SU930176A1 - Ferro-probe magnetometer - Google Patents

Description

The invention relates to geophysical instrumentation, and more specifically to magnetometers designed to measure the components and the total vector of the Earth's magnetic field (MPZ).

Known flux-gage magnetometers of compensation type, comprising a thermocomponent flux-gate sensor, isolation and conversion devices, feedback circuit elements and a control device £ l].

Three-component magnetometers make it possible to measure the components of the Earth's magnetic field induction vector. Currently, these devices are widely used in autonomous measuring systems for obtaining information about the components of the Earth's magnetic field induction vector.

The disadvantages of these devices are the inability to continuously provide information about the magnitude of the module of the vector of the magnetic field of the Earth’s magnetic field, the lack of automatic continuous monitoring and the small depth of health monitoring.

Also known are devices containing digital, analog-to-digital and digital-to-analog converters, in which an automatic test of the condition of the converters is carried out by transmitting a test signal through the circuit of these series-connected converters with the input measured signal switched off [2].

The disadvantage of such devices is the interruption of the measurement of the input signal of the sensor during monitoring, the lack of monitoring of the malfunction of the sensors themselves and the relatively large hardware costs of monitoring.

The closest in technical essence to the invention is a digital flux-gate magnetometer for measuring three mutually perpendicular 93ου larnuh components of the magnetic field vector, which has three measuring channels, which are analog-to-digital converters of the sequential 5 balancing, the main nodes of which are a flux-gate comparing device (FSU ), a control device, which is a digital integrator, made on a modem version counter, and converts Code generator in constant compensating current. Depending on the shape of the output signal, flux-gate comparing devices can be with an output in the form of 15 constant voltage. Or with frequencies ₍ with an output [3].

Each measurement channel works as follows.

In the presence of a difference between the measured and compensating magnetic fields, a large, appears on the exit of the flux-gate comparing device. mismatch, which is a digital integrator. converted to code. 25 A code-to-current converter controlled by a digital integrator generates a direct current proportional to the code supplied to the compensation winding of the flux-gate comparing ₃ devices and creating a compensation field there.

At the time of complete compensation of the measured field by the compensating code of the digital integrator is equal to the magnitude of the components of the vector of the magnetic field strength. The digital integrator code is sent to the recording device. A digital magnetometer for tracking and balancing is high. metrological characteristics.

However, the disadvantages of the known device are the lack of continuous output of information about the magnitude of the magnitude of the vector of the magnetic field of the Earth, the lack of automatic continuous monitoring and a small depth of control of the malfunction. The purpose of the invention is to improve the accuracy and speed of measurements.

The goal is achieved by the fact 'that fluxgate magnetometer comprising three measuring channels, each of which is designed as a series-connected fluxgate comparator block with a fluxgate sensor, a digital integrator and the code transmitter into direct current, whose output is connected to ^{June 4} compensating winding sensor fluxgate of the comparator unit; additionally, a digital calculator, a controlled code to current converter, are introduced, and a sensor of the fluxgate comparator unit is introduced into each sensor a control winding, and the outputs of digital integrators are connected to the inputs of a digital computer, the output of which is connected to the input of a controlled code-to-current converter, the first, second, and third outputs of which are connected, respectively, to the control windings of the first, second, and third flux-gate comparison blocks.

The drawing shows a structural diagram of the proposed flux-gate magnetometer.

A flux-gate magnetometer consists of three measuring channels 1, 2, and 3, each of which contains a series-connected flux-gate | comparing unit 4 with a control winding 5 of the flux-gate sensor, a digital integrator 6 and a transducer 7 · The outputs of the digital integrators 6 are connected to the input of the digital computer 8, the output which is connected to the input of the managed Converter 9 code into current. Three outputs of the controlled code-to-current converter 9 are connected to the control windings 5 of the flux-gate sensor of each of channels 1, 2, and 3.

The device operates in the following two modes: mainly or in operation and in control mode.

In the operating mode, the magnitude of the Earth's magnetic field vector is measured.

Each component of the vector is measured by the corresponding measuring channel 1, 2, 3 (1,2 = 1,2, 3 denotes the channel number) by converting by the digital integrator the difference between the measured and compensating magnetic fields at the output of the fluxgate comparing device in the form of a mismatch in the code.

Depending on the type of the selected flux-gate comparing device, the mismatch can be in the form of a pulse repetition rate or in the form of a constant voltage. In the first case, the integration of the mismatch value is carried out by counting pulses on the reversible counter of the digital integrator 6, in the second case, the digital integrator 6 carries out a preliminary conversion of the output analog signal of the flux-gate comparing unit 4 into a pulse-frequency form.

At the time of complete compensation of the measured field by compensating (i.e., at the time of equality of their absolute values), the code Ν ^ from the digital integrator 6 is proportional to the value of the corresponding component of the MPZ tension vector.

In the digital computer 8, the code of the magnitude of the vector module of the stress vector MPZ is determined by calculating the following dependence

N = - / n * + N * + N *.

where N _d = К ₄ Н „, Η _χ = Κ _χ Η _ζ , Ν _% = К ^ Н, are the codes of the components of the MPZ vector;

To ₄ , K ^, To _e - the conversion coefficients of the components of the vector MPZ.

Due to the high speed of the computing process provided by the digital computer 8, a continuous process of measuring the module of the vector MPZ and the delivery of the result to consumers ;.

Monitoring the health of the device consists in periodically checking the values of the coefficients K ^, K ^, K ^ since / as a failure of any incoming node of the measuring channel 1, 2, 3 causes a change in the value of the corresponding transmission coefficient.

The control device is as follows.

In digital computer 8, test reference signals are generated in the form of alternating codes ± Ν 0.1, ± Ν 0.2, + · N 0.3, supplied through a controlled code converter 9 to current, respectively, to the windings of 5 flux-gate comparing units 4. For the full period (cycle) of control of each measuring channel 1, 2, 3, the supply of test signals is carried out twice.

During the first half-cycle, for example, a positive test signal ( ⁺ Nq _{| 1} ') is supplied, in the second half-cycle, a negative polarity (—Νβΐ). In this case, in the corresponding control winding 5 of the sensor of the ferro- probe comparison unit 4, a magnetic field is induced depending on the polarity of the measured field component, which coincides in sign with the measured half-wave in the half-period and opposite in sign. In both cases, an algebraic summation of the measured field, the compensating field, and the field induced by the reference test signal occurs. At the moment of complete compensation of the measured and test magnetic fields by the field of the compensation winding, in both half periods of the control cycle, 8 values Ν ^ · and Nj 'of the corresponding measuring channel are recorded in the digital computer. Measurement Results. Nj and Ν '·, corresponding to the first and second half-periods of the control cycle, can be represented as follows

-k · Ν n KT ^Л О5МЛ 0,1 ^{+ Ν} ο, · ί 'Ν-Γ ^κ ΐ К _ηκτ К _06M j N _t ^N o, i' K-ί Кηκτ оо.M.io, i ^M % * * iίКπκτ ^ οεΜϊ ^ ο, -t the results of the conversion of test signals of the corresponding measuring channel in the first and second, respectively, half-period of the control clock; Kfj _KT “conversion coefficient of the managed code converter 9 into current ;.

^ ΟίΓΜ-ΐ ~ coefficient of conversion of current into magnetic field strength of the control winding 5 of the corresponding measuring channel 1,2, 3 (this value is almost the same and constant in all control windings). By summing and subtracting the quantities Nj and NJ * in a digital calculator, О Ί 1 le о, the measured and control quantities ^N 1 are separated

-n;

^iK PCT ^K O6NM ^'N _0/4 *

Thus, under the condition of a slow change in the measured field (which is feasible in real conditions), the quantity is measured at the same time and the measurement channels are controlled by comparing the codes

_J ₀ N ^{and N} o, -i ^{or "equivalently"} the ^PU comparing the measured values of the transform coefficients K ₄ measurement channels 1,2 and 3 with the theoretical values stored in the digital computer.

In this device, the control of the measuring channels 1, 2, 3 can be carried out both sequentially and by simultaneously supplying test signals to all control windings 5 of the phase-shifting comparison blocks 4.

In addition, it is possible to select (programmatically) 'in the πρ process of operation the optimal value of the values of test signals depending on the current value of the measured value of the MSS, while the values of test signals must satisfy the following requirement ^N o, i * ^N ALOX ~ ^Ν · ί 'where N .. is the maximum permissible code

LAS Kv _w the measured value of the MPZ.

The mathematical problem, including the operations of computing the vector of MPZ, receiving and issuing information, generating test codes and measuring the conversion coefficients of the channels is feasible by any calculator made according to the standard structure, including input-output devices, arithmetic, memory, and control device.

In addition, it is possible to use a specialized microprocessor based on a set of standard microassemblies.

To perform the intended functions, the managed code-to-current converter 9 comprises a standard code-to-current converter and a channel switch.

The ability to automatically measure the conversion coefficients of channels 1, 2, Sv, in turn, provides the ability to automate the adjustment process in normal climatic conditions, which can significantly increase the productivity of the serial production of products containing these devices and the performance of routine maintenance.

The mathematical capabilities of the digital computer can also provide automatic correction of conversion coefficients by framing corrective corrections 10 introduced in the process of calculating the module of the stress vector MPZ.

Claims (1)

The invention relates to geophysical instrumentation, and more specifically to magnetometers, designed to measure the components and the full vector of the magnetic field of the Earth (EMF). Compensated type fluxgate magnetometers are known, containing a three component flux sensor of the extraction and conversion device, feedback circuit elements and a regulating device {J. A three component magnetometer allows measuring the components of the induction vector of the Earth’s magnetic field. At present, these devices are widely used in autonomous measuring systems for obtaining information about the components of the induction vector of the Earth's magnetic field. The disadvantages of these devices are the impossibility of ensuring the continuous output of information about the magnitude of the module of the induction vector of the magnetic FIELD of the Earth, the lack of automatic continuous monitoring and the small depth of health checks. Devices are also known that contain digital, analog-digital and digital-analog converters, in which an automatic test verifies the health of the converters by transmitting through the circuit of these series-connected converters of the test signal when the input measured signal 2j is turned off. The disadvantage of such devices is the interruption of the measurement of the input signal of the sensor during monitoring, the lack of monitoring of the malfunction of the sensors themselves and the relatively large hardware costs for implementing the monitoring. The closest to the technical essence of the invention is a digital fluxgate magnetometer for measuring three mutually perpendicular phono components of the magnetic field strength vector, which has three measuring channels, which are serial-to-analog converters of sequential balancing, which are the fluxgate a comparison device (FSU), a control device, which is a digital integrator, performed on a reversible counter, and a conversion Code to constant DC current. Depending on the shape of the leaked out signal, fluxgate comparing devices can be with a constant voltage output or a frequency, nyui output. Each measurement channel operates as follows. If there is a difference between the measured and compensating magnetic fields at the exit of the fluxgate comparing device, an error value appears, which is converted by the digital integrator into a code. A code-to-current converter, controlled by a digital integrator, generates a direct current proportional to the code supplied to the compensation winding of the flux-gate comparison device and creates a compensation field there. . At the moment of complete compensation of the measured field, the compensating code of the digital integrator is equal to the magnitude of the component of the magnetic field strength vector. The code of the digital rator is fed to the recording device. Digital magnetometer after. This equilibration has high metrological characteristics. However, the disadvantages of the known device are the lack of continuous output of information about the very power of the module of the intensity vector of the earth mantle, the lack of automatic continuous monitoring and the minimum depth of fault monitoring. The purpose of the invention is to improve the accuracy and speed of measurements. The goal is achieved by the fact that a flux-gate magnetometer containing three measuring channels, each of which is made in a series of fluxgate comparing unit with fluxgate probe, is successively connected to a digital integrator and a DC-to-current converter, the output of which is connected to the compensation winding of the fluxgate comparing probe unit , a digital calculator controlled by a converter to current is additionally introduced, and a sensor of the fluxgate comparing unit is inserted into each sensor the control winding, and the outputs of digital integrators are connected to the inputs of the digital calculator, the output of which is connected to the input of the controlled code-to-current converter, the first, second and third outputs of which are connected, respectively, to the control windings of the first, second and third ferrosound comparing blocks. The drawing shows a structural diagram of the proposed fluxgate magnetometer. The fluxgate magnetometer consists of three measuring channels 1, 2 and 3, each of which contains a series-connected fluxgate 1Comparative unit with a control winding 5 of the fluxgate sensor, a digital integrator 6 and a converter 7. The outputs of the digital integrators 6 are connected to the input of the digital calculator 8, the output of which is connected To enter the controlled converter 9 code to current. Three outputs of the controlled converter 9 code into current are connected to the control windings 5 of the fluxgate sensor of each of channels 1, 2 and 3. The device operates in the following two modes: mainly or working and in the control mode. In the operating mode, the modulus of the vector, the intensity of the Earth’s magnetic field, is measured. Each component H of the vector is measured by the corresponding measuring channel 1, 2, 3 (5 1) 2, 3 denotes the channel number) by converting the difference between the measured and compensating magnetic fields at the output of the fluxgate comparing device by the digital integrator into the code . Depending on the type of fluxgate comparing device chosen, the magnitude of the error may be in the form of a pulse repetition rate or in the form of a constant voltage. 3 of the first case, the integration of the error value is performed by counting pulses on a reversible counter of digital 5 integrator 6, in the second case, digital integrator 6 preliminarily converts the output .. analog signal of the fluxgate comparing block k to the frequency-pulse form. At the moment of complete compensation of the measured field compensating (i.e., at the moment of equality of their absolute values), the N code from the digital integrator 6 is proportional to the value of the corresponding component of the EMF intensity vector. In the digital calculator 8, the code of the magnitude of the magnitude vector of the EMF is determined by calculating the following relationship N. 7, 1 where N, Н. N K.H, is the code of the components of the vector of the EMF; K, K, coefficients of transformation of the components of the vector EMF. Due to the high speed of the computational process provided by the digital calculator 8, a continuous process of measuring the module of the EMF vector is performed and the result of the user m1 is output. The health of the device is monitored to periodically check the values of the coefficients K, K-, K "so / as any incoming node fails measuring channels 1,2, 3 causes a change in the value of the corresponding transmission coefficient. The device is monitored as follows. In the digital calculator 8, test reference signals are formed in the form of alternating codes tN 0.1, ± N 0.2, i: N 0.3, fed through a controlled code converter 9 to the current, respectively, into the windings 5 of the ferro probe comparison units. For the full period (cycle) of control of each measuring channel 1, 2, 3, the test signals are applied twice. During the first half-period, for example, a positive test signal (NO.,) Is given, in the second half-period - a negative polarity (, I). In this case, a magnetic field is induced in the corresponding control winding 5 of the probe of the fluxgate comparing unit. the components of the floor, in one half-period coinciding 66 in sign with the measured one, and in the other opposite in sign, In either case, an algebraic summation of the measured floor takes place, compensating for and the field induced by the benchmark test th signal. At the moment of complete compensation of the measured and test magnetic fields by the field of the compensation winding, in both half-periods of the control cycle, 8 values and the corresponding measuring channel are written to the digital calculator. Results measured. Scientific research institutes and N, corresponding to the first and second half-periods of the control cycle, can be represented as follows, K, -Ko5.iNo: N; Ni NoH-N -NK, K FCT OBGAL 0.1, ,,., 1 m NO --- K -XCTT results of the conversion of test signals of the corresponding measuring channel in the first and second half-period of the control cycle, respectively; {1КТ the conversion ratio of the controlled converter 9 of the code into the current ;, oSTM-j the conversion coefficient of the current into the magnetic field strength of the control winding 5 of the corresponding measuring channel 1, 2, 3 (this value is almost the same and constant in all control windings), By summing and subtracting the values of N and N in the digital calculator 8, the measured values are compared to the reference values. N .-- N; - J / .V f Vl i niaoBM 0.11 tkuda i IK PKT OBNM-NO. Thus, under the condition of a slow change of the measured field (which is real in real conditions), the magnitude of the H is measured simultaneously and comparing codes and or, which is the same, by comparing the measured value of the conversion factors K measuring channels 1,2, 3 with the theoretical value stored in the digital calculator. In this device, the monitoring of measuring channels 1, 2, 3 can be carried out both by sequential, Tcik and by simultaneously feeding test signals to all control windings of 5 phase-shifting comparison units 4,. In addition, there is a choice (programmatically) in the process of working the optimal value values of test signals depending on the current value of the measured value of the EMF, while the values of test signals should satisfy the following requirement - N "cc-N, / VVQKC- ° f of the maximum permissible value of The estimated value of the MPZ. The mathematical task, including the operations of calculating the EMF vector, with the mapping and issuing of information, generating test codes and measuring channel conversion factors, is performed by any calculator, performed according to the standard structure, including input / output devices, arithmetic, memory and control device. In addition, it is possible to use a specialized mic processor made on a set of standard microassemblies. To perform the intended functions, the controlled S-to-current converter contains a standard code-to-current converter and a channel switch. The ability to automatically measure conversion factors K for channels 1, 2, 3, in turn, makes it possible to automate the adjustment process under normal climatic conditions, which can significantly increase the productivity of the mass production of products containing these devices and the performance of routine maintenance. The mathematical capabilities of the digital calculator also allow for the automatic correction of the conversion coefficients by FD, {emitting corrective corrections made in the process of calculating the magnitude modulus of the EMF. Claims of Invention A fluxgate magnetometer containing three measuring channels, each of which is made in the form of a series-connected ferrozindovogo comparing unit with a fluxgate sensor, digital integrator and converter of a code into direct current, the output of which is connected to the compensation winding of the gauge of the fluxgate comparing unit, is different that, in order to increase the accuracy and speed of measurements, a digital calculator controlled by a code-to-current converter was additionally introduced, and Each sensor of the fluxgate comparing unit is inserted into the control winding, and the outputs of digital integrators are connected to the inputs of a digital calculator, the output of which is connected to the input of a controlled code-to-current converter, the first, second and third outputs of which are connected respectively to the control windings of the first, second and third ferrosound comparing blocks. Sources of information taken into account during the examination 1.Logachev A.A. and others. Magnetic exploration. L., Nedra, 1979, p. 79-852. USSR author's certificate ff, cl. G About F Z / O, 1977. 3. Semenov N.M., Yakovlev N.I. Digital fluxgate magnetometers. L., Energie, 1978, p. 130-136. ABOUT GIH K f-CZIF - ni: h: vvvv