A laser anti-UAV test method in foggy environment

Abstract

The present invention relates to the technical field of UAV testing, and specifically to a method for testing laser counter UAVs in a foggy environment, comprising the following steps: step 1, arranging a test platform; step 2, preparing a UAV for testing; step 3, adjusting the test environment; step 4, conducting a laser ablation test against UAVs; step 5, observing and analyzing the morphology of the UAV being ablated; step 6, observing and analyzing the process of laser ablation of UAVs in a foggy environment. The present invention can conduct a test of laser ablation of UAVs in a foggy environment to study the influence mechanism of foggy extreme weather on laser counter UAVs; the present invention conducts indoor tests and is not affected by outdoor weather. Heavy fog can be generated in the test area at any time through an atomizing device, which solves the difficulty of untimely foggy weather, and can control the concentration of water mist to improve the stability and accuracy of the test; the present invention has low test cost and high safety.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicle testing, and in particular to a laser counter-unmanned aerial vehicle testing method in a foggy environment. Background Art

[0002] Drones have been widely used in the civilian field, and their large-scale use has brought about the problem of abuse. For the drone industry, it is not only necessary to solve the design and manufacturing problems of drones, but also the problem of drone countermeasures. The existing mainstream drone countermeasures include soft kill and hard kill: soft kill, by cutting off the radio communication between the drone and the ground, guiding the drone to make an emergency landing or guide it to a designated location. Among them, the laser ablation countermeasure drone in the hard kill has the characteristics of fast attack and low energy consumption. However, based on the optical characteristics of lasers, they are easily affected by weather such as rain and fog during propagation. When a high-energy laser passes through rain and fog, the energy it carries will be gradually absorbed, causing the laser energy to attenuate.

[0003] At present, the impact mechanism of extreme foggy weather on laser countermeasure UAVs has not been clarified. Therefore, it is necessary to design a laser countermeasure UAV test method in a foggy environment. Summary of the invention

[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a laser countermeasure UAV test method in a foggy environment.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: a laser countermeasure drone test method in a foggy environment, comprising the following steps:

[0006] Step 1, arrange the test platform: the test platform at least includes a protective device, an image acquisition device, a laser component, and an atomization device; the test area is provided by the protective device; water mist is generated in the test area by the atomization device; the image during the test is photographed by the image acquisition device; the laser component includes an automatic rotating platform, a high-power laser, and a sight, the high-power laser and the sight are driven by the automatic rotating platform to continuously move in the test area to change the emission direction, the sight emits an aiming laser to detect the drone, and the high-power laser emits a high-power laser to the drone;

[0007] Step 2, prepare the drones for the test: provide several drones, paste strain gauges on the bottom bracket and belly surface of the drones, install acceleration sensors on the upper surface of the drones, paste temperature sensors near the ablation area, and ensure that the strain gauges and the temperature sensors are well attached to the drones;

[0008] Step 3, adjusting the test environment: placing the drone in the test area, turning on the atomization device, filling the test area with water mist, measuring the water mist concentration in real time, and turning off the atomization device when the water mist concentration reaches a preset test standard;

[0009] Step 4, conducting a laser ablation counter-UAV test: turning on the image acquisition device, remotely controlling the UAV to fly in the test area, turning on the automatic rotating platform and the sight, and when the sight detects the UAV, turning on the high-power laser, and the high-power laser emits a high-power laser to the UAV to ablate and destroy the UAV;

[0010] Step 5, observing and analyzing the morphology of the ablated UAV: ​​selecting the structure of the ablated area of ​​the UAV and performing microscopic analysis using a scanning electron microscope;

[0011] Step 6, observe and analyze the process of laser ablation of the UAV in a foggy environment: observe the entire process of the UAV from the beginning of ablation to the falling, and count the time from the beginning of ablation to the non-equilibrium state, and the time from the non-equilibrium state to the beginning of rapid falling. According to the influence mechanism of water mist in the test area on high-power laser, analyze the ablation process in a foggy environment.

[0012] Furthermore, in the step 1, it specifically includes:

[0013] The laser assembly is arranged in the protective device, and the protective device is capable of blocking and absorbing high-power laser;

[0014] Surveillance cameras are arranged at several locations in the test area to record the drone test process from multiple angles;

[0015] Arranging a high-speed camera to record the instantaneous posture of the drone falling;

[0016] An infrared camera is arranged to monitor the temperature changes of the entire field during the ablation process of the UAV.

[0017] Furthermore, in step 2, a camera is installed on the drone to obtain an image of the drone when the candle is burned from a first perspective.

[0018] Furthermore, in step 5, when analyzing the microscopic morphology of the ablated UAV structure, the ablation behavior of the UAV structure by the high-power laser is described by the following formula parameters;

[0019] The dual temperature equation of the UAV shell is described by two coupled differential equations, as follows:

[0020] ;

[0021] ;

[0022] in, is the electron density, is the electronic specific heat, is the system electron temperature, It's time. is the electronic thermal conductivity, is the electron-phonon coupling coefficient, is the system lattice temperature, is a one-dimensional laser heat source. is the lattice density, is the lattice specific heat, is the lattice thermal conductivity.

[0023] Furthermore, in step 6, three time parameters need to be obtained by experiment: , , , satisfying the formula:

[0024] ;

[0025] in, is the total time from the start of high-power laser ablation to the start of the rapid fall of the UAV; The time from when the high-power laser starts ablation to when the UAV starts to experience an unbalanced state of rolling, tilting and spinning; It is the time from when the UAV begins to be in an unbalanced state to when it begins to fall rapidly.

[0026] Furthermore, a comprehensive analysis is performed on the image captured by the image acquisition device and the signal of the acceleration sensor to determine whether the drone begins to fall rapidly.

[0027] Furthermore, in step 6, the influence of the water mist concentration in the test area on the high-power laser specifically includes:

[0028] Water mist will cause high-power laser to scatter. When the photons of high-power laser are directly scattered by particles to the observation point during transmission, primary scattering occurs. When the first particle scatters the photons to the second particle, and the second particle then scatters the scattered light beam of the first particle to the observation point, secondary scattering occurs. In this way, multiple scattering of high-power laser in water mist is defined.

[0029] The Monte Carlo method is used to study the multiple scattering process. Specifically, the photon is given a certain weight and direction to enter the medium and collide with the particles in the medium; the scattering phase function is sampled to obtain the new direction of movement of the photon after the collision. The photon collides with the particle multiple times until the weight value of the photon is lower than the critical value; the spatial coordinates of the photon are , the weight of the photon is ; Assume that the initial coordinates of the photon are (0,0,0), and the initial deflection angle of the photon is , the initial azimuth is , the initial weight of the photon is 1, and the initial transmission direction of the photon is for:

[0030] U 0 = [ u x 0 u y 0 u z 0 ] = [ sin i 0 sin i 0 cos i 0 cos f 0 sin f 0 ] ;

[0031] Where: Indicates the transmission direction is The x-axis coordinate at time; Indicates the transmission direction is The y-axis coordinate at time; Indicates the transmission direction is The z-axis coordinate at time;

[0032] The length of the photon's path can be expressed as:

[0033] ;

[0034] Where: represents a random number uniformly distributed on (0,1); represents the absorption number of the particle; represents the scattering coefficient of the particle;

[0035] The expression of the phase function of photon scattering is:

[0036] ;

[0037] Where: represents the scattering asymmetry factor;

[0038] The phase function of photon scattering is sampled to obtain the scattering angle after each collision :

[0039] i s = arc cos { 1 2 g [ 1 + g 2 − ( 1 − g 2 ) 2 ( 1 − g + 2 g g ) 2 ] } ;

[0040] Azimuth Uniformly distributed in [0,2π], it can be expressed as:

[0041] ;

[0042] Photons pass through Direction of movement after the second collision It can be expressed as:

[0043] ;

[0044] Where: Indicates that the photon is passing through After the collision The coordinates of the axes; Indicates that the photon is passing through After the collision The coordinates of the axes; Indicates that the photon is passing through After the collision The coordinates of the axes;

[0045] The energy of a photon will decrease after a collision, and the corresponding weight of the photon will also decrease. The photon weight after a collision can be expressed as:

[0046] ;

[0047] Where: It means that the photon passes through The weight after the collision; It means that the photon passes through The weight after the collision;

[0048] When the weight of the photon reaches the survival critical value or the photon reaches the receiving surface, stop tracking the photon.

[0049] It can be seen from the above description of the present invention that, compared with the prior art, the laser countermeasure drone test method in a foggy environment of the present invention includes at least one of the following beneficial effects:

[0050] 1. The present invention can conduct laser ablation UAV tests in foggy environments to study the impact mechanism of foggy extreme weather on laser countermeasure UAVs;

[0051] 2. The present invention conducts indoor tests and is not affected by outdoor weather. The atomization device can generate fog in the test area at any time, which solves the problem of untimely foggy weather. The water mist concentration can be controlled to improve the stability and accuracy of the test.

[0052] 3. The test cost of the present invention is low and the safety is high, and the problem of short circuit of the measuring equipment caused by the foggy and humid environment in outdoor tests is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1The present invention is a flowchart of the steps of a laser counter-UAV test method in a foggy environment in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0054] The technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0055] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0056] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] Reference Figure 1 As shown, a preferred embodiment of the present invention is a laser countermeasure UAV test method in a foggy environment, comprising the following steps:

[0058] Step 1, arrange the test platform: the test platform at least includes a protective device, an image acquisition device, a laser component, and an atomization device; the test area is provided by the protective device; water mist is generated in the test area by the atomization device; the image during the test is photographed by the image acquisition device; the laser component includes an automatic rotating platform, a high-power laser, and a sight, the high-power laser and the sight are driven by the automatic rotating platform to continuously move in the test area to change the emission direction, the sight emits an aiming laser to detect the drone, and the high-power laser emits a high-power laser to the drone;

[0059] Step 2, prepare the drones for the test: provide several drones, paste strain gauges on the bottom bracket and belly surface of the drones, install acceleration sensors on the upper surface of the drones, paste temperature sensors near the ablation area, and ensure that the strain gauges and the temperature sensors are well attached to the drones;

[0060] Step 3, adjusting the test environment: placing the drone in the test area, turning on the atomization device, filling the test area with water mist, measuring the water mist concentration in real time, and turning off the atomization device when the water mist concentration reaches a preset test standard;

[0061] Step 4, conducting a laser ablation counter-UAV test: turning on the image acquisition device, remotely controlling the UAV to fly in the test area, turning on the automatic rotating platform and the sight, and when the sight detects the UAV, turning on the high-power laser, and the high-power laser emits a high-power laser to the UAV to ablate and destroy the UAV;

[0062] Step 5, observing and analyzing the morphology of the ablated UAV: ​​selecting the structure of the ablated area of ​​the UAV and performing microscopic analysis using a scanning electron microscope;

[0063] Step 6, observe and analyze the process of laser ablation of the UAV in a foggy environment: observe the entire process of the UAV from the beginning of ablation to the falling, and count the time from the beginning of ablation to the non-equilibrium state, and the time from the non-equilibrium state to the beginning of rapid falling. According to the influence mechanism of water mist in the test area on high-power laser, analyze the ablation process in a foggy environment.

[0064] The present invention can conduct a test of a laser ablation UAV in a foggy environment to study the influence mechanism of extreme foggy weather on the laser counter-UAV; the present invention conducts indoor tests and is not affected by outdoor weather. Heavy fog can be generated in the test area at any time through an atomization device, which solves the difficulty of untimely heavy foggy weather, and can control the water mist concentration to improve the stability and accuracy of the test; the present invention has low test cost and high safety, and avoids the problem that the heavy fog and humid environment in outdoor tests may cause a short circuit to the measuring equipment.

[0065] As a preferred embodiment of the present invention, it may also have the following additional technical features:

[0066] In this embodiment, step 1 specifically includes:

[0067] The laser assembly is arranged in the protective device, and the protective device can block and absorb high-power laser; the protective device should be made of high-temperature resistant material.

[0068] Surveillance cameras are arranged at several locations in the test area to record the drone test process from multiple angles; surveillance cameras can be arranged in all directions around the test area to perform multi-angle shooting.

[0069] A high-speed camera is arranged to record the instantaneous posture of the UAV falling; the process of the UAV being ablated and shot down is relatively short, and a high-speed camera with a frame rate of at least 10,000 frames per second should be used to record the instantaneous posture of the UAV falling.

[0070] An infrared camera is arranged to monitor the temperature changes of the entire field during the ablation process of the UAV.

[0071] In this embodiment, in step 2, a camera is installed on the drone to obtain an image of the drone when the candle is burned from a first perspective.

[0072] In this embodiment, in step 5, when analyzing the microscopic morphology of the ablated UAV structure, the ablation behavior of the UAV structure by the high-power laser is described by the following formula parameters:

[0073] The dual temperature equation of the UAV shell is described by two coupled differential equations, as follows:

[0074] ;

[0075] ;

[0076] in, is the electron density, is the electronic specific heat, is the system electron temperature, It's time. is the electronic thermal conductivity, is the electron-phonon coupling coefficient, is the system lattice temperature, is a one-dimensional laser heat source. is the lattice density, is the lattice specific heat, is the lattice thermal conductivity.

[0077] In this embodiment, in step 6, three time parameters need to be obtained by experiment: , , , satisfying the formula:

[0078] ;

[0079] in, is the total time from the start of high-power laser ablation to the start of the rapid fall of the UAV; The time from when the high-power laser starts ablation to when the UAV starts to experience an unbalanced state of rolling, tilting and spinning; It is the time from when the UAV begins to be in an unbalanced state to when it begins to fall rapidly.

[0080] In this embodiment, a comprehensive analysis is performed on the image captured by the image acquisition device and the signal of the acceleration sensor to determine whether the drone begins to fall rapidly.

[0081] In this embodiment, in step 6, the influence of the water mist concentration in the test area on the high-power laser specifically includes:

[0082] Water mist will cause high-power laser to scatter. When the photons of high-power laser are directly scattered by particles to the observation point during transmission, primary scattering occurs. When the first particle scatters the photons to the second particle, and the second particle then scatters the scattered light beam of the first particle to the observation point, secondary scattering occurs. In this way, multiple scattering of high-power laser in water mist is defined.

[0083] The Monte Carlo method is used to study the multiple scattering process. Specifically, the photon is given a certain weight and direction to enter the medium and collide with the particles in the medium; the scattering phase function is sampled to obtain the new direction of movement of the photon after the collision. The photon collides with the particle multiple times until the weight value of the photon is lower than the critical value; the spatial coordinates of the photon are , the weight of the photon is ; Assume that the initial coordinates of the photon are (0,0,0), and the initial deflection angle of the photon is , the initial azimuth is , the initial weight of the photon is 1, and the initial transmission direction of the photon is for:

[0084] U 0 = [ u x 0 u y 0 u z 0 ] = [ sin i 0 sin i 0 cos i 0 cos f 0 sin f 0 ] ;

[0085] Where: Indicates the transmission direction is The x-axis coordinate at time; Indicates the transmission direction is The y-axis coordinate at time; Indicates the transmission direction is The z-axis coordinate at time;

[0086] The length of the photon's path can be expressed as:

[0087] ;

[0088] Where: represents a random number uniformly distributed on (0,1); represents the absorption number of the particle; represents the scattering coefficient of the particle;

[0089] The expression of the phase function of photon scattering is:

[0090] ;

[0091] Where: represents the scattering asymmetry factor;

[0092] The phase function of photon scattering is sampled to obtain the scattering angle after each collision :

[0093] i s = arc cos { 1 2 g [ 1 + g 2 − ( 1 − g 2 ) 2 ( 1 − g + 2 g g ) 2 ] } ;

[0094] Azimuth Uniformly distributed in [0,2π], it can be expressed as:

[0095] ;

[0096] Photons pass through Direction of movement after the second collision It can be expressed as:

[0097] ;

[0098] Where: Indicates that the photon is passing through After the collision The coordinates of the axes; Indicates that the photon is passing through After the collision The coordinates of the axes; Indicates that the photon is passing through After the collision The coordinates of the axes;

[0099] The energy of a photon will decrease after a collision, and the corresponding weight of the photon will also decrease. The photon weight after a collision can be expressed as:

[0100] ;

[0101] Where: It means that the photon passes through The weight after the collision; It means that the photon passes through The weight after the collision;

[0102] When the weight of the photon reaches the survival critical value or the photon reaches the receiving surface, stop tracking the photon.

[0103] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and improved concepts of the present invention within the technical scope disclosed by the present invention, and they should be covered by the protection scope of the present invention.

Claims

1. A laser countermeasure drone test method in a foggy environment, characterized in that: The following steps are involved: Step 1, arrange the test platform: the test platform at least includes a protective device, an image acquisition device, a laser component, and an atomization device; the test area is provided by the protective device; water mist is generated in the test area by the atomization device; the image during the test is photographed by the image acquisition device; the laser component includes an automatic rotating platform, a high-power laser, and a sight, the high-power laser and the sight are driven by the automatic rotating platform to continuously move in the test area to change the emission direction, the sight emits an aiming laser to detect the drone, and the high-power laser emits a high-power laser to the drone; Step 2, prepare the drones for the test: provide several drones, paste strain gauges on the bottom bracket and belly surface of the drones, install acceleration sensors on the upper surface of the drones, paste temperature sensors near the ablation area, and ensure that the strain gauges and the temperature sensors are well attached to the drones; Step 3, adjusting the test environment: placing the drone in the test area, turning on the atomization device, filling the test area with water mist, measuring the water mist concentration in real time, and turning off the atomization device when the water mist concentration reaches a preset test standard; Step 4, conducting a laser ablation counter-UAV test: turning on the image acquisition device, remotely controlling the UAV to fly in the test area, turning on the automatic rotating platform and the sight, and when the sight detects the UAV, turning on the high-power laser, and the high-power laser emits a high-power laser to the UAV to ablate and destroy the UAV; Step 5, observing and analyzing the morphology of the ablated UAV: ​​selecting the structure of the ablated area of ​​the UAV and performing microscopic analysis using a scanning electron microscope; Step 6, observe and analyze the process of laser ablation of the UAV in a foggy environment: observe the entire process of the UAV from the beginning of ablation to the falling, and count the time from the beginning of ablation to the non-equilibrium state, and the time from the non-equilibrium state to the beginning of rapid falling, and analyze the ablation process in a foggy environment according to the influence mechanism of water mist in the test area on high-power laser; In step 6, the influence of the water mist concentration in the test area on the high-power laser specifically includes: Water mist will cause high-power laser to scatter. When the photons of high-power laser are directly scattered by particles to the observation point during transmission, primary scattering occurs. When the first particle scatters the photons to the second particle, and the second particle then scatters the scattered light beam of the first particle to the observation point, secondary scattering occurs. In this way, multiple scattering of high-power laser in water mist is defined. The Monte Carlo method is used to study the multiple scattering process. Specifically, the photon is given a certain weight and direction to enter the medium and collide with the particles in the medium; the scattering phase function is sampled to obtain the new movement direction of the photon after the collision. The photon collides with the particle multiple times until the weight value of the photon is lower than the critical value; the spatial coordinates of the photon are , the weight of the photon is ; Assume that the initial coordinates of the photon are (0,0,0), and the initial deflection angle of the photon is , the initial azimuth is , the initial weight of the photon is 1, and the initial transmission direction of the photon is for: ； Where: Indicates the transmission direction is The x-axis coordinate at time; Indicates the transmission direction is The y-axis coordinate at time; Indicates the transmission direction is The z-axis coordinate at time; The length of the photon's path can be expressed as: ； Where: represents a random number uniformly distributed on (0,1); represents the absorption number of the particle; represents the scattering coefficient of the particle; The expression of the phase function of photon scattering is: ； Where: represents the scattering asymmetry factor; The phase function of photon scattering is sampled to obtain the scattering angle after each collision : ； Azimuth exist[ ] is uniformly distributed, which can be expressed as: ； Photons pass through Direction of movement after the collision It can be expressed as: ； Where: Indicates that the photon is passing through After the collision The coordinates of the axes; Indicates that the photon is passing through After the collision The coordinates of the axes; Indicates that the photon is passing through After the collision The coordinates of the axes; The energy of a photon will decrease after a collision, and the corresponding weight of the photon will also decrease. The photon weight after a collision can be expressed as: ； Where: It means that the photon passes through The weight after the collision; It means that the photon passes through The weight after the collision; When the weight of the photon reaches the survival critical value or the photon reaches the receiving surface, stop tracking the photon.

2. The laser countermeasure drone test method in a foggy environment according to claim 1 is characterized in that: In the step 1, it specifically includes: The laser assembly is arranged in the protective device, and the protective device is capable of blocking and absorbing high-power lasers; Surveillance cameras are arranged at several locations in the test area to record the drone test process from multiple angles; Arrange a high-speed camera to record the instantaneous posture of the drone falling; An infrared camera is arranged to monitor the temperature changes of the entire field during the ablation process of the UAV.

3. The laser countermeasure drone test method in a foggy environment according to claim 1 is characterized in that: In step 2, a camera is installed on the drone to obtain an image of the drone when the candle is burned from a first perspective.

4. The laser countermeasure drone test method in a foggy environment according to claim 1 is characterized in that: In step 5, when analyzing the microscopic morphology of the ablated UAV structure, the ablation behavior of the UAV structure by the high-power laser is described by the following formula parameters; The dual temperature equation of the UAV shell is described by two coupled differential equations, as follows: ； ； in, is the electron density, is the electronic specific heat, is the system electron temperature, It's time. is the electronic thermal conductivity, is the electron-phonon coupling coefficient, is the system lattice temperature, is a one-dimensional laser heat source. is the lattice density, is the lattice specific heat, is the lattice thermal conductivity.

5. The laser countermeasure drone test method in a foggy environment according to claim 1 is characterized in that: In step 6, three time parameters need to be obtained by experiment: , , , satisfying the formula: ； in, is the total time from the start of high-power laser ablation to the start of the rapid fall of the UAV; The time from when the high-power laser starts ablation to when the UAV starts to experience an unbalanced state of rolling, tilting and spinning; It is the time from when the UAV begins to be in an unbalanced state to when it begins to fall rapidly.

6. The laser countermeasure drone test method in a foggy environment according to claim 5 is characterized in that: By comprehensively analyzing the image captured by the image acquisition device and the signal of the acceleration sensor, it is determined whether the drone begins to fall rapidly.

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