JP3298343B2 - Calibration device for wind tunnel balance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for calibrating a wind tunnel balance used for wind tunnel experiments on an aircraft model.

[0002]

2. Description of the Related Art A wind tunnel balance is installed near the center of gravity of an aircraft model and measures forces and moments acting on the aircraft model. Conventionally, calibration of this type of wind tunnel balance is performed by suspending a weight from the calibration device main body, applying a predetermined force or moment to the calibration device main body, and measuring the output from the wind tunnel balance at that time.

[0003]

However, in the above-described conventional calibration method, when a force or moment is applied to the calibration device main body by a weight, the relative positional relationship between the wind tunnel balance and the calibration device main body is shifted. Therefore, assuming an experiment in which a force and a moment are applied to the aircraft model while maintaining the positional relationship between the wind tunnel balance and the aircraft model at a predetermined value, the calibration conditions may be different from those in the experiment, and highly accurate calibration may not be performed.

An object of the present invention is to detect a displacement of a carry body when a force for calibration is applied to the wind tunnel balance via the carry body, and to detect a displacement of the carry body with one end of the wind tunnel balance, the carrying frame, It is an object of the present invention to provide a wind tunnel balance calibration device capable of performing calibration while maintaining the relative position of the wind tunnel balance within a predetermined range.

[0005]

According to the present invention, there is provided an apparatus for calibrating a wind tunnel balance, comprising: a sting mounting frame to which one end of the wind tunnel balance is connected via a sting; a carry body into which the other end of the wind tunnel balance is inserted; X, Y,
Force in the Z-axis direction and moments Mx, M around these axes
a load mechanism for providing y and Mz; displacement detecting means for detecting displacement of the carry body; and moving the sting mounting frame in the X, Y, and Z directions relative to the carry body, and moving around the axes. A rotating restoration mechanism,
When the load body drives the carry body, the displacement amounts of the sting mounting frame in the X, Y, and Z directions with respect to the carry body and the displacement angles around these axes are determined based on the output of the displacement detection means. The above object is achieved by providing a control means for controlling the restoring mechanism so as to fall within a predetermined range.

[0006]

The load mechanism applies forces in the X, Y, and Z-axis directions and moments Mx, My, and Mz around these axes to the carry body in which the other end of the wind tunnel balance is inserted. This allows
The wind tunnel balance is provided with forces and moments for calibration. At this time, the displacement detecting means detects the displacement of the carry body. The control means controls the restoring mechanism based on the output of the displacement detecting means so that the displacement amounts of the sting mounting frame in the X, Y, and Z directions with respect to the carry body and the displacement angles around these axes fall within predetermined ranges. Control.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. First, in this specification, as shown in FIG. 8, the forces and moments acting on the aircraft model 100 are defined. Therefore, in FIG. 1, the right direction is the positive X direction Fx (+), the left direction is the negative X direction Fx (-), and the downward direction is the positive Y direction Fy.
(+), The upward direction is the Y negative direction Fy (−). In FIG. 2, the downward direction is the Z positive direction Fz (+), and the upward direction is the Z direction.
The negative direction Fz (-), the left direction is the Y positive direction Fy (+), and the right direction is the Y negative direction Fy (-).

In FIGS. 1 and 2, reference numeral 21 denotes a sting mounting frame, 22 denotes a carry body, 23 denotes a sting, and 23A denotes a wind tunnel balance. One end of the sting 23 is fixed to the sting mounting frame 21 by a cylindrical connecting portion 23a, and one end of the wind tunnel balance 23A is fixed to the other end. The other end of the wind tunnel balance 23A is inserted into the carry body 22. Since the other end of the wind tunnel balance 23A inserted into the carry body 22 is fixed to the carry body 22, the detection unit of the wind tunnel balance 23A is displaced relative to the carry body 22 according to the posture of the carry body 22, A detection signal corresponding to a force or a moment acting on the carry body 22 is output.
The force in the Y and Z axis directions and the moment around each axis can be detected.

The sting mounting frame 21 is mounted on the base 2.
4, Z-direction restoration jacks 31a, 31b, 3
1c, the posture is controlled so that the position in the Z direction can be adjusted.
The posture is controlled so that the position in the X direction can be adjusted by the X-direction restoration jack 32 installed on the base 4, and the posture is controlled so that the position in the Y direction can be adjusted by the Y-direction restoration jacks 33 a and 33 b installed on the base 24. . Each restoration jack is a universal joint 34a
The sting attachment frame 21 can be displaced in the X, Y, and Z-axis directions, and can be displaced around each axis through .about.34f.

In FIG. 2, the restoration jack 31a is not shown. The universal joint 34a is not shown in any of FIGS. 1 and 2.

As shown in FIG. 3, the carry body 2
2 is connected to load jacks 1 to 16 by a piano wire 35 and a connecting rod 36 to generate various loads. The load jacks 1 and 2 load the carry body 22 in the negative Z direction, and the load jacks 3 and 4 load the carry body 22 in the positive Z direction. Load jacks 5 and 6 carry body 2 in the positive X direction.
2, the load jacks 7, 8 load the carry body 22 in the negative X direction. The load jacks 9 and 10 load the carry body 22 in the positive Y direction, and the load jacks 11 and 12
Loads the carry body 22 in the Y negative direction. By selectively operating the load jacks 1 to 16 as shown in FIG.
A force in the Y and Z axis directions and a moment about each axis can be given. 2, reference numerals 58a to 58f denote load cells for measuring the axial force of the connecting rod 36. Further, although not shown, the axial force of the piano wire 35 is also indicated by a load cell (shown by reference numerals 59a to 59h in FIG. 9). ) And is input to a control circuit 61 described later.

1 and 2, a piano wire 35 having one end connected to a load jack extending in the horizontal direction is connected to the carry body 22 through a circular hole 37 formed in the mounting frame 21. Even if the posture of 22 changes, any piano wire 35 is prevented from contacting the mounting frame 21.

In FIGS. 1 and 2, reference numeral 41 denotes a column connecting the lower base 24 and the upper frame 25. As shown in FIGS. 5 and 6, the column 41 has a displacement sensor mounting frame 42 attached thereto. Installed. This mounting frame 4
2, a displacement sensor mounting shaft 43 includes a vertical adjustment nut 4;
4, a displacement measuring device 51 for measuring various displacements of the carry body 22 is provided at the tip (the lower end in FIGS. 5 and 6) of the shaft 43. A target plate 53 is connected to the upper surface of the target mounting arm 52 fixed to the upper surface of the carry body 22,
As shown schematically in FIG. 7, each tip of each of the displacement sensors 51 a to 51 f of the displacement measuring device 51 engages with the target plate 53, and each of the displacement sensors 51 a to 51 f displaces the carry body 22 in the X direction. , Y direction displacement,
A displacement signal according to the Z-direction displacement is output.

FIG. 9 is a block diagram of a wind tunnel balance calibrating device. A calibration signal is inputted from an operation unit 62 to a control circuit 61 including a microcomputer or the like. The calibration signal is given to the wind tunnel balance 23A through the carry body 22 by X,
It indicates the force in the Y and Z axis directions and the moment about each axis, and can be input from, for example, a keyboard.
The operation unit 62 is not limited to a keyboard, and various types such as a dial type can be used. Control circuit 61
Are load jacks 1 to 16 according to the input calibration signal.
Is selectively driven to apply a desired force or moment to the carry body 22. The control circuit 61 includes a displacement measuring device 51.
The displacement signals of the displacement sensors 51a to 51f are input, and the restoration jack is selectively driven in accordance with the displacement signals so that the centers of the carry body 22 and the wind tunnel balance 23A substantially coincide with each other. The attitude of the wind tunnel balance mounting frame 21 is controlled so that the displacement angle about the axis becomes substantially zero. Further, the control circuit 61 includes the load cells 58a to 58f described above and a load cell 58 not shown in FIG.
The load signal of the rod 36 detected by g and 58h, the detection signal from the wind tunnel balance 23A, and the load signal of the rod 35 detected by the load cells 59a to 59h not shown in FIG.

The operation of the thus configured wind tunnel balance calibration device will be described. FIG. 10 shows an example of a processing procedure of a program executed by the control circuit 61. In step S1, a calibration signal is read, and in step S2, a signal for driving a load jack is output according to the read calibration signal. As a result, a force or moment corresponding to the calibration signal acts on the carry body 22, and the carry body 22 takes a posture corresponding thereto. For example, when a calibration signal for applying a force of Fx in the positive X direction to the carry body 22 is input, the load jacks 5 and 6 drive the carry body 22 until the load signal from the load cell connected thereto becomes Fx.
When other forces in the axial direction and moments around each axis are given by the calibration signal, the load jacks are similarly applied until the force of each axis and the moment around each axis reach a desired value by the load signal from each load cell. Drive. Then, the displacement signal is read in step S3, and the restoration amount of the mounting frame 21 is calculated from the displacement signal in step S4.

As will be described later, this restoration amount includes a displacement amount X in the X direction, a displacement amount Y in the Y direction, a displacement amount Z in the Z direction, a displacement angle φ with respect to the X axis, a displacement angle θ with respect to the Y axis, and a displacement angle with respect to the Z axis. It is represented by ψ. Next, in step S5, the driving amount of the restoration jack is calculated based on the calculated restoration amount, the restoration jack is gradually displaced, and the mounting frame 21 is moved by the restoration amount calculated in step S4.
For example, the displacement calculated from the displacement signal is divided into n equal parts,
It is desirable to perform control such that a ramp wave having a 1 / n displacement amount is output to the restoration jack n times and the frame 21 is restored little by little.

Let the coordinates of the center of the wind tunnel balance be P (X, Y, Z)
And the detection signals of the displacement sensors 51a to 51f are xa, y
Let a, yb, za, zb, zc be the detection signals at the start of the measurement, respectively, and assume that the coordinates P at the center of the wind tunnel balance are P
(X, Y, Z) is

## EQU1 ## X direction displacement: X = xa Y direction displacement: Y = (ya + yb) / 2 Z direction displacement: Z = (za + zb + zc) / 3 The displacement angle with respect to each axis is

## EQU2 ## Displacement angle with respect to X axis: φ = tan ^-1 {(zb-zc) / L1} Displacement angle with respect to Y axis: θ = tan ^-1 {-(za + zb + zc) / 2L2} Displacement angle with respect to Z axis: ψ = Tan ^-1 {(ya-yb) / L2}. Note that L1 is as shown in FIG.
Similarly, the distance L2 between the displacement sensor 51b for detecting the displacement ya and the displacement sensor 51c for detecting the displacement yb is the displacement z.
This is the distance between the displacement sensor 51e that detects b and the displacement sensor 51f that detects the displacement zc.

Finally, in step S6, the wind tunnel balance 2
The output from 3A is read, the output is stored in association with the calibration signal given in step S1, and calibration is performed. By such control, during the calibration operation, the center of the wind tunnel balance 23A substantially coincides with the center of the carry body 22 in the X, Y, and Z axis directions, and the relative rotation angles of the two are substantially zero in the Mx, My, and Mz moment directions. Becomes Therefore, calibration can be performed under the same conditions as when mounted on an aircraft model in an actual wind tunnel experiment, and highly reliable calibration can be performed.

[0019]

As described above, according to the present invention, the forces in the X, Y and Z-axis directions and the forces around these axes are applied to the carry body in which the other end of the wind tunnel balance is inserted so that the balance center can be relatively displaced. When moments Mx, My and Mz are applied, one end of the wind tunnel balance detects the displacement of the sting mounting frame, which is fixed via the sting, and the relative displacement between the frame and the carry body becomes a predetermined range, preferably substantially zero. Since the position of the frame is controlled as described above, calibration equivalent to mounting the wind tunnel balance on an aircraft model in an actual wind tunnel experiment can be performed, and highly reliable calibration can be performed.

[Brief description of the drawings]

FIG. 1 is a plan view of a wind tunnel balance calibration device according to the present invention.

FIG. 2 is a side view of the wind tunnel balance calibration device shown in FIG. 1 as viewed from a direction II.

FIG. 3 is a perspective view illustrating an arrangement of a load jack shown in FIG. 1;

FIG. 4 is a diagram showing the operation of the load jack and the load direction at that time.

5 is a view showing a displacement measuring device attached to the wind tunnel balance device of FIG. 1, and is a side view as viewed from a direction V in FIG. 1;

FIG. 6 is a side view of the displacement measuring device of FIG.

FIG. 7 is a perspective view schematically showing the displacement measuring device of FIGS. 5 and 6;

FIG. 8 is a diagram illustrating loads acting on an aircraft model.

FIG. 9 is a block diagram of a wind tunnel balance calibration device according to the present invention.

FIG. 10 is a flowchart illustrating an example of a processing procedure of a program executed by the control circuit of FIG. 9;

[Explanation of symbols]

 1-16 Load jack 21 Sting mounting frame 22 Carry body 23 Sting 23A Wind tunnel balance 31a-31c Z-direction restoration jack 32a X-direction restoration jack 33a, 33b Y-direction restoration jack 34a-34f Universal joint 35 Piano wire 36 Connecting rod 42 Displacement measurement Device mounting frame 43 Displacement measuring device mounting shaft 51 Displacement measuring device 51a to 51f Displacement sensor 52 Target mounting arm 53 Target

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01M 9/06 G01G 23/01 G01L 25/00

Claims (1)

(57) [Claims] 1. A sting mounting frame in which one end of a wind tunnel balance is connected via a sting, a carry body in which the other end of the wind tunnel balance is inserted, and X,
Forces in the Y and Z axis directions and moments Mx,
A load mechanism for applying My and Mz, a displacement detecting means for detecting displacement of the carry body, and moving the Sting mounting frame in the X, Y, and Z directions relative to the carry body and rotating around the axes. When the carry body is driven by the load mechanism, the amount of displacement of the Sting mounting frame with respect to the carry body in the X, Y, and Z-axis directions and the respective axes are determined based on the output of the displacement detection means. Control means for controlling the restoring mechanism so that the peripheral displacement angle falls within a predetermined range.