JP2000018914A - Optical system round hole measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method of measuring the center position and the diameter of a round hole, in a short time. SOLUTION: A round hole 3 formed in a flange surface 5 and the flange surface except the round hole 3 are scanned with a laser spot 9. A first measurement line 22 set on the flange surface 5 is scanned with the laser spot 9. From the information of a reflected light which is detected, coordinates 28, 29 of both the first ends of the round hole 3 on the first measurement line 22 are obtained. A second measurement line 30 which is set so as to intersect the first measurement line 22 is scanned with the laser spot 9. From the information of a reflected light which is detected, coordinates 36, 37 of both the second ends of the round hole 3 are obtained. On the basis of the coordinates 28, 29 of both the first ends and coordinates 36, 37 of both the second ends, the center position and the diameter of the round hole 3 are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring a hole center position and a hole diameter of a round hole.

[0002]

2. Description of the Related Art Conventionally, a laser spot is scanned over a round hole and a measurement surface other than the round hole, and the hole center position and the hole diameter of the round hole are determined by using the reflected light of the laser spot reflected by the measurement surface. It is known to irradiate a measuring surface with a semiconductor laser beam, and continuously examine the intensity of the radiated light of the semiconductor laser while returning the reflected light to the light emitting portion of the semiconductor laser. Automatically measures the hole diameter and hole center position of a round hole (Japanese Patent Laid-Open No. 57-171).
No. 205).

[0003]

However, in the above-mentioned conventional measuring method, the entire surface of the round hole is scanned a plurality of times at predetermined intervals in one direction, and the distance between both ends of the round hole for each scan is detected. The maximum value of the distance between both ends is the hole diameter of the round hole, and then the hole diameter in the other direction orthogonal to the direction is similarly determined,
In order to know the hole center position from the coordinate positions of both ends of the round hole that determines the hole diameter in the one direction and the coordinate positions of both ends of the round hole that determine the hole diameter in the other direction, it takes a long time to measure the hole diameter and the hole center position. Is required. Then, this invention is made in order to solve such a problem, and makes it a subject to provide the optical round hole measuring method which can measure the hole diameter and hole center position of a round hole in a short time. .

[0004]

According to the present invention, a laser spot is scanned over a circular hole formed in an object to be measured and a measuring surface other than the circular hole, and reflected light of the laser spot reflected by the measuring surface is reflected. In the optical round hole measuring method of measuring the hole center position and the hole diameter of the round hole by using, the laser spot was detected by scanning the laser spot on a first measurement line passing through the round hole and a measurement surface other than the round hole. First coordinates of both ends of the round hole on the first measurement line are acquired from information of the reflected light, and the first measurement line passes through the round hole and a measurement surface other than the round hole, and From the information of the reflected light detected by scanning the laser spot on the intersecting second measurement line, second end coordinates which are coordinates of both ends of the round hole on the second measurement line are obtained, and the first end coordinates are obtained. A hole center position and a hole diameter of the round hole are obtained based on the second end coordinates.

[0005] From the first end coordinates and the second end coordinates obtained by the above method, a plane on which the first and second end coordinates are simultaneously located is determined, and a line segment connecting the first end coordinates to each other is determined on the plane. And the vertical bisector of the line connecting the second end coordinates to each other, and obtaining the coordinates of the intersection of these two vertical bisectors to obtain the hole center position of the round hole I do. The hole diameter can be obtained by obtaining and doubling the distance between the hole center coordinates and any one of the first and second end coordinates.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The first measurement line and the second measurement line may intersect inside the round hole or may cross outside the round hole. Both measurement lines may intersect on the line actually scanned, or may intersect outside the scanning range. First measurement line and second measurement line
Although the intersection angle with the measurement line is not particularly problematic, the intersection angle is desirably 10 to 170 °, and preferably 30 to 150 °, from the viewpoint of improving the measurement accuracy of the hole center position and the hole diameter.
Is more preferable, and more preferably 60 to 120 °.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a diagram showing the relationship between the center of the hole 3 and the diameter of the hole 3 formed in the outlet flange 2 of the exhaust manifold 1 using the laser distance sensor 4. It is a figure which shows the positional relationship of. The flange surface 5 of the outlet flange 2 is provided in parallel with the Y-axis direction indicated by the arrow in FIG. 1 and is provided with a slight inclination with respect to the Z-axis direction perpendicular to the Y-axis direction. The measurement surface 8 of the laser type distance sensor 4 faces the flange surface 5 and
It is arranged parallel to the axis. A light projecting unit 6 is provided above the measurement surface 8, a laser spot 9 projected from the light projecting unit 6 is reflected on the flange surface 5, and the reflected light is received by a light receiving unit 7 provided below the measurement surface 8. Is received at. The laser type distance sensor 4 is connected to a robot arm 12 (FIG. 2) via a fixed plate 10 and a connecting rod 11.

FIG. 2 is a block diagram showing a processing system for an output signal output from the laser distance sensor 4 shown in FIG. The signal of the reflected light received by the laser distance sensor 4 is input to the signal processing device 14 via the reflected signal line 13. The signal processing device 14 converts the input information into distance information between the laser distance sensor 4 and the flange surface 5,
The distance information is transmitted to the computer 1 via the distance signal line 15.
6 is output. The robot arm 12 to which the laser type distance sensor 4 is connected is connected to a robot arm control device 18 via a first control signal line 17. The robot arm controller 18 controls the movement of the robot arm 12 and outputs a control signal of the robot arm 12 to the computer 16 via a second control signal line 19. The computer 16 calculates the coordinate position of the laser spot projection part on the flange surface 5 based on the distance information input from the signal processing device 14 and the control information of the robot arm 12 input from the robot arm control device 18. And
The hole center position and the hole diameter of the round hole are acquired based on the calculation result. The computer 16 is connected to a monitor device 21 via a monitor signal line 20. The monitor device 21 displays various information such as the distance information, the coordinates of the laser spot projection area, the hole center position, the hole diameter, and the like input to the computer 16 as necessary.

Next, the optical round hole measuring method of the present invention will be described. Fixing device for exhaust manifold 1 (not shown)
Then, the laser spot 9 is projected onto the flange surface 5 from the light projecting portion 6 of the laser type distance sensor 4, and when the laser type distance sensor 4 is moved in the Y-axis direction, the laser spot 9 is rounded. The initial position of the laser type distance sensor 4 is set so as to pass over the area 3. The control information of the robot arm 12 at the initial position of the laser distance sensor 4 is output from the robot arm control device 18 to the computer 16, and the laser spot projection portion on the flange surface 5 at the initial position and the laser distance sensor 4 The distance information between the two is output from the signal processing device 14 to the computer 16 and the laser type distance sensor 4 is output based on the control information and the distance information.
At the initial position of the laser spot 9 on the flange surface 5 is determined, and the position is set as the coordinate origin.

Next, the robot arm 12 is controlled by the robot arm controller 18 to move the laser type distance sensor 4 along the Y axis in FIG. As shown in FIG.
The laser spot 9 is scanned on the first measurement line 22 parallel to the Y axis, and the light reflected by the laser spot 9 reflected by the flange surface 5 is received by the light receiving section 7 of the laser type distance sensor 4, and information on the reflected light is obtained. To the computer 16 via the signal processing device 14.
Output to

FIG. 4 shows information input from the signal processing device 14 to the computer 16. The horizontal axis of FIG. 4 is the elapsed time when the laser spot 9 is scanned on the first measurement line, and the vertical axis is the distance between the flange surface 5 and the laser distance sensor 4 at the spot where the laser spot 9 is projected. It is. In FIG. 4, a concave portion 23 is a portion where the light receiving portion 7 of the laser type distance sensor 4 cannot receive the reflected light, and is formed when scanning the round hole 3 portion. A pair of edge portions 24 and 25 at the upper end of the concave portion 23 indicate both end portions 26 and 27 of the round hole 3 on the first measurement line 22. In the computer 16, the robot arm 1 input from the robot arm control device 18
2 based on the information on the moving speed of the laser spot 2 and the information on the temporal change of the distance between the flange surface 5 and the laser distance sensor 4 input from the signal processing device 14, Are calculated, and both ends 26 of the round hole 3 on the first measurement line 22 are calculated.
First end coordinates 28 and 29, which are position coordinates of 27, are acquired.

After the scanning of the laser spot 9 on the first measurement line 22 is completed, the laser spot 9 is scanned on a second measurement line 30 parallel to the Z axis, and the laser spot 9 reflected on the flange surface 5 is scanned. The reflected light is received by the light receiving section 7 of the laser type distance sensor 4, and information on the reflected light is output to the computer 16 via the signal processing device 14.

FIG. 5 shows information input from the signal processing device 14 to the computer 16. The horizontal axis in FIG. 5 is the elapsed time when the laser spot 9 is scanned on the second measurement line 30 of the flange surface 5, and the vertical axis is the distance between the flange surface 5 and the laser type distance sensor at the spot where the laser spot 9 is projected. 4. In FIG. 5, a concave portion 31 is a portion where the light receiving portion 7 of the laser type distance sensor 4 cannot receive the reflected light, and is formed when scanning the round hole 3 portion. Recess 31
A pair of edge portions 32 and 33 at the upper end indicate both end portions 34 and 35 of the round hole 3 on the second measurement line 30. In the computer 16, information on the moving speed of the robot arm 12 input from the robot arm control device 18 and information on the temporal change in the distance between the flange surface 5 and the laser distance sensor 4 input from the signal processing device 14. And from
The position coordinates of the light projecting part with respect to a preset coordinate origin are calculated, and both ends 3 of the round hole 3 on the second measurement line 30 are calculated.
The second end coordinates 36 and 37 which are the position coordinates of 4 and 35 are acquired.

In the computer 16, the first end coordinate 2
8, 29 and the second end coordinates 36, 37,
A plane including the two end coordinates 28, 29, 36, and 37 is determined. On this plane, a vertical bisector 38 of a line connecting the first end coordinates 28 and 29 and the second end coordinates 36, 3
7 is obtained, and the intersection of these two perpendicular bisectors 38 and 39 is obtained to obtain the hole center coordinates 40 of the round hole 3 as the hole center position. Hole center coordinates 40 and first end coordinates 28, 29 or second
One of the coordinates 36, 37 at both ends (FIG. 3
By calculating the distance to the coordinates 37) and doubling it,
The pore size can be obtained.

[0015]

According to the present invention, a laser spot is scanned over a circular hole formed in an object to be measured and a measurement surface other than the circular hole,
In the optical round hole measuring method for measuring the hole center position and the hole diameter of the round hole using the reflected light of the laser spot reflected on the measurement surface, a method of passing the round hole and a measurement surface other than the round hole through the measurement surface. A first end coordinate which is a coordinate of both ends of the round hole on the first measurement line is obtained from information of the reflected light detected by scanning the laser spot on one measurement line, and a first end coordinate other than the round hole is obtained. From the information on the reflected light detected by scanning the laser spot on a second measurement line passing through the measurement surface and intersecting with the first measurement line, the coordinates of both ends of the round hole on the second measurement line are obtained. (2) The coordinates of both ends are obtained, and the hole center position and the hole diameter of the round hole are obtained based on the first end coordinates and the second end coordinates, so that the hole center position and the hole diameter can be measured in a short time. Therefore, automatic measurement of the hole center position and the hole diameter can be put to practical use.

[Brief description of the drawings]

FIG. 1 is a diagram showing a measuring apparatus and an object to be measured used for explaining a measuring method according to an embodiment of the present invention.

FIG. 2 is a block diagram of a signal processing system used in the measurement method of the embodiment.

FIG. 3 is a diagram illustrating a geometric analysis method used in the measurement method of the embodiment.

FIG. 4 is a diagram showing output characteristics when a laser distance sensor in the measuring device of FIG. 1 is moved in the Y-axis direction.

FIG. 5 is a diagram showing output characteristics when a laser distance sensor in the measuring device of FIG. 1 is moved in the Z-axis direction.

[Explanation of symbols]

 3 Round Hole 5 Flange Surface 9 Laser Spot 22 First Measurement Line 28, 29 First End Coordinates 36, 37 Second End Coordinates

Claims (1)

[Claims] 1. A laser spot is scanned over a round hole formed on an object to be measured and a measurement surface other than the round hole, and the center of the hole of the round hole is determined using reflected light of the laser spot reflected by the measurement surface. An optical round hole measuring method for measuring a position and a hole diameter, wherein the first spot is scanned from the information of reflected light detected by scanning the laser spot on a first measurement line passing through the round hole and a measurement surface other than the round hole. A first end coordinate, which is a coordinate of both ends of the round hole on the measurement line, is obtained, and the coordinates are obtained on a second measurement line passing through the round hole and a measurement surface other than the round hole and intersecting with the first measurement line. From the information of the reflected light detected by scanning the laser spot, the second
Acquiring second end coordinates which are coordinates of both ends of the round hole on a measurement line, and obtaining a hole center position and a hole diameter of the round hole based on the first end coordinates and the second end coordinates. Optical round hole measurement method.