Multi-channel device for measuring ship magnetic field

Abstract

The invention discloses a multi-channel device for measuring a ship magnetic field. The multi-channel device comprises a magnetism measuring probe unit and a magnetism measuring host unit, a magnetism measuring sensor device is arranged in the magnetism measuring probe unit and comprises an exciting coil, a measuring coil and an iron core; the exciting coil and the measuring coil are simultaneously wound on the iron core; the magnetic measurement host unit comprises an analog circuit part, a band-pass filter circuit, an alternating current amplification circuit, a phase sensitive detection circuit, a low-pass filter circuit, an integral amplification circuit, an amplitude limiting device, a phase shifter and a phase lock; according to the invention, magnetic fields (including a port, a starboard and a keel) at different positions of a ship at different depths can be measured at one time, the magnetic field for measuring the depth of a certain point can be displayed, and the depth can be displayed through the depth sensor.

Description

Technical Field

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

[0002] The ship's magnetic field usually refers to the magnetic field generated by the ship in the space around it. It is the main physical field used by various magnetic detection equipment and underwater weapons for detection and attack. In order to resist the attack of underwater magnetic weapons and aerial magnetic detection, magnetic protection measures must be implemented on the ship, and accurately grasping the ship's induced magnetic field is an important prerequisite for implementing magnetic protection measures.

[0003] At present, the electric and magnetic fields generated by ships of different draft depths are different, and the overall height of the existing device cannot be adjusted, which reduces the flexibility and accuracy of the measurement. At the same time, the device is easily shaken or flipped at will under the impact of the ocean current, affecting the measurement work. Summary of the invention

[0004] In order 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 at different depths of the ship.

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

[0006] A device for measuring a ship's magnetic field comprises a magnetic probe unit and a magnetic host unit;

[0007] The magnetic probe unit is provided with a magnetic sensor device, which includes an exciting coil and an iron core; the magnetic sensor device is also provided with a universal balancing frame and a balancing device;

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

[0009] 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;

[0010] The analog circuit part is used to generate a rectangular wave voltage with positive and negative half-wave symmetry of a preset frequency, thereby generating an excitation current for the excitation coil device in the measured magnetic field, so that the excitation coil device 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;

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

[0012] 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 excitation coil under the combined action of the excitation current and the magnetic field to be measured;

[0013] After the even harmonic induced potential passes through the bandpass filter circuit, a second harmonic voltage signal is obtained;

[0014] 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;

[0015] 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.

[0016] Preferably, the measuring device further comprises a negative feedback system;

[0017] 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.

[0018] Preferably, the measuring device further comprises 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 to the DC voltage signal;

[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 measuring host unit further includes a channel selection unit;

[0024] 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.

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

[0026] The present invention provides a multi-channel device for measuring the magnetic field of a ship, which can measure the magnetic field of different positions (including the port side, starboard side, and keel) at different depths of the ship at one time. Other products on the market can only measure the magnetic field of one point of the ship at a time. The magnetic field at the depth of a certain point can be displayed, and the depth can be displayed by a depth sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative labor:

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

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

[0030] Figure 3 This is a schematic flow chart of a method for measuring the magnetic field of a ship according to a second embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the structure of a system for measuring the magnetic field of a ship according to Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Embodiment 1

[0034] like Figure 1 , which is a schematic structural diagram of a device for measuring a ship's magnetic field according to a first embodiment of the present invention, including a magnetic measuring probe unit and a magnetic measuring host unit.

[0035] The magnetic probe unit is provided with a magnetic sensor device, which 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 balance frame and a balance device. The iron core must be placed along the direction of the magnetic field. The magnetic sensor device is also provided with a depth sensor for detecting the depth of the position of the measured magnetic field.

[0036] In this embodiment, the magnetic probe unit adopts Figure 2 The structure is shown. Specifically, the magnetic probe unit is a conical cylindrical structure, and 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 with a universal balance frame, and the lead cable is led out of the cylinder, which is filled with silicone oil to increase damping. A balancing 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 on the upper end of the copper shell to facilitate the nylon rope used to tie and pull the magnetic measuring cylinder.

[0037] The magnetic measuring host unit comprises an analog circuit part, a bandpass filtering circuit, an AC amplifying circuit, a phase-sensitive detection circuit, a low-pass filtering circuit, an integral amplifying circuit, a limiting device, a phase shifter and a phase lock.

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

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

[0040] The excitation circuit is connected to the excitation coil of the magnetic sensor device in the magnetic probe unit. By utilizing the nonlinearity of the iron core B-H curve, under the combined action of the excitation current and the measured magnetic field, an even harmonic induced potential 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 size is proportional to the size of the measured magnetic field H0, and its phase changes with the direction of the measured magnetic field H0.

[0041] The even harmonic induced potential is filtered through a bandpass filter circuit to obtain a second harmonic voltage signal.

[0042] After the second harmonic voltage signal is subjected to AC amplification processing by an AC amplifier circuit, a detection signal is generated by a phase-sensitive detection circuit.

[0043] After the detection signal passes through a low-pass filter circuit, an integral amplifier circuit and a limiting device, a DC voltage signal with the same magnitude and direction as the measured magnetic field is obtained.

[0044] Furthermore, the 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 a DC voltage signal into a frequency signal proportional to the DC voltage signal. 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 data processing circuit work 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 measuring coil in the magnetic probe unit through the feedback resistor.

[0046] Furthermore, the magnetic measuring host unit also includes a channel selection unit. When the magnetic measuring host unit is connected to several magnetic measuring probe units, the channel selection unit is used to connect the excitation circuit to different magnetic measuring probe units, and the bandpass filter circuit is connected to the selected magnetic measuring probe unit.

[0047] Embodiment 2

[0048] like Figure 3 FIG. 1 is a flow chart of a method for measuring a ship magnetic field according to a second embodiment of the present invention, which mainly includes the following steps:

[0049] S1. Use the excitation current generating device to generate a rectangular wave voltage with a preset frequency of fHz and symmetrical positive and negative half waves, so as to generate an excitation current for the excitation coil wound on the iron core in the measured magnetic field H0. The excitation coil, the measuring coil and the iron core together constitute a magnetic measuring device, and the excitation coil and the measuring coil are wound on the iron core at the same time. Using the nonlinearity of the iron core B-H curve, under the joint action of the excitation current and the measured magnetic field H0, the measuring coil generates an even harmonic induced potential corresponding to the measured magnetic field H0. Among them, the second harmonic voltage signal is the most obvious, and its size is proportional to the size of the measured magnetic field H0, and its phase changes with the direction of the measured magnetic field H0. In addition, the magnetic measuring device is also provided with a balancing device, and the iron core must be placed along the direction of the magnetic field.

[0050] S2. Based on the even harmonic induced potential, a second harmonic voltage signal proportional to the measured magnetic field H0 is obtained through bandpass filtering.

[0051] S3. After the second harmonic voltage signal is subjected to AC amplification processing, it is passed through a phase-sensitive detection circuit to generate a detection signal, wherein the phase-sensitive detection circuit needs to be based on a reference signal sent by the excitation current generating device and after the shifting and latching processing.

[0052] S4. After low-pass filtering and integral amplification processing are performed on the detection signal, a DC voltage signal is obtained, the magnitude and polarity of which just reflect the magnitude and direction of the measured magnetic field.

[0053] S5. At the same time, the depth of the position of the measured magnetic field is detected by a depth measuring device.

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

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

[0056] Embodiment 3

[0057] like Figure 4 As shown, it is a schematic diagram of the structure of the ship magnetic field measurement system of the third embodiment of the present invention, including an excitation current generating device, a magnetic measuring device, a bandpass filtering device, a phase-sensitive detection device, a signal post-processing device and a depth detection device.

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

[0059] The exciting current generating device is used to generate a rectangular wave voltage with a preset frequency of fHz and symmetrical positive and negative half waves, thereby generating an exciting current for the exciting coil in the magnetic measuring device in the measured magnetic field H0. By utilizing the nonlinearity of the iron core B-H curve, under the joint action of the exciting current and the measured magnetic field H0, the measuring coil in the magnetic measuring device generates an even harmonic induced potential corresponding to the measured magnetic field H0. Among them, the second harmonic voltage signal is the most obvious, and its size is proportional to the size of the measured magnetic field H0, and its phase changes with the direction of the measured magnetic field H0.

[0060] The bandpass filter device is used to perform bandpass filtering on the even-order harmonic induced potential to obtain a second harmonic voltage signal proportional to the measured magnetic field H0.

[0061] The phase-sensitive detection device is used to detect the second harmonic voltage signal after AC amplification based on the reference signal sent by the excitation current generating device and after term shifting and latching, so as to generate a detection signal.

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

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

[0064] In addition, the measurement system also 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 to the DC voltage signal. 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 data processing circuit work 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 measuring 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 are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all 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.

2. The multi-channel device for measuring the magnetic field of a ship according to claim 1, characterized in that: The measuring 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 measuring 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.

4. The multi-channel device for measuring the magnetic field of a ship according to claim 1, characterized in that: The magnetic measuring 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.

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