JPH0749240A - Magnetic deviation correction device for magnetic compass - Google Patents

Abstract

PURPOSE:To increase the accuracy of a bearing signal by using a gyro compass as a magnetic compass in common. CONSTITUTION:In a normal case, an arithmetic circuit 33 finds a differential signal DELTA between a bearing signal alpha inputted from a magnetic compass 1 via a magnetic compass signal input circuit 31, and a bearing signal beta inputted from a gyro compass 2 via gyro compass signal input circuit 32. Then, the circuit 33 stores the differential signal DELTA together with the bearing signal alphaAt the same time, the circuit 33 outputs the bearing signal beta as a bearing signal gammashowing a correct bearing to a display device 35. If the bearing signal betais lost due to the failure of the gyro compass 2 or the like, the circuit 33 superposes the signal DELTA corresponding to the bearing signal alpha stored in a memory circuit 34 thereon, and outputs the superposed signal as a bearing signal gammashowing a correct bearing to the display device 35.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic compass difference correction device applied to a bow direction indicator of a ship.

[0002]

2. Description of the Related Art Conventionally, the pointing power of a magnetic compass has been used directly to indicate the direction of a ship or the like. With this magnetic compass,
The direction of the bow is obtained by using the geomagnetism. In addition to this, a highly accurate gyro compass or the like is also used to indicate the direction of a ship or the like.

[0003]

As described above, in the magnetic compass, since the orientation of the bow is obtained by utilizing the geomagnetism, magnetic influences such as the structure of the hull which is a magnetic body cannot be avoided. In addition, the magnetic compass is less accurate than the gyro compass, so there was a problem in its operation as a precise navigation instrument.

On the other hand, the gyro compass does not operate when the AC power is lost, and may have a failure because it has a rotating mechanism. Therefore, it is necessary to prepare a spare gyro compass as a backup.

The present invention has been made in consideration of the above circumstances, and an object thereof is to use a gyro compass in combination with a magnetic compass to correct an azimuth signal obtained by the magnetic compass, thereby improving the terrestrial magnetism and the like. It is an object of the present invention to provide a magnetic compass difference correction device that can obtain a highly accurate azimuth signal even if it is affected.

[0006]

The present invention is directed to a magnetic compass direction signal input means for inputting a magnetic compass direction signal indicating the direction measured by a magnetic compass, and a gyro compass direction signal indicating the direction measured by a gyro compass. Gyro compass azimuth signal input means for inputting, a calculating means for obtaining a difference signal between the magnetic compass azimuth signal and the gyro compass azimuth signal, and for storing the difference signal obtained by this calculating means together with the corresponding magnetic compass azimuth signal When the gyro compass azimuth signal is lost, the computing means stores the magnetic compass azimuth signal input by the magnetic compass azimuth signal input means stored in the storage means. A modified azimuth signal that superimposes the difference signal corresponding to the azimuth signal is output to the display device. And wherein the door.

[0007]

In the above structure, when the magnetic compass direction signal is input from the magnetic compass through the magnetic compass direction signal input means and the gyro compass direction signal is input from the gyro compass through the gyro compass direction signal input means, The difference signal between the magnetic compass direction signal and the gyro compass direction signal is calculated by the calculating means. The calculated difference signal is stored in the storage means together with the magnetic compass direction signal at that time.

When the gyro compass direction signal is lost due to a failure of the gyro compass or the like, the difference signal corresponding to the direction signal stored in the storage means is superimposed on the magnetic compass direction signal by the calculating means. The magnetic compass azimuth signal on which the difference signal is superimposed is output to the display device by the calculating means as an azimuth signal indicating the correct azimuth.

As described above, the error of the magnetic compass direction signal is corrected by superimposing the difference signal between the magnetic compass direction signal and the gyro compass direction signal, which is obtained in advance, on the magnetic compass direction signal. Even if a magnetic compass is used, a highly accurate azimuth signal can be obtained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the magnetic compass difference correction device according to the embodiment.

In FIG. 1, the magnetic compass difference correction device 3 comprises a magnetic compass signal input circuit 31, a gyro compass signal input circuit 32, an arithmetic circuit 33, a memory circuit 34, and a display device 35. The magnetic compass signal input circuit 31, the gyro compass signal input circuit 32, the memory circuit 34, and the display device 35 are respectively provided in the arithmetic circuit 3.
Connected to 3.

The magnetic compass signal input circuit 31 inputs an azimuth signal indicating the azimuth measured by the magnetic compass 1 connected to the signal input circuit 31 to the arithmetic circuit 33. The gyro compass signal input circuit 32 is the same as the signal input circuit 3
The azimuth signal indicating the azimuth measured by the gyro compass 2 connected to the No. 2 is input to the arithmetic circuit 33.

The arithmetic circuit 33 calculates a difference signal between the azimuth signal input from the magnetic compass signal input circuit 31 and the azimuth signal input from the gyro compass signal input circuit 32.

In the storage circuit 34, the difference signal calculated by the calculation circuit 33 is recorded together with the azimuth signal from the magnetic compass signal input circuit 31 corresponding to the difference signal. Display device 3
5 outputs the calculation result in the calculation circuit 33 in a visible form.

Next, the operation of the magnetic compass difference correction device having the above-mentioned structure when the device is applied to a ship will be described. Here, the azimuth signal output from the magnetic compass 1 is α, and the azimuth signal output from the gyro compass 2 is β.

The minimum unit of the azimuth signal α and the azimuth signal β is 0.1 °, and the values of the azimuth signal α and the azimuth signal β of 0.1 ° or less are rounded off.

First, the azimuth signal α from the magnetic compass 1
Is the arithmetic circuit 3 via the magnetic compass signal input circuit 31.
Input to 3. On the other hand, the azimuth signal β from the gyro compass 2 is input to the arithmetic circuit 33 via the gyro compass signal input circuit 32.

Then, the arithmetic circuit 33 first obtains a difference signal Δ = β-α between the azimuth signal α input from the magnetic compass signal input circuit 31 and the azimuth signal β input from the gyro compass signal input circuit 32. . Next, the arithmetic circuit 3
3 stores the obtained difference signal Δ together with the azimuth signal α in the storage circuit 34.
Remember. This difference signal Δ is constantly calculated by the arithmetic circuit 33 as long as the direction signals α and β are input, so that the difference signal Δ corresponding to the input signal α is constantly rewritten in the memory circuit 34.

Here, in a normal case, that is, when the gyro compass 2 is normal, the arithmetic circuit 33 uses the azimuth signal γ (indicating the correct azimuth as the azimuth signal β input from the gyro compass signal input circuit 32). γ = β) is output to the display device 35. Therefore, the display device 3
In 5, the finger index of the gyro compass 2 is displayed as it is.

On the other hand, if the gyro compass direction signal β is lost due to a failure of the gyro compass 2, loss of AC power, or the like, the arithmetic circuit 33 is first input through the magnetic compass signal input circuit 31. Magnetic compass 1
The difference signal Δ corresponding to the azimuth signal α is read from the storage circuit 34. Next, the arithmetic circuit 33 superimposes (α + Δ) the read difference signal Δ on the azimuth signal α. Thereby, the error of the magnetic compass direction signal α is corrected. Next, the arithmetic circuit 33 outputs the error correction result to the azimuth signal γ [γ = α + Δ = α + (β−α) = β] indicating the correct azimuth.
Is output to the display device 35. Therefore, on the display device 35, the one in which the error of the finger index of the magnetic compass 1 is corrected is displayed.

[0021] Here, the ship makes one revolution, and all directions (360
In the case where the difference signal Δ for (°) is stored in the memory circuit 34, if the direction signal β is lost, the corresponding difference signal Δ in the memory circuit 34 is superimposed on the direction signal α from the magnetic compass 1. If the bearing signal β is lost before the difference signals Δ for all bearings are stored, the bearing signal α for which the difference signal Δ has not been calculated is processed as the difference signal Δ = 0.

As described above, in the above-described embodiment, normally, the difference signal Δ between the azimuth signal β of the gyro compass 2 and the azimuth signal α of the magnetic compass 1 having a high accuracy is always obtained, and the obtained difference signal Δ is corresponded. It is stored together with the azimuth signal α.
Gyro compass 2 malfunction, or gyro compass 2
When the magnetic compass 1 is used due to the loss of the AC power supply necessary for operating the compass, the difference signal Δ corresponding to the azimuth signal α from the magnetic compass 1 stored in advance is superimposed on the azimuth signal α. Then, the direction signal α of the magnetic compass 1
The error of is corrected. Therefore, even if the magnetic compass 1 is used, a highly accurate direction signal can be obtained.

[0023]

According to the present invention, in the case of a normal track, a difference signal between the azimuth signal of the gyro compass and the azimuth signal of the magnetic compass is obtained, and the difference signal is recorded together with the azimuth signal of the magnetic compass corresponding to the same signal. A gyro compass direction signal with high accuracy is used as the direction signal to be stored and actually used. If the gyro compass fails or the AC power is lost, the direction signal of this magnetic compass is included in the direction signal of the magnetic compass and the difference signal (error signal) from the direction signal of the gyro compass that has been stored so far. The difference signal corresponding to is superimposed to correct the error of the direction signal of the magnetic compass. Therefore, according to the present invention, a highly accurate azimuth signal can be obtained even if a magnetic compass is used.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a magnetic compass magnetic difference correction device according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetic compass, 2 ... Gyro compass, 3 ... Magnetic compass difference correction device, 31 ... Magnetic compass signal input circuit, 32 ... Gyro compass signal input circuit, 33 ... Arithmetic circuit, 34 ... Storage circuit,
35 ... Display device.

Claims (1)

[Claims] 1. A display device, a magnetic compass direction signal input means for inputting a magnetic compass direction signal indicating a direction measured by a magnetic compass, and a gyro for inputting a gyro compass direction signal indicating a direction measured by a gyro compass. Compass azimuth signal input means, computing means for obtaining a difference signal between the magnetic compass azimuth signal input by the magnetic compass azimuth signal input means and the gyro compass azimuth signal input by the gyro compass azimuth signal input means And a storage unit for storing the difference signal obtained by the calculation unit together with the corresponding magnetic compass direction signal, and when the gyro compass direction signal is lost, the calculation unit includes the magnetic compass. The magnetic compass direction signal input by the direction signal input means Magnetic compass 磁差 adjustment device also outputs a correction azimuth signal superimposed a difference signal corresponding to the orientation signal stored in the serial storage unit on the display device.