).

3. The passive electric field detection system for projectile orientation measurement according to claim 2, characterized in that: The electrode plate (11) is constructed by using a PCB copper-clad method to construct a sensing electrode (12) and a guard ring (13).

4. The passive electric field detection system for projectile orientation measurement according to claim 3 is characterized in that: The protective shell (14) is rounded at the installation position of the electrode plate (11) to reduce the influence of the distortion of the metal protective shell in the electrostatic field on the induction electrode (12).

5. The passive electric field detection system for projectile orientation measurement according to claim 4, characterized in that: The fixing seat (30) comprises a shell, and a first power module (26), a main power module (27), a second power module (28), a signal processing module (23), a main control module (24), a storage module (25) and a wireless transceiver module (29) inside the shell; wherein the first power module (26), the main power module (27) and the second power module (28) are connected in sequence; the signal processing module (23), the main control module (24) and the storage module (25) are connected in sequence; the first power module (26) is further connected to the signal processing module (23), the main control module (24) and the storage module (25) respectively; the wireless transceiver module (29) is connected to the main control module (24) and the second power module (28) respectively; the signal processing module (23) and the main power module (27) are respectively connected to seven electric field sensors; The main power supply module (27) isolates and converts the external DC 24V power supply voltage into a DC 5V voltage, and supplies energy to the first power supply module (26), the second power supply module (28) and the seven electric field sensors; the first power supply module (26) converts the input DC 5V into DC3.3V and supplies energy to the signal processing module (23), the main control module (24) and the storage module (25); the second power supply module (28) converts the input DC 5V voltage into DC3.3V and supplies energy to the wireless transceiver module (29).

6. The passive electric field detection system for projectile orientation measurement according to claim 5, characterized in that: The electric field sensor signal line (20), the electric field sensor ground line (21), and the electric field sensor power supply line (22) led out from the three-core aviation plug (19) enter the housing of the fixing seat (30) through the sub-sensor connecting rod (8), the tetrahedron connector (9), and the main sensor bracket (10), and are connected to the signal processing module (23) and the main power supply module (27).

7. A detection method based on the passive electric field detection system for projectile orientation measurement according to any one of claims 1 to 6, characterized in that: Here are the steps: Step 1: Arrange the passive electric field detection system for projectile orientation measurement on the top of the vehicle, with no obstructions around the passive electric field detection system; Step 2: When a projectile strikes, the electric field sensor induces electric charge in the electrostatic field of the projectile, converts and amplifies the induced charge into a voltage signal, and sends the voltage signal to the signal processing module (23); The sensing electrode (12) in the electric field sensor induces electric charge in the electrostatic field of the incoming projectile, and the induced charge is converted and amplified into a voltage signal by the signal conditioning circuit; Step 3: The signal processing module (23) calculates the voltage signal into the azimuth and elevation angles of the incoming projectile in the vehicle coordinate system X1OY1Z1.

8. The detection method of the passive electric field detection system for projectile orientation measurement according to claim 7 is characterized in that: In step 3, the signal processing module (23) resolves the voltage signal into the azimuth and elevation angles of the incoming projectile in the vehicle coordinate system X1OY1Z1, as follows: The following parameters are set: the projectile moves in a direction parallel to the top surface of the seventh electric field sensor (7), moves along the projection direction of the axis of the third electric field sensor (3) and the fourth electric field sensor (4) on the fixing seat (30), and is 1 m away from the top surface of the seventh electric field sensor (7); A Cartesian coordinate system XOYZ is established. It is assumed that the charge of the projectile is Q, the distance from the coordinate origin is R, the angle between the projectile movement direction and the positive direction of the Z axis is β, and the angle between the projection on the XOY plane and the positive direction of the X axis is α; the first electric field sensor (1) and the second electric field sensor (2) are located on the X axis, the third electric field sensor (3) and the fourth electric field sensor (4) are located on the Y axis, and the fifth electric field sensor (5) and the sixth electric field sensor (6) are located on the Z axis. The electric field sensors on each coordinate axis control the sensor electrode spacing d through the sub-sensor bracket; under the action of the electrostatic field, the electric potential on each electric field sensor is E1-E7: In the above formula, ε0 is the dielectric constant of vacuum; The measurement values ​​of the first electric field sensor (1) to the sixth electric field sensor (6) are used to calculate the angle, the seventh electric field sensor (7) is used as a reference sensor, and the measurement value of the seventh electric field sensor (7) is used to calibrate and evaluate the measurement results; Therefore, the azimuth angle α and elevation angle β of the projectile in the XOYZ coordinate system are calculated as: The projectile motion direction vector in the XOYZ coordinate system is converted to the vehicle reference coordinate system X1OY1Z1 through the coordinate system, and finally the vector p of the projectile motion relative to the origin of the vehicle coordinate system at a certain point in the projectile motion path is obtained as: Substitute the potentials E1~E7 of each electric field sensor into the above formula to calculate the projectile pointing vectors p1, p2, ..., p at different sampling points n in the path n : Real-time calculation of the projectile's pitch angle j in the vehicle's reference coordinate system X1OY1Z1 n , azimuth angle k n :

9. The detection method of the passive electric field detection system for projectile orientation measurement according to claim 8 is characterized in that: The value of ε0 is 8.8542×10 -12 F / m.

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