Mine emergency positioning method based on mechanical antenna

Abstract

The application discloses a mine emergency positioning method based on a mechanical antenna, comprising the following steps: measuring the magnetic induction intensity or the magnetic field intensity of a certain point in a coal mine underground through a base station according to the distribution information of an electromagnetic field in space; and calculating the position information of a target point based on the magnetic induction intensity or the magnetic field intensity. The application can more quickly and accurately determine the positions of trapped personnel and key equipment in an emergency rescue process, so that the rescue work can be carried out more quickly.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of low-frequency communication and mine emergency positioning, and particularly relates to a mine emergency positioning method based on a mechanical antenna. BACKGROUND

[0002] Since the electromagnetic wave transmission medium of the underground wireless communication is not air but a complex layered geological structure, the soil on the surface of the general crust has a high water content and various natural minerals, and the electromagnetic wave is seriously attenuated due to the high conductivity. In addition, the frequency of the electromagnetic wave has a great influence on its propagation in the ground, and the higher the frequency, the more serious the attenuation of the propagation in the ground. Therefore, it is difficult to realize the penetration communication in the mine by directly using the wireless communication system in the air on the ground.

[0003] At present, the main technologies for positioning personnel in the coal mine include infrared positioning technology, ultrasonic positioning technology, Bluetooth positioning, radio frequency identification positioning, ultra-wideband positioning, ZigBee positioning and WiFi positioning. However, these positioning methods are highly dependent on the positioning base station, and when an accident occurs, the positioning fails due to the destruction of the base station, and the position of the trapped personnel in the mine cannot be known. SUMMARY

[0004] The application mainly solves the problem that the conventional mine positioning system is easily invalid in the emergency state, the position of the trapped personnel cannot be known, and the rescue direction can only be determined by experience, resulting in slow rescue progress and even rescue failure due to the wrong direction.

[0005] To solve the above problems, the application provides the following scheme: a mine emergency positioning method based on a mechanical antenna, comprising:

[0006] According to the distribution information of the electromagnetic field in space, the magnetic induction intensity or the magnetic field intensity of a point in the coal mine underground is measured by a measurement base station, and the position information of the target point is calculated based on the magnetic induction intensity or the magnetic field intensity.

[0007] Preferably, the process of obtaining the distribution information of the electromagnetic field in space comprises,

[0008] The permanent magnet of the rotating permanent magnet mechanical antenna is rotated counterclockwise around the origin O1 in the y1o1z1 plane to obtain a first magnetic field distribution formula:

[0009]

[0010] wherein B0 is the residual magnetization intensity, j is an imaginary unit, is the wave number, r is the straight line distance between a point in space and the origin, and θ is the included angle between the straight line distance and the z axis in the three-dimensional coordinate system of space, is the included angle between the projection of the straight line distance in the oxy plane and the x axis, These are three mutually orthogonal direction vectors. The direction is along the direction of r. Draw a circle representing the distance from a point in space to the z-axis, where the direction of the tangent to the circle is defined by the right-hand rule along the z-axis. Direction is The direction.

[0011] Preferably, the process of obtaining spatial distribution information of the electromagnetic field further includes,

[0012] Because the frequency is extremely low, it is assumed that the entire positioning range is near-field communication. Therefore, the first magnetic field distribution formula is simplified to obtain the second magnetic field distribution formula:

[0013]

[0014] Where, μ0=4π×10 -7 N·A -2 Let m be the permeability in vacuum, and m0 be the magnetic dipole moment.

[0015] Preferably, the process of measuring the magnetic induction intensity or magnetic field intensity at a certain point underground in a coal mine using a measuring base station includes,

[0016] Using a coordinate system o1x1y1z1 with the source as the origin and a coordinate system o2x2y2z2 with the base station as the origin, in polar coordinates, based on the second magnetic field distribution formula, and utilizing coordinate system transformation, the polar coordinate system... The magnetic induction vectors in the three directions Derivation of the Cartesian coordinate system The magnetic induction vectors in the three directions (B) x1 B y1 B z1 ).

[0017] Preferably, the rectangular coordinate system The magnetic induction vectors in the three directions (B) x1 B y1 B z1 The expression is:

[0018]

[0019] Preferably, the process of calculating the location information of the target point based on the magnetic induction intensity or magnetic field intensity includes,

[0020] The magnetic flux density of a dynamic magnetic field is measured using a fluxgate meter to obtain fluxgate meter measurement data. and effective measurement data of fluxgate magnetometer

[0021] According to the fluxgate meter measurement data and the fluxgate magnetometer effective measurement data The position information of the target point is obtained based on a particle swarm optimization algorithm.

[0022] The fluxgate magnetometer effective measurement data The calculation expression is as follows:

[0023]

[0024] Wherein, is the inductance intensity along the x-axis direction measured by the fluxgate magnetometer, is the inductance intensity along the y-axis direction measured by the fluxgate magnetometer, is the inductance intensity along the z-axis direction measured by the fluxgate magnetometer, and V is the volume of the rotating permanent magnet.

[0025] The fluxgate magnetometer effective measurement data and the fluxgate magnetometer effective measurement data The process of obtaining the position information of the target point based on the particle swarm optimization algorithm includes,

[0026] Random particles are initialized based on the particle swarm optimization algorithm, and the optimal estimation solution is obtained by iteratively updating the speed and position of the particles. In each iteration process, the particles are updated by the first optimal estimation solution found by themselves and the second optimal estimation solution of the current entire particle swarm.

[0027] Preferably, the process of updating the particles by the first optimal estimation solution found by themselves and the second optimal estimation solution of the current entire particle swarm includes,

[0028] Based on a search space of D dimensions and a colony consisting of n particles, each particle is represented as a D-dimensional vector x i =(x i1 , x i2 , … x iD ), i=1, 2, …n, wherein i=1, 2, …n, each particle corresponds to a D-dimensional velocity vector v i =(v i1 , v i2 , … v iD ), i=1, 2, …n;

[0029] The current optimal estimation solution of the particle i is P best =(p i1 , P i2 , … P iD ), i=1, 2, …n, and the optimal estimation solution found by the entire particle swarm is g best =(P g1 , P g2 , … PgD );

[0030] wherein the expression for updating the velocity and position of the particle is:

[0031]

[0032]

[0033] wherein c1 and c2 are learning factors, the learning factors determining the influence of the particle itself and other particles on the particle; w is an inertia factor, and r1 and r2 are random numbers in the range of (0, 1), i = 1, 2, … n is the velocity of the particle at the k (k = 1, 2, … m) th updating or iteration.

[0034] Compared with the prior art, the present application has the following advantages and technical effects:

[0035] The mine emergency positioning method based on the mechanical antenna fully utilizes the strong penetration characteristics of low-frequency electromagnetic waves, and can realize positioning of the miners and underground equipment in an emergency state. After the positioning data is calculated, the rescue personnel can formulate the best rescue strategy according to the position information of the trapped personnel, so as to achieve the purpose of reducing casualties.

[0036] By using the method, the positions of the trapped personnel and key equipment can be determined more quickly and accurately in the emergency rescue process, and the rescue work can be carried out more quickly. BRIEF DESCRIPTION OF DRAWINGS

[0037] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The embodiments of the present application illustrated in the drawings and their descriptions are used to explain the present application and are not intended to limit the present application. In the drawings:

[0038] Figure 1 is a schematic diagram of trapped personnel and search and rescue in a mine after collapse according to an embodiment of the present application;

[0039] Figure 2 is a rotating directional diagram of a rotating permanent magnet antenna according to an embodiment of the present application;

[0040] Figure 3 is a schematic diagram of a three-dimensional space positioning coordinate system according to an embodiment of the present application;

[0041] Figure 4 is a detailed position diagram of a positioning origin according to an embodiment of the present application. DETAILED DESCRIPTION

[0042] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0043] It should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that here.

[0044] As shown in the figure, the mechanical antenna-based mine emergency positioning method provided by the application specifically comprises the following steps, Figure 1

[0045] According to the distribution information of the electromagnetic field in space, the magnetic induction intensity or the magnetic field intensity of a certain point in the coal mine underground is measured by a measurement base station, and the position information of the target point is calculated based on the magnetic induction intensity or the magnetic field intensity.

[0046] Further optimization scheme, the process of obtaining the distribution information of the electromagnetic field in space includes,

[0047] As shown in the figure, the permanent magnet of the rotating permanent magnet mechanical antenna is rotated counterclockwise around the origin O1 in the y1o1z1 plane to obtain a first magnetic field distribution formula: Figure 2

[0048]

[0049] Wherein, B0 is the residual magnetization, j is the imaginary unit, is the wave number, r is the straight line distance from a point in space to the origin, θ is the included angle between the straight line distance and the z axis in the three-dimensional coordinate system of space, is the included angle between the projection of the straight line distance in the oxy plane and the x axis, is three mutually orthogonal direction vectors, the direction along the direction of r, is the distance from a point in space to the z axis as a circle, wherein the tangent direction of the circle is the direction, and the direction is defined according to the right-hand rule along the z axis,

[0050] Further optimization scheme, because the frequency is extremely low, it is considered that the positioning range is all near field communication, the first magnetic field distribution formula is simplified to obtain a second magnetic field distribution formula:

[0051]

[0052] Wherein, μ0=4π×10 -7 N·A -2 is the permeability in vacuum, and m0 is the magnetic dipole moment.

[0053] ​​​​Further optimization scheme, the process of measuring the magnetic induction intensity or the magnetic field intensity of a certain point in the coal mine underground by the base station includes,

[0054] As shown in Figure 3 , by taking the signal source as the origin of the coordinate system o1x1y1z1 and taking the measurement base station as the origin of the coordinate system o2x2y2z2, in the representation of polar coordinate system, based on the second magnetic field distribution formula, the magnetic induction intensity vector of three directions of the polar coordinate system is derived to obtain the magnetic induction intensity vector of three directions of the rectangular coordinate system , (B x1 , B y1 , B z1 ) is obtained as follows:

[0055]

[0056] Further optimization scheme, the process of calculating the position information of the target point based on the magnetic induction intensity or the magnetic field intensity includes,

[0057] When measuring the magnetic induction intensity of the dynamic magnetic field by the fluxgate, the fluxgate measurement data and the fluxgate effective measurement data

[0058] According to the fluxgate measurement data and the fluxgate effective measurement data , the position information of the target point can be obtained by solving the solution of the following equation based on the particle swarm optimization algorithm.

[0059]

[0060] Further optimization scheme, the calculation expression of the fluxgate effective measurement data is:

[0061]

[0062] Wherein, is the induction intensity along the x-axis direction measured by the fluxgate, is the induction intensity along the y-axis direction measured by the fluxgate, is the induction intensity along the z-axis direction measured by the fluxgate, and V is the volume of the rotating permanent magnet.

[0063] Further optimization scheme, according to the fluxgate measurement data and the fluxgate effective measurement data , the process of calculating the position information of the target point based on the particle swarm optimization algorithm includes,

[0064] Random particles are initialized based on the particle swarm optimization algorithm, and the optimal estimation solution is obtained by iteratively updating the speed and position of the particles. In each iteration process, the particles are updated by the first optimal estimation solution found by themselves and the second optimal estimation solution found by the whole particle swarm.

[0065] In the embodiment, a D-dimensional search space is composed of a colony of n particles. Each particle is represented as a D-dimensional vector x i = (x i1 , x i2 ,... x iD ), i = 1, 2,... n, where i = 1, 2,... n. In addition, each particle also has a corresponding D-dimensional velocity vector v i = (v i1 , v i2 ,... v iD ), i = 1, 2,... n. The current optimal estimation solution of particle i is P best = (P i1 , P i2 ,... P iD ), i = 1, 2,... n, and the optimal estimation solution found by the whole particle swarm is g best = (P g1 , P g2 ,... P gD ). When updating the speed and position of the particles, the following formula is used:

[0066]

[0067]

[0068] where c1 and c2 are learning factors, which determine the influence of the particle itself and other particles on the particle; w is an inertia factor, r1 and r2 are random numbers in the range of (0, 1), i = 1, 2,... n is the speed of the particle at the k (k = 1, 2,... m)th update or iteration.

[0069] The parameters of the PSO algorithm used in the embodiment are as follows:

[0070] n = 40, c1 = 3, c2 = 3, w = 0.01, m = 500,

[0071] The pseudo code of the algorithm is listed as shown in Table 1 for clearer representation:

[0072] Table 1

[0073]

[0074] The setting of learning factors has a decisive influence on the search behavior and convergence speed of the estimated solution. If c1 is set to be larger, the estimated solution will search in a local range, and if c2 is set to be larger, the estimated solution will converge too early. In order to balance the relationship between global search and local search, the PSO-X model of the embodiment introduces a compression factor φ to achieve more flexible and controllable estimated solution search and algorithm convergence effect. Through appropriate parameter selection, this method can ensure that the PSO algorithm can converge within a reasonable time.

[0075]

[0076]

[0077] Wherein, c1+c2>4, c1=3 and c2=3.

[0078] Further optimization scheme, mine collapse after the positioning method is as follows:

[0079] (1) according to the probe placement position, the probe is placed at position 1, position 2, position 3, position 4 and the distance and magnetic induction intensity are measured. Figure 1

[0080] (2) the origin coordinates of positioning are the measured base station position of position 1, the accurate coordinate origin of the measured base station is shown as in the figure, and the coordinate position of the rotating permanent magnet type mechanical antenna is the rotating center. Figure 4

[0081] (3) after recording the data, the data is imported into the above algorithm, and the position information of the repositioned target point can be obtained.

[0082] The mechanical antenna used in the application uses mechanical method to excite magnetic dipole, and generates low-frequency electromagnetic wave. According to the electromagnetic wave attenuation formula, the electromagnetic wave attenuates more slowly when the frequency is low, so it has strong penetration and can directly penetrate the buried layer. In the emergency state, signal transmission can be realized without base station, and then positioning is realized.

[0083] The above is only the preferred specific embodiment of the application, but the protection scope of the application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the application, which should be covered in the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.​​

Claims

1. A method for emergency positioning in mines based on mechanical antennas, characterized in that, include: Based on the spatial distribution information of electromagnetic fields, the magnetic induction intensity or magnetic field intensity of a certain point in a coal mine is measured by a measurement base station, and the location information of the target point is calculated based on the magnetic induction intensity or magnetic field intensity. The process of obtaining information about the spatial distribution of electromagnetic fields includes, By rotating the permanent magnet of the mechanical antenna, the magnetic field distribution formula is obtained as follows: The first magnetic field distribution formula is obtained by rotating the permanent magnet of the mechanical antenna counterclockwise around the origin O1 in the plane. in, The remanent magnetization is given by j, which is the imaginary unit. For wave number, The straight-line distance between a point in space and the origin. The straight-line distance and the three-dimensional coordinate system in space The included angle of the axis, The straight-line distance is in Projection in the plane and The included angle of the axis, , , These are three mutually orthogonal direction vectors. Direction along direction, For a point in space Draw a circle with respect to the axis, where the direction of the tangent to the circle is determined by the direction along the axis. The right-hand rule for axes states that, Direction is The direction.

2. The emergency positioning method for mines based on mechanical antennas according to claim 1, characterized in that, The process of obtaining information about the spatial distribution of electromagnetic fields also includes, Because the frequency is extremely low, it is assumed that the entire positioning range is near-field communication. Therefore, the first magnetic field distribution formula is simplified to obtain the second magnetic field distribution formula: wherein is the magnetic permeability in vacuum, is the magnetic dipole moment.

3. The emergency positioning method for mines based on mechanical antennas according to claim 1, characterized in that, The process of measuring the magnetic induction intensity or magnetic field intensity at a certain point underground in a coal mine using a measuring base station includes the following steps: Using a coordinate system with the source of the signal as the origin and a coordinate system with the measurement base station as the origin In polar coordinates, based on the second magnetic field distribution formula, and using coordinate transformation, from polar coordinates... The magnetic induction vectors in the three directions Derivation of the Cartesian coordinate system The magnetic induction vectors in the three directions .

4. The emergency positioning method for mines based on mechanical antennas according to claim 3, characterized in that, The rectangular coordinate system The magnetic induction intensity vector of the three directions The expression is: wherein is the magnetic permeability in vacuum, is the magnetic dipole moment.

5. The emergency positioning method for mines based on mechanical antennas according to claim 1, characterized in that, The process of calculating the location information of the target point based on the magnetic induction intensity or magnetic field intensity includes: The magnetic induction intensity of the dynamic magnetic field is measured by using a fluxgate meter to obtain fluxgate meter measurement data and effective fluxgate meter measurement data ; According to the fluxgate meter measurement data And the fluxgate meter effective measurement data The position information of the target point is obtained based on a particle swarm optimization algorithm.

6. The emergency positioning method for mines based on mechanical antennas according to claim 5, characterized in that, The fluxgate magnetometer effective measurement data The calculation expression is: wherein, is the induced intensity in the x-axis direction measured by the fluxgate meter, is the induced intensity in the y-axis direction measured by the fluxgate meter, is the induced intensity in the z-axis direction measured by the fluxgate meter, and V is the volume of the rotating permanent magnet.

7. The emergency positioning method for mines based on mechanical antennas according to claim 5, characterized in that, According to the fluxgate meter measurement data And the fluxgate meter effective measurement data The process of obtaining the position information of the target point based on the particle swarm optimization algorithm includes, Random particles are initialized based on the particle swarm optimization algorithm. The optimal estimated solution is obtained by iteratively updating the particle's velocity and position. In each iteration, the particle updates itself using its first optimal estimated solution and the current second optimal estimated solution of the entire particle swarm.

8. The emergency positioning method for mines based on mechanical antennas according to claim 7, characterized in that, The process by which a particle updates its estimate using its own first optimal estimate and the current second optimal estimate of the entire particle swarm includes the following steps: Based on a search space of D dimensions and a colony consisting of n particles, each particle is represented as a D-dimensional vector x i = (x i1 , x i2 ,... x iD ), i = 1, 2,... n, each particle corresponds to a D-dimensional velocity vector v i = (v i1 , v i2 ,... v iD ), i = 1, 2,... n; The current optimal estimation solution of particle i is P best = (P i1 , P i2 ,... P iD ), i = 1, 2,... n, and the optimal estimation solution currently found by the whole particle group is g best = (P g1 , P g2 ,... P gD ); The expressions for updating the particle's velocity and position are as follows: wherein, and is a learning factor, the learning factor determines the particle itself and the influence of other particles on the particle; w is an inertia factor, and is a random number in the range of (0, 1), vi, i = 1, 2,... n is the speed of the particle at the kth update or iteration, k = 1, 2,... m.

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