JPS60211302A - Inclination measuring instrument - Google Patents

Abstract

PURPOSE:To measure the tilt angle of a body which has a columnar smooth outer peripheral surface automatically without contacting by projecting light on the outer peripheral surface of the body to be measured, and photodetecting its reflected light at plural positions and calculating the tilt angle of the reflected light from a reference surface from the obtained position signals. CONSTITUTION:The inclination measuring device consists of a projection part 4 which has a light source 1 such as a laser diode, a reflecting mirror part 5 which photodetects layer light reflected by the outer peripheral surface of the body 2 to be measured at three positions and reflects it upward, a position detecting part (image sensor) 6 which photodetects plural laser light beams reflected by the reflecting mirror part 5 individually and outpus electric signals indicating the photodetection positions, and an arithmetic processing part. The optical axis 9 of the projection part 4 and the inclination measurement reference line 10 of the body 2 to be measured are set crossing each other almost at right angles. Then an output electric signal of the image sensor 6 which indicates a photodetection position is inputted to the arithmetic processing part, the tilt angle of reflected light on the outer peripheral surface of the body 2 from the reference line 10 is calculated on the basis of the electric signal, and the tilt angle is obtained on the basis of the calculated tilt angle.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a tilt measuring device for non-contactly measuring the tilt of a cylindrical object.

[Technical background of the invention and its problems]

Generally, when measuring the inclination of a cylindrical object, conventionally, a contact displacement meter is used to measure the position of the columnar object at multiple locations, and the amount of inclination is calculated based on the obtained position data. was. for example.

Align the axis of the probe of the differential transformer in a specific direction.

The position was measured at two points at different heights, and the angle of inclination was calculated based on the distance in the height direction between the two points and the difference between the position data from the differential transformer. Therefore, usually one position measurement is performed from two directions that are perpendicular to each other.

He fell down and held θX and θy three-dimensionally.

However, the conventional inclination measurement described above cannot be applied when the surface of the cylindrical object is easily damaged by contact measurement or when it is impossible to apply external force. Furthermore, simultaneous measurement of three-dimensional inclination angles θX and θy is not possible.

Moreover, since the measurement work is relatively complicated, it is time-consuming and difficult to automate.

[Purpose of the invention]

The present invention has been made in consideration of the above circumstances.

An object of the present invention is to provide an inclination measurement device that can automatically and non-contactly measure the inclination angle of an object having a cylindrical shape and a smooth outer surface.

[Summary of the invention]

Light is projected onto the outer surface of the cylindrical part of the object to be measured, at least a part of which is formed into a cylindrical shape, and this cylindrical part is a smooth surface, and the reflected light is received at a plurality of positions to determine the position. The inclination angle of the reflected light from the reference plane is calculated based on the converted position detection signal, and the inclination angle is calculated based on the calculated inclination angle.

[Embodiments of the invention]

The following is part 1 of the present invention! Examples will be described in detail with reference to the drawings.

FIG. 1 shows a tilt measuring device according to one embodiment. This inclination measuring device uses a light source such as a laser diode (1).
1) and a hypothetical object (described later) on the opposite side of the object to be measured (2), which is formed into a cylinder and whose outer peripheral surface is a mirror surface that specularly reflects the laser light emitted from this light source (1). A light projection unit (
4), and a reflecting mirror part (5) that receives the laser light projected from the light projecting part (4) and reflected on the outer peripheral surface of the object to be measured (2) at three locations and reflects it upward. ), and a position detection unit (
6) and a calculation processing unit (7) (see Fig. 2) that calculates the inclination angle of the object to be measured (2) based on the electrical signal output from the position detection unit (6). For example, a CRT (Ca
Display section (8) such as Thode Ray Tube)
(See Figure 2). Therefore, the original axis (9) of the light projector (4) and the inclination measurement reference line (11) of the object to be measured (2) are set to be almost orthogonal to each other. 5) includes a semi-transparent mirror (11) and a first.
The second surface mirror (Ia, consisting of a mirror, semi-transparent mirror Ql) is installed on the optical axis (9).

Laser light reflected from the object to be measured (2) along this optical axis (9) is reflected upward along an optical path α orthogonal to the optical axis (9). Also, 1st. 20th
The surface mirrors (12, Ql are perpendicular to the measurement reference line a1 and are provided on a virtual plane including the optical axis (9), separated by an angle α on both the left and right sides of the optical axis (9), Object to be measured (2
) to reflect the laser beam upward.

At this time, the first. The extension of the line of intersection between the second surface 5QL (1:I and the virtual plane) is set to intersect the optical axis (9) at an angle of 45 degrees. 9)
The optical path o! is separated by an angle α! 9. The laser beam that has followed cua has an optical path a “0.αe” orthogonal to the virtual plane.
It is set to reflect upward along the Thus, the first position detection unit (6) is a first image sensor that receives the laser beam along the optical path I.

It consists of a second image sensor screen that receives the laser beam along the optical path aη, and a third image sensor Qυ that receives the laser beam along the optical path Oe. These first. Second. The third image sensor (Il, Kan, Ql) is one such as CCD (Charpe Coupled DevI).
ce). Then, the line of intersection between the light-receiving surface of the first image sensor wing and the plane including the optical axis I and the measurement reference line (II) is parallel to the optical axis (9). The element rows are arranged in a line direction.

Furthermore, the line of intersection between the light-receiving surface of the second image sensor and the plane including the optical axis aη and the measurement reference line On is parallel to the optical axis α), and the direction of this line of intersection is Km are set to be arranged. In addition, a third image sensor C
The line of intersection between the light-receiving surface of 21) and the plane containing the optical axis α and the measurement reference line H is parallel to the optical axis 0[9], and the element array is arranged in the direction of the intersection with the optical axis 0[9]. is set to

Furthermore, the second. Third image sensor (a), (2υ optical path (17), laser beam receiving position 12 via QS
3. (The distance between 231 is set to 1x. Also, as shown in Figure 3, the light receiving position (22, (
The midpoint (c) of the line segment a connecting between 23j and the optical path (14) of the first image sensor a→ is set to be in the X-axis direction. The distance from the receiving position (c) of the laser beam that has passed through is set to Jy.

Here, in FIG. 3 and FIG. 2, the 1st and 2nd. Although the arrangement of the third image sensor (11, G!I, CI!1) is slightly different, this is for convenience as will be described later, and they are optically completely equivalent. Furthermore, 1st degree, 2nd degree. The output side of the third image sensor (11, (21, (2m)) is.

Connected to the input side of the signal processing circuit, @, and @, respectively. These signal processing circuits -, @, and @ consist of a binarization circuit and a counter circuit. The third image sensor (Il, cA, *η) is adapted to output a signal indicating the light receiving position 1x, , nx, , ny. The output side of (21) is an arithmetic and control device (7) such as a microcombi, etc.
)It is connected to the. And this arithmetic and control device (to)
and the signal processing circuit @, (to), @ is the arithmetic processing unit (
constitutes power.

Next, the operation of the inclination measuring device having the above configuration will be described.

First, the measurement angle of the inclination measuring device of this embodiment will be explained. Then, the laser beam O0 projected from the light projecting section (4)
is focused on the object to be measured (2) as shown in FIG.
, as shown in Figure 5.

This minute? l1fdSt acts as a convex mirror, and the laser beam 0υ follows the arrows p, , p, , p, , p, ,
As shown by p, the light is reflected radially and diffusely around the virtual focus P of the convex mirror. On the other hand, the part to be measured (2
), as shown in FIG. 6, this microsurface ds acts as a plane mirror, and the laser beam Gυ is.

The light is reflected so as to be focused on a focusing point P' located in a bilaterally symmetrical position with respect to the virtual focal point P. At this time, if the axis (2a) of the object to be measured (2) is inclined by an angle O with respect to the measurement reference line -, the focal point P' also changes by an angle 20 with respect to the reference point. Therefore, it is possible to calculate the angle of inclination conversely from the amount of displacement of the focal point P'.

That is, as shown in FIG. 7, the three-dimensional coordinate space x-y
-z, when the measurement reference line OI is on two axes, if the axis (2a) of the object to be measured (2) is inclined by the inclination angle θ, then the inclination angle in the x -z space is θX
And the inclination angle in the y-z space is θy. Therefore, the above-mentioned inclination angle θX is the function of the light receiving position in FIG.
It can be determined by the height difference Δhx. Suhiko Wachi,
As shown in FIG. 8, since the distance 1x between the second and third image sensors (A) and an is constant, the height difference Δ
If hx is known, the inclination angle θX is.

It can be claimed using the following formula (■).

tan Bθx=Δhx/A! −・−・・−(i
) Similarly, the above-mentioned inclination angle θy can be determined based on the light receiving positions (2), (c), and (c) in FIG. 3).

In other words, since the distance 1y between the midpoint (C) and the light receiving position (C) is constant, the distance 1y between the midpoint (C) of line segment 04 and the light receiving position (C) is constant.
If you know the height difference Δhy・ from C), the inclination angle θy is 1
It can be claimed using the following formula (■).

tan2θy = Δhy / Ly...=■Here, the height at the midpoint (C) is located between the heights at the light receiving positions (2) and (C), so the height difference is Δh.

can be determined by the linear equation (■).

Therefore, the arithmetic and control device stores arithmetic programs corresponding to the second, ■, and ■, and the inclination angles θ
is automatically calculated. Thus, when the laser beam 011 is oscillated from the light source (1) toward the object to be measured (2) which is inclined by the inclination angle ax, Oy with respect to the measurement reference line α0, this laser beam 6υ is The light is focused by the lens (3) so as to converge to a virtual focal point P. Next, the focused laser beam Gυ is applied to the object to be measured (2)
It is reflected at the outer circumferential surface of. The reflected laser beam passes through the semi-transparent mirror (11) and the first . are reflected upward by the second surface mirror nun, respectively. Second. Third image sensor 01. (Electrical signal SA of the voltage value received by 21, c!υ and corresponding to the light receiving position (c), 122. (to)
.

8B, converted to SC. These electrical signals SA, S
B and 8C are signal processing circuits (27), respectively.
(, !I is applied.

By the way, Fig. 10 shows the electric signals SA, SB, SC.
FIG. 2 is a schematic diagram of the waveform in which the voltage value increases rapidly only at the light-receiving spot portion. Therefore, 1gI processing circuit (goods),
aS.

In (a), this voltage increase portion is clearly distinguished by binarization processing, and a counter function is used to calculate which bit from the beginning of the total number N of bits this voltage increase portion corresponds to. However, these signal processing circuits, c!
From at, (c), a signal SD indicating the light receiving position oe, +2 pit positions ny, nxl, nx,
SE and SF are output to the arithmetic and control unit (7). Next, in this calculation leg restraint device (to), the bit position ICY
, nxl, nX, by the pitch interval e of 1 bit to calculate the height hY+hxl+''t.

Next, from the heights hX, , hX, the height difference Δhx can be calculated using the following equation (2).

Δhx == hxl h,, '・”... ■However, in the arithmetic control section (towards), the calibration value Δhxo
, ΔhyO are stored. These calibration values Δhxo,
△hyO is determined by first placing a calibration cylinder having the same shape as the object to be measured (2) with its axis aligned with the measurement reference line (11), and then using the signals SA, 8B, and 8C obtained at this time. , was obtained using the same algorithm as above.

Next, the calibrated height differences Δhxm and Δhym are calculated using the υ linear equation ■■ based on the requested height differences ΔhX and Δh and the calibration values Δhxo and ΔhXo.

The calibrated height difference Δh claimed by this formula ■, ■
By substituting xm and Δhym into the ΔhX and Δh parts of formulas ■ and ■, respectively, the inclination angles θX and θy are calculated.
will be displayed at

In this way, the inclination measuring device of this embodiment can be used to measure the object to be measured (
2) The angle of inclination can be measured in a non-contact manner without causing damage without applying external force. Moreover,
Three-dimensional inclination angles θX and θy can be measured simultaneously. Furthermore, since the measurement is automated, the measurement time is extremely short, less than a few seconds, and the measurement efficiency is dramatically improved.

In the above embodiments, a cylindrical object is exemplified as the object to be measured, but as shown in FIG. There may be. Furthermore, as a light source.

The light source is not limited to a laser light source, and a general tungsten lamp or halogen lamp can also be used through a pinhole. Further, in the above embodiment, a configuration may be adopted in which only one of the inclination angles θX and θy is measured without simultaneously measuring them. For example, the inclination angle θX
If you only want to measure.

Front mirror (IL (at position 11, image sensor wire, C!
1) may be provided. Not only the inclination angle θX, θ1
Measurement of other inclination angles is also possible by changing the arrangement position of the image sensor. Furthermore, as image sensors, it is not limited to COD (ITV (industrial television) cameras, physical exposure sensors, MO8 (Met), etc.
Any type of image sensor may be used.

〔Effect of the invention〕

Since the inclination measuring device of the present invention is of a non-contact type, it is possible to measure the inclination angle without applying external force to the object to be measured and without damaging the surface. Furthermore, the angle of inclination can be determined three-dimensionally and automatically. As a result, measurement accuracy and measurement efficiency are improved.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a tilt measuring device according to one embodiment of the present invention, FIG. 2 is an electric circuit diagram, FIG. 3 is an explanatory diagram of the arrangement of the image sensor in FIG. 1, and FIG. or 9th
10 is a diagram showing the waveform of an output signal from an image sensor, and FIG. 11 is a diagram showing a modification of the object to be measured. (2): Object to be measured, (41: Light projecting section. (6): Position detection section, (7): Arithmetic processing section. Q1 = Measurement reference line. Agent: Patent attorney Noriyuki Chika (and 1 other person) Figure 1 Figure 2 0 Figure 3 Figure 10 -N--- Figure 4 Figure 7 Figure 8 Figure 9

Claims (1)

[Claims] In an inclination measuring device for measuring an inclination angle from a reference direction of an object to be measured, at least a part of which is formed in a cylindrical shape and the outer circumferential surface of this cylindrical portion is a smooth surface, I: irradiates light onto the outer circumferential surface. a light projecting section for projecting light; a position detecting section that receives the reflected light of the light projected from the light projecting section at a plurality of positions separately and converts it into an electrical signal indicating the light receiving position;
An inclination measuring device comprising: an arithmetic processing unit that calculates an inclination angle of reflected light at this position with respect to a plane orthogonal to the reference direction, and calculates the inclination angle based on the calculated inclination angle.