CN106092106B - Eulerian angles scaling method between star sensor and Magnetic Sensor - Google Patents

Abstract

The present invention provides Eulerian angles scaling methods between a kind of star sensor and Magnetic Sensor.Mainly solves the problems, such as the method low precision of Eulerian angles between existing assessment star sensor and fluxgate sensor.By the way that star sensor and fluxgate sensor to be mounted on no magnetic turntable, cooperation star simulator is tested and assessed Eulerian angles between star sensor and fluxgate sensor in non-magnetic environment.With measurement accuracy height, feature easy to use.

Description

Calibration method of Euler angle between star sensor and magnetic sensor

technical field

The invention relates to the field of electromagnetism, and can be used in geomagnetism detection and composite navigation systems, a method for calibrating the Euler angle between a star sensor and a magnetic sensor.

Background technique

In modern geomagnetic observation satellites, the fluxgate sensor is mainly used to obtain high-precision geomagnetic field vector data, and the magnetic field data of magnetic survey satellites requires that the error of each component be on the order of nT. This indicator puts forward higher requirements on the accuracy of fluxgate space measurement. The amplitude of the geomagnetic field strength varies within the range of ±50000nT. If there is a 2" error in the space azimuth of the fluxgate, the error of a certain component of the measured magnetic field data will reach 0.49nT. In order to meet the requirements of the index, the magnetic field needs to be To strictly control the positioning accuracy of the space azimuth angle of the fluxgate, it is necessary to use the star sensor to determine the space attitude of the fluxgate, and it is only known to eliminate the Euler angle between the fluxgate sensor and the star sensor, and to eliminate or compensate the Euler angle error , in order to accurately obtain the attitude of the fluxgate.

The existing technology is to choose a place where the magnetic field and magnetic field gradient are uniform, and place the optical platform carrying the star sensor and the fluxgate sensor on a turntable that can rotate 360° around the circumference and can be raised in the vertical direction. Place an identical fluxgate sensor 6m beside the turntable, and use the azimuth data measured by the star sensor, as well as the fluxgate data and auxiliary fluxgate data on the optical platform to fit the relationship between the star sensor and the fluxgate. Euler angles.

The existing technology has the following deficiencies: ①Although real starry sky images can be obtained from stargazing outside, it is difficult to evaluate the real performance of very high-precision star sensors due to the influence of temperature, humidity, atmospheric disturbance, and misty air on the ground; ② The geomagnetic field conditions of the outdoor test site are extremely demanding, and non-geomagnetic disturbances are not allowed. With the increasing frequency of human activities, it is difficult to find a pure geomagnetic environment test site. Therefore, the method of outdoor evaluation of the Euler angle between the star sensor and the fluxgate sensor is not only difficult to further improve the accuracy, but even impossible to achieve.

Contents of the invention

The purpose of the present invention is to solve the above-mentioned problems in the prior art, and further provide a method for calibrating the Euler angle between the star sensor and the magnetic sensor, which effectively avoids the influence of atmospheric conditions and geomagnetic instability factors on the calibration accuracy.

The technical solution of the present invention is: a method for calibrating Euler angles between a star sensor and a magnetic sensor,

Ⅰ. Establish a three-dimensional rectangular NED coordinate system, install the star simulator on the H-shaped linear guide rail, and in the zero magnetic environment device, ensure that the light emitted by the star simulator collimator is consistent with the earth's northward N direction, and the collimator emits light The direction is perpendicular to the ground D direction, and the side of the star simulator 1 is perpendicular to the east direction E direction;

Ⅱ. Place the non-magnetic turntable in the zero-order environment device. When the 0-degree scale lines are orthogonal to each other, ensure that the outermost 0-degree scale line points to the N direction, the middle 0-degree scale line is perpendicular to the D direction, and the inner 0-degree line is perpendicular to the D direction. The scale line refers to the E direction;

Ⅲ. Establish an orthogonal three-axis standard magnetic field generator outside the non-magnetic turntable. The axes of the upper and lower coils are parallel to the D direction, the left and right coil axes are parallel to the N direction, and the front and rear coil axes are parallel to the E direction. There is a deviation from the NED coordinates during assembly. , the test deviation calibration value Tc1=(αc, βc, γc,), the coil orthogonality will also cause errors, the value after calibration is Tce=(0, ζ, η,) the composite error is Tc=Tc1+Tce;

Ⅳ. Install the star sensor and fluxgate sensor on the inner layer of the non-magnetic turntable. The non-magnetic turntable carries the rotation of the star sensor-fluxgate system to be tested. The star simulator passes E and D on the H-shaped linear guide rail. Adjust the direction to ensure that the parallel light can be observed by the star sensor. When the optical axis of the star sensor is consistent with the optical axis of the star simulator, record the three-axis NED reading of the turntable TNg=(αNg, βEg, γDg);

Ⅴ. The fluxgate sensor rotates with the turntable in the known uniform vector magnetic field generated by the three-axis standard magnetic field generator. When the data detected by the three-axis fluxgate sensor is consistent with the generated known magnetic field, the fluxgate sensor The three axes coincide with the NED coordinate system. At this time, record the three-axis NED reading TNc=(αNc, βEc, γDc) of the non-magnetic turntable;

Ⅵ. The above steps refer to the NED coordinate system. The Euler angle relationship between the fluxgate sensor and the NED coordinate system is TNc-Tc, and the Euler angle relationship between the star sensor and the NED coordinate system is TNg, and the final star sensor and NED coordinate system are obtained. The Euler angle relationship of the fluxgate sensor is: TNg-(TNc-Tc).

Further, the non-magnetic turntable 3 is provided with an H-shaped linear guide rail, and a star sensor and a fluxgate sensor are installed on the H-shaped linear guide rail.

The beneficial effects of the present invention are: by adopting the technical scheme of the present invention, a method for calibrating the Euler angle between the star sensor and the fluxgate sensor based on the zero magnetic environment device can effectively avoid atmospheric conditions and geomagnetic field instability factors The impact on calibration accuracy is measured accurately.

Instructions attached

Fig. 1 is a schematic diagram of the structure of the present invention.

Fig. 2 is a schematic structural view of the non-magnetic turntable inner layer with H-shaped linear guide rail of the present invention.

In the figure, 1-star simulator, 2-three-axis standard magnetic field generating device, 3-non-magnetic turntable.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings: the present embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation is provided, but the protection scope of the present invention is not limited to the following embodiments.

As shown in Figure 1, a method for calibrating Euler angles between a star sensor and a magnetic sensor involved in this embodiment,

Ⅰ. Establish a three-dimensional rectangular NED coordinate system, install the star simulator 1 on the H-shaped linear guide rail, have the position adjustment function in the D direction and the E direction, and in the zero magnetic environment device, ensure that the star simulator 1 from the collimator The light is consistent with the north direction N of the earth, the light emitting direction of the collimator is perpendicular to the ground D direction, and the side of the star simulator 1 is perpendicular to the east direction E direction, so that the coordinates of the star simulator are related to the earth coordinates, and there may be deviations from the NED coordinates , to calibrate αg, βg, γg

Ⅱ. The non-magnetic turntable 3 is placed in the zero-order environment device. The non-magnetic turntable 3 is used to prevent the magnetic signal generated by the turntable from affecting the calibration of the Euler angle of the fluxgate sensor. When the 0-degree scale lines are orthogonal to each other, Make sure that the outermost 0-degree scale line points to the N direction, the middle 0-degree scale line is perpendicular to the D direction, and the inner 0-degree scale line points to the E direction. It may be difficult to achieve accurate positioning during the installation process, so you can get 30 degrees The deviation angles α0, β0, γ0 between the scale line and the NED coordinates.

Ⅲ. Establish an orthogonal three-axis standard magnetic field generating device 2 outside the non-magnetic turntable 3. The axes of the upper and lower coils are parallel to the D direction, the left and right coil axes are parallel to the N direction, and the front and rear coil axes are parallel to the E direction. Coordinate deviation, test deviation calibration value Tc1=(αc, βc, γc), coil orthogonality will also cause errors, the value after calibration is Tce=(0, ζ, η), and the composite error is Tc=Tc1+Tce;

Ⅳ. Install the star sensor and fluxgate sensor on the inner layer of the non-magnetic turntable 3. The non-magnetic turntable 3 carries the rotation of the star sensor-fluxgate system to be tested, and the star simulator 1 passes on the H-shaped linear guide rail. The adjustment of E and D directions ensures that the parallel light can be observed by the star sensor. When the optical axis of the star sensor is consistent with the optical axis of the star simulator, record the three-axis NED reading of the turntable TNg=(αNg, βEg, γDg);

V. The fluxgate sensor rotates with the turntable in the known uniform vector magnetic field generated by the three-axis standard magnetic field generator 2. When the data detected by the three-axis fluxgate sensor is consistent with the generated known magnetic field, the fluxgate The three axes of the sensor coincide with the NED coordinate system, and record the three-axis NED reading TNc=(αNc, βEc, γDc) of the non-magnetic turntable 3 at this time;

Ⅵ. The above steps refer to the NED coordinate system. The Euler angle relationship between the fluxgate sensor and the NED coordinate system is TNc-Tc, and the Euler angle relationship between the star sensor and the NED coordinate system is TNg, and the final star sensor and NED coordinate system are obtained. The Euler angle relationship of the fluxgate sensor is: TNg-(TNc-Tc).

Further, an H-type linear guide rail is set on the non-magnetic turntable 3, and a star sensor and a fluxgate sensor are installed on the H-type linear guide rail, so that the star sensor or the fluxgate sensor can be translated to the position of the turntable through the guide rail. The position adjustment of the star simulator will be greatly reduced when calibrating the star sensor, which increases the difficulty of calibrating the star sensor; the fluxgate sensor is moved to the center of the turntable, so that when it rotates with the turntable, the space The smaller range means higher uniformity of the magnetic field, thus improving the calibration accuracy of the fluxgate sensor coordinate system.

The above are only preferred specific implementations of the present invention. These specific implementations are all based on different implementations under the overall concept of the present invention, and the scope of protection of the present invention is not limited thereto. Anyone familiar with the technical field Within the technical scope disclosed in the present invention, any changes or substitutions that can be easily conceived by a skilled person shall fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (2)

1. Eulerian angles scaling method between a kind of star sensor and Magnetic Sensor, it is characterised in that：

I, three-dimensional right angle NED coordinate system is established, star simulator (1) is mounted in H-type linear guide, and in zero magnetic environment device In, guarantee star simulator (1) parallel light tube issue light it is consistent with the earth direction north orientation N, parallel light tube light emission direction perpendicular to The ground direction D, star simulator (1) side is perpendicular to the direction east orientation E；

II, it will be placed in without magnetic turntable (3) in zero magnetic environment device, and when 0 degree of graduation mark is mutually orthogonal, guarantee 0 degree of outermost layer Graduation mark refers to the direction N, and 0 degree of middle layer graduation mark refers to the direction E perpendicular to the direction D, 0 degree of graduation mark of internal layer；

III, three axis standard Magnetic Field generating device (2) of orthogonality is established outside no magnetic turntable (3), upper and lower distribution coil axis is parallel In the direction D, left and right coil axis is parallel to the direction N, and front and back coil axis is parallel to the direction E, and when assembly exists inclined with NED coordinate Difference, measurement error calibration value Tc1=(α c, β c, γ c), coil orthogonality can equally cause error, and numerical value is Tce=after calibration (0, ζ, η), resultant error Tc=Tc1+Tce；

IV, star sensor, fluxgate sensor are installed on no magnetic turntable (3) internal layer, no magnetic turntable (3) carries star to be measured Sensor-magnetic flux door system rotation, star simulator (1) pass through the adjustment in the direction E, D in H-type linear guide, it is ensured that directional light It can be observed by star sensor, when star sensor optical axis is consistent with star simulator optical axis, record the three axis NED reading of turntable TNg=(α Ng, β Eg, γ Dg)；

V, with turntable in fluxgate sensor known uniform Vector Magnetic Field caused by three axis standard Magnetic Field generating devices (2) Rotation, when the data that three repacking of fluxgate sensor measures are consistent with the known magnetic field of generation, three axis of fluxgate sensor with NED coordinate system is overlapped, and records three axis NED reading TNc=(α Nc, β Ec, γ Dc) of no magnetic turntable (3) at this time；

VI, Euler's angular dependence of above each step reference NED coordinate system, fluxgate sensor and NED coordinate system is TNc-Tc, Euler's angular dependence of star sensor and NED coordinate system is TNg, and the Eulerian angles for obtaining final star sensor and fluxgate sensor are closed System is：TNg-(TNc-Tc).

2. Eulerian angles scaling method between star sensor according to claim 1 and Magnetic Sensor, it is characterised in that：Described H-type linear guide is set on no magnetic turntable (3), star sensor, fluxgate sensor are installed in H-type linear guide.