JPH0618277A - Calibrating method of inertia reference device - Google Patents

Abstract

PURPOSE:To obtain a calibrating method of an inertia reference device which makes it possible to calibrate an initial scale factor or a drift bias of the inertia reference device of a moving body which is thrown into the air or sea or moved from a moving base such as a ship or the like in a short time at the moving spot and to update the data. CONSTITUTION:An initial scale factor or a bias of an inertia reference device 14 of a moving body 12 which moves from a moving base 10 or a launching means 16 of the moving base upon receipt of the moving force is calibrated from the comparing result of the data of a reference inertia device 20 and that of the inertia reference device 14 of the moving body 12 based on the oscillation input impressed to the moving base 10 or projecting means 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for calibrating an inertial reference device provided in a moving body emitted from a moving body such as a ship or an aircraft into the air or the sea. The present invention relates to a calibration method for calibrating a bias (drift output when an input has a zero value) and a scale factor (output value / magnification value determined by an input value) of an angle detection function in a short time.

[0002]

2. Description of the Related Art Conventionally, calibration of a gyro scale factor incorporated in an inertial reference device mounted on a flying vehicle is as follows.
The only way to do this is to input an accurate angle using a rotary table at the factory. Also, if the moving base is a ship, etc., the correct position such as GPS can be used to calibrate the gyro bias under the shaking of the moving base. Needing input.

[0003]

That is, in order to calibrate the inertial reference device of a moving body, the bias and scale factor of the inertial reference device directly incorporated at the start of flight of the moving body can be calibrated in a short time. A highly practical method has not been provided yet.

Therefore, an object of the present invention is to set the bias and scale factor of each sensor of the inertial reference device mounted on the moving body on the moving body for a short time at the start of flight of the moving body. It is intended to provide a feasible calibration method.

[0005]

According to the present invention, there is provided a method of calibrating a scale factor and a bias of an inertial reference device included in a moving body mounted on a moving body and flying and moving therefrom. An inertial reference device for reference is previously mounted on the flight launching means of the moving body provided on the mother body so that the scale factor and bias of the reference inertial reference device are always correct in the inertial reference device of the movable mother body. Corrected according to the value, given a predetermined shaking input to the flight launch means, the shaking input is measured by the reference inertial reference device and the output value corresponding to the measured input is obtained as a reference output value, At the same time, the output value of the inertial reference device included in the moving body is measured as the output value to be calibrated, the difference value between the reference output value and the output value to be calibrated is obtained, and the scale of the inertial reference device of the moving body is calculated. Calibration method for inertial reference unit being characterized in that so as to correct the factor and bias is provided.

According to the present invention, there is further provided a method of calibrating a scale factor and a bias of an inertial reference device included in a moving body which is mounted on the moving body and flies and moves from the moving body. The reference device is an inertia reference device for reference, and a predetermined swing input is given around the heading axis of the moving body, the swing input is measured by the reference inertia reference device, and an output value corresponding to the measurement input is used as a reference. Obtained as an output value, and at the same time, the output value of the inertial reference device provided in the moving body is measured as an output value to be calibrated,
There is provided a method for calibrating an inertial reference device, wherein a difference value between the reference output value and an output value to be calibrated is obtained to correct a scale factor and a bias of the inertial reference device of the moving body.

[0007]

According to the method of configuring the inertial reference device having the above-described two configurations, the scale factor and the drift bias are updated by the calibration at the movement start site of the moving body immediately before the start of the movement to update the latest scale factor and bias. The movement is started based on and.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan view for explaining a case where the method of the present invention is applied to an embodiment in which a ship is a moving body and a torpedo is a moving body, and FIG. 2 is a flight of the moving body in the same embodiment. FIG. 3 is a partially enlarged explanatory view showing the calibration of the calibration means in the preparation state, FIG. 3 is a graph showing the relationship between the input and the output of the inertial reference device, and FIG. 4 is a perspective view showing another embodiment to which the calibration method of the present invention is applied. FIG. 5 and FIG. 5 are graphs similar to FIG.

Referring to FIGS. 1 and 2, as one embodiment to which the method for calibrating an inertial reference device according to the present invention is applied, a moving body 10 made up of a ship's boat and a moving body 12 made up of torpedoes are passed through the air or directly. 2 shows a case where the bias and scale factor of the inertial reference device 14 mounted on the moving body 12 is calibrated in advance before it is launched into the sea and is made to fly.

The moving body 10 is equipped with a launching device 16 for launching the moving body 12 at an appropriate position on the body, and the moving body 10 itself is also equipped with an inertial reference device 18 used in its navigation process. It has. The front-back direction of the moving mother body is selected as the X-axis.

On the other hand, the moving body 12 is the moving body 10 described above.
Is launched by the launching device 16 of the mobile device 1 and starts to fly.
The launching port is projected to the outside of the ship from the state of being housed on the side of the ship, which is 0, and is set to the launching angle β0 controlled according to the target in the X-axis direction.

To carry out the calibration method of the present invention, the launch tube 16 is fitted with an inertial reference device 20 for a calibration reference. Then, the inertial reference device 20 for this calibration reference is sometimes calibrated by the inertial reference device 18 which the moving mother body 10 originally has, and its detection accuracy is maintained.

At the time of calibration immediately before the launch of the moving body 12, the moving body 12 including the mounted inertial reference device 14 is mounted on the launching device 1.
Swing with 6. This swinging causes the launching device 16 to move in a substantially horizontal plane with respect to the launch axis by a known amount of positive and negative input angles (±
β1) is applied. Then, this input angle (± β1) is measured by the inertial reference device 20 of the launching device 16 whose accuracy is maintained in advance, and the input around the heading of the inertial reference device 14 of the moving body 12 is made with this measured value as a reference value. Calibrate the scale factor (Kh) and drift rate bias (Dh) for axis angle detection. In addition, the inertial reference device 20 of the launching device 16 is also included.
The heading, pitch angle, and roll angle are input to the inertia reference device 14 of the moving body 12 as initial values.

Furthermore, if time is allowed for the firing time of the moving body 12, the shaking input by the angle ± β is repeatedly applied several times to reduce the influence of disturbance, and the accuracy of the reference value measured according to it is reduced. High accuracy can be achieved.

In FIG. 3, the horizontal axis represents the swing input measured by the inertial reference device 20 of the launching device 16, and the vertical axis represents the output value of the inertial reference device 14 of the moving body 12. At this time, if the number of shaking input values is increased and a large number of output values corresponding thereto are measured to obtain a straight line of the output value by the least squares method, the value of the reference output value (the straight line of the output value of the reference inertial reference device) By calculating the difference value, the scale factor Kh and the drift rate bias Dh of the inertial reference device 13 of the moving body 12 are obtained by the following equations. Kh = [(Δα'-γ ') / β] × 100 (%) ----- (1) Dh = γ' / T (degrees / hour), where T is the measurement time, ----- (2) The relative angle between the coordinate systems between the two inertial reference devices 14 and 20, in other words, the initial value of the coordinate system of the inertial reference devices 14 of the moving body 12 is known as the physical angle between the inertial reference devices 14 and 20. In this case, the known value can be introduced to easily set the coordinate initial value of the inertial reference device 20 of the launching device 16 on the reference side. When the physical angle has an unknown value, it can be obtained by another initial value setting method, for example, a method using GPS.

The second shown in FIGS. 4A and 4B and FIG.
With reference to the embodiment of FIG. 1, the mobile base 30 is, for example, a missile launch ship, and the mobile base 32 is a missile body that is launched into the air from a launcher 36, which is a missile launch tower provided in the base body 30. , Has an inertia reference device 34 inside. The moving mother body 30 has its own inertia reference device 38 installed in the central portion of the ship body, and the front of the front-rear axis is set as the X-axis.

In the above-mentioned structure, the inertia reference device 38 of the moving mother body 30 is provided as a reference inertia reference device, and its accuracy is determined by external information such as a navigation satellite (GP).
S), it is maintained from the measurement data of the current position by astronomical measurement. The moving body 32 exists in the launching device 36 immediately before launching, and its inertia reference device 34 due to deformation of the moving mother body 30 or the like.
When the relative angle change between the inertial reference device 38 of the moving mother body 30 that serves as a calibration reference and the calibration reference cannot be ignored in the mission,
Other means, for example, an optical means such as a collimator may always be used for measurement, and a correction value may be input and used during calibration.

When attempting to calibrate the gyro scale factor and drift rate bias of the inertial reference device 32 of the moving body 30, the moving body 30 itself is
For example, it is swayed by a rolling operation or the like so that positive and negative angle inputs are applied to the inertial reference device 38 of the calibration reference and the inertial reference device 34 of the moving body 32, and the difference between the values of the output, for example, the amount of electricity. If a difference value is found, the inertia reference device 38 for calibration reference is always maintained in accuracy, so that the scale factor changes and drifts in the inertia reference device 34 of the moving body 32 immediately after the difference value. The rate bias can be calculated and detected, and the detected value is applied as a correction value to the calibration value at the time of the previous calibration and updated to calibrate the current scale factor and bias value.
It can be set.

FIG. 5 is a graphical representation of the calculation and detection method of the scale factor and bias value according to the above-described configuration and setting process, and the scale factor is shown as ΔK and the drift bias is shown as D. .
That is, when the shaking input of the moving mother 30 is applied,
The inertia reference device 38 of the same body detects various values with the angle input (± β) of the launching device 36 corresponding to the shaking input as a reference input, and at this time, the moving body 32 corresponding to each detected value.
The output value of the inertia reference device 34 is measured, and the output straight line obtained by the least squares method from the multipoint measurement values is calculated. The output straight line and the output straight line of the calibration reference inertia reference device 38 are shown in FIG. As shown, ΔK = [(Δα′−γ ′) / β] × 100 (%) −−− (3) D = γ ′ / T (degree / hour), T is the measurement time, and −−− (4 ) Can be obtained as

In the present embodiment, even if the physical relative angle (two axes) between the inertia reference device of the moving body and the inertia reference device of the moving body, which is different from the angle around the axis to which the shaking input is mainly applied, is unknown. The initial values of the two axes can be set.

[0021]

As is apparent from the above description, when the calibration and setting method according to the present invention is applied, for example, when the moving body is a torpedo, sound waves are emitted while moving in a circle in the search mode. Usually, it rotates several times to several tens of times in the same direction, so when a strapdown type inertial reference device is generally used, the influence of the gyro scale factor error becomes large.
By applying the calibration method according to the present invention at the time of launch to calibrate the scale factor and drift bias of the inertial reference device, the effect of improving the heading and position accuracy in the inertial reference device of the moving body is large, and thus the command input When the moving body is moved toward a predetermined target by application, the accuracy of arrival of the moving body at the target position can be improved.

Further, according to the present invention, since a relatively short time immediately before the start of the movement of the moving body is captured and the calibration processing is performed, the initial scale factor and the bias value can be updated to move the moving body. There is an effect that the arrival accuracy can be improved in a shorter time than in the past and based on a certain simple arithmetic process. Also, in the method of oscillating the launching device to obtain the sway input, the inertial reference device of the moving body can be used irrespective of the large moving body, and the initial calibration of the scale factor and the bias can be performed, which simplifies the calibration operation itself. Is effective. Further, by using the rotation around the azimuth axis, the initial values of the two axes of the horizontal plane can be set even if the physical relative angle of the horizontal plane between the torpedo or a moving body such as a missile and the inertial reference device for the calibration reference is not known. .

[Brief description of drawings]

FIG. 1 is a plan view illustrating a case where the method of the present invention is applied to an embodiment in which a ship is a moving base and a torpedo is a moving body.

FIG. 2 is a partially enlarged explanatory view showing the calibration of the calibration means in the flight preparation state of the moving body in the embodiment.

FIG. 3 is a graph showing a relationship between an input and an output of the inertial reference device.

FIG. 4A is a perspective view showing another embodiment to which the calibration method of the present invention is applied. (B) is a partially enlarged view of the same embodiment.

FIG. 5 is a graph similar to FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Movable body 12 ... Movable body 14 ... Movable body inertial reference device 16 ... Ejecting device 18 ... Movable body inertial reference device 20 ... Ejection device 30 ... Movable mother body 32 ... Movable body 34 ... Movable body inertial reference device 36 ... Launching device 38 ... Inertia reference device for moving mother

Claims (2)

[Claims] 1. A method for calibrating an initial scale factor and a bias of an inertial reference device included in a moving body mounted on, and flying from, a moving mother body, comprising: The inertial reference device for reference is previously mounted on the means, and the scale factor and bias of the reference inertial reference device are constantly corrected in accordance with the correct value of the inertial reference device included in the moving mother body, and the flight launch is performed. A predetermined shaking input is applied to the means, the shaking input is measured by the reference inertial reference device, and an output value corresponding to the measured input is obtained as a reference output value. At the same time, the inertial reference device of the moving body is provided. An output value is measured as a calibrated output value, and a scale factor and a bias of the inertial reference device of the moving body are obtained by obtaining a difference value between the reference output value and the calibrated output value. Calibration method for inertial reference unit being characterized in that so as to correct. 2. A method for calibrating a scale factor and a bias of an inertial reference device included in a moving body mounted on, and flying from, a moving mother body, wherein the inertial reference device included in the moving mother body is used as a reference inertia. As a reference device, a predetermined shaking input is given to the moving mother body, the shaking input is measured by the reference inertial reference device, and an output value corresponding to the measured input is obtained as a reference output value. An output value of the inertial reference device provided is measured as a calibrated output value, and a difference value between the reference output value and the calibrated output value is obtained to correct a scale factor and a bias of the inertial reference device of the moving body. A method for calibrating an inertial reference device characterized in that