Fluxgate Magnetometer with a Test-Based Operating Algorithm

FERROSOND MAGNITOMETRE WITH TEST

Algorithm of functioning

Developers: D.S. Bryakin I.V.;

d.t. Denisov G.S.

Purpose of development.

Measurements of magnetic fields during geophysical and space research, exploration of minerals.

A brief description of the development.

Currently, there are a number of specific practical problems of applied geophysics, the solution of which requires reliable and accurate measurement of the characteristics of the geomagnetic field.

For these purposes, a ferrosonde magnetometer (FM) with a new test algorithm of functioning, providing the property of invariance of measurement results to changes in the conversion coefficients of FM measuring channels, has been developed.

The parameters of the measured total vector T of the geomagnetic field strength (module T ⁇ and angular coordinates φX, φY, φZ) are determined taking into account the given parameters T0 and cosα according to the results of four measuring procedures implemented at the corresponding spatial measuring positions FM (I, II, III and IV): 1 - when combining the longitudinal axis of FM with the coordinate axis X, fix the values of the synphase U0C and quadrature U0K constituting the total signal U0 from the exit of the FM measurement channel; 2 when combining the longitudinal axis of FM with the coordinate axis Y, the value of the quadrature component of U120K of the total signal U120 from the output of the measuring channel FM is recorded; 3 ⁇ when combining the longitudinal axis of FM with the coordinate axis Z, the value of the quadrature components of U240K of the total signal U240 from the output of the measuring channel FM is recorded; 4 ⁇ - when combining the longitudinal axis of FM with the angular coordinate 2700, the value of the synphase component of U270C of the total signal U270 from the output of the MD measuring channel is recorded, while the values of the angular coordinates of the full vector T are determined from the ratios

a the value of the module of the full vector T of the geomagnetic field strength is determined by the formula

⎟T⎜= .

The measuring algorithm is implemented by means of a specially developed version of FM with a test algorithm of functioning.

Structural block diagram of FM with a test algorithm of functioning:

FM is configured with the possibility of uniform spatial movement through four fixed positions forming the measuring positions of FM and coinciding with the geographical (astronomical) coordinate system XG, YG, ZG and the coordinate axis θ. The movement of the FM from one measuring position to another is carried out by a rotary device based on a stepper motor 11 with a fixed angular frequency ω. With the help of block 8, the moments of passage by the component FM of the coordinate axes XG, YG, ZG, θ are recorded and the necessary synchronization and control of the operation modes of all the main functional nodes of the magnetometer is carried out.

The entire measurement process is realized by one FM by its uniform rotation with an angular velocity ω at an angle α around the Ω axis with angular coordinates αX=αY=αZ=α=arctg(√2), and the vector measurements themselves are carried out under the simultaneous influence of the measured magnetic field T and the auxiliary variable magnetic field T0 directed along the axis of rotation Ω with an angular frequency ω0=ω, synchronized accordingly by the block 8.

Current information about the results of measuring four measuring clocks sequentially, in digital form from the outputs of the ADC 5.1 and 5.2 through the multiplexer 9, is entered into the computing unit 10, which, implementing measuring algorithms, determines the required parameters of the magnetic field T in the form of specific numerical values.

Scope of development.

The magnetometer in question is designed to measure three orthogonal components of a weak magnetic field rigidly linked to the axes of the platform on which it is mounted. With a pre-known orientation of the platform axes, the vector of the studied field is determined using a magnetometer, but if the orientation of the axes is unknown, the measurement data are sufficient to estimate the scalar magnitude of the field. This type of magnetometer in combination with certain types of FM has high reliability, resistance to interference and low power consumption, relatively low weight and dimensions.

Essentially, this FM is a precision null-indicator, with which it is possible to measure the components of the geomagnetic field with high accuracy; to carry out work related to geophysical studies and to determine the magnetic deviation created by various moving objects; to ensure the effective operation of various tracking navigation systems that carry out the appropriate orientation of certain objects along the geomagnetic field.

Technical characteristics of the development.

Field sensitivity, A/m 10-8

Supply voltage, B ± 15

Power consumption, W not more than 0.1

Extensive dimensions:

- sensor unit, mm 500×20

- measuring unit, mm 100×25×10

Weight of kit, kg 0.4

Possible users of development.

Scientific and production associations engaged in geological exploration related to the search and exploration of mineral deposits; scientific organizations and departments related to the development and operation of navigation systems.

A commercial offer to consumers.

It is planned to offer the completed development, as well as all rights to it, to the main manufacturers of similar equipment and organizations engaged in its distribution or operation. In equity participation with the acquirer of this development, organize and supervise production and operation at the facilities of potential consumers.

General view of the FM layout with the test algorithm of functioning:

It's patented.

Patent for invention No. 2624597 RF.

Patent holder: KRSU.

Authors: MD Bryakin I.V.; d.t.n. Denisov G.S.

Contact information

G. Bishkek, Shuy 265

Telephone: (0312) 64-19-58

E-mail: bivas2006@yandex.ru