JP7153514B2 - 3D shape inspection device, 3D shape inspection method, 3D shape inspection program, computer - Google Patents

Description

The present invention relates to technology for determining the presence or absence of shape defects in an object.

2. Description of the Related Art Conventionally, there has been known an inspection apparatus that determines the presence or absence of shape defects in an object based on an image of the object. For example, the inspection apparatus described in Patent Document 1 detects the presence or absence of shape defects based on comparison between a reference image showing a non-defective product, which is an object having no shape defects, and an inspection image obtained by imaging the object. judge.

JP 2015-068668 A

By the way, in the above inspection based on a two-dimensional image, it may not be possible to accurately determine the presence or absence of a shape defect. For example, in the inspection of a relatively flat region of an object such as a forged product, unevenness caused by impact, that is, a dent is detected as a shape defect. At this time, in order to determine whether the dents pose a problem for the quality of the object, the depth of the dents in the depth direction of the image may be more important than the area of the dents appearing in the captured image. . On the other hand, the depth of the dent cannot be accurately grasped from the two-dimensional image.

In other words, in a two-dimensional image, since there is no information in the direction that is important for determining the presence or absence of a shape defect, such determination may not be performed accurately. Therefore, a method of determining the presence or absence of a shape defect based on the difference between the measurement data that is the result of measuring the three-dimensional shape of the surface of the object and the non-defective product data that indicates the three-dimensional shape of the surface of a non-defective product. can be considered.

The calculation of the difference between the measurement data and the non-defective product data is performed by aligning the positions of the three-dimensional shapes indicated by each data and extracting these differences. At this time, if the alignment of the three-dimensional shape indicated by each data is not accurate, there is a possibility of erroneously determining that a difference exists in a portion where the difference originally does not exist. In other words, in the example of the forged product described above, walls that are steeply inclined in the depth direction or parallel to each other may be present at the edges and steps of the good forged product. On the other hand, if there is a misalignment of the three-dimensional shape indicated by each data in the direction orthogonal to the depth direction, a large difference occurs near the wall surface. Therefore, it cannot be determined whether the difference indicates a wall surface that originally exists in a non-defective product or a shape defect.

The present invention has been made in view of the above problems, and in determining the presence or absence of a shape defect based on the difference in a predetermined direction that occurs between the measurement data and the non-defective product data, distinguishing from the wall surface that originally exists in the object, An object of the present invention is to provide a technique that enables accurate determination of the presence or absence of a shape defect.

A three-dimensional shape inspection apparatus according to the present invention includes an imaging unit for imaging an object, and data for obtaining measurement data by measuring the three-dimensional shape of the surface of the object based on the result of imaging the object by the imaging unit. The acquisition unit compares the measurement data with non-defective product data indicating the three-dimensional shape of the surface of a non-defective product, thereby determining the position of the surface of the object indicated by the measurement data and the position of the non-defective product indicated by the non-defective product data. A difference calculation unit that calculates a difference in a predetermined direction from the position of the surface, and a surface area of the non-defective product indicated by the non-defective product data, except for the wall surface area that forms an acute angle with respect to the predetermined direction that is smaller than the predetermined angle or that is parallel to the predetermined direction. a pass/fail judgment unit that judges whether or not there is a shape defect in the object based on the difference in the object region.

A three-dimensional shape inspection method according to the present invention compares measurement data, which is the result of measuring the three-dimensional shape of the surface of an object, with non-defective product data indicating the three-dimensional shape of the surface of a non-defective product. Thus, a step of obtaining a difference in a predetermined direction between the position of the surface of the object indicated by the measurement data and the position of the surface of the non-defective product indicated by the non-defective product data; determining whether or not there is a shape defect in the object based on the difference in the object region excluding the wall surface region where the acute angle formed by the two is smaller than the predetermined angle or parallel to the predetermined direction.

A three-dimensional shape inspection program according to the present invention compares measurement data, which is the result of measuring the three-dimensional shape of the surface of an object, with non-defective product data indicating the three-dimensional shape of the surface of a non-defective product without shape defects. Thus, a step of obtaining a difference in a predetermined direction between the position of the surface of the object indicated by the measurement data and the position of the surface of the non-defective product indicated by the non-defective product data; and determining whether or not there is a shape defect in the object based on the difference in the wall surface area in which the acute angle formed by the two is smaller than the predetermined angle or parallel to the predetermined direction.

A computer according to the present invention executes the three-dimensional shape inspection program described above.

The present invention (three-dimensional shape inspection device, three-dimensional shape inspection method, three-dimensional shape inspection program, computer) configured as described above provides measurement data, which is the result of measuring the three-dimensional shape of the surface of an object, and shape It is compared with non-defective product data representing the three-dimensional shape of the surface of a non-defective product. As a result, a difference in a predetermined direction between the position of the surface of the object indicated by the measurement data and the position of the surface of the non-defective product indicated by the non-defective product data is obtained. be. That is, the presence or absence of a shape defect is determined based on the difference in a predetermined direction between the measurement data and the non-defective product data. At this time, on the surface of the non-defective product indicated by the non-defective product data, the presence or absence of a shape defect in the object is determined based on the difference in the target region excluding the wall surface region that forms an acute angle with respect to the predetermined direction smaller than the predetermined angle or is parallel to the predetermined direction. is determined. Therefore, it is possible to accurately determine the presence or absence of a shape defect by distinguishing it from the wall surface that originally exists in the object.

Further, the three-dimensional shape inspection apparatus may be configured so that the difference calculation unit does not calculate the difference for the wall surface area, but calculates the difference for the target area. This makes it possible to calculate the difference required to determine the presence or absence of shape defects while suppressing the amount of calculation.

Further, the pass/fail determination unit may configure the three-dimensional shape inspection apparatus so as to exclude, from the target region, a region in which the magnitude of the difference in the predetermined direction is less than a predetermined value from the determination target of the presence or absence of the shape defect. good. With such a configuration, it is possible to accurately determine the presence or absence of a shape defect by narrowing down the determination target of the presence or absence of a shape defect to a region in which a relatively large difference appears.

In addition, the pass/fail determination unit operates the three-dimensional shape inspection device so as to further exclude, from among the regions remaining as determination targets in the target region, regions having an area in a plane perpendicular to a predetermined direction that is less than a predetermined area from determination targets. may be configured. With such a configuration, it is possible to accurately determine the presence or absence of a shape defect by narrowing down the determination target of the presence or absence of a shape defect to a region having a relatively large area.

Further, the pass/fail determination unit extracts a region remaining as a determination target from among the target regions as a candidate region, approximates a peripheral region of the candidate region with a plane orthogonal to a predetermined direction, sets a reference plane, and sets a reference plane. The three-dimensional shape inspection apparatus may be configured to determine that a shape defect exists in the candidate area when the distance from the reference plane at the position where the candidate area is the farthest from the reference plane is equal to or greater than a threshold value. With such a configuration, it is possible to accurately determine whether or not there is a shape defect in the candidate area based on the reference plane that approximates the peripheral area of the candidate area.

Also, the pass/fail determination unit may configure the three-dimensional shape inspection apparatus so as to set different thresholds for each of a plurality of ranges included in the target region. With such a configuration, it is possible to accurately determine the presence of a shape defect based on an appropriate threshold value according to the location of the object.

As described above, according to the present invention, when determining the presence or absence of a shape defect based on the difference in a predetermined direction between the measurement data and the good product data, the shape defect is distinguished from the wall surface that originally exists in the object. It is possible to accurately determine the presence or absence of

The figure which shows typically an example of the three-dimensional shape inspection apparatus which concerns on this invention. FIG. 2 is a block diagram showing an example of an electrical configuration included in the three-dimensional shape inspection apparatus shown in FIG. 1; 4 is a flowchart showing an example of measurement processing for measuring the three-dimensional shape of an object; The figure which shows typically an example of each non-defective product data and measurement data. 4 is a flowchart showing an example of inspection processing for inspecting the presence or absence of shape defects in an object. FIG. 6 is a diagram schematically showing calculation contents in the inspection process shown in FIG. 5; FIG. 6 is a diagram schematically showing calculation contents in the inspection process shown in FIG. 5; FIG. 6 is a diagram schematically showing calculation contents in the inspection process shown in FIG. 5; FIG. 6 is a diagram schematically showing calculation contents in the inspection process shown in FIG. 5; FIG. 6 is a diagram schematically showing calculation contents in the inspection process shown in FIG. 5; FIG. 8 is a diagram showing a wrench as a different example of an object to which inspection processing is applied;

FIG. 1 is a diagram schematically showing an example of a three-dimensional shape inspection apparatus according to the present invention. This figure and the following figures appropriately show an XYZ orthogonal coordinate system in which the Z-axis direction is the vertical direction and the X-axis direction and the Y-axis direction are the horizontal directions. A three-dimensional shape inspection apparatus 1 includes a support table 2 that supports an object J, and an imaging unit 4 that measures the three-dimensional shape of the object J on the support table 2 and acquires point cloud data.

If the object J contains iron or the like and can be held by magnetic force, an electromagnet table can be used as the support table 2 . If the object J is made of resin or the like and cannot be held by magnetic force, a table that supports the object J by air suction or a chuck mechanism can be used as the support table 2 .

The imaging unit 4 has a camera 41 and a projector 42 . The camera 41 captures an image of the imaging range F by forming an image of light incident on the lens 411 from within the imaging range F (in other words, field of view) on the solid-state imaging device. The projector 42 emits a pattern of light to the imaging range F by modulating the light from the light source with a DMD (Digital Mirror Device) or the like.

FIG. 2 is a block diagram showing an example of an electrical configuration provided in the three-dimensional shape inspection apparatus shown in FIG. 1. As shown in FIG. As shown in FIG. 2 , the three-dimensional shape inspection apparatus 1 includes a controller 9 having an arithmetic section 91 , a storage section 92 , a communication section 93 and an imaging control section 94 . A computing unit 91 is a processor including a CPU (Central Processing Unit), a RAM (Random Access Memory), etc., and controls the entire apparatus. The storage unit 12 is configured by a HDD (Hard Disk Drive) and stores a measurement program Pm, an inspection program Pi, non-defective product data Dr, measurement data Dm, and the like. The contents of these various programs Pm, Pi and data Dr, Dm will be described later. The communication unit 93 takes charge of communication functions with external devices.

The imaging control section 94 measures the three-dimensional shape of the surface of the object J using the imaging unit 4 . Specifically, the imaging control unit 94 causes the camera 41 to capture an image of the object J within the imaging range F while irradiating the pattern from the projector 42 toward the object J on the support table 2, thereby irradiating the pattern. An image M is acquired by imaging the target object J. FIG. Such an image M includes a pattern deformed according to the three-dimensional shape of the surface of the object J. FIG. Further, the calculation unit 91 develops a data generation unit 911 therein by executing the measurement program Pm. Then, the data generation unit 911 generates point cloud data representing the three-dimensional shape of the object J based on the image M acquired by the imaging control unit 94 . Various methods such as a phase shift method and a spatial encoding method can be used as a specific method for measuring the three-dimensional shape of the object J based on an image of the object J captured while irradiating a pattern.

FIG. 3 is a flow chart showing an example of measurement processing for measuring the three-dimensional shape of an object. In the flow chart of FIG. 4, steps S101 to S103 are executed under the control of the imaging control unit 94, and step S104 is executed under the calculation of the data generation unit 911. FIG. In the measurement process, when viewed from the direction of the optical axis A of the camera 41, the object J on the support table 2 is captured within the imaging range F of the imaging unit 4, and the object J on the support table 2 is projected from the projector 42. A pattern is projected (step S101), and an image of the object J on which the pattern is projected is captured by the camera 41 (step S102). Then, it is confirmed whether or not imaging has been completed for all of the plurality of patterns that are different from each other (step S103). If imaging of all patterns has not been completed ("NO" in step S103), steps S101 and S102 are re-executed while changing the pattern to be projected onto the object J. FIG. On the other hand, if imaging of all patterns has been completed ("YES" in step S103), the three-dimensional shape of the surface of the object J is shown based on a plurality of images M containing each of these patterns. Point cloud data is created (step S104) and stored in the storage unit 92 as measurement data Dm. That is, the measurement data Dm is point cloud data representing the three-dimensional shape of the surface of the object J measured in the measurement process.

Further, the controller 9 shown in FIG. 2 executes inspection processing for determining whether or not there is a shape defect such as a dent on the surface of the object J based on the measurement data Dm. Specifically, the inspection program Pi defines the contents of the inspection process, and the calculation unit 91 executes the inspection program Pi to obtain a difference calculation unit 912 and a pass/fail determination unit 913 that perform calculations required for the inspection process. is expanded inside it. Also, the non-defective product data Dr used in the inspection process is stored in advance in the storage unit 92 . This non-defective product data Dr is point cloud data representing the three-dimensional shape of the surface of a non-defective product, which is the object J having no shape defect. The non-defective product data Dr may be point cloud data obtained by performing measurement processing on a non-defective product, or may be generated based on CAD (Computer-Aided Design) data of the object J. FIG.

FIG. 4 is a diagram schematically showing an example of non-defective product data and measurement data. The three-dimensional shape Sr of the surface of the object J indicated by the non-defective product data Dr (referred to as the “non-defective three-dimensional shape Sr” as appropriate) is a rectangular flat plate extending in the Y-axis direction. It has a notched outline. This non-defective product data Dr indicates the position of the non-defective product three-dimensional shape Sr on each XY coordinate in the Z-axis direction. On the other hand, the three-dimensional shape Sm of the surface of the measured object J indicated by the measurement data Dm (referred to as “measured three-dimensional shape Sm” as appropriate) is the top surface of the three-dimensional shape Sr indicated by the non-defective product data Dr, with the concave portion C facing upward. It has an outer shape that opens to the This measurement data Dm indicates the position in the Z-axis direction of the measured three-dimensional shape Sm at each XY coordinate. The object J shown in the figure is merely an example, and needless to say, the object to which the inspection process described below is applied is not limited to the example shown in the figure.

FIG. 5 is a flow chart showing an example of inspection processing for inspecting the presence or absence of a shape defect in an object, and FIGS. 6 and 7A to 7D are diagrams schematically showing calculation contents in the inspection processing shown in FIG. . In this inspection process, the presence or absence of dents on the relatively flat upper surface of the object J facing the camera 41 is inspected.

In step S201, the difference calculator 912 performs data matching between the non-defective product data Dr and the measurement data Dm. As shown in FIG. 7A, this data matching is performed by matching corresponding points (that is, points representing the same position) of the non-defective three-dimensional shape Sr and the measured three-dimensional shape Sm. This is an arithmetic process for performing alignment of the .

In step S202, the difference calculation unit 912 sets a mask for the wall region Rw of the aligned three-dimensional shapes Sr and Sm. Setting of such a mask is performed in two steps of specifying the existence range of the wall surface region Rw in the non-defective three-dimensional shape Sr and setting a mask for the wall surface region Rw. As shown in FIG. 6, the wall surface region Rw is a region in which the acute angle θa between it and the Z-axis direction is smaller than a predetermined acute angle θb (predetermined angle), or a region parallel to the Z-axis direction. The slope at each point of the non-defective three-dimensional shape Sr can be obtained, for example, by calculating the slope at each point. Moreover, the predetermined acute angle θb may be defined in the inspection program Pi, or may be set by the user.

The difference calculation unit 912 identifies the existence range of the wall surface region Rw by searching for the wall surface region Rw from the non-defective three-dimensional shape Sr. Then, the difference calculator 912 sets a mask in the existence range of the wall surface region Rw in the aligned three-dimensional shapes Sr and Sm. As a result, as shown in FIG. 7B, a mask is set on the wall surface region Rw hatched with oblique lines, and the wall surface region Rw is excluded from subsequent calculations. As a result, a relatively flat (in other words, parallel to the XY plane) flat region Rf is extracted from the aligned three-dimensional shapes Sr and Sm.

In step S203, the difference calculator 912 calculates the positional difference in the Z-axis direction between the aligned flat region Rf of the non-defective three-dimensional shape Sr and the flat region Rf of the measured three-dimensional shape Sm for each XY coordinate. In this way, the difference in the Z-axis direction between the position of the surface of the object J indicated by the measurement data Dm and the position of the surface of the non-defective product indicated by the non-defective product data Dr is obtained. The difference is approximately zero in a range relatively parallel to the XY plane orthogonal to the Z-axis direction, while in the concave portion C that does not exist in the non-defective product indicated by the non-defective product data Dr but exists on the object J indicated by the measurement data Dm. growing. As a result, as shown in FIG. 7C, a difference image Mc in which the three concave portions C are actualized is obtained.

In step S204, the pass/fail determination unit 913 extracts pixels whose differences are greater than or equal to a predetermined value. This step S204 is performed for the purpose of extracting the pixels related to the concave portion C by excluding flat areas from the difference image Mc.

In step S205, the quality determination unit 913 connects the pixels extracted in step S204 to set a connected region Rc. This is performed for the purpose of associating pixels belonging to the same concave portion C and distinguishing pixels belonging to different concave portions C by associating adjacent pixels in the XY coordinates. Therefore, in the example of FIG. 7C, a connecting region Rc is set for each of the three recesses C. As shown in FIG.

In step S206, the pass/fail determination unit 913 extracts, as candidate regions Rp, connected regions Rc having an area equal to or greater than a predetermined area on the XY plane. In the example of FIG. 7C, two connecting regions Rc out of three connecting regions Rc are extracted as candidate regions Rp1 and Rp2.

Subsequently, the pass/fail determination unit 913 resets the identification number I for identifying the candidate regions Rp1 and Rp2 to zero (step S207), and increments the identification number I (step S208). As a result, the candidate region Rp1 is set as an execution target for subsequent steps.

In step S209, the pass/fail determination unit 913 determines a reference plane L obtained by approximating the peripheral region of the candidate region Rp1 in the difference image Mc with a plane perpendicular to the Z-axis direction as a candidate region, as shown in the column "Rp1" in FIG. 7D. Set to Rp1. Such planar approximation can be performed, for example, by the method of least squares. Then, in step S210, the pass/fail determination unit 913 determines that the distance Z1 from the reference plane L at the position V1 (in other words, peak) where the candidate region Rp1 is the farthest from the reference plane L in the Z-axis direction is equal to or greater than the threshold value Zt. determine whether Here, since the distance Z1 is less than the threshold value Zt, the pass/fail determination unit 913 determines "NO" in step S210, and proceeds to step S211.

In step S211, it is determined whether the identification number I is equal to the number Ix (=2) of the candidate regions Rp. Here, since the identification number I is "1", "NO" is determined in step S211. As a result, the process returns to step S208 and the identification number I is incremented. As a result, the candidate region Rp2 is set as an execution target for subsequent steps.

In step S209, the pass/fail determination unit 913 sets the reference plane L obtained by approximating the peripheral region of the candidate region Rp2 in the difference image Mc with a plane orthogonal to the Z-axis direction to the candidate region, as shown in the column of "Rp2" in FIG. 7D. Set to Rp2. Then, in step S210, the pass/fail determination unit 913 determines that the distance Z2 from the reference plane L at the position V2 (in other words, peak) where the candidate region Rp2 is the farthest from the reference plane L in the Z-axis direction is equal to or greater than the threshold value Zt. determine whether Here, since the distance Z2 is equal to or greater than the threshold value Zt, the pass/fail determination unit 913 determines "YES" in step S210, and determines that the candidate region Rp1 has a defective shape (dent) (step S212). ).

By the way, if all the candidate regions Rp extracted in step S206 are judged to be "NO" in step S210, the good/bad judgment unit 913 judges that the object J does not have a defective shape, and performs a good product judgment. (Step S213).

In the embodiment described above, the measurement data Dm, which is the result of measuring the three-dimensional shape Sm of the surface of the object J, and the non-defective product data Dr representing the three-dimensional shape Sr of the surface of a non-defective product having no shape defects. They are compared (steps S201 and S203). As a result, the difference in the Z-axis direction between the position of the surface of the object J indicated by the measurement data Dm and the position of the surface of the non-defective product indicated by the non-defective product data Dr is obtained (step S203). The presence or absence of a shape defect in J is determined (step S210). In other words, the presence or absence of a shape defect is determined based on the difference in the Z-axis direction between the measurement data Dm and the non-defective product data Dr. At this time, among the surface of the non-defective product indicated by the non-defective product data Dr, based on the difference in the flat region Rf excluding the wall surface region Rw in which the acute angle θa formed with the Z-axis direction is smaller than the predetermined acute angle θb or parallel to the Z-axis direction, It is determined whether or not there is a shape defect in the object J (steps S202, S203, S210). Therefore, it is possible to accurately determine whether or not there is a shape defect by distinguishing it from the wall surface that originally exists on the object J.

Further, the difference calculator 912 does not calculate the difference for the wall surface area Rw, but calculates the difference for the flat area Rf (steps S202 and S203). As a result, it is possible to calculate the difference (that is, the difference in the flat region Rf) required to determine the presence or absence of the shape defect while suppressing the calculation amount of the difference calculation unit 912 .

In addition, the pass/fail determination unit 913 excludes areas where the magnitude of the difference in the Z-axis direction is less than a predetermined value in the flat areas Rf from objects for determination of the presence or absence of shape defects (step S204). With such a configuration, it is possible to accurately determine the presence or absence of a shape defect by narrowing down the determination target of the presence or absence of a shape defect to a region in which a relatively large difference appears.

In addition, the pass/fail determination unit 913 further excludes, from among the connected regions Rc remaining as the determination targets in the flat region Rf, the connected regions Rc whose area on the XY plane perpendicular to the Z-axis direction is less than a predetermined area ( step SS206). With such a configuration, it is possible to accurately determine the presence or absence of shape defects by narrowing down the determination target of the presence or absence of shape defects to the connection region Rc having a relatively large area.

Further, the pass/fail judging unit extracts the connecting regions Rc remaining as the object of judgment from the flat regions Rf as candidate regions Rp1 and Rp2 (step S206), and extracts the peripheral regions of the candidate regions Rp1 and Rp2 perpendicularly to the Z-axis direction. A reference plane L is set by approximation on the XY plane. Then, when the distances Z1 and Z2 from the reference plane L at the positions V1 and V2 where the candidate regions Rp1 and Rp2 are farthest from the reference plane L in the Z-axis direction are equal to or greater than the threshold value Zt, a shape defect exists in the candidate region Rp1. Then judge. With such a configuration, it is possible to accurately determine whether or not there is a shape defect in the candidate regions Rp1 and Rp2 based on the reference plane L that approximates the peripheral regions of the candidate regions Rp1 and Rp2.

In the embodiment described above, the three-dimensional shape inspection apparatus 1 corresponds to an example of the "three-dimensional shape inspection apparatus" of the present invention, the controller 9 corresponds to an example of the "computer" of the present invention, and the inspection program Pi is It corresponds to an example of the "three-dimensional shape inspection program" of the present invention, the imaging unit 4 corresponds to an example of the "imaging unit" of the present invention, and the imaging control section 94 corresponds to an example of the "data acquisition section" of the present invention. The difference calculation unit 912 corresponds to an example of the "difference calculation unit" of the present invention, the pass/fail determination unit 913 corresponds to an example of the "pass/fail determination unit" of the present invention, and the measurement data Dm corresponds to the "measurement data , the good product data Dr corresponds to an example of the “good product data” of the present invention, the three-dimensional shapes Sm and Sr correspond to examples of the “three-dimensional shape” of the present invention, and the Z-axis direction corresponds to an example of the “three-dimensional shape” of the present invention. The wall region Rw corresponds to an example of the "predetermined direction" of the invention, the flat region Rf corresponds to an example of the "target region" of the invention, and the candidate region Rp1, Rp2 corresponds to an example of the "candidate area" of the present invention, and the reference plane L corresponds to an example of the "reference plane" of the present invention.

The present invention is not limited to the above-described embodiments, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, as described above, the object to which the inspection process of FIG. 5 is applied is not limited to the object J described above. Therefore, inspection processing may be performed using a wrench shown below as the object J. FIG.

FIG. 8 is a diagram showing a wrench as a different example of an object to which inspection processing is applied. In particular, FIG. 8 shows the difference image obtained by performing steps S201-S203 of FIG. 5 for spanners. In this differential image, the wall area Rw is shown in dark gray and the flat area Rf is shown in lighter gray. Further, white circle marks are also shown for shape defects (dents) detected by executing steps S204 to S212. In the flowchart of FIG. 5, when one shape defect is detected ("YES" in step S210), a defect judgment is made (step S212) and the process ends. After step S212, the process proceeds to step S211, which corresponds to the result of executing the pass/fail determination for all the candidate regions Rp.

Incidentally, in the object J such as the wrench shown in FIG. 8, for example, the mouth part on the left side of the neck step and the handle part on the right side may have different tolerances for shape defects. Therefore, the threshold value Zt used in step S210 may be different between the flat region Rf1 on the left side of the step and the flat region Rf2 on the right side of the step. In this case, the pass/fail determination unit 913 sets a different threshold value Zt for each of the multiple ranges Rf1 and Rf2 included in the flat region Rf. With such a configuration, it is possible to accurately determine the presence of a shape defect based on an appropriate threshold value Zt according to the location of the object J in step S209.

Also, the steps of the flowchart of FIG. 5 can be omitted as appropriate. For example, steps S204 to S209 may be omitted, and if there is a difference equal to or greater than a predetermined threshold value Zt in the difference image calculated in step S203, a defect determination may be performed.

Also, in the above example, quality determination is performed for a shape defect having a concave shape, but the inspection process of FIG. 5 can be used in the same way in performing quality determination for a shape defect having a convex shape.

Also, the function of performing inspection processing may be made independent of the three-dimensional shape inspection apparatus 1 . Specifically, the imaging control unit 94 and the measurement program Pm may be moved from the controller 9 to another computing device of the three-dimensional shape inspection apparatus 1 to make the controller 9 independent from the three-dimensional shape inspection apparatus 1 . Alternatively, by installing the inspection program Pi in a personal computer, a computer that executes inspection processing independently from the three-dimensional shape inspection apparatus 1 can be realized.

Further, the specific configuration of the image pickup unit 4, that is, the number and arrangement of the cameras 41 or the projectors 42, may vary.

Further, the imaging unit 4 is not limited to imaging the object J on which the pattern is projected. Therefore, the imaging unit 4 is configured so as to capture a distance image of the object J based on the result of detecting the laser beam reflected by the object J with the solid-state imaging device while irradiating the object J with the laser beam. can be

INDUSTRIAL APPLICABILITY The present invention is applicable to all techniques for measuring the three-dimensional shape of an object.

DESCRIPTION OF SYMBOLS 1... Three-dimensional shape inspection apparatus 4... Imaging unit 9... Controller (computer)
912 ... difference calculation section 913 ... quality determination section 94 ... imaging control section (data acquisition section)
Dm...Measurement data Dr...Good product data L...Reference plane Pi...Inspection program (three-dimensional shape inspection program)
Rf... Flat area (target area)
Rp1, Rp2...Candidate area Rw...Wall area Sm, Sr...Three-dimensional shape Z...Z-axis direction (predetermined direction)

Claims (9)

an imaging unit that images an object;
a data acquisition unit that acquires measurement data by measuring the three-dimensional shape of the surface of the object based on the result of causing the imaging unit to image the object;
By comparing the measurement data with non-defective product data indicating the three-dimensional shape of the surface of a non-defective product, the position of the surface of the object indicated by the measurement data and the non-defective product indicated by the non-defective product data are compared. a difference calculation unit for obtaining a difference in a predetermined direction from the position of the surface of the
Based on the difference in the surface of the non-defective product indicated by the non-defective product data, the shape of the object is determined based on the difference in the target region excluding a wall surface region having an acute angle with respect to the predetermined direction smaller than a predetermined angle or parallel to the predetermined direction. A quality determination unit that determines the presence or absence of defects ,
The difference calculation unit performs data matching for executing alignment between the three-dimensional shape indicated by the non-defective product data and the three-dimensional shape indicated by the measurement data, and then the wall region and the wall region in the three-dimensional shape indicated by the non-defective product data. A three-dimensional shape inspection apparatus that sets a mask on the wall surface region in the three-dimensional shape indicated by the measurement data, extracts the target region, and obtains the difference in the target region . The three-dimensional shape inspection apparatus according to claim 1, wherein the difference calculation unit does not calculate the difference for the wall surface area, but calculates the difference for the target area. 3. The three-dimensional structure according to claim 1, wherein the pass/fail determination unit excludes, from among the target regions, a region in which the magnitude of the difference in the predetermined direction is less than a predetermined value from the determination target of the presence or absence of the shape defect. Shape inspection device. 4. The pass/fail determination unit according to claim 3, wherein, of the regions remaining as the determination target in the target region, a region whose area on a plane perpendicular to the predetermined direction is less than a predetermined area is further excluded from the determination target. Three-dimensional shape inspection device. The pass/fail determination unit extracts a region remaining as the determination target from the target region as a candidate region, approximates a peripheral region of the candidate region with a plane orthogonal to the predetermined direction, and sets a reference plane. and determining that the shape defect exists in the candidate area when a distance from the reference plane at a position where the candidate area is farthest from the reference plane in the predetermined direction is equal to or greater than a threshold value. The three-dimensional shape inspection device described. 6. The three-dimensional shape inspection apparatus according to claim 5, wherein the pass/fail determination unit sets different threshold values for each of a plurality of ranges included in the target region. By comparing measurement data, which is the result of measuring the three-dimensional shape of the surface of the object, with non-defective product data showing the three-dimensional shape of the surface of a non-defective product, the object indicated by the measurement data is compared. A step of obtaining a difference in a predetermined direction between the surface position of the non-defective product and the surface position of the non-defective product indicated by the non-defective product data;
Based on the difference in the surface of the non-defective product indicated by the non-defective product data, the shape of the object is determined based on the difference in the target region excluding a wall surface region having an acute angle with respect to the predetermined direction smaller than a predetermined angle or parallel to the predetermined direction. and determining the presence or absence of defects ,
In the step of obtaining the difference, after performing data matching for executing alignment between the three-dimensional shape indicated by the non-defective product data and the three-dimensional shape indicated by the measurement data, the wall region in the three-dimensional shape indicated by the non-defective product data and a three-dimensional shape inspection method of extracting the target region by setting a mask on the wall surface region in the three-dimensional shape indicated by the measurement data, and obtaining the difference in the target region . By comparing measurement data, which is the result of measuring the three-dimensional shape of the surface of the object, with non-defective product data showing the three-dimensional shape of the surface of a non-defective product, the object indicated by the measurement data is compared. and a step of obtaining a difference in a predetermined direction between the surface position of the non-defective product and the surface position of the non-defective product indicated by the non-defective product data;
Based on the difference in the surface of the non-defective product indicated by the non-defective product data, the shape of the object is determined based on the difference in the target region excluding a wall surface region having an acute angle with respect to the predetermined direction smaller than a predetermined angle or parallel to the predetermined direction. causing a computer to execute a step of determining the presence or absence of defects ,
In the step of obtaining the difference, after performing data matching for executing alignment between the three-dimensional shape indicated by the non-defective product data and the three-dimensional shape indicated by the measurement data, the wall region in the three-dimensional shape indicated by the non-defective product data and a three-dimensional shape inspection program that causes the computer to execute a step of setting a mask on the wall surface region in the three-dimensional shape indicated by the measurement data, extracting the target region, and obtaining the difference in the target region . A computer that executes the three-dimensional shape inspection program according to claim 8.

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