SU1430900A1 - Method of determining the magnetized body location quadrant - Google Patents

Abstract

The invention is intended for use in geophysical research. dovany x. The purpose of the invention is to increase the accuracy and speed of determining the quadrant of the location of the magnetized body. A device that implements the method contains a three-component magnetometer 1, differentiators of channels X and Y 2 and 3, RS flip-flop 4, blocks 5,6,7 of memory of channels X, Y, Z, blocks 8,9,10 of subtraction, circuit 11 12 comparisons of signs and logical. block 13. Thus, a device implementing the method, in the interval between the first change of sign of the derivative of the longitudinal component and the first subsequent change of the sign across the Un, by comparing the signs of the differences of the longitudinal and the opposite. the river components of the vector of the magnetized body determines the direction of the quadrant axis of the position of the desired body horizontally relative to the straight course of movement of the mobile platform with a three-component magnetometer installed on it, by comparing the signs of the difference of the longitudinal and vertical components determines the direction of the quadrant axis along the vertical, 4 silt Ust.O CPU (L e | h with

Description

The invention relates to methods of magnetic measurements and is intended for use in geophysical surveys.

I The purpose of the invention is to improve the accuracy and speed of determining the quadrant location of the magnetized body.

Fig. 1 shows a block diagram of a device implementing the method; in fig. 2 - timing diagrams of processes in the device that implements the method; Fig. 3 shows the trajectory of the moving platform when searching for a magnetized body; in fig. 4 - the coordinate system and the mutual orientation of the radius of the vector R and the vector of the magnetic moment of the anomaly M.

A device that implements the method contains a three-component magnetometer 1, to the outputs of channels X (longitudinal), Y (transverse) and vertical (vertical) of which are connected respectively the inputs of differentiators 2 and 3 of channels X and Y, the outputs of which are connected to the inputs of RS flip-flop 4, The S input of trigger 4 is connected to the output of differentiator 2 of channel X, and the R input of trigger 4 is connected to the output of differentiator 3 of channel Y, blocks 5–7 of memorizing channels X, Y, Z, respectively, to the recording control inputs of which the output of the differentiator 2; blocks 8 - 10 of the subtraction, the second inputs of which are connected to the k outputs of the memory blocks 5-7, respectively, the output of block 8 of the X channel readout is connected to the inputs of the character comparison circuits 11 and 12, the second inputs of which are connected to the outputs of the subtractors 9 and 10, respectively at that, the codes of the t1 and 12 comparison of characters are connected to the inputs of the logic unit 13c by an indicator, and the third input of the unit 13. is connected to the output of the trigger 4,

The implementation of the method for determining the quadrant of the location of the magnetized body is based on the following presuppositions and ratios.

FIG. 3 shows a typical motion path of a moving platform when searching for a magnetized body. In this mode of motion, the target body can enter the detection zone indicated by the radius R (obviously, the distance of the magnetized te / la detection depends on the sensitivity of the magnetized object).

of the conductor and the magnitude of the magnetic moment of the body indicated in FIG. 3 by the vector M), only in the forward hemisphere relative to the course of the movement of the platform. With continuous measurements of the parameters of the magnetic field in the process of searching for a magnetized body and movement along the trajectory of FIG. 3, the assumption about the possibility of the appearance of the desired body in the rear relative to the course of movement of the hemisphere is false, since some time ago the body inevitably was located in the forward hemisphere during a straight-line movement. Of course, this is a fixed search object.

The task of the method for determining the quadrant of the location of magnetized heat is the need to determine the quadrant in which the vector f lies. This quadrant is uniquely defined by the signs cos and sin, while the sign cos specifies the direction of the axis of the quadrant horizontally, and the sign of sin vertically. Consider the relationships on the basis of which the signs cos and sin can be determined. The vector of the floor of the magnetized body (dipole) at the point of observation in an arbitrary Cartesian coordinate system XYZ, in the center of which the dipole is placed, can be determined from the known prominence:

I

20 25 jq.

35

where Bt, B, 2 are components of the induction field of the sex dipole at the point of observation;

S is the module of the radius vector drawn from the origin to the estrus observation; jU (j is the magnetic constant of vacuum;

RxsR ,, E2 coordinates of the observation point;

 M, M, M2- was to compute the magnetic moment vector M

dipole

In expressions (1) in accordance with FIG. 4 variable values in the case of linear motion of the moving

platforms with constant speed along the X axis will be Ry and R. With this in mind and, introducing the designations of constant values

RJ + ..

fV M / 4i p A;

,

after elementary transformations (1 effusion for components By (t), B. (t), Bj (t) as functions of time in the process of movement are written as follows:

B; (t) A (Ua2t2) t 2 tuU2 2 + (m, cos + iri2sinp t-tnxj;

B, j (t) A (1 + a2t2)

-sn

 -m.yztz-f

It follows from relations (2) that when t changes (i.e., Rj; since) from -00 to +00, a certain point t is reached (the position of the point tg depends on the orientation of the vector L and the components of the vector of the magnetized body B (t), B, (t), Bj (t) ism (5 have their own polarity (the moment of polarity change for B}; (t), By (t), B2 (t) drops at different times). From the expression of scientific research institute (4) it follows that the change in the field of the current values of B (tf), Wu (M),

4-3fVmxCos t + m, - (2R2v) Rp -3tn; R ,, R; jo g (r) is due only to the presence

B2 (t) A (1 + a2t2) G-t-Uyg + 3 Um xsin. t + m .j () + 3my- R ,, Rz, 2)

where m, my, m are the unit vectors of the moment M;

V is the speed of movement. In trigonometric form as a function of the angle if (obviously, the angle ifsin (2lf-n) and cos (2if-) in these expressions is x, because the angle 1 / changes from ot -90 to +90 (see Fig. A) and the function of the soztz does not change its sign when changing i / in these lines. Therefore, starting from a certain moment in time, the behavior of Bj, (i /), By (if), B2 (C is determined mainly by sin ( 2if-ii) and cos (2Lf-i |) in accordance with (A) and

sin (2lf-n) and cos (2if-) in these expressions, since the angle 1 / varies from -90 to +90 (see fig. A) and the function of cosZc with changes of i / in these limits. Lakh does not change its sign. Therefore, starting from a certain moment in time, the behavior of Bj, (i /), By (if), B2 (C) is determined mainly by sin (2if-ii) and cos (2Lf-i |) in accordance with (A) and

the only variable angle in the propagation of the sentence, a, 5, e, g, on the turn of movement along a straight trajectory, O ((, ,, „„ torii, see, fig. A l arctgVt / p) qx Bx, Wu, B after elementary trigonometric transformations are written from (2)

The values of B (i4), B (qi), and B2 (P) can be neglected. Obviously, such a moment in time is the moment when the sign of the derivative of the function B ((f) changes, since the change of sign of this derivative means that the pressure of the function sin (2L / -ti) on the behavior of B; ((yi) exceeded the pressure of its term in the expression (4) From this point on, the behavior of B, j (lf), and Bjd /) is defined as follows:

B, (if). (0.5cosc / + 1.5psin (

B, ((if) C Cos M (1 jScos -sino / M cos (B (i4), B (qi), B2 (H) can be neglected. Obviously, this moment in time is the moment when the sign of the derivative function changes In ((f), since the change of sign of this derivative means that the pressure of the function sin (2L / -ti) on the behavior of B; ((yi) exceeded the pressure of its term in expression (4). From the same moment of behavior B, j (lf) and Bjd /) is defined in the fundamentals-U-cos / S -1, 5pcos (2tf-4) - cosp; here CQs (2 (-i), sign change B2 (4) C-cos 4 (1, .cos (- derivative of B x (H) occurs before -5 -cos3r, "- 1,5pcos (2if-T,) sinp, (3)

-Where

- p (cos2 (); ,, + sin2c cos4 - “); ..1 angle between vertical axis

45

point of traverse, which follows from (2) and (4). Based on the above, one can write down the relations for the signs of the increments of the current components of the field vector of the magnetized body and have a place after changing the sign of the derivative Bx () 5

OU and the projection of the vector M on the plane

the movement formed by the axis OX and the course line of motion (angle i is not shown).

For a compact record and convenience of analysis, we denote the product and the sum of the constant values included in (3) as follows:

o 0,5coso (

, 5 81po (". С08 (-5) -С05Ру";

, 5 sin -sin "„ cos (-5,) - cos ud ,; , 5p.

Then expressions (3) are written as:

B (c) C cos l (a + r.sin (2tf-));

Wu ((/) C-cos Lj (5-r-cos (2tf-n) -co3);

Bj (ip) -C- cos tf (e-r. Cos (2tf-n). Sinp.

(A)

It follows from relations (2) that as t changes (i.e., Rj; since) from -00 to +00 upon reaching a certain point t (the position of the point tg depends on the orientation of the vector L), the components of the vector of the magnetized body B (t), B, (t), Bj (t) change their polarity (the moment of polarity change for B}; (t), By (t), B2 (t) occurs at different times). From expression (4) it follows that the change in the polarity of the current values of B (tf), Vu (M),

g (W) is due only to the presence

jo g (r) is due only to the presence

sin (2lf-n) and cos (2if-) in these expressions, since the angle 1 / varies from -90 to +90 (see fig. A) and the function of cosZc with changes of i / in these limits. Lakh does not change its sign. Therefore, starting from a certain moment in time, the behavior of Bj, (i /), By (if), B2 (C) is determined mainly by sin (2if-ii) and cos (2Lf-i |) in accordance with (A) and

 Influence with the summation, 5, e, g on the general

 Influence with the summation, 5, e, g on the general

The values of B (i4), B (qi), and B2 (P) can be neglected. Obviously, such a moment in time is the moment when the sign of the derivative of the function B ((f) changes, since the change of sign of this derivative means that the pressure of the function sin (2L / -ti) on the behavior of B; ((yi) exceeded the pressure of its term in the expression (4). From the same moment, the behavior of B, j (lf) and Bjd /) is determined in the fundamentals of CQs (2 (-i), the sign of the derivative of B x (H) changes to do45

point of traverse, which follows from (2) and (4). Based on the above, it is possible to write relationships for the increment signs of the current components of the vector of the field of the magnetized body, having the place after changing the sign of the derivative Bx () 5

sign (4B) sign (sin (.));

sign (dBv,) sign (-cos (2if-i). cost;

signUB2) sign (-cos (2i / -n.) -sinf.

(five)

Based on expressions (5), we can conclude: in the interval between the first change of sign of the derivative of the longitudinal component and the next subsequent change of sign of the derivative of the transverse corresponding vector of the field

50

of a magnetized body by comparing the signs of the differences (increments) of the values of the longitudinal and transverse, as well as the longitudinal and vertical components, one can determine the quadrant of the position of the magnetized body relative to the straight course of movement of the mobile platform with

The process of determining the axis of the quadrant of the location of the magnetized body horizontally, since the process of determining the axis of the quadrant along the vertical proceeds in a similar way. At the entrance of the magnetometer 1 mounted on a moving linear platform, in the field of a magnetized body at the outputs X, Y, Z

with an accumulator up to some point of the trajectory amplitude (diagrams X, Y in figure 2). At the moment of changing the sign of the derived signal X (point A in diagram X), a short pulse is generated at the output of differentiator 2 and the device begins to perform its functions, the device does not care about the time A, because the indicator of the block 13 is gated with the trigger output signal 4, and information on the indicator is not displayed.

The process of forming a short pulse by changing the sign of the derivative

20

thirty

on it by a three-component magnetometer, Q magnetometer 1 signals appear with an arbitrary orientation of the target body (an arbitrary orientation of the magnetized body is given in (5) by an angle}, This conclusion is based on the following:

the increment sign of l By does not depend on the angle;

IB increment sign. depends on

the increment sign 2 depends on sin |;

in the area of increment measurements (between changes of the signs of derivatives В y (tf) and Wu ((), the functions sin (2V-) and COS (24-,) are in phase, that is, they have the same new sign of increments, therefore, 25 signals X carried out as follows or protivogtolozhennost zakov way ..

LV, and BSJ, and also j and JBj depend only on signs cos and sin, respectively, if signs Jb and ЛВу coincide, then-cosI has a sign -, if signs ffbj (ТЛ ЛЁ- are opposite, then COS

has a sign if the signs of g and Bg coincide, then sin c has a sign - if the signs of the LVU and Bj are opposite, then sin has the sign).

The signs cos and sinF uniquely set the quadrant of the location of the magnetized body.

The specific conclusion about the signs of cos and sin depends on the positive directions of the axes of the three-component magnetometer. The quadrant definitions of the location of the body are valid for the positive directions of the axes of the three-component magnetometer, which are shown in Fig. 4. With other positive directions of the magnetometer axes, the above ratios change, for example, if the OZ axis (unlike FIG 4) is oriented vertically downwards, sin has a + sign, if the signs of and By and flH-j are the same, and the sign is - if signs yB and 7. pro35

40

50

The output pulse of differentiator 2 records the current values of the signals X, Y, Z into memory blocks 5 through 7, respectively; trigger 4 is switched to one state (trigger 4 is set to zero state by signal SET. At some distant point where there is no field body sought). In blocks 8 and 9, the values of the signals recorded at point A are subtracted from the current values of the X and Y signals, and blocks 8–10 of the subtraction can be performed based on an analog comparator with a digital output, therefore a digital signal is present at the output of the blocks; ), corresponding to the sign of the difference between the current signal value at the corresponding output of the magnetometer 1 and the recorded signal value at the output of the corresponding storage device, for example, if the difference between the current and recorded signal values Ala X is positive, then the output of block 8 subtraction is level 1, if this difference is negative, then the output of block 8 is level O. To eliminate possible bounce at the output of blocks 9 and tO, which can occur if there are interference on the magnetometer inputs t, biosimilars, etc.

The device (see, fig.t) that implements the method works as follows.

The operation of the device will be considered on the example of the interaction of blocks in the promontory to a certain point of the trajectory amplitude (diagrams X, Y - in figure 2). At the moment of changing the sign of the derived signal X (point A on the diagram X), a short pulse is generated at the output of differentiator 2 and the device begins to perform its functions, the device does not care about time A, since the indicator of unit 13 is gated with the output signal of trigger 4, and information on the indicator is not displayed.

The process of forming a short pulse by changing the sign of the derivative

magnetometer 1 signals appear

The X signal is performed as follows.

0

five

0

0

five

The output pulse of differentiator 2 records the current values of the signals X, Y, Z into memory blocks 5 through 7, respectively; trigger 4 is switched to one state (trigger 4 is set to zero state by signal SET. At some distant point where there is no field body sought). In blocks 8 and 9, the values of the signals recorded at point A are subtracted from the current values of the X and Y signals, and blocks 8–10 of the subtraction can be performed based on an analog comparator with a digital output, therefore a digital signal is present at the output of the blocks; ), corresponding to the sign of the difference between the current signal value at the corresponding output of the magnetometer 1 and the recorded signal value at the output of the corresponding storage device, for example, if the difference between the current and recorded signal values Ala X is positive, then the output of block 8 subtraction is level 1, if this difference is negative, then the output of block 8 is level O. To eliminate possible bounce at the output of blocks 9 and tO, which can occur if there are interference on the magnetometer inputs t, blocks 8-10 can be performed based on a comparator with hysteresis. The signals of blocks 8 and 9 of the subtraction are fed to a character comparison circuit 11, which is a logical Element EXCLUSIVE OR, which can be implemented, for example, on a 155LP5 type microcircuit and is designed to implement the following logic Q function: when the signals at the input coincide, t . when both input signals have levels 1 or O, the output of the character comparison circuit 11 is, for example, 1, if the input signals do not match, i.e. when one of the signals has the level t, and the other has the level O, then the output of the comparison circuit of signs appears level O. Thus, when the signs of the differences between the current and longitudinal and transverse components recorded in the storage blocks 5 and 6 match, at the output of the comparison circuit of characters there is a level 1 ,. if the signs do not match - О ,, which causes the display on the indicator of block 13, respectively, of the readings Body to the right or Body to the left, i.e. determines the direction of the quadrant axis of the horizontal position of the target body. The process of determining the axis of the quadrant vertically proceeds in a similar way, to determine the direction of this axis, the part of the magnetized body is used to determine the direction of the axis of the quadrant of the location of the target body horizontally relative to the linear course of movement of the mobile platform with a three-component magnetometer installed on it, by comparing differences signs the longitudinal and vertical components determine the vertical direction of the quadrant axis.

Claims (1)

Invention Formula 20 The method for determining the quadrant of the HaMarHtrqeHHoro body location, which includes the uninterrupted measurement of the magnetic field of a magnetized body during a linear movement of the magnetometer and the determination of the extremum points of the current values of the magnetic field of the body, characterized in that, in order to improve accuracy and speed, current values are simultaneously measured the longitudinal and transverse and vertical components of the Y-1ZYCH vectors of the magnetic field of a magnetized body at two points of the trajectory of the magnetometer, determine the signs of separation s between the homonymous values of the constituents in the following points and predschuschey trajectory, compare these marks with each other, and measuring the current field values and determining the signs raznos25 1C. -. K And 5.7, 8, 10, diagram 12. Accordingly, these component field vectors are magnetized by the presence of level 1 signs comparing the output of the t2 circuit on the indicator of block 13, for example, the Body is displayed above, if there is a level O - Body below the plane movement. . Thus, the device is realized. The following method performs the following functions: in the interval between the first change of the sign of the derivative of the longitudinal component and the first subsequent change of the sign of the transverse component by comparing the signs of the differences of the longitudinal and transverse components of the century 40 45 The body is made in the interval between the first extremum of the longitudinal component and the next subsequent extremum of the vertical component of the vector of the field of the magnetized body. The axis direction of the quadrant horizontally is determined by comparing the signs of the difference of the longitudinal and pictorial components, and the axis direction of the quadrant along the vertical is determined by comparing the signs of the differences of the longitudinal and vertical components of the magnetic field vector of the magnetized body, The torus of a magnetized body determines the direction of the quadrant axis of the location of the target body horizontally relative to the rectilinear course of the moving platform with a three-component magnetometer installed on it, by comparing the signs of the difference of the longitudinal and vertical components of the quadrant axis axis vertically. Invention Formula The method for determining the quadrant of the HaMarHtrqeHHoro body location, which includes the uninterrupted measurement of the magnetic field of a magnetized body during a linear movement of the magnetometer and the determination of the extremum points of the current values of the magnetic field of the body, characterized in that, in order to improve accuracy and speed, current values are simultaneously measured the longitudinal and transverse and vertical components of the Y-1ZYCH vectors of the magnetic field of a magnetized body at two points of the trajectory of the magnetometer, determine the signs of the difference between the values of the components of the same name at the next and previous points of the trajectory, these signs are compared with each other; moreover, the measurements of the current values of the field and the definition of the signs of the spacing . -. 0 five The body is made in the interval between the first extremum of the longitudinal component and the next subsequent extremum of the vertical component of the vector of the field of the magnetized body. The axis direction of the quadrant horizontally is determined by comparing the signs of the difference of the longitudinal and pictorial components, and the axis direction of the quadrant along the vertical is determined by comparing the signs of the differences of the longitudinal and vertical components of the magnetic field vector of the magnetized body, t / 9.2 / (puff.3 Phil / ft / neither ffffu) ffef / uf