JP3037516B2 - Direction measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention accurately corrects an error caused by deformation of a structure to which a sensor is attached when detecting an orientation of a target by a sensor, and accurately detects the orientation of the target. The present invention relates to an azimuth measuring device capable of performing such operations.

[0002]

2. Description of the Related Art FIG. 9 is a conceptual configuration diagram showing the concept of a conventional strap-down system shown in "Introduction to Guidance Weapons" issued by the Defense Technology Association. In FIG. Table with rigidly connected sensors, 5
Reference numeral 4 denotes an accelerometer rigidly connected to the table 53 to detect an acceleration applied to the table, and reference numeral 55 denotes an angular velocity meter similarly rigidly connected to the table 53 to detect an angular velocity of the table 53, and includes three rate gyros 55a and 55b. , 55c.

Reference numeral 56 denotes an arithmetic unit for processing detection signals from the accelerometer 54 and the gyro 55.

[0004] In this strap-down system, errors are corrected by a gimbal and a servomotor, and all other operations are performed by an electronic computer.

That is, in this strap-down system, three rate gyros 55a, 55b, 55c and an accelerometer 54 are fixed to a table 53 which is a direct moving body, and the three rate gyros 55a, 55b, 5
Based on the posture angle of the moving body detected by 5c, the arithmetic unit 56 creates a stable reference board at that time, and adds the acceleration information from the accelerometer 54 to calculate the position and posture of the moving body. ing.

When the optical sensor is attached to the table 53, the accelerometer 54 and the gyro 55 detect momentarily acceleration data and angular velocity data applied to the optical sensor attached to the table 53. On the other hand, when the arithmetic unit 56 performs calculations such as integration and coordinate conversion, the displacement and rotation of the table 53, that is, the optical sensor at each time can be known.

Therefore, when the optical sensor is attached to the wing tip of a flexible structure in an airplane and the wing tip is bent or twisted, the optical sensor attached to the wing tip in the inertial coordinate measuring system. , The displacement and the rotation amount can be detected.

Further, the displacement and the displacement of the fuselage of the aircraft in the inertial coordinate system by the strap down method described above.
Since the amount of rotation can be calculated, the amount of displacement and rotation of the wing tip with respect to the fuselage can be obtained by calculating the relative amount of the wing tip with respect to the displacement and the amount of rotation.

Then, the observation value of the azimuth with respect to the target by the optical sensor is converted into a coordinate using the displacement / rotation amount, and an error in detecting the azimuth of the target due to the displacement / rotation of the optical sensor is calibrated. It is possible to accurately calculate and obtain the azimuth of the target in a state where there is no displacement or rotation of the sensor.

[0010]

Since the conventional azimuth measuring device is constructed as described above, it is necessary to attach additional precision equipment such as the accelerometer 54 and the angular velocity meter 55 to the wing tip of the aircraft. However, it is disadvantageous in terms of volume, weight, durability and the like, and there is a problem that the cost is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and the invention of claim 1 is applicable to a rigid structure of an aircraft without using precision equipment such as an accelerometer and an angular velocity meter. From the relationship between the mounted reference light emitter and the sensor mounted on the flexible structure of the aircraft,
By estimating the amount of structural deformation on the structural model of the flexible structure to which the sensor is attached, the error associated with the azimuth measurement of the target is calibrated based on this, and the above estimation results and the calibrated target are calibrated. It is an object of the present invention to obtain an azimuth measuring device capable of displaying the azimuth measurement result and the like.

According to the second aspect of the present invention, the relationship between a reference point attached to a rigid structure and a sensor attached to a flexible structure is based on a structural model of the flexible structure to which the sensor is attached. It is an object of the present invention to obtain an azimuth measuring device capable of calibrating an error accompanying the azimuth measurement of a target object without using an accelerometer or an gyro by estimating a structural deformation amount.

[0013]

According to a first aspect of the present invention, there is provided an azimuth measuring apparatus, comprising: a reference illuminator mounted on a rigid structure of an aircraft; and an azimuth of the reference illuminator mounted on a flexible structure of the aircraft. A sensor that detects data and target direction data of the target, and is stored in advance based on a deviation between the direction data of the reference light emitting device detected by the sensor and the reference direction data of the reference light emitting device previously determined. Means for estimating the amount of structural deformation on the structural model of the flexible structural part of the aircraft, and measuring the orientation of the target based on the amount of structural deformation estimated by the means for estimating the structural deformation. Calibration means for calibrating the accompanying error, and display for displaying the estimation result by the structural deformation amount estimation means and the azimuth measurement result of the target calibrated by the calibration means It is that a stage.

The azimuth measuring device according to the second aspect of the present invention comprises a sensor attached to a flexible structure for detecting azimuth data of a reference point and azimuth data of a target placed on a rigid structure, and the sensor. A structure for estimating a structural deformation amount on a structural model of the flexible structure stored in advance based on a deviation between the detected azimuth data of the reference point and the previously obtained reference azimuth data of the reference point. Deformation amount estimating means, and calibration means for calibrating an error of azimuth data due to deformation of the flexible structure accompanying azimuth measurement of the target based on the structural deformation amount estimated by the structural deformation amount estimating means. It is.

[0015]

According to the first aspect of the present invention, the azimuth measuring device comprises:
Reference illuminator attached to a rigid structure in an aircraft, orientation data of a reference illuminator detected by a sensor attached to a flexible structure in an aircraft, and reference orientation data for the reference illuminant previously determined Estimate the amount of structural deformation on the structural model of the flexible structure of the aircraft stored in advance on the basis of the deviation, and measure the orientation of the target caused by the deformation of the flexible structure based on the amount of structural deformation. And corrects the azimuth data error of the target object, accurately measures the azimuth of the target object, and displays the estimation result, the directional measurement result of the calibrated target object, and the like.

According to a second aspect of the present invention, there is provided an azimuth measuring device, comprising: azimuth data of an arrangement or a reference point on a rigid structure detected by a sensor attached to a flexible structure; Estimate the amount of structural deformation on the structural model of the flexible structure stored in advance based on the deviation from the data, and measure the orientation of the target object caused by the deformation of the flexible structure based on the amount of structural deformation. At this time, the error of the azimuth data of the target is calibrated to accurately measure the azimuth of the target.

[0017]

【Example】

Embodiment 1 FIG. Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes an aircraft, and reference numeral 2 denotes a reference light emitter attached to the fuselage of the aircraft 1.

In this case, the fuselage of the aircraft 1 to which the reference light emitter 2 is attached is regarded as a rigid structure.

Reference numeral 3 denotes an optical sensor attached to the wing tip of the aircraft 11. In this case, the wing of the aircraft 1 to which the optical sensor 3 is attached is regarded as a flexible structure that bends or twists due to a load applied to the wing surface during flight.

An arithmetic unit 4 for processing a signal output from the optical sensor 3 (structure deformation amount estimating means, calibration means)
And a numerical model of the wing structure to which the optical sensor 3 is attached is stored. Reference numeral 5 denotes a display device (display means) provided in the cockpit for displaying a result of calculation by the calculation device 4 and the like.

Reference numeral 6 denotes a target to be measured, which indicates another aircraft.

FIG. 2 shows an optical sensor 3 attached to a wing tip, which is a flexible structure, due to the wing of the aircraft 1 being bent or twisted.
FIG. 4 is an explanatory diagram showing an azimuth angle ψ and an elevation angle θ in a coordinate system of a wing tip when displacement and rotation occur in the wing tip.

FIG. 3 shows the relationship between the coordinate system of the wing tip when the optical sensor 3 attached to the wing tip, which is a flexible structure, is displaced / rotated and when it is not displaced / rotated. FIG.

FIG. 4 is a conceptual diagram showing the relationship between the deflection and torsion of the wing tip to which the optical sensor 3 is attached.

When examining the displacement and rotation of the optical sensor 3 due to the wings of the aircraft 1 being bent or twisted,
It is sufficient to consider only the displacement in the z direction and the rotation around the x axis and the y axis.

This is because the wing of the aircraft 1 can be handled as a substantially rectangular flat plate.

Here, the displacement in the z direction due to the wing of the aircraft 1 being bent or twisted is represented by Δz, and the rotation angles about the x axis and the y axis are represented by ΔX and ΔY, respectively. In addition, the order of coordinate conversion is assumed to be Δz based on a coordinate system in the case where there is no displacement / rotation, and estimation is performed in the order of ΔX and ΔY.

By the way, the coordinates (xro, iro, zro) of the reference light emitting device 2 in the coordinate system without displacement and rotation shown in FIG. 3, that is, the coordinate system xo-yo-zo, and the displacement and rotation occur. There is a relationship expressed by the following equation between the coordinate (xr, yr, zr) of the reference light emitting device 2 in the coordinate system xyz at that time.

[0029]

(Equation 1)

Here, the coordinates (xr
o, yro, zro) are known and Δz, ΔX, ΔY
And coordinates (xr, yr, zr) are unknown.

Therefore, assuming Δz first, the above (1)
Based on the formula and the azimuth angle ψ and the elevation angle θ obtained by observing the reference light emitting device 2 with the optical sensor 3, estimation is further performed in the order of ΔX and ΔY, and the optimum Δz, ΔX,
ΔY is obtained, and an error caused by displacement / rotation generated in the optical sensor 3 attached to the wing tip, which is a flexible structure portion, when measuring the azimuth of the target is calibrated to perform accurate azimuth measurement of the target. .

The optimum Δz, ΔX, Δ described above with reference to FIG.
The calculation procedure for obtaining Y will be described.

FIG. 5 is a flowchart for explaining the calculation procedure of Δz, ΔX, and ΔY.

In FIG. 5, first, a displacement Δz in the z direction is assumed (step ST1).

Next, a rotation angle ΔX about the x-axis is estimated from the model of the wing structure stored in advance in the arithmetic unit 4 using Δz assumed in step ST1 (step ST2).

The estimation of the rotation angle ΔX about the x-axis is performed as follows.

That is, FIG. 4 shows a simple wing structure model.
Considering a uniform beam to which a uniform load ω is applied as shown in (1), the displacement Δz and the inclination ΔX of the free end are represented by the following equations.

[0038]

(Equation 2)

Where l: beam length, E: Young's modulus, I:
This is the second moment of area.

Therefore, the following relationship is established between the free end displacement Δz and the inclination ΔX using the constant α.

[0041]

(Equation 3)

As a result, the rotation angle ΔX about the x-axis can be estimated using Δz.

Next, the process proceeds to step ST3, in which yr is obtained by substituting Δz and ΔX into the following equation (1) in the second row (step ST3).

[0044]

(Equation 4)

Next, xr and zr are obtained from the azimuth angle ψ and the elevation angle θ obtained by observing the reference light emitter 2 by the optical sensor 3 in the coordinate system xyz shown in FIG. 2 (step ST4). .

From the azimuth angle ψ and the elevation angle θ, xr and zr are obtained as follows.

That is, the azimuth angle ψ and the elevation angle θ are represented by the following equations using the coordinates (xr, yr, zr).

[0048]

(Equation 5)

[0049]

(Equation 6)

The azimuth angle ψ is calculated based on the output of the optical sensor 3.
Further, since yr has been clarified in step ST3, xr can be calculated from equation (5), and the calculated xr
Zr can be calculated from Expression (6) using the above, yr, and the elevation angle θ.

Next, Δ Δ assumed in step ST1
Find the optimal value of z (step ST5, step ST5)
6).

The method for obtaining the optimum value of Δz is performed as follows.

That is, in equation (1), the unknown ΔY is included in the equation on the first row for xr and 3 for zr.
Since this is the expression on the line, this part is cut out as shown below.

[0054]

(Equation 7)

The only difference between the vector on the left side of the equation (7) and the vector on the right end of the right side is the rotation conversion of the rotation angle ΔY about the y-axis. That is, the lengths of both vectors must be the same.

However, in step ST1, since the calculation has been proceeded by appropriately assuming Δz, the lengths of the two vectors usually do not match.

FIG. 6 shows the relationship between Δz assumed in step ST1 and the difference in length between the two vectors.

In FIG. 6, the vertical axis represents the length error (%) between the two vectors, and the horizontal axis represents the assumed value of Δz.

As is apparent from FIG. 6, when Δz is 0.5, the length error (%) of both vectors is zero, and the value at this time is the optimum assumed value of Δz. Therefore, in order to obtain the optimal assumed value Δz, iterative calculation is performed using the assumed Δz, the length error (%) between the two vectors is obtained, and the length error (%) between the two vectors is sufficiently small. It suffices to find Δz such that Δ thus determined
It is appropriate to use z as a true value.

ΔY is calculated from Δz by using equation (7).

As a result, a displacement Δz in the z-axis direction, a rotation angle ΔX in the x-axis direction, and a rotation angle ΔY in the y-axis direction are obtained (step ST7).

The displacement Δz in the z-axis direction, the rotation angle ΔX in the x-axis direction, and the rotation angle ΔY in the y-axis direction thus obtained.
Is the calibration data when measuring the orientation of the target, so that when measuring the orientation of the target using this calibration data, the optical sensor 3 may be bent or twisted by the wing on which the optical sensor is mounted. An error due to displacement, rotation, and the like generated when the target is observed is calibrated to accurately measure the azimuth of the target.

Further, the displacement Δz in the z-axis direction, the rotation angle ΔX in the x-axis direction, the rotation angle ΔY in the y-axis direction, and the accurate position of the target calibrated by using these constituent data are obtained. The direction is displayed on the display 5.

Embodiment 2 FIG. In the first embodiment, the case of an aircraft has been described. However, a flexible boom is connected to a main body of a rigid structure on which a reference point is attached, and the direction data of the reference point and the direction data of a target are detected. The present invention can also be applied to an artificial satellite having a sensor attached to the end of the boom.

FIG. 7 is an explanatory diagram of the second embodiment.
Reference numeral 1 denotes a reference point attached to the rigid satellite body 14. The reference point 11 may be a visible light emitter, an infrared light emitter, an ultraviolet light emitter, or the like.

Reference numeral 12 denotes a sensor attached to the tip of the flexible boom 15, which may be a detector for visible light, infrared light, ultraviolet light, or the like.

Reference numeral 13 denotes an arithmetic unit (structural deformation amount estimating means, calibrating means) attached to the artificial satellite body 14.

The operation of the azimuth measuring device thus configured is the same as that already described in the first embodiment, and a description thereof will be omitted.

Embodiment 3 FIG. In the first and second embodiments, the reference light emitting device or the reference point is attached to the rigid structure. However, as shown in FIG. It can also be used as a reference point.

Embodiment 4 FIG. In the first embodiment, the displacement Δz in the z-axis direction, the rotation angle ΔX in the x-axis direction, and the rotation angle Δ in the y-axis direction
Although the accurate orientation of the target object calibrated using Y and these calibration data is configured to be displayed on the display 5, the displacement Δz in the z-axis direction, the rotation angle ΔX in the x-axis direction, and the rotation angle ΔX in the y-axis direction The rotation angle ΔY and the like may be input to the next processing device without being displayed on the display 5.

[0071]

As described above, according to the first aspect of the present invention, the sensor is attached to the flexible structure of the aircraft, and the displacement of the sensor due to the bending or twisting of the flexible structure causes the displacement of the target object. Even in a state where the azimuth measurement cannot be performed accurately, the azimuth data of the reference illuminator detected by the sensor and the azimuth data of the reference illuminant with respect to the reference illuminant previously determined are stored in advance based on the deviation. Estimate the amount of structural deformation on the structural model of the flexible structure of the aircraft, and calculate the azimuth data of the target at the time of measuring the azimuth of the target caused by the deformation of the flexible structure based on the amount of structural deformation. Since the error can be calibrated, the direction of the target can be measured accurately,
Further, there is an effect that the estimation result, the azimuth measurement result of the calibrated target object, and the like can be displayed. In addition, there is no need to use precision instruments such as an accelerometer and an angular velocity meter, so that there is an advantage in terms of volume, weight, durability and the like.

According to the second aspect of the present invention, the sensor is attached to the flexible structure, and the azimuth measurement of the target can be accurately performed by the displacement of the sensor position due to the bending or twisting of the flexible structure. Even in a state where it is not possible, based on the deviation between the azimuth data of the reference point arranged on the rigid structure detected by the sensor attached to the flexible structure and the reference azimuth data of the reference point previously determined. Estimates the amount of structural deformation on the structural model of the flexible structure stored in advance in the structure, and based on the amount of structural deformation, the orientation of the target when measuring the orientation of the target caused by the deformation of the flexible structure This has the effect of calibrating the data error and accurately measuring the azimuth of the target. In addition, there is no need to use precision instruments such as an accelerometer and an angular velocity meter, so that there is an advantage in terms of volume, weight, durability and the like.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an azimuth measuring device according to a first embodiment of the present invention.

FIG. 2 shows the azimuth angle ψ and the elevation in the coordinate system of the wing tip when the wing of the aircraft is bent or twisted and the optical sensor attached to the wing tip, which is a flexible structure, is displaced or rotated. FIG. 4 is an explanatory diagram showing an angle θ.

FIG. 3 is an explanatory diagram showing a relationship between a blade tip coordinate system when a displacement / rotation occurs and a displacement / rotation does not occur in an optical sensor attached to a wing tip which is a flexible structure.

FIG. 4 is a conceptual diagram showing the relationship between the deflection and torsion of a wing tip to which an optical sensor is attached.

FIG. 5 is a flowchart for explaining a calculation procedure of Δz, ΔX, and ΔY.

FIG. 6 is a characteristic diagram illustrating a relationship between a length error (%) between a vector on the left side and a vector on the right end of the right side of Equation (4) and an assumed value of Δz.

FIG. 7 is a conceptual diagram showing an azimuth measuring device according to a second embodiment of the present invention.

FIG. 8 is a conceptual diagram showing an azimuth measuring device according to Embodiment 3 of the present invention.

[Figure 9] "Introduction to guided weapons" issued by Japan Defense Technology Association
1 is a conceptual configuration diagram showing the concept of the conventional strap-down method shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Aircraft 2 Reference light emitter 3 Optical sensor (sensor) 4,13 Computing device (structural deformation amount estimation means, calibration means) 5 Display device (display means) 11 Reference point 12 Sensor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01C 21/00

Claims (2)

(57) [Claims] 1. A reference illuminator mounted on a rigid structure of an aircraft, a sensor mounted on a flexible structure of the aircraft for detecting azimuth data of the reference illuminator and target azimuth data of a target, and the sensor Structural deformation on the structural model of the flexible structural part of the aircraft stored in advance based on the deviation between the azimuth data of the reference illuminator detected by the method and the previously obtained reference azimuth data of the reference illuminator Structural deformation amount estimating means for estimating the amount, calibration means for calibrating the error accompanying the azimuth measurement of the target based on the structural deformation amount estimated by the structural deformation amount estimating means, and estimation by the structural deformation amount estimating means An azimuth measuring device comprising: display means for displaying a result, an azimuth measurement result of a target calibrated by the calibration means, and the like. 2. A sensor disposed on a flexible structure for detecting azimuth data of a reference point disposed on a rigid structure or azimuth data of a target, and azimuth data of the reference point detected by the sensor and the azimuth data of the reference point. A structural deformation amount estimating means for estimating a structural deformation amount on a structural model of the flexible structure stored in advance on the basis of the deviation of the reference point from the reference azimuth data obtained, and the structural deformation amount A calibration unit configured to calibrate an error accompanying the measurement of the orientation of the target based on the structural deformation amount estimated by the estimation unit.