JPS63159711A - Disturbance correcting method for goniometer - Google Patents

Abstract

PURPOSE:To perform accurate azimuth detection by an easy method by correcting a rotary error occurring to a magnet rotor owing to a disturbing magnetic field applied to an earth magnetism detecting part arranged outside a traveling body with a gravitational force operating on a weight arranged at a display part. CONSTITUTION:The rotational angle of the magnet roller 53 of a crossing coil type display 5 is determined by magnetic flux produced according to the direction of earth magnetism sent out of an earth magnetism azimuth angle sensor 1. A detection direction is displayed according to the rotational angle. Here, the disturbing magnetic field is affected by the deflection of the earth magnetism due to a difference in magnetic permeability and automobile body magnetism because of the extension arrangement of the sensor 1 outside the vehicle, and determined by the up/down position of the antenna 2. Then the outputs of Hall elements 12 and 13 are positioned on a constant circumference to generate an error through the amplifying operation of a magnet disk 11. Here, the weight 58 is added to a disk 57 for the display and then a detection error is corrected by its gravitational force. Further, the sensor 1 is fitted by cars and the weight 58 is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a disturbance correction method for a direction meter suitable for being mounted on a vehicle.

[Conventional technology]

In recent years, this type of direction meter has been equipped with a magnetic direction sensor that sends out an output signal according to the geomagnetic direction, and a magnetic flux corresponding to the output signal sent out by this magnetic direction sensor is applied to the magnet rotor to control the rotation of the magnet rotor. A direction meter has been proposed that detects the geomagnetic direction using the angle.

Generally, this type of direction meter is mounted on a vehicle and is configured to provide direction information to the driver on its display section.

Generally, vehicles such as automobiles are made of magnetic material, and when passing through a railroad crossing or the like, the vehicle body becomes magnetized by the current flowing through the overhead wires and tracks. Further, when a vehicle moves through the earth's magnetic field, the earth's magnetic field passing through the vehicle is deflected due to the difference in magnetic permeability between the atmosphere and the vehicle. Therefore, an error may occur in the output of the magnetic azimuth sensor, that is, the rotation angle of the magnet rotor, and there is a possibility that measurement may become impossible.

As a method for correcting errors caused by magnetization of the vehicle body, declination of the earth's magnetic field, etc., a correction method using a computer is employed in conventional direction meters. Figure 6 shows the principle. In other words, when the vehicle rotates once in the magnetic field of the geomagnetic disturbance B1, the directions are N (north), E (east), and S (south).
, W (west) is N'.

It shows the directions of E, S', and W. Therefore, the direction and absolute value of the disturbance magnetic field B1 are calculated from the X-axis and Y-axis using a computer, and the coordinates are converted to the N'-axis and Y-axis to indicate accurate orientation. FIG. 7 is a block diagram showing an azimuth meter to which this correction method is applied.

[Problem that the invention seeks to solve]

However, according to such a conventional direction meter disturbance correction method, since a computer is used, there is a problem in that the cost of the correction system increases significantly.

[Means for solving problems]

The present invention has been made in view of these problems, and includes arranging the geomagnetism detecting section of the magnetic orientation sensor to extend outside the traveling body, and preventing the rotation generated in the magnet rotor by the disturbance magnetic field applied to the geomagnetism detecting section. The angular error is corrected by the gravity acting on the weight by disposing a weight on the display section.

[Effect]

Therefore, according to the present invention, the rotational angle error occurring in the magnet rotor is corrected by the gravity acting on the weight.

〔Example〕

Hereinafter, the direction meter disturbance correction method according to the present invention will be explained in detail. FIG. 1 is a circuit diagram showing an embodiment of the disturbance correction method for this compass. In the same figure, l is an azimuth angle detection sensor arranged on the external antenna (Fig. 2 (a) to (C1) 2 in the center of the rear of the vehicle so that its mounting position can be adjusted. The azimuth angle detection sensor 1 is , a magnetic disk 11 magnetized so that the strength of the magnetic field on its outer periphery is sinusoidal, and Hall elements 12 and 13 that are arranged opposite to each other on the outer peripheral surface of this magnetic disk 11 with a phase difference of 90°. Thus, the Hall elements 12 and 13 are supplied with a power supply voltage from the DC power supply 3. That is, the magnet disk 11 is pivotally supported so as to follow and rotate in the geomagnetic direction. The magnetic pole position of this magnet disk 11 is detected by Hall elements 12 and 13, and the magnetic pole position detection signals sent from these Hall elements 12 and 13 are directly input to subsequent stage amplifier circuits 41 and 42. .Then, these amplifier circuits 41 and 42
An amplified current corresponding to the magnetic pole position detection signal amplified in flows through the crossed coils 51 and 52 of the crossed coil type display 5, and by generating magnetic flux in the crossed coils 51 and 52 according to this amplified current, the magnet rotor The rotation angle of 53 is determined. That is, a magnet rotor 53 is rotatably supported in the magnetic field created by the intersecting coils 51 and 52, and based on the rotation angle of the magnet rotor 53, the magnet disk 1
The configuration is such that the geomagnetic field acting on the magnetic field is detected.

FIG. 3 shows a detailed configuration example of the cross-coil type display 5, in which 54 is a magnetic shield case;
5 is a crossed coil resin body, 56 is a magnet rotor 5
The indicator shaft 57 connected to 3 is a disc-shaped display desk whose center portion is fixed to the indicator shaft 56. A weight 58 for error correction is attached at a predetermined rotation angle position on the back side of the display desk 57. The cross-coil type display 5 configured in this manner is used by being arranged so that gravity acts on the weight 58 from the direction of arrow A in the figure.

In FIG. 1, reference numeral 6 denotes a D/D converter, which is configured to receive the DC voltage from the DC power supply 3 as an input and generate positive and negative DC voltages from its output terminals 61 and 62. There is. In addition, Fig. 2 (a) and (b)
) shows the declination state due to the difference in permeability of the earth's magnetic field acting on the vehicle, and FIG. 2 tc) shows the state of the magnetic field of the vehicle due to magnetization.

Next, the operation of the compass thus constructed will be explained with reference to FIGS. 4 and 5. That is, FIG. 4 is a vector diagram showing the magnetic field applied to the azimuth angle detection sensor 1 mounted on the antenna 2, and in the figure, H is a geomagnetic vector and B is a disturbance vector. Here, the absolute value of the disturbance vector B is influenced by the declination of the earth's magnetic field due to the difference in magnetic permeability and by the vehicle body magnetization because the azimuth angle detection sensor 1 is arranged to extend outside the vehicle. ,
It is determined by the vertical position of the azimuth detection sensor 1 on the antenna 2. FIG. 5 shows magnetic pole position detection signals output from the Hall elements 12 and 13 in response to the magnetic field shown in FIG.

What should be noted here is that due to the amplification effect of the magnetic disk 11, the outputs of the Hall elements 12 and 13 are not deformed such that the base axes are shifted as shown in FIG. This is to cause an error in the state. Therefore, in the case where the weight 58 is not attached, the outputs of the Hall elements 12 and 13 are displayed on the crossed coil display 5 at the same angle. now,
Position of W in FIG. 5 of display desk 57/
.

Assuming that a weight 58 of mass m is added to rotate W with W, the cosine component mg cos θ1 of gravity acting on this weight 58 and the error rotational force component due to the disturbance vector B will be balanced. . In other words,
The gravity acting on the weight 58 corrects the W' force direction detection error. The correction for this error is E'
Also in the direction, the mg cos θ component is zero, so correction by the weight 58 is not performed. Furthermore, even in directions other than these four poles (-5, N', S)'(NW',NE', s w', S E', etc.), the error that occurs at that time is the weight This will be approximately corrected by the cosine component mgcosθ of the gravity acting on 58.

In reality, the value of the disturbance vector B changes depending on the maximum total magnetic flux amount when magnetized and the total mass of the magnetic body depending on the vehicle type, but the value of the disturbance vector B changes depending on the vehicle type.
By selecting and adjusting the mounting height of the weight 58 and the mass of the weight 58, it is possible to respond appropriately, and the azimuth correction system is simplified (simplified) compared to the past, making it possible to significantly reduce the cost. Become.

〔Effect of the invention〕

As explained above, according to the disturbance correction method for a direction meter according to the present invention, the geomagnetism detection part of the magnetic direction sensor is arranged to extend outside the traveling body, and the disturbance magnetic field applied to the geomagnetism detection part generates in the magnet rotor. Since the rotation angle error is corrected by the gravity acting on the weight by placing a weight on the display '4,
Therefore, it becomes possible to detect the accurate direction using a simple method, and the cost can be reduced compared to the conventional method.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing an embodiment of the direction meter disturbance correction method according to the present invention, and Fig. 2 (a), (b) and (C)
Figure 3 is a plan view and side view showing the declination state of the earth's magnetism acting on a vehicle equipped with this compass and the magnetic field due to vehicle body magnetization, and Figure 3 is a side cross-section showing details of the cross-coil type display that makes up this compass. Figure 4 is a vector diagram showing the magnetic field applied to the azimuth detection sensor of this compass, Figure 5 is a diagram showing the magnetic pole position detection signal output from the Hall element in response to the magnetic field shown in Figure 4, FIG. 6 is an X-Y coordinate diagram of an operating magnetic field illustrating a conventional disturbance correction method for a compass, and FIG. 7 is a block diagram of a compass to which this compensation method is applied. DESCRIPTION OF SYMBOLS 1... Azimuth angle detection sensor, 11... Magnet disk, 12.13... Hall element, 2... External antenna, 5... Cross coil type display, 51.52...
・Cross coil, 53... Magnet rotor, 57...
・Display desk, 58... weight.

Claims (1)

[Claims] A display unit includes a magnetic orientation sensor that sends out an output signal according to the geomagnetic direction, and a magnetic rotor whose rotation angle is determined by a magnetic flux generated based on the output signal sent out from the magnetic orientation sensor. In this compass, the display unit displays a detected geomagnetic direction based on the rotation angle of the magnet rotor, in which a geomagnetic detection unit of the magnetic orientation sensor is arranged to extend outward from the traveling body, and the geomagnetic detection unit A direction meter characterized in that a rotation angle error caused in the magnet rotor due to a disturbance magnetic field applied to the display section is corrected by gravity acting on the weight by disposing a weight on the display section. Disturbance correction method