A multi-channel device for measuring the magnetic field of a ship

Abstract

The present invention discloses a multi-channel device for measuring the magnetic field of a ship, which includes a magnetic field measurement probe unit and a magnetic field measurement host unit; a magnetic field measurement sensor device is arranged in the magnetic field measurement probe unit, and the magnetic field measurement sensor device includes an exciting coil, a measuring coil and an iron core; the exciting coil and the measuring coil are wound around the iron core at the same time; the magnetic field measurement host unit includes an analog circuit part, a band-pass filter circuit, an AC amplification circuit, a phase-sensitive detection circuit, a low-pass filter circuit, an integration amplification circuit, a limiting device, a phase shifter and a phase-locked loop; the present invention can measure the magnetic fields at different positions at different depths of the ship (including the starboard, port and keel) at one time, can display the magnetic field at a certain depth point, and the depth can be displayed through a depth sensor.

Description

Technical Field

[0001] The present invention belongs to the field of magnetic measurement, and particularly relates to a multi-channel device for measuring the magnetic field of a ship. Background Art

[0002] The magnetic field of a ship generally refers to the magnetic field generated by the ship in the surrounding space, which is the main physical field for various magnetic detection devices and underwater weapons to detect and attack. To resist the attack of underwater magnetic weapons and aerial magnetic detection, magnetic protection measures must be implemented for the ship, and accurately grasping the induced magnetic field of the ship is an important prerequisite for implementing magnetic protection measures.

[0003] At present, the electric and magnetic fields generated when ships with different draft depths pass by are different. The overall height of the existing device cannot be adjusted, reducing the flexibility and accuracy of measurement. At the same time, relying only on the chassis to contact the seabed, the device is prone to random shaking or flipping under the impact of ocean currents, affecting the measurement work. Summary of the Invention

[0004] To solve the above technical problems, the present invention proposes a multi-channel device for measuring the magnetic field of a ship, which is used to measure the magnetic field strength at different positions of the ship at different depths.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A multi-channel device for the magnetic field of a ship includes a magnetic measurement probe unit and a magnetic measurement host unit;

[0007] A magnetic measurement sensor device is arranged in the magnetic measurement probe unit. The magnetic measurement sensor device includes an exciting coil and an iron core; the magnetic measurement sensor device is also provided with a universal balance frame and a balancing device;

[0008] The magnetic measurement sensor device is also provided with a depth sensor for detecting the position depth of the measured magnetic field;

[0009] The magnetic measurement host unit includes an analog circuit part, a band-pass filter circuit, an AC amplifier circuit, a phase-sensitive detector circuit, a low-pass filter circuit, an integrating amplifier circuit, a limiting device, a phase shifter and a phase-locked loop;

[0010] The analog circuit part is used to generate a rectangular wave voltage with symmetric positive and negative half-cycles of a preset frequency, so as to generate an exciting current for the exciting coil device in the measured magnetic field, so that the exciting coil device generates an even harmonic induced electromotive force corresponding to the measured magnetic field; the analog circuit part includes a crystal oscillator, a frequency divider, a filter and an exciting circuit connected in sequence;

[0011] The analog circuit also provides a reference signal to the phase-sensitive detector circuit through the phase shifter and the phase-locked loop in sequence;

[0012] The excitation circuit is connected to the excitation coil in the magnetic measurement probe unit. By utilizing the non-linearity of the B-H curve of the iron core, under the combined action of the excitation current and the measured magnetic field, even harmonic induced electromotive forces corresponding to the measured magnetic field are generated in the excitation coil;

[0013] After the even harmonic induced electromotive forces pass through the band-pass filter circuit, a second harmonic voltage signal is obtained;

[0014] After the second harmonic voltage signal is subjected to AC amplification processing using the AC amplification circuit, a detection signal is generated through the phase-sensitive detection circuit;

[0015] After the detection signal passes through the low-pass filter circuit, the integration amplification circuit, and the limiting device, a DC voltage signal identical in magnitude and direction to the measured magnetic field is obtained.

[0016] Preferably, the multi-channel device further includes a negative feedback system;

[0017] The negative feedback system includes a feedback resistor, and the DC voltage signal is transmitted to the excitation coil in the magnetic measurement probe unit through the feedback resistor.

[0018] Preferably, the multi-channel device further includes a display system;

[0019] The display system includes an A / D circuit, a decoding device, and a display;

[0020] The A / D circuit is used to convert the DC voltage signal into a frequency signal proportional thereto;

[0021] The decoding device is used to perform counting, latching, and decoding on the frequency signal to obtain a digital signal;

[0022] The display is used to display the digital quantity represented by the digital signal.

[0023] Preferably, the magnetic measurement host unit further includes a channel selection unit;

[0024] When a plurality of the magnetic measurement probe units are connected to the magnetic measurement host unit, through the channel selection unit, the excitation circuit is connected to different magnetic measurement probe units, and at the same time the band-pass filter circuit is connected to the selected magnetic measurement probe unit.

[0025] The beneficial effects of the present invention are as follows:

[0026] A multi-channel device for measuring the magnetic field of a ship according to the present invention can measure the magnetic fields at different positions at different depths of the ship (including the port side, starboard side, and keel) at one time, while other products on the market can only measure the magnetic field at a single point of the ship once. It can display the magnetic field at a certain depth, and the depth can be displayed through a depth sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts:

[0028] Figure 1 It is a schematic structural diagram of a multi-channel device for measuring the magnetic field of a ship according to Embodiment 1 of the present invention;

[0029] Figure 2 It is a schematic structural diagram of a magnetic field measurement probe unit in a multi-channel device for measuring the magnetic field of a ship according to Embodiment 1 of the present invention;

[0030] Figure 3 It is a schematic flowchart of a method for measuring the magnetic field of a ship according to Embodiment 2 of the present invention;

[0031] Figure 4 It is a schematic structural diagram of a system for measuring the magnetic field of a ship according to Embodiment 3 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] Embodiment 1

[0034] As Figure 1 shown, it is a schematic structural diagram of a multi-channel device for the magnetic field of a ship according to Embodiment 1 of the present invention, including a magnetic field measurement probe unit and a magnetic field measurement host unit.

[0035] A magnetic field measurement sensor device is provided in the magnetic field measurement probe unit. The magnetic field measurement sensor device includes an excitation coil, a measurement coil, and an iron core. The excitation coil and the measurement coil are wound around the iron core at the same time. The magnetic field measurement sensor device is also provided with a universal balance frame and a balancing device. And the iron core must be placed along the magnetic field direction. The magnetic field measurement sensor device is also provided with a depth sensor for detecting the position depth of the magnetic field to be measured.

[0036] In this embodiment, the magnetic field measurement probe unit adopts the structure as shown in Figure 2 . Specifically, the magnetic field measurement probe unit has a conical cylinder structure. Its core parts are the magnetic field sensor and the depth sensor, which are used to convert the measured magnetic field and water depth into corresponding electrical signals. The magnetic field sensor is suspended in a watertight and pressure-resistant copper protective shell by a universal balance bracket, and the lead cable is led out from the cylinder. The cylinder is filled with silicone oil to increase damping. A balance device is provided below the magnetic field sensor to adjust the verticality of the sensor. The depth sensor is installed below the copper shell, and a handle is installed at the upper end of the copper shell to facilitate tying and lifting the nylon rope of the magnetic field measurement cylinder.

[0037] The magnetic field measurement host unit includes an analog circuit part, a band-pass filter circuit, an AC amplifier circuit, a phase-sensitive detector circuit, a low-pass filter circuit, an integration amplifier circuit, a limiting device, a phase shifter, and a phase-locked loop.

[0038] The analog circuit part is used to generate a rectangular wave voltage with positive and negative half-wave symmetry at a preset frequency of f Hz, so as to generate an exciting current in the exciting coil of the magnetic field measurement sensor device in the measured magnetic field H0, so that the measuring coil generates an even harmonic induced electromotive force corresponding to the measured magnetic field H0. The analog circuit part includes a crystal oscillator, a frequency divider, a filter, and an exciting circuit connected in sequence.

[0039] The analog circuit also provides a reference signal to the phase-sensitive detector circuit through a phase shifter and a phase-locked loop in sequence.

[0040] The exciting circuit is connected to the exciting coil of the magnetic field measurement sensor device inside the magnetic field measurement probe unit. Utilizing the nonlinearity of the B-H curve of the iron core, under the combined action of the exciting current and the measured magnetic field, an even harmonic induced electromotive force corresponding to the measured magnetic field H0 is generated in the measuring coil. Among them, the second harmonic voltage signal is the most obvious, and its magnitude is proportional to the magnitude of the measured magnetic field H0, and its phase changes with the direction of the measured magnetic field H0.

[0041] The even harmonic induced electromotive force passes through the band-pass filter circuit to obtain a second harmonic voltage signal.

[0042] After the second harmonic voltage signal is processed by the AC amplifier circuit for AC amplification, it passes through the phase-sensitive detector circuit to generate a detection signal.

[0043] After the detection signal passes through the low-pass filter circuit, the integration amplifier circuit, and the limiting device, a DC voltage signal identical to the magnitude and direction of the measured magnetic field is obtained.

[0044] Furthermore, this device also includes a display system. The display system includes an A / D circuit, a decoding device, and a display. The A / D circuit is used to convert the DC voltage signal into a frequency signal proportional thereto. The decoding device is used to count, latch, and decode the frequency signal to obtain a digital signal. The display is used to display the digital quantity represented by the digital signal.

[0045] Furthermore, in order to make the above data processing circuit operate in a zero magnetic state, the present invention also designs a negative feedback system. Specifically, the negative feedback system includes a feedback resistor, and the DC voltage signal is transmitted to the measurement coil in the magnetic field measurement probe unit through the feedback resistor.

[0046] Furthermore, the magnetic field measurement host unit further includes a channel selection unit. When a plurality of magnetic field measurement probe units are connected to the magnetic field measurement host unit, through the channel selection unit, the excitation circuit is connected to different magnetic field measurement probe units, and at the same time, the band-pass filter circuit is connected to the selected magnetic field measurement probe unit.

[0047] Embodiment 2

[0048] As Figure 3 shown, it is a schematic flowchart of the method for measuring the ship's magnetic field according to Embodiment 2 of the present invention, mainly including the following steps:

[0049] S1. Use the excitation current generating device to generate a rectangular wave voltage with positive and negative half-waves symmetric at a preset frequency of f Hz, so as to generate an excitation current in the excitation coil wound around the iron core in the measured magnetic field H0. The excitation coil, the measurement coil and the iron core together form a magnetic field measurement device, and the excitation coil and the measurement coil are both wound around the iron core. Utilizing the nonlinearity of the B-H curve of the iron core, under the combined action of the excitation current and the measured magnetic field H0, the measurement coil generates an even harmonic induced electromotive force corresponding to the measured magnetic field H0. Among them, the second harmonic voltage signal is the most obvious, and its magnitude is proportional to the magnitude of the measured magnetic field H0, and its phase changes with the direction of the measured magnetic field H0. In addition, the magnetic field measurement device is also provided with a balancing device, and the iron core must be placed along the magnetic field direction.

[0050] S2. Based on the even harmonic induced electromotive force, through band-pass filtering processing, obtain a second harmonic voltage signal proportional to the measured magnetic field H0.

[0051] S3. After performing AC amplification processing on the second harmonic voltage signal, generate a detection signal through a phase-sensitive detection circuit. The phase-sensitive detection circuit needs to rely on a reference signal sent by the excitation current generating device and subjected to phase shift and latching processing.

[0052] S4. After performing low-pass filtering processing and integral amplification processing on the detection signal, obtain a DC voltage signal whose magnitude and polarity exactly reflect the magnitude and direction of the measured magnetic field.

[0053] S5. At the same time, detect the position depth of the measured magnetic field through a depth measurement device.

[0054] S6. Use an A / D circuit to convert the DC voltage signal into a proportional frequency signal, then perform counting, latching, and decoding to obtain a digital signal, and use a display device to display the digital quantity represented by the digital signal.

[0055] Furthermore, in order to make the above data processing circuit work in a zero magnetic state, the present invention also designs a negative feedback process. Specifically, the DC voltage signal is sent to the measuring coil through a feedback resistor to form a negative feedback system.

[0056] Embodiment III

[0057] As Figure 4 shown, it is a schematic structural diagram of a ship magnetic field measurement system according to Embodiment III of the present invention, including an exciting current generating device, a magnetic field measuring device, a band-pass filtering device, a phase-sensitive demodulation device, a signal post-processing device, and a depth detection device.

[0058] The magnetic field measuring device includes an exciting coil, a measuring coil, and an iron core. The exciting coil and the measuring coil are wound around the iron core at the same time. At the same time, the magnetic field measuring device is provided with a balancing device, and the iron core must be placed along the magnetic field direction.

[0059] The exciting current generating device is used to generate a rectangular wave voltage with positive and negative half-cycles symmetric at a preset frequency of f Hz, so as to generate an exciting current in the exciting coil in the magnetic field measuring device in the measured magnetic field H0. Utilizing the non-linearity of the B-H curve of the iron core, under the combined action of the exciting current and the measured magnetic field H0, an even harmonic induced electromotive force corresponding to the measured magnetic field H0 is generated in the measuring coil in the magnetic field measuring device. Among them, the second harmonic voltage signal is the most obvious, and its magnitude is proportional to the magnitude of the measured magnetic field H0, and its phase changes with the direction of the measured magnetic field H0.

[0060] The band-pass filtering device is used to perform band-pass filtering on the even harmonic induced electromotive force to obtain a second harmonic voltage signal proportional to the measured magnetic field H0.

[0061] The phase-sensitive demodulation device is used to demodulate the second harmonic voltage signal after AC amplification processing according to the reference signal sent by the exciting current generating device and after phase shift and latching processing to generate a demodulation signal.

[0062] The signal post-processing device is used to perform low-pass filtering and integral amplification processing on the demodulation signal to obtain a DC voltage signal whose magnitude and polarity exactly reflect the magnitude and direction of the measured magnetic field.

[0063] At the same time, the depth detection device is used to detect the position depth of the measured magnetic field.

[0064] In addition, the measurement system further includes a display system. Specifically, the display system includes an A / D circuit, a decoding device, and a display device. The A / D circuit is used to convert a DC voltage signal into a frequency signal proportional thereto. The decoding device is used to count, latch, and decode the frequency signal to obtain a digital signal. The display device is used to display the digital quantity represented by the digital signal.

[0065] Furthermore, in order to make the above data processing circuit operate in a zero magnetic state, the present invention also designs a negative feedback process. Specifically, the negative feedback system includes a feedback resistor, and the DC voltage signal is transmitted to the measurement coil through the feedback resistor to form a negative feedback system.

[0066] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A multi-channel device for measuring the magnetic field of a ship, characterized in that: It includes a magnetic probe unit and a magnetic host unit; The magnetic sensor device is provided in the magnetic probe unit, and the magnetic sensor device includes an excitation coil, a measuring coil and an iron core; the excitation coil and the measuring coil are wound around the iron core at the same time; the magnetic sensor device is also provided with a universal balancing frame and a balancing device; The magnetic sensor device is also provided with a depth sensor for detecting the depth of the position of the measured magnetic field; The magnetic measuring host unit includes an analog circuit part, a bandpass filter circuit, an AC amplifier circuit, a phase-sensitive detection circuit, a low-pass filter circuit, an integral amplifier circuit, a limiter, a phase shifter and a phase lock; The analog circuit part is used to generate a rectangular wave voltage with positive and negative half-wave symmetry of a preset frequency, so as to generate an excitation current for the excitation coil in the magnetic sensor device in the measured magnetic field, so that the measuring coil generates an even harmonic induced potential corresponding to the measured magnetic field; the analog circuit part includes a crystal oscillator, a frequency divider, a filter and an excitation circuit connected in sequence; The analog circuit also provides a reference signal to the phase-sensitive detection circuit through the phase shifter and the phase lock in sequence; The excitation circuit is connected to the excitation coil in the magnetic probe unit, and utilizes the nonlinearity of the iron core B-H curve to generate an even harmonic induced potential corresponding to the magnetic field to be measured in the measuring coil under the combined action of the excitation current and the magnetic field to be measured; After the even harmonic induced potential passes through the bandpass filter circuit, a second harmonic voltage signal is obtained; After the AC amplification circuit is used to perform AC amplification processing on the second harmonic voltage signal, a detection signal is generated through the phase-sensitive detection circuit; After the detection signal passes through the low-pass filter circuit, the integral amplifier circuit and the amplitude limiting device, a DC voltage signal having the same magnitude and direction as the measured magnetic field is obtained; The magnetic measurement host unit also includes a channel selection unit; When the magnetic measuring host unit is connected to a plurality of magnetic measuring probe units, the excitation circuit is connected to different magnetic measuring probe units through the channel selection unit, and the bandpass filter circuit is connected to the selected magnetic measuring probe unit.

2. The multi-channel device for measuring the magnetic field of a ship according to claim 1, characterized in that: The multi-channel device also includes a negative feedback system; The negative feedback system includes a feedback resistor, and the DC voltage signal is transmitted to the exciting coil in the magnetic probe unit through the feedback resistor.

3. The multi-channel device for measuring the magnetic field of a ship according to claim 1, characterized in that: The multi-channel device also includes a display system; The display system includes an A / D circuit, a decoding device and a display; The A / D circuit is used to convert the DC voltage signal into a frequency signal proportional to the DC voltage signal; The decoding device is used to perform counting, latching and decoding on the frequency signal to obtain a digital signal; The display is used to display the digital quantity represented by the digital signal.

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