Multi-probe omnidirectional atomic magnetometer and magnetic induction intensity measurement method

Abstract

The invention discloses a multi-probe omnidirectional atomic magnetometer and a magnetic induction intensity measurement method. The multi-probe omnidirectional atomic magnetometer comprises three atomic magnetometer probes, a fluxgate sensor probe, an atomic magnetometer excitation acquisition module, a fluxgate sensor excitation acquisition module and a data processing module, the atomic magnetometer excitation acquisition module excites three atomic magnetometer probes and acquires the magnetic induction intensity of the position; the fluxgate sensor excitation acquisition module excites a fluxgate sensor probe and acquires three components of magnetic induction intensity of the position; the data processing module calculates included angles between the external magnetic field and the three atomic magnetometer probes, and magnetic field signals measured by the atomic magnetometer closest to 45 degrees are selected and output; when the probes are switched, the output value of the magnetic induction intensity of the previous probe is taken as the reference for continuous output, so that the omnidirectional continuous measurement of the magnetic induction intensity is realized; the problem that in the prior art, no-blind-area measurement of the atom magnetometer cannot be achieved can be solved.

Description

Technical Field

[0001] The invention belongs to the technical field of atomic magnetometer sensors, and in particular relates to an omnidirectional atomic magnetometer with multiple probes and a method for measuring magnetic induction intensity. Background Art

[0002] When measuring magnetic fields between large latitudes or large dynamic attitude angle changes, the atomic magnetometer used is required to adapt to the measurement of magnetic fields at different angles, that is, the atomic magnetometer is required to have the characteristic of no blind spots. At present, mature atomic magnetometers are mainly optically pumped magnetometers, including tracking helium optical pumps and self-excited cesium optical pumps. Helium optical pump magnetometers and cesium optical pump magnetometers are Mz tracking optical pump magnetometers and self-excited Mx optical pump magnetometers, respectively. Both types of optically pumped magnetometers have working dead zones. For self-excited optical pump magnetometers, when the magnetic field is perpendicular or parallel to the optical axis, they cannot work normally, that is, there are two dead zones in the equatorial plane and the poles, and the working area is generally 15° to 75°; for Mz tracking optical pump magnetometers, when the magnetic field is perpendicular to the optical axis, the optical pump cannot work, there is a dead zone, and the working area is generally 15° to 90°.

[0003] Therefore, the present invention proposes a method of using an atomic magnetometer as a measurement sensor, placing three probes at a certain angle to ensure that one probe is in a normal working state at all times, thereby achieving magnetic induction intensity measurement without blind spots. Summary of the invention

[0004] In view of this, the present invention provides a multi-probe omnidirectional atomic magnetometer and a magnetic induction intensity measurement method, which can solve the problem that the atomic magnetometer cannot be measured without blind spots in the prior art.

[0005] The technical solution for implementing the present invention is as follows:

[0006] A multi-probe omnidirectional atomic magnetometer, comprising a magnetometer sensing unit and a magnetometer excitation acquisition unit, wherein:

[0007] The magnetometer sensing unit is used to convert the magnetic induction intensity signal into an electrical signal;

[0008] The magnetometer excitation acquisition unit is used to drive the magnetometer sensing unit to collect signals and perform signal processing.

[0009] Furthermore, the magnetometer sensing unit specifically includes:

[0010] Three atomic magnetometer probes are used to transmit magnetic fields at any angle and convert magnetic induction intensity signals into photoelectric signals. The optical axes of the three probes form a 45° angle with each other in space.

[0011] A fluxgate sensor probe for three-component measurement of magnetic fields, with the fluxgate sensor probe placed in the middle of three atomic magnetometer probes.

[0012] Furthermore, the magnetometer excitation and acquisition unit specifically includes:

[0013] An atomic magnetometer signal excitation and acquisition circuit for exciting the atomic magnetometer to collect the magnitude signal of the magnetic induction intensity and converting the analog signal into a digital signal through frequency counting for subsequent data processing;

[0014] A fluxgate sensor signal excitation and acquisition circuit for exciting the fluxgate sensor to collect the three-component signal of the magnetic induction intensity and facilitating subsequent data processing through analog-to-digital conversion;

[0015] A data processing circuit that outputs the effective values of the collected multiple magnetic induction intensity signals through algorithms.

[0016] A method for measuring the magnetic induction intensity of an omnidirectional atomic magnetometer with multiple probes, including the following steps:

[0017] Step 1: Start the device for preheating;

[0018] Step 2: The three atomic magnetometer probes and the fluxgate sensor probe respectively collect signals;

[0019] Step 3: Calculate the included angles between the three atomic magnetometer probes and the magnetic field vector through the fluxgate;

[0020] Step 4: Determine the atomic magnetometer probe at the optimal working angle through the fluxgate, output the magnetic field signal collected by this probe, and calculate the data signal quality through the data processing circuit;

[0021] Step 5: If the data signal quality is okay, perform signal output and display. If the data signal quality is problematic, give an alarm;

[0022] Step 6: When the angle between the magnetic field and the magnetometer sensing unit changes, recalculate the optimal working angle and perform non-jumping probe switching through difference compensation based on the previous data.

[0023] Furthermore, when the current probe jumps out of the optimal working range and probe switching is performed, to ensure the normal execution of magnetic anomaly detection work, it is necessary to ensure that the magnetic field signal does not jump. The current magnetic field is B n , the previous magnetic field is B n-1 , to ensure that the magnetic field does not jump, reduce the magnetic induction intensity value after switching by B n -B n-1 , to achieve omnidirectional and continuous measurement of the magnetic induction intensity.

[0024] Beneficial effects:

[0025] 1. Traditional atomic magnetometers have a measurement blind spot of at least 10° when the magnetic field is perpendicular or parallel to the optical axis of the sensing unit. The present invention integrates multiple probes to cover the measurement blind spot.

[0026] 2. The present invention places three probes at a certain angle to ensure that one probe is in a normal working state at all times, thus achieving the purpose of having no blind spot.

[0027] 3. The present invention compensates for the measurement differences of the three probes, so that there is no data jump when the device switches probes, and realizes the omnidirectional continuous measurement of magnetic induction intensity. Description of the Drawings

[0028] Figure 1 It is a schematic diagram of the principle of an omnidirectional atomic magnetometer with multiple probes.

[0029] Figure 2 It is a schematic diagram of the angle of the sensing unit.

[0030] Figure 3 It is a schematic diagram of the sensing unit of the magnetometer.

[0031] Among them, 1-3 are atomic magnetometer probes, 4 is a fluxgate sensor probe, 5 is an atomic magnetometer excitation acquisition circuit, 6 is a fluxgate sensor excitation acquisition circuit, and 7 is a data processing circuit. Detailed Embodiment

[0032] The following combines the drawings and gives embodiments to describe the present invention in detail.

[0033] The present invention provides an omnidirectional atomic magnetometer with multiple probes, as Figure 1 shown, including: three atomic magnetometer probes 1, 2, 3, a fluxgate sensor probe 4, an atomic magnetometer excitation acquisition circuit 5, a fluxgate sensor excitation acquisition circuit 6, and a data processing circuit 7. As Figure 3 shown, the optical axes of the three atomic magnetometer probes form an angle of 45° with each other in space to ensure that at least one optically pumped probe is working normally. The fluxgate sensor probe is placed in the middle of the three atomic magnetometer probes to measure the direction of the magnetic field, so as to determine which atomic magnetometer probe's measurement data to select.

[0034] The excitation and acquisition circuit of the atomic magnetometer excites three atomic magnetometer probes and acquires the magnitude of the magnetic induction intensity at the location; the excitation and acquisition circuit of the fluxgate sensor excites the fluxgate sensor probe and acquires the three components of the magnetic induction intensity at the location; the data processing circuit calculates the angles between the external magnetic field and the three atomic magnetometer probes, selects the magnetic field signal measured by the atomic magnetometer closest to 45° for output; when switching probes, the output continues based on the magnetic induction intensity output value of the previous probe, realizing the omnidirectional continuous measurement of the magnetic induction intensity.

[0035] The method for measuring the magnetic induction intensity of the omnidirectional atomic magnetometer with multiple probes proposed by the present invention is specifically described in the following implementation steps:

[0036] (1) Figure 3 Among them, the optical axes of the three atomic magnetometers form a 45° angle in space, and the fluxgate sensor probe is placed at the coordinate origin;

[0037] (2) Figure 2 Among them, the excitation and acquisition circuit 5 of the atomic magnetometer respectively excites the three atomic magnetometer probes 123 and acquires the magnitudes of the magnetic induction intensities at the locations, which are B1, B2, and B3 respectively;

[0038] (3) The excitation and acquisition circuit 6 of the fluxgate sensor excites the fluxgate sensor probe 4 and acquires the three components of the magnetic induction intensity at the location, which are B x , B y , B z ;

[0039] (4) As in Figure 2 Among them, the data processing circuit 7 calculates the angles φ1, φ2, and φ3 between the magnetic field vector B (B x , B y , B z ) measured by the fluxgate sensor probe 4 and the optical axis vectors OPM1(x1, y1, z1), OPM2(x2, y2, z2), and OPM3(x3, y3, z3) of the three atomic magnetometer probes 123;

[0040] (5) Compare which of the angles φ1, φ2, and φ3 between the magnetic field vector B and the optical axis is closer to 45°, and select it as the magnetic field output value; according to the principle of the optically pumped magnetometer, when the angle between the optical axis and the magnetic field is 45°, the magnetic resonance effect is the best, and the closer to 45° the magnetic resonance effect is better. Therefore, the magnetic field value is output through the channel where the angle closest to 45° is located, and the effect is the best.

[0041] (6) When the current probe jumps out of the optimal working range and the probe is switched, to ensure the normal execution of the magnetic anomaly detection work, it is necessary to ensure that the magnetic field signal does not jump. The current magnetic field is B n , and the magnetic field at the previous point is B n-1, in order to ensure that the magnetic field does not jump, the value of the magnetic induction intensity after switching is reduced by B n -B n-1 , realizing omnidirectional continuous measurement of the magnetic induction intensity.

[0042] In summary, the above are only the preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An omnidirectional atomic magnetometer with multiple probes, characterized in that It includes a magnetometer sensing unit and a magnetometer excitation acquisition unit, wherein: The magnetometer sensing unit is used to convert the magnetic induction intensity signal into an electrical signal; The magnetometer excitation acquisition unit is used to drive the magnetometer sensing unit to collect signals and perform signal processing.

2. The omnidirectional atomic magnetometer according to claim 1, characterized in that, The magnetometer sensing unit specifically comprises: Three atomic magnetometer probes are used to transmit magnetic fields at any angle and convert magnetic induction intensity signals into photoelectric signals. The optical axes of the three probes form a 45° angle with each other in space. A fluxgate sensor probe is used to measure the three components of the magnetic field. The fluxgate sensor probe is placed in the middle of the three atomic magnetometer probes.

3. The omnidirectional atomic magnetometer according to claim 1, characterized in that, The magnetometer excitation acquisition unit specifically includes: Atomic magnetometer signal excitation acquisition circuit, used to excite the atomic magnetometer to collect magnetic induction intensity signals, and convert analog signals into digital signals through frequency counting to facilitate subsequent data processing; The fluxgate sensor signal excitation acquisition circuit is used to excite the fluxgate sensor to collect the three-component signal of magnetic induction intensity, and to facilitate subsequent data processing through analog-to-digital conversion; The data processing circuit outputs the effective values of the collected multiple magnetic induction intensity signals through an algorithm.

4. A method for measuring magnetic induction intensity applied to the omnidirectional atomic magnetometer according to any one of claims 1-3, characterized in that, The following steps are involved: Step 1: Start the device to preheat; Step 2: Three atomic magnetometer probes and fluxgate sensor probes perform signal acquisition respectively; Step 3: Calculate the angles between the three atomic magnetometer probes and the magnetic field vector through the flux gate; Step 4: The atomic magnetometer probe at the best working angle is determined by the flux gate, and the magnetic field signal collected by the probe is output, and the data signal quality is calculated by the data processing circuit; Step 5: If the data signal quality is OK, the signal is output and displayed; if the data signal quality is problematic, an alarm is issued; Step 6: When the angle between the magnetic field and the magnetometer sensor unit changes, the optimal working angle is recalculated, and the probe is switched without jumps through difference compensation based on the previous data.

5. The magnetic induction intensity measurement method according to claim 4, characterized in that The current probe jumps out of the optimal working range and the probe is switched. To ensure the normal execution of the magnetic anomaly detection work, it is necessary to ensure that the magnetic field signal does not change suddenly. The current magnetic field is B n , the magnetic field at the previous point is B n-1 . To ensure that the magnetic field does not change suddenly, the magnetic induction intensity value after switching is reduced by B n -B n-1 to achieve omni-directional continuous measurement of the magnetic induction intensity.

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