JPH09159454A - Electronic direction detection apparatus for moving body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic direction detection apparatus by which an indication error is reducid sufficienly as compared with that in conventional cases and in which the complicated adjusting operation of a magnetic sensitivity as in conventional cases is not required. SOLUTION: An electronic direction meter which is used as an apparatus is constituted in such a way that a direction sensor 11 provided with a ring- shaped toroidal core 12 on which an exciting winding 13 is wound, with an inside coil which is wound in the radial direction across opposite parts 12a, 12b on one side at the core 12 and with an outside coil 15 which is wound from the upper part of the inside coil 13 at right angles to the inside coil across opposite parts 12c, 12d which are displaced by 90 deg. from the opposite parts 12a, 12b on one side at the core 12 is attached to a vehicle body 10. In this case, the detection direction of the magnetic flux of the inside coil is directed in a direction in which the magnetic sensitivity of the vehicle body 10 is low, and the detection direction of the magnetic flux of the outside coil 15 is directed in a direction in which the magnetic sensitivity of the vehicle body 10 is high.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic azimuth detecting device for a mobile body, which is mounted on the mobile body to measure the moving direction of the mobile body by detecting the geomagnetism.

[0002]

2. Description of the Related Art As an electronic azimuth detecting device for a moving body of this type, as shown in FIG.
Gazette), an annular toroidal core 1 which is a magnetic body around which an excitation winding (not shown) is wound, and an inner coil which is wound in a diametrical direction between the facing portions 1a and 1b of the annular toroidal core 1. (First winding) 2 and the annular toroidal core 1
Of the facing portions 1a and 1b, which are offset by 90 degrees from each other,
The inner coil 2 is orthogonal to the inner coil 2 during 1d.
A geomagnetic detection type azimuth sensor (that is, a fluxgate sensor (electronic azimuth meter)) including an outer coil 3 (second winding) wound from above is considered.

In this direction sensor, when the excitation winding is AC-excited, the magnetic fluxes Φ1 and Φ2 passing through the facing portions 1a and 1b of the annular toroidal core 1 are equal in size and opposite in direction, so that they are output windings. The interlinkage magnetic flux of the coil 2 becomes zero and the output voltage V1 is not generated. Similarly, the output voltage V2 is not generated in the outer coil 3 either.

Next, when the earth magnetic field He is applied to the inner coil 2 from the right angle direction, the magnetic fluxes Φ1 and Φ2 become asymmetric, and the output voltage V1 is generated in the inner coil 2. At this time, since the earth magnetic field He does not interlink with the outer coil 3, the output voltage V2 is not generated.

When a vehicle such as an automobile is equipped with such a direction sensor, the traveling direction θ of the vehicle can be expressed by θ = tan-1 (V1 / V2). In this way, the traveling direction of a vehicle such as an automobile is measured.

[0006]

However, in the direction sensor as described above, the inner coil 2 and the outer coil 3 have the same wire diameter, and the outer coil 3 is the inner coil 2.
Since the coils are wound from above, the outer coil 3 is slightly farther than the inner coil 2 with respect to the annular toroidal core 1 when the two coils 2 and 3 have the same number of turns. As a result, the inner coil has a higher sensitivity and a difference in sensitivity occurs.

If there is a difference in sensitivity between the inner coil 2 and the outer coil 3 in this way, a finger pointing error occurs.

Therefore, in order to correct such an error,
Conventionally, the magnetic detection sensitivity is adjusted by adjusting the amplification degree of the amplifier that amplifies the outputs of the coils 2 and 3, but the adjustment work is very complicated.

Therefore, an object of the present invention is to provide an electronic azimuth detecting apparatus for a moving body in which finger error is sufficiently reduced as compared with the conventional one, and which does not require a complicated magnetic sensitivity adjusting work as in the conventional one. It is what

[0010]

To achieve this object, the present invention provides an annular magnetic body around which an excitation winding is wound,
A first winding wound in a diametrical direction between one facing portion of the annular magnetic body and a first winding orthogonal to the one facing portion of the annular magnetic body that is offset by 90 degrees from the one facing portion. An electronic azimuth detecting device for a moving body, wherein an azimuth sensor comprising a first winding number and a second winding number having the same number of turns on the first winding is attached to a moving body, wherein a magnetic flux of the first winding is detected. An electronic azimuth detecting device for a mobile body, the direction of which is directed to a direction where the magnetic sensitivity of the mobile body is low, and the magnetic flux detection direction of the second winding is directed to a direction where the magnetic sensitivity of the mobile body is high. It is characterized by having done.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS.

In FIGS. 1 (a) and 1 (c), 10 is a vehicle body of an automobile (vehicle) which is a moving body, and 11 is a geomagnetic detection type direction sensor mounted on the vehicle body 10.

As shown in FIGS. 1 and 2, the orientation sensor 11 (that is, the fluxgate sensor) is wound around an annular toroidal core (annular magnetic body) 12 and an annular toroidal core 12, which are ferromagnetic materials. Excitation winding 13, inner coil (first winding) 14 wound in a diametrical direction between facing portions 12a, 12b of annular toroidal core 12, and 90 ° offset from facing portion 12a, 12b of annular toroidal core 12 The outer coil (second winding) 15 wound on the inner coil 14 orthogonal to the inner coil 14 between the facing portions 12c and 12d.
Having. The coils 14 and 15 have the same wire diameter, and the coils 14 and 15 are wound around the annular toroidal core 12 the same number of times.

Further, the excitation winding 13 of the direction sensor 11
Is excited by an alternating current by an exciting circuit 16, and an output V1 of the coil 14 and an output V2 of the coil 15 are respectively amplified by amplifiers 17 and 18 and input to a display control circuit 19. Moreover, the display 20 is connected to the output side of the display control circuit 19. In addition, the amplifier 17,
18 is set to the same amplification degree.

By the way, the inner coil 14 and the outer coil 1
Since the wire diameters of 5 are the same, the outer coil 15 is wound from above the inner coil 14. Moreover, since the number of turns of both coils 14 and 15 is set to be the same, the outer coil 15 is slightly farther from the inner toroidal core 12 than the inner coil 14, so that the inner coil is more sensitive. Becomes higher, resulting in a difference in sensitivity. If there is a difference in sensitivity between the inner coil 14 and the outer coil 15 as described above, a finger pointing error occurs.

As a result, in the state where the orientation sensor 11 is not mounted on the vehicle body 10, the detection sensitivity Ya in the magnetic flux detection direction of the inner coil 14 (the direction orthogonal to the inner coil 14) is shown in FIG. ), The detection sensitivity is higher by 10 to 25% than the detection sensitivity Xa of the outer coil 15 in the magnetic flux detection direction (direction orthogonal to the outer coil 15) X.

On the other hand, in a moving body such as an automobile, most of the vehicle body 10 is formed of iron, and the front-rear length and the left-right length ratio of the vehicle body 10 are different. 1A is longer than the length in the vehicle width direction, the magnetic sensitivity A in the front-back direction of the vehicle body 10 (ease of collecting magnetic flux) A is the magnetic sensitivity B in the vehicle width direction as shown in FIG. Higher than.

Therefore, when the azimuth sensor 11 is mounted on the vehicle body 10, the azimuth sensor 11 is arranged by directing the magnetic flux detection direction Y in the vehicle width direction of the vehicle body 10 and the magnetic flux detection direction X in the front-back direction of the vehicle body 10. The detection sensitivities Xa and Ya in the magnetic flux detection directions X and Y can be made substantially equal as shown in FIG.

As a result, in the direction sensor 11 described above, when the exciting winding 13 is AC-excited by the alternating current from the exciting circuit 16, the opposing portions 12a, 12b of the annular toroidal core 12 are excited.
Since the magnetic fluxes Φ1 and Φ2 passing through are equal in magnitude and opposite in direction, the interlinkage magnetic flux of the inner coil 14 which is the output winding becomes zero and the output voltage V1 is not generated. Similarly, the output voltage V2 is not generated in the outer coil 15, either. Next, when the earth magnetic field He is applied to the inner coil 14 from the right angle direction, the magnetic fluxes Φ1 and Φ2 become asymmetric, and the output voltage V1 is generated in the inner coil 14. At this time, since the earth magnetic field He does not interlink with the outer coil 15, the output voltage V2 is not generated.

Therefore, the traveling direction θ of the vehicle can be expressed by θ = tan-1 (V1 / V2) ... (1). In this way, the traveling direction of a vehicle such as an automobile is measured.

The output voltage V of the coils 14 and 15
1, V2 are amplified by the amplifiers 17 and 18 and input to the display control circuit 19. This display control circuit 19 is (1)
The moving direction θ of the vehicle is obtained from the expression, and the moving direction θ of the vehicle is displayed on the display unit 20 by the direction of the vehicle body 10 or the arrow. It is desirable that the orientation sensor be mounted on the vehicle at a location where the vehicle body is not easily magnetized, that is, the central portion of the vehicle where the magnetic flux is constant (parallel).

[0022]

As described above, the present invention includes the annular magnetic body around which the excitation winding is wound, and the first winding wound diametrically between the opposing portions of the annular magnetic body. , The first portion between the facing portions of the annular magnetic body that are offset by 90 degrees from the facing portion.
An electronic azimuth meter in which a moving body is equipped with an azimuth sensor comprising a first winding and a second winding having the same number of turns on the first winding orthogonal to the winding. Since the magnetic flux detection direction of is directed to the direction in which the magnetic sensitivity of the moving body is low, and the magnetic flux detection direction of the second winding is directed to the direction in which the magnetic sensitivity of the moving body is high,
It is possible to sufficiently reduce the finger pointing error as compared with the conventional technique, and to eliminate the complicated magnetic sensitivity adjustment work as in the conventional technique.

[Brief description of the drawings]

1A is an explanatory diagram showing a magnetic sensitivity characteristic of a vehicle, FIG. 1B is an explanatory diagram of an electronic orientation sensor, and FIG. 1C is a vehicle of FIG. 1A in which the orientation sensor of FIG. FIG.

FIG. 2 is a control circuit diagram of the orientation sensor shown in FIG. 1 (b).

FIG. 3 is an explanatory diagram of a conventional orientation sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Vehicle body (moving body) 11 ... Direction sensor 12 ... Annular toroidal core (annular magnetic material) 12a, 12b ... One opposing part 12c, 12d ... Opposing part 13 ... Excitation winding 14 ... Inner coil (first winding) 15 ... Outer coil (second winding)

Claims (1)

[Claims] 1. An annular magnetic body around which an excitation winding is wound, and a first diametrically wound portion between opposite portions of the annular magnetic body.
A second winding, which is orthogonal to the first winding and is wound on the first winding by the same number of turns as the first winding between the winding and the facing portion of the annular magnetic body that is offset by 90 degrees from the one facing portion. In a moving body electronic azimuth detecting device in which a direction sensor including a winding is attached to a moving body, the magnetic flux detection direction of the first winding is directed to a direction in which the magnetic sensitivity of the moving body is low, and An electronic azimuth detecting device for a mobile body, wherein a magnetic flux detecting direction of the second winding is directed to a direction in which the magnetic sensitivity of the mobile body is high.