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CN-121978595-A - Fluxgate sensor for weak magnetic field and integrating temperature monitoring and self-checking functions

CN121978595ACN 121978595 ACN121978595 ACN 121978595ACN-121978595-A

Abstract

A fluxgate sensor with integrated temperature monitoring and self-checking functions for a weak magnetic field is composed of a power supply circuit, a probe module, an excitation circuit, a signal conditioning circuit, a temperature acquisition circuit and a self-checking circuit. The magnetic field sensor has the functions of magnetic field vector measurement, real-time temperature monitoring and self-checking, and meanwhile has the built-in temperature compensation algorithm and online program upgrading capability, so that the problems of large temperature drift error and complex calibration of the traditional magnetic sensor are thoroughly solved, and the maintenance efficiency and the product life cycle after large-scale deployment are greatly improved. The sensor is particularly suitable for the fields of high-end industry and scientific research with strict requirements on measurement precision, environmental adaptability and operation and maintenance cost.

Inventors

  • LI BIN
  • YANG CHANGHONG
  • XIANG PENGFEI
  • HE PENGFEI
  • ZHOU QI

Assignees

  • 西安华舜测量设备有限责任公司

Dates

Publication Date
20260505
Application Date
20260209

Claims (7)

  1. 1. A fluxgate sensor integrating temperature monitoring and self-checking functions for a weak magnetic field is characterized in that the fluxgate sensor (1) is composed of a power circuit (1), a probe module (2), an exciting circuit (4), a signal conditioning circuit (5), a temperature acquisition circuit (6) and a self-checking circuit (7), wherein the power circuit (2) is connected with the exciting circuit (4), the signal conditioning circuit (5), the temperature acquisition circuit (6) and the self-checking circuit (7), the exciting circuit (4) is connected with the probe module (2) and the signal conditioning circuit (5), the probe module (3) is connected with the signal conditioning circuit (5), the temperature acquisition circuit (6) is connected with the probe module (2), and the self-checking circuit (7) is connected with the probe module (2).
  2. 2. The fluxgate sensor for integrated temperature monitoring and self-checking function of weak magnetic field according to claim 1, wherein the power supply circuit (1) performs step-down and filtering treatment to the externally supplied power to supply power to the circuit.
  3. 3. Fluxgate sensor for integrated temperature monitoring and self-checking function of weak magnetic field according to claim 1, characterized by the fact that the probe module (2) integrates a triaxial inductive probe (21), a non-magnetic platinum resistor PT100 (23) and a triaxial self-checking coil (22).
  4. 4. The fluxgate sensor with integrated temperature monitoring and self-checking functions for a weak magnetic field according to claim 1, wherein the exciting circuit (4) comprises an exciting source (41), a frequency multiplication phase shift circuit (42) and a power amplification circuit (43), wherein the exciting source (41) is connected with the frequency multiplication phase shift circuit (42), the frequency multiplication phase shift circuit (42) is connected with the power amplification circuit (43) and the phase sensitive detection circuit (52), and the power amplification circuit (43) is connected with the triaxial induction probe (31).
  5. 5. The fluxgate sensor with integrated temperature monitoring and self-checking functions for weak magnetic fields according to claim 1, wherein the signal conditioning circuit (5) comprises a frequency selecting circuit (51), a phase sensitive detection circuit (52), an integrating circuit (53) and a feedback circuit (54), wherein the triaxial inductive probe (31) is connected with the frequency selecting circuit (51), the frequency selecting circuit (51) is connected with the phase sensitive detection circuit (52), the phase sensitive detection circuit (52) is connected with the frequency doubling phase shifting circuit (42) and the integrating circuit (53), the integrating circuit (53) is connected with the feedback circuit (54), and the feedback circuit (54) is connected with the triaxial inductive probe (21).
  6. 6. The fluxgate sensor with the integrated temperature monitoring and self-checking functions for the weak magnetic field according to claim 1, wherein the temperature acquisition circuit (6) comprises a constant current circuit (61), an MCU main control circuit (62) and an RS485 conversion circuit (63), wherein a signal input end of the constant current circuit (61) is connected with a non-magnetic platinum resistor PT100 (23), a signal output end of the constant current circuit is connected with the MCU main control circuit (62), an output end of the MCU main control circuit (62) is connected with the RS485 conversion circuit (63), and the RS485 conversion circuit (63) is communicated with external equipment.
  7. 7. The fluxgate sensor for integrated temperature monitoring and self-checking function of weak magnetic field according to claim 1, wherein the self-checking circuit (7) comprises an optocoupler isolation circuit (71), an oscillator (72) and a driving circuit (73), wherein the optocoupler isolation circuit (71) is connected with the oscillator (72), the connecting oscillator (72) is connected with the driving circuit (73) through a signal, and the driving circuit (73) is connected with the self-checking coil (22).

Description

Fluxgate sensor for weak magnetic field and integrating temperature monitoring and self-checking functions Technical Field The invention relates to the technical field of weak magnetic field measurement, relates to temperature monitoring for measuring a weak magnetic field, in particular to a fluxgate sensor for integrating temperature monitoring and self-checking functions of the weak magnetic field. Background The fluxgate sensor is a high-precision magnetic field measuring instrument based on the magnetic saturation principle, has the advantages of wide measuring range, high resolution, good stability and the like, and is widely applied to the fields of geophysical exploration, space magnetic field detection, industrial nondestructive detection, navigation systems, biomedicine and the like. With the development of technology, the performance requirements of fluxgate sensors are increasing, especially in terms of long-term stability, reliability and field maintainability. However, conventional fluxgate sensors still face two significant technical bottlenecks in practical applications: (1) The system has high complexity, the sensor outputs an analog voltage signal, and a user is required to design additional data acquisition equipment (comprising an analog filter circuit, an ADC sampling circuit, an MCU and the like) to carry out digital processing, so that the complexity of the system design is increased. When the sensor is matched with data acquisition equipment designed by a user, complex electromagnetic compatibility problems can be generated. (2) The parameter calibration is complex, the fluxgate sensor and the matched data acquisition equipment are subjected to system cascade adjustment calibration, the key parameters such as sensitivity, zero offset and the like obtained by calibration are required to be solidified and stored in a nonvolatile memory of the data acquisition equipment, the serial number of each sensor and the serial number of the data acquisition equipment are required to be in one-to-one correspondence, if the sensor is connected with the unpaired acquisition equipment, the original calibration parameters are invalid, and the system calibration is required to be performed again, so that the measurement accuracy and the data validity can be ensured. (3) An inherent disadvantage of analog signal links is that long-range transmission of analog signals is susceptible to electromagnetic interference, resulting in a reduced signal-to-noise ratio. The links such as an analog integrator have the problem of integral drift, and the long-term stability is affected. Furthermore, analog systems do not facilitate nonlinear correction and advanced algorithmic processing, limiting further improvement in sensor performance. (4) Temperature drift problems the physical and electrical parameters of the core sensing element (e.g., magnetic core) and signal conditioning circuitry (e.g., oscillator, amplifier, phase sensitive detector, etc.) of fluxgate sensors are very sensitive to changes in ambient temperature. The temperature fluctuation can directly cause drift of magnetic permeability, coercive force, inductance and resistance of a coil and performance of a semiconductor component. These variations eventually manifest themselves as zero drift and sensitivity drift of the sensor output signal, collectively referred to as temperature drift, which are the most significant factors affecting fluxgate sensor measurement accuracy and long term stability. The fluxgate sensor inevitably undergoes temperature change in the actual working environment, and the system cannot effectively perform real-time temperature compensation because the temperature of the core part (particularly the magnetic core) of the sensor cannot be sensed accurately in real time. Therefore, the output signal contains temperature errors which cannot be distinguished and eliminated, so that the measured data is unreliable in a high-precision application scene. And when the sensor output drifts, as no temperature data is used as a reference, operation and maintenance personnel can not quickly judge whether the sensor is caused by external magnetic field change, the sensor self fault or simple environmental temperature influence, great difficulty is brought to fault detection and system state monitoring, and the overall reliability of the system is reduced. (5) The magnetic flux gate sensor is used as a key measuring device, and the health of the working state of the magnetic flux gate sensor is very important. Particularly in the safety critical fields of aerospace, unmanned systems and the like, the sensor needs to be ensured to be always in a normal state. However, most existing fluxgate sensors do not have online self-test capability. An operator or system cannot quickly diagnose whether the sensor is malfunctioning without powering down or dismantling. The existing detection method generally depends on periodic off-line calibration or