A dynamic strong magnetic field measurement and recording method and system

Abstract

The present invention relates to a dynamic strong magnetic field measurement and recording method and system, belonging to the technical field of measurement and testing instruments. The method comprises: setting an excitation circuit through a preset dynamic strong magnetic field measurement mode to drive a magnetic field sensor to measure and obtain a magnetic field response signal; performing precision compensation on the linear output voltage of the magnetic field sensor through a signal compensation circuit, and transmitting the processed response signal to a signal measurement circuit, performing signal conditioning on the response signal through the signal measurement circuit to obtain an identification signal, and transmitting the identification signal to an analog-to-digital converter through an analog channel; the analog-to-digital converter converts the response signal into a digital signal and transmits the digital signal to an industrial control mainboard through a serial port bus; the industrial control mainboard performs functional control on the digital signal to obtain a control output signal, and sends the control output signal to a storage communication port and a display port through a data transmission port. The stability of the measured value during dynamic strong magnetic field measurement and recording is enhanced.

Description

Technical Field

[0001] The invention belongs to the technical field of measuring and testing instruments, and in particular relates to a dynamic strong magnetic field measurement and recording method and system. Background Art

[0002] Dynamic strong magnetic field measurement and recording refers to the measurement and recording of magnetic field changes in time and space. In the fields of physics, materials science, life science, engineering applications, earth science research, etc., there is a wide range of research needs for the dynamic characteristics of magnetic fields. For example, dynamic strong magnetic field measurement and recording are required to study the dynamic characteristics of magnetic materials, the impact of magnetic fields on organisms, and the interaction between magnetic fields and matter. With the continuous development of science and technology, the demand for the measurement and recording of dynamic strong magnetic fields is increasing, especially in emerging fields such as nanotechnology, biomedical engineering, and magnetic materials, which put forward higher requirements for the accurate measurement and recording of dynamic strong magnetic fields.

[0003] At present, the dynamic strong magnetic field measurement and recording method still has the following areas for improvement:

[0004] When using an inductive magnetic sensor to measure a dynamic strong magnetic field, the Hall element therein is a wearing part. When it is squeezed, collided, or otherwise subjected to stress during use, it will cause measurement errors and damage. It is greatly affected by temperature and input current, and the measurement accuracy is also affected by zero position error, Hall potential, and internal resistance temperature coefficient. The magnetic sensor is often positioned away from its ideal posture during placement. In particular, when using a three-component magnetic sensor for magnetic field measurement, the three axes of the sensor are oriented in the same direction as the geomagnetic coordinate axes. This requires more time and manpower to perform complicated sensor adjustments, and is limited by the measurement environment, which greatly affects the real-time and stability of dynamic strong magnetic field measurement records. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a dynamic strong magnetic field measurement and recording method:

[0006] S1: Setting the excitation circuit to drive the magnetic field sensor to measure and obtain a magnetic field response signal through a preset dynamic strong magnetic field measurement mode;

[0007] S2: performing precision compensation on the linear output voltage of the magnetic field sensor through a signal compensation circuit, transmitting the processed response signal to a signal measurement circuit, performing signal conditioning on the response signal through the signal measurement circuit to obtain an identification signal, and transmitting the identification signal to an analog-to-digital converter through an analog channel;

[0008] S3: The analog-to-digital converter converts the response signal into a digital signal and transmits the digital signal to the industrial control mainboard via a serial bus;

[0009] S4: The industrial control mainboard performs functional control on the digital signal to obtain a control output signal, and sends the control output signal to the storage communication port and the display port through the data transmission port. The purpose of the present invention can be achieved by the following technical solutions:

[0010] Specifically, the magnetic field sensor includes a three-component magnetic sensor and a single-component magnetic sensor, and the sensing elements of the three-component magnetic sensor and the single-component magnetic sensor are Hall effect sensors.

[0011] Specifically, the accuracy compensation method is:

[0012] Setting a temperature interval according to the operating temperature range of the magnetic field sensor, setting temperature compensation coefficients of different temperature intervals according to the temperature interval, and storing the temperature compensation coefficients in a first register;

[0013] The operating temperature of the magnetic field sensor is detected by a temperature sensor to obtain a temperature sensor output signal, the temperature sensor output signal is converted into a temperature measurement digital signal by a signal conversion circuit, and transmitted to the industrial control mainboard, the industrial control mainboard reads a temperature compensation coefficient corresponding to the temperature measurement digital signal stored in the first register according to the temperature measurement digital signal, stores the read temperature compensation coefficient in a second register, and converts the digital signal stored in the second register into a temperature compensation analog signal by a digital-to-analog converter;

[0014] The Hall plate drive current, the main signal path gain and the static output voltage are adjusted according to the temperature compensation analog signal.

[0015] Specifically, the signal conditioning method is:

[0016] Acquiring an input signal limit value of the analog-to-digital converter, setting a primary filter according to the input signal limit value, and filtering the response signal through the primary filter to obtain an amplitude-adjustable signal;

[0017] A variable gain amplifier is arranged after the primary filter, and the amplitude-adjustable signal is amplified to a dynamic range recognizable by the analog-to-digital converter through a gain value in the variable gain amplifier and a resistance value of a variable resistor network;

[0018] Connecting the single-ended signal output by the variable gain amplifier to the first input terminal of the differential amplifier, connecting the inverse of the single-ended signal to the second input terminal of the differential amplifier, and converting and amplifying the single-ended signal into a differential signal;

[0019] The differential signal is filtered through a level conversion circuit and an anti-aliasing filter circuit to obtain an identification signal.

[0020] Specifically, the functional control categories include range control, interval control, zeroing control, and gradient control;

[0021] The range control is: adjusting the gain value of the variable gain amplifier through the industrial control mainboard, and performing analog-to-digital conversion on the identification signal to increase the signal amplitude; the interval control is: dividing and discretizing the collected digital signal through a moving average filtering algorithm; the zeroing control is: turning off the excitation circuit before signal collection begins; the gradient control is: controlling the slope and change rate of the digital signal.

[0022] Specifically, the signal conversion circuit includes a primary linear conversion circuit and a secondary analog-to-digital conversion circuit; the primary linear conversion circuit is composed of a first transistor, a second transistor, a resistor, and a buffer, and the difference between the base-emitter of the first transistor and the second transistor represents a positive temperature coefficient current. The buffer is used to amplify the temperature sensor output signal, and the temperature sensor output signal is converted into an analog voltage value by setting the size of the resistor. The calculation formula is:

[0023]

[0024] Among them, V T is the analog voltage, k is the Boltzmann constant, T is the temperature value, N is the ratio of the number of the first transistor to the number of the second transistor, R1 and R0 are adjustable resistors, q is the electron charge, V REF A reference voltage with zero temperature coefficient;

[0025] The secondary analog-to-digital conversion circuit is composed of a data selector, an integrator, a comparator and a counter; the analog voltage value is integrated by the integrator, and the time required for the integrated voltage to recover to the initial calculated value of the analog voltage value is quantified into a digital signal; the data selector is used to switch the reference signal of the analog voltage value, and the comparator is used to compare the output voltage of the integrator with the reference signal selected by the data selector. If the output voltage of the integrator is higher than the reference signal, the counter starts counting, and if the output voltage of the integrator is lower than the reference signal, the counter stops counting.

[0026] A dynamic strong magnetic field measurement and recording system, comprising: a magnetic field measurement module, a measurement correction module, an acquisition control module, and a storage and display module;

[0027] The magnetic field measurement module is used to set the excitation circuit to drive the magnetic field sensor to measure and obtain a magnetic field response signal through a preset dynamic strong magnetic field measurement mode;

[0028] The measurement correction module is used to perform precision compensation on the linear output voltage of the magnetic field sensor through a signal compensation circuit, and transmit the processed response signal to a signal measurement circuit, perform signal conditioning on the response signal through the signal measurement circuit to obtain an identification signal, and transmit the identification signal to an analog-to-digital converter through an analog channel;

[0029] The acquisition control module is used to convert the response signal into a digital signal through the analog-to-digital converter and transmit the digital signal to the industrial control mainboard through the serial port bus;

[0030] The storage display module is used to perform functional control on the digital signal through the industrial control mainboard to obtain a control output signal, and send the control output signal to the storage communication port and the display port through the data transmission port.

[0031] The beneficial effects of the present invention are:

[0032] By setting the temperature compensation coefficient according to the working temperature range of the magnetic field sensor, a signal conversion circuit that converts the detected temperature information into a digital signal is designed, and a current with a negative temperature coefficient is used to compensate for the positive temperature coefficient of the sensitivity of the Hall disk. When the temperature changes, the Hall voltage is reduced, the variation range of the static output voltage of the magnetic field sensor is reduced, and the influence of the working temperature of the sensor on the accuracy is suppressed; by filtering the response signal, the single-ended signal of the response signal is converted and amplified into a differential signal, the input offset current is reduced, the influence of the input offset current on the sampling accuracy of the circuit is reduced, and the stability during dynamic strong magnetic field measurement and recording is enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0034] Figure 1 The figure is a structural schematic diagram of a dynamic strong magnetic field measurement and recording system of the present invention. DETAILED DESCRIPTION

[0035] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0036] See also Figure 1 , a dynamic strong magnetic field measurement and recording method and system:

[0037] S1: Setting the excitation circuit to drive the magnetic field sensor to measure and obtain a magnetic field response signal through a preset dynamic strong magnetic field measurement mode;

[0038] S2: performing precision compensation on the linear output voltage of the magnetic field sensor through a signal compensation circuit, transmitting the processed response signal to a signal measurement circuit, performing signal conditioning on the response signal through the signal measurement circuit to obtain an identification signal, and transmitting the identification signal to an analog-to-digital converter through an analog channel;

[0039] S3: The analog-to-digital converter converts the response signal into a digital signal and transmits the digital signal to the industrial control mainboard via a serial bus;

[0040] S4: The industrial control mainboard performs functional control on the digital signal to obtain a control output signal, and sends the control output signal to the storage communication port and the display port through the data transmission port. The purpose of the present invention can be achieved by the following technical solutions:

[0041] Specifically, the magnetic field sensor includes a three-component magnetic sensor and a single-component magnetic sensor, and the sensing elements of the three-component magnetic sensor and the single-component magnetic sensor are Hall effect sensors.

[0042] Specifically, the accuracy compensation method is:

[0043] Setting a temperature interval according to the operating temperature range of the magnetic field sensor, setting temperature compensation coefficients of different temperature intervals according to the temperature interval, and storing the temperature compensation coefficients in a first register;

[0044] The operating temperature of the magnetic field sensor is detected by a temperature sensor to obtain a temperature sensor output signal, the temperature sensor output signal is converted into a temperature measurement digital signal by a signal conversion circuit, and transmitted to the industrial control mainboard, the industrial control mainboard reads a temperature compensation coefficient corresponding to the temperature measurement digital signal stored in the first register according to the temperature measurement digital signal, stores the read temperature compensation coefficient in a second register, and converts the digital signal stored in the second register into a temperature compensation analog signal by a digital-to-analog converter;

[0045] The Hall plate drive current, the main signal path gain and the static output voltage are adjusted according to the temperature compensation analog signal.

[0046] Specifically, the signal conditioning method is:

[0047] Acquiring an input signal limit value of the analog-to-digital converter, setting a primary filter according to the input signal limit value, and filtering the response signal through the primary filter to obtain an amplitude-adjustable signal;

[0048] A variable gain amplifier is arranged after the primary filter, and the amplitude-adjustable signal is amplified to a dynamic range recognizable by the analog-to-digital converter through a gain value in the variable gain amplifier and a resistance value of a variable resistor network;

[0049] Connecting the single-ended signal output by the variable gain amplifier to the first input terminal of the differential amplifier, connecting the inverse of the single-ended signal to the second input terminal of the differential amplifier, and converting and amplifying the single-ended signal into a differential signal;

[0050] The differential signal is filtered through a level conversion circuit and an anti-aliasing filter circuit to obtain an identification signal.

[0051] Specifically, the functional control categories include range control, interval control, zeroing control, and gradient control;

[0052] The range control is: adjusting the gain value of the variable gain amplifier through the industrial control mainboard, and performing analog-to-digital conversion on the identification signal to increase the signal amplitude; the interval control is: dividing and discretizing the collected digital signal through a moving average filtering algorithm; the zeroing control is: turning off the excitation circuit before signal collection begins; the gradient control is: controlling the slope and change rate of the digital signal.

[0053] Specifically, the signal conversion circuit includes a primary linear conversion circuit and a secondary analog-to-digital conversion circuit; the primary linear conversion circuit is composed of a first transistor, a second transistor, a resistor, and a buffer, and the difference between the base-emitter of the first transistor and the second transistor represents a positive temperature coefficient current. The buffer is used to amplify the temperature sensor output signal, and the temperature sensor output signal is converted into an analog voltage value by setting the size of the resistor. The calculation formula is:

[0054]

[0055] Among them, V T is the analog voltage, k is the Boltzmann constant, T is the temperature value, N is the ratio of the number of the first transistor to the number of the second transistor, R1 and R0 are adjustable resistors, q is the electron charge, V REF A reference voltage with zero temperature coefficient;

[0056] The secondary analog-to-digital conversion circuit is composed of a data selector, an integrator, a comparator and a counter; the analog voltage value is integrated by the integrator, and the time required for the integrated voltage to recover to the initial calculated value of the analog voltage value is quantified into a digital signal; the data selector is used to switch the reference signal of the analog voltage value, and the comparator is used to compare the output voltage of the integrator with the reference signal selected by the data selector. If the output voltage of the integrator is higher than the reference signal, the counter starts counting, and if the output voltage of the integrator is lower than the reference signal, the counter stops counting.

[0057] In this embodiment, the offset voltage of the Hall disk is suppressed by combining a rotating current module with a Hall disk array of four Hall disks in parallel; secondly, the chopper stabilization technology of the integrated demodulation operational amplifier is used in the signal processing circuit to suppress the offset voltage and noise of the differential amplifier; finally, digital temperature compensation is used to reduce the influence of temperature on sensitivity and static output voltage. After passing through the modulation module, the Hall voltage is firstly amplified using a preamplifier using a transistor as the input stage, and then the preliminarily amplified differential voltage signal is converted into a differential current signal through a transconductance amplifier, and then the differential current signal is converted back into a differential voltage signal using an integrated demodulation operational amplifier and its resistor feedback network. After passing through a unit gain low-pass filter, the differential voltage signal after two stages of amplification, which contains only a little residual offset, is converted into a single-ended output voltage through the last stage of the output amplifier.

[0058] A dynamic strong magnetic field measurement and recording system, comprising: a magnetic field measurement module, a measurement correction module, an acquisition control module, and a storage and display module;

[0059] The magnetic field measurement module is used to set the excitation circuit to drive the magnetic field sensor to measure and obtain a magnetic field response signal through a preset dynamic strong magnetic field measurement mode;

[0060] The measurement correction module is used to perform precision compensation on the linear output voltage of the magnetic field sensor through a signal compensation circuit, and transmit the processed response signal to a signal measurement circuit, perform signal conditioning on the response signal through the signal measurement circuit to obtain an identification signal, and transmit the identification signal to an analog-to-digital converter through an analog channel;

[0061] The acquisition control module is used to convert the response signal into a digital signal through the analog-to-digital converter and transmit the digital signal to the industrial control mainboard through the serial port bus;

[0062] The storage display module is used to perform functional control on the digital signal through the industrial control mainboard to obtain a control output signal, and send the control output signal to the storage communication port and the display port through the data transmission port.

[0063] In the present embodiment, the instrument uses the STM32H750 industrial control board as the control core, including the Arm Cortex-M7 core (with double-precision floating-point unit). The interface expansion board completes the peripheral interface communication function, which is connected to the industrial control board through a connector. The interface expansion board completes the control of high-precision A / D chip, USB, RS-232, Ethernet communication module, D / A chip, 7-inch LCD module capacitive touch LCD color screen, and accesses the large-capacity FLASH chip for storing magnetic field data. Complete the storage and query function of the instrument magnetic field measurement data. The acquisition control module is mainly composed of M2378-CFN20I industrial control module, 24-bit AD chip ADS1255 circuit, ZLG7290 keyboard control chip circuit, USB peripheral circuit, Ethernet transformer circuit, RS-232 conversion circuit.

[0064] The computer storage medium of the embodiment of the present invention may adopt any combination of one or more computer-readable media. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in combination with an instruction execution system, device or device.

[0065] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0066] The program code included on the computer readable medium can be transmitted with any appropriate medium, including but not limited to wireless, electric wire, optical cable, RF, etc., or any suitable combination of the above. The computer program code for performing the operation of the present invention can be written in one or more programming languages ​​or their combinations, and the programming language includes object-oriented programming languages-such as Java, Smalltalk, C++, and also includes conventional procedural programming languages-such as "C" language or similar programming languages. The program code can be executed completely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on the remote computer, or completely on the remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (for example, using an Internet service provider to connect through the Internet).

[0067] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A dynamic strong magnetic field measurement and recording method, characterized in that: include: S1: Setting the excitation circuit to drive the magnetic field sensor to measure and obtain a magnetic field response signal through a preset dynamic strong magnetic field measurement mode; S2: performing precision compensation on the linear output voltage of the magnetic field sensor through a signal compensation circuit, transmitting the processed magnetic field response signal to a signal measurement circuit, performing signal conditioning on the response signal through the signal measurement circuit to obtain an identification signal, and transmitting the identification signal to an analog-to-digital converter through an analog channel; The accuracy compensation method is: Setting a temperature interval according to the operating temperature range of the magnetic field sensor, setting temperature compensation coefficients of different temperature intervals according to the temperature interval, and storing the temperature compensation coefficients in a first register; The operating temperature of the magnetic field sensor is detected by a temperature sensor to obtain a temperature sensor output signal, the temperature sensor output signal is converted into a temperature measurement digital signal by a signal conversion circuit, and transmitted to the industrial control mainboard, the industrial control mainboard reads a temperature compensation coefficient corresponding to the temperature measurement digital signal stored in the first register according to the temperature measurement digital signal, stores the read temperature compensation coefficient in a second register, and converts the digital signal stored in the second register into a temperature compensation analog signal by a digital-to-analog converter; Adjusting the Hall disk drive current, the main signal path gain, and the static output voltage according to the temperature compensation analog signal; The signal conditioning method is: Acquiring an input signal limit value of the analog-to-digital converter, setting a primary filter according to the input signal limit value, and filtering the response signal through the primary filter to obtain an amplitude-adjustable signal; A variable gain amplifier is arranged after the primary filter, and the amplitude-adjustable signal is amplified to a dynamic range recognizable by the analog-to-digital converter through a gain value in the variable gain amplifier and a resistance value of a variable resistor network; Connecting the single-ended signal output by the variable gain amplifier to the first input terminal of the differential amplifier, connecting the inverse of the single-ended signal to the second input terminal of the differential amplifier, and converting and amplifying the single-ended signal into a differential signal; The differential signal is filtered through a level conversion circuit and an anti-aliasing filter circuit to obtain an identification signal; S3: The analog-to-digital converter converts the response signal into a digital signal and transmits the digital signal to the industrial control mainboard via a serial bus; S4: The industrial control mainboard performs functional control on the digital signal to obtain a control output signal, and sends the control output signal to the storage communication port and the display port through the data transmission port.

2. The dynamic strong magnetic field measurement and recording method according to claim 1, characterized in that: The magnetic field sensor includes a three-component magnetic sensor and a single-component magnetic sensor, and the sensing elements of the three-component magnetic sensor and the single-component magnetic sensor are Hall effect sensors.

3. The dynamic strong magnetic field measurement and recording method according to claim 1, characterized in that: The functional control categories include range control, interval control, zeroing control, and gradient control; The range control is: adjusting the gain value of the variable gain amplifier through the industrial control mainboard, and performing analog-to-digital conversion on the identification signal to increase the signal amplitude; the interval control is: dividing and discretizing the collected digital signal through a moving average filtering algorithm; the zeroing control is: turning off the excitation circuit before signal collection begins; the gradient control is: controlling the slope and change rate of the digital signal.

4. The dynamic strong magnetic field measurement and recording method according to claim 1, characterized in that: The signal conversion circuit includes a primary linear conversion circuit and a secondary analog-to-digital conversion circuit; the primary linear conversion circuit is composed of a first transistor, a second transistor, a resistor, and a buffer, and the difference between the base-emitter of the first transistor and the second transistor represents a positive temperature coefficient current. The buffer is used to amplify the temperature sensor output signal, and the temperature sensor output signal is converted into an analog voltage value by setting the size of the resistor. The calculation formula is: , in, V T is the analog voltage, k is the Boltzmann constant, T is the temperature value, N is the ratio of the number of first transistors to the number of second transistors, R 1. R 0 is the adjustable resistance, q is the electron charge, V REF A reference voltage with zero temperature coefficient; The secondary analog-to-digital conversion circuit is composed of a data selector, an integrator, a comparator and a counter; the analog voltage value is integrated by the integrator, and the time required for the integrated voltage to recover to the initial calculated value of the analog voltage value is quantified into a digital signal; the data selector is used to switch the reference signal of the analog voltage value, and the comparator is used to compare the output voltage of the integrator with the reference signal selected by the data selector. If the output voltage of the integrator is higher than the reference signal, the counter starts counting, and if the output voltage of the integrator is lower than the reference signal, the counter stops counting.

5. A dynamic strong magnetic field measurement and recording system, used to execute the method according to any one of claims 1 to 4, characterized in that: include: Magnetic field measurement module, measurement correction module, acquisition control module, storage and display module; The magnetic field measurement module is used to set the excitation circuit to drive the magnetic field sensor to measure and obtain a magnetic field response signal through a preset dynamic strong magnetic field measurement mode; The measurement correction module is used to perform precision compensation on the linear output voltage of the magnetic field sensor through a signal compensation circuit, and transmit the processed response signal to a signal measurement circuit, perform signal conditioning on the response signal through the signal measurement circuit to obtain an identification signal, and transmit the identification signal to an analog-to-digital converter through an analog channel; The acquisition control module is used to convert the response signal into a digital signal through the analog-to-digital converter and transmit the digital signal to the industrial control mainboard through the serial port bus; The storage display module is used to perform functional control on the digital signal through the industrial control mainboard to obtain a control output signal, and send the control output signal to the storage communication port and the display port through the data transmission port.

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