JPS6330702A - Shape measuring apparatus - Google Patents

Abstract

PURPOSE:To obtain the title apparatus capable of performing efficient measurement, by absorbing emitted light or reflected light in either one of areas inside and outside of a measuring area by subtractive color mixture on the basis of the relation between the surface hue of an article to be measured and the emitted light of a light source. CONSTITUTION:A contact type probe 4 moves while contacts with the surfaces of an article 2 to be measured and a green sheet 1. The camera 8 having a red filter 9 mounted to the front surface thereof is fixed to the probe 4 and detects the reflected light from a measuring surface of a light source 3 through the filter 9 simultaneously with the movement of the probe 4. Said reflected light is sampled by a sampling circuit 10 and subsequently compared with the value of a threshold value setting circuit 11 by a comparator 12 to be converted to a binary signal. A probe control circuit 6 receives said signal to operate a moving direction (+ or -Y-axis direction) and sends a position in an X-axis direction by one pitch. At this time, the reflected light (green) from the sheet 1 is absorbed by the filter 9. Then, the measurement of the article 2 to be measured is continued by the circuit 6 and the shape of the article 2 to be measured is calculated from drive informations (X, Y-axis planes) and moving quantity informations (Z-axis) is A- and A'-directions.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a shape measuring device for measuring the surface shape of an object having a three-dimensional shape.

BACKGROUND OF THE INVENTION In recent years, due to advances in robot technology and the need for automatic inspection in production processes, it has become an important issue to establish a technology for recognizing objects having three-dimensional shapes. In this three-dimensional object recognition, as a basic step, there is a strong desire for a means to simply and quickly measure the three-dimensional coordinates of each point on the surface of an object having a three-dimensional shape. Especially characteristic lines with slight changes in parts (
High precision is required for three-dimensional coordinate measurement of character lines.

Conventionally, three-dimensional coordinate measurement has been carried out using a method in which coordinates are measured while directly contacting a probe 52 to an object to be measured 51 as shown in FIG. 5, or an optical device 61 is used instead of a poop as shown in FIG. There is a method for non-contact coordinate measurement.

In both of these methods, the probe 51 and optical device 61 that move over the object to be measured 51 are controlled by a control/arithmetic circuit 53 that includes software. That is, the entire measurement range or the measurement range near the character line 54 to be measured particularly precisely can be specified by the program using the two-dimensional (x
, y) This was done by inputting coordinates or specifying the two-dimensional movement amount of the probe.

Problems to be Solved by the Invention However, in the conventional method as described above, each time the shape of the object to be measured 51 changes, the entire measurement range must be specified by inputting coordinates or changing the program. Measurement object 5
In some models, the number of character lines is several dozen or more, and it is necessary to specify the measurement range for each character line.

For this reason, specifying the measurement range by inputting detailed coordinates for each object to be measured becomes very complicated and requires a large amount of work, and specifying the measurement range by simple rectangular approximation also includes areas other than the object to be measured 51. Both were inefficient, as they included a lot of waste.

The present invention aims to solve these conventional problems and provide a shape measuring device that can perform efficient measurements.

Means for Solving the Problems The present invention provides an object to be measured whose surface has a first color, and an area indicating member having a second color for indicating a measurement area of the object to be measured. and a shape measuring means for measuring the three-dimensional shape of the object to be measured, and a filter that absorbs or reflects one of the first and second colors in front, and the shape measuring means that is currently being measured. an optical means for optically inputting reflected light from the light source of the object to be measured or the area indicating member in the means and converting it into an electrical signal; A control means for controlling the drive of the position of the means is provided.

Effect The present invention has the above-described configuration, so that the relationship between the first color of the surface of the object to be measured and the irradiation light of the light source, or the relationship between the first color of the surface of the object to be measured, the irradiation light, and the filter is determined by the measurement. By utilizing the combination of absorbing the irradiated light or the reflected light by subtractive color mixing either within the region or outside the region, the measurement region can be efficiently specified.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1(a) is a block wiring diagram of a shape measuring device according to an embodiment of the present invention, and FIG. 1(b) is a perspective view of the same essential part.

In Fig. 1, 1 is a green sheet on which a gray three-dimensional object 2 is placed, 3 is a light source that provides white light, and 4 is a device that measures the shape of the object 2 while in contact with it. The probe 5 is an area setting circuit in which basic values such as the maximum drive area of the probe 4 are set in advance. Reference numeral 6 denotes a probe control circuit that controls the probe 4 via the probe drive circuit 7 based on information from the area setting circuit 5 and a comparator 12, which will be described later. The amount and direction of movement of the probe 4 are notified to the coordinate calculation circuit 13, which will be described later.

Reference numeral 8 denotes a camera that is moved by the probe driving circuit 7 together with the probe 4 in the vicinity of the probe 4, and a filter 9 that absorbs green image information is provided in the front. 1o is the image information from the camera 8; That is, it is a sampling circuit that photoelectrically converts and samples the reflected light captured by the camera 8. Reference numeral 11 is a threshold setting circuit that sets a threshold level in advance according to the object to be measured 2. Reference numeral 12 is a sampling circuit 10 and a threshold setting circuit. A comparison circuit that compares the output with the circuit 11, and sends a control signal to the broach control circuit 6 to reverse the drive direction of the probe 4 when the comparison value is reversed.13 is the probe 4 (Z-axis direction) and probe control circuit. Information (x
, y, and Z-axis directions) from the shape of the object 2 to be measured (
This is a coordinate calculation circuit that calculates coordinates).

The operation of the above configuration will be explained below.

First, the contact type probe 4 moves while touching the surfaces of the object to be measured 2 and the green sheet 1, and reads the surface shape (coordinates).

In addition, the camera 8 has a red filter 9 attached to the front.
is fixed adjacent to the probe 4, so that when the probe 4 moves on the surface of the object to be measured 2 and the green sheet 1, the reflected light from the measurement surface is simultaneously detected by the camera 9 through the red filter 1. The detected reflected light is sampled by the sampling circuit 10 and then compared with the value of the threshold setting circuit 11 by the comparator 12. In the probe control circuit 6 that controls the movement of the probe 4 (in the X-Y plane), a comparator 12
In response to the binary signal converted by value), the probe drive control is performed to reverse the moving direction (-Y-axis direction) and move the position in the X-axis direction by one pitch.

When the probe 4 moves from the surface of the object to be measured 2 to the surface of the green sheet 1 while performing coordinate measurement in this way, the reflected light (green) from the sheet 1 is absorbed by the filter 9 and reflected by the camera 8. reflected light is not captured. Therefore,
The control signal from the comparator 12 to the probe control circuit 6 becomes O (zero), the probe control circuit 6 reverses the moving direction of the probe 4, and the measurement on the surface of the object to be measured 20 starts again. Then, in the coordinate calculation circuit 13, drive information (X,
The shape (coordinates) of the object to be measured 2 is determined from the information on the amount of movement of the probe 4 in the directions of arrows A and A' (Z-axis).

Note that here, the relationship between the reflected light color and the filter 90 combination is such that they are absorbed by each other when subtractive color mixing is performed.

FIG. 2 explains the absorption relationship of subtractive color mixture.

For example, as shown in FIG. 2(a), red light is absorbed by the green sheet 1 and is not reflected.
The camera 8 does not capture the reflected light.

Similarly, as shown in FIG. 2(b), due to the absorption relationship between green and red, the reflected light (green) from the green sheet 1 under the white light source 3 is absorbed by the red filter 9. The camera 8 cannot capture the reflected light.

FIG. 3 shows a specific measurement example using the apparatus of this embodiment.

FIG. 3(a) shows the case where the three-dimensional object 31 to be measured was placed on the green sheet 32 as described above, and the measurement range could be controlled to only the three-dimensional object 31. Also the third
In Figure tb>, character line 3 on three-dimensional object 31
This shows a case where precise measurement is performed by limiting two neighborhoods. In this case, the vicinity of the character line 32 is covered with green adhesive tape 33.
By enclosing the area, the probe moved and measured only the enclosed area, allowing very efficient measurement control.

As described above, in this embodiment, there is no need to specify the measurement range by inputting coordinates in detail, and there is no need for unnecessary measurements such as when the measurement range is roughly approximated as a rectangle, making it extremely efficient and fast. The desired measurements can be made. Further, even if the object has a complicated shape, the same effect can be obtained by simply placing it on the sheet as in the embodiment.

A second embodiment of the present invention will be described below.

FIG. 4 shows a perspective view of a shape measuring device according to a second embodiment of the present invention. In FIG. 4, the difference from the configuration in FIG. 1 is that the contact probe 4 for coordinate measurement shown in FIG. This is a change. That is, this non-contact optical device 41 optically measures coordinates in the Z direction using an autofocus mechanism, etc., and the part corresponding to the camera has a red color similar to that in the first embodiment. filter 42
is installed. Therefore, the camera 8 for detecting reflected light as shown in FIG. 1 is unnecessary, and this single optical device 41 can be used for both purposes. The amount of focus adjustment on the Z axis by the autofocus mechanism of the optical device 41 is input to the coordinate calculation unit #13 shown in FIG.
axis) is provided with an optical device control circuit and an optical device drive circuit corresponding to the probe control circuit 6 and probe drive circuit 7 shown in FIG. Furthermore, the configurations of the sampling circuit 10 to the comparator 12 are the same, and the description thereof will be omitted.

When this optical device 41 was used, measurements as shown in FIG. 3 shown in the first embodiment could be carried out very efficiently. In particular, by using the optical device 41, the reflected light detection part and the coordinate measurement part, which are essential to the present invention, can be integrated.
We were able to make the shape measurement mechanism more compact without complicating it.

Note that the color, shape, material, etc. of the sheet 1.32 and the adhesive tape 33 for indicating the measurement area shown in the first and second embodiments of the present invention do not limit the present invention, and are not intended to limit the present invention. The surface of the object 20 may be directly colored, and the color may be determined by the absorption relationship by subtractive color mixture described in detail of the present invention, in consideration of the combination of the irradiation light to the object 2 and the filter for controlling reflected light. It is sufficient if it holds true.

In addition, in this example, the colors outside the measurement area are controlled by making them in an absorption relationship by subtractive color mixture to eliminate reflected light, but conversely, the colors inside the measurement area are made in an absorption relationship by subtractive color mixture to eliminate reflected light. A similar effect can be obtained by controlling the measurement direction of the coordinate measurement part when there is reflected light.Also, for character lines, areas where there is no reflected light can be precisely measured at particularly fine pitches using jt! It is also possible to control so as to set the I value. Furthermore, the expression (1, 0) of the binary signal of the comparator 12, the operation control in the X-axis and Y-axis directions of the probe control circuit 6, and the number of filters for controlling reflected light shown in this embodiment limit the present invention. It's not a thing. Further, the camera 8 for detecting reflected light may be any medium that transmits light, such as an optical fiber. It is also possible to use the following method.

As is clear from the invention, which goes beyond the effects of the invention, when specifying the measurement range for shape measurement, the conventional extremely complicated coordinate input work and wasteful and inefficient measurement due to near ω specification can be replaced with the irradiation light and the measured object. By selecting a combination of color components on the surface of an object and absorption by subtractive color mixing in a filter for controlling reflected light, this can be done very simply, efficiently, and at high speed.

Further, even if the shape of the object to be measured changes, there is no need to respecify the measurement range, and partial measurements such as character lines can be carried out very efficiently.

[Brief explanation of the drawing]

FIG. 1(a) is a perspective view showing a specific method of shape measurement in the first embodiment of the present invention, and FIG. figure,
FIGS. 5 and 6 are perspective views showing a conventional shape measurement control system. DESCRIPTION OF SYMBOLS 1... Sheet, 2... Measured object, 3... Light source, 4
... Probe, 5... Area setting circuit, 6... Probe control circuit, 7'-Probe drive circuit, 8... Camera, 9... Filter, 10... Sampling circuit,
11...Threshold value setting circuit, 12...Comparator, 13...
- Coordinate calculation circuit, 41... optical device. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 Figure (shi) Figure 2 (a) (b) Figure 3, ? ! <a> (g) Figure 4 Figure 5 Figure 6

Claims (6)

[Claims] (1) An object to be measured whose surface has a first color;
an area indicating member having a second color that indicates a measurement area of the object to be measured; a shape measuring means that measures a three-dimensional shape of the object; and one of the first and second colors. An optical system that has a filter in front that absorbs or reflects one side, and optically inputs reflected light from the light source of the object to be measured or the area indicating member in the shape measuring means currently being measured, and converts it into an electrical signal. and a control means for driving and controlling the position of the shape measuring means in accordance with the input level of an electrical signal from the optical means. (2) The shape measuring device according to claim 1, wherein the shape measuring means is a contact probe. (3) The shape measuring device according to claim 1, wherein the shape measuring means is a non-contact optical device. (4) The shape measuring device according to claim 1, wherein the shape measuring means and the optical means are the same non-contact optical device. (5) A shape measuring device according to any one of claims 2, 3, and 4, wherein the optical device measures the shape of the object to be measured in the Z-axis direction using an autofocus mechanism. (6) A sheet member on which the object to be measured of the area indicating member is placed;
Alternatively, the shape measuring device according to claim 1 is a tape member attached to the object to be measured.