JPH02272308A - Non-contact type shape measuring instrument - Google Patents

Abstract

PURPOSE:To improve the measurement accuracy by receiving a light beam in the direction being orthogonal to the surface containing a projection axis of a measuring instrument and a normal of the surface to be measured, based on an inclination of the surface to be measured, calculated, based on already calculated data. CONSTITUTION:On the downward part of an arch 20, a transfer device 22 for an object to be measured is provided so that it can slide in the X, Y and Z directions. On the arch 20, a sensor turning driving motor 32 is provided so as to turn a optical sensor 30. The optical sensor 30 measures a distance to the object to be measured by a theory of a trigonometrical survey by projecting a laser light onto a turning axis, and photodetecting a reflected light from the object to be measured from its side face. Subsequently, based on already calculated data, a normal of the surface to be measured is derived, and the optical sensor 30 is rotated so as to receive a light beam from the direction vertical to the surface containing the projection axis and the normal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for measuring the shape of a ΔIII constant object without contacting the surface to be measured.

[Conventional technology]

Conventionally, contact-type shape measuring instruments have been used to measure the shape of fixed objects such as press-molded products and resin molds, by avoiding direct contact of the measurement needle with the surface to be measured and reading the position. However, this device had the disadvantage that the aPj needle was worn out. Therefore, in recent years, non-contact shape determination devices have been developed, and one of them has been proposed that uses the triangular 1Pl-Jlil method.

This device will be explained based on FIG. In the figure, 8
0 is an optical sensor equipped with a light emitting and light receiving means, and the light receiving means has a light receiving area extending in the W-axis direction in the figure. This optical sensor 80 irradiates the irradiation light A onto the Yen1 constant plane S, receives the reflected light B by the light receiving means, and receives the reflected light B from the light receiving position (the light receiving position in the W axis direction).
The distance between P1 and S is calculated.

[Problem to be solved by the invention]

However, as shown in the figure, if the surface to be measured S is curved inward with a large curvature, not only the normal reflected light B incident from the All fixed point P at the shortest distance but also the two The next reflected light B' is incident on the light receiving means, which may prevent accurate determination of ΔP1. Also, as shown in FIG. If the inclination angle of the IFj constant plane S is large, the object to be measured itself becomes an obstacle and the reflected light is weakened or is completely blocked and does not reach the light receiving means, making it impossible to determine aFI.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a non-contact type shape measuring device that can solve problems caused by the shape of a Δ-j constant surface and measure the shape with high accuracy.

[Means to solve the problem]

The present invention includes an optical sensor having a light emitting means and a light receiving means, the light emitting means irradiates light onto a plane 71111, and the reflected light is received from a position where the light receiving means receives the light.
In a non-contact type/IP+ constant device that sequentially records distance data between a flu fixed point on a III constant plane and an optical sensor, the optical sensor can be rotated around the optical axis of the light irradiated by the light emitting means. a driving means 10 configured to rotate the optical sensor, as shown in FIG.
ilN with respect to the above optical axis from the already determined distance data.
Calculating means 12 calculates the inclination of the surface to be measured at a fixed point, and based on the calculation result, the light emitting means and the light receiving means are arranged approximately relative to the plane including the optical axis and the normal vector of the constant surface A-1. The control means 14 controls the turning drive of the optical sensors so that they are arranged in orthogonal directions.

Furthermore, it is more effective if a comparison means 16 is provided to compare the inclination of the A11l fixed plane at the AFJ fixed point with a preset inclination, and the optical sensor is rotated only when the former exceeds the latter. .

[For production]

According to the above configuration, based on the inclination of the surface to be measured calculated based on the already calculated data, the light emitting means and the light receiving means of the optical sensor are aligned to a plane including the optical axis of the irradiated light and the normal vector of the surface to be measured. Since the optical sensors are rotated so as to be aligned in orthogonal directions, the light emitted from the light emitting means and reflected by the ΔPI constant surface is reliably incident on the light receiving means with a short width.

Furthermore, according to the method that compares the inclination of the surface to be measured with a preset inclination, the optical sensor is driven to rotate only when the inclination of the APj plane with respect to the optical axis exceeds a predetermined standard. Ru.

〔Example〕

FIG. 2 shows the overall configuration of a shape 71r11 fixing device in one embodiment of the present invention.

In the figure, 20 is an arch, and a measured object transfer device 22 is installed below this arch 20. This measured object transfer device 22 includes an X slide member 241 and a Y slide member 24 that are slidable in each axis direction of x, y, and z.
2, and a Z-axis slide member 243, each slide member 241-243 has an X-axis drive motor 261, a Y-axis drive motor 262, a Z-axis drive motor 263 (see FIG. 4 below), and a drive shaft of each motor. It is designed to be slidably driven by a ball screw 27 connected to.

A table 28 on which all fixed objects are placed is fixed to the upper part of the Z-sliding member 243.
An optical sensor 30 is provided above.

The sensor 30 is connected to a sensor rotation drive motor 32 fixed to the upper part of the arch 20 and a reduction gear (not shown) and a rotation shaft 3.
1, and around this pivot axis 31 (around the Z axis)
It is possible to rotate.

As shown in FIG. 3, a semiconductor laser (light emitting means) 36 and a position reading sensor (light receiving means) 37 are provided in the housing 34 of the optical sensor 30, and an inclined wall 341 formed at the lower part of the housing 34 Condensing lens 3
8 is fixed.

The semiconductor laser 36 is disposed at a position where the optical axis of the irradiated light A coincides with the rotation axis 31, and the position reading sensor 37 spreads in the W-axis direction at a predetermined angle with respect to the Z-axis. It has a light-receivable area. Sensor 30 ahead
The semiconductor laser 36 irradiates the surface S to be measured with the irradiation light A, and the reflected light B is sent to the condenser lens 38.
The light is received by the position reading sensor 37 via the light receiving sensor 37, and the light receiving position (specifically, the light receiving position in the W-axis direction) is read.

FIG. 4 shows an arithmetic and control device 40 provided in this shape IP1 determining device. This arithmetic and control device 40 includes the position reading sensor 37 and ΔP1 length devices 421 to 423 that determine the transfer distance of the object to be measured in each axis direction.
The arithmetic and control unit 40 outputs a display device 44, a data recording device 46, the sensor rotation drive motor 32, and drive motors 261 for each of the x, y, and z axes.
A control signal is outputted to . ing. Note that the display device 44 is for displaying the AI determined shape data, and the data recording device 46 is for recording the calculated data on a magnetic disk.

Next, the shape AFI constant operation performed by this device will be explained.

First, with the first fixed object placed on the table 28, the Z-axis slide member 243 is driven up and down to a position where all the fixed objects 11P1 can be set. Normally,
Although the height of the table 28 is fixed at this stage, if the surface S to be measured of the object to be measured has large undulations, the Z-sliding member 28 may be moved as appropriate under the control of the arithmetic and control unit 40 during measurement. The object to be measured is always kept at a height position where aF1 can be determined.

At this position, as shown in FIG. 3, irradiation light A is irradiated onto the surface to be measured S from the semiconductor laser 36 within the optical sensor 30. After this irradiation light A is reflected by the above-mentioned Δ1 constant plane S, it passes through the condensing lens 38 and is received by the position reading sensor 37, and its light receiving position (light receiving position in the W-axis direction)
A signal related to this is manually input to the arithmetic and control unit 40. The arithmetic and control unit 40 controls the semiconductor laser 3 based on this information signal.
The distance from 6 to 71-1 fixed point P is calculated and the data is output to display device 44 and data recording device 46.

On the other hand, by appropriately operating the X-axis drive motor 261 and the Y-axis drive motor 262 according to the control signal of the arithmetic and control unit 40, the X-axis slide member 241 and the Y-axis slide member 242 are driven in the respective axial directions, and the optical sensor 30
The AFI constant is transferred relative to the AFI object. As a result, main scanning and sub-scanning of the optical sensor 30 with respect to the constant object Al11 are performed, and by performing such scanning and the aPI constant operation in parallel, the constant plane S
The height position of each point above is read in sequence, and as a result, the overall shape is determined.

Further, in this device, the direction of the optical sensor 30 is adjusted six times at each API fixed point by outputting a control signal from the arithmetic and control unit 40 to the sensor rotation drive motor 32. Next, the specific control contents will be explained.

In FIG. 5, 51 is an undefined area (plain area in the figure) where API has not yet been determined on the surface to be measured, and 52 is an already measured ΔI11 constant area (shaded area in the figure). The arithmetic and control unit 40 selects an area (mesh area in the figure) 5 near the current 1llll fixed point P in the number 1 constant area 52.
The distance data calculated in step 3 is extracted, and the inclination of the surface to be measured S at the 4p1 fixed point P is calculated based on these data. In this device, data on nine measured points near the measuring point P are extracted, and based on these data, Δp of the surface to be measured S as shown in FIG. 6 is determined by the least squares method.
The inclination of the contact surface Q at one fixed point P is calculated.

In this embodiment, the normal vector at the measuring point P of the contact surface Q as shown in FIG. 7 is calculated as the above-mentioned inclination.

The arithmetic and control unit 40 calculates the angle φ between the normal vector n and the optical axis of the irradiation light A, and compares this angle φ with a preset angle (100 in this embodiment).

If the angle φ is less than the set angle, the optical sensor 30 is not rotated, but if the angle φ exceeds the set angle, the intersection line (i.e., contour line) L between the tangent plane Q and the XY plane is determined, and the corresponding Find the angle θ between the intersection line and the X axis,
The optical sensor 30 is rotated so that the semiconductor laser 36 and the position reading sensor 37 are aligned in the same direction as this intersection line.

According to such an apparatus, when the surface to be measured S is tilted by a certain amount or more with respect to the optical axis of the irradiation light A, the direction perpendicular to the plane containing the normal vector 几 and the optical axis of the irradiation light A; That is, since the optical sensor 30 is rotated so that the semiconductor laser 36 and the position reading sensor 37 are lined up in the direction of the contour line of the APj constant plane S, the APJ constant plane S is rotated as shown in FIGS. The undulations of S do not affect the reflected light B, and a good 71p1 constant can always be performed at each al fixed point.

Furthermore, as described above, the optical sensor 30 is used only when the angle φ between the normal vector 几 and the optical axis is greater than a certain value, that is, when the shape of the Δ−1 constant S affects the nj constant accuracy.
By rotating the optical sensor 30, the time required for rotating the optical sensor 30 can be minimized, and the constant efficiency of the aFJ can be improved.

Note that the present invention is not limited to this embodiment, and can also take the following embodiments as an example.

(1) In the present invention, it is sufficient that the optical axis of the irradiated light and the rotation axis of the optical sensor match, and the specific directions of both axes do not matter.

For example, when the surface to be measured is irradiated with light in the X-axis direction, the pivot axis of the optical sensor may be set in the same direction.

(2) In the present invention, the direction of the optical sensor does not need to strictly coincide with the direction perpendicular to the plane containing the optical axis and the normal vector, and there may be some variation between the two as long as it does not affect measurement accuracy. There may be differences. Further, there is no need to actually calculate the normal vector, and the object of the present invention can be achieved by controlling the optical sensor so that it faces in the above direction.

(3) The present invention allows for different types of light emitting means and light receiving means.
First, it can be applied to an API constant device in which the 4P1 constant accuracy changes when the direction of the sensor changes with respect to the shape of the P1 constant object.

〔Effect of the invention〕

As described above, the present invention calculates the inclination of the ΔP1 constant plane with respect to the optical axis of the irradiated light from data already detected by the optical sensor, and the light emitting means and light receiving means of the optical sensor calculate the inclination of the ΔP1 constant plane with respect to the optical axis of the irradiated light. Since the optical sensors are rotated about the optical axis tit so that they are arranged in a direction substantially perpendicular to the plane containing the normal vector of the surface, the -1 constant This has the effect that the receiving position of reflected light can always be read with high precision regardless of the shape of the object.

Furthermore, if the angle formed by the normal vector of the fixed object and the optical axis is compared with a preset angle, and the optical sensor is rotated only when the former exceeds the latter, the light By minimizing the time required to rotate the sensor, the IIPj constant efficiency can be improved.

[Brief explanation of drawings]

FIG. 1 is a functional configuration diagram of the main parts of a non-contact shape measurement device of the present invention, FIG. 2 is an overall configuration diagram of a non-contact shape measurement device according to an embodiment of the invention, and FIG. 3 is the same device. Figure 4 is a diagram of the internal structure of the optical sensor installed in the device, Figure 4 is a node configuration diagram of the arithmetic and control unit installed in the device, and Figure 5 is a diagram of the internal structure of the optical sensor installed in the device. An explanatory diagram showing the non-4P1 constant area and the existing Mill constant area on the I constant plane, FIG. 6 is a perspective view showing the tangent plane at the measurement point of the same wave measurement, and FIG. 7 is the same tangent plane and the same tangent plane. FIGS. 8 and 9 are explanatory diagrams showing the relationship between the shape of the surface to be measured and the reflected light incident on the optical sensor. 10... Driving means, 12... Calculating means, 14...
Control means, 16... Comparison means, 30... Optical sensor,
32...Sensor swing drive motor (drive means), 36.
... Semiconductor laser (light emitting means), 37... Position reading sensor (light receiving means), 40... Arithmetic control device (arithmetic means, control means, and comparison means), A... Irradiation light, B
...Reflected light, P...Measurement point, S...Measurement surface, U
...Normal vector, φ...Angle between the normal vector and the optical axis. 1 person for patents Minolta Camera Co., Ltd. 11th representative Patent attorney Etsushi Teai
Patent Attorney Cho 11 Masame Patent Attorney
Takao Ito

Claims (1)

[Claims] 1. A light sensor having a light emitting means and a light receiving means;
In a non-contact type shape measuring device, distance data between a measurement point on the surface to be measured and an optical sensor is sequentially obtained from a position where the surface to be measured is irradiated with light by the light emitting means and the light receiving means receives the reflected light. , the optical sensor is constructed to be able to rotate around the optical axis of the light irradiated by the light emitting means, and a drive means for driving the optical sensor to rotate, and a drive means for rotating the optical sensor, and a drive means for rotating the optical sensor, and a drive means for rotating the optical sensor, and a drive means for rotating the optical sensor, and a drive means for rotating the optical sensor, and a drive means for rotating the optical sensor, and a drive means for rotating the optical sensor; calculation means for calculating the inclination of the surface to be measured, and based on the calculation result, the light emitting means and the light receiving means are arranged in a direction substantially perpendicular to a plane including the optical axis and the normal vector of the surface to be measured. 1. A non-contact shape measuring device, comprising: control means for controlling rotational drive of an optical sensor. 2. The non-contact shape measuring device according to claim 1, further comprising comparison means for comparing the inclination of the surface to be measured at the measurement point with a preset inclination, and rotating the optical sensor only when the former exceeds the latter. 1. A non-contact shape measuring device, characterized in that the control means is configured to