JPH11325904A - Earth magnetism azimuth sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an earth magnetism azimuth sensor wherein magnetic azimuth is automatically corrected to obtain a true azimuth even when latitude and longitude of a point which is to be measured is unknown. SOLUTION: An earth magnetism sensor 1, a tilt sensor 2, a corrective calculation part 32 wherein a tilt of magnetic output is corrected to be horizontal with altitude angle with inputted magnetic output detected by the earth magnetism sensor 1 and altitude angle detected by the tilt sensor 2, an azimuth calculation part 33 wherein a calculation result of the corrective calculation part 32 is inputted to calculate magnetic azimuth ψ, an antenna 4 which receives GPS signal transmitted from a GPS satellite, and a GPS receiver 5 wherein the GPS signal is inputted for outputting latitude/longitude information, are provided. Here, a deviation-angle calculation part 34 wherein the latitude/longitude information is inputted to calculate an angle of deviation δψ, and an adder part 35 wherein the magnetic azimuth ψ and the angle of deviation δψ are added together for outputting corrected through azimuth ψ' are comprised.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a geomagnetic azimuth sensor, and more particularly, to a geomagnetic azimuth sensor for automatically correcting a magnetic azimuth to obtain a true azimuth even if the longitude and latitude of a point to be measured are unknown. .

[0002]

2. Description of the Related Art A conventional example of a geomagnetic direction sensor will be specifically described with reference to FIG. In FIG. 3, reference numeral 1 denotes a geomagnetic sensor. The geomagnetic sensor 1 is composed of three components: a geomagnetic sensor X in a roll or X-axis direction, a pitci or a geomagnetic sensor Y in a Y-axis direction, and a yaw or a geomagnetic sensor Z in a Z-axis direction. _xtm is X detected by the geomagnetic sensor X
The axial magnetic output, _ytm indicates the Y-axis magnetic output detected by the geomagnetic sensor Y, and _ztm indicates the Z-axis magnetic output detected by the geomagnetic sensor Z.

[0003] Reference numeral 2 denotes an inclination sensor. This tilt sensor 2
Is the inclination sensor roll and the inclination sensor pitci.
People. φ is the roll detected by the tilt sensor roll
The 1-axis direction posture angle, θ indicates the pitci-axis direction posture angle detected by the tilt sensor pitci. Reference numeral 3 denotes an arithmetic processing unit. The arithmetic processing device 3 includes a computer 31 for performing arithmetic calculation processing in the device, a correction calculation unit 32 for calculating a rotation matrix, and an azimuth calculation unit 33 for inputting the calculation result of the correction calculation unit 32 and calculating a magnetic azimuth. Become. The correction calculator 32 includes an X-axis direction magnetic output x _tm , a Y-axis direction magnetic output y _tm and a Z-axis direction magnetic output z detected by the geomagnetic sensor 1.
_{In addition} to the input of _tm, the roll axis direction attitude angle φ and the pitci axis direction attitude angle θ detected by the tilt sensor 2 are input.

The above-described geomagnetic direction sensor has a correction calculation unit 3
2, the X-axis direction magnetic output x _tm , the Y-axis direction magnetic output y _tm and the Z-axis direction magnetic output z _tm detected by the geomagnetic sensor 1 are input, and the roll axis direction detected by the tilt sensor 2. The attitude angle φ and the attitude angle θ in the pitci-axis direction are input, and the rotation matrix is calculated here. As a result, the inclination of the magnetic output of the geomagnetic sensor 1 of the three orthogonal axes is corrected by the attitude angle detected by the inclination sensor 2, and is converted into data of the magnetic output that is horizontal and orthogonal.

[0005]

(Equation 1) The data corrected by the correction calculator 32 is input to the azimuth calculator 33, where the magnetic azimuth is calculated.

[0006]

(Equation 2) As described above, one data is divided by the other data, and the arctan of the division result is set to the magnetic direction ψ.

[0007]

Incidentally, magnetic north, ie, magnetic azimuth, and true north, ie, true azimuth, are generally not equal, and there is a deviation, ie, declination between them. And this declination shows a different value at each observation point on the earth. In other words, even if the magnetic azimuth shows the same measured value at each observation point on the earth, the argument is different at each observation point on the earth, so we want to know the direction at different points on the same basis In this case, it is necessary to indicate the true direction instead of the magnetic direction.

To obtain the true azimuth, first, the latitude and longitude of the measurement point are measured, the declination is calculated based on the measured values, and the magnetic azimuth is corrected based on the declination to obtain the true azimuth. It is necessary to do so, and the operation for finding the true direction is not always easy. The present invention provides a geomagnetic azimuth sensor that solves the above-described problem of automatically correcting a magnetic azimuth and finding a true azimuth even if the longitude and latitude of a point to be measured are unknown.

[0009]

Means for Solving the Problems Claim 1 is provided with a geomagnetic sensor 1, an inclination sensor 2, and a magnetic output detected by the geomagnetic sensor 1 and a posture angle detected by the inclination sensor 2 are inputted. A correction calculation unit for correcting the inclination of the magnetic output horizontally by the attitude angle;
2 is provided with an azimuth calculation unit 33 for calculating the magnetic azimuth し て by inputting the calculation result, an antenna 4 for receiving a GPS signal transmitted from a GPS satellite, and inputting a GPS signal and outputting latitude and longitude information And a declination calculator 34 for inputting latitude and longitude information and calculating a declination δψ, and a true azimuth ψ ′ corrected by adding the magnetic azimuth ψ and the declination δψ. A geomagnetic azimuth sensor provided with an adder 35 for outputting the data is constructed.

In the terrestrial magnetism sensor according to claim 1, the terrestrial magnetism sensor 1 is rolled.
The tilt sensor 2 includes an axial geomagnetic sensor X, a pitci axial geomagnetic sensor Y, and a yaw axial geomagnetic sensor Z, and the tilt sensor 2 is a roll axial tilt sensor ro.
A geomagnetic azimuth sensor consisting of two sensors, ll and pitci, is provided.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the embodiment shown in FIG. The embodiment of FIG. 1 has a configuration in which the magnetic azimuth is automatically corrected even if the longitude and latitude are unknown, and the true azimuth is obtained.
An antenna for receiving a signal, a GPS receiver for inputting a GPS signal and outputting latitude and longitude information, and a declination calculator are equivalent to those added to the embodiment of FIG.

The geomagnetic sensor 1 and the tilt sensor 2 in FIG. 1 are common to the sensors used in the embodiment of FIG. Reference numeral 4 denotes an antenna for receiving a GPS signal transmitted from a GPS satellite. 5 is G received by antenna 4
This is a GPS receiver that inputs a PS signal and outputs latitude and longitude information.

The arithmetic processing unit 30 inputs the latitude / longitude information output from the GPS receiver 5 to the arithmetic processing unit 3 of FIG. 2 to calculate a declination δψ, and an azimuth calculation unit 33. Magnetic azimuth あ る which is the calculation result of ψ and the deflection angle calculation unit 34
And an adder 35 that outputs the true azimuth ψ ′ which is corrected by adding the argument δψ, which is the calculation result of の, is added. The geomagnetic azimuth sensor according to the present invention also provides the correction calculator 32 of the arithmetic processing unit 30 with the X detected by the geomagnetic sensor 1.
The axial magnetic output x _tm , the Y axial magnetic output y _tm and the Z axial magnetic output z _tm are input, and the roll axis attitude angle φ and pitc detected by the tilt sensor 2.
The i-axis orientation angle θ is input, and the rotation matrix is calculated here. As a result, the inclination of the magnetic output of the geomagnetic sensor 1 of the three orthogonal axes is corrected by the attitude angle detected by the inclination sensor 2, and is converted into data of the magnetic output that is horizontal and orthogonal.

[0014]

(Equation 3) The declination formula in the Japanese Islands is excerpted from the 1995 scientific chronology as shown below. By the way, the geomagnetism is not constant and changes periodically and irregularly. This is an approximate expression of 1990 values. δψ = 7 ゜ 22.82 ′ + 21.01 ′ × △ Γ−7.3
6 '× △ Λ-0.197' × △ Γ ² + 0.587 '× △
Γ · △ Λ−0.961 ′ × △ Λ ² (westward deviation) [deg] where △ Γ = Γ−37 ゜ N △ Λ = Λ-138 ゜ E Γ: latitude [deg] Λ: longitude [deg] The data corrected by the correction calculator 32 is input to the azimuth calculator 33, where the magnetic azimuth ψ is calculated.

[0015]

(Equation 4) As described above, one data is divided by the other data, and arctan of the division result is used as the magnetic direction. Here, the geomagnetic azimuth sensor of the present invention, on the other hand, receives a GPS signal transmitted from a GPS satellite via the antenna 4, and the GPS receiver 5 outputs the latitude / longitude information of the receiving point based on this. The latitude / longitude information obtained from the GPS receiver 5 is input to the argument calculating unit 34 of the arithmetic processing unit 30, where the argument δψ is calculated.
This declination δψ is added to the magnetic azimuth ψ which is the calculation result of the azimuth calculation unit 33 in the adding unit 35, and the true azimuth ψ 'is obtained as an addition result.

[0016]

As described above, according to the present invention, a positioning device using a GPS satellite can automatically obtain latitude and longitude information even if the longitude and latitude of the measurement point are unknown. This is read by a computer to automatically calculate the argument. The magnetic azimuth is corrected in real time using the automatically calculated declination, and the true azimuth at the current position can be obtained.

Since the GPS satellite covers the entire earth surface as a measurement range, the true bearing can be measured and calculated at any point on the earth surface in real time. In addition, the magnetic azimuth sensor can be mounted on an aircraft, a traveling vehicle, or another moving body to automatically correct the detection result of the geomagnetic sensor even in a moving state.

[Brief description of the drawings]

FIG. 1 illustrates an embodiment.

FIG. 2 is a diagram showing an azimuth axis.

FIG. 3 illustrates a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Geomagnetic sensor 2 Inclination sensor 3 Arithmetic processing unit 30 Arithmetic processing unit 31 Calculator 32 Correction calculation part 33 Azimuth calculation part 34 Declination angle calculation part 35 Addition part 4 Antenna 5 GPS receiver

Claims (2)

[Claims] 1. A magnetic sensor comprising: a tilt sensor; a magnetic output detected by the geomagnetic sensor and an attitude angle detected by the tilt sensor are input, and the tilt of the magnetic output is corrected horizontally by the attitude angle. A correction calculation unit, an azimuth calculation unit for calculating a magnetic azimuth by inputting a calculation result of the correction calculation unit, an antenna for receiving a GPS signal transmitted from a GPS satellite, and a GPS signal input A GPS receiver that outputs latitude and longitude information, and a declination calculation unit that calculates the declination by inputting the latitude and longitude information, and calculates the true direction corrected by adding the magnetic direction and the declination. A geomagnetic azimuth sensor comprising an adder for outputting. 2. The geomagnetic direction sensor according to claim 1, wherein the geomagnetic sensor is a geomagnetic sensor in a roll axis direction, pit.
It consists of a geomagnetic sensor in the direction of the ci axis and a geomagnetic sensor in the direction of the yaw axis. The tilt sensor is a tilt sensor in the roll axis direction and pit.
A geomagnetic azimuth sensor comprising two sensors: a tilt sensor in a ci-axis direction.