JP6702710B2 - Inspection method of inspection object using geometric shape of automatically generated 3D scan data - Google Patents

Description

The present invention relates to an inspection method of an inspection object for determining whether an inspection object produced using CAD data has been accurately produced, and a geometric shape of automatically generated three-dimensional scan data. The present invention relates to a method for inspecting an inspection object using.

Generally, when operating a digital production system that utilizes CAD/CAM/CAE, three-dimensional scan data obtained by scanning the manufactured article after manufacturing the article using CAD data that is design data. And CAD data are compared to confirm that the manufactured goods are manufactured exactly as designed.

A method for inspecting an article manufactured by comparing such design data with CAD data is disclosed in, for example, Japanese Patent No. 10-0637727.

A conventional inspection method for CAD data and scan data, including the inspection method disclosed in the above-mentioned prior art, generally proceeds as follows.

First, input CAD data to the inspection system. Then, the article to be inspected is measured using the three-dimensional scanner, and the measured scan data is input to the inspection system. Then, the geometrical shape required for the inspection is generated from the CAD data. Then, a geometric shape corresponding to the geometric formation defined by the CAD data is generated in the scan data. Then, the coordinates of the CAD data and the scan data are matched. Then, an inspection element is generated with the above-mentioned geometrical shape, and the inspection elements are compared to create an inspection report.

In the conventional inspection method described above, the process of generating a geometric shape corresponding to the geometric shape defined by the CAD data in the scan data fundamentally affects the inspection result. Specifically, in order to generate a geometric shape in scan data, an operator manually selects a necessary portion from the scan data and then uses the data of the selected portion to generate the geometric shape.

However, in the above-described conventional inspection method, the process of generating the geometric shape in the scan data is manually performed by the operator, and therefore the operator selects the geometric shape corresponding to the same portion of the inspection object. Since the regions are different, the result of the generated geometric shape may be different, and the final inspection result may be different.

The present invention was invented to solve the above-mentioned problem, and the user does not need to arbitrarily select scan data corresponding to CAD data that is design data, and the inspection object is automatically generated. An object of the present invention is to provide a method for inspecting an object to be inspected, which uses the geometrical shape of automatically generated three-dimensional scan data so as not to change the final inspection result.

In order to achieve the above-mentioned object, the present invention provides a method for inspecting an inspection object by inputting a user command into a computing device and utilizing a geometric shape of automatically generated three-dimensional scan data. , A) inputting CAD data that is the design data of the inspection object, and b) acquiring 3D scan data showing the shape of the inspection object using a 3D scanner, and acquiring the acquired 3D scan data. Inputting, c) generating in the CAD data a geometric shape required for inspection, and d) automatically generating in the scan data a geometric shape corresponding to the geometric shape generated in the CAD data. And e) a step of aligning the CAD data and the scan data at the same coordinates, and f) generating an inspection element using the geometric shape generated in the CAD data and the scan data, and inspecting the CAD data and the scan data. And the step of: g) determining whether the inspection object is designed to match the design data based on the comparison result of the inspection elements, and generating a result report. It is characterized by

Preferably, the step d) includes i) extracting scan data corresponding to each surface of the CAD data, matching the CAD data with the scan data at a ratio of 1:1 and performing data filtering, and ii) the CAD data. Performing additional data filtering to obtain matched scan data, with the scan data being matched 1:1.

Here, in the step i), the step in which the deviation of the vertical elements of the CAD data and the scan data is more than the set value is filtered, and the deviation of the edge element of the CAD data and the scan data is more than the set value. Filtering things.

Preferably, the filtering step filters the scan data having a difference from the CAD data based on a predetermined criterion regarding size and density.

Further, in the step ii), the step of using only the CAD data corresponding to the set thickness region as a result is compared again with the vertical element of the CAD data and the scan data, and the deviation is equal to or more than the set value. It is characterized in that it includes a step of filtering again what is the above and a step of searching for an abnormal point from the scan data for which the filtering is completed.

Here, the step ii) further includes a step of excluding scan data corresponding to a boundary portion of the CAD data.

Preferably, the step of finding the abnormal point is characterized by using a method using mathematical statistics, a method of sampling by percentage, or a method of making all points approach a set distance.

According to the present invention, the final inspection result of the inspection object becomes the same by automatically generating the scan data corresponding to the CAD data, which is the design data, without the user having to arbitrarily select it. The repeatability of the process can be guaranteed.

Hereinafter, a preferred embodiment of an inspection method of an inspection object using a geometric shape of automatically generated three-dimensional scan data according to the present invention will be described in detail with reference to the accompanying drawings. For reference, in describing the present invention below, the terms that refer to the constituent elements of the present invention are named in consideration of the functions of the respective constituent elements, and are therefore meant to limit the technical constituent elements of the present invention. Should not be understood by.

FIG. 1 is a diagram showing a typical environment suitable for showing an embodiment of the present invention. Inspection of an inspection object using the geometric shape of automatically generated three-dimensional scan data according to the present invention. It is the block diagram which showed the structure of the inspection system for performing a method roughly.

The computing device 1 includes a processor for performing the inspection method according to the present invention. The computing device 1 is a workstation, a server, a laptop, a mainframe, a PDA, a cluster of devices working together, a virtual machine that can support such a processor. A virtual device, or other computing device.

The three-dimensional scanner 2 collects the scanned three-dimensional object, that is, high resolution points representing the shape of the inspection object, and acquires physical shape information of the inspection object. The three-dimensional scan data collected by the three-dimensional scanner 2 is primitive data and is a point cloud, a triangular mesh, a square mesh, a tetrahedral mesh, or a hexahedral mesh.

The user interface 3 enables the user 4 to input CAD data, which is design data, into the computing device, and the user input of the user interface 3 executes the process of performing the inspection method according to the present invention. The user interface 3 also includes options for selecting some tools for filtering the data and entering and setting parameters.

FIG. 2 is a flowchart showing a series of steps of an inspection method of an inspection object using a geometric shape of automatically generated three-dimensional scan data according to the present invention, and FIGS. It is the figure which schematized the processing process corresponding to the stage of.

A method of inspecting an inspection object using a geometric shape of automatically generated three-dimensional scan data according to the present invention is as follows, when a user inputs a user command to the computing device 1 using the user interface 3. This is a method of automatically generating the geometrical shape of the three-dimensional scan data and determining whether the inspection object is properly manufactured within the tolerance of the design data.

Specifically, the inspection method according to the present invention is performed through the following series of steps.

First, the CAD data, which is the design data of the inspection object, is input to the computing device 1 (S100). The user 4 can use the user interface 3 to input CAD data into the computing device 1. FIG. 3a shows the inspection object 5 displayed by the inputted CAD data.

Then, the three-dimensional scan data of the inspection object 5 is input to the computing device 1 (S200). The user 4 can use the three-dimensional scanner 2 to acquire three-dimensional scan data indicating the shape of the inspection object 5. Here, the three-dimensional scanner 2 communicates with the computing device 1, and the acquired three-dimensional scan data is provided to the computing device 1. FIG. 3b shows the inspection object 5 displayed by the input three-dimensional scan data.

When the input of the 3D scan data is completed, the user uses the option of the user interface 3 to generate the geometric shape required for the inspection in the CAD data (S300). At this stage, the user uses the options of the user interface 3 to set the criteria and to extract the geometric shapes according to the criteria. FIG. 3c is a diagram schematically showing how a geometric shape required for inspection is generated in CAD data. The user sets a reference plane by using the option of the user interface 3 and extracts one plane 5a. can do.

Subsequently, a geometric shape corresponding to the geometric shape generated in the CAD data is automatically generated in the three-dimensional scan data (S400). As described above, when the geometric shape of the CAD data is generated, the computing device 1 executes a built-in process to automatically generate the geometric shape corresponding to the geometric shape generated in the CAD data in three dimensions. Can be generated into scan data. FIG. 3d is a diagrammatic representation of a state in which a geometric shape 5b corresponding to the geometric shape of CAD data is generated from three-dimensional scan data.

Specifically, the step of S400 is performed in two steps of filtering data. First, scan data corresponding to each side of CAD data is extracted, CAD data and scan data are matched 1:1 and then the data is filtered (primary data filtering step). Then, with the CAD data and the scan data matched 1:1, the data is further filtered to obtain the matched scan data (secondary data filtering step).

The primary data filtering step includes a step of selecting a CAD data and a scan data having a large vertical difference. This step is a step of filtering data in which the deviation between the vertical elements of the CAD data and the scan data is equal to or larger than the set value. Further, the primary data filtering step further includes a step of selecting scan data corresponding to an edge of CAD data. At this stage, the scan data corresponding to the sharp edge of the CAD data is extracted, and the data where the deviation of the extracted data (the edge elements of the CAD data and the scan data) is greater than or equal to the set value is there.

Here, the filtering of vertical elements and edge elements in the primary data filtering stage is performed by comparing the CAD data with the size of the entire CAD data, the size of the entire scan data, and the defined standard regarding the density of the scan data. The difference is programmed to filter the scan data.

The secondary filtering stage performs the following stages to filter the data.

First, a thickness zone is given to the CAD data, and only the data coming into this area is used as a result. That is, only the CAD data corresponding to the preset thickness region is used as a result.

Then, the scan data corresponding to the boundary part of the CAD data is eliminated. For example, as shown in FIG. 4a, when generating a plane 5a from the top surface of CAD data, it is possible to use CAD data 5e having a boundary 6 as shown in FIG. 4b instead of one complete plane. Become. However, the scan data is likely to generate noise due to being connected to other elements at this boundary. In order to avoid such noise generation, as shown in FIG. 4c, the boundary portion 7 may be filtered so that data of a certain distance is not used in the boundary portion. Such a step may be performed by changing the option of the user interface when the user is not satisfied with the result value of the scan data. FIG. 4d is a schematic diagram showing a case where scan data is extracted without filtering the boundary portion 6.

After that, the vertical elements of the processed scan data and the vertical elements of the CAD data are compared again, and those whose deviation is equal to or greater than the set value are filtered again.

Then, filtering for finding out an abnormal point (outlier) from the scan data thus filtered is executed. Here, the step of searching for abnormal points in the data is to filter the abnormal points by using mathematical statistics (N*Sigma) or simply sample by percentage (%) to filter the abnormal points (Ratio). And, you can use any of the methods (Absolute Distance) to make all points close to the set distance. Such a method can be arbitrarily selected by the user using an option of the user interface. The scan data selected through the secondary filtering stage is then used as the final result of the subsequent process.

When the above-described secondary filtering step is completed, the computing device 1 executes a step (S500) of aligning the CAD data and the scan data with the reference coordinates according to the set process. At this time, the geometric shapes 5a and 5b generated in the steps of S300 and S400 described above can be used. The state where the CAD data 5c and the scan data 5d are aligned with the reference coordinates is shown in FIG. 3e.

Subsequently, the computing device 1 generates an inspection element using the geometric shape generated in the CAD data and the scan data, and executes a step (S600) of comparing the inspection element of the CAD data and the inspection element of the scan data. To do. Specifically, in the step of S600, the geometric shape generated in the step of S400 is used to generate inspection elements such as a straight line, a distance and a radius as shown in FIG. This is the stage of comparing the values of the scan data.

Finally, the computing device determines whether the inspection target 5 is designed to match the design data based on the comparison result of the inspection elements executed in step S600 described above, and reports the result of the determination. Is generated (S700).

As described above, in the inspection method of the inspection object using the geometrical shape of the automatically generated three-dimensional scan data according to the present invention, the user arbitrarily selects the scan data corresponding to the CAD data as the design data. Since it is not necessary and the final inspection result of the inspection object is made the same by automatically generating, the repeatability of the entire inspection process can be guaranteed.

The embodiments of the present invention described above merely exemplify the technical idea of the present invention, and the protection scope of the present invention should be construed according to the claims. Further, a person having ordinary knowledge in the technical field to which the present invention pertains can make various modifications and variations without departing from the essential characteristics of the present invention. All the technical ideas should be construed to be included in the scope of right of the present invention.
The inventions described in the initial claims of the present application will be additionally described below.
[1] A method of inspecting an inspection object by inputting a user command to a computing device and using a geometric shape of automatically generated three-dimensional scan data,
a) inputting CAD data which is design data of the inspection object,
b) acquiring three-dimensional scan data indicating the shape of the inspection object using the three-dimensional scanner and inputting the acquired three-dimensional scan data,
c) generating in the CAD data the geometry required for inspection,
d) automatically generating in the scan data a geometrical shape corresponding to the geometrical shape generated in the CAD data;
e) aligning the CAD data and the scan data at the same coordinates,
f) generating an inspection element using the geometric shape generated in the CAD data and the scan data, and comparing the inspection element of the CAD data with the inspection element of the scan data.
g) generating a result report by determining whether the inspection object is designed to match the design data based on the comparison result of the inspection elements, and automatically generating the inspection result. Method for inspecting an inspection object using the geometrical shape of the obtained three-dimensional scan data.
[2] The step d is
i) a step of extracting scan data corresponding to each side of the CAD data, matching the CAD data with the scan data at a ratio of 1:1 and performing data filtering,
ii) In the state where the CAD data and the scan data are matched 1:1, a step of performing additional data filtering in order to obtain the suitable scan data is included. A method for inspecting an inspection object using the geometrical shape of the three-dimensional scan data generated in the above.
[3] In the step i),
Filtering the deviation of the vertical direction elements of the CAD data and the scan data from a set value or more;
Utilizing the geometrical shape of the automatically generated three-dimensional scan data according to [2], characterized in that the CAD data and the step of filtering the deviation of the edge element of the scan data are equal to or more than a set value. Inspection method of the inspection object.
[4] The automatically generated according to [3], wherein the filtering step filters the scan data having a difference from the CAD data based on a predetermined criterion regarding size and density. A method of inspecting an inspection object using a geometrical shape of three-dimensional scan data.
[5] The step ii) includes
Using only CAD data corresponding to the set thickness region as a result,
Again comparing the vertical elements of the CAD data and the scan data and filtering again those whose deviation is greater than or equal to a set value;
The method of inspecting an inspection object using the geometrical shape of the automatically generated three-dimensional scan data according to [2], including a step of searching for abnormal points from the scan data that has been filtered.
[6] The step ii) includes
The method for inspecting an inspection object using the geometrical shape of the automatically generated three-dimensional scan data according to [5], further comprising a step of excluding scan data corresponding to a boundary portion of CAD data. .
[7] The step of finding the abnormal point is characterized by using a method using mathematical statistics, a method of sampling in percentage, or a method of making all points approach a set distance [5] or An inspection object inspection method using the geometrical shape of the automatically generated three-dimensional scan data according to [6].

FIG. 1 is a block diagram schematically showing a configuration of an inspection system for performing an inspection method of an inspection object using a geometric shape of automatically generated three-dimensional scan data according to the present invention. 3 is a flowchart showing a series of steps of an inspection method of an inspection object using a geometric shape of automatically generated three-dimensional scan data according to the present invention. 3 is a diagram illustrating a process corresponding to a series of steps in FIG. 2. 3 is a diagram illustrating a process corresponding to a series of steps in FIG. 2. 3 is a diagram illustrating a process corresponding to a series of steps in FIG. 2. 3 is a diagram illustrating a process corresponding to a series of steps in FIG. 2. 3 is a diagram illustrating a process corresponding to a series of steps in FIG. 2. 3 is a diagram illustrating a process corresponding to a series of steps in FIG. 2. 3 is a diagram illustrating a process of a secondary data filtering step. 3 is a diagram illustrating a process of a secondary data filtering step. 3 is a diagram illustrating a process of a secondary data filtering step. 3 is a diagram illustrating a process of a secondary data filtering step.

Claims (4)

A method of inputting a user command to a computing device and inspecting an inspection object using a geometric shape of automatically generated three-dimensional scan data,
a) inputting CAD data which is design data of the inspection object,
b) acquiring three-dimensional scan data indicating the shape of the inspection object using the three-dimensional scanner and inputting the acquired three-dimensional scan data,
c) generating in the CAD data the geometry required for inspection,
d) automatically generating, in the scan data, a geometric shape corresponding to the geometric shape generated in the CAD data;
e) aligning the CAD data and the scan data at the same coordinates,
f) generating an inspection element using the geometric shape generated in the CAD data and the scan data, and comparing the inspection element of the CAD data with the inspection element of the scan data.
g) determining whether the inspection object is designed to fit the design data based on the comparison result of the inspection elements, and generating a result report .
The d step is
i) a step of extracting scan data corresponding to each side of the CAD data, matching the CAD data with the scan data at a ratio of 1:1 and performing data filtering,
ii) performing additional data filtering to obtain suitable scan data in a state where the CAD data and the scan data are matched in a 1:1 manner,
The step i) includes
Filtering the deviations of the vertical direction elements of the CAD data and the scan data that are greater than or equal to a set value;
A step of filtering CAD data and a deviation of an edge element of the scan data which is equal to or more than a set value, and an object to be inspected using a geometric shape of the automatically generated three-dimensional scan data. Inspection method. The automatically generated three-dimensional scan according to claim 1 , wherein the filtering step filters the scan data having a difference from the CAD data based on a predetermined criterion of size and density. Inspection method of inspection object using geometrical shape of data. The step ii) includes
Using only CAD data corresponding to the set thickness region as a result,
Again comparing the vertical elements of the CAD data and the scan data and filtering again those whose deviation is greater than or equal to a set value;
The method for inspecting an inspection object using the geometrical shape of automatically generated three-dimensional scan data according to claim 1 , further comprising the step of searching for abnormal points from the scan data that has been filtered. 4. The automatic method according to claim 3 , wherein the step of searching for the abnormal point is performed by using a mathematical statistic, sampling by percentage, or making all points closer to a set distance. Method for inspecting an inspection object using the geometrical shape of three-dimensional scan data generated in a physical manner.