Low-level direct drive test system and test method

Abstract

The invention relates to a low-level direct drive test system and test method. The system comprises a signal processing device, a signal generation device, a power amplifier protection device and a signal acquisition device. The signal processing device is connected with the signal generation device and the power amplifier protection device, the output end of a power amplifier in the signal generation device is connected with the power amplifier protection device, the power amplifier protection device is connected with the test end of the aircraft to be tested, and the signal acquisition device is arranged on the aircraft to be tested and connected with the signal processing device; the signal processing equipment is used for controlling the signal generation device to output a test signal, and processing and analyzing the state data of the to-be-tested aircraft acquired by the signal acquisition device to obtain a test result; and the power amplifier protection device is used for monitoring a signal at the output end of the power amplifier and protecting the power amplifier. The power amplifier is protected, so that the power amplifier outputs a stable test signal, and the stability of a test result is improved.

Description

Technical Field

[0001] The present application relates to the technical field of electromagnetic environment effects, and in particular to a low-level direct drive test system and test method. Background Art

[0002] High-intensity radiated field (HIRF) refers to the electromagnetic environment formed by the external radiation of high-power transmitters such as radar, radio, navigation, and radio and television from the ground, ships, offshore platforms, or aircraft. HIRF energy can enter the aircraft through structures such as windshields, windows, doors, or composite body structures, and interfere with airborne systems by radiation or conduction, causing functional abnormalities such as instability of the aircraft control system, malfunction of the control surfaces, sudden changes in engine speed, interference with radio communications, and incorrect display of navigation parameters such as indicated heading and altitude. Therefore, the HIRF environment is a key factor affecting aircraft flight safety. Aircraft-level HIRF testing is an extremely important test in the compliance verification of HIRF protection clauses. There are mainly two test methods: aircraft-level high-level testing and aircraft-level low-level coupling testing. Due to the limitations of factors such as the complexity and costliness of high-level test equipment, the easy damage to the test object, and the easy interference to surrounding electronic equipment, low-level coupling testing is currently a common method used by domestic and foreign aircraft manufacturers when conducting HIRF tests on aircraft. The purpose of aircraft-level HIRF low-level coupling test is to establish the shielding attenuation curve of the aircraft body and the transfer function curve from the external field to the induced current of the internal interconnection harness. According to the differences in coupling mechanisms in different frequency bands, it is divided into low-level swept field (LLSF) test, low-level swept current (LLSC) test and low-level direct drive (LLDD) test.

[0003] However, the aircraft-grade HIRF low-level direct drive test system in related records has the problem of system instability. Summary of the invention

[0004] Based on this, it is necessary to provide a low-level direct drive test system and test method that can improve the stability of the aircraft-grade HIRF low-level direct drive test system in response to the above-mentioned technical problems.

[0005] In a first aspect, the present application provides a low-level direct drive test system, the low-level direct drive test system comprising: a signal processing device, a signal generating device, a power amplifier protection device and a signal acquisition device;

[0006] The signal processing device is respectively connected to the signal generating device and the power amplifier protection device, the output end of the power amplifier in the signal generating device is connected to the power amplifier protection device, the power amplifier protection device is connected to the test end of the aircraft to be tested, and the signal acquisition device is arranged on the aircraft to be tested and connected to the signal processing device;

[0007] The signal processing device is used to control the signal generating device to output the test signal, and to process and analyze the status data of the aircraft to be tested collected by the signal collecting device to obtain the test result;

[0008] The power amplifier protection device is used to monitor the forward signal and the reverse signal at the output end of the power amplifier and perform protection processing on the power amplifier.

[0009] In one embodiment, the power amplifier protection device includes: a directional coupler, a power meter and an attenuator; the first end of the directional coupler is connected to the signal generating device, the second end of the directional coupler is respectively connected to the first end of the power meter, and is connected to the test end of the aircraft to be tested through the attenuator, and the second end of the power meter is connected to the signal processing equipment.

[0010] In one of the embodiments, the low-level direct drive test system further includes: a matching load device, the matching load device being loaded on two test ends of the aircraft to be tested;

[0011] The matching load device is used to match the impedance between the two test ends of the aircraft to be tested.

[0012] In one embodiment, the matching load device includes a matching load and a current transmission loop, and the matching load is loaded on the aircraft to be tested through the current transmission loop;

[0013] A matching load is used to match the impedance between the two test terminals of the aircraft to be tested;

[0014] The current transmission loop is used to form a nearly coaxial transmission line with the aircraft to be tested and to evenly distribute the current on the surface of the aircraft to be tested.

[0015] In one of the embodiments, the current transmission loop includes multiple return conductor branches and multiple collecting coils, and each collecting coil is correspondingly arranged at the intersection of each return conductor branch; the multiple return conductor branches are evenly distributed on the outer surface of the aircraft to be tested, and should be close to the interior of the aircraft to be tested and the surface area corresponding to the cable; the overlapping impedance between the collecting coil and the return conductor branch is less than a first preset impedance threshold, and the overlapping impedance between each collecting coil is also less than a second preset impedance threshold.

[0016] In one embodiment, the material of the return conductor in the return conductor branch is a soft wide copper strip or a soft wide aluminum strip, and the material of the collecting coil is a hard and easily deformable aluminum strip or copper strip; the matching impedance of the current transmission loop is determined by the diameter of the return conductor and the maximum diameter of the aircraft to be tested.

[0017] In one embodiment, the signal acquisition device includes an injection current acquisition unit, a cable current acquisition unit and a surface current density acquisition unit; the injection current acquisition unit is arranged at the injection end of the current transmission loop, the cable current acquisition unit is arranged at the interconnecting cable between the internal devices of the aircraft to be tested, and the surface current density acquisition unit is arranged on the surface of the aircraft to be tested.

[0018] In a second aspect, the present application also provides a low-level direct drive test method, which is applied to a signal processing device, and the method includes:

[0019] The control signal generating device outputs a test signal;

[0020] Processing and analyzing the status data collected by the signal acquisition device on the aircraft to be tested to obtain the test results;

[0021] The signal acquisition device collects the status data of the aircraft under test and processes and analyzes it to obtain the test results, including:

[0022] Obtaining the injection current, cable current and surface current density at a preset position of the aircraft to be tested from the signal acquisition device, and determining whether the injection current, cable current and surface current density meet preset conditions;

[0023] When the preset conditions are met, the transfer function between the external environment of the aircraft under test and the induced current on the internal interconnection cables of the aircraft under test is determined according to the injected current, cable current and surface current density, and a low-level direct drive test is performed on the aircraft under test according to the transfer function.

[0024] In one embodiment, determining whether the injected current, the cable current, and the surface current density meet preset conditions includes:

[0025] Determine the target cross-sectional perimeter according to the injected current and the surface current density, and determine whether the target cross-sectional perimeter is consistent with the actual cross-sectional perimeter of the aircraft to be tested;

[0026] If the target cross-sectional perimeter is consistent with the actual cross-sectional perimeter of the aircraft to be tested, it is determined that the injected current, the cable current and the surface current density meet the preset conditions;

[0027] If the target cross-sectional perimeter is inconsistent with the actual cross-sectional perimeter of the aircraft to be tested, it is determined whether the injected current, cable current and surface current density meet the preset conditions according to their oscillation conditions.

[0028] In one embodiment, determining whether the injected current, the cable current and the surface current density meet a preset condition according to the oscillation of the injected current, the cable current and the surface current density includes:

[0029] Determine whether the injected current, cable current and surface current density are in an oscillatory state;

[0030] If it is determined to be in an oscillating state, it is determined that the injected current, the cable current and the surface current density meet the preset conditions;

[0031] If it is determined that it is not in an oscillation state, it is determined that the injected current, the cable current and the surface current density do not meet the preset conditions.

[0032] In a third aspect, the present application also provides a low-level direct drive test device, the device comprising:

[0033] A control module, used for controlling the signal generating device to output a test signal;

[0034] The processing module is used to process and analyze the status data on the aircraft to be tested collected by the signal collection device to obtain the test results.

[0035] In a fourth aspect, the present application further provides a computer device, the computer device comprising a memory and a processor, the memory storing a computer program, and the processor implementing the following steps when executing the computer program:

[0036] The control signal generating device outputs a test signal;

[0037] The status data collected by the signal acquisition device on the aircraft to be tested is processed and analyzed to obtain the test results.

[0038] In a fifth aspect, the present application further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented:

[0039] The control signal generating device outputs a test signal;

[0040] The status data collected by the signal acquisition device on the aircraft to be tested is processed and analyzed to obtain the test results.

[0041] In a sixth aspect, the present application further provides a computer program product, the computer program product comprising a computer program, and when the computer program is executed by a processor, the following steps are implemented:

[0042] The control signal generating device outputs a test signal;

[0043] The status data collected by the signal acquisition device on the aircraft to be tested is processed and analyzed to obtain the test results.

[0044] The above-mentioned low-level direct drive test system and test method, the system includes a signal processing device, a signal generating device, a power amplifier protection device and a signal acquisition device; the signal processing device is respectively connected to the signal generating device and the power amplifier protection device, the output end of the power amplifier in the signal generating device is connected to the power amplifier protection device, the power amplifier protection device is connected to the test end of the aircraft to be tested, the signal acquisition device is arranged on the aircraft to be tested and connected to the signal processing device; the signal processing device is used to control the signal generating device to output the test signal, and to process and analyze the status data on the aircraft to be tested collected by the signal acquisition device to obtain the test result; the power amplifier protection device is used to monitor the forward signal and the reverse signal at the output end of the power amplifier, and to protect the power amplifier. The above-mentioned test system can make the power amplifier output a stable test signal by real-time monitoring the signal output by the power amplifier and protecting the power amplifier, thereby improving the stability of subsequent test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A schematic diagram of the structure of a low-level direct drive test system in an embodiment;

[0046] Figure 2 It is a structural schematic diagram of a low-level direct drive test system in another embodiment;

[0047] Figure 3 It is a structural schematic diagram of a low-level direct drive test system in another embodiment;

[0048] Figure 4 It is a schematic diagram of the structure of a cage-type coaxial return network in another embodiment;

[0049] Figure 5 It is a structural schematic diagram of a low-level direct drive test system in another embodiment;

[0050] Figure 6 It is a structural schematic diagram of a low-level direct drive test system in another embodiment;

[0051] Figure 7 A schematic diagram of a flow chart of a low-level direct drive test method in one embodiment;

[0052] Figure 8 is an internal structure diagram of a computer device in one embodiment;

[0053] Description of reference numerals:

[0054] 10. Signal processing equipment; 20. Signal generating device; 30. Power amplifier protection device; 40. Signal acquisition device; 301. Directional coupler; 302. Power meter; 303. Attenuator; 401. Injection current acquisition unit; 402. Cable current acquisition unit; 403. Surface current density acquisition unit; 501. Matching load; 502. Current transmission loop. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0057] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0058] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0059] High-intensity radiated field (HIRF) refers to the electromagnetic environment formed by the external radiation of high-power transmitters such as radar, radio, navigation, and radio and television from the ground, ships, offshore platforms, or aircraft. HIRF energy can enter the aircraft through structures such as windshields, windows, doors, or composite body structures, and interfere with airborne systems by radiation or conduction, causing functional abnormalities such as instability of the aircraft control system, malfunction of the control surfaces, sudden changes in engine speed, interference with radio communications, and incorrect display of navigation parameters such as indicated heading and altitude. Therefore, the HIRF environment is a key factor affecting aircraft flight safety. Aircraft-level HIRF testing is an extremely important test in the compliance verification of HIRF protection clauses. There are mainly two test methods: aircraft-level high-level testing and aircraft-level low-level coupling testing. Due to the limitations of factors such as the complexity and costliness of high-level test equipment, the easy damage to the test object, and the easy interference to surrounding electronic equipment, low-level coupling testing is currently a common method used by domestic and foreign aircraft manufacturers when conducting HIRF tests on aircraft. The purpose of aircraft-level HIRF low-level coupling test is to establish the shielding attenuation curve of the aircraft body and the transfer function curve of the external field to the induced current of the internal interconnection harness. According to the difference in coupling mechanism in different frequency bands, it is divided into low-level swept field (LLSF) test, low-level swept current (LLSC) test and low-level direct drive (LLDD) test. However, the aircraft-level HIRF low-level direct drive test system in related records has the problem of system instability.

[0060] The present application provides a low-level direct drive test system and test method, aiming to solve the above-mentioned technical problems. The following embodiments will specifically illustrate the low-level direct drive test system and test method described in the present application.

[0061] In one embodiment, Figure 1 As shown, a low-level direct drive test system is provided, which includes: a signal processing device 10, a signal generating device 20, a power amplifier protection device 30 and a signal acquisition device 40.

[0062] Among them, the signal processing device 10 is respectively connected to the signal generating device 20 and the power amplifier protection device 30, the output end of the power amplifier in the signal generating device 20 is connected to the power amplifier protection device 30, the power amplifier protection device 30 is connected to the test end of the aircraft to be tested, and the signal acquisition device 40 is arranged on the aircraft to be tested and connected to the signal processing device 10; the signal processing device 10 is used to control the signal generating device 20 to output the test signal, and to process and analyze the status data on the aircraft to be tested collected by the signal acquisition device 40 to obtain the test result; the power amplifier protection device 30 is used to monitor the forward signal and the reverse signal at the output end of the power amplifier, and to protect the power amplifier.

[0063] The signal processing device 10 may include an analysis sub-device and a processing sub-device, wherein the analysis sub-device is connected to the processing sub-device, the analysis sub-device is connected to the signal acquisition device 40, and the processing sub-device is respectively connected to the signal generating device 20 and the power amplifier protection device 30; wherein the analysis sub-device may be a spectrum analyzer for receiving the induction current of the cable inside the aircraft , Current density on the aircraft skin surface , and the total injected current The signal can be replaced by an EMI receiver; the processing sub-device can be but is not limited to various personal computers, laptops, smart phones, tablets, Internet of Things devices and portable wearable devices.

[0064] The above-mentioned signal generating device 20 may include an RF signal generator and a power amplifier, the signal processing device 10 is connected to one end of the RF signal generator, the other end of the RF signal generator is connected to the input end of the power amplifier, and the output end of the power amplifier is connected to the power amplifier protection device 30; wherein the RF signal generator is used to generate a low-level RF signal within the test frequency range; the power amplifier is used to amplify the power of the low-level signal output by the RF signal generator, and its gain flatness is required to be controlled within ±3dB within the test frequency range to ensure the stability of the injected current and avoid misjudgment of other reasons (such as resonance) caused by changes in the test data. The required output power can be estimated using the following formula (1) to ensure that the real cable induced current signal can be distinguished from the environmental background noise:

[0065] (1)

[0066] Among them, P0 (dBW) is the output power of the power amplifier, S0 (dBμV) is the background noise signal of the spectrum analyzer at the corresponding test bandwidth, A0 (dBΩ) is the transfer impedance of the cable current monitoring probe, A1 (dB) is the estimated shielding attenuation of the aircraft in the test frequency range, A2 (dB) is the attenuation coefficient of the attenuator, L (cm) is the maximum cross-sectional circumference of the aircraft, and R0 (Ω) is the resistance value of the matching load, usually 50 ohms. The estimated value of the output power can only be used for the selection of the power amplifier before the test. The output power during the actual test process needs to be adjusted in real time according to the size of the current signal.

[0067] The above test results can be a transfer function between the external environment of the aircraft under test and the induced current on the internal interconnection cable of the aircraft under test, or the induced current value on the internal cable under test at the actual HIRF level of the aircraft under test obtained by the transfer function. The signal or energy transmission between the above devices can be transmitted using a coaxial RF cable. The above aircraft under test can be a missile, an airship, a drone, a flying car or other aircraft.

[0068] The working principle of the low-level direct drive test system described in the embodiment of the present application is: Figure 1When the low-level direct drive test system shown in the figure tests the aircraft under test, the signal processing device 10 sends a test instruction to the signal generating device 20 for controlling the signal generating device 20, and sends a protection instruction to the power amplifier protection device 30 for protecting the power amplifier. After receiving the test instruction, the signal generating device 20 can generate a test signal, and then input the test signal to the aircraft under test through the power amplifier protection device 30; after receiving the test signal, the power amplifier protection device 30 can monitor and protect the working state of the power amplifier in real time; when the test signal is input to the aircraft under test, an electromagnetic environment effect can be formed around the aircraft under test, and the signal acquisition device 40 can collect the state data of the aircraft under test under the electromagnetic environment effect, and transmit the state data to the signal processing device 10. After receiving the state data on the aircraft under test, the signal processing device 10 can process and analyze the state data on the aircraft under test to obtain the test result. Specifically, the processing sub-device in the signal processing device 10 can send control information to the RF signal generator in the signal generating device 20. The RF signal generator can generate a low-level RF signal within the test frequency range, and then the power amplifier amplifies the low-level signal output by the RF signal generator. The RF signal after power amplification is input to the aircraft under test through the power amplifier protection device 30. The power amplifier protection device 30 monitors and protects the working state of the power amplifier in real time. The signal acquisition device 40 collects the status data of the aircraft under test under the effect of the electromagnetic environment, and transmits the status data to the analysis sub-device. After the analysis sub-device performs spectrum analysis on the status data on the aircraft under test, the status data after spectrum analysis can be sent to the processing sub-device for processing to obtain the test result.

[0069] The low-level direct drive test system provided by the embodiment of the present application includes: a signal processing device, a signal generating device, a power amplifier protection device and a signal acquisition device; wherein the signal processing device is respectively connected to the signal generating device and the power amplifier protection device, the output end of the power amplifier in the signal generating device is connected to the power amplifier protection device, the power amplifier protection device is connected to the test end of the aircraft to be tested, the signal acquisition device is arranged on the aircraft to be tested and connected to the signal processing device; the signal processing device is used to control the signal generating device to output a test signal, and to process and analyze the status data on the aircraft to be tested collected by the signal acquisition device to obtain a test result; the power amplifier protection device is used to monitor the forward signal and the reverse signal at the output end of the power amplifier, and to protect the power amplifier. The above-mentioned test system can make the power amplifier output a stable test signal by real-time monitoring the signal output by the power amplifier and protecting the power amplifier, thereby improving the stability of subsequent test results.

[0070] In one embodiment, Figure 2 As shown, the power amplifier protection device 30 includes: a directional coupler 301, a power meter 302 and an attenuator 303; the first end of the directional coupler 301 is connected to the signal generating device 20, the second end of the directional coupler 301 is respectively connected to the first end of the power meter 302, and is connected to the test end of the aircraft to be tested through the attenuator 303, and the second end of the power meter 302 is connected to the signal processing device 10.

[0071] The directional coupler 301 is used to distribute the power of the test signal in a certain ratio to obtain a first signal and a second signal, and input the first signal to the power meter 302, and input the second signal to the aircraft under test through the attenuator 303. The power tolerance of the directional coupler 301 should not be less than the maximum output power of the power amplifier. The directional coupler 301 can be set independently of the power amplifier, or it can be embedded in the power amplifier.

[0072] The power meter 302 is used to monitor the test signal in real time according to the first signal, so that the power amplifier can quantitatively control the injected energy.

[0073] Attenuator 303 is used to absorb the reverse power reflected by the aircraft to be tested to prevent the reverse power from returning to the power amplifier and burning the power amplifier. Attenuator 303 is used to isolate the "power amplifier" and the rear-end "coaxial return network composed of the aircraft and the return conductor". Since the characteristic impedance of the coaxial return network in the test frequency range is difficult to match the output impedance of the power amplifier, the attenuator 303 is set here to effectively protect the power amplifier from the impact of the reflected energy. Attenuator 303 should select a bidirectional fixed attenuator 303, and its power tolerance should not be less than the maximum output power of the power amplifier. The attenuation value should be selected as a suitable value. If the attenuation value is too large, the injection current is reduced. If the attenuation value is too small, the power amplifier may still be burned when the reverse power is large. Usually, a 6dB attenuation value is selected. If it is under the condition of full reflection, in the power amplifier, the reflected power is 25% of the forward power. It should be noted that the coaxial RF cable connected to the output end of the attenuator 303 has its core wire overlapped to the injection point on the surface of the aircraft fuselage, and its shielding layer overlapped to the return conductor.

[0074] In one embodiment, Figure 3 As shown, the above-mentioned low-level direct drive test system also includes: a matching load device 50, which is loaded on two test ends of the aircraft to be tested; the matching load device 50 is used to match the impedance between the two test ends of the aircraft to be tested.

[0075] Among them, the matching load device 50 includes a matching load 501 and a current transmission loop 502. The matching load 501 is loaded on the aircraft under test through the current transmission loop 502; the matching load 501 is used to match the impedance between the two test ends of the aircraft under test; the current transmission loop 502 is used to form an approximately coaxial transmission line with the aircraft under test and to evenly distribute the current on the surface of the aircraft under test.

[0076] The matching load 501 is used to match the output impedance of the power amplifier or attenuator 303. A 50Ω non-inductive resistor is usually selected, and its power tolerance should not be less than the maximum output power of the power amplifier plus the attenuator 303. If the output power of the power amplifier is too high, the matching load 501 can also be replaced by a combination of a RF attenuator 303 and a low-power level non-inductive resistor in series.

[0077] The above-mentioned current transmission loop 502 is used to form a transmission network with "transmission line" characteristics with the aircraft, and its forms include two types: cage coaxial return network and ground plane. Among them, the characteristic impedance of the transmission network should match the output impedance of the power amplifier, but due to the complex surface structure of the aircraft to be tested, it is difficult to obtain a stable characteristic impedance within the test frequency range, and at higher frequencies, the characteristic impedance of the transmission network will increase sharply due to the resonance of the fuselage. Therefore, the current transmission loop 502 is set in the form of a cage coaxial return network. The cage coaxial return network can make the current distribution on the surface of the aircraft more uniform, and the test results of this form are more accurate.

[0078] like Figure 4 As shown, the current transmission loop 502 adopts a cage coaxial return network, including multiple return conductor branches and multiple collection coils, each collection coil is correspondingly arranged at the junction of each return conductor branch; multiple return conductor branches are evenly distributed on the outer surface of the aircraft to be tested, and should be close to the surface area corresponding to the interior of the aircraft to be tested and the cable; the overlap impedance between the collection coil and the return conductor branch is less than the first preset impedance threshold, and the overlap impedance between each collection coil is also less than the second preset impedance threshold. The material of the return conductor in the return conductor branch is a soft wide copper strip or a soft wide aluminum strip, and the material of the collection coil is a hard and easily deformable aluminum strip or copper strip; the impedance of the current transmission loop 502 is determined by the diameter of the return conductor and the maximum diameter of the aircraft to be tested.

[0079] The setting of cage coaxial return network should refer to the following principles:

[0080] a) The characteristic impedance of the approximate cylindrical coaxial transmission network can be estimated by referring to the characteristic impedance of the coaxial cable, which can be specifically expressed by formula (2):

[0081] (2)

[0082] Where D is the return conductor diameter, d is the maximum diameter of the aircraft to be tested (such as an airplane), and εr is the relative dielectric constant of air.

[0083] b) The return conductor needs to be tailored to the characteristics of different aircraft. The branches of the return conductor should be evenly distributed around the outer surface of the aircraft and should be close to the surface area inside the aircraft where the equipment under test and wiring harness are installed;

[0084] c) The distance between each branch of the return conductor and the aircraft fuselage should take into account the height of the aircraft belly from the ground and the differences in the structure of different fuselage areas of the aircraft;

[0085] d) Taking into account the influence of parasitic capacitance, in order to achieve a uniform distribution of current density on the aircraft surface as much as possible, the distance between the branches of the return conductor should be smaller than the distance between the branches of the return conductor and the aircraft fuselage;

[0086] e) Soft wide copper strips or wide aluminum strips are preferred for each branch of the return conductor to facilitate on-site installation;

[0087] f) The setting of the collecting coil is very important. First, it is used to support the copper or aluminum strips of each branch of the return conductor and maintain the stability of the characteristic impedance of the entire coaxial return network. Second, it is used to evenly distribute the conduction current on each branch of the return conductor, thereby controlling the uniform distribution of the current density on the aircraft surface.

[0088] g) The coil can be made of hard, easily deformable aluminum or copper bars, and multiple aluminum or copper bars are overlapped to form a shape that matches the aircraft fuselage structure;

[0089] h) The overlapping impedance between the collecting coil and each branch of the return conductor should not be greater than 10mΩ, and the overlapping impedance between the aluminum or copper bars of the collecting coil should also not be greater than 10mΩ.

[0090] Coaxial RF cable is used to transfer signals or energy between devices related to the test system. There are two points to note: a) The core wire of the coaxial RF cable connected to the output end of attenuator 303 is connected to the injection point on the surface of the aircraft fuselage, and its shielding layer is connected to the return conductor; b) The coaxial RF cable between the injection current monitoring probe, cable current monitoring probe, and surface current density probe connected to the electrical / optical converter should be as short as possible, in principle not exceeding 1m, to prevent the coupling of low-frequency RF signals to the cable and affect the accuracy of the test results.

[0091] In one embodiment, Figure 5As shown, the signal acquisition device 40 comprises an injection current acquisition unit 401, a cable current acquisition unit 402 and a surface current density acquisition unit 403; the injection current acquisition unit 401 is arranged at the injection end of the current transmission loop 502, the cable current acquisition unit 402 is arranged at the interconnection cable between the internal devices of the aircraft to be tested, and the surface current density acquisition unit 403 is arranged at the surface of the aircraft to be tested:

[0092] The injection current acquisition unit 401 is used to monitor the total injection current of the aircraft. In order to ensure the accuracy of the test data within the test frequency range, the probe has a relatively flat transfer impedance curve. and the current density on the aircraft skin surface , for the total injected current Normalization processing can effectively avoid changes in test data caused by changes in injected energy due to changes in power amplifier gain, changes in attenuator 303 coefficient, changes in coaxial return network impedance, and other factors.

[0093] Cable current acquisition unit 402, used to monitor the induced current on the interconnecting cables / cable bundles between the internal equipment of the aircraft In order to ensure the accuracy of the test data within the test frequency range, the probe has a relatively flat transfer impedance curve. Normally, the probe should be located within 5 cm of the device port, corresponding to the test layout requirements for the conducted sensitivity of airborne equipment.

[0094] Surface current density acquisition unit 403, used to monitor the current density on the aircraft surface , within the test frequency range, in order to ensure the accuracy of the test data, the probe has a relatively flat transfer impedance curve. The surface current density probe is generally semi-circular, and the flat plate method is used for calibration. Therefore, during the test, the bottom of the probe should be placed flat on the aircraft surface as much as possible to avoid insufficient shielding or the introduction of air gaps, which will lead to inaccurate test data of the probe. The location of the surface current probe should be selected close to the system under test and the interconnecting cables / cable bundles inside the aircraft.

[0095] It should be noted that the coaxial RF cables connecting the injection current acquisition unit 401, the cable current acquisition unit 402, and the surface current density acquisition unit 403 to the electrical / optical converter should be as short as possible, not exceeding 1 m, to prevent the coupling of low-frequency RF signals to the cables and affect the accuracy of the test results.

[0096] In one embodiment, the above-mentioned low-level direct drive test system also includes: an optical fiber transmission device 60, which is respectively connected to the signal acquisition device 40 and the signal processing device 10, and is used to transmit the status data on the aircraft to be tested collected by the signal acquisition device 40 to the signal processing device 10.

[0097] Specifically, the optical fiber transmission device includes an electrical / optical converter, an optical fiber transmission line, and an optical / electrical converter. The electrical / optical converter is arranged on the side of the aircraft to be tested, and the optical / electrical converter is arranged on the side of the signal processing device 10. The optical fiber transmission line is used to transmit the signal obtained by the probe test to the spectrum analyzer over a long distance. The optical fiber transmission device should have a low and stable loss within the test frequency range, and the transmission distance should be no less than 50m. For ease of use and without introducing power supply noise interference, the electrical / optical converter should have a built-in battery.

[0098] The working principle of the above-mentioned optical fiber transmission device is as follows: the electrical / optical converter on the side of the aircraft to be tested is used to transmit the injection current collected by the injection current collection unit 401, the cable current collected by the cable current collection unit 402 and the surface current density collected by the surface current density collection unit 403 through the optical fiber transmission line to the optical / electrical converter on the side of the signal processing device 10 (such as a spectrum analyzer) to transmit the injection current, cable current and surface current density to the analysis sub-device.

[0099] In one embodiment, Figure 6 As shown, a low-level direct drive test system is also provided, which includes: computer equipment, RF signal generator, power amplifier, directional coupler, power meter, attenuator, current transmission loop, matching load, injection current monitoring probe, cable current monitoring probe, surface current density probe, electric / optical converter, optical fiber transmission line and optical / electrical converter and spectrum analyzer.

[0100] Among them, the current transmission loop can be Figure 6 The current conductor shown can also be Figure 4The cage coaxial return network shown. The signal or energy transfer between the devices can be transmitted by coaxial RF cable. The first end of the computer equipment is respectively connected to the power meter, RF signal generator and power amplifier, the second end of the computer equipment is connected to the spectrum analyzer, and the spectrum analyzer is also connected to the power meter and / or RF signal generator; the first end of the directional coupler is connected to the power amplifier, the second end of the directional coupler is respectively connected to the first end of the power meter, and is connected to the test end of the aircraft under test through the attenuator; the matching load is loaded on the aircraft under test through the current transmission loop; the injection current monitoring probe is set at the injection end of the current transmission loop, the cable current monitoring probe is set at the interconnection cable between the internal devices of the aircraft under test, and the surface current density probe is set on the surface of the aircraft under test. The electric / optical converter is set on the side of the aircraft under test, the optical / electrical converter is set on the side of the signal processing device, and the two ends of the optical fiber transmission line are respectively connected to the electric / optical converter and the optical / electrical converter. The operating frequency range of all the above test equipment should at least cover the frequency range of LLDD test, that is, 10kHz to the first resonant frequency of the aircraft. Under normal circumstances, the actual test frequency range is 10kHz to 30MHz. The computer equipment is installed with LLDD test software, of which the typical features are as follows: a) it can control instruments such as RF signal generator, power amplifier, power meter and spectrum analyzer; b) it can control the point frequency, frequency selection and sweep frequency output of the RF signal generator, which is conducive to real-time analysis of the test results at the test site and elimination of some external interference frequencies and resonant frequencies; c) it can automatically set the gain of the power amplifier according to the signal size received by the spectrum analyzer to increase the dynamic range of signal reception; d) it has an automatic protection function. When the reverse power to forward power ratio of the monitored directional coupler reaches a certain proportion (the proportion depends on the reverse power bearing capacity of the power amplifier), the software controls the signal generator and the power amplifier output to shut down to prevent the output load from mismatching and the reflected power from being too large, which may burn out the power amplifier, thereby realizing the function of protecting the test system; e) it has certain data processing functions, which can receive the induction current of the aircraft internal cable received from the spectrum analyzer and the current density on the aircraft skin surface , for the total injected current Perform normalization.

[0101] In one embodiment, a low level direct drive test method is also provided, such as Figure 7 As shown, the method includes:

[0102] S701, control the signal generating device to output a test signal.

[0103] S702, processing and analyzing the status data of the aircraft to be tested collected by the signal collection device to obtain a test result.

[0104] Specifically, the status data of the aircraft under test collected by the signal acquisition device are processed and analyzed to obtain the test results, including: obtaining the injection current, cable current and surface current density at a preset position of the aircraft under test from the signal acquisition device, and determining whether the injection current, cable current and surface current density meet the preset conditions; when the preset conditions are met, determining the transfer function between the external environment of the aircraft under test and the induced current on the internal interconnection cable of the aircraft under test according to the injection current, cable current and surface current density, and performing a low-level direct drive test on the aircraft under test according to the transfer function.

[0105] Among them, determining whether the injected current, cable current and surface current density meet the preset conditions includes: determining the target cross-sectional perimeter according to the injected current and the surface current density, and determining whether the target cross-sectional perimeter is consistent with the actual cross-sectional perimeter of the aircraft to be tested; if the target cross-sectional perimeter is consistent with the actual cross-sectional perimeter of the aircraft to be tested, determining that the injected current, cable current and surface current density meet the preset conditions; if the target cross-sectional perimeter is inconsistent with the actual cross-sectional perimeter of the aircraft to be tested, determining whether the injected current, cable current and surface current density meet the preset conditions based on the oscillation of the injected current, cable current and surface current density.

[0106] Among them, according to the oscillation of the injected current, the cable current and the surface current density, determining whether the injected current, the cable current and the surface current density meet the preset conditions includes: determining whether the injected current, the cable current and the surface current density are in an oscillating state; if it is determined to be in an oscillating state, determining that the injected current, the cable current and the surface current density meet the preset conditions; if it is determined not to be in an oscillating state, determining that the injected current, the cable current and the surface current density do not meet the preset conditions. It should be noted that the three parameters of the injected current, the cable current and the surface current density affect each other, so if one of the parameters oscillates, it can be said that the three parameters are in an oscillating state.

[0107] In the embodiment of the present application, the above-mentioned aircraft to be tested is taken as an example of an aircraft, and the basic principle of the aircraft-level HIRF low-level direct drive (LLDD) test is as follows: first, the relationship between the induced current on the interconnection cable inside the fuselage and the current density on the aircraft skin surface is established through testing; secondly, the relationship between the external HIRF environment of the aircraft and the current density on the skin surface is obtained through electromagnetic numerical calculation; and then, the current density on the aircraft skin surface is used as a medium to obtain the transfer function between the external HIRF environment of the aircraft and the induced current on the interconnection cable inside the fuselage.

[0108] There are two basic assumptions in aircraft-grade HIRF low-level direct drive (LLDD) testing. First, the skin current on the outer surface of the aircraft only generates an induced current on the interconnection cable inside the aircraft through magnetic coupling. Second, the induced current of the interconnection cable inside the aircraft is proportional to the skin current on the outer surface. Specifically, it can be expressed by formula (3):

[0109] (3)

[0110] In the formula, and It indicates the induced current on the internal interconnection cables and the current density on the skin surface of the aircraft in flight. and Indicates the induced current on the aircraft's internal interconnect cables and the current density on the aircraft's skin surface under the LLDD test state. The induced current is in amperes and the surface current density is in amperes / meter. , the electric field strength of the aircraft's external HIRF environment , formula (3) can be transformed into formula (4):

[0111] (4)

[0112] Therefore, the transfer function between the HIRF environment outside the aircraft and the induced current on the interconnection cables inside the aircraft is:

[0113] (5)

[0114] The relationship between the external HIRF environment and the skin current density of the aircraft under all illumination angles and polarization conditions can be determined by simulation calculations of the aircraft 3D numerical model. The parameters that need to be collected during the simulation LLDD test are mainly , and .

[0115] The specific low-level direct drive test method is as follows:

[0116] (1) Use the preset algorithm to establish a three-dimensional numerical model of the aircraft under external HIRF environment irradiation, and then) obtain the relationship between the external HIRF environment of the aircraft and the current density on the aircraft skin surface under all irradiation angles and polarization conditions through electromagnetic simulation calculation of the three-dimensional numerical model of the aircraft , and then build a return conductor according to the structural characteristics of the aircraft to form a current transmission network with the aircraft. Figure 6 The connection method shown is used to connect all test equipment, build an aircraft-grade HIRF low-level direct drive test system, and debug the test system to obtain a debugged low-level direct drive test system.

[0117] (2) Conduct preliminary tests on surface current density and induced current at multiple locations on the aircraft surface and on multiple cables / wiring harnesses inside the aircraft. Ensure that all test signals are at least 6 dB above the noise floor within the test frequency range, and clearly define the power amplifier output power P0 for subsequent repeated tests.

[0118] (3) Select the first cable / harness test position inside the aircraft, install the induction current monitoring probe, install the surface current density probe on the corresponding aircraft surface, and install the injection current monitoring probe at the injection port;

[0119] (4) Start the formal test. Within the test frequency range, control the power amplifier to stabilize the output power P0 and collect the cable induced current at the first position. , surface current density and the total injected current ;

[0120] (5) Inducing current in the cable and surface current density Relative to the total injected current Perform normalization processing;

[0121] (6) Judgment Is the value close to the circumference of the aircraft section that is perpendicular to the current direction at the surface current density test location? If the difference is not large, proceed to the next step of the test;

[0122] (7) If some frequency points differ greatly, determine whether it is caused by the resonance of the fuselage. If so, proceed to the next step of testing;

[0123] (8) If the problem is not caused by fuselage resonance, check the test system configuration and test operation, find any problems and make corrections, retest after the corrections are made, and repeat step (6);

[0124] (9) , , Substitute into formula (5) to obtain the transfer function between the HIRF environment outside the aircraft and the induced current on the first tested cable / harness inside the aircraft body;

[0125] (10) Change the test position of the cable / wiring harness under test and repeat steps (3) to (9) until the transfer functions of all cables / wiring harnesses under test are obtained;

[0126] (11) The transfer function is linearly extrapolated according to the actual HIRF level of the aircraft to obtain the induced current value on the internal cable / harness under investigation at the actual HIRF level of the aircraft.

[0127] The method described in the embodiment of the present application is aimed at the evaluation requirements of aircraft HIRF coupling effects in the frequency band of "10kHz to the first resonant frequency of the aircraft", and proposes an aircraft-level HIRF low-level direct drive test system and test method, which is used to obtain the transfer function between the external HIRF environment of the aircraft and the interconnection cable / wiring harness of the internal airborne system of the aircraft. The transfer function introduces the total injection current parameter, normalizes the total injection current by the surface current density and the cable induced current, effectively avoids the inconsistency of the test data caused by factors such as the change of the power amplifier gain, the change of the attenuator coefficient, and the change of the coaxial return network impedance, and improves the robustness of the transfer function. The surface current density is used as the monitoring parameter. Compared with the surface current parameter, it is not necessary to consider the current sweeping width of the fuselage, thereby solving the problem of test error caused by the complex structure of the fuselage; the surface current density, cable induced current and total injected current signals obtained by the test are all transmitted to the spectrum analyzer by the optical fiber transmission system, thereby solving the problem that the low-frequency band radio frequency signal is easily coupled to the coaxial cable, resulting in inaccurate test data; an attenuator is added at the rear end of the power amplifier, thereby effectively solving the problem that the output end of the power amplifier is damaged by excessive reflected energy due to impedance mismatch; a matching load is added between the aircraft and the return conductor, thereby solving the problem of impedance matching with the power amplifier; the several setting principles of the return conductor outside the aircraft can effectively guide the engineering design of the radio frequency transmission network in practice; a directional coupler and a power meter are used to monitor the output power of the power amplifier, and the feedback is fed back to the test software, so that the signal source output and the power amplifier gain can be adjusted in real time through the test software to achieve stable output of the power amplifier.

[0128] The methods described in the above steps are all described in the above embodiments. Please refer to the above description for details and will not be repeated here.

[0129] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0130] Based on the same inventive concept, the embodiment of the present application also provides a low-level direct drive test device for implementing the low-level direct drive test method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more low-level direct drive test device embodiments provided below can refer to the above limitations on the low-level direct drive test method, and will not be repeated here.

[0131] In one embodiment, a low-level direct drive test device is provided, comprising:

[0132] The control module is used to control the signal generating device to output a test signal.

[0133] The processing module is used to process and analyze the status data on the aircraft to be tested collected by the signal collection device to obtain the test results.

[0134] In one embodiment, the above-mentioned processing module is specifically used to obtain the injection current, cable current and surface current density at a preset position of the aircraft under test from the signal acquisition device, and determine whether the injection current, cable current and surface current density meet the preset conditions; when the preset conditions are met, determine the transfer function between the external environment of the aircraft under test and the induced current on the internal interconnection cable of the aircraft under test according to the injection current, cable current and surface current density, and perform a low-level direct drive test on the aircraft under test according to the transfer function.

[0135] In one embodiment, the above-mentioned processing module is specifically used to determine the target cross-sectional circumference based on the injected current and the surface current density, and determine whether the target cross-sectional circumference is consistent with the actual cross-sectional circumference of the aircraft to be tested; if the target cross-sectional circumference is consistent with the actual cross-sectional circumference of the aircraft to be tested, it is determined that the injected current, cable current and surface current density meet the preset conditions; if the target cross-sectional circumference is inconsistent with the actual cross-sectional circumference of the aircraft to be tested, it is determined whether the injected current, cable current and surface current density meet the preset conditions based on the oscillation of the injected current, cable current and surface current density.

[0136] In one embodiment, the above-mentioned processing module is specifically used to determine whether the injected current, cable current and surface current density are in an oscillating state; if it is determined to be in an oscillating state, it is determined that the injected current, cable current and surface current density meet the preset conditions; if it is determined not to be in an oscillating state, it is determined that the injected current, cable current and surface current density do not meet the preset conditions.

[0137] Each module in the above-mentioned low-level direct drive test device can be implemented in whole or in part by software, hardware and their combination. Each of the above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory in the computer device in the form of software, so that the processor can call and execute the corresponding operations of each of the above modules.

[0138] In one embodiment, a computer device is provided. The computer device may be a terminal or a server. The internal structure diagram thereof may be as follows: Figure 8 As shown, the computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and the external device. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be realized through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a low-level direct drive test method is realized. The display unit of the computer device is used to form a visually visible picture, which can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device shell, or an external keyboard, touchpad or mouse.

[0139] Those skilled in the art will understand that Figure 8 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0140] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the following steps are implemented:

[0141] The control signal generating device outputs a test signal;

[0142] Processing and analyzing the status data collected by the signal acquisition device on the aircraft to be tested to obtain the test results;

[0143] The signal acquisition device collects the status data of the aircraft under test and processes and analyzes it to obtain the test results, including:

[0144] Obtaining the injection current, cable current and surface current density at a preset position of the aircraft to be tested from the signal acquisition device, and determining whether the injection current, cable current and surface current density meet preset conditions;

[0145] When the preset conditions are met, the transfer function between the external environment of the aircraft under test and the induced current on the internal interconnection cables of the aircraft under test is determined according to the injected current, cable current and surface current density, and a low-level direct drive test is performed on the aircraft under test according to the transfer function.

[0146] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0147] Determine the target cross-sectional perimeter according to the injected current and the surface current density, and determine whether the target cross-sectional perimeter is consistent with the actual cross-sectional perimeter of the aircraft to be tested;

[0148] If the target cross-sectional perimeter is consistent with the actual cross-sectional perimeter of the aircraft to be tested, it is determined that the injected current, the cable current and the surface current density meet the preset conditions;

[0149] If the target cross-sectional perimeter is inconsistent with the actual cross-sectional perimeter of the aircraft to be tested, it is determined whether the injected current, cable current and surface current density meet the preset conditions according to their oscillation conditions.

[0150] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0151] Determine whether the injected current, cable current and surface current density are in an oscillatory state;

[0152] If it is determined to be in an oscillating state, it is determined that the injected current, the cable current and the surface current density meet the preset conditions;

[0153] If it is determined that it is not in an oscillation state, it is determined that the injected current, the cable current and the surface current density do not meet the preset conditions.

[0154] The above embodiment provides a computer device, whose implementation principle and technical effect are similar to those of the above method embodiment, and will not be repeated here.

[0155] In one embodiment, a computer readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented:

[0156] The control signal generating device outputs a test signal;

[0157] Processing and analyzing the status data collected by the signal acquisition device on the aircraft to be tested to obtain the test results;

[0158] The signal acquisition device collects the status data of the aircraft under test and processes and analyzes it to obtain the test results, including:

[0159] Obtaining the injection current, cable current and surface current density at a preset position of the aircraft to be tested from the signal acquisition device, and determining whether the injection current, cable current and surface current density meet preset conditions;

[0160] When the preset conditions are met, the transfer function between the external environment of the aircraft under test and the induced current on the internal interconnection cables of the aircraft under test is determined according to the injected current, cable current and surface current density, and a low-level direct drive test is performed on the aircraft under test according to the transfer function.

[0161] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0162] Determine the target cross-sectional perimeter according to the injected current and the surface current density, and determine whether the target cross-sectional perimeter is consistent with the actual cross-sectional perimeter of the aircraft to be tested;

[0163] If the target cross-sectional perimeter is consistent with the actual cross-sectional perimeter of the aircraft to be tested, it is determined that the injected current, the cable current and the surface current density meet the preset conditions;

[0164] If the target cross-sectional perimeter is inconsistent with the actual cross-sectional perimeter of the aircraft to be tested, it is determined whether the injected current, cable current and surface current density meet the preset conditions according to their oscillation conditions.

[0165] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0166] Determine whether the injected current, cable current and surface current density are in an oscillatory state;

[0167] If it is determined to be in an oscillating state, it is determined that the injected current, the cable current and the surface current density meet the preset conditions;

[0168] If it is determined that it is not in an oscillation state, it is determined that the injected current, the cable current and the surface current density do not meet the preset conditions.

[0169] The above embodiment provides a computer-readable storage medium, whose implementation principle and technical effect are similar to those of the above method embodiment, and will not be repeated here.

[0170] In one embodiment, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the following steps:

[0171] The control signal generating device outputs a test signal;

[0172] Processing and analyzing the status data collected by the signal acquisition device on the aircraft to be tested to obtain the test results;

[0173] The signal acquisition device collects the status data of the aircraft under test and processes and analyzes it to obtain the test results, including:

[0174] Obtaining the injection current, cable current and surface current density at a preset position of the aircraft to be tested from the signal acquisition device, and determining whether the injection current, cable current and surface current density meet preset conditions;

[0175] When the preset conditions are met, the transfer function between the external environment of the aircraft under test and the induced current on the internal interconnection cables of the aircraft under test is determined according to the injected current, cable current and surface current density, and a low-level direct drive test is performed on the aircraft under test according to the transfer function.

[0176] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0177] Determine the target cross-sectional perimeter according to the injected current and the surface current density, and determine whether the target cross-sectional perimeter is consistent with the actual cross-sectional perimeter of the aircraft to be tested;

[0178] If the target cross-sectional perimeter is consistent with the actual cross-sectional perimeter of the aircraft to be tested, it is determined that the injected current, the cable current and the surface current density meet the preset conditions;

[0179] If the target cross-sectional perimeter is inconsistent with the actual cross-sectional perimeter of the aircraft to be tested, it is determined whether the injected current, cable current and surface current density meet the preset conditions according to their oscillation conditions.

[0180] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0181] Determine whether the injected current, cable current and surface current density are in an oscillatory state;

[0182] If it is determined to be in an oscillating state, it is determined that the injected current, the cable current and the surface current density meet the preset conditions;

[0183] If it is determined that it is not in an oscillation state, it is determined that the injected current, the cable current and the surface current density do not meet the preset conditions.

[0184] The above embodiment provides a computer program product, whose implementation principle and technical effect are similar to those of the above method embodiment, and will not be repeated here.

[0185] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0186] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0187] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A low-level direct drive test system, characterized in that: The low-level direct drive test system comprises: a signal processing device, a signal generating device, a power amplifier protection device and a signal acquisition device; The signal processing device is respectively connected to the signal generating device and the power amplifier protection device, the output end of the power amplifier in the signal generating device is connected to the power amplifier protection device, the power amplifier protection device is connected to the test end of the aircraft to be tested, and the signal acquisition device is arranged on the aircraft to be tested and connected to the signal processing device; The signal processing device is used to control the signal generating device to output a test signal, and to process and analyze the status data on the aircraft to be tested collected by the signal collecting device to obtain a test result; The power amplifier protection device is used to monitor the forward signal and the reverse signal at the output end of the power amplifier and perform protection processing on the power amplifier.

2. The system according to claim 1, characterized in that The power amplifier protection device includes: a directional coupler, a power meter and an attenuator; the first end of the directional coupler is connected to the signal generating device, the second end of the directional coupler is respectively connected to the first end of the power meter, and is connected to the test end of the aircraft to be tested through the attenuator, and the second end of the power meter is connected to the signal processing equipment.

3. The system according to claim 1 or 2, characterized in that: The low-level direct drive test system further comprises: a matching load device, the matching load device being loaded on two test ends of the aircraft to be tested; The matching load device is used to match the impedance between the two test ends of the aircraft to be tested.

4. The system according to claim 3, characterized in that The matching load device comprises a matching load and a current transmission loop, and the matching load is loaded on the aircraft to be tested through the current transmission loop; The matching load is used to match the impedance between the two test ends of the aircraft to be tested; The current transmission loop is used to form a nearly coaxial transmission line with the aircraft to be tested, and to evenly distribute the current on the surface of the aircraft to be tested.

5. The system according to claim 4, characterized in that The current transmission loop includes multiple return conductor branches and multiple collecting coils, and each of the collecting coils is correspondingly arranged at the intersection of each return conductor branch; the multiple return conductor branches are evenly distributed on the outer surface of the aircraft to be tested, and should be close to the interior of the aircraft to be tested and the surface area corresponding to the cable; the overlapping impedance between the collecting coil and the return conductor branch is less than a first preset impedance threshold, and the overlapping impedance between each of the collecting coils is also less than a second preset impedance threshold.

6. The system according to claim 5, characterized in that The material of the return conductor in the return conductor branch is a soft wide copper strip or a soft wide aluminum strip, and the material of the collecting coil is a hard and easily deformable aluminum strip or copper strip; the matching impedance of the current transmission loop is determined by the diameter of the return conductor and the maximum diameter of the aircraft to be tested.

7. The system according to claim 4, characterized in that The signal acquisition device includes an injection current acquisition unit, a cable current acquisition unit and a surface current density acquisition unit; the injection current acquisition unit is arranged at the injection end of the current transmission loop, the cable current acquisition unit is arranged at the interconnecting cables between the internal devices of the aircraft to be tested, and the surface current density acquisition unit is arranged at the surface of the aircraft to be tested.

8. A low level direct drive test method, characterized in that: The method is applied to a signal processing device, and the method comprises: The control signal generating device outputs a test signal; Processing and analyzing the status data collected by the signal acquisition device on the aircraft to be tested to obtain the test results; The processing and analysis of the state data collected by the signal collection device on the aircraft to be tested to obtain the test result includes: Acquire the injection current, cable current and surface current density at a preset position of the aircraft to be tested from the signal acquisition device, and determine whether the injection current, the cable current and the surface current density meet preset conditions; When the preset conditions are met, a transfer function between the external environment of the aircraft under test and the induced current on the internal interconnection cable of the aircraft under test is determined according to the injected current, the cable current and the surface current density, and a low-level direct drive test is performed on the aircraft under test according to the transfer function.

9. The method according to claim 8, characterized in that The determining whether the injected current, the cable current, and the surface current density meet preset conditions includes: Determine a target cross-sectional perimeter according to the injected current and the surface current density, and determine whether the target cross-sectional perimeter is consistent with an actual cross-sectional perimeter of the aircraft to be tested; If the target cross-sectional perimeter is consistent with the actual cross-sectional perimeter of the aircraft to be tested, determining that the injected current, the cable current and the surface current density meet a preset condition; If the target cross-sectional circumference is inconsistent with the actual cross-sectional circumference of the aircraft to be tested, it is determined whether the injected current, the cable current and the surface current density meet preset conditions according to the oscillation of the injected current, the cable current and the surface current density.

10. The method according to claim 9, characterized in that The determining, according to the oscillation conditions of the injected current, the cable current, and the surface current density, whether the injected current, the cable current, and the surface current density meet a preset condition comprises: determining whether the injected current, the cable current, and the surface current density are in an oscillating state; If it is determined to be in an oscillating state, determining that the injected current, the cable current and the surface current density meet the preset condition; If it is determined that the device is not in an oscillation state, it is determined that the injected current, the cable current and the surface current density do not satisfy the preset condition.

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