Low-dynamic-noise digital three-axis geomagnetic sensor

Abstract

The invention discloses a low-dynamic-noise digital three-axis geomagnetic sensor, and relates to the technical field of sensors, the low-dynamic-noise digital three-axis geomagnetic sensor is fixed on a support platform of a three-axis non-magnetic turntable, and the support platform is fixed in a magnetic field to-be-detected area; according to the three-axis geomagnetic sensor, a TMR magnetic induction module is adopted to detect a magnetic field to-be-detected area, and a magnetic field intensity analog signal is obtained; and the main circuit module obtains a magnetic field intensity digital signal according to the magnetic field intensity analog signal, obtains correction data according to the magnetic field intensity digital signal, and corrects the TMR magnetic induction module according to the correction data. The TMR magnetic induction module is adopted, the influence of vibration of the platform to be detected on magnetic field detection can be reduced, and the accuracy of magnetic field detection is improved.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a low-noise digital three-axis geomagnetic sensor. Background Art

[0002] The existing digital three-axis geomagnetic sensors mostly use coil-wound magnetic probes. Therefore, when performing magnetic field detection on a non-stationary platform, the vibration of the platform to be detected can easily interfere with the digital three-axis geomagnetic sensor in the measurement, resulting in a large amount of noise in the total magnetic field obtained by the digital three-axis geomagnetic sensor.

[0003] Taking the digital three-axis geomagnetic sensor using a coil-wound magnetic induction probe as an example, during the process of detecting the magnetic field of the platform to be tested, if the platform vibrates, the coil-wound magnetic induction probe will vibrate, causing the analog signal of the magnetic field strength generated by the induction magnetic field in the magnetic field to be detected to be unstable. The vibration will cause the angle between the coil-wound magnetic induction probe itself and the magnetic field to change frequently, ultimately resulting in a large error in the analog signal of the magnetic field strength detected by the digital three-axis geomagnetic sensor using a coil-wound magnetic induction probe.

[0004] Moreover, the existing digital three-axis geomagnetic sensor has no way to protect the coil-wound magnetic induction probe from vibration, so the magnetic field data obtained by the detection will be magnified by external factors such as platform vibration, which ultimately makes the total magnetic field obtained by the digital three-axis geomagnetic sensor have a large noise. Therefore, there is an urgent need for a digital three-axis geomagnetic sensor that can reduce the vibration influence of the platform to be measured, reduce the detected magnetic field noise, and improve the accuracy of magnetic field strength detection. Summary of the invention

[0005] The purpose of the present invention is to provide a low dynamic noise digital three-axis geomagnetic sensor, which can reduce the influence of vibration of the platform to be measured and improve the accuracy of magnetic field detection.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A low-noise digital three-axis geomagnetic sensor, the low-noise digital three-axis geomagnetic sensor is fixed to a support platform of a three-axis non-magnetic turntable, and the support platform is fixed to a magnetic field to be measured area; the three-axis geomagnetic sensor comprises:

[0008] A TMR magnetic induction module is used to detect the magnetic field to be measured in the area to be measured and obtain a magnetic field strength analog signal;

[0009] The main circuit module is connected to the TMR magnetic induction module, and is used to obtain a magnetic field strength digital signal according to the magnetic field strength analog signal, obtain correction data according to the magnetic field strength digital signal, and correct the TMR magnetic induction module according to the correction data.

[0010] Optionally, the TMR magnetic induction module includes:

[0011] An XY-axis magnetic probe submodule is connected to the main circuit module and is used to perform magnetic induction on the X-axis and Y-axis directions of the magnetic field to be measured area to obtain analog signals of magnetic field strength in the X-axis and Y-axis directions;

[0012] The Z-axis magnetic probe submodule is connected to the main circuit module and is used to perform magnetic induction on the Z-axis direction of the magnetic field to be measured area to obtain an analog signal of the magnetic field intensity in the Z-axis direction.

[0013] Optionally, the main circuit module includes:

[0014] The ADC acquisition submodule is connected to the TMR magnetic induction module and is used to discretize the magnetic field strength analog signal to obtain a magnetic field strength digital signal;

[0015] The MCU submodule is connected to the ADC acquisition submodule and is used to obtain correction data according to the magnetic field strength digital signal and to calibrate the TMR magnetic induction module according to the correction data.

[0016] Optionally, the low dynamic noise digital three-axis geomagnetic sensor further includes:

[0017] The display module is connected to the main circuit module and is used to display the digital signal of the magnetic field strength of the magnetic field to be measured area and the correction data.

[0018] Optionally, the low dynamic noise digital three-axis geomagnetic sensor is connected to a terminal device, and the low dynamic noise digital three-axis geomagnetic sensor further includes:

[0019] A communication module is connected to the main circuit module and is used to send the correction data to a terminal device; the terminal device is used to receive the correction data.

[0020] Optionally, the low dynamic noise digital three-axis geomagnetic sensor further includes:

[0021] A power supply module is connected to the TMR magnetic induction module and the main circuit module, and is used to provide electrical energy.

[0022] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0023] The low dynamic noise digital three-axis geomagnetic sensor disclosed in the embodiment of the present invention is fixed on the supporting platform of the three-axis non-magnetic turntable, and the supporting platform is fixed on the magnetic field area to be measured. The three-axis geomagnetic sensor detects the magnetic field area to be measured through the TMR magnetic induction module to obtain the magnetic field strength analog signal of the magnetic field area to be measured; the main circuit module obtains the magnetic field strength digital signal after discretization processing of the magnetic field strength analog signal, obtains correction data according to the magnetic field strength digital signal, and corrects the TMR magnetic induction module according to the correction data.

[0024] Compared with the existing digital three-axis geomagnetic sensor using a coil-wound magnetic induction probe, the present invention uses a TMR magnetic induction module to detect the magnetic field strength analog signal of the magnetic field area to be measured, which can avoid the influence of external factors such as platform vibration on the magnetic field strength analog signal, thereby reducing the noise of the total magnetic field and improving the accuracy of magnetic field detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 This is a connection diagram of the low dynamic noise digital three-axis geomagnetic sensor module of the present invention;

[0027] Figure 2 This is a schematic diagram of the connection of the TMR magnetic sensing module of the low dynamic noise digital three-axis geomagnetic sensor of the present invention;

[0028] Figure 3 This is a schematic diagram of the connection of the main circuit module of the low dynamic noise digital three-axis geomagnetic sensor of the present invention;

[0029] Figure 4 The figure is a schematic diagram of the physical structure of the low dynamic noise digital three-axis geomagnetic sensor of the present invention. DETAILED DESCRIPTION

[0030] 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.

[0031] The object of the present invention is to provide a low dynamic noise digital three-axis geomagnetic sensor, which can reduce the noise of the total magnetic field and improve the accuracy of magnetic field detection.

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 1 As shown, the present invention discloses an embodiment of a low dynamic noise digital three-axis geomagnetic sensor, wherein the low dynamic noise digital three-axis geomagnetic sensor is fixed to a supporting platform of a three-axis non-magnetic turntable, and the supporting platform is fixed to a magnetic field area to be measured; the three-axis geomagnetic sensor comprises: a TMR magnetic induction module 1 and a main circuit module 2.

[0034] The TMR magnetic induction module 1 is used to detect the magnetic field to be measured area to obtain a magnetic field intensity analog signal.

[0035] The main circuit module 2 is connected to the TMR magnetic induction module 1; the main circuit module 2 is used to obtain a magnetic field strength digital signal according to the magnetic field strength analog signal, obtain correction data according to the magnetic field strength digital signal, and correct the TMR magnetic induction module 1 according to the correction data.

[0036] The TMR magnetic induction module 1 and the main circuit module 2 are connected by single-row pin welding. The TMR magnetic induction module 1 and the main circuit module 2 are independent of each other, which is convenient for debugging and maintenance.

[0037] In practice, the application of three-axis geomagnetic sensors is mostly to measure the magnetic field strength in a certain area. Since there is basically a three-dimensional magnetic field in the measurement area, it is necessary to measure the magnetic field strength in at least three directions to confirm the approximate distribution of the magnetic field in the measurement area. Figure 2 In the embodiment of the present invention, the TMR magnetic sensing module 1 includes: an XY axis magnetic probe submodule 11 and a Z axis magnetic probe submodule 12.

[0038] The XY axis magnetic probe submodule 11 is connected to the main circuit module 2; the XY axis magnetic probe submodule 11 is used to perform magnetic induction on the X axis and Y axis directions of the magnetic field to be measured area, and obtain analog signals of magnetic field strength in the X axis and Y axis directions.

[0039] The Z-axis magnetic probe submodule 12 is connected to the main circuit module 2; the Z-axis magnetic probe submodule 12 is used to perform magnetic induction on the Z-axis direction of the magnetic field to be measured area to obtain an analog signal of the magnetic field strength in the Z-axis direction.

[0040] refer to Figure 4In the TMR magnetic sensing module, both the XY-axis magnetic probe submodule 11 and the Z-axis magnetic probe submodule 12 are magnetic probes made of TMR magnetic chips. The XY-axis magnetic probe submodule uses two single-axis magnetic chips welded on the front and back of the PCB board as an XY-axis direction sensing magnetic probe; the Z-axis magnetic probe submodule 12 welds another single-axis magnetic chip on the PCB board as a Z-axis direction sensing magnetic probe. The XY-axis magnetic probe submodule 11 and the Z-axis magnetic probe submodule 12 are orthogonally welded through the slots on the two circuit boards to form a three-axis orthogonal magnetic probe; the XY-axis magnetic probe submodule 11 and the Z-axis magnetic probe submodule 12 are independently connected, and a single row of pins are used for electrical connection with the main circuit module 2, which is convenient for debugging and maintenance.

[0041] In combination with the above-mentioned low-agitation three-axis geomagnetic sensor embodiment of the present invention, the main circuit module 2 includes an ADC signal acquisition module 21 and an MCU module 22. The ADC acquisition submodule 21 discretizes the analog signal output by the TMR magnetic induction module 1; the MCU module 22 is connected to the ADC acquisition submodule 21 via the SPI bus.

[0042] Specifically, the ADC acquisition submodule 21 is connected to the TMR magnetic induction module 1; the ADC acquisition submodule 21 is used to discretize the magnetic field strength analog signal to obtain a magnetic field strength digital signal.

[0043] The MCU submodule 22 is connected to the ADC acquisition submodule 21 , and the MCU submodule 22 is used to obtain correction data according to the magnetic field strength digital signal, and to calibrate the TMR magnetic induction module 1 according to the correction data.

[0044] In order to make magnetic field detection more convenient and improve the efficiency of magnetic field detection, the three-axis geomagnetic sensor also includes: a display module and a communication module, and the three-axis geomagnetic sensor is also connected to a terminal device.

[0045] The display module is connected to the main circuit module and is used to display the digital signal of the magnetic field strength of the magnetic field to be measured area and the correction data.

[0046] The communication module is connected to the main circuit module; the communication module is used to send the low dynamic noise three-axis magnetic induction intensity data to the terminal device.

[0047] The terminal device is used to receive magnetic induction intensity data. By equipping the terminal device, the magnetic induction intensity data can be obtained remotely, thereby improving the convenience of detection.

[0048] The communication module is connected to the main circuit module 2 via the RS485 communication interface of the main circuit module 2, and the correction data is sent from the main circuit module to the terminal device via the RS485 communication interface.

[0049] The three-axis geomagnetic sensor also includes: a power supply module.

[0050] The power supply module is connected to the TMR magnetic induction module 1 and the main circuit module 2 respectively, and the power supply module is used to provide power.

[0051] Specifically, the power supply module is an LDO module. By providing the power supply module, the digital three-axis geomagnetic sensor disclosed in the present invention can operate independently without being restricted by distance, thereby improving the flexibility of detection.

[0052] In order to reduce the volume of the sensor, the present invention can also integrate the main circuit module 2, the communication module and the power supply module. Among them, the main circuit module uses a 24-bit low-power, small-volume, low-noise ADC chip to receive and amplify the magnetic field strength signal detected by the TMR magnetic induction module 2; a low-power, small-volume, low-noise MCU chip with a 32-bit ARM, FLASH and high-speed processing speed is used, and the main circuit module 2 integrates the ADC submodule 21 and the MCU submodule 22 to perform data storage and function execution; the embodiment of the present invention also uses a low-power, small-volume, low-noise LD0 power chip for power supply, and uses an RS485 communication module for data transmission.

[0053] The low dynamic noise digital three-axis geomagnetic sensor disclosed in the present invention is fixed to the support platform of the three-axis non-magnetic turntable, and the support platform is fixed to the magnetic field test area, ready to detect the test area. After the digital three-axis geomagnetic sensor is powered on, the TMR magnetic induction module detects the test area to obtain an analog signal of the magnetic field strength, and the main circuit module obtains a digital signal of the magnetic field strength according to the analog signal of the magnetic field strength, and sends the digital signal of the magnetic field strength to the terminal device and the display module for display, and then performs data recording and storage, and can make corresponding observations to evaluate the magnetic field state of the magnetic field test area.

[0054] When the magnetic field area to be measured vibrates, the main circuit module discretizes the analog signal of the magnetic field strength detected by the TMR magnetic induction module 1 into a digital signal of the magnetic field strength through the ADC acquisition sub-module 21 when no vibration occurs. Then, when vibration occurs, the correction data obtained by the MCU sub-module 22 from the digital signal of the magnetic field strength is processed, and the angle of the supporting platform is changed by rotating the three-axis non-magnetic turntable, thereby achieving the angle adjustment of the TMR magnetic induction module 1 to avoid the influence of the vibration of the magnetic field area to be measured on the magnetic field detection.

[0055] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0056] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A low dynamic noise digital three-axis geomagnetic sensor, characterized in that: The low dynamic noise digital three-axis geomagnetic sensor is fixed to the support platform of the three-axis non-magnetic turntable, and the support platform is fixed to the magnetic field to be measured area; The three-axis geomagnetic sensor comprises: A TMR magnetic induction module is used to detect the magnetic field to be measured in the area to be measured and obtain a magnetic field strength analog signal; The main circuit module is connected to the TMR magnetic induction module, and is used to obtain a magnetic field strength digital signal according to the magnetic field strength analog signal, obtain correction data according to the magnetic field strength digital signal, and correct the TMR magnetic induction module according to the correction data.

2. The low dynamic noise digital three-axis geomagnetic sensor according to claim 1, characterized in that: The TMR magnetic induction module comprises: An XY-axis magnetic probe submodule is connected to the main circuit module and is used to perform magnetic induction on the X-axis and Y-axis directions of the magnetic field to be measured area to obtain analog signals of magnetic field strength in the X-axis and Y-axis directions; The Z-axis magnetic probe submodule is connected to the main circuit module and is used to perform magnetic induction on the Z-axis direction of the magnetic field to be measured area to obtain an analog signal of the magnetic field intensity in the Z-axis direction.

3. The low dynamic noise digital three-axis geomagnetic sensor according to claim 1, characterized in that: The main circuit module comprises: The ADC acquisition submodule is connected to the TMR magnetic induction module and is used to discretize the magnetic field strength analog signal to obtain a magnetic field strength digital signal; The MCU submodule is connected to the ADC acquisition submodule and is used to obtain correction data according to the magnetic field strength digital signal and to calibrate the TMR magnetic induction module according to the correction data.

4. The low dynamic noise digital three-axis geomagnetic sensor according to claim 1, characterized in that: The low dynamic noise digital three-axis geomagnetic sensor also includes: The display module is connected to the main circuit module and is used to display the digital signal of the magnetic field strength of the magnetic field to be measured area and the correction data.

5. The low dynamic noise digital three-axis geomagnetic sensor according to claim 1, characterized in that: The low-noise digital three-axis geomagnetic sensor is connected to a terminal device, and the low-noise digital three-axis geomagnetic sensor further includes: A communication module is connected to the main circuit module and is used to send the correction data to a terminal device; the terminal device is used to receive the correction data.

6. The low dynamic noise digital three-axis geomagnetic sensor according to claim 1, characterized in that: The low dynamic noise digital three-axis geomagnetic sensor also includes: A power supply module is connected to the TMR magnetic induction module and the main circuit module, and is used to provide electrical energy.

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