JPS62167405A - Instrument for measuring magnetism of navigating body - Google Patents

Abstract

PURPOSE:To enable a magnetic distribution to be accurately measured even when the course of a ship deviates from predetermined position and bearing by providing the ship with coils to measure the position and bearing of the navigating body and correcting a magnetic distribution. CONSTITUTION:Magnetic detectors D1-D7 are arranged on a line on the sea bottom 1 at prescribed spaces. A measuring room 30 on the line on land is provided with a main instrument 10. Coils La and Lb are wound in a ship 2 to be measured and the ship 2 is visibly marked so that it can be confirmed at a monitoring point 31 when those coils reach the line. When the ship 2 navigates over the line on which the detectors D1-D7 are arranged, the detecting output of the detectors is stored in storage means at prescribed sampling period. Further, when the positions of the coils La and Lb pass the line, these coils are electrified. On the basis of the detecting output of the detectors D1-D7 obtained when the coils La and Lb are electrified and measured data obtained when the coils are not electrified, the magnetism of the hull of the ship 2 in a position where the coils pass the line can be calculated. Then, the actual passing position of the ship 2 and then the bearing and magnetic moment of the navigating body are calculated and correcting magnetic signals are obtained.

Description

Detailed Description of the Invention (a) Industrial Application Field This invention relates to a magnetic measuring device for a passing object such as a ship, particularly a moving object magnetic measuring device using a plurality of magnetic detectors installed on the seabed. Regarding.

(b) Conventional technology In order to measure the magnetic distribution of magnetic materials constituting the hulls and equipment installed on ships, conventional techniques have been used to
multiple magnetic detectors D1, D2,..., D7.
are arranged in a row at predetermined intervals, and when the hull 2 passes at right angles to the row in which the magnetic detectors D+, Dz, . . . , D7 are arranged, At a predetermined sampling period, the magnetic detector D1. The detection outputs of D2, . . . , D7 are taken into a memory of a control device (not shown) and stored therein.

(c) Problems to be solved by the invention In the above conventional device, the hull 2 is the magnetic detector 2,
The magnetic distribution is measured on the premise that it enters the column line where D2, . It is something. However, ships that actually pass do not necessarily approach the array line of magnetic detectors at right angles, and the position of ships passing through the array line of magnetic detectors is not always at a predetermined position. , the magnetic field often shifted from side to side, which hindered precise measurement of magnetic distribution.

SUMMARY OF THE INVENTION An object of the present invention is to provide a passing body magnetism measurement device that can accurately measure magnetic distribution even if the course of a ship deviates from the planned position and direction.

(d) Means and operation for solving the problem The vehicle magnetism measurement device of the present invention includes a plurality of magnetic detectors (D, D2, . . .・・・・・・
,D? ), measurement data storage means (14) that captures magnetic signals from these magnetic detectors at a predetermined period and stores them for each magnetic detector; The coils (La, L
b), means (ST7 to 5TIO) for calculating the magnetism due only to the coil at the coil passing position based on the magnetic detector output when the coil is energized and the measurement data when the coil is not energized; maximum value position extraction means (STII) for extracting the position of the maximum value of the direction component perpendicular to the column line;
azimuth calculating means (ST12) for calculating the azimuth of the passing object based on the direction component perpendicular to the column line and the parallel direction component output of the magnetic detector closest to the extracted maximum value position; Magnetic moment calculation means (ST13
), and a means (ST14) for calculating a magnetic signal at the position where the vehicle would originally pass from the obtained magnetic moment.

In this passing body magnetism measurement device, when a ship passes through a row of magnetic detectors, the detection output of each magnetic detector is stored in a storage means at a predetermined sampling period, as in the conventional case. . Further, when the position of the coil provided on the ship passes through the arrangement line, the coil is energized. Then, based on the magnetic detector output when the coil is energized and the measurement data when it is not energized, the hull magnetism at the coil passing position is calculated. Then, the position of the maximum value of the directional component (X component) perpendicular to the column line of this hull magnetism is extracted. The position of this maximum value is the position where the ship actually passed. Next, the direction component perpendicular to the column line of the output of the magnetic detector closest to this maximum value position,
The direction of the vehicle is determined from the direction component parallel to the row line.

And the direction you sought.

A magnetic moment is calculated from the position and the magnetic signal, and from this magnetic moment a corrected magnetic signal at the direction and position of the planned passage is obtained.

(E) Examples The present invention will be explained in more detail with reference to Examples below.

FIG. 2 is a block diagram of a ship magnetism measuring device in which the present invention is implemented. In the same figure, the magnetic detector ri, D2
, . . . , D7 are arranged on the seabed in rows at predetermined intervals, just like the one shown in FIG. These magnetic detectors D1, Dz..., D7 are connected to the main device 10, and are sent to the CPU 13 at a predetermined sampling period via the receiving section 11 and input/output section 12 of the main device 10.
The data is taken in and stored in the storage device 14.

In addition, the main device 10 includes a display 15 for displaying measurement results, and an interrupt signal generator 16 for inputting "start", "end", "loop signals", etc., which will be described later.

In addition, the main unit 10 and the magnetic detector D1. D2...
..., D7 have the positional relationship shown in Fig. 3, and are located in the measurement chamber 30 installed on land on the line where the magnetic detectors 8, D2, ..., D, are arranged. , a main body device 10 is provided. Note that there are coils La,
Lb is wound. However, this coil La, L
b also serves as a coil provided for magnetic cancellation. These coils La and Lb are respectively magnetic detectors D1
．． A visual mark is placed on the ship 2 so that it can be confirmed from the monitoring point 31 in the measurement room 30 when it reaches the line where D2, . . . , D7 are arranged.

Next, the soft groove formation and operation of the ship body magnetism measuring device according to the above embodiment will be explained with reference to the flowchart shown in FIG.

When the device is powered on, it is first determined whether a start signal is present (step 5TI). If the vessel 2 to be measured does not exist in the measurement area, the "start" button of the interrupt signal generating section 16 is not pressed, and therefore the determination is NO and the vessel is on standby.

Eventually, the ship under test 2 enters the measurement area, the measurer confirms the entrance of the ship under test 2, and the interrupt signal generator 16
When you press the "Start" button, the judgment of step STI is YES.
Then, each magnetic detector D1D2,...
The output of D is read and stored in the storage device 14 for each magnetic detector as shown in FIG. 5 (step ST2.5).
T3). Subsequently, it is determined whether or not there is an interrupt signal (step 5T4).

Unless an interrupt signal such as an end signal or a loop signal is input, this determination will be No, and the process will return to step ST2. From then on, the processing of steps ST2 to ST4 will be repeated until an interrupt signal is input, and the time interval (sampling period > TI At each time, measurement data from each magnetic detector D1, D2, . . . , D7 is stored.

As the ship 2 moves forward, the coil La is detected by the magnetic detector D1. D2,...,D.

When it is confirmed that the measurement line has arrived at the arrangement line, the measurer presses the "loop signal" button of the interrupt signal generation section 16. In response to this, the interrupt signal generating section 16 outputs a loop signal. Therefore, in step ST4 “
The determination of ``Is there an interrupt signal?'' is YES, and the determination of ``Is there an end signal?'' of step ST5 is NO, and then it is determined whether it is the first loop signal (ST knob 5T6). In this case, this determination is YES.
At this time, each key output of the magnetic detectors DI, D2,..., D, is H, I, H21,..., H7I.
(Step 5T7). In addition, when the "loop signal" button is pressed, the coil La is energized, so the magnetic signals H, I, H2I, ......, H, I
is a combination of the hull magnetism and the magnetism caused by the coil La.

Following step ST7, the process returns to step ST2, where each magnetic detector D1 . The detection outputs of D2, . . . , D7 are read and stored (step ST2.5T3). in this case,
Of course, the current supply to the coil La is stopped.

The ship 2 moves further, and the coil Lb becomes a magnetic detector 5.
When it is confirmed that the line D2, . A loop signal is output from 16. Therefore, step ST4
YES in step ST5, NO in step ST5, and then it is determined whether or not it is the first loop signal (step 5T).
6). Since the loop signal from the coil Lb is the second loop signal, this determination is NO. At this time, the magnetic detector D1. Each detection output of D2,...,D, is H,! ', H21', . . . , H7I' (step 5T8). In this case as well, the coil Lb is energized, so the magnetic signals H, l', H2I'
. . . H7 Bi is a combination of hull magnetism and coil Lb magnetism.

Following step ST8, the process returns to step ST2, and until the next interrupt occurs, the detection outputs of each magnetic detector 3, D2, . . . , D are read at time intervals T, Store (step ST2.5T3). Also in this case, of course, the energization of the coil Lb is stopped.

When the ship 2 moves further and goes out of the measurement area, the f
l'fl The operator who performed the LW inputs the interrupt signal generator 16's
Press the “Finish” button. As a result, the interrupt signal generator 16
A termination signal is output from. Therefore, step ST4
The determination in step ST5 is YES, and the process then moves to step ST9, where the next calculation is performed.

Hn (I+1)+Hn (1-1) = Hn' (1) Equation (1) is based on the relationship between each magnetic detector D1. D2...
, the average value Hn' of the magnetic output of D7 (n = 1 to 7)
, (Equation 21 is the average value Hm' of the magnetic output of each magnetic detector D1, D2, ..., D7 before and after the coil Lb reaches the same arrangement line, and if the coil La ,Lb
corresponds to the hull magnetism that would be obtained if no current was applied to each.

Subsequently, the process moves to step 5TIO, and the next calculation is performed.

Hn I-Hn' = Hn" ... (3) Hnl
'-Hm' = Hm" -... (4) Equation (3) is
From the magnetic signal Hnl when the coil La is energized, the value obtained by eliminating the hull magnetism Hn'' that would be obtained when the coil La is not energized, that is, the magnetic output Hn+ ゛ by the coil La, is calculated from the magnetic signal Hnl when the coil La is energized. This is a formula for determining the value obtained by subtracting the hull magnetism Hm'' that would be obtained when no current is applied from the magnetic signal HnI'', that is, the magnetic output Hm''' from the coil Lb.

Next, H n ” (H+
",Hz",...,H7"),Hm"
For the X component (component in the direction perpendicular to the installation side line) of (H1") Hz", "'"',H7"), extract the position of the maximum value. Then, find the average value of that position. Now Assuming that the ship 2 passes over the magnetic detector D4 at right angles, the distribution of the X component generated by the coil has a maximum value at the point of the magnetic detector D4, as shown in FIG.

In other words, the point with the maximum value is the position through which the ship has passed.

If the ship 2 approaches the arrangement line at an angle θ rather than perpendicular to the arrangement line, the positions where the maximum value occurs will be at different points, so the average is taken.

Following step 5TII, the magnetic detector closest to the determined position is extracted. Then, the magnetic output of the component (X component) in the direction perpendicular to the array line of the magnetic detector is Hx, and the magnetic output of the component (X component) in the parallel direction to the array line of the magnetic detector is Hy. Calculate the azimuth angle θ. Coil La, Lb
Since θa1θb is calculated for
The azimuth angle θ is determined (step 5T12).

With the above processing, the bearing, position, and magnetic signal of the ship to be measured have been obtained, and as a function of these, the magnetic moment is calculated by the method of least squares (step 5T13). Therefore, due to this magnetic moment, the ship 2 is oriented in its original direction.
Calculate and correct the magnetic signal generated when passing the position (
Step 5T14).

Here, the processing of steps 5T13 and 5T14 will be slightly modified with reference to FIG.

Now, focusing on one magnetic detector, in relation to the hull 2 at a certain point in time, the distance X shown in Fig. 7<a)
, Y is known, then, however, in Fig. 7 (b
HxXHy as shown in l.

Hz is the axial component of the magnetic detector, and Hx', Hy', and Hz' are the magnetic fields in the bow and stern direction.

However, the magnetic field ■1 is H=F (Mx, My, Mz, X, Y, Z) -- (
61.

To the above equation (6), apply the value of (5) 2 to an arbitrary number of points, and use the least squares method to calculate the magnetic moments Mx, My, M
Find z. Then, the magnetic moment I-Mx, M
From y, Mz and an arbitrary position (X, Y), the magnetic field value at each position is calculated using equation (6). In other words, the magnetic field value at the position where the ship originally passes is calculated.

(f) Effects of the Invention According to this invention, by providing a coil on a ship, for example by using a demagnetizing coil, the direction and position of a passing object such as a ship can be measured, and based on this direction and position. Since it is possible to correct the magnetic distribution, it is possible to measure the magnetic distribution with high accuracy. Furthermore, there is no need to equip the ship with a rangefinder or the like to measure the route, and this can be achieved at low cost.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a flow diagram for explaining the software configuration and operation of a ship magnetism measurement device in which the present invention is implemented, and Fig. 2 is a block diagram of the ship magnetism measurement device. Figure 3 shows the positional relationship between the magnetic detector and the measurement chamber of the device, and Figure 4 shows the
FIG. 5 is a diagram showing the distribution of components perpendicular to the direction of the array line of magnetic detectors arranged by the coil. FIG. 5 is a diagram illustrating the data storage contents of the storage device. FIG. Plan view and side view showing the arrangement of the detector, Fig. 7(a) (
b) is an explanatory diagram for explaining magnetic moment calculation and magnetic signal correction processing in the flowchart of FIG. 1; D,・D2...D,;Magnetic detector, 13:
CPU, 14: Storage device, 16: Interrupt signal generation section. Patent applicant: Shimadzu Corporation Agent
Patent Attorney Shigeru Nakamura Figure 1 Figure 6 Da Figure 3 Kaya 7 Hi

Claims (1)

[Claims] (1) A plurality of magnetic detectors arranged in a line at predetermined intervals on the seabed, and a measurement data storage means that captures magnetic signals from these magnetic detectors at a predetermined period and stores them for each magnetic detector. , a coil that is provided on the vehicle and is energized when it reaches the position of the magnetic detector during the vehicle, and a coil passing position based on the magnetic detector output when the coil is energized and the measurement data when it is not energized. means for calculating the magnetism due only to the coil; maximum position extracting means for extracting the position of the maximum value of the direction component perpendicular to the column line of the calculated magnetism; and a magnetic detection unit nearest to the extracted maximum value position. azimuth calculating means for calculating the azimuth of the passing vehicle based on the directional component output perpendicular to the column line and the parallel directional component output of the device;
A vehicle consisting of a magnetic moment calculation means for calculating the magnetic moment of the vehicle based on the position and magnetic signal, and a means for calculating a magnetic signal at the position where the vehicle originally passes from the calculated magnetic moment. Magnetic measuring device.