Electromagnetic effect analysis method and system for unmanned aerial vehicle positioning system based on electromagnetic topological graph

Abstract

The invention belongs to the technical field of electromagnetic effect analysis of unmanned aerial vehicle positioning systems, and particularly relates to an electromagnetic effect analysis method and system for an unmanned aerial vehicle positioning system based on an electromagnetic topological graph. Establishing an electromagnetic topology model and an interference sequence diagram of the unmanned aerial vehicle positioning system; the transient response of any sub-module in the GPS module of the unmanned aerial vehicle to the strong electromagnetic pulse is deduced through the interference sequence diagram; sensitive points are set based on an electromagnetic topology model, a method of combining Solid Work software and ANSYS Maxwell simulation software is utilized to analyze electromagnetic effects after the GPS module sub-module, the GPS module and the preset sensitive points are excited by different interference sources, and electromagnetic distribution characteristics and electromagnetic weak links of the GPS module of the unmanned aerial vehicle are obtained from simulation analysis. According to the invention, the electromagnetic effect analysis of the complex unmanned aerial vehicle positioning system is realized, and the electromagnetic weak link in the unmanned aerial vehicle positioning system is explored.

Description

Technical Field

[0001] The present invention belongs to the technical field of electromagnetic effect analysis of unmanned aerial vehicle positioning systems, and in particular relates to an electromagnetic effect analysis method and system for unmanned aerial vehicle positioning systems based on an electromagnetic topology map. Background Art

[0002] UAV technology is an important development direction in the aviation field, with broad application prospects and potential. UAVs have the advantages of high efficiency, high precision, high flexibility, and low cost. They are capable of performing tasks in various complex environments and have become an important emerging tool in all walks of life. As an integrated complex system, the UAV positioning system contains multiple secondary subsystems and the electromagnetic interference coupling channel is complex, which creates difficulties for exploring the electromagnetic coupling problem of UAVs.

[0003] Electromagnetic topology uses the concept of topology to decompose a complex electronic system, thereby reducing the complexity of the entire system analysis. The basic idea is to decompose the research object space into regions of different sizes, and the regions are connected through the system topology map, so that the entire complex electromagnetic coupling problem can be decomposed into a group of relatively independent small electromagnetic problems to solve. How to use electromagnetic topology to divide the UAV positioning system and the association between modules is the basis for the electromagnetic effect analysis of the UAV positioning system. At present, there are few studies on the electromagnetic topology model of the UAV positioning system at home and abroad. Some scholars have explored the BLT equation and its application in electromagnetic topology analysis; some scholars have proposed the topology map analysis and protection reinforcement method of the HPM effect of the shielding system; the team of the National University of Defense Technology established a multi-layer electromagnetic shielding model based on electromagnetic topology theory, and used linear programming to give an optimization method for the weak path in the model; the University of Information Engineering analyzed the interference coupling mode through the electromagnetic topology model, and analyzed the radiation interference coupling mechanism and action mechanism under different coupling paths. Summary of the invention

[0004] The purpose of the present invention is to solve the problem of high complexity and difficulty in analyzing electromagnetic effects of UAV positioning systems. A method and system for analyzing electromagnetic effects of UAV positioning systems based on electromagnetic topology maps are proposed, which realizes the electromagnetic effect analysis of complex UAV positioning systems and explores the electromagnetic weak links in UAV positioning systems.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for analyzing electromagnetic effects of a UAV positioning system based on an electromagnetic topology map, comprising:

[0007] Using the electromagnetic topology method, the coupling of strong electromagnetic pulses to the UAV positioning system is decomposed into several coupling links, and the electromagnetic topology model and interference sequence diagram of the UAV positioning system are established;

[0008] The transient response of any submodule inside the drone GPS module to a strong electromagnetic pulse is derived through the interference sequence diagram;

[0009] Sensitive points were set based on the electromagnetic topology model, and the physical model of the drone GPS module was constructed using Solid Work software;

[0010] The Step file generated by Solid Work software was imported using ANSYS Maxwell simulation software to analyze the electromagnetic effects of the GPS module sub-modules, GPS module and preset sensitive points after being stimulated by different interference sources. The electromagnetic distribution characteristics and electromagnetic weak links of the UAV GPS module were obtained from the simulation analysis.

[0011] According to the electromagnetic effect analysis method of the UAV positioning system based on the electromagnetic topology map of the present invention, further, the establishment of the electromagnetic topology model of the UAV positioning system includes:

[0012] Based on the internal structure of the UAV GPS module, the electromagnetic topological model of the UAV GPS is established by using the topological graph theory through the graph composed of points and lines and the point and edge relationships represented by the graph; the naming rules in this model are: V represents the sub-area, S represents the shielding shell, V represents the shielding shell, and V represents the shielding shell. i,j The two subscripts represent the area within the i-th shielding shell and the j-th sub-area within the area. k,h:i,j The four subscripts represent V k,h and V i,j The interface between the two sub-areas also represents the shielding shell.

[0013] According to the electromagnetic effect analysis method of the unmanned aerial vehicle positioning system based on the electromagnetic topology diagram of the present invention, further, in the interference sequence diagram, the conduction link is the signal transmission link when the GPS module is working normally, and the electromagnetic interference enters the GPS module through two links. The interference enters the RF front end through the front door coupling and is coupled to the GPS module in a conduction manner; the interference also enters the inside of the GPS module through the back door coupling, and enters the conduction link in a field-line coupling manner through field-to-field coupling between regions.

[0014] According to the electromagnetic effect analysis method of the drone positioning system based on the electromagnetic topology map of the present invention, further, the calculation formula of the transient response of any submodule inside the drone GPS module to the strong electromagnetic pulse is as follows:

[0015]

[0016] Among them, ω p represents the coupling coefficient of different sub-regions in the electromagnetic topology, E i It represents the electric field strength in the area inside the i-th shielding shell, H iIt represents the magnetic field strength in the area inside the i-th shielding shell; represents the transfer function from the hth sub-region within the kth shielding shell to the jth sub-region within the ith shielding shell, r represents the cross-region coupling path, and c represents the cross-conductor coupling path.

[0017] According to the electromagnetic effect analysis method of the drone positioning system based on the electromagnetic topology diagram of the present invention, further, the response expression of the low noise amplifier in the drone GPS module to the strong electromagnetic pulse is as follows:

[0018]

[0019] Represents the electromagnetic pulse response of a strong electromagnetic pulse directly acting on a low noise amplifier through antenna coupling. Represents the coupling path through the filter housing and the filter, Representatives are coupled in through the LNA housing.

[0020] According to the electromagnetic effect analysis method of the UAV positioning system based on the electromagnetic topology map of the present invention, further, the response expression of the timing module in the UAV GPS module to the strong electromagnetic pulse is as follows:

[0021]

[0022] Represents the electromagnetic pulse response of the timing module when a strong electromagnetic pulse is coupled to the antenna. Represents the coupling path through the filter housing and the filter, represents coupling into the LNA housing, Represents the interference effect of strong electromagnetic pulses on the timing module through digital circuits.

[0023] According to the electromagnetic effect analysis method of the UAV positioning system based on the electromagnetic topology map of the present invention, further, the response expression of the intermediate frequency module in the GPS module to the strong electromagnetic pulse is as follows:

[0024]

[0025] Based on the timing module Added The coupling path of the strong electromagnetic pulse is directly coupled from the digital circuit to the intermediate frequency module.

[0026] An electromagnetic effect analysis system for a UAV positioning system based on an electromagnetic topology diagram includes an electromagnetic topology and interference sequence diagram module, a transient response module, a physical model building module and a simulation module, wherein:

[0027] The electromagnetic topology and interference sequence diagram module is used to decompose the coupling of strong electromagnetic pulses to the UAV positioning system into several coupling links using the electromagnetic topology method, and to establish the electromagnetic topology model and interference sequence diagram of the UAV positioning system;

[0028] The transient response module is used to derive the transient response of any submodule inside the drone GPS module to a strong electromagnetic pulse through the interference sequence diagram;

[0029] The physical model building module is used to set sensitive points based on the electromagnetic topology model and build the physical model of the drone GPS module using Solid Work software;

[0030] The simulation module is used to import the Step file generated by the Solid Work software using the ANSYS Maxwell simulation software, analyze the electromagnetic effects of the GPS module sub-modules, GPS module and preset sensitive points after being stimulated by different interference sources, and obtain the electromagnetic distribution characteristics and electromagnetic weak links of the UAV GPS module from the simulation analysis.

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] Based on electromagnetic topology theory, the present invention establishes an electromagnetic topology model and interference sequence diagram of the UAV positioning system, and uses the interference sequence diagram to deduce the transient response of each submodule of the GPS module to a strong electromagnetic pulse, thereby realizing the electromagnetic effect analysis of a complex UAV positioning system. The physical model of the UAV GPS module is constructed using Solid Work software, and the electromagnetic effect simulation is performed after the model is imported using ANSYS Maxwell simulation software. By analyzing the electromagnetic pulse effects of the GPS module submodules, the GPS module, and the pre-set sensitive points, the electromagnetic distribution characteristics and electromagnetic weak links of the UAV GPS module are obtained, providing experimental verification for the proposed electromagnetic topology model of the UAV positioning system.

[0033] The present invention solves the problem of the limitations of analyzing the interference coupling of the entire system by using experiments or numerical methods alone by designing an electromagnetic topological model, thereby realizing the qualitative and quantitative analysis of the UAV positioning system and providing a reliable theoretical basis for the mechanism effect analysis and evaluation of the UAV. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] 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 some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 is a flow chart of an electromagnetic topology strong and weak coupling analysis method according to an embodiment of the present invention;

[0036] Figure 2 is a structural principle diagram of a drone GPS module according to an embodiment of the present invention;

[0037] Figure 3 This is an electromagnetic topology model diagram of the UAV GPS module according to an embodiment of the present invention;

[0038] Figure 4 is a diagram of interference sequence of the GPS module of the drone according to an embodiment of the present invention;

[0039] Figure 5 This is a physical model diagram of the circuit structure in the GPS module of the drone according to an embodiment of the present invention;

[0040] Figure 6 3 are three views of the physical model of the GPS circuit of the embodiment of the present invention. Figure 6 (a) is a side view, Figure 6 (b) is a top view, Figure 6 (c) is a bottom view;

[0041] Figure 7 3 are three views of the overall physical model of the UAV GPS module of the embodiment of the present invention. Figure 7 (a) is a side view, Figure 7 (b) is a top view, Figure 7 (c) is a bottom view;

[0042] Figure 8 It is a model establishment diagram of the unmanned aerial vehicle GPS module in the ANSYS Maxwell simulation software according to an embodiment of the present invention;

[0043] Fig. 9 It is a cloud diagram of the submodules of the GPS module under the excitation of a 100 MHz pulse source according to an embodiment of the present invention;

[0044] Fig.10 This is a cloud diagram of a GPS module under 100 MHz pulse source excitation according to an embodiment of the present invention;

[0045] Fig.11 1 is a curve showing the change of magnetic induction intensity of three types of sensitive points over time under the excitation of a 100 MHz pulse source in an embodiment of the present invention;

[0046] Fig.12 It is a cloud diagram of the submodules of the GPS module under the excitation of a 500 MHz pulse source according to an embodiment of the present invention;

[0047] Fig.13 This is a cloud image of a GPS module under 500MHz pulse source excitation according to an embodiment of the present invention;

[0048] Fig.14 It is a curve of the magnetic induction intensity of three types of sensitive points changing with time under the excitation of a 500 MHz pulse source in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] The electromagnetic effect analysis method of the UAV positioning system based on the electromagnetic topology map of this embodiment includes the following contents:

[0051] Step S101: using an electromagnetic topology method, decomposing the coupling of a strong electromagnetic pulse to a UAV positioning system into several coupling links, and establishing an electromagnetic topology model of the UAV positioning system.

[0052] See also Figure 1 The interference of strong electromagnetic pulses on the UAV positioning system is a one-way relationship in which external interference is coupled into the system, which is a weak coupling interference. The electromagnetic interference coupling generated by each other within the system is a strong coupling interference. According to the interference coupling loop, the system is divided into multiple strong coupling and weak coupling subsystems or modules for analysis, which are synthesized into the electromagnetic pulse response of the system.

[0053] In the drone positioning system, the receiver is more susceptible to strong electromagnetic pulse interference. The interference of strong electromagnetic pulses on the drone positioning system belongs to weak coupling interference that is coupled into the system by external interference. By analyzing the structure of the drone GPS module, such as Figure 2 As shown, the sensitive circuit in the GPS module is the low-noise amplifier in the RF module, which has high sensitivity and large gain and is more susceptible to interference from strong electromagnetic pulses. Damage to the low-noise amplifier will inevitably lead to the collapse of the entire system.

[0054] The research objects of electromagnetic effect are the interference coupling path and the interfered area, which correspond to the binary relationship of electromagnetic topology method respectively. Based on the internal structure of the UAV GPS module, the electromagnetic topology model of UAV GPS is established by using the graph composed of points, lines (edges) and the point and edge relationships represented by the graph using topological graph theory, see Figure 3 The naming rules in this model are: V represents the sub-area divided according to the internal structure of the GPS receiver, S represents the shielding shell, and V i,j The two subscripts represent the area within the i-th shielding shell and the j-th sub-area within the area. k,h:i,j The four subscripts represent Vk,h and V i,j The interface between the two sub-areas also represents the shielding shell.

[0055] Step S102: derive the interference sequence diagram of the GPS module according to the established electromagnetic topology relationship. The electromagnetic pulse response of any submodule of the established drone GPS electromagnetic topology model can be obtained from the interference sequence diagram. Figure 4 .

[0056] The conduction link is the signal transmission link when the GPS module is working normally. Electromagnetic interference enters the GPS module through two links. Interference enters the RF front end through front-door coupling and is coupled to the GPS module in a conduction manner. Interference can also enter the inside of the GPS module through back-door coupling, and enter the conduction link in a field-line coupling manner after field-to-field coupling between regions.

[0057] Step S103: derive the transient response of any submodule inside the GPS module of the drone to the strong electromagnetic pulse through the interference sequence diagram.

[0058] The transfer function represents the efficiency with which the electromagnetic field of one region is coupled to another region through a coupling path, and the efficiency with which the electromagnetic field of one region induces voltage and current on a wire or circuit through field-line coupling.

[0059] Transfer function between external incident field and internal coupled field:

[0060]

[0061] Region V k,h Field-line coupling to the wire L i,j The transfer function on :

[0062]

[0063] The interference generated by electronic devices is coupled to the GPS module through multiple paths. According to the circuit superposition principle, the response of the GPS module to the interference generated by electronic devices can be expressed as:

[0064]

[0065] Among them, ω p represents the coupling coefficient of different sub-regions in the electromagnetic topology, E i It represents the electric field strength in the area inside the i-th shielding shell, H i It represents the magnetic field strength in the area inside the i-th shielding shell; represents the transfer function from the hth sub-region within the kth shielding shell to the jth sub-region within the ith shielding shell, r represents the cross-region coupling path, and c represents the cross-conductor coupling path.

[0066] The following describes the responses of the low noise amplifier, timing module and intermediate frequency module in the drone GPS module to strong electromagnetic pulses.

[0067] (1) Low Noise Amplifier

[0068] The response expression of the low noise amplifier in the drone GPS module to a strong electromagnetic pulse is as follows:

[0069]

[0070] Represents the electromagnetic pulse response of a strong electromagnetic pulse directly acting on a low noise amplifier through antenna coupling. Represents the coupling path through the filter housing and the filter, It represents the three ways of coupling into the low noise amplifier shell and coupling of strong electromagnetic pulses acting on the low noise amplifier together to obtain the response of the low noise amplifier to the strong electromagnetic pulse.

[0071] (2) Timing module

[0072] Through the interference sequence diagram, the timing module and intermediate frequency module in the digital circuit are easily interfered by strong electromagnetic pulses, resulting in clock signal disorder and affecting the normal operation of the GPS module. The response expression of the timing module in the drone GPS module to strong electromagnetic pulses is as follows:

[0073]

[0074] Represents the electromagnetic pulse response of the timing module when a strong electromagnetic pulse is coupled to the antenna. Represents the coupling path through the filter housing and the filter, represents coupling into the LNA housing, It represents the interference of the clock signal of the timing module caused by the strong electromagnetic pulse. The four ways of coupling the strong electromagnetic pulse act on the timing module together to obtain the response of the timing module to the strong electromagnetic pulse.

[0075] (3) Intermediate frequency module

[0076] The response expression of the intermediate frequency module in the GPS module to a strong electromagnetic pulse is as follows:

[0077]

[0078] Based on the timing module Added The coupling path of the strong electromagnetic pulse is directly coupled from the digital circuit to the intermediate frequency module. Therefore, according to the path deduction of the interference sequence diagram, the transient response of any submodule of the GPS module to the strong electromagnetic pulse can be obtained.

[0079] Step S103, in order to verify the validity of the electromagnetic topology model of the drone positioning system. Based on the electromagnetic topology model constructed in step S101, it is easy to set three sensitive points, and use Solid Work software to build a physical model of the drone GPS module; then use ANSYS Maxwell simulation software to import the Step file generated by Solid Work software, analyze the electromagnetic effects of the GPS module submodule, GPS module and the three preset sensitive points after being excited by two different interference sources of 100MHz and 500MHz, and obtain the electromagnetic distribution characteristics and electromagnetic weak links of the drone GPS module from the simulation analysis.

[0080] In order to analyze the electromagnetic effect of the direct irradiation test of the UAV GPS module, the physical model of the UAV GPS module was constructed using Solid Work software. Figure 5 , Figure 6 and Figure 7 Through the physical model established by Solid Work, ANSYS Maxwell simulation software imports the Step file for subsequent electromagnetic effect simulation. The GPS module mainly connects the five main sub-modules of the GPS module in series through six signal lines to realize the functions of the GPS module. For the GPS module simulation model, see Figure 8 . Use ANSYS Maxwell to simulate the B (magnetic induction intensity) and H (magnetic field intensity) cloud maps of the GPS module, and observe the electromagnetic effects of the GPS module submodules and the GPS module as a whole under the excitation of the 100MHz electromagnetic pulse source through the cloud maps. Fig. 9 and Fig.10 .

[0081] The electromagnetic topology model sets three sensitive points, one sensitive point is set at the sub-area V in the electromagnetic topology diagram, one sensitive point is set at the straight line of the signal line, and one sensitive point is set at the connection point between the signal line and the sub-module chip. The electromagnetic effects of the three sensitive points after being disturbed by strong electromagnetic pulses are quantitatively observed. Fig.11 The magnetic induction intensity of electromagnetic interference generated by the three sensitive points is 0-2.25*10 -8 T, during the simulation time of 0-0.40s, the electromagnetic interference in the sub-area and the straight line of the signal line is not much different from that at the connection point, and the electromagnetic interference in the sub-area and the straight line of the signal line is less than that at the connection point. After 0.40s, due to the continuous accumulation of electromagnetic effects, the electromagnetic interference in the sub-area and the straight line of the signal line and the electromagnetic interference at the connection point produce irregular oscillations, and the relative trends are similar. The overall electromagnetic interference trend of the system cannot be effectively estimated.

[0082] Use 500MHz pulse source to simulate again, and get the GPS module submodule and GPS module cloud map under 500MHz pulse source excitation, see Fig.12 and Fig.13 See also Fig.14 The magnetic induction intensity of electromagnetic interference generated by the three sensitive points is 0-1.50*10 -7 T, the electromagnetic effect under 100MHz electromagnetic pulse interference has increased significantly. During the simulation time 0-0.40s, the electromagnetic interference in the sub-area and signal line is not much different from that at the connection point, and the electromagnetic interference in the sub-area and signal line is also less than that at the connection point. After 0.40s, due to the continuous accumulation of electromagnetic effects, the electromagnetic interference in the sub-area and signal line and the electromagnetic interference at the connection point also produce irregular oscillations, with similar relative trends. The overall electromagnetic interference trend of the system cannot be effectively estimated.

[0083] Through simulation, it can be seen that the electromagnetic weak links of the GPS module are at the connection points between the signal line and the sub-module chip and at the corners of the signal line; the electromagnetic effect of the GPS module will be significantly aggravated after high-frequency excitation; the above experiment also verifies the rationality of constructing the electromagnetic topology map.

[0084] Corresponding to the electromagnetic effect analysis method of the UAV positioning system based on the electromagnetic topology map, this embodiment also proposes an electromagnetic effect analysis system of the UAV positioning system based on the electromagnetic topology map, which includes an electromagnetic topology and interference sequence map module, a transient response module, a physical model construction module and a simulation module, wherein:

[0085] The electromagnetic topology and interference sequence diagram module is used to decompose the coupling of strong electromagnetic pulses to the UAV positioning system into several coupling links using the electromagnetic topology method, and to establish the electromagnetic topology model and interference sequence diagram of the UAV positioning system.

[0086] The transient response module is used to derive the transient response of any submodule inside the drone GPS module to a strong electromagnetic pulse through the interference sequence diagram.

[0087] The physical model building module is used to set sensitive points based on the electromagnetic topology model and build the physical model of the drone GPS module using Solid Work software.

[0088] The simulation module is used to import the Step file generated by the Solid Work software using the ANSYS Maxwell simulation software, analyze the electromagnetic effects of the GPS module sub-modules, GPS module and preset sensitive points after being stimulated by different interference sources, and obtain the electromagnetic distribution characteristics and electromagnetic weak links of the UAV GPS module from the simulation analysis.

[0089] Unless otherwise specifically stated, the relative steps, numerical expressions and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present invention.

[0090] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0091] The units and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. A person of ordinary skill in the art may use different methods to implement the described functions for each specific application, but such implementation is not considered to be beyond the scope of the present invention.

[0092] Those skilled in the art will appreciate that all or part of the steps in the above method can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, such as a read-only memory, a disk or an optical disk. Optionally, all or part of the steps in the above embodiment can also be implemented using one or more integrated circuits, and accordingly, each module / unit in the above embodiment can be implemented in the form of hardware or in the form of software function modules. The present invention is not limited to any specific form of combination of hardware and software.

[0093] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for analyzing electromagnetic effects of a drone positioning system based on an electromagnetic topology map, characterized in that: Include: Using the electromagnetic topology method, the coupling of strong electromagnetic pulses to the UAV positioning system is decomposed into several coupling links, and the electromagnetic topology model and interference sequence diagram of the UAV positioning system are established; The transient response of any submodule inside the drone GPS module to a strong electromagnetic pulse is derived through the interference sequence diagram; Sensitive points were set based on the electromagnetic topology model, and the physical model of the drone GPS module was constructed using Solid Work software; The Step file generated by Solid Work software was imported using ANSYS Maxwell simulation software to analyze the electromagnetic effects of the GPS module sub-modules, GPS module and preset sensitive points after being stimulated by different interference sources. The electromagnetic distribution characteristics and electromagnetic weak links of the UAV GPS module were obtained from the simulation analysis.

2. The electromagnetic effect analysis method of the UAV positioning system based on the electromagnetic topology map according to claim 1 is characterized in that: The electromagnetic topological model for establishing the UAV positioning system includes: Based on the internal structure of the UAV GPS module, the electromagnetic topological model of the UAV GPS is established by using the topological graph theory through the graph composed of points and lines and the point and edge relationships represented by the graph; the naming rules in this model are: V represents the sub-area, S represents the shielding shell, V represents the shielding shell, and V represents the shielding shell. i，j The two subscripts represent the area within the i-th shielding shell and the j-th sub-area within the area. k，hi，j The four subscripts represent V k，h and V i，j The interface between the two sub-areas also represents the shielding shell.

3. The electromagnetic effect analysis method of the UAV positioning system based on the electromagnetic topology map according to claim 2 is characterized in that: In the interference sequence diagram, the conduction link is the signal transmission link when the GPS module is working normally. Electromagnetic interference enters the GPS module through two links. The interference enters the RF front end through the front door coupling and is coupled to the GPS module in a conduction manner. The interference also enters the inside of the GPS module through the back door coupling, and enters the conduction link in a field-line coupling manner after field-to-field coupling between regions.

4. The electromagnetic effect analysis method of the UAV positioning system based on the electromagnetic topology map according to claim 3 is characterized in that: The calculation formula for the transient response of any submodule in the drone GPS module to a strong electromagnetic pulse is as follows: Among them, ω p represents the coupling coefficient of different sub-regions in the electromagnetic topology, E i It represents the electric field strength in the area inside the i-th shielding shell, H i It represents the magnetic field strength in the area inside the i-th shielding shell; represents the transfer function from the hth sub-region within the kth shielding shell to the jth sub-region within the ith shielding shell, r represents the cross-region coupling path, and c represents the cross-conductor coupling path.

5. The electromagnetic effect analysis method of the UAV positioning system based on the electromagnetic topology map according to claim 4 is characterized in that: The response expression of the low noise amplifier in the drone GPS module to the strong electromagnetic pulse is as follows: Represents the electromagnetic pulse response of a strong electromagnetic pulse directly acting on a low noise amplifier through antenna coupling. Represents the coupling path through the filter housing and the filter, Representatives are coupled in through the LNA housing.

6. The electromagnetic effect analysis method of the UAV positioning system based on the electromagnetic topology map according to claim 4 is characterized in that: The response expression of the timing module in the drone GPS module to the strong electromagnetic pulse is as follows: Represents the electromagnetic pulse response of the timing module when a strong electromagnetic pulse is coupled to the antenna. Represents the coupling path through the filter housing and the filter, represents coupling into the LNA housing, Represents the interference effect of strong electromagnetic pulses on the timing module through digital circuits.

7. The electromagnetic effect analysis method of the UAV positioning system based on the electromagnetic topology map according to claim 6 is characterized in that: The response expression of the intermediate frequency module in the GPS module to the strong electromagnetic pulse is as follows: Based on the timing module Added The coupling path of the strong electromagnetic pulse is directly coupled from the digital circuit to the intermediate frequency module.

8. An electromagnetic effect analysis system for UAV positioning system based on electromagnetic topology map, characterized in that: It includes electromagnetic topology and interference sequence diagram module, transient response module, physical model building module and simulation module, among which: The electromagnetic topology and interference sequence diagram module is used to decompose the coupling of strong electromagnetic pulses to the UAV positioning system into several coupling links using the electromagnetic topology method, and to establish the electromagnetic topology model and interference sequence diagram of the UAV positioning system; The transient response module is used to derive the transient response of any submodule inside the drone GPS module to a strong electromagnetic pulse through the interference sequence diagram; The physical model building module is used to set sensitive points based on the electromagnetic topology model and build the physical model of the drone GPS module using Solid Work software; The simulation module is used to import the Step file generated by the Solid Work software using the ANSYS Maxwell simulation software, analyze the electromagnetic effects of the GPS module sub-modules, GPS module and preset sensitive points after being stimulated by different interference sources, and obtain the electromagnetic distribution characteristics and electromagnetic weak links of the UAV GPS module from the simulation analysis.

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