Array type electromagnetic detection emission synthesis excitation system and method

Abstract

The invention discloses an array type electromagnetic detection emission synthesis excitation system and method, and the system comprises an emission coil module which is formed by arranging a plurality of emission coils at certain intervals into a square, a circle or other structures; the emission control module is used for dynamically adjusting parameters of emission current according to detection requirements and environmental conditions and controlling the working state of the emission coil module; the time reference synchronization module is used for receiving time and position signals provided by a satellite, calibrating a clock and a position through a satellite positioning signal, and realizing synchronous emission of a plurality of coils; the time reference synchronization module sends satellite time and position signals to the emission control module; the emission control module generates an emission instruction according to a time reference and sends the emission instruction to each emission coil module; and each transmitting coil module simultaneously transmits a current pulse according to the received transmitting instruction to generate a stable electromagnetic field. Flexible arrangement modes such as unmanned aerial vehicle carrying or single-person carrying can be achieved.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic emission technology, and in particular to an array type electromagnetic detection emission synthesis excitation system and method. Background Art

[0002] In geophysical exploration, electromagnetic induction is often used to detect underground resources. By arranging a transmitting coil and a receiving coil on the ground, a pulse current is passed through the transmitting coil to generate a changing electromagnetic field. When this electromagnetic field penetrates the earth, it forms a secondary induced magnetic field underground. Underground conductors (such as mineral deposits or aquifers) respond to this induction field and generate secondary induced currents. The receiving coil receives the secondary induced current on the ground, analyzes its characteristics, and thus infers the distribution of underground resources.

[0003] Existing electromagnetic detection technologies mostly use a single large-area transmitting coil for electromagnetic transmission, but large-area coils are difficult to adapt to complex terrains, have high deployment costs, and are complex to operate. By using multiple small coils to combine transmission and achieve synthetic magnetic moments to simulate the transmission effect of a large-area coil, the flexibility and efficiency of the detection system can be improved. Summary of the invention

[0004] The purpose of the present invention is to provide an array-type electromagnetic detection emission synthesis excitation system and method, so as to achieve adjustment of multiple coils according to different terrain conditions, ensure synchronous emission, and improve the stability of magnetic field generation.

[0005] Technical solution: An array electromagnetic detection emission synthesis excitation system, including:

[0006] The transmitting coil module consists of multiple transmitting coils arranged in a square, circular or other structure at a certain interval, and is used to transmit electromagnetic signals;

[0007] The transmission control module dynamically adjusts the parameters of the transmission current according to the detection requirements and environmental conditions, and controls the working state of the transmission coil module;

[0008] The time reference synchronization module receives the time and position signals provided by the satellite, calibrates the clock and position through the satellite positioning signal, and realizes the synchronous transmission of multiple coils;

[0009] The time reference synchronization module sends the satellite time signal and position signal to the transmission control module; the transmission control module generates a transmission instruction according to the time reference and sends it to each transmission coil module; each transmission coil module simultaneously emits a current pulse according to the received transmission instruction to generate a stable electromagnetic field.

[0010] Furthermore, each transmitting coil module is equipped with an independent controller, which is used to control the current pulses in the transmitting coil module, including the current amplitude and frequency; each controller maintains a local clock through a crystal oscillator, and receives a time reference signal from a time reference synchronization module to periodically calibrate the crystal oscillator clock.

[0011] Furthermore, the arrangement of the transmitting coil modules is adjustable.

[0012] The method for implementing any of the above array-type electromagnetic detection emission synthesis excitation systems comprises the following steps:

[0013] S1, number the transmitting coil and perform position self-check through the satellite positioning system to confirm whether the positioning is completed;

[0014] S2, the satellite positioning system publishes coordinate information to each transmission control module, and the transmission control module arranges the transmission coil modules in an array according to the coordinate information, and the satellite positioning system detects whether the arrangement is successful again;

[0015] S3, after each transmitting coil module is ready, it waits for the release of the transmitting instruction; the transmitting control module receives the time reference signal generated by the time reference synchronization module, and realizes time synchronization through a high-precision crystal oscillator; the transmitting coil module simultaneously emits current pulses according to the transmitting instruction to generate a stable electromagnetic field;

[0016] S4, after the transmission is completed, the position of the transmitting coil module is updated again, adjusted to the next detection position, and a return signal is sent after traversing all detection positions, and the return is completed.

[0017] Furthermore, after the satellite positioning system performs time synchronization correction at time t0, the current is set to be turned on at the Nth pulse and turned off at the Mth pulse by counting the clock pulses output by the crystal oscillator, where M>N.

[0018] Compared with the prior art, the present invention has the following significant effects:

[0019] 1. The present invention uses multiple small coils, and the arrangement and parameters of the transmitting coils can be adjusted according to different terrain conditions, including the amplitude, frequency, waveform shape, etc. of the transmitting current, to simulate the transmitting effect of a large coil, and can adapt to complex surface structures, with greater flexibility in arrangement; if one of the small coils fails, it will not have a fatal impact on the overall detection, and it is easier to repair and replace;

[0020] 2. Use the satellite system to provide a time reference signal to ensure high-precision time synchronization, achieve synchronous transmission of multiple coils, and improve the stability of magnetic field generation; combine position information on the basis of time synchronization to achieve dynamic array layout planning of the transmitting coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the array electromagnetic detection emission synthesis excitation system;

[0022] Figure 2 The workflow diagram of the synthetic excitation system for array electromagnetic detection emission;

[0023] Figure 3 Schematic diagram of the magnetic field generated by the square-arranged coils;

[0024] Figure 4 Synchronous emission current waveform for multiple coils. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0026] like Figure 1 As shown, the array electromagnetic detection emission synthesis excitation system mainly includes the following parts:

[0027] The transmitting coil module has multiple coils arranged together in a straight line, square or circular structure. Each coil is fed with a current pulse to form an electromagnetic field.

[0028] Transmitting control module, each transmitting coil module is equipped with an independent controller, which is used to control the current pulse in the transmitting coil module, including the current amplitude and frequency. Each controller maintains the local clock through a high-precision crystal oscillator (i.e., crystal oscillator), and receives the time reference signal of the time reference synchronization module to regularly calibrate the crystal oscillator clock to ensure the synchronization of the transmission start time of each transmitting coil module.

[0029] The time reference synchronization module, the satellite receiver receives high-precision time signals from satellites such as Beidou or GPS, generates a unified time reference signal for the system, and distributes the time reference signal to the launch control module. The crystal oscillator in the launch control module receives and calibrates according to the time reference signal. The time reference signal can ensure the synchronization of the transmission of all coils and the stability of the magnetic field. The satellite receiver also receives position information for determining the coordinates of the launch coil module.

[0030] In the array electromagnetic detection and transmission system, the synchronous operation of multiple coils is crucial to generate a stable magnetic field. The system provides a unified time reference through satellite positioning systems such as Beidou or GPS, and combines high-precision crystal oscillators to maintain the stability of local crystal oscillator clocks in each controller, thereby achieving synchronous transmission of multiple coils. The introduction of satellite time signals solves the drift problem of local crystal oscillator clocks that may be caused by long-term operation, while high-precision crystal oscillators ensure stability in a short period of time.

[0031] When all controllers have been adjusted according to the time reference signal, the current in the coils will change synchronously, thereby ensuring the synchronous generation of the magnetic field.

[0032] The calculation formula for the magnetic moment M generated by a single coil is:

[0033] M=N·I·A (1)

[0034] Where N is the number of turns in the coil, I is the current in the coil, and A is the area of ​​the coil.

[0035] When multiple coils are arranged in a specific arrangement, their composite magnetic moment is the vector superposition of the magnetic moments of each coil. Multiple small coils can be arranged in a straight line, square, circle or other arrangement. The arrangement of the coils determines the distribution and strength of the magnetic field.

[0036] When multiple coils are arranged in a straight line, the composite magnetic moment is the direct vector superposition of the magnetic moments of each coil. Assuming there are n coils, the total magnetic moment is:

[0037]

[0038] Among them, M i is the magnetic moment of the ith coil, r i is the distance from the ith coil to the observation point, f(r i ) is as the distance r i The attenuation function is generally It means that the magnetic field decays inversely with the cube of the distance. If all coils have the same magnetic moment and the same spacing, and the spacing between each coil is d, the total magnetic moment can be expressed as:

[0039]

[0040] For n coils arranged in a square, the composite magnetic moment is the vector superposition of the magnetic moments of each coil. A coordinate system is established with the center point as the origin, and the position of each coil is (x i ,y i ), then the expression of the synthetic magnetic moment of the synthetic point (x, y) is:

[0041]

[0042] Among them, M i is the magnetic moment of each coil.

[0043] Formula (4) shows that as the distance between the coils increases, the synthetic magnetic moment of the outer coils about the center point decays as the cube of the distance.

[0044] In a circular arrangement, all coils are evenly distributed on a circle with a radius of r. Assuming there are n coils on the circle, the resultant magnetic moment at the center point is:

[0045] M3 total =n·M·(1 / r 3 ) (5)

[0046] Where M is the magnetic moment of a single coil.

[0047] The magnetic fields generated by different arrays of transmitting coils are vector-synthesized to simulate the effect of large-area transmitting coils. Different arrangements can be selected according to different terrains. If multiple coils are arranged in a square or circle with a distance of d, the synthetic magnetic moment M total The magnetic moment M of each coil can be i Superposition calculation:

[0048]

[0049] Among them, r i is the distance from each coil to the detection point, f(r i ,d) represents the function of magnetic field attenuation with distance.

[0050] like Figure 2 As shown, the working process of the array electromagnetic detection emission synthesis excitation system is as follows:

[0051] Step 1: First, number the transmitting coil and perform a position self-check through the satellite positioning system to confirm whether the positioning is completed;

[0052] Step 2: The satellite positioning system publishes coordinate information to each transmission control module. The transmission control module arranges the transmission coil modules in an array according to the coordinate information. The satellite positioning system detects whether the arrangement is successful again.

[0053] Step 3: After each transmitting coil module is ready, it waits for the release of the transmitting instruction. The transmitting control module receives the time reference signal generated by the time reference synchronization module and realizes time synchronization through a high-precision crystal oscillator. The transmitting coil module simultaneously emits current pulses according to the transmitting instruction to generate a stable electromagnetic field.

[0054] Step 4: After the transmission is completed, the position of the transmitting coil module is updated again, adjusted to the next detection position, and a return signal is sent after traversing all detection positions, and the return is completed.

[0055] The array electromagnetic detection emission synthetic excitation system transmits pulse signals through the satellite positioning system to maintain time synchronization and ensure the consistency of the emission waveform; after the satellite positioning system performs time synchronization correction at time t0, it counts the clock pulses output by the crystal oscillator and sets the current to turn on at the Nth pulse and turn off at the Mth pulse, M>N, thereby achieving precise time control of the emission current.

[0056] like Figure 3The figure shows the magnetic field superposition effect generated by multiple coils arranged in a 2×2 square.

[0057] In the array electromagnetic detection transmission synthetic excitation system, synchronous transmission is the core step to ensure that multiple transmitting coils can work together. Multiple coils are distributed in different positions. In order to avoid signal misalignment and data interference, the transmission must be accurately time synchronized. By using satellite positioning systems such as the Global Positioning System (GPS) or the Beidou Navigation System, accurate pulse signals can be provided as the time reference for the entire system.

[0058] The time reference synchronization module is used to receive pulse signals from the satellite positioning system and generate a time reference signal. The time reference signal can ensure that the pulse current is transmitted to the transmitting coil at the same time. In order to achieve this synchronization, the transmission control module uses a crystal oscillator to accurately control the switching frequency of the current. The crystal oscillator can convert the pulse signal into a more precise frequency control signal to ensure that the transmitting coil transmits electromagnetic pulses at the set frequency at the specified time point.

[0059] Multiple transmitting coil modules start working synchronously, and they will generate magnetic fields and transmit them underground at the same time. When the pulse current passes through the coil, the change in current generates an induced electromagnetic field on the ground. Since all transmitting coil modules transmit at the same time, these magnetic fields form a superposition effect on the ground, which helps to detect deep underground structures. The accuracy of synchronous transmission directly affects the superposition effect of the magnetic field. If the transmitting coil modules are not accurately synchronized, the detection signal may be distorted, affecting the final data analysis and identification of underground resources.

[0060] For the detailed steps of the array electromagnetic detection launch synthesis excitation system, take the UAV carrying the launch coil as an example:

[0061] Step A1: first number the transmitting coils to confirm the position of the transmitting coil module.

[0062] In step A2, the drone performs a self-check through the satellite positioning system. The satellite positioning system accurately locates the current position of each drone, including longitude, latitude and altitude, and monitors its changes in real time to ensure that the drone array detects according to the predetermined trajectory. At the same time, the time reference signal generated by the time reference synchronization module is used to synchronize the time of all transmitting coil modules, which is crucial for the synchronization of subsequent transmitting pulses. If the satellite positioning system self-check fails, the system will send an error signal; if successful, it will proceed to the next step.

[0063] Step A3, each drone carries a transmitting coil module and enters the working state, publishes the position coordinates to each transmitting control module, and the position of the transmitting coil module is determined according to the satellite system positioning, and the transmitting coil module is arranged according to the pre-set arrangement. The system determines whether the drone array is successfully arranged and ready. If it fails, necessary adjustments will be made, including fine-tuning the spatial position of the drone and correcting the coil direction.

[0064] Step A4, after each coil is ready, wait for the release of the transmission information. After the transmission information is released, confirm the time synchronization status of each transmitting coil to ensure that the electromagnetic pulse can be transmitted at the same time point. This synchronization is controlled by the crystal oscillator, which receives the time reference signal to ensure accurate timing control.

[0065] Step A5, after completing the time synchronization, all transmitting coil modules in the drone array generate current pulses simultaneously. The magnitude and frequency of the current are adjusted by a high-precision crystal oscillator to ensure that the current changes according to the predetermined magnitude and frequency and generates a corresponding electromagnetic field.

[0066] Step A6: After the launch, the drone array updates its position through the satellite positioning system, adjusts to the next detection position and launches again, ensuring that the drone moves to cover all target areas until the entire detection area is traversed.

[0067] Further, the working process of the crystal oscillator is explained:

[0068] The periodic signal generated by the crystal oscillator is divided or multiplied to output a clock signal of the target current frequency. By adjusting the signal generated by the crystal oscillator, the frequency change of the current can be made to meet the requirements. The time point of the current change is also controlled by the crystal oscillator. The periodic signal provided by the crystal oscillator is used as a timer, so that the current can change at a precise time point.

[0069] The frequency of the crystal oscillator can provide the system's reference clock signal and determine the time point when the current starts and stops. For multiple transmitting coils, they can be controlled by the same crystal oscillator signal so that they can synchronously transmit electromagnetic waves at the same time point.

[0070] like Figure 4 As shown in the figure, taking the synchronous transmission current of three coils as an example, it shows that multiple coils synchronously control the transmission current. The crystal oscillator outputs a clock signal with a fixed frequency. By counting these clock pulses, the timing of transmitting the current can be accurately controlled. The satellite performs time synchronization correction at time t0, setting the current to turn on at the Nth pulse (corresponding to time t1) and turn off at the Mth pulse (corresponding to time t2), so as to achieve precise time control of the transmission current.

Claims

1. An array type electromagnetic detection emission synthesis excitation system, characterized in that: include: The transmitting coil module consists of multiple transmitting coils arranged in a square, circular or other structure at a certain interval, and is used to transmit electromagnetic signals; The transmission control module dynamically adjusts the parameters of the transmission current according to the detection requirements and environmental conditions, and controls the working state of the transmission coil module; The time reference synchronization module receives the time and position signals provided by the satellite, calibrates the clock and position through the satellite positioning signal, and realizes the synchronous transmission of multiple coils; The time reference synchronization module sends the satellite time signal and position signal to the transmission control module; The transmitting control module generates a transmitting instruction according to the time reference and sends it to each transmitting coil module; each transmitting coil module simultaneously emits a current pulse according to the received transmitting instruction to generate a stable electromagnetic field.

2. The array type electromagnetic detection emission synthesis excitation system according to claim 1 is characterized in that: Each transmitting coil module is equipped with an independent controller, which is used to control the current pulses in the transmitting coil module, including the current amplitude and frequency; each controller maintains the local clock through a crystal oscillator, and receives the time reference signal of the time reference synchronization module to regularly calibrate the crystal oscillator clock.

3. The array type electromagnetic detection emission synthesis excitation system according to claim 1 is characterized in that: The arrangement of the transmitting coil modules is adjustable.

4. The method for implementing the array type electromagnetic detection emission synthesis excitation system according to any one of claims 1 to 3, characterized in that: The steps include: S1, number the transmitting coil and perform position self-check through the satellite positioning system to confirm whether the positioning is completed; S2, the satellite positioning system publishes coordinate information to each transmission control module, and the transmission control module arranges the transmission coil modules in an array according to the coordinate information, and the satellite positioning system detects whether the arrangement is successful again; S3, after each transmitting coil module is ready, it waits for the release of the transmitting instruction; the transmitting control module receives the time reference signal generated by the time reference synchronization module, and realizes time synchronization through a high-precision crystal oscillator; the transmitting coil module simultaneously emits current pulses according to the transmitting instruction to generate a stable electromagnetic field; S4, after the transmission is completed, the position of the transmitting coil module is updated again, adjusted to the next detection position, and a return signal is sent after traversing all detection positions, and the return is completed.

5. The method for implementing the array type electromagnetic detection emission synthesis excitation system according to claim 4 is characterized in that: After the satellite positioning system performs time synchronization correction at time t0, it counts the clock pulses output by the crystal oscillator and sets the current to turn on at the Nth pulse and turn off at the Mth pulse, where M>N.

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