JPS59190607A - Contactless measuring device for measuring shape of body - Google Patents

Abstract

PURPOSE:To shorten the measuring time, by providing an operation control mechanism, which drives and controls the driving amount and the attaching angle of a three-dimensional driving mechanism of a displacement gage, and crossing the axis of the rotary center of an angle changing mechanism and the extended line of the optical axis of emitted light. CONSTITUTION:A displacement gage 40 is attached to a cross head 22 over a body to be measured 1, which is placed on a base table 20. The cross head 22 is slidden in an arm 23 of a three-dimensional driving mechanism and driven right and left by a motor 26. Therefore, the displacement gage 40 can be moved in the direction of the x axis. Driving in the direction of the (y) axis is performed by a longitudinal feed screw 28 and a gear box 30. The entire driving mechanism on a base table 32 is driven in the direction of the axis by a motor 31. Meanwhile, an angle changing mechanism 21 rotates an arm 34 around a rotating central shaft 33, which is in parallel with the (x) axis. An angle changing mechanism 21', which is attached to the lower end of the arm 34 turns the displacement gage 40 around a rotating central shaft 33', which is in parallel with the (z) axis.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a non-contact measurement device for measuring the shape of an object, and in particular, an optical method using laser light or the like to measure the shape of an object, which is suitable for shortening calculation time during shape measurement. The present invention relates to a non-contact measurement device that uses a target displacement meter to perform non-contact measurement.

[Background of the invention]

BACKGROUND ART In recent years, with the development of ogive electronics, devices have been developed that measure the shape of objects in a non-contact manner using optical means such as laser light. Conventionally, the mainstream of such devices has been the scanning measuring device, so below we will introduce an example of it in the first section.
This will be explained using figures.

Figure 1 is a side view of a conventional shape measuring device.
A drive table 2 is disposed outside the drive table 2, and the drive table 2 is driven three-dimensionally (X, y, and z-axis directions shown in the figure) by drive mechanisms 3 and 3'. On the drive table 2 is a light source 4 such as a laser beam. Semi-transparent mirror 5. Lens 6.7.
An optical system consisting of a vibrating pinhole 8 and a light receiver 9 is arranged. Further, an oscillator 10 for vibrating the vibration pinhole 8, an amplifier 11 for amplifying the output of the light receiver 9, and an operation using the output of the amplifier 11 are used to calculate the drive mechanism 3, 3'.
An arithmetic and control device consisting of an arithmetic and control circuit 12 is provided.

Now, assuming that the distance y between the object to be measured 1 and the lens 6 is equal to the focal length A of the lens 6, the reflected light connects a hot point at the center of the amplitude of the vibration pinhole 8, as shown in FIG. Therefore, the output of the light receiver 9 has a frequency 2f, which is twice the excitation frequency f, as shown in FIG. 2, which is an explanatory diagram of the relationship between displacement and output in the case of FIG. 1. Also, the distance y is A
If they do not match, the output frequency becomes f, and the phases become in-phase or anti-phase depending on the distance y.

Therefore, if the driving mechanisms 3 and 3' are controlled so that the distance y becomes equal to A based on the detection results of these frequencies and phases, the measured object 1 will be
The shape can be copied and measured.

However, this type of shape measuring device has the following problems.

(1) Measurement time is long. This is the X-y of the object to be measured 1.
This is because when measuring the cross-sectional shape, it is necessary to always drive in the y-axis direction in conjunction with the drive in the x-axis direction.

(2) If the inclination angle of the surface of the object to be measured 1 is large, measurement cannot be performed. This fd is because as the angle α between the normal to the surface of the object 1 to be measured and the irradiation optical axis at the point to be measured (see Fig. 1) increases, the amount of reflected light directed toward the light receiver 9 decreases. .

[Purpose of the invention]

The present invention has been made in view of the above, and its purpose is to be able to shorten the measurement time and also to be able to perform shape measurement even if the surface of the object to be measured has a steep slope. An object of the present invention is to provide a non-contact measurement device for measuring the shape of an object.

[Summary of the invention]

The first feature of the present invention is that the displacement meter that is three-dimensionally driven against the surface of the object to be measured is mounted using one angle changing mechanism that changes the angle, and the distance measured by the displacement calculation 4. ,
an arithmetic control mechanism that performs necessary calculations by inputting the drive amount of the three-dimensional drive mechanism and the mounting angle of the displacement meter, and drives and controls the three-dimensional drive mechanism and the angle change mechanism described in "2"; The central axis of rotation of the angle changing mechanism and the extension of the optical axis of the irradiated light from the displacement meter are configured to intersect at a point. The second feature is that there is a plurality of angle change mechanisms, and the rotation center axis of the angle change mechanism closest to the displacement meter -1- among them intersects the extension line of the optical axis of the heat radiation from the displacement side. The rotation center axis of the angle changing mechanism closest to the three-dimensional drive mechanism is configured to be parallel to the drive axis of any one of the three-dimensional drive mechanisms.

[Embodiments of the invention]

The present invention will be described below as shown in FIGS. 3, 4, 7, 12, and 1.
This will be described in detail using the embodiment shown in FIG. 3 and FIGS. 5, 6, 8 to 11, 14, and 15.

FIG. 3 is an overall configuration diagram showing an embodiment of the non-contact measuring device of the present invention. In Figure 3, 2o is the base, 1i-1
: An object to be measured placed above the base 2o. Above the object to be measured 1, there are two displacement meters 40 and two angulation mechanisms 21.
It is located attached to the crosshead 22 via 21'. 22 crossheads, a foot that slides onto the arm 23 of the three-dimensional drive mechanism, a guide section 24, and a horizontal feed screw 2
5 and the motor 26, the displacement meter 40 is also movable in the illustrated X-axis direction. The drive in the y-axis direction of the three-dimensional drive mechanism is by the motor 27.
This is done by a vertical feed screw 28 which is coupled to the arm 29 and a gear box 3o which is slidably fitted to the arm 29, and further,
The motor 31 is mounted on a base 32 and drives the entire drive mechanism in the axial direction.

On the other hand, the arm 34 is rotated around the rotation center axis 33 which is parallel to the angle change mechanism 21 (/i, y-axis) attached to the crosshead 22.The angle change mechanism 21' is attached to the lower end of this arm 34. The displacement meter 40 is rotated around a rotation center axis 33' parallel to the y-axis.

Therefore, the displacement meter 40 is movable in the three axial directions of the X2y and y axes, and the angle changing mechanisms 21', 21'
Accordingly, the circumference D of the y-axis and the rotation axis parallel to the y-axis (i=rotation is possible.

FIG. 4 is a diagram showing a schematic structure of the displacement meter 40 shown in FIG. 3 and how it is attached to the arm 34. A light beam emitted from the laser beam 41 passes through the irradiation lens 42 and irradiates the second measurement point P on the surface of the object to be measured 1, and the diffusely reflected light from the point P is directed toward the irradiation optical axis 45. The light is focused by a condensing lens 43 arranged on an axis having an angle β, and detected by a light receiver 44. The distance is measured when the distance between the measured object 1 and the displacement meter 40 changes (in FIG. 4, the distance t L between the measured object 1 and the rotation center axis 33').
This is done using the principle that the incident position on the light receiving surface of the light receiver 44 changes. However, there is a limit to the distance that can be measured due to constraints such as the size of the light receiving surface, and furthermore, the lower limit is Lmax and the upper limit is JJ ynin. In addition, in this embodiment, the displacement meter 40 is attached to the portion 46 such that the rotation center axis 33' of the angle change mechanism 21' that rotationally drives the displacement meter 40 with respect to the arm 34 intersects the irradiation optical axis 45. It is connected via.

FIGS. 5 and 6 are diagrams showing measurement limits of the irradiation angle α of the displacement meter 40, respectively. The value of α is defined as 1 dV as the angle between the normal n at the irradiation point on the surface of the object to be measured 1 and the irradiation optical axis 45. As shown in Figures 5 and 6, the value of α is excessive (Figure 5)
Or, if it becomes too small (as shown in Figure 6), the amount of diffusely reflected light in the direction of the receiving optical axis decreases, so it can no longer be detected by the light receiver 44.The upper and lower limits of this illumination angle α are α, respectively. .a engineering, αmin and so on.

FIG. 7 is a block diagram showing one embodiment of the arithmetic and control mechanism of the non-contact measuring device of the present invention. It is input to the displacement control device 51. Further, position information from the magnetic school 52 that measures the drive amount in the X, y, and Z axis directions is input to the arithmetic and control device 51 via the amplifier 53. Furthermore, the angle change mechanism 2
The angle information from the rotary encoder 54 of 1.21' is input to the arithmetic and control unit 51 via the amplifier 55.

The arithmetic and control device 51 calculates the coordinates (X+y+Z) of the irradiation point P on the object to be measured 1 based on this information, and displays the result on the display device 56. Furthermore, regarding distance and illumination angle α, comparison 6I described below
t is calculated, and based on the calculation, the drive motors 26, 27° 31 in the X, y, and Z axis directions and the angle changing mechanism 21.
．． 21. The drive motors 57, 57'' (not shown in FIGS. 3 and 4) are controlled.

Next, the effects of the embodiment will be explained. 1. Displacement meter 4
Explain the effects of using 0].

FIG. 8 is a diagram for explaining the driving method of the displacement meter 40,
As shown in the figure, when the measured object l has a cross-sectional shape of the lower right side with respect to the displacement meter 40, the measurable distance range L min -L+. , Therefore, compared to the conventional example, the measurement time can be shortened due to the reduction in the number of drives in the y-axis direction. In addition, at each measurement point, a comparison calculation is performed between the measured distance value and L max and L min, and control is performed so that the value of L does not completely deviate from the measurable range.

Next, the effect of providing the angle changing mechanism 21, 21' will be explained using FIG. 9. In the case of ■ in the figure, the angle α between the normal j] at the irradiation point P and the irradiation optical axis 45 is within the measurable angle range of αmin to αm8 of the displacement meter 40, but in the case of ■ shown by the broken line, In this case, it falls outside the above range. In this case, as shown in O, the displacement meter 40 is rotated using the angle changing mechanism 21 or 21' (see FIG. 3) so that the value of α falls within the above range. Therefore, the measured value of α and αmin and α at each measurement point.

8K, and if α shows a tendency to deviate from the measurable range, the angle change mechanism 20 or 20
’ is activated. To avoid this fear, to measure the shape of the object 1 to be measured having an arbitrary cross-section, the rotation center axis 33' of the rotational drive mechanism 21' on the displacement meter 40 side intersects the extension line of the irradiation optical axis 45. I will explain the effects of doing so.

For simplicity, the case where the rotation center axis 33' is parallel to the Z-axis will be discussed here. Fig. 10 is an explanatory diagram of this case, and shows the coordinates (XI yl
z) is expressed by the following formula using the coordinates (XI r Yl +Z+)e of the intersection point Q between the extension of the irradiation optical axis 45 and the rotation center axis 33'.

X””Xl+LCO3θ, ...-(1)
Y ”” Y + + Lsinθ<-
−= (2) z = z,
(3) Here, L; length θd of line segment PQ; angle between the irradiation optical axis 45 and the X-axis; on the other hand, FIG. This is an explanatory diagram for the case where the two do not intersect. In this case, the distance between the irradiation optical axis 45 and the rotation center axis 33' is set to 1.
1, and the coordinates of the intersection Q of the plane containing the irradiation optical axis 45 and perpendicular to z11] and the rotation center axis 33' are (XI r yl
+ zI ), then the coordinates of point P (XIy, Z
) is shown by the following formula.

x = x, -1-LCO3θa+hsinθd
”' (4) y= Y + 10Lsinθd7−
h cosθd-(5)2-21
(6) As is clear from comparing equations (1) and (4), and equations (2) and (5), as in the embodiment of the present invention, the rotation center axis 33' and When the extension line of the irradiation optical axis 45 intersects with the extension line of the irradiation optical axis 45, the formula for calculating the coordinates of the irradiation point P becomes simple.

Therefore, the calculation time within the arithmetic and control device 51 is reduced, and the time required for shape measurement can be shortened.

Next, the effect when the rotation center axis 33 of the angle changing mechanism 20 on the three-dimensional drive mechanism side is made parallel to the drive axis of any one of the three-dimensional drive mechanisms will be described. Figure 12 No. 1
3 is a detailed structural diagram of the angle changing mechanism 21.2],' of FIG. 3, FIG. 12 is a front view, and FIG. 13 is a side view. The rotation center axis 33 of the angle change mechanism 21 and the three-dimensional drive mechanism can be accessed from the coordinates (X2) of the intersection with the center line of the arm 58.
+3'2 +z2) is the coordinate (XI +
It can be expressed by the following formula using Yj + zI).

XI-x2-11...(7) Yl = Y2-A2CO3Qa+/:3sinθn
・= (8)zI =Z2+t2sinθn +l
3 COF, θa − (9) where, t, l
t2 + A3; Length Qn of each arm shown; Rotation angle of angle changing mechanism 21 On the other hand, FIGS. 14 and 15 are respectively FIGS.

In the diagram shown in FIG. 13, the following relational expression holds between the coordinates of point Q and point R1 in this case.

xl=x2-IHcO3θ B-A2sinθ s
・-QO)Y ] = Y
2 10s'-1sinill 3-(72cos
θ R-j! ,3sinθ,,)COSθ8...
(II) z1= Z 2 +t2sin On +t3cosθ
n ・(121 Equation (7) and Equation (10), (
Comparing formula 8) and formula 01), formula (9) and formula 32+, we get
As in the embodiment of the present invention shown in FIGS. 12 and 13, three
It can be seen that when the rotation center axis 33 of the angle change mechanism 21 on the dimensional drive mechanism side is arranged so as to be parallel to one axis of the three-dimensional drive mechanism, the formula for calculating the coordinates becomes very simple. Therefore, in this case as well, the calculation time in the arithmetic and control unit 51 is reduced, and the time required for shape measurement can be shortened.

As described above, according to the embodiment of the present invention, since the displacement meter 40 with a wide measurable distance range is used, in addition to reducing the number of drive controls, the calculation time in the arithmetic and control unit 51 can be reduced. This is expected to significantly reduce shape measurement time. In addition, since the displacement meter 40 is coupled to the three-dimensional drive mechanism via the angle change mechanisms 21, 2], ', the mounting angle of the displacement meter 40 can be adjusted even if there is a sudden change in the shape of the object to be measured 1. Shape measurement can be performed without changing the

Further, since the rotation center axis 33' of the angle changing mechanism 21' intersects with the extension of the irradiation optical axis 45 of the displacement meter 40, the calculation time can also be reduced.

It should be noted that the present invention is not limited to the above-described embodiments, and may include the displacement meter 40. Angle change mechanism 21゜21' and 3
The configuration and arrangement of the dimensional drive mechanism may involve variations in line types. For example, in the embodiment of FIG. 3, the angle changing mechanism is 21
Although two cases are shown, 21' and 21', there may be only one angle changing mechanism 21'. Further, the mounting angle of the displacement meter 40 may be an angle other than that shown in FIG. 3, which may be rotated by an arbitrary angle around the irradiation optical axis 45, and substantially the same effect as described above can be expected with these.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to shorten the measurement time, and even if the surface of the object to be measured has a steep slope, the shape i11+1 can be determined.

[Brief explanation of the drawing]

Fig. 1 is a side view of a conventional shape measuring device, Fig. 2 is an explanatory diagram of the relationship between displacement and output when the shape measuring device of Fig. 1 is used, and Fig. 3 is a side view of a conventional shape measuring device. - of contact measuring device
・The overall configuration diagram showing the example. Figure 4 shows the schematic structure of the displacement meter in Figure 3 and the mounting situation on the arm. Figures 5 and 6 show the irradiation angle of the displacement meter, respectively. FIG. 7 is a block diagram showing an embodiment of the arithmetic control mechanism of the non-contact measuring device of the present invention, and FIGS. 8 and 9 are diagrams showing the driving method of the displacement meter, respectively. Diagram for explanation, 1st
FIG. 0, FIG. 11, FIG. 14, and FIG. 15 are explanatory diagrams for explaining the present invention in detail, respectively. FIG. 12 is a front view showing the detailed structure of the angle changing mechanism of FIG. 3, and FIG. 13. is the 12th
FIG. 1. Object to be measured, 20. Base, 21.2'l'...
・Angle change mechanism, 22...Cross head, 23...Arm, 24 ・Guide part, 25-・Screw, 26.27,
31゜57.57'...Motor, 28...Screw, 2
9...Arm, 30...Gear box, 32...Base, 33°33'...Rotation center axis, 34...Arm, 40...Displacement meter, 41...Light source, 42...Irradiation Lens, 43... Condensing lens, 44... Light receiver, 45... Irradiation optical axis, 46... Displacement meter mounting part, 51... Arithmetic control unit, 52... Magnetic scale, 54...・Rotary encoder, 56...Display device. Swamp? Figure stop $3 Figure collection 4 Figure 5 Stone Figure 6 Figure 7 Figure 8 Figure q

Claims (1)

[Scope of Claims] 1. A displacement meter that measures the distance to the object to be measured by receiving the reflected light of the light irradiated onto the surface of the object to be measured, and 3. The displacement meter is driven in all three dimensions. dimensional drive mechanism,
The mounting of the displacement meter includes one angle changing mechanism that changes the angle, the distance measured by the displacement meter, and the three-dimensional one.
The amount of drive of the drive mechanism and the mounting of the displacement meter are determined by an arithmetic control mechanism that inputs an angle and performs necessary calculations, and also controls the drive of the three-dimensional drive mechanism and the angle change mechanism. A non-contact measuring device for measuring the shape of an object, characterized in that a rotation center axis of the changing mechanism and an extension of the optical axis of the irradiated light from the displacement meter are configured to intersect. 2. The object shape according to claim 1, wherein the rotation center axis of the angle changing mechanism and the extension line of the optical axis of the irradiation light are configured to intersect within the range of the thickness of the irradiation light. non-contact measuring device. 3. A displacement meter that measures the distance to the object to be measured by receiving the reflected light of the light irradiated on the surface of the object to be measured, and the displacement meter (i: a three-dimensional drive mechanism that drives three-dimensionally; , the takeoff of the displacement meter is determined by inputting a plurality of angle changing mechanisms that change angles, the measured value of distance by the displacement meter, the driving amount of the three-dimensional drive mechanism, and the mounting angle of each displacement meter. The center of rotation of the angle change mechanism closest to the displacement meter among the angle change mechanisms is The axis is configured such that the extension line of the optical axis of the irradiated light from the displacement meter intersects, and
A non-contact measuring device for measuring the shape of an object, characterized in that the rotation center axis of the angle changing mechanism closest to the dimensional drive mechanism is configured to be parallel to the drive axis of any one of the three-dimensional drive mechanisms. 4. The rotation center axis of the angle change mechanism closest to the displacement meter and the extension line of the optical axis of the irradiation light are configured to intersect within the range of the thickness of the irradiation light. A non-contact measuring device for measuring the shape of an object as described in 2.