WO2021228065A1 - 一种旋转碟式磁场强探头 - Google Patents

一种旋转碟式磁场强探头 Download PDF

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Publication number
WO2021228065A1
WO2021228065A1 PCT/CN2021/092974 CN2021092974W WO2021228065A1 WO 2021228065 A1 WO2021228065 A1 WO 2021228065A1 CN 2021092974 W CN2021092974 W CN 2021092974W WO 2021228065 A1 WO2021228065 A1 WO 2021228065A1
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magnetic field
axis
magnetic
light
reference signal
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PCT/CN2021/092974
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English (en)
French (fr)
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迪克詹姆斯·G
周志敏
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江苏多维科技有限公司
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Priority to EP21804905.4A priority Critical patent/EP4152027A4/en
Priority to US17/998,631 priority patent/US20240264250A1/en
Priority to JP2022568825A priority patent/JP7445337B2/ja
Publication of WO2021228065A1 publication Critical patent/WO2021228065A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
    • G01R33/06—Measuring direction or magnitude of magnetic fields or magnetic flux using galvano-magnetic devices
    • G01R33/09—Magnetoresistive devices
    • G01R33/098—Magnetoresistive devices comprising tunnel junctions, e.g. tunnel magnetoresistance sensors
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
    • G01R33/0206—Three-component magnetometers
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/0005—Geometrical arrangement of magnetic sensor elements; Apparatus combining different magnetic sensor types
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/0011—Arrangements or instruments for measuring magnetic variables comprising means, e.g. flux concentrators, flux guides, for guiding or concentrating the magnetic flux, e.g. to the magnetic sensor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/0023—Electronic aspects, e.g. circuits for stimulation, evaluation, control; Treating the measured signals; calibration
    • G01R33/0041—Electronic aspects, e.g. circuits for stimulation, evaluation, control; Treating the measured signals; calibration using feed-back or modulation techniques
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/007—Environmental aspects, e.g. temperature variations, radiation, stray fields
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
    • G01R33/06—Measuring direction or magnitude of magnetic fields or magnetic flux using galvano-magnetic devices
    • G01R33/09—Magnetoresistive devices

Definitions

  • the embodiment of the present invention relates to magnetoresistive sensor technology, in particular to a rotating disk type magnetic field strength probe.
  • Magnetoresistive sensors have 1/f noise during normal use. Reducing the noise of magnetoresistive sensors and developing low-noise magnetoresistive sensors are of great significance for improving the accurate measurement of magnetic signals.
  • magnetoresistive sensors have high 1/f noise at low frequencies, but dominated by thermal noise at high frequencies, and their noise energy density is much lower than that at low frequencies. Therefore, at present, it is often selected to pre-modulate the magnetic signal into a high-frequency magnetic field, and then measure it by the magnetoresistive sensor to output a high-frequency voltage signal, and then demodulate it, which can realize the purpose of moving the magnetic signal measurement from the low-frequency area to the high-frequency area. Reduce 1/f noise energy density.
  • the existing high-frequency magnetic signal measuring device greatly increases the complexity and size of the magnetoresistive sensor, and the process complexity also greatly increases.
  • the US patent application with application number US/365,398 discloses a magnetoresistive sensor method and device for modulating the magnetic flux sensed by a magnetic sensor.
  • the application includes at least one magnetic sensor attached to a base structure, a rotating member, And at least one flux concentrator installed on the rotating member. As the rotating member rotates, the at least one magnetic flux concentrator shields the magnetic sensor, thereby modulating the output of the at least one magnetic sensor.
  • This application uses a TMR sensor chip to realize a two-axis sensor, which has a complicated structure and size.
  • the embodiment of the present invention provides a rotating dish type magnetic field strength probe to solve the problem of complicated measurement structure.
  • the embodiment of the present invention provides a rotating dish type magnetic field strength probe, which includes:
  • the cylindrical coordinates of the 4N first soft magnetic sectors are respectively (r[r 1 ,r 2 ], ⁇ [ ⁇ 0 ,90°/N- ⁇ 0 ], z[z 0 ,z 0 +th 1 ] ), (r[r 1 ,r 2 ], ⁇ [ ⁇ 0 +90°/N, 2 ⁇ 90°/N- ⁇ 0 ], z[z 0 ,z 0 +th 1 ]), (r[r 1 ,r 2 ], ⁇ [ ⁇ 0 +(i-1) ⁇ 90°/N,i ⁇ 90°/N- ⁇ 0 ], z[z 0 ,z 0 +th 1 ]) and (r[r 1 ,r 2 ], ⁇ [ ⁇ 0 +(4N-1) ⁇ 90°/N, 4N ⁇ 90°/N- ⁇
  • the non-magnetic wheel rotates around the z-axis at a frequency f
  • the external magnetic field H is modulated by the first soft magnetic sector into sensitive magnetic field components Hx and Hy with a frequency of 4N ⁇ f.
  • the external magnetic field H also
  • the second soft magnetic sector is modulated into a sensitive magnetic field component Hz with a frequency of M ⁇ f.
  • the three sensitive magnetic field components Hx, Hy, and Hz respectively pass through the X-axis, Y-axis, and Z-axis magnetoresistive sensors to output corresponding Measuring signal
  • the reference signal generator outputs a first reference signal with a frequency of 4N ⁇ f and a second reference signal with a frequency of M ⁇ f.
  • the first reference signal, the second reference signal, and the measurement signal are externally
  • the processing circuit demodulates the output magnetic field values Hx, Hy and Hz to measure the high signal-to-noise ratio of the three-dimensional magnetic field signal.
  • the rotating disk-type magnetic field strength probe includes a non-magnetic wheel, 4N first soft magnetic sectors, M second soft magnetic sectors, a reference signal generator, and X-axis, Y-axis, and Z-axis magnetic fields.
  • the resistive sensor, the first soft magnetic sector and the second soft magnetic sector are all located on the non-magnetic wheel, and the X-axis, Y-axis and Z-axis magnetoresistive sensors are located above or below the non-magnetic wheel.
  • the rotating butterfly magnetic field strength probe modulates the static magnetic field into a high-frequency magnetic field and performs measurement in the high-frequency magnetic field.
  • the measurement structure is simple to make, as long as a rotating soft magnetic probe is added to the magnetoresistive sensor, which reduces the complexity and size of the measurement structure.
  • the measurement structure is of value for monitoring the geomagnetic field and improving the signal-to-noise ratio. .
  • FIG. 1 is a schematic diagram of a rotating disk-type magnetic field strength probe provided by an embodiment of the present invention
  • Figure 2 is a sectional view taken along B-B in Figure 1;
  • Figure 3 is a sectional view taken along B-B in Figure 1;
  • Fig. 4 is a schematic diagram of rotation of Fig. 1;
  • Fig. 5a is a diagram of the maximum value position of the induced magnetic field of the Y-axis magnetoresistive sensor
  • Figure 5b is a diagram showing the position of the minimum value of the induced magnetic field of the Y-axis magnetoresistive sensor
  • Fig. 6a is a diagram showing the position of the maximum value of the induced magnetic field of the X-axis magnetoresistive sensor
  • Figure 6b is a diagram of the position of the minimum value of the induced magnetic field of the X-axis magnetoresistive sensor
  • Figure 7a is a diagram of the maximum position of the induced magnetic field of the Z-axis magnetoresistive sensor
  • Fig. 7b is a diagram showing the position of the minimum value of the induced magnetic field of the Z-axis magnetoresistive sensor
  • Fig. 8a is a graph showing the change of the intensity of the X-axis magnetoresistive sensor induced magnetic field with the rotation angle of the non-magnetic runner under the condition of the X-axis unidirectional magnetic field;
  • Fig. 8b is a graph showing the change of the magnetic field intensity of the Z-axis magnetoresistive sensor with the rotation angle of the non-magnetic runner under the condition of the Z-axis unidirectional magnetic field;
  • Figure 9 is a white noise spectrum diagram of a magnetoresistive sensor
  • Figure 10 is a schematic diagram of the structure of an external processing circuit
  • Figure 11 is a schematic diagram of the structure of an external processing circuit
  • Figure 12 is a schematic view of the drive structure of the non-magnetic runner
  • Figure 13 is a schematic diagram of the structure of a magnetic shielding motor.
  • FIG. 1 it is a schematic diagram of a rotating disk magnetic field intensity probe provided by an embodiment of the present invention.
  • FIG. 2 is a cross-sectional view along BB in FIG. 1
  • FIG. 3 is a cross-sectional view along BB in FIG. 1
  • the rotating disk type magnetic field intensity probe 1 includes: a non-magnetic wheel 2, 4N first soft magnetic sectors 3 and M second soft magnetic sectors 4, a first soft magnetic sector 3 and a second soft magnetic sector 4 are all located on the non-magnetic wheel 2, and the cylindrical coordinates of the 4N first soft magnetic sectors 3 are (r[r 1 ,r 2 ], ⁇ [ ⁇ 0 ,90°/N- ⁇ 0 ], z[ z 0 ,z 0 +th 1 ]), (r[r 1 ,r 2 ], ⁇ [ ⁇ 0 +90°/N,2 ⁇ 90°/N- ⁇ 0 ], z[z 0 ,z 0 + th 1 ]), (r[r 1 ,r 2 ], ⁇ [ ⁇ 0 +(i-1) ⁇ 90°/N,i ⁇ 90°/N- ⁇ 0 ], z[z 0 ,z 0 + th 1 ]) and (r[r 1 ,r 2 ], ⁇ [ ⁇ 0 +(
  • the non-magnetic wheel 2 rotates around the z-axis at a frequency f.
  • the external magnetic field H is modulated by the first soft magnetic sector 3 into sensitive magnetic field components Hx and Hy with a frequency of 4N ⁇ f.
  • the external magnetic field H also passes through the second soft magnetic field.
  • the magnetic sector 4 is modulated into a sensitive magnetic field component Hz with a frequency of M ⁇ f.
  • the three sensitive magnetic field components Hx, Hy, and Hz respectively pass through the X-axis, Y-axis, and Z-axis magnetoresistive sensors to output corresponding measurement signals, the reference signal
  • the generator outputs a first reference signal with a frequency of 4N ⁇ f and a second reference signal with M ⁇ f.
  • the first reference signal, the second reference signal and the measurement signal are demodulated by an external processing circuit to output the magnetic field values Hx, Hy and Hz, In this way, the high signal-to-noise ratio of the three-dimensional magnetic field signal is measured.
  • the structure of the non-magnetic runner 2 is circular and has a certain thickness, and a cylindrical substrate with a smaller thickness can be selected.
  • the z coordinate of the device below the lower surface is smaller than z 0
  • the z coordinate of the device located above the upper surface of the non-magnetic wheel 2 is larger than z 0 +th1.
  • the coordinate points of the device in the rotating disk magnetic field probe 1 are characterized by cylindrical coordinates (r, ⁇ , z), where r represents the vertical distance from the z axis, and ⁇ represents the projection of r on the XY plane and the X axis. Angle.
  • the optional non-magnetic wheel 2 can be made of any non-magnetic material such as plastic, ceramic, metal or polymer.
  • the cylindrical coordinates of the eight first soft magnetic sectors 3 are (r[r 1 ,r 2 ], ⁇ [ ⁇ 0 ,45°- ⁇ 0 ], z[z 0 ,z 0 +th 1 ]), (r[r 1 ,r 2 ], ⁇ [ ⁇ 0 +45°,90°- ⁇ 0 ], z[z 0 ,z 0 +th 1 ]), (r[r 1 ,r 2 ], ⁇ [ ⁇ 0 +90°,135°- ⁇ 0 ], z[z 0 ,z 0 +th 1 ]), (r[r 1 ,r 2 ], ⁇ [ ⁇ 0 +135°,180°- ⁇ 0 ] , Z[z 0 ,z 0 +th 1 ]), (r[r 1 ,r 2 ], ⁇ [ ⁇ 0 +180°,225°- ⁇ 0 ], z[z 0 ,z 0 +th 1 ] ), (r[r 1 ,r
  • the cylindrical coordinates of one of the 4N first soft magnetic sectors 3 are (r[r 1 ,r 2 ], ⁇ [ ⁇ 0 ,45°- ⁇ 0 ], z[z 0 , z 0 +th 1 ]), which means that the first soft magnetic sector 3 is located in the non-magnetic wheel shape 2, the upper surface of the first soft magnetic sector 3 coincides with the upper surface of the non-magnetic wheel shape 2, and the first soft magnetic sector The lower surface of the sector 3 coincides with the lower surface of the non-magnetic wheel 2.
  • the thickness of the first soft magnetic sector 3 is equal to the thickness of the non-magnetic wheel 2.
  • the first soft magnetic sector 3 consists of two radius lines and two Surrounded by arcs, where the angle between one radius line and the x axis is ⁇ 0 and the angle between the other radius line and the x axis is 45°- ⁇ 0 , and one arc is located on a circle with a radius of r 2 And the other arc is located on the circle with radius r 1.
  • the included angle between the two radius lines of the first soft magnetic sector 3 is less than 90°.
  • the cylindrical coordinates of the five second soft magnetic sectors 4 are (r[r 3 ,r 4 ], ⁇ [ ⁇ 1 ,72°- ⁇ 1 ], z[z 1 ,z 1 +th 3 ]), (r[r 3 ,r 4 ], ⁇ [ ⁇ 1 +72°,144°- ⁇ 1 ], z[z 1 ,z 1 +th 3 ]), (r[r 3 ,r 4 ], ⁇ [ ⁇ 1 +144°,216°- ⁇ 1 ], z[z 1 ,z 1 +th 3 ]), (r[r 3 ,r 4 ], ⁇ [ ⁇ 1 +216°,288°- ⁇ 1 ] , Z[z 1 ,z 1 +th 3 ]) and (r[r 3 ,r 4 ], ⁇ [ ⁇ 1 +288°, 360°- ⁇ 1 ], z[z 1 ,z 1 +th 3 ] ). It can be understood that both N and M are integers, but 4N/M is not an integer and M/4N is
  • the X-axis, Y-axis and Z-axis magnetoresistive sensors may all be located below the non-magnetic wheel 2.
  • the X-axis, Y-axis, and Z-axis magnetoresistive sensors may all be located above the non-magnetic wheel 2.
  • z 0 and z 1 are all greater than or equal to 0, th 1 , th 2 , th 3 and th 4 are all greater than 0, z 0 and z 1 may be equal or unequal, th 1 , th 2 , th 3 and Any two values in th 4 may be equal or unequal, and are not specifically limited in the present invention. On the basis of not affecting the operation of the rotating disk magnetic field strength probe, relevant practitioners can reasonably set the multiple values.
  • the rotating disk-type magnetic field intensity probe 1 further includes a reference signal generator and a rotating shaft 12, and the optional rotating direction of the rotating shaft 12 is a clockwise direction as shown by the arrow direction in FIG. 4.
  • the rotating shaft 12 rotates at the frequency f to synchronously drive the non-magnetic runner 2 to rotate around the z-axis at the frequency f.
  • the three-dimensional external magnetic field H is modulated by the first soft magnetic sector 3 into sensitive magnetic field components Hx and Hy with a frequency of 4N ⁇ f, and the three-dimensional external magnetic field H is also modulated by the second soft magnetic sector 4 into a sensitive magnetic field with a frequency of M ⁇ f Component Hz.
  • the sensitive magnetic field component Hx is measured by the X-axis magnetoresistive sensors 7 and 8 respectively and the X-axis measurement signal is output.
  • the sensitive magnetic field component Hy is measured by the Y-axis magnetoresistive sensor 5 and 6 respectively and the Y-axis measurement signal is output.
  • the sensitive magnetic field component Hz is Z
  • the axis magnetoresistive sensor 9 measures and outputs a Z axis measurement signal.
  • the reference signal generator outputs a first reference signal with a frequency of 4N ⁇ f and a second reference signal with a frequency of M ⁇ f.
  • the first reference signal, the second reference signal, and the X-axis, Y-axis and Z-axis measurement signals are all output to the external processing circuit, and the external processing circuit demodulates the received reference signal and measurement signal to obtain Hx, Hy and Hz values And output the three magnetic field values, so as to achieve a high signal-to-noise ratio measurement of the magnetic field signal of the three-dimensional external magnetic field H.
  • Figure 5a it is the measurement principle diagram of the Y-axis magnetoresistive sensor.
  • Figure 5a shows the maximum position of the induced magnetic field.
  • the orthographic projection of the Y-axis magnetoresistive sensor 5 on the non-magnetic wheel 2 is located in the gap between the two adjacent first soft magnetic sectors 3(1) and 3(2)
  • the Y-direction induced magnetic field has the largest amplitude, and the span of a single sector is ⁇ .
  • Fig. 5b is the position of the minimum value of the induced magnetic field.
  • the middle position of the soft magnetic sector 3 (2) has the largest magnetic field shielding effect, so the amplitude of the induced magnetic field in the Y direction is the smallest.
  • Figure 6a it is the measurement principle diagram of the X-axis magnetoresistive sensor.
  • Figure 6a shows the maximum position of the induced magnetic field.
  • the orthographic projection of the X-axis magnetoresistive sensor 7 on the non-magnetic wheel 2 is located in the gap between the two adjacent first soft magnetic sectors 3(3) and 3(4)
  • the X-direction induced magnetic field has the largest amplitude, and the span of a single sector is ⁇ .
  • Fig. 6b is the position of the minimum value of the induced magnetic field.
  • the middle position of the soft magnetic sector 3 (3) has the largest magnetic field shielding effect, so the X-direction induced magnetic field amplitude is the smallest.
  • Figure 7a shows the measurement principle diagram of the Z-axis magnetoresistive sensor.
  • Figure 7a shows the maximum position of the induced magnetic field.
  • the orthographic projection of the Z-axis magnetoresistive sensor 9 on the non-magnetic wheel 2 is located directly below or directly above one of the second soft magnetic sectors 4(2), Z The amplitude of the induced magnetic field is the largest, and the span of a single sector is ⁇ 1.
  • Fig. 7b is the position of the minimum value of the induced magnetic field.
  • the orthographic projection of the Z-axis magnetoresistive sensor 9 on the non-magnetic runner 2 is located on two adjacent ones. In the middle of the gap between the second soft magnetic sectors 4(2) and 4(3), the magnetic field shielding effect is the largest, so the Z-direction induced magnetic field amplitude is the smallest.
  • Fig. 8a it is a graph showing the change of the intensity of the magnetic field induced by the X-axis magnetoresistive sensor with the rotation angle of the non-magnetic runner under the condition of the X-axis unidirectional magnetic field. It can be seen that in the range of 0°-360° rotation angle, the X-axis magnetoresistive sensor signal changes periodically and the period is 45°. In this embodiment, there are 8 first soft magnetic sectors 3 in the range of 0°-360°, and the span is 45°. Therefore, assuming that the rotation frequency of the non-magnetic runner is f, the X-axis magnetoresistive sensor frequency is 8* f.
  • FIG. 8b it is a graph showing the change of the magnetic field intensity of the Z-axis magnetoresistive sensor with the rotation angle of the non-magnetic runner under the condition of the Z-axis unidirectional magnetic field. It can be seen that in the range of 0°-360° rotation angle, the Z-axis magnetoresistive sensor signal changes periodically and the period is 72°. In this embodiment, there are 5 second soft magnetic sectors 4 in the range of 0°-360°, with a span of 72°. Therefore, assuming that the rotation frequency of the non-magnetic runner is f, the frequency of the Z-axis magnetoresistive sensor is 5* f.
  • the white noise spectrum of the magnetoresistive sensor Since the white noise has the characteristic of 1/f, that is, the noise of the magnetoresistive sensor is larger when the low frequency is 140, and the noise of the magnetoresistive sensor is greatly reduced when the high frequency is above 150. Therefore, the introduction of a non-magnetic wheel and the 4Nth A soft magnetic sector and M second soft magnetic sectors respectively modulate the measuring magnetic field Hx, Hy and Hz to 4N*f and M*f frequencies, thereby achieving the purpose of reducing white noise and improving signal-to-noise ratio.
  • the rotating disk-type magnetic field strength probe includes a non-magnetic wheel, 4N first soft magnetic sectors, M second soft magnetic sectors, a reference signal generator, and X-axis, Y-axis, and Z-axis magnetic fields.
  • the resistive sensor, the first soft magnetic sector and the second soft magnetic sector are all located on the non-magnetic wheel, and the X-axis, Y-axis and Z-axis magnetoresistive sensors are located above or below the non-magnetic wheel.
  • the non-magnetic wheel rotates around the z-axis at the frequency f.
  • the external magnetic field is modulated by the first soft magnetic sector into sensitive magnetic field components Hx and Hy with a frequency of 4N ⁇ f, and the external magnetic field is also modulated by the second soft magnetic sector.
  • the sensitive magnetic field component Hz with a frequency of M ⁇ f is generated.
  • the three sensitive magnetic field components Hx, Hy and Hz respectively pass through the X-axis, Y-axis and Z-axis magnetoresistive sensors to output corresponding measurement signals.
  • the output frequency of the reference signal generator is The first reference signal of 4N ⁇ f and the second reference signal of M ⁇ f.
  • the first reference signal, the second reference signal and the measurement signal are demodulated by the external processing circuit to output the magnetic field values Hx, Hy and Hz, so as to compare the three-dimensional magnetic field
  • the high signal-to-noise ratio of the signal is measured.
  • the rotating butterfly magnetic field strength probe modulates the static magnetic field into a high-frequency magnetic field and performs measurement in the high-frequency magnetic field. This can effectively overcome the noise caused by the DC drift of the tunnel magnetoresistance (TMR) magnetoresistive sensor and eliminate the DC The influence of offset greatly reduces the noise used by TMR magnetoresistive sensors.
  • TMR tunnel magnetoresistance
  • the measurement structure is simple to make, as long as a rotating soft magnetic probe is added to the magnetoresistive sensor, which reduces the complexity and size of the measurement structure.
  • the measurement structure is of value for monitoring the geomagnetic field and improving the signal-to-noise ratio. .
  • the optional non-magnetic wheel 2 shown in FIGS. 1 to 4 has 4N first light entrance holes 10 and M second light entrance holes 11, and 4N first light entrance holes 10
  • the reference signal generator includes: a first light-emitting element 161, a second light-emitting element 162, a first photodetector 14, a second photodetector 15, a first logic trigger circuit, and a second logic trigger circuit.
  • the first light-emitting element 161 is located At a position above or below the first light entrance hole 10, the second light-emitting element 162 is located above or below the second light entrance hole 11, and the first photodetector 14 is located at the first light entrance hole 10 opposite to the first light-emitting element 161
  • the second light detector 15 is located at the other side of the second light entrance hole 11 opposite to the second light-emitting element 162;
  • the non-magnetic wheel 2 rotates around the z-axis at the frequency f.
  • the first light detection The device 14 triggers the first logic trigger circuit to output a first reference signal with a frequency of 4N ⁇ f and the second photodetector 15 triggers the second logic trigger circuit to output a second reference signal with a frequency of M ⁇ f.
  • the eight first light entrance holes 10 penetrate the upper and lower surfaces of the non-magnetic wheel 2, respectively 10(1) ⁇ 10(8), the first quadrant of the xy coordinate in the original state
  • a first light entrance hole 10 adjacent to the +X axis or a first light entrance hole 10 that overlaps the +X axis is marked as 10(1), and the remaining 7 counterclockwise are marked as 10(2) ⁇ 10( 8) It can be understood that as the non-magnetic wheel 2 rotates, 10(1) will rotate to different positions.
  • a second light entrance hole 11 adjacent to the +X axis or a second light entrance hole 11 that overlaps the +X axis is marked as 11(1), and the remaining 4 counterclockwise are marked as 11(2) ⁇ 11( 5) It can be understood that as the non-magnetic wheel 2 rotates, 11(1) will rotate to different positions.
  • the reference signal generator includes two light-emitting elements and two light-emitting elements, which are respectively a first light-emitting element 161 and a second light-emitting element 162, and a first light-detector 14 and a second light-detector 15 that emit light.
  • the element and the light detector are respectively located on both sides of the non-magnetic wheel 2 so that the light detector can detect the light emitted by the light-emitting element through the light entrance hole.
  • the optional light detector and magnetoresistive sensor are located on the same side of the non-magnetic wheel 2.
  • the optional first light-emitting element 161 is located above the first light entrance hole 10, the second light-emitting element 162 is located above the second light entrance hole 11, and the first light detector 14 is located at the first light entrance hole. At a position below the hole 10, the second light detector 15 is located at a position below the second light entrance hole 11. In other embodiments, as shown in FIG. 3, the first light emitting element 161 may be located at a position below the first light entrance hole 10, and the second light emitting element 162 may be located at a position below the second light entrance hole 11. The detector 14 is located above the first light entrance hole 10, and the second light detector 15 is located above the second light entrance hole 11.
  • the optional light-emitting element is an LED lamp or any other suitable light-emitting element. It can be understood that the positions of the light-emitting element and the photodetector are fixed after being determined.
  • the rotating shaft 12 rotates at the frequency f to synchronously drive the non-magnetic runner 2 to rotate around the z-axis at the frequency f, and the position of the light entrance hole on the non-magnetic runner 2 rotates.
  • the first light detector 14 located below the first light entrance hole 10 can detect The light emitted by the first light-emitting element 161, the first photodetector 14 triggers the first logic trigger circuit to output a first reference signal with a frequency of 4N ⁇ f, and the second photodetector 15 located below the second light entrance hole 11 can detect When the light emitted by the second light-emitting element 162 is reached, the second photodetector 15 triggers the second logic trigger circuit to output a second reference signal with a frequency of M ⁇ f.
  • Optional first reference signal and second reference signal are both high-level or low-level signals; before the first light detector detects the light emitted by the first light-emitting element, the level of the first logic trigger circuit remains unchanged After the first light detector detects the light emitted by the first light-emitting element, the level of the first logic trigger circuit is switched; before the second light detector detects the light emitted by the second light-emitting element, the second logic triggers The level of the circuit remains unchanged. After the second photodetector detects the light emitted by the second light-emitting element, the level of the second logic trigger circuit changes.
  • the first light detector 14 can detect the light-emitting element 151.
  • the light triggers the first logic trigger circuit, the first logic trigger circuit switches the output level of the first reference signal; if the non-magnetic wheel 2 rotates to the first light-emitting element 161, the first light entrance hole 10 and the first light detection
  • the first photodetector 14 cannot detect the light of the first light-emitting element 161
  • the first logic trigger circuit keeps the level of the first reference signal unchanged.
  • the switching process of the second reference signal is completely the same as the switching process of the first reference signal, and will not be repeated here.
  • the non-magnetic wheel 2 rotates around the z-axis at a frequency f, and the position of the light entrance hole changes.
  • the first photodetector 14 detects the light of the first light-emitting element 161 and converts the light signal into an electrical signal, thereby being able to detect non-magnetic
  • the angular displacement of the runner 2 triggers the first logic trigger circuit to output a first reference signal with a frequency of 4N ⁇ f.
  • the level of the first reference signal can be selected to be high and the output is maintained;
  • the first photodetector 14 detects the light of the first light-emitting element 161 and converts the light signal into an electrical signal, thereby being able to detect the non-magnetic wheel Angular displacement of 2 and trigger the first logic trigger circuit to switch the level of the first reference signal.
  • the first reference signal is switched from a high level to a low level with a frequency of 4N ⁇ f, and the output is maintained; and so on,
  • the first photodetector 14 triggers the first logic trigger circuit to switch the level of the first reference signal.
  • the first logic trigger circuit When the first light entrance hole 10 and the first light emitting element 161 During interleaving, the level of the first reference signal output by the first logic trigger circuit remains unchanged. It can be seen that the first logic trigger circuit outputs a first reference signal composed of a high level and a low level with a frequency of 4N ⁇ f.
  • the second logic trigger circuit outputs a second reference signal composed of a high level and a low level with a frequency of M ⁇ f.
  • the first photodetector 14, the second photodetector 15, the X-axis magnetoresistive sensors 7 and 8, the Y-axis magnetoresistive sensors 5 and 6, and the Z-axis magnetoresistive sensor 9 are located on the same circuit board 13. It can be understood that the photodetector, magnetoresistive sensor, logic trigger circuit and other structures are all located on the same circuit board 13, and the logic trigger circuit is electrically connected to the corresponding photodetector, but the cylindrical coordinates of the logic trigger circuit are not specifically limited.
  • the optional reference signal generator includes an analog angle sensor and a frequency multiplier; the analog angle sensor monitors the rotation of the non-magnetic runner, and outputs a sine or cosine periodic signal that changes with the angle, Then, the first reference signal with the frequency of 4N ⁇ f and the second reference signal with the frequency of M ⁇ f are respectively output through the frequency multiplier.
  • the reference signal generator in this embodiment can be arranged on the rotating shaft.
  • the reference signal generator includes an analog angle sensor, which can be used to detect the rotation of the rotating shaft, and output a sine or cosine signal with a frequency of f according to the rotation angle of the rotating shaft.
  • the reference signal generator also includes a frequency multiplier.
  • the sine or cosine signal with frequency f is passed through the frequency multiplier to generate a first reference signal with a frequency of 4N ⁇ f and a second reference signal with a frequency of M ⁇ f, respectively.
  • the optional X-axis magnetoresistive sensor, Y-axis magnetoresistive sensor, and Z-axis magnetoresistive sensor are all tunnel magnetoresistive linear sensors.
  • the optional external processing circuit includes a first phase-locked circuit 24, a second phase-locked circuit 28, and a third phase-locked circuit 26; the measurement signals of the Y-axis magnetoresistive sensors 5 and 6 are coupled and output through the first capacitor 20 To the first phase lock circuit 24, the measurement signals of the X-axis magnetoresistive sensors 7 and 8 are coupled and output to the second phase lock circuit 28 through the second capacitor 22, and the measurement signals of the Z-axis magnetoresistive sensor 9 are coupled and output through the third capacitor 21.
  • the cut-off frequencies of the low-pass filters of the first phase-locked circuit 24 and the second phase-locked circuit 28 are both less than 4N ⁇ f ,
  • the cut-off frequency of the low-pass filter of the third phase lock circuit 26 is less than M ⁇ f.
  • the optional external processing circuit also includes a preamplifier, which is arranged between the capacitor and the phase lock circuit.
  • the physical quantity to be measured 43 that is, the measurement signal
  • the sensor 44 is modulated by the sensor 44 to form a signal with a frequency f, which includes a high-frequency carrier signal source Vac and a corresponding sensor 441.
  • the phase-locked circuit 42 can be selected as a phase-locked amplifier or a phase-locked loop, including a mixer 421 and a low-pass filter 422.
  • the modulation signal output by the modulation sensor 44 is amplified by a noise amplifier 45 to obtain a signal frequency of f Signal, among them, the noise amplifier 45 is the pre-amplifier.
  • the high-frequency carrier signal source Vac directly outputs a reference signal of the same frequency with a signal of frequency f.
  • the reference signal is input to the mixer 421. After mixing, a high-frequency signal and a low-frequency signal are obtained, and then low-pass filtering is performed.
  • the converter 422 removes the low frequency part. Since the noise signal does not undergo frequency shift, the noise of the amplifier 45 is also filtered out, and finally a high-frequency output signal 46 without amplifier noise is obtained.
  • the optional first reference signal is respectively connected to the first phase lock circuit 24 and the second phase lock circuit 28.
  • the first phase lock circuit 24 outputs a Vy signal corresponding to the Y-axis magnetic field component of the external magnetic field H.
  • the second phase lock circuit 28 outputs the Vx signal corresponding to the X-axis magnetic field component of the external magnetic field H; the second reference signal is connected to the third phase lock circuit 26, and the third phase lock circuit 26 outputs the Z-axis magnetic field component corresponding to the external magnetic field H
  • the Vz signal is the lock-in amplifier shown in the figure.
  • the first light entrance hole 10(1) is illuminated by the first light-emitting element 161, and the first photodetector 14 converts the frequency f of the rotation of the non-magnetic wheel 2 into a first reference signal of 4N ⁇ f.
  • the second light entrance hole 11(1) is illuminated by the second light-emitting element 162, and the second photodetector 15 converts the frequency f of the rotation of the non-magnetic wheel 2 into a second reference signal of M ⁇ f.
  • the first reference signal is respectively transmitted to the trigger 23 and the trigger 27, and is input to the reference signal input terminal of the lock-in amplifier 24 through the trigger 23, and is used to subsequently obtain the measurement signal of the corresponding Y-axis magnetoresistive sensor.
  • the second reference signal is transmitted to the trigger 25, and input to the reference signal input terminal of the lock-in amplifier 26 via the trigger 25, and is used to subsequently obtain the measurement signal corresponding to the Z-axis magnetoresistive sensor.
  • the sensitive magnetic field components Hx, Hy and Hz received by the X-axis magnetoresistive sensor 7, Y-axis magnetoresistive sensor 5, and Z-axis magnetoresistive sensor 9 are converted into frequencies of 4N ⁇ f, 4N ⁇ f and M ⁇ , respectively.
  • the electrical signal of f is input to the measurement signal input terminals of the lock-in amplifiers 24, 26, and 28 after passing through the coupling capacitors, namely, the first capacitor 20, the second capacitor 22, and the third capacitor 21, respectively.
  • the lock-in amplifier 24 obtains the output signal Vy of the Y-axis magnetic field component according to the first reference signal output by the trigger 23 and the Y-axis measurement signal of the Y-axis magnetoresistive sensor 5;
  • the reference signal and the X-axis measurement signal of the X-axis magnetoresistive sensor 7 are obtained to obtain the output signal Vx of the X-axis magnetic field component.
  • the lock-in amplifier 26 is based on the second reference signal output by the trigger 25 and the Z-axis measurement signal of the Z-axis magnetoresistive sensor. , Get the output signal of the Z-axis magnetic field component, and finally get the vector value of the external magnetic field.
  • the reference signals corresponding to the lock-in amplifiers 24, 26, and 28 are in the form of pulses, and the light signals received by the photodetectors 14 and 15 are used to excite the triggers 23, 25, and 27, and then output high level and low level respectively.
  • Each time the photodetector receives the incident light from the LED it will trigger the high and low level reversal, that is, the low level at the beginning, and keep the low level until it receives the incident light from the LED, and switch to high after receiving the incident light from the LED. Level, and keeps the high level, until receiving the next LED incident light, from the high level to the low level again.
  • the optional non-magnetic runner 2 is driven to rotate by a magnetic shielding motor 29, and the non-magnetic runner 2 and the magnetic shielding motor 29 are driven by a non-magnetic transmission.
  • the shaft 12 is connected, the surface of the magnetic shielding motor 29 is covered with a metal conductive layer 291, and the side of the magnetic shielding motor 291 close to the non-magnetic runner 2 is covered with a soft magnetic metal layer 292 for magnetic shielding.
  • the first soft magnetic sector 3, the second soft magnetic sector 4, and the soft magnetic metal layer 292 are all soft magnetic alloy materials.
  • the magnetic shielding motor 29 drives the non-magnetic runner 2 to rotate through the non-magnetic transmission shaft, that is, the rotating shaft 12.
  • the magnetic shielding motor 29 includes a motor 293 and a rotating shaft 12 connecting the motor 293 and the non-magnetic runner 2, and also includes a metal conductive shielding layer 291 wrapped on the surface of the motor 293.
  • the side close to the non-magnetic runner 2 is also attached with a soft Magnetic metal layer 292.
  • the non-magnetic runner 2 is made of non-magnetic materials, including plastics, ceramics, metals and polymers; the first soft magnetic sector, the second soft magnetic sector and the soft magnetic metal layer are made of soft magnetic alloy materials, that is, containing Co, Fe, High permeability soft magnetic material composed of Ni, B, Si, C and transition metals Nb, Cu, Zr.
  • the soft magnetic metal shielding layer 292 is used to shield the rotating magnetic field of the motor 293 so as not to affect the non-magnetic runner 2.

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Abstract

一种旋转碟式磁场强探头（1），包括：非磁性转轮（2）、4N个第一软磁扇区（3）、M个第二软磁扇区（4）、参考信号发生器以及X轴磁阻传感器（7，8）、Y轴磁阻传感器（5，6）、Z轴磁阻传感器（9），第一软磁扇区（3）、第二软磁扇区（4）均位于非磁性转轮（2）上；工作时，非磁性转轮（2）以频率f绕z轴旋转，外磁场经第一软磁扇区（3）调制成频率为4N×f的x轴敏感磁场分量和y轴敏感磁场分量，还经第二软磁扇区调制成频率为M×f的z轴敏感磁场分量，x轴敏感磁场分量、y轴敏感磁场分量和z轴敏感磁场分量分别经过X轴磁阻传感器（7，8）、Y轴磁阻传感器（5，6）、Z轴磁阻传感器（9）输出对应的测量信号，参考信号发生器输出频率为4N×f的第一参考信号和M×f的第二参考信号，第一参考信号、第二参考信号和测量信号经外部处理电路解调输出磁场值Hx、Hy和Hz。

Description

一种旋转碟式磁场强探头 技术领域
本发明实施例涉及磁阻传感器技术，尤其涉及一种旋转碟式磁场强探头。
背景技术
磁电阻传感器在正常使用时存在着1/f噪声，降低磁电阻传感器的噪声以及发展低噪声磁电阻传感器对于提高磁信号的精确测量具有重要的意义。
一般情况下，磁电阻传感器在低频时具有高的1/f噪声，而在高频时则以热噪声为主，其噪声能量密度大大低于低频时的噪声能量密度。因此，目前多选择将磁信号预先调制成高频磁场，再被磁电阻传感器测量以输出高频电压信号，而后进行解调，可以实现将磁信号测量从低频区域移动到高频区域的目的，降低1/f噪声能量密度。
然而，现有高频磁信号测量装置使得磁电阻传感器的复杂程度和尺寸大为增加，工艺复杂程度也大为增加。
申请号为US/365,398的美国专利申请公开了一种磁阻传感器方法和装置，用于调制磁传感器感测的磁通，该申请包括至少一个附接至基座结构的磁传感器、旋转构件，以及至少一个安装在旋转构件上的通量集中器，随着旋转构件的旋转，至少一个磁通集中器屏蔽了磁传感器，从而调制了至少一个磁传感器的输出。该申请使用一个TMR传感器芯片实现两轴传感器，其结构尺寸复杂。
发明内容
本发明实施例提供一种旋转碟式磁场强探头，以解决测量结构复杂的问题。
本发明实施例提供了一种旋转碟式磁场强探头，包括：
非磁性转轮、4N个第一软磁扇区和M个第二软磁扇区，所述第一软磁扇区和所述第二软磁扇区均位于所述非磁性转轮上，所述4N个第一软磁扇区的柱坐标分别为(r[r 1,r 2]，α[Φ 0,90°/N-Φ 0]，z[z 0,z 0+th 1])、(r[r 1,r 2]，α[Φ 0+90°/N，2×90°/N-Φ 0]，z[z 0,z 0+th 1])、(r[r 1,r 2]，α[Φ 0+(i-1)×90°/N,i×90°/N-Φ 0]，z[z 0,z 0+th 1])和(r[r 1,r 2]，α[Φ 0+(4N-1)×90°/N,4N×90°/N-Φ 0]，z[z 0,z 0+th 1])，所述M个第二软磁扇区的柱坐标分别为(r[r 3,r 4]，α[Φ 1,360°/M-Φ 1]，z[z 1,z 1+th 3])、 (r[r 3,r 4]，α[Φ 1+360°/M,2×360°/M-Φ 1]，z[z 1,z 1+th 3])、(r[r 3,r 4]，α[Φ 1+(i-1)×360°/M，i×360°/M-Φ 1]，z[z 1,z 1+th 3])和(r[r 3,r 4]，α[Φ 1+(M-1)×360°/M,M×360°/M-Φ 1]，z[z 1,z 1+th 3])；
位于柱坐标(r(r＝(r 1+r 2)/2)，α(α＝0°&180°)，z[(z＝z 0-th 2)|(z＝z 0+th 1+th 2)])位置处的Y轴磁阻传感器；
位于柱坐标(r(r＝(r 1+r 2)/2)，α(α＝90°&270°)，z[(z＝z 0-th 2)|(z＝z 0+th 1+th 2)])位置处的X轴磁阻传感器；
位于柱坐标(r(r＝(r 3+r 4)/2),α[(α＝180°/M)|(α＝3×180°/M)|…|(α＝(2i-1)×180°/M)|…|(α＝(2M-1)×360°/M)|(α＝(M-1)×360°/M)]，z[(z＝z 1-th 4)|(z＝z 1+th 3+th 4)])位置处的Z轴磁阻传感器；
以及参考信号发生器，其中4N/M和M/4N均为非整数；
工作时，所述非磁性转轮以频率f绕z轴旋转，外磁场H经所述第一软磁扇区调制成频率为4N×f的敏感磁场分量Hx和Hy，所述外磁场H还经所述第二软磁扇区调制成频率为M×f的敏感磁场分量Hz，该三个敏感磁场分量Hx、Hy和Hz分别经过该X轴、Y轴和Z轴磁阻传感器输出对应的测量信号，所述参考信号发生器输出频率为4N×f的第一参考信号和M×f的第二参考信号，所述第一参考信号、所述第二参考信号和所述测量信号经外部处理电路解调输出磁场值Hx、Hy和Hz，以此对三维磁场信号的高信噪比进行测量。
本发明实施例中，旋转碟式磁场强探头包括非磁性转轮、4N个第一软磁扇区、M个第二软磁扇区、参考信号发生器以及X轴、Y轴和Z轴磁阻传感器，第一软磁扇区和第二软磁扇区均位于非磁性转轮上，X轴、Y轴和Z轴磁阻传感器位于非磁性转轮的上方或下方位置处。本发明实施例中，旋转蝶式磁场强探头将静止磁场调制成高频磁场，在高频磁场中进行测量，这样可以有效克服TMR磁阻传感器直流漂移引起的噪声，消除直流offset的影响，大大降低TMR磁阻传感器使用的噪声。并且该测量结构制作方法简单，只要在磁阻传感器外加一个旋转软磁探头即可实现，降低了测量结构的复杂性和尺寸，该测量结构对于地磁场的监控及信噪比的提高具有使用价值。
附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图做一简单地介绍，显而易见地，下面描述中的附图虽然是本发明的一些具体的实施例，对于本领域的技术人员来说，可以根据本发明的各种实施例所揭示和提示的器件结构，驱动方法和制造方法的基本概念，拓展和延伸到其它的结构和附图， 毋庸置疑这些都应该是在本发明的权利要求范围之内。
图1是本发明实施例提供的一种旋转碟式磁场强探头的示意图；
图2是图1沿B-B的剖视图；
图3是图1沿B-B的剖视图；
图4是图1的旋转示意图；
图5a是Y轴磁阻传感器的感应磁场极大值位置图；
图5b是Y轴磁阻传感器的感应磁场极小值位置图；
图6a是X轴磁阻传感器的感应磁场极大值位置图；
图6b是X轴磁阻传感器的感应磁场极小值位置图；
图7a是Z轴磁阻传感器的感应磁场极大值位置图；
图7b是Z轴磁阻传感器的感应磁场极小值位置图；
图8a是X轴单向磁场条件下X轴磁阻传感器感应磁场强度随非磁性转轮旋转角度的变化图；
图8b是Z轴单向磁场条件下Z轴磁阻传感器感应磁场强度随非磁性转轮旋转角度的变化图；
图9是磁阻传感器的白噪声频谱图；
图10是外部处理电路的结构示意图；
图11是外部处理电路的结构示意图；
图12是非磁性转轮的驱动结构示意图；
图13是磁屏蔽电机的结构示意图。
具体实施方式
为使本发明的目的、技术方案和优点更加清楚，以下将参照本发明实施例中的附图，通过实施方式清楚、完整地描述本发明的技术方案，显然，所描述的实施例是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例所揭示和提示的基本概念，本领域的技术人员所获得的所有其他实施例，都属于本发明保护的范围。
参考图1所示，为本发明实施例提供的一种旋转碟式磁场强探头的示意图，图2是图1沿B-B的剖视图，图3是图1沿B-B的剖视图，图4是图1的旋转示意图。该旋转碟式磁场强探头1包括：非磁性转轮2、4N个第一软磁扇区3和M个第二软磁扇区4，第一软磁扇区3和第二软磁扇区4均位于非磁性转轮2上，4N个第一软磁扇区3的柱坐标分别为 (r[r 1,r 2]，α[Φ 0,90°/N-Φ 0]，z[z 0,z 0+th 1])、(r[r 1,r 2]，α[Φ 0+90°/N,2×90°/N-Φ 0]，z[z 0,z 0+th 1])、(r[r 1,r 2]，α[Φ 0+(i-1)×90°/N,i×90°/N-Φ 0]，z[z 0,z 0+th 1])和(r[r 1,r 2]，α[Φ 0+(4N-1)×90°/N,4N×90°/N-Φ 0]，z[z 0,z 0+th 1])，M个第二软磁扇区4的柱坐标分别为(r[r 3,r 4]，α[Φ 1,360°/M-Φ 1]，z[z 1,z 1+th 3])、(r[r 3,r 4]，α[Φ 1+360°/M,2×360°/M-Φ 1]，z[z 1,z 1+th 3])、(r[r 3,r 4]，α[Φ 1+(i-1)×360°/M，i×360°/M-Φ 1]，z[z 1,z 1+th 3])和(r[r 3,r 4]，α[Φ 1+(M-1)×360°/M,M×360°/M-Φ 1]，z[z 1,z 1+th 3])；位于柱坐标(r(r＝(r 1+r 2)/2)，α(α＝0°&180°)，z[(z＝z 0-th 2)|(z＝z 0+th 1+th 2)])位置处的Y轴磁阻传感器5和6；位于柱坐标(r(r＝(r 1+r 2)/2)，α(α＝90°&270°)，z[(z＝z 0-th 2)|(z＝z 0+th 1+th 2)])位置处的X轴磁阻传感器7和8；位于柱坐标(r(r＝(r 3+r 4)/2),α[(α＝180°/M)|(α＝3×180°/M)|…|(α＝(2i-1)×180°/M)|…|(α＝(2M-1)×360°/M)|(α＝(M-1)×360°/M)],z[(z＝z 1-th 4)|(z＝z 1+th 3+th 4)])位置处的Z轴磁阻传感器9；以及参考信号发生器，其中4N/M和M/4N均为非整数；
工作时，非磁性转轮2以频率f绕z轴旋转，外磁场H经第一软磁扇区3调制成频率为4N×f的敏感磁场分量Hx和Hy，外磁场H还经第二软磁扇区4调制成频率为M×f的敏感磁场分量Hz，该三个敏感磁场分量Hx、Hy和Hz分别经过该X轴、Y轴和Z轴磁阻传感器输出对应的测量信号，参考信号发生器输出频率为4N×f的第一参考信号和M×f的第二参考信号，第一参考信号、第二参考信号和测量信号经外部处理电路解调输出磁场值Hx、Hy和Hz，以此对三维磁场信号的高信噪比进行测量。
本实施例中，非磁性转轮2的结构形状为圆形且具有一定厚度，可选为厚度较小的圆柱体衬底。以非磁性轮状2的中心轴为z＝0轴建立xyz坐标系，其中，X轴和Y轴构成的平面平行于非磁性轮状2的上下表面，Z轴方向垂直于非磁性轮状2的表面即平行于非磁性轮状2的厚度方向。可选非磁性轮状2的下表面的z坐标为z＝z 0，非磁性转轮2的厚度为th1，则其上表面的z坐标为z＝z 0+th1，位于非磁性轮状2下表面下方的器件的z坐标小于z 0，位于非磁性轮状2上表面上方的器件的z坐标大于z 0+th1。该旋转碟式磁场强探头1中器件的坐标点采用柱坐标(r，α，z)进行表征，其中，r表征与z轴的垂直间距，α表征为r在X-Y平面的投影与X轴的夹角。可选非磁性轮状2的材质为塑料、陶瓷、金属或聚合物等任意一种非磁性材料。
本实施例中，4N个第一软磁扇区3位于非磁性转轮2上。假设N＝2，则如图1所示非磁性转轮2上具有8个第一软磁扇区3，分别为3(1)～3(8)，原始状态下xy坐标第一象限内紧邻+X轴的一第一软磁扇区3标记为3(1)，剩余7个逆时针依次标记为3(2)～3(8)，可以理解，随着非磁性转轮2的旋转，3(1)会旋转至不同位置。该8个第一软磁扇区3的柱坐标分别为(r[r 1,r 2]，α[Φ 0,45°-Φ 0]，z[z 0,z 0+th 1])，(r[r 1,r 2]，α[Φ 0+45°,90°-Φ 0]，z[z 0,z 0+th 1])，(r[r 1,r 2]， α[Φ 0+90°,135°-Φ 0]，z[z 0,z 0+th 1])，(r[r 1,r 2]，α[Φ 0+135°,180°-Φ 0]，z[z 0,z 0+th 1])，(r[r 1,r 2]，α[Φ 0+180°,225°-Φ 0]，z[z 0,z 0+th 1])，(r[r 1,r 2]，α[Φ 0+225°,270°-Φ 0]，z[z 0,z 0+th 1])，(r[r 1,r 2]，α[Φ 0+270°，315°-Φ 0]，z[z 0,z 0+th 1])和(r[r 1,r 2]，α[Φ 0+315°,360°-Φ 0]，z[z 0,z 0+th 1])。可以理解，在其他实施例中还可选N＝1或N为大于或等于3的正整数。
4N个第一软磁扇区3的其中一个第一软磁扇区3的柱坐标为(r[r 1,r 2]，α[Φ 0,45°-Φ 0]，z[z 0,z 0+th 1])，表征该第一软磁扇区3位于非磁性轮状2内，第一软磁扇区3的上表面与非磁性轮状2的上表面重合，第一软磁扇区3的下表面与非磁性轮状2的下表面重合，该第一软磁扇区3的厚度等于非磁性轮状2的厚度，第一软磁扇区3由两条半径线和两条圆弧所围成，其中，一条半径线与x轴的夹角为Φ 0且另一条半径线与x轴的夹角为45°-Φ 0，一条圆弧位于半径为r 2的圆上且另一条圆弧位于半径为r 1的圆上。可选第一软磁扇区3的两条半径线的夹角小于90°。
本实施例中，M个第二软磁扇区4位于非磁性转轮2上。假设M＝5，则如图1所示非磁性转轮2上具有5个第二软磁扇区4，分别为4(1)～4(5)，原始状态下xy坐标第一象限内紧邻+X轴的一第二软磁扇区4标记为4(1)，剩余4个逆时针依次标记为4(2)～4(5)，可以理解，随着非磁性转轮2的旋转，4(1)会旋转至不同位置。该5个第二软磁扇区4的柱坐标分别为(r[r 3,r 4]，α[Φ 1,72°-Φ 1]，z[z 1,z 1+th 3])，(r[r 3,r 4]，α[Φ 1+72°,144°-Φ 1]，z[z 1,z 1+th 3])，(r[r 3,r 4]，α[Φ 1+144°,216°-Φ 1]，z[z 1,z 1+th 3])，(r[r 3,r 4]，α[Φ 1+216°,288°-Φ 1]，z[z 1,z 1+th 3])和(r[r 3,r 4]，α[Φ 1+288°，360°-Φ 1]，z[z 1,z 1+th 3])。可以理解，N和M均为整数，但4N/M不是整数以及M/4N不是整数，则在其他实施例中还可选M＝3，或者N确定后可以合理选取一个正整数M。
可选该旋转碟式磁场强探头1还包括两个X轴磁阻传感器7和8，两个Y轴磁阻传感器5和6以及一个Z轴磁阻传感器9，可选Y轴磁阻传感器5位于α＝0°位置处，Y轴磁阻传感器6位于α＝180°位置处，X轴磁阻传感器7位于α＝90°位置处，X轴磁阻传感器8位于α＝270°位置处。
本实施例中，可选该X轴、Y轴和Z轴磁阻传感器均位于非磁性转轮2的下方。其中，Y轴磁阻传感器5的柱坐标为(r(r＝(r 1+r 2)/2)，α(α＝0°)，z(z＝z 0-th 2))，Y轴磁阻传感器6的柱坐标为(r(r＝(r 1+r 2)/2)，α(α＝180°)，z(z＝z 0-th 2))，X轴磁阻传感器7的柱坐标为(r(r＝(r 1+r 2)/2)，α(α＝90°)，z(z＝z 0-th 2))，X轴磁阻传感器8的柱坐标为(r(r＝(r 1+r 2)/2)，α(α＝270°)，z(z＝z 0-th 2))，Z轴磁阻传感器9的柱坐标为(r(r＝(r 3+r 4)/2),α(α＝180°/M),z(z＝z 1-th 4))。
在其他实施例中，如图3所示还可选该X轴、Y轴和Z轴磁阻传感器均位于非磁性转 轮2的上方。其中，Y轴磁阻传感器5的柱坐标为(r(r＝(r 1+r 2)/2)，α(α＝0°)，z(z＝z 0+th 1+th 2))，Y轴磁阻传感器6的柱坐标为(r(r＝(r 1+r 2)/2)，α(α＝180°)，z(z＝z 0+th 1+th 2))，X轴磁阻传感器7的柱坐标为(r(r＝(r 1+r 2)/2)，α(α＝90°)，z(z＝z 0+th 1+th 2))，X轴磁阻传感器8的柱坐标为(r(r＝(r 1+r 2)/2)，α(α＝270°)，z(z＝z 0+th 1+th 2))，Z轴磁阻传感器9的柱坐标为(r(r＝(r 3+r 4)/2),α(α＝180°/M),z(z＝z 1-th 4))。
在其他实施例中，还可选Z轴磁阻传感器的柱坐标为(r(r＝(r 3+r 4)/2),α(α＝3×180°/M),z(z＝z 1-th 4))，或为(r(r＝(r 3+r 4)/2),α(α＝5×180°/M)，z(z＝z 1-th 4))，或为(r(r＝(r 3+r 4)/2),α(α＝7×180°/M),z(z＝z 1-th 4))，或为(r(r＝(r 3+r 4)/2)，α(α＝9×180°/M),z(z＝z 1-th 4))。
可以理解，z 0和z 1均大于或等于0，th 1、th 2、th 3和th 4均大于0，z 0和z 1可以相等也可以不等，th 1、th 2、th 3和th 4中任意两个数值可以相等也可以不等，在本发明中不进行具体限定，在不影响旋转碟式磁场强探头工作的基础上，相关从业人员可以合理设置该多项数值。
本实施例中，该旋转碟式磁场强探头1还包括参考信号发生器和转轴12，可选转轴12的旋转方向为图4箭头方向所示的顺时针方向。
工作时，转轴12以频率f旋转同步带动非磁性转轮2以频率f绕z轴旋转。三维外磁场H经第一软磁扇区3调制成频率为4N×f的敏感磁场分量Hx和Hy，三维外磁场H还经第二软磁扇区4调制成频率为M×f的敏感磁场分量Hz。敏感磁场分量Hx分别被X轴磁阻传感器7和8测量并输出X轴测量信号，敏感磁场分量Hy分别被Y轴磁阻传感器5和6测量并输出Y轴测量信号，敏感磁场分量Hz被Z轴磁阻传感器9测量并输出Z轴测量信号。参考信号发生器输出频率为4N×f的第一参考信号和M×f的第二参考信号。第一参考信号、第二参考信号以及X轴、Y轴和Z轴测量信号均输出至外部处理电路，外部处理电路对接收的参考信号和测量信号进行解调后得出Hx、Hy和Hz值并输出该三个磁场值，以此实现对三维外磁场H的磁场信号的高信噪比测量。
如图5a和图5b所示，为Y轴磁阻传感器的测量原理图。图5a为感应磁场极大值位置，此时Y轴磁阻传感器5在非磁性转轮2上的正投影位于相邻两个第一软磁扇区3(1)和3(2)的间隙中间，Y向感应磁场幅度最大，单个扇区跨越弧度为Φ。图5b为感应磁场极小值位置，此时第一软磁扇区3(2)的旋转角度θ＝Φ/2，Y轴磁阻传感器5在非磁性转轮2上的正投影位于第一软磁扇区3(2)的正中间位置，磁场屏蔽效果最大，因此Y向感应磁场幅度最小。
如图6a和图6b所示，为X轴磁阻传感器的测量原理图。图6a为感应磁场极大值位置，此时X轴磁阻传感器7在非磁性转轮2上的正投影位于相邻两个第一软磁扇区3(3)和3(4)的间隙中间，X向感应磁场幅度最大，单个扇区跨越弧度为Φ。图6b为感应磁场极小值位置，此时第一软磁扇区3(3)的旋转角度θ＝Φ/2，X轴磁阻传感器7在非磁性转轮2上的正投影位于第一软磁扇区3(3)的正中间位置，磁场屏蔽效果最大，因此X向感应磁场幅度最小。
如图7a和图7b所示，为Z轴磁阻传感器的测量原理图。图7a为感应磁场极大值位置，此时Z轴磁阻传感器9在非磁性转轮2上的正投影位于其中一个第二软磁扇区4(2)的正下方或者正上方位置，Z向感应磁场幅度最大，单个扇区跨越弧度为Φ1。图7b为感应磁场极小值位置，此时第二磁性扇区4(2)的旋转角度θ1＝Φ1/2，Z轴磁阻传感器9在非磁性转轮2上的正投影位于相邻两个第二软磁扇区4(2)和4(3)的间隙中间，磁场屏蔽效果最大，因此Z向感应磁场幅度最小。
如图8a所示，为X轴单向磁场条件下X轴磁阻传感器感应磁场强度随非磁性转轮旋转角度的变化图。可以看出，在0°-360°旋转角度范围内，X轴磁阻传感器信号为周期变化且周期为45°。本实施例中选择在0°-360°范围内有8个第一软磁扇区3，跨度为45°，因此假设非磁性转轮旋转频率为f，则X轴磁阻传感器频率为8*f。
同时可以看出，在Y轴单向磁场条件下，Y轴磁阻传感器感应磁场强度随非磁性转轮角度的变化，和X轴单向磁场条件下X轴磁阻传感器磁场强度随非磁性转轮旋转角度的变化是一致的，其结果和图8a相似。
如图8b所示，为Z轴单向磁场条件下Z轴磁阻传感器感应磁场强度随非磁性转轮旋转角度的变化图。可以看出，在0°-360°旋转角度范围内，Z轴磁阻传感器信号为周期变化且周期为72°。本实施例中选择在0°-360°范围内有5个第二软磁扇区4，跨度为72°，因此假设非磁性转轮旋转频率为f，则Z轴磁阻传感器频率为5*f。
如图9所示，为磁阻传感器的白噪声频谱图。由于白噪声具有1/f特征，即在低频140时磁阻传感器噪声较大，而在高频150以上时磁阻传感器噪声大幅降低，因此通过引入非磁性转轮以及在其上设置4N个第一软磁扇区和M个第二软磁扇区，分别将测量磁场Hx、Hy和Hz调制到4N*f和M*f频率，从而达到降低白噪声和提高信噪比的目的。
本发明实施例中，旋转碟式磁场强探头包括非磁性转轮、4N个第一软磁扇区、M个第二软磁扇区、参考信号发生器以及X轴、Y轴和Z轴磁阻传感器，第一软磁扇区和第二软磁扇区均位于非磁性转轮上，X轴、Y轴和Z轴磁阻传感器位于非磁性转轮的上方或下 方位置处。工作时，非磁性转轮以频率f绕z轴旋转，外磁场经第一软磁扇区调制成频率为4N×f的敏感磁场分量Hx和Hy，外磁场还经第二软磁扇区调制成频率为M×f的敏感磁场分量Hz，该三个敏感磁场分量Hx、Hy和Hz分别经过该X轴、Y轴和Z轴磁阻传感器输出对应的测量信号，参考信号发生器输出频率为4N×f的第一参考信号和M×f的第二参考信号，第一参考信号、第二参考信号和测量信号经外部处理电路解调输出磁场值Hx、Hy和Hz，以此对三维磁场信号的高信噪比进行测量。本发明实施例中，旋转蝶式磁场强探头将静止磁场调制成高频磁场，在高频磁场中进行测量，这样可以有效克服隧道磁阻(TMR)磁阻传感器直流漂移引起的噪声，消除直流offset的影响，大大降低TMR磁阻传感器使用的噪声。并且该测量结构制作方法简单，只要在磁阻传感器外加一个旋转软磁探头即可实现，降低了测量结构的复杂性和尺寸，该测量结构对于地磁场的监控及信噪比的提高具有使用价值。
示例性的，在上述技术方案的基础上，结合图1～图4所示可选非磁性转轮2具有4N个第一光入射孔10和M个第二光入射孔11，4N个第一光入射孔10的柱坐标分别为(r(r＝r e1),α(α＝θ&θ+90°/N&θ+2×90°/N…&θ+(i-1)×90°/N…&θ+(4N-1)×90°/N)，z[z 0,z 0+th 1])，M个第二光入射孔11的柱坐标分别为(r(r＝r e2)，α(α＝θ 1&θ 1+360°/M&θ 1+2×360°/M…&θ 1+(i-1)×360°/M…&θ 1+(M-1)×360°/M)，z[z 0,z 0+th 1])，其中，r 1<r e1，r 1<r e2；
参考信号发生器包括：第一发光元件161、第二发光元件162、第一光探测器14、第二光探测器15、第一逻辑触发电路和第二逻辑触发电路，第一发光元件161位于第一光入射孔10上方或者下方位置处，第二发光元件162位于第二光入射孔11上方或者下方位置处，第一光探测器14位于第一光入射孔10与第一发光元件161相对的另一侧位置处，第二光探测器15位于第二光入射孔11与第二发光元件162相对的另一侧位置处；
工作时，非磁性转轮2以频率f绕z轴旋转，当第一光入射孔10和第二光入射孔11依次正对第一发光元件161和第二发光元件162时，第一光探测器14触发第一逻辑触发电路输出频率4N×f的第一参考信号以及第二光探测器15触发第二逻辑触发电路输出频率M×f的第二参考信号。本实施例沿用上述附图和附图标记。
本实施例中，设定N＝2，则8个第一光入射孔10贯穿非磁性转轮2的上下表面，分别为10(1)～10(8)，原始状态下xy坐标第一象限内紧邻+X轴的一第一光入射孔10或者与+X轴交叠的一第一光入射孔10标记为10(1)，剩余7个逆时针依次标记为10(2)～10(8)，可以理解，随着非磁性转轮2的旋转，10(1)会旋转至不同位置。该8个第一光入射孔10的柱坐标分别为(r(r＝r e1)，α(α＝θ)，z[z 0,z 0+th 1])，(r(r＝r e1)，α(α＝θ+45°)，z[z 0,z 0+th 1])，(r(r＝r e1)， α(α＝θ+90°)，z[z 0,z 0+th 1])，(r(r＝r e1)，α(α＝θ+135°)，z[z 0,z 0+th 1])，(r(r＝r e1)，α(α＝θ+180°)，z[z 0,z 0+th 1])，(r(r＝r e1)，α(α＝θ+225°)，z[z 0,z 0+th 1])，(r(r＝r e1)，α(α＝θ+270°)，z[z 0,z 0+th 1])，(r(r＝r e1)，α(α＝θ+315°)，z[z 0,z 0+th 1])。
本实施例中，设定M＝5，则5个第二光入射孔11贯穿非磁性转轮2的上下表面，分别为11(1)～11(5)，原始状态下xy坐标第一象限内紧邻+X轴的一第二光入射孔11或者与+X轴交叠的一第二光入射孔11标记为11(1)，剩余4个逆时针依次标记为11(2)～11(5)，可以理解，随着非磁性转轮2的旋转，11(1)会旋转至不同位置。该5个第二光入射孔11的柱坐标分别为(r(r＝r e2)，α(α＝θ 1)，z[z 0,z 0+th 1])，(r(r＝r e2)，α(α＝θ 1+72°)，z[z 0,z 0+th 1])，(r(r＝r e2)，α(α＝θ 1+144°)，z[z 0,z 0+th 1])，(r(r＝r e2)，α(α＝θ 1+216°)，z[z 0,z 0+th 1])，(r(r＝r e2)，α(α＝θ 1+288°)，z[z 0,z 0+th 1])。
本实施例中，参考信号发生器包括两个发光元件和两个光探测器，分别为第一发光元件161和第二发光元件162以及第一光探测器14和第二光探测器15，发光元件和光探测器分别位于非磁性转轮2的两侧，以便于光探测器通过光入射孔探测发光元件发出的光线。可选光探测器和磁阻传感器位于非磁性转轮2的同一侧。
如图2所示可选第一发光元件161位于第一光入射孔10上方位置处，第二发光元件162位于第二光入射孔11上方位置处，第一光探测器14位于第一光入射孔10下方位置处，第二光探测器15位于第二光入射孔11下方位置处。在其他实施例中，如图3所示还可选第一发光元件161位于第一光入射孔10下方位置处，第二发光元件162位于第二光入射孔11下方位置处，第一光探测器14位于第一光入射孔10上方位置处，第二光探测器15位于第二光入射孔11上方位置处。可选发光元件为LED灯或其他任意一种适用的发光元件。可以理解，发光元件和光探测器的位置确定之后固定不变。
工作时，转轴12以频率f旋转以同步带动非磁性转轮2以频率f绕z轴旋转，则非磁性转轮2上的光入射孔的位置发生旋转。当第一光入射孔10和第二光入射孔11旋转至依次正对第一发光元件161和第二发光元件162时，位于第一光入射孔10下方的第一光探测器14可以探测到第一发光元件161发出的光线，则第一光探测器14触发第一逻辑触发电路输出频率4N×f的第一参考信号，位于第二光入射孔11下方的第二光探测器15可以探测到第二发光元件162发出的光线，则第二光探测器15触发第二逻辑触发电路输出频率M×f的第二参考信号。
可选第一参考信号和第二参考信号均为高电平或低电平信号；在第一光探测器探测到第一发光元件发出的光线之前，第一逻辑触发电路的电平保持不变，在第一光探测器探测 到第一发光元件发出的光线之后，第一逻辑触发电路的电平发生转换；在第二光探测器探测到第二发光元件发出的光线之前，第二逻辑触发电路的电平保持不变，在第二光探测器探测到第二发光元件发出的光线之后，第二逻辑触发电路的电平发生转换。
可以理解，若非磁性转轮2旋转至第一发光元件161、第一光入射孔10与第一光探测器14面向设置的情况下，第一光探测器14可以探测到第一发光元件151的光线并触发第一逻辑触发电路，则第一逻辑触发电路切换输出的第一参考信号的电平；若非磁性转轮2旋转至第一发光元件161、第一光入射孔10与第一光探测器14交错的情况下，第一光探测器14无法探测到第一发光元件161的光线，则第一逻辑触发电路保持第一参考信号的电平不变。第二参考信号的切换过程与第一参考信号的切换过程完全相同，在此不再赘述。
具体的，工作时，非磁性转轮2以频率f绕z轴旋转，光入射孔的位置发生变化。当第一光入射孔10(1)正对第一发光元件161时，第一光探测器14探测到第一发光元件161的光线并将该光信号转变为电信号，从而能够探测到非磁性转轮2的角位移，并触发第一逻辑触发电路输出频率为4N×f的第一参考信号，可选该第一参考信号的电平为高电平，并保持输出；顺序的，当第一光入射孔10(2)正对第一发光元件161时，第一光探测器14探测到第一发光元件161的光线并将该光信号转变为电信号，从而能够探测到非磁性转轮2的角位移，并触发第一逻辑触发电路切换第一参考信号的电平，此时第一参考信号从高电平切换为4N×f频率的低电平，并保持输出；以此类推，当第一光入射孔10正对第一发光元件161时，第一光探测器14触发第一逻辑触发电路切换第一参考信号的电平，当第一光入射孔10与第一发光元件161交错时，第一逻辑触发电路输出的第一参考信号的电平保持不变。由此可知，第一逻辑触发电路输出频率为4N×f的由高电平和低电平组成的第一参考信号。
同理，基于第二发光元件162、第二光入射孔11和第二光探测器15，第二逻辑触发电路输出频率为M×f的由高电平和低电平组成的第二参考信号。
可选第一光探测器14、第二光探测器15、X轴磁阻传感器7和8、Y轴磁阻传感器5和6以及Z轴磁阻传感器9位于同一电路板13上。可以理解，光探测器、磁阻传感器、逻辑触发电路等结构均位于同一电路板13上，逻辑触发电路与对应的光探测器电连接，但并不具体限定逻辑触发电路的柱坐标。
示例性的，在上述技术方案的基础上，可选参考信号发生器包括模拟角度传感器和倍频器；模拟角度传感器监控非磁性转轮的旋转，并输出随角度变化的正弦或余弦周期信号， 再通过倍频器分别输出频率为4N×f的第一参考信号和频率为M×f的第二参考信号。与上述实施例不同，本实施例中参考信号发生器可以设置在转轴上。参考信号发生器包含模拟角度传感器，该模拟角度传感器可以用于检测转轴的转动，根据转轴的旋转角度输出频率为f的正弦或者余弦信号。参考信号发生器还包括倍频器，频率为f的正弦或者余弦信号经过倍频器分别生成频率为4N×f的第一参考信号和频率为M×f的第二参考信号。
示例性的，在上述技术方案的基础上，可选X轴磁阻传感器、Y轴磁阻传感器、Z轴磁阻传感器均为隧道磁阻线性传感器。
如图10所示可选外部处理电路包括第一锁相电路24、第二锁相电路28和第三锁相电路26；Y轴磁阻传感器5和6的测量信号经过第一电容20耦合输出到第一锁相电路24，X轴磁阻传感器7和8的测量信号经过第二电容22耦合输出到第二锁相电路28，Z轴磁阻传感器9的测量信号经过第三电容21耦合输出到第三锁相电路26，其中，锁相电路均包含混频器和低通滤波器，第一锁相电路24和第二锁相电路28的低通滤波器的截止频率均小于4N×f，第三锁相电路26的低通滤波器的截止频率小于M×f。
可选外部处理电路还包括前置放大器，前置放大器设置在电容和锁相电路之间。如图11所示，待测量物理量43即测量信号经过调制传感器44形成频率为f的信号，其中包括高频载波信号源Vac和与其相应的传感器441。锁相电路42可选为锁相放大器或锁相环，包括混频器421和低通滤波器422，调制传感器44输出的调制信号经过一个带噪声放大器45进行信号放大，得到信号频率为f的信号，其中，噪声放大器45即为前置放大器。然后，高频载波信号源Vac直接输出一个具有频率为f信号的同频率参考信号，该参考信号输入到混频器421，混频后得到一个高频信号和一个低频信号，而后通过低通滤波器422去掉低频部分。由于噪声信号不会发生频移，所以放大器45的噪声也被过滤掉，最后得到没有放大器噪声的高频输出信号46。
如图10所示可选第一参考信号分别连接到第一锁相电路24和第二锁相电路28，第一锁相电路24输出与外磁场H的Y轴磁场分量对应的Vy信号，第二锁相电路28输出与外磁场H的X轴磁场分量对应的Vx信号；第二参考信号连接到第三锁相电路26，第三锁相电路26输出与外磁场H的Z轴磁场分量对应的Vz信号。可选锁相电路为图中所示锁相放大器。
如上所述，第一光入射孔10(1)在第一发光元件161的照射下，第一光电探测器14将非磁性转轮2旋转的频率f转变成4N×f的第一参考信号。第二光入射孔11(1)在第二发光元件162的照射下，第二光电探测器15将非磁性转轮2旋转的频率f转变成M×f的第二参考 信号。其中，第一参考信号分别传输至触发器23和触发器27，经触发器23输入到锁相放大器24的参考信号输入端，用于后续得到对应Y轴磁阻传感器的测量信号，经触发器27输入到锁相放大器28的参考信号输入端，用于后续得到对应X轴磁阻传感器的测量信号。第二参考信号被传输至触发器25，经触发器25输入到锁相放大器26的参考信号输入端，用于后续得到对应Z轴磁阻传感器的测量信号。
另一方面，X轴磁阻传感器7，Y轴磁阻传感器5和Z轴磁阻传感器9接收到的敏感磁场分量Hx、Hy和Hz分别转变成频率为4N×f，4N×f和M×f的电信号，并分别经过耦合电容即第一电容20、第二电容22和第三电容21后输入到锁相放大器24、26和28的测量信号输入端。这样锁相放大器24根据触发器23输出的第一参考信号和Y轴磁阻传感器5的Y轴测量信号，得到Y轴磁场分量的输出信号Vy；锁相放大器28根据触发器27输出的第一参考信号和X轴磁阻传感器7的X轴测量信号，得到X轴磁场分量的输出信号Vx，锁相放大器26根据触发器25输出的第二参考信号和Z轴磁阻传感器的Z轴测量信号，得到Z轴磁场分量的输出信号，从而最终得到外磁场的矢量值。
锁相放大器24、26和28对应的参考信号为脉冲形式，光电探测器14和15接受到的光信号用于激发触发器23、25和27，而后分别输出高电平和低电平。光探测器每接受到一次LED入射光，则进行高低电平反转触发，即开始时低电平，在接受到LED入射光之前，一直保持低电平，接受到LED入射光后切换为高电平，并且一直保持高电平，直到接受到下一次LED入射光，再次从高电平变成低电平。
示例性的，在上述技术方案的基础上，如图12和图13所示可选非磁性转轮2通过磁屏蔽电机29驱动产生旋转，非磁性转轮2和磁屏蔽电机29通过非磁性传动轴12连接，磁屏蔽电机29表面覆盖一层金属导电层291，磁屏蔽电机291的靠近非磁性转轮2的一侧覆盖软磁金属层292进行磁屏蔽。可选第一软磁扇区3、第二软磁扇区4以及软磁金属层292均为软磁合金材料。
本实施例中，磁屏蔽电机29通过非磁性传动轴即转轴12来驱动非磁性转轮2旋转。磁屏蔽电机29包括电机293以及连接电机293和非磁性转轮2的转轴12，还包括包在电机293表面的金属导电屏蔽层291，其中靠近非磁性转轮2的一侧还贴附有软磁金属层292。非磁性转轮2为非磁性材料，包括塑料、陶瓷、金属和聚合物；第一软磁扇区、第二软磁扇区和软磁金属层为软磁合金材料，即包含Co、Fe、Ni和B、Si、C以及过渡金属Nb、Cu、Zr元素组成的高磁导率软磁材料。软磁金属屏蔽层292用于对电机293的旋转磁场进行屏蔽，以免对非磁性转轮2造成影响。
注意，上述仅为本发明的较佳实施例及所运用技术原理。本领域技术人员会理解，本发明不限于这里所述的特定实施例，对本领域技术人员来说能够进行各种明显的变化、重新调整、相互组合和替代而不会脱离本发明的保护范围。因此，虽然通过以上实施例对本发明进行了较为详细的说明，但是本发明不仅仅限于以上实施例，在不脱离本发明构思的情况下，还可以包括更多其他等效实施例，而本发明的范围由所附的权利要求范围决定。

Claims (11)

  1. 一种旋转碟式磁场强探头，其特征在于，包括：
    非磁性转轮、4N个第一软磁扇区和M个第二软磁扇区，所述第一软磁扇区和所述第二软磁扇区均位于所述非磁性转轮上，所述4N个第一软磁扇区的柱坐标分别为(r[r 1,r 2]，α[Φ 0,90°/N-Φ 0]，z[z 0,z 0+th 1])、(r[r 1,r 2]，α[Φ 0+90°/N，2×90°/N-Φ 0]，z[z 0,z 0+th 1])、(r[r 1,r 2]，α[Φ 0+(i-1)×90°/N,i×90°/N-Φ 0]，z[z 0,z 0+th 1])和(r[r 1,r 2]，α[Φ 0+(4N-1)×90°/N,4N×90°/N-Φ 0]，z[z 0,z 0+th 1])，所述M个第二软磁扇区的柱坐标分别为(r[r 3,r 4]，α[Φ 1,360°/M-Φ 1]，z[z 1,z 1+th 3])、(r[r 3,r 4]，α[Φ 1+360°/M,2×360°/M-Φ 1]，z[z 1,z 1+th 3])、(r[r 3,r 4]，α[Φ 1+(i-1)×360°/M，i×360°/M-Φ 1]，z[z 1,z 1+th 3])和(r[r 3,r 4]，α[Φ 1+(M-1)×360°/M,M×360°/M-Φ 1]，z[z 1,z 1+th 3])；
    位于柱坐标(r(r＝(r 1+r 2)/2)，α(α＝0°&180°)，z[(z＝z 0-th 2)|(z＝z 0+th 1+th 2)])位置处的Y轴磁阻传感器；
    位于柱坐标(r(r＝(r 1+r 2)/2)，α(α＝90°&270°)，z[(z＝z 0-th 2)|(z＝z 0+th 1+th 2)])位置处的X轴磁阻传感器；
    位于柱坐标(r(r＝(r 3+r 4)/2),α[(α＝180°/M)|(α＝3×180°/M)|…|(α＝(2i-1)×180°/M)|…|(α＝(2M-1)×360°/M)|(α＝(M-1)×360°/M)]，z[(z＝z 1-th 4)|(z＝z 1+th 3+th 4)])位置处的Z轴磁阻传感器；
    以及参考信号发生器，其中4N/M和M/4N均为非整数；
    工作时，所述非磁性转轮以频率f绕z轴旋转，外磁场H经所述第一软磁扇区调制成频率为4N×f的敏感磁场分量Hx和Hy，所述外磁场H还经所述第二软磁扇区调制成频率为M×f的敏感磁场分量Hz，该三个敏感磁场分量Hx、Hy和Hz分别经过该X轴、Y轴和Z轴磁阻传感器输出对应的测量信号，所述参考信号发生器输出频率为4N×f的第一参考信号和M×f的第二参考信号，所述第一参考信号、所述第二参考信号和所述测量信号经外部处理电路解调输出磁场值Hx、Hy和Hz，以此对三维磁场信号的高信噪比进行测量。
  2. 根据权利要求1所述的旋转碟式磁场强探头，其特征在于，所述非磁性转轮具有4N个第一光入射孔和M个第二光入射孔，所述4N个第一光入射孔的柱坐标分别为(r(r＝r e1)，α(α＝θ&θ+90°/N&θ+2×90°/N…&θ+(i-1)×90°/N…&θ+(4N-1)×90°/N)，z[z 0,z 0+th 1])，所述M个第二光入射孔的柱坐标分别为(r(r＝r e2)，α(α＝θ 1&θ 1+360°/M&θ 1+2×360°/M…&θ 1+(i-1)×360°/M…&θ 1+(M-1)×360°/M)，z[z 0,z 0+th 1])，其中，r 1<r e1，r 1<r e2；
    所述参考信号发生器包括：第一发光元件、第二发光元件、第一光探测器、第二光探测器、第一逻辑触发电路和第二逻辑触发电路，所述第一发光元件位于所述第一光入射孔 上方或者下方位置处，所述第二发光元件位于所述第二光入射孔上方或者下方位置处，所述第一光探测器位于所述第一光入射孔与所述第一发光元件相对的另一侧位置处，所述第二光探测器位于所述第二光入射孔与所述第二发光元件相对的另一侧位置处；
    工作时，所述非磁性转轮以频率f绕z轴旋转，当所述第一光入射孔和所述第二光入射孔依次正对所述第一发光元件和所述第二发光元件时，所述第一光探测器触发所述第一逻辑触发电路输出频率4N×f的所述第一参考信号以及所述第二光探测器触发所述第二逻辑触发电路输出频率M×f的所述第二参考信号。
  3. 根据权利要求1所述的旋转碟式磁场强探头，其特征在于，所述参考信号发生器包括模拟角度传感器和倍频器；
    所述模拟角度传感器监控所述非磁性转轮的旋转，并输出随角度变化的正弦或余弦周期信号，再通过所述倍频器分别输出频率为4N×f的所述第一参考信号和频率为M×f的所述第二参考信号。
  4. 根据权利要求2所述的旋转碟式磁场强探头，其特征在于，所述第一参考信号和所述第二参考信号均为高电平或低电平信号；
    在所述第一光探测器探测到所述第一发光元件发出的光线之前，所述第一逻辑触发电路的电平保持不变，在所述第一光探测器探测到所述第一发光元件发出的光线之后，所述第一逻辑触发电路的电平发生转换；
    在所述第二光探测器探测到所述第二发光元件发出的光线之前，所述第二逻辑触发电路的电平保持不变，在所述第二光探测器探测到所述第二发光元件发出的光线之后，所述第二逻辑触发电路的电平发生转换。
  5. 根据权利要求2所述的旋转碟式磁场强探头，其特征在于，所述第一光探测器、所述第二光探测器、所述X轴磁阻传感器、所述Y轴磁阻传感器和所述Z轴磁阻传感器位于同一电路板上。
  6. 根据权利要求1所述的旋转碟式磁场强探头，其特征在于，所述X轴磁阻传感器、所述Y轴磁阻传感器、所述Z轴磁阻传感器均为隧道磁阻线性传感器。
  7. 根据权利要求6所述的旋转碟式磁场强探头，其特征在于，所述外部处理电路包括第一锁相电路、第二锁相电路和第三锁相电路；
    所述Y轴磁阻传感器的测量信号经过第一电容耦合输出到所述第一锁相电路，所述X轴磁阻传感器的测量信号经过第二电容耦合输出到所述第二锁相电路，所述Z轴磁阻传感器的测量信号经过第三电容耦合输出到所述第三锁相电路，其中，锁相电路均包含混频器 和低通滤波器，所述第一锁相电路和所述第二锁相电路的低通滤波器的截止频率均小于4N×f，所述第三锁相电路的低通滤波器的截止频率小于M×f。
  8. 根据权利要求7所述的旋转碟式磁场强探头，其特征在于，所述外部处理电路还包括前置放大器，所述前置放大器设置在所述电容和所述锁相电路之间。
  9. 根据权利要求7或8所述的旋转碟式磁场强探头，其特征在于，所述第一参考信号分别连接到所述第一锁相电路和所述第二锁相电路，所述第一锁相电路输出与所述外磁场H的Y轴磁场分量对应的Vy信号，所述第二锁相电路输出与所述外磁场H的X轴磁场分量对应的Vx信号；
    所述第二参考信号连接到所述第三锁相电路，所述第三锁相电路输出与所述外磁场H的Z轴磁场分量对应的Vz信号。
  10. 根据权利要求1所述的旋转碟式磁场强探头，其特征在于，所述非磁性转轮通过磁屏蔽电机驱动产生旋转，所述非磁性转轮和所述磁屏蔽电机通过非磁性传动轴连接，所述磁屏蔽电机表面覆盖一层金属导电层，所述磁屏蔽电机的靠近所述非磁性转轮的一侧覆盖软磁金属层进行磁屏蔽。
  11. 根据权利要求10所述的旋转碟式磁场强探头，其特征在于，所述第一软磁扇区、所述第二软磁扇区以及所述软磁金属层均为软磁合金材料。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117741524A (zh) * 2023-12-21 2024-03-22 迈胜医疗设备有限公司 自动化全内置超导磁铁磁场强度测量装置及测量方法

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111505545B (zh) * 2020-04-30 2022-02-18 江苏多维科技有限公司 一种机电调制磁阻旋转式磁场强探头
CN111537924B (zh) * 2020-05-13 2022-02-08 江苏多维科技有限公司 一种旋转碟式磁场强探头

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US365398A (en) 1887-06-28 Cultivator
US20100231211A1 (en) * 2009-02-04 2010-09-16 U.S. Government As Represented By The Secretary Of The Army Magnetic sensor method and apparatus
US20110062956A1 (en) * 2008-08-14 2011-03-17 U.S. Government As Represented By The Secretary Of The Army Mems device with supplemental flux concentrator
CN105487027A (zh) * 2016-01-04 2016-04-13 中国科学院物理研究所 三维矢量磁矩测量仪
CN108413992A (zh) * 2018-01-30 2018-08-17 江苏多维科技有限公司 一种三轴预调制低噪声磁电阻传感器
CN108414951A (zh) * 2018-03-13 2018-08-17 海宁嘉晨汽车电子技术有限公司 周期性调制磁传感器灵敏度降低器件噪声的方法及装置
CN110873851A (zh) * 2018-08-31 2020-03-10 国仪量子(合肥)技术有限公司 磁场测量系统和磁场测量方法
CN111537924A (zh) * 2020-05-13 2020-08-14 江苏多维科技有限公司 一种旋转碟式磁场强探头

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5818227A (en) 1996-02-22 1998-10-06 Analog Devices, Inc. Rotatable micromachined device for sensing magnetic fields
US6501268B1 (en) * 2000-08-18 2002-12-31 The United States Of America As Represented By The Secretary Of The Army Magnetic sensor with modulating flux concentrator for 1/f noise reduction
JP2008151534A (ja) 2006-12-14 2008-07-03 Chiba Univ 磁束測定法及び磁気センサー
US7915891B2 (en) * 2008-08-14 2011-03-29 The United States Of America As Represented By The Secretary Of The Army MEMS device with tandem flux concentrators and method of modulating flux
JP5434494B2 (ja) 2009-11-10 2014-03-05 株式会社リコー 磁気センサ
US8975891B2 (en) 2011-11-04 2015-03-10 Honeywell International Inc. Apparatus and method for determining in-plane magnetic field components of a magnetic field using a single magnetoresistive sensor
US9069031B2 (en) 2012-03-20 2015-06-30 The Regents Of The University Of California Piezoelectrically actuated magnetic-field sensor
JP2018179589A (ja) 2017-04-05 2018-11-15 株式会社豊田中央研究所 回転速度検出装置

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US365398A (en) 1887-06-28 Cultivator
US20110062956A1 (en) * 2008-08-14 2011-03-17 U.S. Government As Represented By The Secretary Of The Army Mems device with supplemental flux concentrator
US20100231211A1 (en) * 2009-02-04 2010-09-16 U.S. Government As Represented By The Secretary Of The Army Magnetic sensor method and apparatus
CN105487027A (zh) * 2016-01-04 2016-04-13 中国科学院物理研究所 三维矢量磁矩测量仪
CN108413992A (zh) * 2018-01-30 2018-08-17 江苏多维科技有限公司 一种三轴预调制低噪声磁电阻传感器
CN108414951A (zh) * 2018-03-13 2018-08-17 海宁嘉晨汽车电子技术有限公司 周期性调制磁传感器灵敏度降低器件噪声的方法及装置
CN110873851A (zh) * 2018-08-31 2020-03-10 国仪量子(合肥)技术有限公司 磁场测量系统和磁场测量方法
CN111537924A (zh) * 2020-05-13 2020-08-14 江苏多维科技有限公司 一种旋转碟式磁场强探头

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4152027A4

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117741524A (zh) * 2023-12-21 2024-03-22 迈胜医疗设备有限公司 自动化全内置超导磁铁磁场强度测量装置及测量方法
CN117741524B (zh) * 2023-12-21 2024-06-11 迈胜医疗设备有限公司 自动化全内置超导磁铁磁场强度测量装置及测量方法

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