Method for positioning electromagnetic leakage signal through multi-source information fusion

Abstract

The invention relates to the technical field of electromagnetic safety protection, and discloses a method for positioning an electromagnetic leakage signal through multi-source information fusion, and the method comprises the following steps: in a selected space range, a user holds a single-end detector to scan the electromagnetic leakage signal in an environment in a movement process, and the scanning result is obtained; determining an electromagnetic leakage signal source direction through the electromagnetic leakage signal intensity; collecting motion attitude information of the single-ended detector through an inertial measurement unit, and reconstructing a motion track of the single-ended detector after filtering through a Kalman filter; constructing a space rectangular coordinate system by taking the initial position as an original point, selecting three positions in the motion trail to be combined with the initial position, and positioning the position of the electromagnetic leakage signal by utilizing a TDOA positioning algorithm; and positioning the position of the electromagnetic leakage signal again in combination with the direction of the electromagnetic leakage signal source determined in the movement process. According to the invention, single-end detection, an inertial measurement unit and a TDOA algorithm are combined, and accurate positioning of electromagnetic leakage signals without support of multiple base stations is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic safety protection, and in particular to a method for locating electromagnetic leakage signals by fusing multi-source information. Background Art

[0002] Information equipment inevitably radiates electromagnetic signals during operation. If these signals contain confidential information and are received and restored by other electronic devices, the confidential information will be leaked, posing a huge threat to information security.

[0003] At present, the detection and positioning methods of electromagnetic leakage signals in space can only determine the approximate area where the leakage signal is located, rather than the precise location. Therefore, how to efficiently and accurately detect whether there is electromagnetic signal leakage in space, and how to locate the electromagnetic leakage signal to achieve targeted key protection are urgent needs of electromagnetic safety protection in the current form. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a method for locating electromagnetic leakage signals by fusing multi-source information, thereby achieving accurate positioning of electromagnetic leakage signals.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted is as follows:

[0006] A method for locating electromagnetic leakage signals by multi-source information fusion comprises the following steps:

[0007] S1. Within the selected space, the user holds a single-ended detector to scan the electromagnetic leakage signal in the environment during movement, and determines the direction of the electromagnetic leakage signal source based on the electromagnetic leakage signal intensity;

[0008] S2, collecting the motion posture information of the single-ended detector through an inertial measurement unit, and reconstructing the motion trajectory of the single-ended detector after filtering through a Kalman filter;

[0009] S3, taking the initial position as the origin, constructing a spatial rectangular coordinate system, selecting three positions in the motion trajectory and combining them with the initial position, and using the TDOA positioning algorithm to locate the position of the electromagnetic leakage signal;

[0010] S4. Relocate the position of the electromagnetic leakage signal based on the direction of the electromagnetic leakage signal source determined during the movement.

[0011] As a further improvement of the present invention, in step S1, the direction of the electromagnetic leakage signal source is the direction when the electromagnetic leakage signal strength is maximum, and the maximum electromagnetic leakage signal strength is manifested as the maximum electromagnetic leakage signal amplitude in the time domain.

[0012] As a further improvement of the present invention, in step S2, the inertial measurement unit is an acceleration sensor and a gyroscope.

[0013] As a further improvement of the present invention, in step S3, the directions of the electromagnetic signal sources are determined at the three positions and the initial position.

[0014] As a further improvement of the present invention, in step S3, the TDOA positioning algorithm locates the position of the electromagnetic leakage signal in space through the coordinates of four points.

[0015] As a further improvement of the present invention, in step S3, the position of the electromagnetic leakage signal is located using the TDOA positioning algorithm, which specifically includes the following steps:

[0016] S3-1. Assume that the electromagnetic leakage signal positioning system consists of 4 points, 1 point is the initial position, and the other three are the positions in the motion trajectory. Take the initial position as the origin to construct a spatial rectangular coordinate system. The initial position is (0, 0, 0), position 1 is (x s1 ,y s1 , z s1 ), position 2 is (x s2 ,y s2 , z s2 ), position 3 is (x s3 ,y s3 , z s3 );

[0017] S3-2, the distance difference Δi between the target's initial position and the other three positions is measured (the distance difference is obtained by multiplying time by the speed of light), and the corresponding equation is:

[0018]

[0019] Simplified, we get:

[0020]

[0021] This equation also holds for the distances and; only when Δ i When the distance difference is l i >0, when Δ i is the distance and time l i <0;

[0022] S3-3, the three distance difference measurements form the following nonlinear equations:

[0023]

[0024] S3-4. Solve the equation group to obtain the position (x', y', z') of the electromagnetic leakage signal.

[0025] As a further improvement of the present invention, in step S4, the position of the electromagnetic leakage signal is located again in combination with the direction of the electromagnetic leakage signal source determined during the movement, which specifically includes the following steps:

[0026] S4-1. In the constructed spatial rectangular coordinate system, according to the direction of the electromagnetic signal source, list the linear equations of the four positions in the positioning system:

[0027] a1x+b1y+c1z+d1=0,

[0028] a2x+b2y+c2z+d2=0,

[0029] a3x+b3y+c3z+d3=0,

[0030] a4x+b4y+c4z+d4=0;

[0031] S4-2. The above equations are organized into 4 different sets of equations, and N (N≦4) solutions can be obtained. If N≤2, the single-ended detector is used again for detection, a new spatial rectangular coordinate system is constructed, and the linear equations are listed and solved again until N>2; if N>2, the average of the N solutions is obtained, and the calculation formula is as follows:

[0032]

[0033] S4-3. Combining the results of S3-4 and S4-2, the final electromagnetic leakage signal source position (x, y, z) can be obtained:

[0034]

[0035] The beneficial effects of the present invention are as follows: the present invention combines single-ended detection, an inertial measurement unit and a TDOA algorithm to realize electromagnetic leakage signal positioning without the support of multiple base stations, improves the accuracy, robustness and real-time performance of positioning, and solves the problem of how to efficiently and accurately comprehensively detect whether there is electromagnetic signal leakage in space, and how to locate the electromagnetic leakage signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0037] Figure 1 is a flow chart of the method of the present invention;

[0038] Figure 2 This is a schematic diagram of the electromagnetic leakage signal detected by a single-ended detector;

[0039] Figure 3Reconstruct the schematic diagram of the motion trajectory;

[0040] Figure 4 Schematic diagram of TDOA positioning algorithm. DETAILED DESCRIPTION

[0041] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0042] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0043] like Figure 1-4 As shown, a method for locating electromagnetic leakage signals by multi-source information fusion based on single-ended detection and inertial measurement includes a single-ended detection positioning process, a motion trajectory reconstruction process, a TDOA algorithm positioning process, and a positioning process combining single-ended detection with the TDOA positioning algorithm.

[0044] S1, single-ended detection and positioning process, including the following steps:

[0045] S1-1. Within the selected space, the user holds a single-ended detector and scans the electromagnetic leakage signal in the environment during movement;

[0046] S1-2. The single-ended detector can display the strength of the received electromagnetic signal on the screen. The strength of the electromagnetic leakage signal is determined by the amplitude of the electromagnetic leakage signal. The direction of the received electromagnetic leakage signal is determined according to the strength of the electromagnetic leakage signal.

[0047] S1-3. The user holds the single-ended detector and continues to move, continuously determining the direction of the electromagnetic leakage signal during the movement, and preliminarily locates the electromagnetic leakage signal.

[0048] S2, the motion trajectory reconstruction process includes the following steps:

[0049] S2-1, collecting acceleration and angular velocity data of the single-ended detector during movement through an acceleration sensor and a gyroscope;

[0050] S2-2, Kalman filtering is used to remove noise from the collected acceleration and angular velocity data to obtain more accurate data. Substituting the filtered acceleration data into the velocity vector update equation, we can get:

[0051] vn (t+dt)=v n (t)+a n (t) × dt;

[0052] Among them, v n (t) is the velocity vector at the current moment, a(t) is the acceleration vector at the current moment, v n (t+dt) is the updated velocity vector;

[0053] S2-3, use the three-axis angular velocity data to perform attitude estimation, the attitude estimation equation is:

[0054]

[0055] Among them, C i n (t) is the attitude conversion matrix at the current moment, I is the third-order unit matrix, and B(t) is a small-angle skew-symmetric matrix used to define the direction:

[0056]

[0057] Among them, ω xt ,ω yt and ω zt They are the three outputs of the triaxial angular velocity meter at time t;

[0058] S2.4. Use the velocity data to solve the position coordinates. The position vector update equation is:

[0059] p n (t+dt)=p n (t)+v n (t) × dt;

[0060] Among them, P n (t) is the position vector at the current moment, v n (t) is the velocity vector at the current moment, P n (t+dt) is the updated value of the position vector;

[0061] S3, the process of locating electromagnetic leakage signal using TDOA algorithm includes the following steps:

[0062] S3-1. Assume that the electromagnetic leakage signal positioning system consists of 4 points, 1 point is the initial position, and the other three are the positions in the motion trajectory. The initial position is (0, 0, 0), position 1 is (x s1 ,y s1 , z s1 ), position 2 is (x s2 ,y s2 , z s2 ), position 3 is (x s3,y s3 , z s3 );

[0063] S3-2, measure the distance difference Δ between the target's initial position and the other three positions i (The distance difference is obtained by multiplying time by the speed of light), then the corresponding equation is:

[0064]

[0065] Further simplification can be obtained as follows:

[0066]

[0067] This equation also holds for the distances and; only when Δ i When the distance difference is l i >0, when Δ i is the distance and time l i <0;

[0068] S3-3. For the three distance difference measurements, the following nonlinear equations can be formed:

[0069]

[0070] S3-4. Solving the equation group can obtain the position (x', y', z') of the electromagnetic leakage signal in space.

[0071] S4, the positioning process combining single-ended detection and TDOA algorithm includes the following steps:

[0072] S4-1. In the constructed spatial rectangular coordinate system, according to the direction of the electromagnetic signal source, list the linear equations of the four positions in the positioning system:

[0073] a1x+b1y+c1z+d1=0,

[0074] a2x+b2y+c2z+d2=0,

[0075] a3x+b3y+c3z+d3=0,

[0076] a4x+b4y+c4z+d4=0;

[0077] S4-2. The above equations are organized into 4 different sets of equations, and N (N≦4) solutions can be obtained. If N≤2, the single-ended detector is used again for detection, a new spatial rectangular coordinate system is constructed, and the linear equations are listed and solved again until N>2; if N>2, the average of the N solutions is obtained, and the calculation formula is as follows:

[0078]

[0079] S4-3. Combining the results of S3-4 and S4-2 can obtain the final electromagnetic leakage signal position (x, y, z), and the calculation formula is as follows:

[0080]

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, component splitting or combination, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for locating electromagnetic leakage signals by multi-source information fusion, characterized in that: The following steps are involved: S1. Within the selected space, the user holds a single-ended detector to scan the electromagnetic leakage signal in the environment during movement, and determines the direction of the electromagnetic leakage signal source based on the electromagnetic leakage signal intensity; S2, collecting the motion posture information of the single-ended detector through an inertial measurement unit, and reconstructing the motion trajectory of the single-ended detector after filtering through a Kalman filter; S3, taking the initial position as the origin, constructing a spatial rectangular coordinate system, selecting three positions in the motion trajectory and combining them with the initial position, and using the TDOA positioning algorithm to locate the position of the electromagnetic leakage signal; S4. Relocate the position of the electromagnetic leakage signal based on the direction of the electromagnetic leakage signal source determined during the movement.

2. The method for locating electromagnetic leakage signals by multi-source information fusion according to claim 1, characterized in that: In step S1 , the electromagnetic leakage signal source direction is the direction when the electromagnetic leakage signal strength is maximum. The maximum electromagnetic leakage signal strength is manifested as the maximum electromagnetic leakage signal amplitude in the time domain.

3. The method for locating electromagnetic leakage signals by multi-source information fusion according to claim 1, characterized in that: In step S2, the inertial measurement unit is an acceleration sensor and a gyroscope.

4. The method for locating electromagnetic leakage signals by multi-source information fusion according to claim 1, characterized in that: In step S3, the directions of the electromagnetic signal sources are determined at the three positions and the initial position.

5. The method for locating electromagnetic leakage signals by multi-source information fusion according to claim 1, characterized in that: In step S3, the TDOA positioning algorithm locates the position of the electromagnetic leakage signal in space through the coordinates of four points.

6. The method for locating electromagnetic leakage signals by multi-source information fusion according to claim 1, characterized in that: In step S3, the position of the electromagnetic leakage signal is located using the TDOA positioning algorithm, which specifically includes the following steps: S3-1. Assume that the electromagnetic leakage signal positioning system consists of 4 points, 1 point is the initial position, and the other three are the positions in the motion trajectory. Take the initial position as the origin to construct a spatial rectangular coordinate system. The initial position is (0, 0, 0), position 1 is (x s1 ,y s1 , z s1 ), position 2 is (x s2 ,y s2 , z s2 ), position 3 is (x s3 ,y s3 , z s3 ); S3-2, the distance difference Δi between the target's initial position and the other three positions is measured, and the corresponding equation is: Simplified, we get: This equation also holds for the distances and; only when Δ i When the distance difference is l i >0, when Δ i is the distance and time l i <0; S3-3, the three distance difference measurements form the following nonlinear equations: S3-4. Solve the equation group to obtain the position (x', y', z') of the electromagnetic leakage signal.

7. The method for locating electromagnetic leakage signals by multi-source information fusion according to claim 6 is characterized in that: In step S4, the position of the electromagnetic leakage signal is located again in combination with the direction of the electromagnetic leakage signal source determined during the movement, which specifically includes the following steps: S4-1. In the constructed spatial rectangular coordinate system, according to the direction of the electromagnetic signal source, list the linear equations of the four positions in the positioning system: a1x+b1y+c1z+d1=0, a2x+b2y+c2z+d2=0, a3x+b3y+c3z+d3=0, a4x+b4y+c4z+d4=0; S4-2. The above equations are organized into 4 different sets of equations, and N (N≦4) solutions can be obtained. If N≤2, the single-ended detector is used again for detection, a new spatial rectangular coordinate system is constructed, and the linear equations are listed and solved again until N>2; if N>2, the average of the N solutions is obtained, and the calculation formula is as follows: S4-3. Combining the results of S3-4 and S4-2, the final electromagnetic leakage signal source position (x, y, z) can be obtained:

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