Multi-device cooperative time domain electromagnetic hiding system and method for electromagnetic positioning system

Abstract

The invention discloses a multi-device cooperative time domain electromagnetic hiding system and method for an electromagnetic positioning system, and aims to improve the concealment and survivability of a positioned device cluster in a complex electromagnetic environment. According to the invention, through signal synthesis among multiple devices and dynamic adjustment of phase and time parameters, an electromagnetic waveform with confusion can be generated so as to mislead a positioning result of an electromagnetic positioning system. The positioned equipment cluster comprises a plurality of mobile carriers, signal sources and a control center, the control center is responsible for commanding the mobile carriers, the signal sources carried by the mobile carriers transmit electromagnetic signals, and the positioning precision of electromagnetic positioning equipment can be effectively reduced by changing parameters such as phase, amplitude and forwarding delay of the signals. According to the technical scheme, the electromagnetic hiding effect of the positioned device cluster on the electromagnetic positioning system can be remarkably improved, and the method has important application value in the aspects of device safety and attack defense.

Description

Technical Field

[0001] The present invention relates to electromagnetic concealment technology, and in particular to a multi-device collaborative time-domain electromagnetic concealment system and method for an electromagnetic positioning system, which can be used to improve the concealment and survivability of a cluster of located devices in a complex electromagnetic environment, reduce the probability of being detected and located, and has civil and military significance in the fields of security and anti-attack. Background Art

[0002] Passive radar is a typical electromagnetic positioning system that does not rely on its own emission signals, but instead detects and identifies targets by receiving existing electromagnetic wave signals in the environment. Since the passive radar system does not emit any signals, it has good concealment and cost advantages, and is attractive in many scenarios. Currently, many electromagnetic positioning systems use passive radar as one of their main components. At the same time, with the widespread application of drone technology, the role of drones in some specific scenarios has become increasingly important. However, the electromagnetic radiation signals of drones are easily detected by electromagnetic positioning systems, thereby exposing their location and action intentions. Therefore, certain electronic countermeasures are needed to ensure that drones are not located by electronic positioning systems so that they can work smoothly.

[0003] Existing electronic countermeasures mainly include covering interference, deceptive interference, etc. Covering interference is to use a high-power interference signal to cover or drown out useful signals, thereby preventing the electromagnetic positioning system from detecting target information. Since the electromagnetic positioning system needs to perform target detection under a certain signal-to-noise ratio, when the power of the received interference signal is much greater than the target echo signal, the reduction in the signal-to-noise ratio will cause the system to be difficult to detect the target or make an erroneous judgment, thereby achieving the effect of interference, but this method can only interfere with the detection effect to a certain extent, and it is difficult to effectively conceal the true location of the device, which brings difficulties to the located device to complete the work. Deceptive interference is a technology that uses false or misleading signals to interfere with enemy radar or communication systems. Its purpose is to make the electromagnetic positioning system make erroneous judgments, thereby achieving the effect of concealment, protection or interference. Based on this, the present invention proposes a multi-device collaborative time-domain electromagnetic concealment system and method for an electromagnetic positioning system. Through the dynamic adjustment of parameters such as signal form, phase, and time, the located device cluster can mislead the electromagnetic positioning device, reduce the probability of being detected and located, and has civil and military significance in the fields of security and anti-attack. Summary of the invention

[0004] The present invention proposes a multi-device collaborative time-domain electromagnetic concealment system and method for an electromagnetic positioning system. By adjusting the emission parameters of the signal source and utilizing the signal synthesis and phase disturbance between the located device clusters, the positioning accuracy of the electromagnetic positioning system for the device cluster is reduced. Through this method, the device cluster can achieve positioning interference to the electromagnetic positioning system without affecting the main task, reduce the risk of being detected and attacked, improve the concealment and survivability of the located device cluster in a complex electromagnetic environment, and reduce the probability of being detected and located. It has civil and military significance in the fields of security and anti-attack.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A multi-device cooperative time-domain electromagnetic concealment system for an electromagnetic positioning system includes a control center, at least two signal sources, and a mobile vehicle corresponding to each signal source. The signal source is used to receive instructions transmitted from the corresponding mobile vehicle and transmit the corresponding signal to the outside; the mobile vehicle is used to carry the corresponding signal source and receive instructions from the control center and transmit them to the signal source; the control center is used to send signal control instructions to the mobile vehicle to achieve changes in the parameters of the transmitted signal of the control signal source; the signal source and its corresponding mobile vehicle are connected by wire, and the control center and the mobile vehicle are connected by wireless.

[0007] In particular, the system further includes a microcontroller module located in the mobile vehicle, a controller module located in the control center, a signal generation module located in the signal source, and a radio frequency channel module located between the mobile vehicle and the control center, wherein:

[0008] 1) The microcontroller module is used to process the instructions from the control center and transmit them to the signal generation module of the carried signal source through a wired connection;

[0009] 2) The controller module is used to generate signal control instructions and transmit the instructions to the mobile vehicle through the radio frequency channel;

[0010] 3) The signal generation module is used to receive instructions from the microcontroller module and generate a signal that meets the corresponding parameter requirements according to the instruction content;

[0011] 4) The RF channel module is used to realize the wireless transmission of commands between the control center and the mobile vehicle.

[0012] The working process of the multi-device collaborative time-domain electromagnetic concealment system for the electromagnetic positioning system is as follows: the mobile vehicle moves to a preset position, and when there is a demand for interference with the electromagnetic positioning system, the interference round begins. The control center sends a signal generation instruction through the radio frequency channel module according to the current surrounding electromagnetic environment. After receiving the corresponding instruction, the radio frequency channel module of the mobile vehicle transmits it to the microcontroller module of the mobile vehicle, and transmits it to the signal generation module of the carried signal source through a wired connection to generate a corresponding signal. After confirming the generation of the corresponding signal, the signal generation module returns a confirmation signal to end the current interference round.

[0013] In addition, the present invention emphasizes the use of a time-domain electromagnetic concealment method for an electromagnetic positioning system, which is implemented based on the multi-device collaborative time-domain electromagnetic concealment system that can be used for drone clusters. The method steps include the following:

[0014] 1) Setting at least two signal sources located at different positions;

[0015] 2) enabling each signal source to transmit a specific type of signal, including a continuous sine wave signal and a discrete single-pulse triangular wave signal type, and the phase, amplitude and time parameters of the signal transmitted by each signal source can be dynamically adjusted;

[0016] 3) The signals emitted by each signal source are synthesized and received at the electromagnetic positioning system, forming a false target for the electromagnetic positioning system, so as to achieve distance and angle deception interference to the electromagnetic positioning system;

[0017] 4) setting interference parameters of the signal source transmitting the signal to interfere with the positioning calculation performed by the electromagnetic positioning system based on the time difference of arrival (TDOA) algorithm,

[0018] According to the TDOA algorithm, assuming that the target is located at position P(x, y) and the radar station is located at R 1 and R 2 , the target signal reaches R 1 and R 2 The time is t 1 and t 2 ,(x 1 ,y 1 ) and (x 2 ,y 2 ) are R 1 and r 2 The coordinates of are:

[0019]

[0020] The target position can be obtained by solving the above equations, where △t = t 2 -t 1 , △d=c△t:

[0021]

[0022] Assuming that at this time, after a certain signal source transmits the signal, the signals received by any two devices in the electromagnetic positioning system can be realized respectively as △t 1 and △t 2 According to the calculation formula of TDOA algorithm, the positioning result after interference is as follows, where △t′=t 2 +△t 2 -t 1 -△t 1 , △d′=c△t′:

[0023]

[0024] 5) According to the changes in the electromagnetic environment, real-time adjustment of the signal forwarding delay and phase noise parameters can further reduce the positioning effect of the electromagnetic positioning system.

[0025] According to the signal superposition theory, when the output signals of the two signal sources are set to continuous sinusoidal signals and A is the signal amplitude, are the initial phases of the two signals, and the distances from the signal source to the electromagnetic positioning system are r 1 and r 2 When , the signals from the two signal sources reaching the electromagnetic positioning system are and At this time, the signal received by the electromagnetic positioning system is the superposition of the two signals. in The continuous sine wave signal controlling any signal source is adjusted in a manner of randomly increasing the initial phase within one cycle (2π). Taking the first signal source as an example, at this time To adjust the initial phase value, the positioning accuracy of the positioning system can be reduced by interfering with the electromagnetic signal.

[0026] Similarly, when the output signals of the two signal sources are set to continuous sine wave signals, they are and A is the signal amplitude, are the initial phases of the two signals, and the distances from the signal source to the electromagnetic positioning system are r 1 and r 2 , then the signals from the two signal sources reaching the electromagnetic positioning system are and At this time, the signal received by the electromagnetic positioning system is the superposition of the two signals. in The continuous sine wave signal generated by a certain signal source is controlled in The forwarding delay is adjusted by randomly increasing the range. Taking the first signal source as an example, △t n In order to achieve the forwarding delay, the positioning accuracy of the positioning system can be reduced by interfering with the electromagnetic signal.

[0027] Similarly, when the output signals of the two signal sources are set to discrete single pulse signals Where A is the signal amplitude, T is the pulse width; the distance from the signal source to the electromagnetic positioning system is r 1 for and r 2 , then the signal received by the electromagnetic positioning system is the superposition of the two signals, and the peak values ​​of the received signals are located at and The positions of the two signal sources can be determined at the points where the discrete single-pulse triangle wave signal generated by a certain signal source is controlled to be adjusted within a certain range (generally not exceeding 0.25T) by modifying its duty cycle. Taking the first signal source as an example, at this time T′ is the changed pulse width, which can reduce the positioning accuracy of the positioning system by interfering with the electromagnetic signal.

[0028] Similarly, when the output signals of the two signal sources are set to discrete single pulse signals Where A is the signal amplitude, T is the pulse width; the distance from the signal source to the electromagnetic positioning system is r 1 for and r 2 , then the signal received by the electromagnetic positioning system is the superposition of the two signals, and the peak values ​​of the received signals are located at and The positions of the two signal sources can be determined at The range is adjusted by modifying the forwarding delay. Taking the first signal source as an example, T n In order to change the moment when the positioning system receives the signal, the positioning accuracy of the positioning system can be reduced by interfering with the electromagnetic signal.

[0029] Compared with the traditional method of using clusters of devices to interfere with the electromagnetic positioning system, the main improvements of this method are:

[0030] 1) The present invention has carried out research on the time-domain electromagnetic concealment method for the electromagnetic positioning system from multiple angles such as time, amplitude, phase disturbance, and signal forwarding delay. Compared with the anti-positioning methods such as electromagnetic shielding materials and suppression interference commonly used by current drone clusters, the present invention has a principle innovation, improves the concealment and survivability of the located equipment cluster in a complex electromagnetic environment, reduces the probability of being detected and located, and has civil and military significance in the fields of security and anti-attack;

[0031] 2) The present invention studies the time-domain electromagnetic concealment method for the electromagnetic positioning system from multiple levels such as anti-interception, anti-positioning, and anti-identification, and can produce effective interference positioning effects for various positioning methods such as single-station direction finding and multi-station distributed differential positioning of the electromagnetic positioning system;

[0032] 3) The system of the present invention is an open architecture that can be continuously upgraded and updated, and can evolve. It can adapt to new functions, optimizations and improvements through the upgrade of resource pools and knowledge graphs. Specifically, for the electromagnetic positioning system, the present invention only describes some electromagnetic concealment methods when setting the TDOA algorithm due to the length of the article. Based on the idea of ​​the method of the present invention, other positioning algorithms commonly used in electromagnetic positioning systems can also be set; for the located equipment, the simulation performance of other electromagnetic concealment methods can be tested in the present invention. The overall system can continue to evolve according to the development of technology and changes in demand, allowing the system to grow through continuous iteration and optimization, while allowing new algorithms and models to be added to accommodate more innovations, better adapt to the changing environment and needs, and finally form a complete simulation knowledge base system with strong robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only part of the embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0034] Figure 1 A schematic diagram of a working process of a multi-device collaborative time-domain electromagnetic concealment system for an electromagnetic positioning system according to an embodiment of the present invention;

[0035] Figure 2 It is a schematic diagram of a signal processing flow of a multi-device collaborative time-domain electromagnetic concealment system and method for an electromagnetic positioning system according to an embodiment of the present invention;

[0036] Figure 3 It is a schematic diagram of the modules of a multi-device collaborative time-domain electromagnetic concealment system for an electromagnetic positioning system according to an embodiment of the present invention;

[0037] Figure 4 It is a schematic diagram of a simulated working scenario of a multi-device collaborative time-domain electromagnetic concealment system for an electromagnetic positioning system according to an embodiment of the present invention;

[0038] Figure 5 A comparison of the simulation results of the initial conditions and the random increase in forwarding delay means when the signal source transmits a continuous sinusoidal waveform signal in a multi-device cooperative time-domain electromagnetic concealment system for an electromagnetic positioning system according to an embodiment of the present invention;

[0039] Figure 6 A comparison of simulation results of initial conditions and application of random increase of initial phase when a signal source emits a continuous sinusoidal waveform signal in a multi-device cooperative time-domain electromagnetic concealment system for an electromagnetic positioning system according to an embodiment of the present invention;

[0040] Figure 7 A comparison of simulation results of initial conditions and application of a means of modifying forwarding delay when a signal source transmits a discrete single pulse signal in a multi-device cooperative time-domain electromagnetic concealment system for an electromagnetic positioning system according to an embodiment of the present invention;

[0041] Figure 8 The present invention compares the simulation results of initial conditions and application of modified duty cycle when a signal source transmits a discrete single pulse signal in a multi-device cooperative time-domain electromagnetic concealment system for an electromagnetic positioning system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings.

[0043] Figure 1 The present invention is a schematic diagram of the working process of a multi-device collaborative time-domain electromagnetic concealment system for an electromagnetic positioning system according to an embodiment of the present invention. The mobile vehicle moves to a preset position. When there is a demand for electromagnetic positioning system interference, the interference round begins. The control center sends a signal generation instruction through the radio frequency channel module according to the current surrounding electromagnetic environment. After receiving the corresponding instruction, the radio frequency channel module of the mobile vehicle transmits it to the microcontroller module of the mobile vehicle, and transmits it to the signal generation module of the carried signal source through a wired connection to generate a corresponding signal. After confirming the generation of the corresponding signal, the signal generation module returns a confirmation signal to end the current interference round.

[0044] Figure 2The present invention is a schematic diagram of a simulation signal processing flow of a multi-device collaborative time-domain electromagnetic concealment system and method for an electromagnetic positioning system according to an embodiment of the present invention. During the simulation setting, after completing the setting of the TDOA algorithm for the electromagnetic positioning system, it is also necessary to set the signal system of the signal source. Here, the method involved in the present invention selects two typical signals, namely, a continuous sine wave and a discrete single pulse waveform. When the signal emitted by the signal source is a continuous sine wave, the electromagnetic positioning system indirectly calculates the distance by calculating the phase when the waveform arrives, thereby performing a positioning solution; when the signal emitted by the signal source is a discrete single pulse waveform, the electromagnetic positioning system indirectly calculates the distance by calculating the time difference between the extreme moment and the zero moment when the waveform arrives, thereby performing a positioning solution. By setting different waveforms emitted by the simulated signal source, the signal waveform reaching the electromagnetic positioning system can be calculated. Each electromagnetic positioning system solves the signal received by itself and calculates the distance from the signal source to the electromagnetic positioning system according to the positioning algorithm. Finally, the multi-source positioning system data is fused in combination with the solution results of each electromagnetic positioning system to obtain the positioning result.

[0045] Figure 3 The present invention is a schematic diagram of the modules of a multi-device collaborative time-domain electromagnetic concealment system for an electromagnetic positioning system according to an embodiment of the present invention. The system consists of three parts: a mobile vehicle, a control center, and a signal source. There are at least two signal sources in the located device cluster, and each signal source corresponds to a mobile vehicle. The system module also includes a microcontroller module located in the mobile vehicle, a controller module located in the control center, a signal generation module located in the signal source, and a radio frequency channel module located in the mobile vehicle and the control center, wherein:

[0046] 1) The microcontroller module is used to process the instructions from the control center and transmit them to the signal generation module of the carried signal source through a wired connection;

[0047] 2) The controller module is used to generate signal control instructions and transmit the instructions to the mobile vehicle through the radio frequency channel;

[0048] 3) The signal generation module is used to receive instructions from the microcontroller module and generate a signal that meets the corresponding parameter requirements according to the instruction content;

[0049] 4) The RF channel module is used to realize the wireless transmission of commands between the control center and the mobile vehicle.

[0050] A typical embodiment of the present invention is provided below. A drone is selected as the mobile vehicle in the embodiment. In terms of the selection of working frequencies, the common frequencies commonly used for internal communication in current drone clusters include 2.4GHz, 5.8GHz, etc., but in order to avoid positioning detection and interference of the electromagnetic positioning system as much as possible, 0.9GHz, 1.8GHz and other less crowded working frequencies can be selected as the working frequencies of the embodiments of the present invention to ensure the penetration of electromagnetic signals, the maximum working distance and the data transmission rate. In terms of the selection of the signal source, a software defined radio (Software Defined Radio, SDR) can be used as the output of the analog signal source. The frequency and bandwidth of the USRP (Universal Software Radio Peripheral) device are adjustable, which is suitable for laboratory testing and high-performance requirements. The signal processing process is visualized and designed using open source SDR development platforms such as GNU Radio, and the analog signal frequency, bandwidth and other RF parameters are configured and modulated, and finally the output of the analog signal is realized.

[0051] In terms of communication protocols, the commonly used ZigBee protocol and LoRa protocol are suitable for the low-power, long-endurance networking requirements of drone clusters and low-speed data transmission between nodes, while UAVCAN is a new communication protocol based on the CAN (Controller Area Network) bus with high reliability, low latency and scalability. It is more suitable for drone cluster applications that require rapid response and real-time control and is consistent with the embodiments of the present invention. At the same time, in order to ensure communication performance and efficiency, the network topology must also be selected. The star topology is simple to manage, and all drones communicate with a central node, but at the same time, the central node is prone to become a single point of failure in the system; when the grid topology is adopted, each drone can communicate directly with multiple neighboring nodes, which has high fault tolerance and flexibility, and is more consistent with the embodiments of the present invention.

[0052] Figure 4 The figure is a schematic diagram of a simulated working scenario of a multi-device cooperative time-domain electromagnetic concealment system for an electromagnetic positioning system according to an embodiment of the present invention. The scenario consists of an electromagnetic positioning system and a cluster of located devices. The electromagnetic positioning system includes three sets of electromagnetic positioning devices, which are located at three fixed points, and their positions in the O-xyz coordinate system are r pr1 =[x r1 ,y r1 ,0] T , r pr2 =[x r2 ,y r2 ,0] T and r pr3 =[x r3 ,y r3 ,0] TThe located equipment cluster consists of two sets of located equipment, whose positions in the O-xyz coordinate system are r and d1 =[x d1 ,y d1 ,0] T and r d2 =[x d2 ,y d2 ,0] T In order to simplify the computational complexity and verify the feasibility of the method, all members in the scene are placed on the plane of z = 0, but in order for the electromagnetic positioning system to locate and solve the three-dimensional coordinates of the signal source, three sets of electromagnetic positioning systems are set up.

[0053] Figure 5 The simulation results of the multi-device cooperative time-domain electromagnetic concealment system for the electromagnetic positioning system according to the embodiment of the present invention are compared with the initial conditions when the signal source emits a continuous sinusoidal waveform signal and the simulation results of the random increase in forwarding delay method. Figure 5 (a) is the simulation result of the positioning situation of the embodiment of the present invention under the initial setting conditions. It can be found that circles with the solution results of each electromagnetic positioning system as the radius are drawn, and circles of different colors can intersect at one point and coincide with the set midpoint of the signal source position; Figure 5 (b) is the simulation result of the embodiment of the present invention after applying the method of randomly increasing the forwarding delay. It can be found that the positioning circles of the electromagnetic positioning system cannot intersect at one point, and the area surrounded by the intersection points includes the set midpoint of the signal source position, indicating that the positioning result has a certain deviation.

[0054] Figure 6 This is a comparison of the simulation results of the initial conditions and the application of randomly increased initial phase when the signal source emits a continuous sinusoidal waveform signal for a multi-device collaborative time-domain electromagnetic concealment system for an electromagnetic positioning system according to an embodiment of the present invention. Each ○ represents a set of positioning simulation results. Figure 6 (a) is the simulation result of adding 10 groups of initial phases in the range of -0.003π-0.003π to the upper right signal source. Figure 6 (b) is the simulation result of adding 10 groups of initial phases in the range of -0.01π-0.01π to the upper right signal source. Figure 6 (c) is the simulation result of adding 10 groups of initial phases in the range of -0.07π-0.07π to the upper right signal source. Figure 6 (d) is the simulation result of adding 10 groups of initial phases in the range of -0.25π-0.25π to the upper right signal source. It can be found that as the initial random phase is continuously increased, the interference and deception effect on the positioning result becomes more obvious.

[0055] Figure 7The present invention compares the simulation results of the initial conditions and the means of modifying the forwarding delay when the signal source transmits a discrete single pulse signal in a multi-device cooperative time-domain electromagnetic concealment system for an electromagnetic positioning system according to an embodiment of the present invention. Figure 7 (a) is the simulation result of the signal source waveform and the reception condition of each electromagnetic positioning system under the initial setting conditions of the embodiment of the present invention; Figure 7 (b) is the simulation result of the signal source waveform and the receiving condition of each electromagnetic positioning system under the condition of applying the method of modifying the forwarding delay in the embodiment of the present invention, and there is a certain difference between the two; Figure 7 (c) is the simulation result of the positioning situation of the embodiment of the present invention under the initial setting conditions; Figure 7 (d) is the simulation result of the positioning situation when the forwarding delay modification method is applied in the embodiment of the present invention. It can be found that after adding the forwarding noise, the positioning result for the upper signal source has an obvious deviation.

[0056] Figure 8 The present invention compares the simulation results of initial conditions and application of modified duty cycle when a signal source transmits a discrete single pulse signal in a multi-device cooperative time-domain electromagnetic concealment system for an electromagnetic positioning system according to an embodiment of the present invention. Figure 8 (a) is a simulation setting of different waveforms emitted by a signal source in the direction of each electromagnetic positioning system when a modified duty cycle is applied in an embodiment of the present invention; Figure 8 (b) is a schematic diagram of simulation results of signals received by each electromagnetic positioning system when the duty cycle is modified according to an embodiment of the present invention; Figure 8 (c) is a schematic diagram of the simulation of the positioning results of each electromagnetic positioning system when the duty cycle is modified in the embodiment of the present invention. It can be found that for the signal source with a changed duty cycle, the positioning results of the electromagnetic positioning system have a more obvious offset, which can be considered to have a certain electromagnetic concealment effect. In summary, the embodiment of the present invention can help the located device cluster avoid non-cooperative electromagnetic positioning devices, and is not easily identified and eliminated by the data fusion system of the networked electromagnetic positioning devices, thereby achieving the effects of deception, providing false intelligence, and electromagnetic concealment.

[0057] The method and system of the present invention realize the time-domain electromagnetic concealment for the electromagnetic positioning system from multiple angles such as time, amplitude, phase disturbance, signal forwarding delay, and from multiple levels such as anti-interception, anti-positioning, and anti-identification. Compared with the anti-positioning means such as electromagnetic shielding materials and suppression interference commonly used by current drone clusters, it has a principle innovation, improves the concealment and survivability of the located equipment cluster in a complex electromagnetic environment, reduces the probability of being detected and located, and can produce effective interference positioning effects for various positioning means such as single-station direction finding and multi-station distributed differential positioning of the electromagnetic positioning system; it has civil and military significance in the field of security and anti-attack; at the same time, the system of the present invention is an open architecture that is constantly superimposed, upgraded, and updated, and can evolve, and can adapt to new functions, optimizations, and improvements through the upgrade of resource pools and knowledge graphs. Specifically, for the electromagnetic positioning system, the present invention only describes some electromagnetic concealment methods when setting the TDOA algorithm due to the length of the article. In fact, based on the idea of ​​the present invention, other positioning algorithms commonly used in electromagnetic positioning systems can also be set; for the located equipment, the simulation efficiency of other electromagnetic concealment methods can be tested in the present invention. The overall system can continue to evolve according to the development of technology and changes in demand, allowing the system to grow through continuous iteration and optimization, while allowing the addition of new algorithms and models to accommodate more innovations and better adapt to the ever-changing environment and needs, ultimately forming a complete simulation knowledge base system with strong robustness.

Claims

1. A multi-device collaborative time-domain electromagnetic concealment system for an electromagnetic positioning system, characterized in that: include: A control center, at least two signal sources and a mobile vehicle corresponding to each signal source, wherein the signal source is used to receive instructions transmitted from the corresponding mobile vehicle and transmit corresponding signals to the outside; the mobile vehicle is used to carry the corresponding signal source and receive instructions from the control center and transmit them to the signal source; the control center is used to send signal control instructions to the mobile vehicle to achieve changes in the transmission signal parameters of the control signal source; the signal source and its corresponding mobile vehicle are connected by wire, and the control center and the mobile vehicle are connected by wireless.

2. The multi-device collaborative time-domain electromagnetic concealment system for the electromagnetic positioning system according to claim 1 is characterized in that: The system further includes a microcontroller module located in the mobile vehicle, a controller module located in the control center, a signal generation module located in the signal source, and a radio frequency channel module located between the mobile vehicle and the control center, wherein: 1) The microcontroller module is used to process the instructions from the control center and transmit them to the signal generation module of the carried signal source through a wired connection; 2) The controller module is used to generate signal control instructions and transmit the instructions to the mobile vehicle through the radio frequency channel; 3) The signal generation module is used to receive instructions from the microcontroller module and generate a signal that meets the corresponding parameter requirements according to the instruction content; 4) The RF channel module is used to realize the wireless transmission of commands between the control center and the mobile vehicle.

3. The multi-device collaborative time-domain electromagnetic concealment system for the electromagnetic positioning system according to claim 2 is characterized in that: The mobile vehicle moves to a pre-set position. When there is a need to interfere with the electromagnetic positioning system, the interference round begins. The control center sends a signal generation instruction through the RF channel module according to the current surrounding electromagnetic environment. After receiving the corresponding instruction, the RF channel module of the mobile vehicle transmits it to the microcontroller module of the mobile vehicle, and transmits it to the signal generation module of the carried signal source through a wired connection to generate a corresponding signal. After confirming the generation of the corresponding signal, the signal generation module returns a confirmation signal to end the current interference round.

4. A time domain electromagnetic concealment method for an electromagnetic positioning system, characterized in that: Based on the system implementation according to any one of claims 1 to 3, the method steps include the following: 1) Setting at least two signal sources located at different positions; 2) enabling each signal source to transmit a specific type of signal, including a continuous sine wave signal and a discrete single-pulse triangular wave signal type, and the phase, amplitude and time parameters of the signal transmitted by each signal source can be dynamically adjusted; 3) The signals emitted by each signal source are synthesized and received at the electromagnetic positioning system, forming a false target for the electromagnetic positioning system, so as to achieve distance and angle deception interference to the electromagnetic positioning system; 4) setting interference parameters of the signal transmitted by the signal source to interfere with the positioning calculation performed by the electromagnetic positioning system based on the time difference of arrival (TDOA) algorithm, According to the TDOA algorithm, assuming that the target is located at position P(x, y), the radar stations are located at R1 and R2, the time when the target signal arrives at R1 and R2 is t1 and t2 respectively, (x1, y1) and (x2, y2) are the coordinates of R1 and R2 respectively, then: The target position can be obtained by solving the above equations, where △t = t2-t1, △d = c△t: Assuming that at this time, after a certain signal source transmits the signal, it can respectively achieve △t1 and △t2 effects on the signals received by any two devices in the electromagnetic positioning system. According to the calculation formula of the TDOA algorithm, the positioning result after interference is as follows, where △t ′ =t2+△t2-t1-△t1,△d ′ =c△t ′ : 5) According to the changes in the electromagnetic environment, real-time adjustment of the signal forwarding delay and phase noise parameters can further reduce the positioning effect of the electromagnetic positioning system.

5. The time domain electromagnetic concealment method for the electromagnetic positioning system according to claim 4, characterized in that: When the output signals of the two signal sources are set to continuous sine wave signals and A is the signal amplitude, are the initial phases of the two signals respectively. When the distances from the signal source to the electromagnetic positioning system are r1 and r2 respectively, the signals from the two signal sources to the electromagnetic positioning system are and At this time, the signal received by the electromagnetic positioning system is the superposition of the two signals. in The continuous sine wave signal controlling any signal source is adjusted in a manner of randomly increasing the initial phase within one cycle. Taking the first signal source as an example, at this time To adjust the initial phase value, the positioning accuracy of the positioning system is reduced by interfering with the electromagnetic signal.

6. The time domain electromagnetic concealment method for the electromagnetic positioning system according to claim 4, characterized in that: When the output signals of the two signal sources are set to continuous sine wave signals, they are and A is the signal amplitude, are the initial phases of the two signals respectively, and the distances from the signal source to the electromagnetic positioning system are r1 and r2 respectively. Then the signals from the two signal sources to the electromagnetic positioning system are and At this time, the signal received by the electromagnetic positioning system is the superposition of the two signals. in The continuous sine wave signal generated by a certain signal source is controlled in The forwarding delay is adjusted by randomly increasing the range. Taking the first signal source as an example, △t n In order to achieve the forwarding delay, the positioning accuracy of the positioning system is reduced by interfering with the electromagnetic signal.

7. The time domain electromagnetic concealment method for the electromagnetic positioning system according to claim 4, characterized in that: When the output signals of the two signal sources are set to discrete single pulse signals Where A is the signal amplitude, T is the pulse width; the distances from the signal source to the electromagnetic positioning system are r1 and r2 respectively. At this time, the signal received by the electromagnetic positioning system is the superposition of the two signals. According to the peak values ​​of the received signals, they are located at and The positions of the two signal sources can be determined at the points where the discrete single-pulse triangle wave signal generated by a certain signal source is controlled to be adjusted within a certain range (generally not exceeding 0.25T) by modifying its duty cycle. Taking the first signal source as an example, at this time T ′ The changed pulse width reduces the positioning accuracy of the positioning system by interfering with the electromagnetic signal.

8. The time domain electromagnetic concealment method for the electromagnetic positioning system according to claim 4, characterized in that: When the output signals of the two signal sources are set to discrete single pulse signals Where A is the signal amplitude, T is the pulse width; the distances from the signal source to the electromagnetic positioning system are r1 and r2 respectively. At this time, the signal received by the electromagnetic positioning system is the superposition of the two signals. According to the peak values ​​of the received signals, they are located at and The positions of the two signal sources can be determined at The range is adjusted by modifying the forwarding delay. Taking the first signal source as an example, T n In order to change the moment when the positioning system receives the signal, the positioning accuracy of the positioning system is reduced by interfering with the electromagnetic signal.

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