Automatic testing device for magnetic compass

Abstract

The invention provides an automatic testing device for a magnetic compass. The automatic testing device comprises a three-dimensional magnetic field coil, a three-axis fluxgate sensor, a geomagnetic offset current source, a geomagnetic reproduction current source and an active magnetic eraser, the three-dimensional magnetic field coil is used for converting the geomagnetic compensation current, the geomagnetic reproduction current and the interference magnetic field compensation current into corresponding magnetic fields; the three-axis fluxgate sensor is used for sensing a three-axis magnetic field in a uniform area of the three-dimensional magnetic field coil and outputting an analog magnetic signal, and is fixed in the uniform area of the three-dimensional magnetic field coil, three sensitive axes of the three-axis fluxgate sensor are respectively parallel to three magnetic axes of the three-dimensional magnetic field coil, and the three-axis fluxgate sensor is connected with the active magnetic eraser; the geomagnetic counteracting current source is used for generating direct current for counteracting a geomagnetic field in a uniform area of the three-dimensional magnetic field coil and is composed of three high-precision program control constant current sources, and three-channel output of the geomagnetic counteracting current source is connected with a three-dimensional geomagnetic counteracting winding of the three-dimensional magnetic field coil.

Description

Technical Field

[0001] The invention belongs to the technical field of magnetic compass testing, and in particular relates to an automatic magnetic compass testing device. Background Art

[0002] Magnetic compasses are widely used in geomagnetic navigation, geological exploration and other fields. Magnetic compass index testing is an important task to confirm its performance. When a large number of magnetic compasses need to be tested for performance indicators, how to ensure the test accuracy of the magnetic compass while improving the test efficiency and reducing the test cost is a difficult problem faced by the field of magnetic compass testing technology.

[0003] The main way to improve the efficiency of magnetic compass testing in the prior art is to shorten the time for the magnetic field reproduction of the test point. The magnetic field reproduction schemes of conventional magnetic compass testing devices mainly include non-magnetic manual turntable test scheme, non-magnetic electric turntable test scheme and non-magnetic hydraulic turntable test scheme. Among them:

[0004] The non-magnetic manual turntable test method has the characteristics of low test cost and high system reliability, but it has the problems of low test efficiency and low test accuracy.

[0005] The non-magnetic electric turntable test method and the non-magnetic hydraulic turntable test method have the characteristics of high test efficiency, but have the problems of low test accuracy and high test cost. In addition, due to the high complexity of the system, the reliability is low. Summary of the invention

[0006] In order to solve the above problems, the present invention provides an automatic testing device for a magnetic compass.

[0007] The present invention is achieved through the following technical solutions.

[0008] A magnetic compass automatic testing device, comprising a three-dimensional magnetic field coil, a three-axis fluxgate sensor, a geomagnetic offset current source, a geomagnetic reproduction current source, and an active demagnetizer;

[0009] The three-dimensional magnetic field coil is used to convert geomagnetic compensation, geomagnetic reproduction and interference magnetic field compensation currents into corresponding magnetic fields;

[0010] The three-axis fluxgate sensor is used to sense the three-axis magnetic field in the uniform area of ​​the three-dimensional magnetic field coil and output an analog magnetic signal. It is fixed in the uniform area of ​​the three-dimensional magnetic field coil. The three sensitive axes of the three-axis fluxgate sensor are respectively parallel to the three magnetic axes of the three-dimensional magnetic field coil. The three-axis fluxgate sensor is connected to an active demagnetizer.

[0011] The geomagnetic compensation current source is used to generate a direct current to offset the geomagnetic field in the uniform area of ​​the three-dimensional magnetic field coil, and is composed of three high-precision programmable constant current sources, whose three-channel outputs are connected to the three-dimensional geomagnetic compensation winding of the three-dimensional magnetic field coil;

[0012] The geomagnetic reproduction current source is used to generate a direct current to reproduce the geomagnetic field in the uniform area of ​​the three-dimensional magnetic field coil according to the host computer test signal, and its three-channel output is connected to the three-dimensional geomagnetic reproduction winding of the three-dimensional magnetic field coil, and its program-controlled input end is connected to the geomagnetic compensation control output end of the host computer system;

[0013] The active demagnetizer is used to process the magnetic field signal output by the fluxgate sensor and the test signal output by the host computer system to generate a current for compensating the dynamic interference magnetic field.

[0014] Beneficial effects of the present invention:

[0015] 1. High test accuracy: Compared with the general magnetic compass test device, the present invention not only adopts a high-precision programmable current source, but also uses an active demagnetizer to compensate for the interference magnetic field, so the reproduced magnetic field noise is lower and the test accuracy is higher;

[0016] 2. High test efficiency: Compared with the general magnetic compass test device, the present invention simulates the change of the magnetic field of the magnetic compass at different directions by reproducing the three components of the earth's magnetic field. The efficiency of controlling the change of the magnetic field by current is higher than that of the change of the magnetic field caused by the mechanical rotation of the turntable, so it has higher test efficiency.

[0017] 3. Low test cost: The present invention realizes the reproduction of the three components of geomagnetism at different azimuths through a current source, which is significantly lower in cost than the solution of realizing the reproduction of the three components of geomagnetism at different azimuths with a turntable;

[0018] 4. The three-axis fluxgate sensor selected in the present invention should have the characteristics of low noise, wide frequency response, high linearity, high orthogonality, small size and low temperature drift;

[0019] 5. The present invention has been verified to have high reliability through testing. DETAILED DESCRIPTION

[0020] Exemplary embodiments of the present invention are described in detail below.

[0021] The present invention discloses an automatic magnetic compass testing device, comprising a three-dimensional magnetic field coil, a three-axis fluxgate sensor, a geomagnetic offset current source, a geomagnetic reproduction current source, an active demagnetizer, a host computer system and a control cabinet; wherein:

[0022] The three-dimensional magnetic field coil is used to convert geomagnetic compensation, geomagnetic reproduction and interference magnetic field compensation currents into corresponding magnetic fields; in this embodiment, the three-dimensional magnetic field coil includes a coil frame and a coil winding, and the coil frame structure is entirely made of non-magnetic materials; the coil winding includes a three-dimensional geomagnetic offset winding, a three-dimensional geomagnetic reproduction winding and a three-dimensional interference magnetic field compensation winding;

[0023] The three-axis fluxgate sensor is used to realize accurate perception of the three-axis magnetic field in the uniform area of ​​the three-dimensional magnetic field coil and output analog magnetic signals. It is fixed in the uniform area of ​​the three-dimensional magnetic field coil. The three sensitive axes of the three-axis fluxgate sensor are respectively parallel to the three magnetic axes of the three-dimensional magnetic field coil. The three-axis fluxgate sensor is connected to an active demagnetizer. In specific implementation, the selected three-axis fluxgate sensor should have the characteristics of low noise, wide-band response, high linearity, high orthogonality, small size and low temperature drift.

[0024] The geomagnetic compensation current source is used to generate a direct current to offset the geomagnetic field in the uniform area of ​​the three-dimensional magnetic field coil. It is composed of three high-precision programmable constant current sources installed in the control cabinet, and its three-channel output is connected to the three-dimensional geomagnetic compensation winding of the three-dimensional magnetic field coil;

[0025] The geomagnetic reproduction current source is used to generate a direct current for reproducing the geomagnetic field in the uniform area of ​​the three-dimensional magnetic field coil according to the host computer test signal. It is composed of three high-precision programmable constant current sources installed in the control cabinet. Its three-channel output is connected to the three-dimensional geomagnetic reproduction winding of the three-dimensional magnetic field coil, and its programmable input terminal is connected to the geomagnetic compensation control output terminal of the host computer system;

[0026] The active demagnetizer is used to process the magnetic field signal output by the fluxgate sensor and the test signal output by the host computer system to generate a current for compensating the dynamic interference magnetic field. It is also used for powering the three-axis fluxgate sensor and displaying the magnetic field value. In this embodiment, the active demagnetizer is installed in the control cabinet and consists of a programmable voltage source module, a control module, a power amplifier module, a signal acquisition and display module, a power conversion module, a chassis shell, a communication port, a sensor port and a current output port. The sensor port of the active demagnetizer is connected to the three-axis fluxgate sensor, the communication port of the active demagnetizer is connected to the industrial computer of the host computer, and the current output port of the active demagnetizer is connected to the three-dimensional interference magnetic field compensation winding of the three-dimensional magnetic field coil.

[0027] The host computer system is used to calculate the geomagnetic reproduction current value and control the output of the geomagnetic reproduction current source according to the magnetic compass test requirements; in this embodiment, the host computer system includes an industrial computer and host computer software, which are installed in a control cabinet. The industrial computer includes multiple serial communication ports, which are respectively connected to the geomagnetic reproduction current source and the active demagnetizer.

[0028] The control cabinet is used to install and fix the geomagnetic compensation current source, geomagnetic reproduction current source, active demagnetizer and industrial computer of the host system in the test device; in this embodiment, a non-magnetic cabinet made of aluminum alloy material is arranged at a position more than 5m away from the three-dimensional magnetic field coil.

[0029] The working process of the automatic testing device for magnetic compass of the present invention is as follows:

[0030] Step 1: Offset the geomagnetic field; power on the geomagnetic compensation current source, the three-axis fluxgate sensor and the active demagnetizer, turn off the demagnetization function of the active demagnetizer, observe the magnetic field value displayed by the active demagnetizer in real time, adjust the three-channel current size and direction output by the geomagnetic compensation current source, and offset the geomagnetic field in the uniform area of ​​the three-dimensional magnetic field coil;

[0031] Step 2: Reproduce the geomagnetic field; turn on the host computer system and the geomagnetic reproduction current source. The host computer system first calculates the three-component values ​​of the geomagnetic field at different attitude angles according to the attitude angle test point requirements, and then calculates the three-channel geomagnetic compensation values ​​according to the geomagnetic reproduction winding coil constants. The geomagnetic field reproduction current source outputs current according to the host computer control signal, and reproduces the geomagnetic field corresponding to the test point through the three-dimensional geomagnetic reproduction winding;

[0032] Step 3: Offset the dynamic interference magnetic field; turn on the demagnetization function of the active demagnetizer. The active demagnetizer outputs the interference magnetic field compensation current according to the three components of the geomagnetic field output by the host computer and the current output by the fluxgate sensor, and generates a compensation magnetic field in real time through the three-dimensional interference magnetic field compensation winding.

[0033] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0034] For those skilled in the art, it is obvious that the embodiments of the present invention are not limited to the details of the above exemplary embodiments, and the embodiments of the present invention can be implemented in other specific forms without departing from the spirit or basic features of the embodiments of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the embodiments of the present invention is limited by the attached claims rather than the above description, so it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the embodiments of the present invention. In addition, it is obvious that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units, modules or devices stated in the system, device or terminal claims can also be implemented by the same unit, module or device through software or hardware. The words first, second, etc. are used to indicate names, and do not indicate any particular order.

[0035] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solutions of the embodiments of the present invention and are not intended to limit them. Although the embodiments of the present invention have been described in detail with reference to the above preferred implementation modes, those skilled in the art should understand that the technical solutions of the embodiments of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A magnetic compass automatic testing device, characterized in that: It includes three-dimensional magnetic field coil, three-axis fluxgate sensor, geomagnetic offset current source, geomagnetic reproduction current source, and active demagnetizer; The three-dimensional magnetic field coil is used to convert geomagnetic compensation, geomagnetic reproduction and interference magnetic field compensation currents into corresponding magnetic fields; The three-axis fluxgate sensor is used to sense the three-axis magnetic field in the uniform area of ​​the three-dimensional magnetic field coil and output an analog magnetic signal. It is fixed in the uniform area of ​​the three-dimensional magnetic field coil. The three sensitive axes of the three-axis fluxgate sensor are respectively parallel to the three magnetic axes of the three-dimensional magnetic field coil. The three-axis fluxgate sensor is connected to an active demagnetizer. The geomagnetic compensation current source is used to generate a direct current to offset the geomagnetic field in the uniform area of ​​the three-dimensional magnetic field coil, and is composed of three high-precision programmable constant current sources, whose three-channel outputs are connected to the three-dimensional geomagnetic compensation winding of the three-dimensional magnetic field coil; The geomagnetic reproduction current source is used to generate a direct current to reproduce the geomagnetic field in the uniform area of ​​the three-dimensional magnetic field coil according to the host computer test signal, and its three-channel output is connected to the three-dimensional geomagnetic reproduction winding of the three-dimensional magnetic field coil, and its program-controlled input end is connected to the geomagnetic compensation control output end of the host computer system; The active demagnetizer is used to process the magnetic field signal output by the fluxgate sensor and the test signal output by the host computer system to generate a current for compensating the dynamic interference magnetic field.

2. A magnetic compass automatic testing device as claimed in claim 1, characterized in that: The three-dimensional magnetic field coil comprises a coil frame and a coil winding, wherein the coil winding comprises a three-dimensional geomagnetic offset winding, a three-dimensional geomagnetic reproduction winding and a three-dimensional interference magnetic field compensation winding.

3. A magnetic compass automatic testing device as claimed in claim 2, characterized in that: The coil frame structure is entirely made of non-magnetic materials.

4. A magnetic compass automatic testing device as claimed in claim 1, 2 or 3, characterized in that: The device also includes a host computer system, which is used to calculate the geomagnetic recurring current value and control the output of the geomagnetic recurring current source according to the magnetic compass test requirements.

5. The automatic magnetic compass testing device according to claim 4, characterized in that: The device also includes a control cabinet for installing a geomagnetic offset current source, a geomagnetic reproduction current source, an active demagnetizer and an industrial computer of a host computer system in a fixed test device.

6. The automatic magnetic compass testing device according to claim 5, characterized in that: The control cabinet is a non-magnetic cabinet made of aluminum alloy material and is arranged at a position more than 5m away from the three-dimensional magnetic field coil.

7. The automatic magnetic compass testing device according to claim 4, characterized in that: The host computer system includes an industrial computer and host computer software. The industrial computer includes multiple serial communication terminals, which are respectively connected to the geomagnetic reproduction current source and the active demagnetizer.

8. The automatic magnetic compass testing device according to claim 7, characterized in that: The active demagnetizer is composed of a programmable voltage source module, a control module, a power amplifier module, a signal acquisition and display module, a power conversion module, a chassis shell, a communication port, a sensor port and a current output port. The sensor port of the active demagnetizer is connected to a three-axis fluxgate sensor, the communication port of the active demagnetizer is connected to an industrial computer of a host computer, and the current output port of the active demagnetizer is connected to a three-dimensional interference magnetic field compensation winding of a three-dimensional magnetic field coil.