WO2023238305A1

WO2023238305A1 - Clearance inspection method and clearance inspection device

Info

Publication number: WO2023238305A1
Application number: PCT/JP2022/023211
Authority: WO
Inventors: 典克鷲見
Original assignee: 日産自動車株式会社
Priority date: 2022-06-09
Filing date: 2022-06-09
Publication date: 2023-12-14

Abstract

In this clearance inspection method, first, a region which includes an ignition coil (3) and a fuel tube (4) is scanned to obtain measurement data including a portion of the outer surface of each of such components, and to obtain design data including the outer shape of each of the components and the positional relationship between the two components within an assembly. Further, in the clearance inspection method: the design data of the ignition coil (3) is aligned, as a rigid body, with the position of the measurement data of the ignition coil (3), and the outer shape of the ignition coil (3) including a hidden outer surface portion is generated; the design data of the fuel tube (4) is aligned, as a non-rigid body, with the position of the design data of the fuel tube (4); the outer shape of the fuel tube (4) including a hidden outer surface portion is generated; and the distance between the two components is calculated.

Description

Gap inspection method and gap inspection device

The present invention provides a gap inspection method and gap inspection for inspecting the distance between a first component and a second component in an assembly formed by assembling a plurality of components including a rigid first component and a non-rigid second component. Regarding equipment.

For example, in a completed automobile inspection process, a worker may measure the distance between two parts out of a plurality of parts arranged in an engine room using a ruler. In this completed vehicle inspection process, distances may be measured many times by moving the ruler to the back of the engine room while avoiding interference with other parts, which can make measurement difficult. Furthermore, there is a possibility that distance measurement may vary depending on the skill level of the operator.

Additionally, Patent Document 1 discloses a gap inspection method for measuring the spatial distance between a first rigid component and a second rigid component of an assembly. In this gap inspection method, the distance between the two parts is measured based on three-dimensional data that is the design data of the first part and three-dimensional data that is the design data of the second part.

However, in an assembly formed by assembling multiple parts, only rigid parts do not necessarily exist; when an assembly includes both rigid parts and non-rigid parts, rigid parts There is a need to measure the distance between an object and a non-rigid component.

The present invention was made with attention to such needs, and it is possible to calculate the distance between a first rigid part and a second non-rigid part in an assembly by scanning from the outside. A gap inspection method and a gap inspection device are provided.

JP 2017-10342 Publication

The present invention is a gap inspection method for inspecting the distance between a first part and a second part in an assembly formed by assembling a plurality of parts including a first rigid part and a second non-rigid part. , an area including the first part and the second part is scanned from the outside by a three-dimensional sensor to obtain measurement data including a part of the outer surface of each part, and the outer shape of each of the first part and the second part is determined. and the design data including the positional relationship within the assembly of both parts, and align the design data of the first part with the position of the measurement data of the first part as a rigid body, and Generate the outer shape of one part, align the design data of the second part with the position of the design data of the second part as a non-rigid body, and generate the outer shape of the second part including the hidden outer surface part. , calculate the distance between an arbitrary point on the first part and an arbitrary point on the second part.

According to the present invention, the distance between the first rigid part and the second non-rigid part in the assembly can be calculated by scanning from the outside.

FIG. 3 is an explanatory diagram of various parts in the engine compartment of one embodiment, viewed from above. FIG. 1 is a schematic diagram of a gap inspection device according to the present embodiment. This is point cloud data of the engine room and its internal parts scanned by a three-dimensional laser scanner. This is point cloud data of the engine room and its internal parts showing a progress of 40%. It is an explanatory diagram about reliability. FIG. 3 is an explanatory diagram showing an indication of the amount of displacement of the fuel tube on a display. It is a flowchart which shows the gap inspection method of a present Example.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In one embodiment, the present invention is applied to a gap inspection in which the spatial positions of two parts in an engine room are specified and the minimum gap between the two parts is calculated in a completed automobile inspection process.

FIG. 1 is a top view of some of the various parts in the engine room 1 of an automobile, which is an assembly of one embodiment, and shows the area near the intake manifold 2 of the engine. An ignition coil 3 that is part of the engine's ignition system is arranged below the intake manifold 2. Further, a fuel tube 4, which is a pipe for supplying fuel to the engine, is located on the side of the intake manifold 2. The fuel tube 4 is formed from a metal tube in consideration of oil resistance and fire resistance, and has a circular cross section along the radial direction. As shown in FIG. 1, the fuel tube 4 includes a straight portion 4a that extends generally linearly along the side of the intake manifold 2, and an inclined portion 4b that slopes toward the ignition coil 3 from one end of the straight portion 4a. have. The fuel tube 4 made of a metal tube undergoes some deformation during installation and is therefore considered a non-rigid component. On the other hand, the ignition coil 3 is a component that is considered to be a rigid body whose outer shape does not change. The minimum spatial distance (minimum gap) between the ignition coil 3 and the fuel tube 4 is prescribed by law, and therefore, it is necessary to inspect the minimum gap in the completed vehicle inspection process. Here, in many cases, the design minimum distance between the ignition coil 3 and the fuel tube 4 is defined at a position on the outer surface of at least one of the ignition coil 3 or the fuel tube 4 that is not visible from the outside, It is generally difficult for inspectors to measure using a ruler. In this embodiment, such a gap between two parts is determined by external measurement using a three-dimensional sensor and arithmetic processing.

In addition to the intake manifold 2, ignition coil 3, and fuel tube 4, a plurality of parts are provided within the engine room 1. In the completed vehicle inspection process of the present embodiment, the ignition is inspected in a vehicle that is assembled from a plurality of parts including the ignition coil 3, which is a rigid part, and the fuel tube 4, which is a non-rigid part that takes shape deformation into consideration. Check the distance between the coil 3 and the fuel tube 4.

As shown in FIG. 2, the gap inspection device of one embodiment used in the inspection process of finished automobiles includes a three-dimensional sensor, for example, a three-dimensional laser scanner 5, a database 6, a control device 7, and one or more components. It mainly consists of a display 8. In the finished vehicle inspection process, a large number of inspections are sequentially performed in a predetermined order. The gap inspection device of one embodiment is configured as a part of an inspection device in a completed vehicle inspection process.

The 3D laser scanner 5 can obtain the 3D coordinates of the surface shape of the measurement target by irradiating the measurement target with a laser beam and measuring the reflection time, and can scan at a high speed of approximately tens of thousands of points per second. By performing measurements with , high-density point cloud data can be obtained. Various sizes and types of three-dimensional laser scanners are known, but in one embodiment, a type that can be held in the hand by an operator to scan a measurement target is used. The target area is measured by manually scanning an area including the ignition coil 3 and fuel tube 4 along with other parts from the outside. By scanning with the three-dimensional laser scanner 5, as shown in FIG. 3, point cloud data of the entire area including a part of the outer surface of the ignition coil 3 and the fuel tube 4 is obtained.
Note that the point cloud data is actually acquired as time series data for each frame by scanning, but by overlapping the points, the point cloud data of the entire area is acquired. Furthermore, it is desirable to perform a noise removal process on the acquired point cloud data to remove noise caused by, for example, dust particles that have entered during scanning. Furthermore, the three-dimensional laser scanner may require a marker that serves as a guide for recognizing the shape and position of a target part during scanning.

Here, "scanning" in the present invention refers to either the surface scanning function of the three-dimensional sensor (for example, the three-dimensional laser scanner 5) itself, or the movement of the three-dimensional sensor performed by, for example, an operator. It is a concept that includes both. In one embodiment, a three-dimensional laser scanner 5 having a surface scanning function is used, and scanning is performed by moving the three-dimensional laser scanner 5. Depending on the size and shape of the target area to be measured or the type of 3D sensor, for example, multiple 3D sensors may be fixedly placed at appropriate positions in space and the scanning function of each 3D sensor may be used to measure the target area. It is also possible to obtain point cloud data of the area.

The database 6 stores all the design data of the vehicle to be inspected. Therefore, the shape data of the ignition coil 3 and the shape data of the fuel tube 4, which are the targets of the gap inspection, are the same between the two. It is stored as design data together with data indicating positional relationships in space. Furthermore, the database 6 also stores shape data and positional relationship data of other parts existing within the area. The design data is stored in the database 6 in the form of CAD data that constitutes a mesh. During the gap inspection, necessary design data is read from the database 6 to the control device 7. In addition, after reading the design data to the control device 7, well-known hidden surface processing is applied to parts other than those related to the gap between the ignition coil 3 and the fuel tube 4 to reduce the data size. You can also do it.

The control device 7 first aligns the design data of the ignition coil 3 as a rigid body to the position of the measurement data of the ignition coil 3 to generate the outer shape of the ignition coil 3 including the hidden outer surface portion, and further, The design data of the fuel tube 4 is aligned with the position of the measurement data of the fuel tube 4 as a non-rigid body, and various processes are executed to generate the outer shape of the fuel tube 4 including the hidden outer surface portion. Then, the control device 7 calculates the distance between an arbitrary point on the ignition coil 3 and an arbitrary point on the fuel tube 4 based on the generated outer shapes of the ignition coil 3 and the fuel tube 4. Each component of the control device 7 will be explained in detail later.

The display 8 displays the amount of displacement (movement) required for the fuel tube 4 and its location when the minimum distance calculated by the control device 7 is less than a threshold defined by law.

From now on, each component of the control device 7 will be explained. As shown in FIG. 2, the control device 7 includes a first alignment section 7a, a progress calculation section 7b, a second alignment section (rigid body alignment section) 7c, and a third alignment section (non-rigid body positioning section). It has a matching section) 7d, a reliability calculation section 7e, a first interpolation section 7f, a second interpolation section 7g, a distance calculation section 7h, and a displacement calculation section 7i.

The first alignment unit 7a is configured to match the entire target area (the so-called target area in alignment) including the ignition coil 3, fuel tube 4, and other parts in the measurement data acquired by the three-dimensional laser scanner 5, and the database 6. Rough alignment is performed with the entire area including the ignition coil 3, fuel tube 4, and other parts (area that serves as a so-called reference in alignment) in the accumulated design data. More specifically, the first alignment unit 7a uses the FPFH algorithm to search for a key point from the point cloud data of the entire target area, and determines the characteristics of this key point, such as the normal vector of the key point, etc. Describe the relative angles of the surroundings. Furthermore, the first alignment unit 7a converts the design data of the entire reference area into point cloud data using a well-known conversion method, and similarly searches for key points using the FPFH algorithm. The characteristics of this key point, such as the normal vector of the key point and the relative angles around it, are described. Then, the first alignment unit 7a compares the normal vectors between the target-related key points and the reference-related key points and the relative angles with the surrounding point group, so that the normal vectors and relative angles almost match. Then, the reference point cloud data is roughly aligned with the target point cloud data using the combination of key points forming the pair. Note that during this rough positioning, the fuel tube 4, which is a non-rigid body, is regarded as a rigid body, and as a result, for example, average positioning is performed within the length range of the fuel tube 4. Rough positioning of the target area by the first positioning unit 7a is performed in parallel with the progress of scanning of the target area. The first positioning unit 7a may perform rough positioning of the target area using a known algorithm other than the FPFH algorithm.

After the rough positioning by the first positioning unit 7a, the progress calculation unit 7b calculates necessary scanning within the target area before performing detailed positioning of the ignition coil 3 and fuel tube 4, which will be described later. Calculate the degree of progress that indicates how much progress has been made. In other words, the progress calculation unit 7b calculates the number of points of the point cloud data of the target area based on the design data serving as a reference, and the number of points that are matched with each other between the reference and the target through rough alignment by the first alignment unit 7a. The scanning progress is calculated from the ratio of . The progress calculation unit 7b further compares the progress calculated in this way with a predetermined progress threshold (for example, 40% in this embodiment), and calculates the progress that gradually increases as the scanning progresses. It is determined in real time whether this progress level threshold has been exceeded. For example, information on the progress level at that time and whether or not this progress level exceeds the progress level threshold is displayed on the display 8 via an information output unit (not shown). Scanning by the laser scanner 5 will continue. In other words, scanning (generation of point cloud data) by the three-dimensional laser scanner 5, rough alignment, and progress calculation are repeated in real time until a predetermined progress threshold is exceeded. For example, the area surrounded by a broken line in FIG. 4 corresponds to a progress level of 40%.

The degree of progress is evaluated not only by the ratio of the number of data points as described above, but also by the number of viewpoints passed by the three-dimensional laser scanner 5, the number of key points used in rough alignment, etc. Also good.

Since the basic shape or configuration of the area to be scanned is known as the design data obtained from the database 6, the basic shape or configuration of the area to be scanned is known as the design data obtained from the database 6. It is possible to estimate the movement trajectory including the position and the movement trajectory. Then, the degree of progress of scanning can be calculated based on how much distance scanned by the three-dimensional laser scanner 5 is included in the length of this movement trajectory.

Furthermore, regarding the viewpoint at the position of the 3D laser scanner 5, a plurality of representative viewpoints are predetermined, and how many representative viewpoints the 3D laser scanner 5 passes before drawing a movement trajectory? Based on this, the scanning progress can be determined.

Furthermore, the maximum number of keypoints is determined based on the point cloud data converted from the design data, so for this maximum number of keypoints, the point cloud data converted from the measurement data By determining the proportion of key points based on , the scanning progress can be calculated.

The second positioning unit 7c performs detailed positioning of each component in space on the condition that the degree of progress exceeds 40%. That is, the second positioning unit 7c searches for a pair of points in the reference point cloud data for all points in the target point cloud data obtained by measuring the ignition coil 3 and the fuel tube 4, and compares the points with the reference point cloud data. precisely align the point cloud data to the target point cloud data. The fuel tube 4, which is a non-rigid body, is considered to be a rigid body here, and as a result, average positioning is achieved within the length range of the fuel tube 4. Detailed alignment in the second alignment section 7c can be performed using a known appropriate algorithm.

The third positioning section 7d performs so-called non-rigid positioning of a non-rigid component (in this embodiment, the fuel tube 4) in consideration of deformation after the detailed positioning performed by the second positioning section 7c. be. Here, an appropriate well-known algorithm can be used, but for example, the nearest neighbor pair is searched from the reference point cloud data and the target point cloud data, which have been aligned and assumed to be rigid bodies, and the two points of the pair are searched for. The rotation, expansion, and parallel translation parameters are determined as parameters that bring the values closer to each other. For example, the outer shape of the fuel tube 4 is down-sampled so that the outer surface is made up of a plurality of triangles having vertices and edges, and each down-sampled area, that is, a plurality of adjacent triangles, is Using the vertices that represent the point cloud (cluster) of each region that contains the cluster, we rotate, expand, and transform the cluster with the constraint that the edge length does not change (strictly speaking, the length change is minimum). Decompose into parallel translation parameters. The entire deformation of the fuel tube 4 is obtained as a set of deformations in cluster units. The third alignment unit 7d deforms the reference point group data about the fuel tube 4 and aligns it with the target point group data in space using a non-rigid alignment method that takes such deformation into consideration.

The reliability calculation unit 7e calculates the reliability of the alignment of each target component (that is, the ignition coil 3 and the fuel tube 4). In other words, the reliability calculation unit 7e calculates the reliability indicating how close the target point cloud data is to the aligned reference point cloud data for each of the ignition coil 3 and the fuel tube 4. do.

FIG. 5 is an explanatory diagram schematically showing point cloud data of the fuel tube 4 after alignment, in order to explain reliability. To simplify the explanation, it is assumed here that the circular outer surface in a certain cross section of the fuel tube 4 is formed by 13 point group data. The 13 point cloud data Dr arranged in a circle is reference point cloud data based on design data, and the 7 point cloud data Dt arranged in a semicircle is target point cloud data based on measurement data. be. For example, as a result of scanning by the three-dimensional laser scanner 5 only from the upper side of the figure, the lower half becomes an area that is not scanned (deficient area), and the point group data Dt of the target is arranged in a semicircular shape.

The reliability is expressed, for example, as a ratio between the number of points of the reference point group data Dr and the number of points of the target point group data Dt included within a radius L from each point of this reference point group data Dr. In the figure, the range of radius L from a large number of points in the reference point group data Dr is represented by an outer circle C1 and an inner circle C2, respectively indicated by broken lines. In the example of FIG. 5A, since the four target point group data Dt are included within the range R of the circles C1 and C2, the reliability is 4/13. Furthermore, in the example shown in FIG. 5(b), since there are two target point cloud data Dt included within the range R of circles C1 and C2, the reliability is 2/13. In the example shown in FIG. 5C, all points of the target, that is, seven point group data Dt, are included in the region R, and the reliability is 7/13. In this way, the reliability is influenced by both the alignment accuracy and the size or proportion of the missing area in the measurement data.

The first interpolation unit 7f interpolates the missing portions of the measurement data of the ignition coil 3, that is, the point group data of the target, which are not scanned, using the reference point group data. In other words, the outer surface portion of the back side (lower side) of the ignition coil 3 that is hidden from view from the upper side of the engine room 1 is interpolated with reference point cloud data to generate point cloud data that includes the hidden portion. . Then, the first interpolation unit 7f converts the generated point group data into mesh data constituting a surface using a well-known conversion method.

Similarly, the second interpolation unit 7g interpolates the missing portions of the measurement data of the fuel tube 4, that is, the point group data of the target, which are not scanned, using the reference point group data. In other words, the outer surface portion of the back side (lower side) of the fuel tube 4 that is hidden from view from the upper side of the engine room 1 is interpolated using the reference point cloud data, and the point cloud of the fuel tube 4 including the hidden portion is interpolated using the reference point cloud data. Generate data. Then, the second interpolation unit 7g converts the generated point group data into mesh data constituting a surface using a well-known conversion method.

The distance calculation unit 7h calculates each distance on the surface of the ignition coil 3 based on the mesh data of the ignition coil 3 acquired by the first interpolation unit 7f and the mesh data of the fuel tube 4 acquired by the second interpolation unit 7g. The distance from each point to each point on the surface of the fuel tube 4 is calculated. Further, the distance calculation unit 7h calculates the minimum distance by comparing the calculated distances with each other. Note that the distance calculation unit 7h does not convert the point cloud data of the ignition coil 3 and the point cloud data of the fuel tube 4 into mesh data, but based on each point cloud data, the distance calculation unit 7h calculates the distance from each point of the ignition coil 3 to the fuel tube. The distances to each of the four points may also be calculated. Further, the distance calculation unit 7h compares the minimum distance with a predetermined threshold value, and when the minimum distance is less than the threshold value, presents information on the display 8 that the minimum distance is less than the threshold value. In addition, when presenting information to the worker that the minimum distance is less than the threshold, in addition to the image presentation using the display described above, the information may be presented audibly using an audio device such as a speaker. However, information may be presented by vibration using a wearable device such as a scanner held in the worker's hand or a watch worn by the worker. In the case of information presentation using vibration, whether the information is above a threshold value or below a threshold value may be presented based on a predetermined vibration pattern.

When the minimum distance is less than a predetermined threshold, the displacement calculation unit 7i calculates the amount of movement necessary for the fuel tube 4 for the minimum distance and some representative points, that is, in order for the minimum distance to be equal to or greater than the threshold. The required amount of displacement of the fuel tube 4 is quantitatively calculated and the information is presented on the display 8.

The display 8 displays the amount of displacement required for the fuel tube 4 as well as the minimum distance between the ignition coil 3 and the fuel tube 4 and its location. The display 8 also shows the desired arrangement of the fuel tubes 4 in the engine room 1 by the area between the two curves W1 and W2 shown by broken lines in FIG. If it is less than the threshold, the fuel tube 4 is displaced based on the displacement amount (not shown) displayed on the display 8, so that the fuel tube 4 is placed in the area between the curves W1 and W2. Further, a dark colored portion adjacent to the side of the fuel tube 4 indicates a portion of the fuel tube 4 before the operator displaces the fuel tube 4. In this embodiment, as shown in FIG. 6, the displacement calculation unit 7i calculates a distance of 20 mm in a direction P away from the intake manifold 2 with respect to a point of a straight portion 4a that extends linearly along the side of the intake manifold 2. Furthermore, the displacement amount of 10 mm along another direction Q away from the intake manifold 2 is displayed for one point of the inclined portion 4b inclined toward the ignition coil 3 (see FIG. 1). In addition, in FIG. 6, illustration of the minimum distance and the location of the minimum distance is omitted, but the location of the minimum distance is diagonally lower left of the location of the inclined portion 4b where the displacement amount is applied in the direction Q. and the ignition coil 3 (see FIG. 1).

Next, the gap inspection method of this embodiment will be explained based on the flowchart of FIG.

First, in step S1, a predetermined area in the engine room 1 including the target parts ignition coil 3 and fuel tube 4 is scanned from the outside by an operator operating the three-dimensional laser scanner 5. Obtain point cloud data that includes part of the surface. This scanning and generation of point cloud data progresses gradually along with the scanning operation.

Next, in step S2, CAD data of the target parts, such as the ignition coil 3, fuel tube 4, and other surrounding parts, is acquired from the database 6, along with CAD data indicating their spatial positional relationships.

Then, in step S3, the CAD data is converted to point cloud data using a known appropriate conversion method.

Next, in step S4, the first alignment unit 7a performs rough alignment between the entire target area and the entire reference area. As mentioned above, point cloud data of the entire area including the ignition coil 3, fuel tube 4, and other parts, and point cloud data of the entire area including the ignition coil, fuel tube, and other parts in the design data stored in the database 6. Rough alignment is performed by searching for key points and aligning by using combinations of paired key points.

After the rough alignment in step S4, in step S5, the progress calculation unit 7b calculates the points of the point cloud data of the reference area and the matched points in the point cloud data of the scanned area. The scanning progress is calculated from the ratio of .

Then, in step S6, it is determined whether this progress exceeds a predetermined progress threshold (40% in this embodiment, but the threshold is not limited to this). If the degree of progress is 40% or less, the process moves to step S7, the degree of progress is displayed on the display 8, and the worker continues scanning. In other words, the processing from step S1 onwards is repeated.

In addition, if the progress exceeds 40% in step S6, the process moves to step S8, and the ignition coil 3 and fuel tube 4, which are the target parts, are extracted from the point cloud data of the measurement data and the point cloud data of the design data. Extract each. Point cloud data extracted from measurement data becomes a so-called target, and point cloud data extracted from design data becomes a so-called reference. The point cloud data of the target part serving as a reference may be generated from CAD data of a single part.

Next, in step S9, the second positioning section 7c performs detailed positioning of the ignition coil 3 and fuel tube 4 using a known appropriate algorithm. Here, the fuel tube 4 is considered to be a rigid body. For example, as described above, search for paired points between the target point cloud data that has undergone rough alignment and the reference point cloud data, and perform detailed alignment so that the reference approaches the target. .

Next, the third positioning unit 7d described above down-samples the data of the fuel tube 4 in step S10 in order to perform non-rigid positioning of the fuel tube 4, which is a non-rigid body. Then, in step S11, non-rigid positioning is performed in consideration of the deformation of the fuel tube 4. In other words, the reference point group data is aligned to the target position while being transformed. In this non-rigid alignment, the nearest pair is searched from the reference point cloud data and the target point cloud data, which are aligned as rigid bodies as described above, and rotation, enlargement, and translation are used as parameters to bring them closer to each other. seek.

Next, the process proceeds to step S12, and the reliability of alignment is calculated for each of the ignition coil 3 and the fuel tube 4. The reliability is expressed, for example, as a ratio between the number of points in the reference point group data and the number of points in the target point group data included within a predetermined radius from each point in the reference point group data.

Then, in step S13, it is determined whether the reliability of the ignition coil 3 and the reliability of the fuel tube 4 each satisfy a predetermined reliability. If both reliability levels satisfy the predetermined reliability level, it is assumed that the alignment has been completed, and the process moves to step S14.

In step S14, the first interpolation section 7f and the second interpolation section 7g interpolate the unscanned portion of the target point cloud data of the ignition coil 3 and fuel tube 4 with the reference point cloud data aligned with the target. do. As a result, point cloud data of the ignition coil 3 and the fuel tube 4 including unscanned portions (that is, hidden portions) is generated at each target position.

Then, in step S15, using a well-known conversion method, the point cloud data including the unscanned portions of both the ignition coil 3 and the fuel tube 4 are converted into mesh data forming a surface.

Next, in step S16, the distance calculation unit 7h calculates the minimum distance between the ignition coil 3 and the fuel tube 4 based on the mesh data of the ignition coil 3 and the mesh data of the fuel tube 4. That is, the distance between any two points on each surface is determined, and the minimum value therebetween is determined as the minimum distance.

Then, in step S17, it is determined whether the minimum distance is greater than or equal to a threshold value. If the minimum distance is greater than or equal to the threshold, the process moves to step S18, and information is presented on the display 8 that the minimum distance is greater than or equal to the threshold.

Further, if the minimum threshold value is less than the threshold value in step S17, the process moves to step S19, and the displacement amount calculation unit 7i calculates the displacement amount of the fuel tube 4 necessary for the minimum distance to be equal to or greater than the threshold value. The calculated displacement amount is displayed on the display 8.

Furthermore, if the reliability is less than the predetermined reliability in step S13, the process moves to step S20, and it is determined whether or not the scanned data is insufficient. If there is insufficient data, the process moves to step S21, where the operator is informed that scanning needs to be performed again using the three-dimensional laser scanner 5, and the process returns to step S1.

If it is determined in step S20 that the data is not insufficient, it is determined that the reliability in step S13 is low because the fuel tube 4 is excessively deformed, and the process proceeds to step S18. , a message to that effect is displayed on the display 8.

As described above, in this embodiment, the first interpolation unit 7f interpolates the outer surface portion hidden behind the rigid ignition coil 3 using reference point cloud data after positioning, and extracts the hidden portion. Generate point cloud data including the following to obtain the external shape. Similarly, after positioning, the second interpolation unit 7g interpolates the outer surface portion hidden on the back side of the non-rigid fuel tube 4 using the reference point cloud data, and extracts the point cloud data including the hidden portion. Generate and obtain the external shape. For the fuel tube 4, which is a non-rigid body that takes deformation into account, it is difficult to grasp the outer surface shape of the back side, and it is difficult to interpolate it by simply applying design data. By generating point cloud data including the hidden parts of 4 and obtaining the outer shape, and using it together with the outer shape of the ignition coil 3, it is possible to connect any point on the ignition coil 3 to any point on the fuel tube 4. The distance between can be easily calculated.

Furthermore, in this embodiment, the distance calculation unit 7h calculates the minimum distance between the ignition coil 3 and the fuel tube 4. Then, the distance calculation unit 7h compares the minimum distance with a threshold value, and when the minimum distance is less than the threshold value, presents information on the display 8 indicating that the minimum distance is less than the threshold value. Furthermore, when the minimum distance is less than the threshold value, the displacement calculation unit 7i quantitatively calculates the location where the minimum distance is and the amount of displacement of the fuel tube 4 necessary for the minimum distance to be equal to or greater than the threshold value, and displays the result. 8. Present information. Thereby, the operator can accurately displace the fuel tube 4 toward a desired position while looking at the fuel tube 4 displayed on the display 8 when the minimum distance is less than the threshold value. Further, since information is presented by voice or vibration that the minimum distance is less than the threshold, the worker can recognize that the minimum distance is less than the threshold while continuing the work without looking away.

In addition, in this embodiment, the point cloud data generated from the design data of the area including the ignition coil 3 and the fuel tube 4 is added to the point cloud data of the area acquired by scanning as measurement data, and the rough position is determined using key points. After alignment, the point cloud data of the ignition coil 3 based on the design data is aligned with the point cloud data of the ignition coil 3 extracted from the measurement data, and furthermore, the point cloud data of the fuel tube 4 based on the design data is aligned with the point cloud data of the ignition coil 3 extracted from the measurement data. It is aligned with the point group data of the fuel tube 4 extracted from the measurement data as a rigid body. In other words, the ignition coil 3 and the fuel tube 4 are roughly aligned, and after the positional relationship between the two is obtained in the scanned area, detailed alignment is performed individually. Therefore, the distance, that is, the gap can be calculated with high accuracy based on the positional relationship between the ignition coil 3 and the fuel tube 4.

Further, in this embodiment, the minimum distance between the ignition coil 3 and the fuel tube 4 is inspected in the completed automobile inspection process. In the inspection of a completed automobile, the ignition coil 3 and fuel tube 4 are already assembled together with various parts such as the intake manifold 2, and the ignition coil 3 is placed on the back side of the intake manifold 2 when viewed from the top of the engine room 1. It is located in a location that is difficult to measure. Furthermore, since the fuel tube 4 is a non-rigid body that undergoes deformation, it is difficult to measure compared to a rigid body. Therefore, by using the gap inspection method of this embodiment, the minimum distance between the ignition coil 3 and fuel tube 4, which are difficult to measure, can be efficiently inspected in the completed vehicle inspection process. The time required for the inspection process of a completed automobile can be shortened compared to the case of inspection using a vehicle.

Furthermore, in this embodiment, even if the minimum design distance between the ignition coil 3 and the fuel tube 4 is defined at a position on the outer surface of at least one of the ignition coil 3 and the fuel tube 4 that is not visible from the outside, good. Even in cases where such invisible outer surfaces of the ignition coil 3 and fuel tube 4 are included, the invisible outer surfaces can be detected using the first interpolation section 7f and the second interpolation section 7g of the gap inspection device of this embodiment. By interpolating , the minimum distance between the ignition coil 3 and the fuel tube 4 can be calculated.

In this embodiment, an example is disclosed in which the distance between the rigid ignition coil 3 and the non-rigid fuel tube 4 is calculated. The distance between the parts and the parts may be calculated.

Further, in this embodiment, an example of non-rigid positioning of the fuel tube 4 having a circular radial cross section has been described, but the present invention can also be applied to non-rigid positioning of a pipe having a radial cross section other than circular, for example, rectangular. May be applied.

In addition, in this embodiment, an example of calculating the distance between a rigid body part and a non-rigid body part of an automobile is disclosed, but the distance between a rigid body part and a non-rigid body part used for a vehicle other than an automobile is calculated. You can also calculate it.

Further, in the above embodiment, an example was explained in which the three-dimensional laser scanner 5 is held and operated by a worker, but the present invention can also be applied to a case where scanning is performed by a three-dimensional sensor by a robot.

Further, in this embodiment, the 3D laser scanner 5 has been described as a 3D sensor, but other types of 3D sensors, such as ToF type and triangulation type ones such as stereo cameras, can be widely applied. I can do it.

Claims

A gap inspection method for inspecting the distance between the first part and the second part in an assembly formed by assembling a plurality of parts including a first part of a rigid body and a second part of a non-rigid body, the method comprising:
scanning a region including the first part and the second part from the outside with a three-dimensional sensor to obtain measurement data including a part of the outer surface of each part;
obtaining design data including the external shapes of each of the first part and the second part and the positional relationship of both parts within the assembly;
generating an outer shape of the first part including a hidden outer surface portion by aligning the design data of the first part as a rigid body to the position of the measurement data of the first part;
aligning the design data of the second part as a non-rigid body to the position of the measurement data of the second part to generate an outer shape of the second part including a hidden outer surface portion;
calculating a distance between an arbitrary point on the first part and an arbitrary point on the second part;
Gap inspection method.
The gap inspection method according to claim 1, further comprising calculating a minimum distance between the first component and the second component.
The gap inspection method according to claim 2, further comprising: comparing the minimum distance with a threshold value, and presenting information indicating that the minimum distance is less than the threshold value when the minimum distance is less than the threshold value.
Further, when the minimum distance is less than the threshold, calculating the location of the minimum distance and the amount of displacement of the second component necessary for the minimum distance to be equal to or greater than the threshold, and presenting the information. The gap inspection method according to claim 3, comprising:
4. The gap inspection method according to claim 3, further comprising presenting the information by one or more of images, sounds, and vibrations when presenting the information that it is less than the threshold.
After roughly aligning the point cloud data of the area obtained by scanning as measurement data with the point cloud data generated from the design data of the area including the first part and the second part using key points,
The point cloud data of the first part based on the design data is aligned with the point cloud data of the first part extracted from the measurement data, and the point cloud data of the second part based on the design data is measured as a non-rigid body. The gap inspection method according to claim 1, wherein the gap inspection method is aligned with point cloud data of the second component extracted from .
The assembly is an automobile, the second part is a pipe arranged in an engine room, and the first part is a part in the engine room with a defined minimum distance from the pipe. The gap inspection method described in item 1.
The gap inspection method according to claim 1, wherein the minimum distance between the first part and the second part is inspected in a completed automobile inspection.
Claim 1: The minimum design distance between the first component and the second component is defined by a position on an outer surface of at least one of the first component and the second component that is not visible from the outside. Gap inspection method described in.
A gap inspection device for inspecting the distance between the first part and the second part in an assembly formed by assembling a plurality of parts including a first part of a rigid body and a second part of a non-rigid body,
a three-dimensional sensor that scans an area including the first part and the second part from the outside to obtain measurement data including a part of the outer surface of each part;
a database that stores design data including the external shapes of each of the first part and the second part and the positional relationship of both parts in the assembly;
a rigid body positioning unit that aligns the design data of the first part as a rigid body to the position of the measurement data of the first part;
a first interpolation unit that interpolates a hidden outer surface portion of the first component based on design data of the first component and generates an outer shape of the first component including the hidden outer surface portion;
a non-rigid positioning unit that positions the design data of the second part as a non-rigid body to the position of the design data of the second part;
a second interpolation unit that interpolates a hidden outer surface part of the second part based on design data of the second part and generates an outer shape of the second part including the hidden outer surface part;
a distance calculation unit that calculates a distance between an arbitrary point on the first part and an arbitrary point on the second part;
Gap inspection device equipped with.