JP3381420B2 - Projection detection device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a projection such as a burr on a cylindrical object in a non-contact manner. 2. Description of the Related Art In the process of manufacturing a cylindrical casting, burrs often occur on the side surface, and it is necessary to remove the burrs by some method. In this case, it is known that burrs are generated at two places at 180 ° intervals on the outer periphery of the cylindrical object. The mainstream of burr detection is to perform visual inspection.
As a result, they are often overlooked, which affects downstream processes of the production line. Therefore, an automatic flash detection device that replaces the visual inspection is being developed. As an example of a flash detection device, Japanese Patent Application Laid-Open
In Japanese Patent Application Laid-Open No. 1-152580, there is a method of detecting burrs by previously capturing non-defective data as a two-dimensional image and superimposing the data on a captured object, and describes a method of superimposing the burrs. As another example, Japanese Patent Application Laid-Open No. H04-110708 discloses that an object is irradiated with a laser beam, and the specularly reflected light is received by a photodiode. There is a method of detecting burrs by changing the amount of light received. [0004] However, in the above-described method of capturing non-defective data in a two-dimensional image in advance and superimposing the data on a captured object to detect burrs, both methods are used. The operation to exactly overlap the shapes is complicated, and in order to perform a burr inspection of various parts, it is necessary to have data of good parts as many as the number of parts, and it is necessary to first recognize which parts are There was a problem. Irradiate the object with laser light,
The specular reflection is received by the photodiode, and if there is a burr, the burr is irregularly reflected.Therefore, the method of detecting the burr by changing the amount of light received by the photodiode is described in the case where the object is a cylindrical object. It is actually difficult to arrange the photodiode at a position where the specular reflection component returns. The present invention solves the above-mentioned problems of the prior art, and enables labor saving of deburring work. [0005] [0006] The present invention in order to achieve this purpose, a slit light source for emitting a slit light, circle the slit light
A slit scanning means for scanning and irradiating the both side surfaces of the cylindrical object, an imaging unit for imaging the scattered light obtained by reflection from the said cylindrical object by scanning the slit light, the signal from the imaging means Position calculating means for calculating the position of the scattered light on the imaging surface of the imaging means, and the cylindrical object
Region setting means for setting a region on an object , and coarse and dense positions of the scattered light on both side surfaces of the cylindrical object in the region
And the density of a cylindrical object without protrusions
And a coarse / dense discriminating means for discriminating the projections. According to the present invention, firstly, the object is irradiated with slit light and the scattered light obtained by reflection from the object is guided to the position detecting means by a condenser lens. The scattered light condensing position on the position detecting means that changes according to the height unevenness is detected, and three-dimensional data of the object surface is obtained from the signal by the shape calculating means. The interval calculating means, the change calculating means, and the shape identifying means detect projections such as burrs at high speed and with high accuracy. Second, slit light is applied to the object from both sides of the position detecting means, and scattered light obtained by reflection from the object is guided to the position detecting means by a condenser lens, and the height of the object on the object is reduced. The scattered light condensing position on the position detecting means which changes in accordance with the unevenness is detected, and the projections such as burrs and the like are detected at high speed and high precision by the difference calculating means and the coarse / fine identification means in each of the elongated areas set from the position. (Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a projection detecting device according to a first embodiment of the present invention. In FIG. 1, 10
1 and 102 are laser slit light sources, 103 and 1
04 is a slit scanning means, 105 and 106 are slit lights, 107 is an object, and 108 is an object setting means. Reference numeral 109 denotes an imaging unit. Further, as components of the imaging unit, 110 is a condenser lens, 111 is a position detection unit, and 112 is a light receiving unit. Laser slit light source 10
1 and the slit scanning means 103 are arranged below the position detecting means 111, and the laser slit light source 102 and the slit scanning means 104 are arranged at symmetrical positions above the position detecting means 111. Further, 113 and 114 are photocurrent signals from the light receiving means 112, 115 is a shape calculation means for calculating three-dimensional shape information from the photocurrent signal, 116 is a control MPU for controlling the whole, and 117 is a slit scanning means 103
Scanner control driver for controlling
Is an MPU bus. Further, as components of the shape calculation means 115, 119 is an I / V conversion means for converting a photocurrent signal into a voltage signal, 120 is an A / D conversion means for converting a voltage signal into a digital signal, and 121 is a digital signal which is primary. Are stored in the memory A, 122 are position calculating means, 12
Reference numeral 3 denotes a coordinate calculation means for calculating a three-dimensional shape; 124, a memory B for storing the results of the shape calculation; and 125, a data integration means. Reference numeral 126 denotes burr detection means A, and 127 is a region setting means, 128 is a maximum value detection means, 129 is an interval calculation means, 130 is a change calculation means, and 131 is a shape identification means. is there. FIG. 2 is a structural diagram of the position detecting means 111 constituting the image pickup surface of the light receiving means 112. An imaging surface is formed by arranging 128 non-segmented one-dimensional optical position detection sensors 201 in the short side direction. In this embodiment, the non-segmented one-dimensional optical position detection sensor 201 has a PSD (Position Sensitivity).
tive Detector).
The incident position of the scattered light of the slit light from the object incident on the PSD can be obtained by utilizing the characteristic that the current flowing through the electrodes 202 and 203 at both ends of the element is inversely proportional to the distance between the electrodes. That is, position data can be calculated from the currents I1 and I2 flowing through the two electrodes 202 and 203 using the equation (1). Position data = K · (I1−I2) / (I1 + I2) (1) where K is a coefficient for normalization. FIG. 3 shows the principle of triangulation, which is the basic measurement principle for measuring the three-dimensional shape of an object with the projection detection device of the present invention. As shown in FIG.
01 is applied to the point P402 on the object, and the reflected light 403 at that time is imaged by the imaging means 404. At this time, the amount of movement of the image on the screen 405 of the imaging means 404 caused by the unevenness of the surface of the object is extracted, so that the baseline A
The intersection angles .theta.b and .theta.d between B406 and the reflected light 403 are obtained, and these values and the irradiation angle of the laser beam 401, that is, the intersection angles .theta.a and .theta.c between the base line AB406 and the laser beam 401 and the base line AB406. The three-dimensional coordinate information of the object surface can be obtained from the length L. [0014] Figure 4 is a graph showing with the burr can be strip-like region of the cylindrical object 107, (a) is a perspective view,
(B) is a top view. Reference numeral 501 denotes a band-like area where burrs can occur. As shown by the arrow in FIG.
There are several places. The operation of the projection detecting device configured as described above will be described below. The object 10 set on the object setting means 108 by the slit light 105 by the laser slit light source 101 and the slit scanning means 103
7. Irradiate on top. The scattered light reflected from above the object 107 by the irradiation of the slit light 105
Then, an image is picked up by the light receiving means 112 composed of a plurality of arrayed position detecting means 111. The photocurrent signals 113 and 114 from the position detecting means 111 are converted into voltage signals by the I / V converting means 119, respectively, and further converted into digital signals by the A / D converting means 120 at a predetermined timing signal in about 128 μs per slit. Converted and stored in memory A1
21 is written. Then, the scanner control driver 1
The slit light 105 is moved to a different position on the object 107 by the slit scanning means 103 according to the control signal from 17 and the signal processing up to the memory A121 is repeated to scan the entire surface of the object 107 in about 33 ms. Next, based on the digital signal for each one-dimensional light position detecting element (PSD) of each slit, the position calculating means 122 calculates the scattered light incident position of each PSD for each slit based on equation (1). This is used as the position signal of the measurement point, and the coordinate calculation means 123 calculates the three-dimensional shape information of each measurement point of the object 107 with respect to a predetermined coordinate system based on the principle of triangulation shown in FIG. Written. After irradiating the slit light 105 from the laser slit light source 101 and the slit scanning means 103 as described above and obtaining a three-dimensional coordinate measurement result at each measurement point, this time, the laser slit light source 102 and the slit scanning means 104 The slit light 106 is irradiated on the object 107. Also in this case, the three-dimensional coordinate calculation is performed in the same flow of operation as the case of the irradiation of the slit light 105 by the laser slit light source 101 and the slit scanning means 103 described above, and the memory B
124 is written. As described above, when the three-dimensional coordinate calculation from both directions is completed, the data integrated means 125 integrates the data measured from both directions to reduce a blind spot area. Further, referring to FIG.
Will be described. In FIG. 5A, the cylindrical object 1
At 07 (the radius of the circle may be different depending on the location), an area such as 601 is set by the area setting means 127, and the measurement data is divided for each set area. Since this region is very elongated, the radius of the circle of the object in the region is the same. FIG. 5B is a cross-sectional view of a region 601 of the target object, showing a state where burrs are present. In this area, the height data is compared by 128 maximum value detecting means, and the maximum value 602 of the value in the height direction is detected. This maximum value 602 is the vertex of the burr when there is a burr, and is the data on the strip-like area where the burr can occur because the object is cylindrical if there is no burr. The height obtained by subtracting a plurality of set values from the maximum value 602 becomes each of 603, and the distance between the objects at each of the heights 603 is obtained by the distance calculating means 129. Then, the change calculating means 130 calculates the change of the interval 604 from the higher one by using the difference, and the interval is narrower than both the characteristics of the interval obtained by the interval calculating means 129 and the change obtained by the change calculating means 130. , Which does not change much are detected as burrs by the shape identification means 131. As described above, according to the present embodiment, the position detecting means having the imaging surface formed by arranging a plurality of non-divided one-dimensional light position detecting elements in the short side direction thereof, and the one-dimensional light Two sets of slit light sources and slit scanning means arranged on both sides in the long side direction of the position detecting element, and scattered light obtained by reflecting from the object by irradiating the slit light is condensed on the position detecting means by a condensing lens. A light receiving means for outputting a photocurrent signal, a shape calculating means having a position calculating means, a coordinate calculating means and a data integrating means, and a device controlling means for controlling the whole system reduce the blind spot area and reduce the surface of the object. Height data can be acquired at high speed and with high accuracy, the three-dimensional coordinates of each object are divided into regions by the region setting means, and the maximum value is detected by the maximum value detecting means for each region, and a plurality of values are set from this value. Within height range Interval determined by interval calculating means, and further seeking changes in the interval by the change computing means, by the shape identification means can detect the protrusion of burrs. (Embodiment 2) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a block connection diagram of the protrusion detection device according to the second embodiment of the present invention. FIG. 1 shows the configuration of a projection detecting device according to a first embodiment of the present invention.
Reference numeral 126 denotes an imaging position calculation unit 701 and a burr detection unit B70
The configuration and operation other than the configuration 3 are the same as those of the first embodiment of the present invention, and the configuration diagram and the operation description are omitted. Reference numeral 701 denotes an imaging position calculation means. Further, as components of the imaging position calculation means, I / V conversion means for converting a photocurrent signal of 119 into a voltage signal, and A / V for converting a voltage signal of 120 into a digital signal. The position conversion means of the memories A and 122 of the D conversion means 121 are the same as those of the first embodiment of the present invention, and 702 is a memory C for storing the result of the position calculation means. Reference numeral 703 denotes a burr detection unit B, and a region setting unit 127 as a component of the burr detection unit B is the same as that of the first embodiment of the present invention.
Is a difference calculating means, and 705 is a coarse / fine identification means . The operation of the projection detecting device configured as described above will be described below. Position calculation means 122
At each one-dimensional light position detecting element (PS
The process of calculating the scattered light incident position of each PSD in each slit based on the equation (1) based on the digital signal for each D) and using the calculated position as the position signal of the measurement point is the first embodiment of the present invention. The description is omitted because it is the same as that of the embodiment. Next, the result of the position calculation means 122 is written into the memory C702. As described above, after irradiating the slit light 105 from the laser slit light source 101 and the slit scanning means 103 and obtaining the position signal of each measurement point, the slit light 1 is then emitted by the laser slit light source 102 and the slit scanning means 104.
06 is irradiated on the object 107. Also in this case, the processing flow is the same as that of the first embodiment of the present invention, where the position calculation is performed and the result is written into the memory C702. As described above, when the position calculation from both directions is completed, each one-dimensional PS is set in each of the areas set by the area setting means 127 (if the one-dimensional PS is set in a band-like area where the object can generate burrs).
(If D is set so that the long side direction is vertical, the area will be for each one-dimensional PSD.) The difference calculation means 704 allows the strip-shaped area of the position data, which is sequentially calculated according to the slit scanning, to generate burrs. Calculate the difference in the direction substantially perpendicular to. The operation of the coarse / fine identification means 705 will be described with reference to FIG. FIG. 7A is a conceptual diagram of an optical system of the protrusion detection device according to the present embodiment. (B) and (c) sequentially irradiate the slit light 105 onto the object 107 by the laser slit light source 101 and the slit scanning means 103,
The scattered light incident position when the scattered light hits a certain area set by the area setting means 127 is determined by the position calculating means 12.
This is a result in which all the measurement points scanned over the entire surface are indicated by straight lines parallel to the short side direction of the area. (B) shows the case where the burr was in that area, and (c) shows the case where there was no burr. (D) and (e) are results obtained by sequentially irradiating the slit light 106 onto the object 107 by the laser slit light source 102 and the slit scanning means 104 and performing the same processing. (D) is the same region as (b), and (e) is the same region as (c). The left ends of the regions (b) to (e) correspond to the upper ends of the position detecting means 111 in FIG. As shown in (b) to (e), the density state of the scattered light incident position changes depending on the presence or absence of burrs, so that the density identification means 705 detects the protrusions such as burrs based on the difference obtained by the difference calculation means 704. I do. As described above, according to the present embodiment, the position detecting means having the image pickup surface constituted by arranging a plurality of non-divided one-dimensional light position detecting elements in the short side direction thereof, Two sets of slit light sources and slit scanning means arranged on both sides in the long side direction of the position detecting element, and scattered light obtained by reflecting from the object by irradiating the slit light is condensed on the position detecting means by a condensing lens. A light receiving means for outputting a photocurrent signal; an imaging position calculating means having a position calculating means; a device controlling means for controlling the whole system; An area setting means to be set, and a difference for calculating a difference in a direction substantially perpendicular to a strip-like area in which burrs can be generated on an object of position data sequentially calculated in accordance with slit light scanning by position calculation means in each area. And calculation means, it is possible to detect the protrusion of burrs or the like by density identifying means for identifying the burrs from the results of the difference calculation means. As described above, according to the present invention, first, a projection such as a burr is detected by calculating three-dimensional coordinates of an object and identifying the shape of the object from the result. Therefore, it is possible to quickly and accurately detect a projection such as a burr without performing complicated operations and settings as in the related art. Secondly, since the projections such as burrs are detected based on the density of the reflected light from the object, the detection of the projections such as burrs can be performed without complicated operation or setting as in the related art. It can be performed quickly and accurately.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a projection detecting device according to a first embodiment of the present invention. FIG. 2 is a detailed diagram of a position detecting means according to the first embodiment of the present invention. FIG. 4 is a schematic view showing the principle of surveying. FIG. 4 is a conceptual diagram showing locations where burrs occur. FIG. 5 is a burr detecting means A in the first embodiment of the present invention.
FIG. 6 is a block diagram of a burr detecting device according to a second embodiment of the present invention. FIG. 7 is a burr detecting means B according to a second embodiment of the present invention.
101 Laser slit light source 102 Laser slit light source 103 Slit scanning means 104 Slit scanning means 105 Slit light 106 Slit light 107 Object 108 Object setting means 109 Imaging means 110 Condensing lens 111 Position detecting means 112 Light receiving means 113 Photocurrent signal 114 Photocurrent signal 115 Shape calculation means 116 Control MPU 117 Scanner control driver 118 MPU bus 119 I / V conversion means 120 A / D conversion means 121 Memory A 122 Position calculation means 123 Coordinate calculation Means 124 Memory B 125 Data integration means 126 Burr detection means A 127 Area setting means 128 Maximum value detection means 129 Interval calculation means 130 Change calculation means 131 Shape identification means

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-6-94637 (JP, A) JP-A-5-99639 (JP, A) JP-A-6-229928 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G01B 11/00-11/30 G01N 21/88

Claims (1)

(57) [Claim 1] A slit light source for emitting slit light,
A slit scanning unit that irradiates and scans both side surfaces of the cylindrical object with the slit light, an imaging unit that captures scattered light obtained by reflecting from the cylindrical object by scanning the slit light, and and position calculating means for calculating the position of the scattered light on an imaging surface of the imaging means by a signal from the means, and area setting means for setting an area on the cylindrical object Butsujo, the cylindrical subject in the region Cylinders that do not have the density of the scattered light on both side surfaces of the object and the protrusions obtained in advance
By comparing the density of Jo object projection detecting apparatus and a density identifying means for identifying a protrusion.