Gap inspection method and gap inspection device

Abstract

In a gap inspection method, first, measurement data including a portion of the outer surface of each member is acquired by scanning a region including an ignition coil (3) and a fuel pipe (4), and design data including the outer shape of each of the members and the positional relationship between the two members in an assembly is acquired. Next, in the gap inspection method, the design data of the ignition coil (3) is registered as a rigid body to the position of the measurement data of the ignition coil (3), an outer shape including the hidden outer surface portion of the ignition coil (3) is generated, the design data of the fuel pipe (4) is registered as a non-rigid body to the position of the design data of the fuel pipe (4), and the outer shape including the hidden outer surface portion of the ignition coil (3) is generated. And generating an outer shape of the fuel pipe (4) including the hidden outer surface portion, and calculating the distance between the two parts.

Description

Technical Field

[0001] The present invention relates to a gap inspection method and a gap inspection device for inspecting the distance between a first component and a second component in an assembly formed by assembling a plurality of components including a first component as a rigid body and a second component as a non-rigid body. Background Art

[0002] For example, in the whole vehicle inspection process of an automobile, an operator sometimes uses a ruler to measure the distance between two components among multiple components arranged in the engine compartment. In this whole vehicle inspection process, the distance measurement is sometimes performed multiple times while the ruler is moved to the deep side of the engine compartment to avoid interference with other components, so that the measurement sometimes becomes difficult. In addition, depending on the operator's proficiency, there may be deviations in the distance measurement.

[0003] In addition, a gap inspection method for measuring the spatial distance between a first component as a rigid body and a second component as a rigid body of an assembly is disclosed in Patent Document 1. In this gap inspection method, the distance between the two components is measured based on three-dimensional data as design data of the first component and three-dimensional data as design data of the second component.

[0004] However, in an assembly formed by assembling multiple parts, there are not necessarily only rigid parts. When the assembly includes both rigid parts and non-rigid parts, there is a need to measure the distance between the rigid parts and the non-rigid parts.

[0005] The present invention has been made in view of such a need, and provides a gap inspection method and a gap inspection device capable of calculating the distance between a first component as a rigid body and a second component as a non-rigid body in an assembly by scanning from the outside.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2017-10342 Summary of the invention

[0009] The present invention is a gap inspection method for inspecting the distance between a first component and a second component in an assembly formed by assembling a plurality of components including a first component as a rigid body and a second component as a non-rigid body. In the gap inspection method, a three-dimensional sensor is used to scan an area including the first component and the second component from the outside to obtain measurement data including a portion of the outer surface of each component, obtain design data including the outer shapes of each of the first component and the second component and the positional relationship between the first component and the second component in the assembly, align the design data of the first component as a rigid body to the position of the measurement data of the first component, and generate the outer shape of the first component including the hidden outer surface portion, align the design data of the second component as a non-rigid body to the position of the design data of the second component, and generate the outer shape of the second component including the hidden outer surface portion, and calculate the distance between any point of the first component and any point of the second component.

[0010] According to the present invention, the distance between the first member, which is a rigid body, and the second member, which is a non-rigid body, can be calculated in the assembly by scanning from the outside. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is an explanatory diagram of various components in an engine compartment according to an embodiment as viewed from above.

[0012] Figure 2 It is a schematic diagram of the gap inspection device of this embodiment.

[0013] Figure 3 It is the point cloud data of the engine compartment and its internal components obtained by scanning with a 3D laser scanner.

[0014] Figure 4 This is point cloud data of the engine compartment and its internal components, which shows 40% of the progress.

[0015] Figure 5 This is a diagram to illustrate reliability.

[0016] Figure 6 It is an explanatory diagram showing the indication of the displacement amount of the fuel pipe in the display.

[0017] Figure 7 : is a flowchart showing the gap inspection method of this embodiment. DETAILED DESCRIPTION

[0018] One embodiment of the present invention is described below with reference to the accompanying drawings. One embodiment is obtained by applying the present invention to a clearance inspection for determining the spatial positions of two components located in an engine compartment and calculating the minimum clearance between the two components in a vehicle inspection process.

[0019] Figure 1 This is a diagram of a portion of various components in an engine compartment 1 of an automobile as an assembly as viewed from above, showing an area near an intake manifold 2 of the engine. An ignition coil 3 as a part of the ignition device of the engine is arranged on the lower side of the intake manifold 2. In addition, a fuel pipe 4 as a pipe for supplying fuel to the engine is located on the side of the intake manifold 2. The fuel pipe 4 is formed of a metal pipe in consideration of oil resistance and fire resistance, and has a circular cross-section along the radial direction. Figure 1 As shown, the fuel pipe 4 has: a straight portion 4a, which extends roughly straight along the side of the intake manifold 2; and an inclined portion 4b, which is inclined from one end of the straight portion 4a to the ignition coil 3 side. The fuel pipe 4 composed of a metal pipe will produce some deformation during installation, and is therefore regarded as a non-rigid component. On the other hand, the ignition coil 3 is a component regarded as a rigid body whose outer shape does not change. The minimum distance (minimum gap) in space between the ignition coil 3 and the fuel pipe 4 is stipulated by law, so it is necessary to check the minimum gap in the whole vehicle inspection process. Here, in most cases, the designed minimum distance between the ignition coil 3 and the fuel pipe 4 is stipulated at the position of the outer surface of at least one of the ignition coil 3 and the fuel pipe 4 that cannot be visually confirmed from the outside, and it is generally difficult for the inspector to measure using a ruler. This embodiment obtains such a gap between the two components by measuring and calculating from the outside using a three-dimensional sensor.

[0020] In addition, a plurality of components are provided in the engine compartment 1 in addition to the intake manifold 2, the ignition coil 3, and the fuel pipe 4. In the vehicle inspection process of the present embodiment, the distance between the ignition coil 3 and the fuel pipe 4 is inspected in the vehicle assembled with a plurality of components including the ignition coil 3 as a rigid body and the fuel pipe 4 as a non-rigid body in consideration of shape deformation.

[0021] like Figure 2 As shown, a gap inspection device of an embodiment used in the whole vehicle inspection process of an automobile is mainly composed of a three-dimensional sensor such as a three-dimensional laser scanner 5, a database 6, a control device 7, and one or more displays 8. In addition, a large number of inspections are performed in a prescribed order in the whole vehicle inspection process. The gap inspection device of an embodiment is constituted as a part of the inspection device in the whole vehicle inspection process.

[0022] The 3D laser scanner 5 can obtain the 3D coordinates of the surface shape of the object being measured by irradiating the object with laser light and measuring the reflection time, and can obtain high-density point cloud data by measuring at a high speed of about tens of thousands of points per second. As 3D laser scanners, various sizes and forms of 3D laser scanners are known, but in one embodiment, a 3D laser scanner in a form that an operator can hold to scan the object being measured is used, and the area including the ignition coil 3, the fuel pipe 4, and other components is manually scanned from the outside to measure the object area. By scanning with such a 3D laser scanner 5, as shown in FIG. Figure 3 As shown, point cloud data of the entire region including a portion of the outer surface of the ignition coil 3 and the fuel pipe 4 is obtained.

[0023] In addition, the point cloud data is actually acquired as time series data for each frame by scanning, and the point cloud data of the entire region can be acquired by superposition. In addition, it is desirable to perform the following noise removal processing on the acquired point cloud data: for example, noise caused by dust entering during scanning is removed. In addition, as a three-dimensional laser scanner, a reference mark for identifying the shape and position of the target component during scanning may also be required.

[0024] Here, the "scanning" in the present invention is a concept that includes either or both of the plane scanning function of the three-dimensional sensor (e.g., the three-dimensional laser scanner 5) itself and the movement of the three-dimensional sensor by, for example, an operator. In one embodiment, scanning is performed by using a three-dimensional laser scanner 5 having a plane scanning function and moving the three-dimensional laser scanner 5. Depending on the size and shape of the object area to be measured or the form of the three-dimensional sensor, for example, multiple three-dimensional sensors can be fixedly arranged at appropriate positions in the space, and the scanning function of each three-dimensional sensor can be used to obtain point cloud data of the object area.

[0025] The database 6 stores all the design data of the automobile to be inspected, and therefore, the shape data of the ignition coil 3 and the shape data of the fuel pipe 4, which are the objects of the gap inspection, and the data indicating the positional relationship between the two in space are stored as design data. In addition, the database 6 also stores the shape data and positional relationship data of other components existing in the area. The design data is stored in the database 6 in the form of CAD data constituting a mesh. When inspecting the gap, the required design data is read from the database 6 to the control device 7. In addition, for the design data, after reading the control device 7, the well-known hidden surface processing can be performed on the parts other than the parts related to the gap between the ignition coil 3 and the fuel pipe 4 to reduce the data size.

[0026] The control device 7 first performs various processes to align the design data of the ignition coil 3 as a rigid body to the position of the measurement data of the ignition coil 3, and generate the outer shape of the ignition coil 3 including the hidden outer surface portion, and to align the design data of the fuel pipe 4 as a non-rigid body to the position of the measurement data of the fuel pipe 4, and generate the outer shape of the fuel pipe 4 including the hidden outer surface portion. Then, the control device 7 calculates the distance between an arbitrary point of the ignition coil 3 and an arbitrary point of the fuel pipe 4 based on the generated outer shapes of the ignition coil 3 and the fuel pipe 4. The components of the control device 7 are described in detail later.

[0027] When the minimum distance calculated by the control device 7 is smaller than a threshold value prescribed by laws and regulations, the display 8 displays the required displacement amount (movement amount) of the fuel pipe 4 and its location.

[0028] From now on, the components of the control device 7 will be described. Figure 2 As shown, the control device 7 has a first registration unit 7a, a progress calculation unit 7b, a second registration unit (rigid registration unit) 7c, a third registration unit (non-rigid registration unit) 7d, a reliability calculation unit 7e, a first filling unit 7f, a second filling unit 7g, a distance calculation unit 7h, and a displacement calculation unit 7i.

[0029] The first registration unit 7a performs a rough registration of the entire object area (the so-called target area in the registration) including the ignition coil 3, the fuel pipe 4 and other components in the measurement data acquired by the three-dimensional laser scanner 5 with the entire area (the so-called reference area in the registration) including the ignition coil 3, the fuel pipe 4 and other components in the design data accumulated in the database 6. More specifically, the first registration unit 7a uses the FPFH algorithm to search for key points from the point cloud data of the entire target area, and describes the characteristics of the key points, such as the normal vector of the key points and the relative angles around them. In addition, the first registration unit 7a uses the FPFH algorithm to search for key points on the basis of transforming the design data of the entire reference area into point cloud data using a well-known transformation method, and describes the characteristics of the key points, such as the normal vector of the key points and the relative angles around them. Then, the first registration unit 7a searches for a combination of key points whose normal vectors and relative angles are roughly consistent by comparing the normal vectors between the key points related to the target and the key points related to the reference, and the relative angles with the surrounding point clouds, and then uses the combination of paired key points to roughly align the reference point cloud data with the target point cloud data. In addition, during this rough registration, the fuel pipe 4, which is a non-rigid body, is regarded as a rigid body, and as a result, an average registration is performed within the length of the fuel pipe 4, for example. The rough registration of the object area performed by the first registration unit 7a is performed in parallel with the progress of the scanning of the object area. The first registration unit 7a can also use a known algorithm other than the FPFH algorithm to perform rough registration of the object area.

[0030] After the rough alignment performed by the first alignment unit 7a and before the detailed alignment of the ignition coil 3 and the fuel pipe 4 described later, the progress calculation unit 7b calculates the progress indicating how far the required scanning in the object area has progressed. That is, the progress calculation unit 7b calculates the progress of the scan based on the ratio of the number of points in the point cloud data of the object area based on the design data used as a reference to the number of points that match each other between the reference and the target through the rough alignment performed by the first alignment unit 7a. The progress calculation unit 7b further compares the progress calculated in this way with a prescribed progress threshold (for example, 40% in this embodiment) and determines in real time whether the progress that gradually increases with the progress of the scan exceeds the progress threshold. For example, the progress at this time and the information on whether the progress exceeds the progress threshold are displayed on the display 8 via the information output unit not shown, so the operator continues to scan using the three-dimensional laser scanner 5 according to the display. In other words, scanning (generation of point cloud data), rough alignment, and progress calculation using the three-dimensional laser scanner 5 are repeated in real time until the prescribed progress threshold is exceeded. For example, in Figure 4 The area enclosed by the dotted line corresponds to 40% of the progress.

[0031] In addition, the progress may be evaluated based on the number of viewpoints that the three-dimensional laser scanner 5 has passed, the number of key points used in rough registration, or the like, in addition to the evaluation based on the ratio of the number of data points as described above.

[0032] The basic shape or structure of the area to be scanned is known as design data obtained from the database 6, so it is possible to estimate the movement trajectory of the 3D laser scanner 5 in a manner including the position of the 3D laser scanner 5 in space and its movement trajectory based on the point cloud data successively obtained from the 3D laser scanner 5. Then, the progress of the scanning can be calculated based on the extent to which the distance scanned by the 3D laser scanner 5 is included in the length of the movement trajectory.

[0033] In addition, a plurality of representative viewpoints are predetermined regarding the viewpoints at the position of the three-dimensional laser scanner 5 , and the progress of scanning can be obtained based on how many representative viewpoints the three-dimensional laser scanner 5 has passed until drawing a movement trajectory.

[0034] Furthermore, the maximum number of key points is determined based on the point cloud data transformed from the design data. Therefore, the scanning progress can be calculated by calculating the ratio of the key points based on the point cloud data transformed from the measurement data to the maximum number of key points.

[0035] The second registration unit 7c performs detailed spatial registration of each component on the condition that the progress exceeds 40%. That is, the second registration unit 7c searches for paired points from the reference point cloud data for all points of the target point cloud data obtained by measuring the ignition coil 3 and the fuel pipe 4, and performs detailed registration of the reference point cloud data with the target point cloud data. The fuel pipe 4, which is a non-rigid body, is regarded as a rigid body here, and as a result, an average registration is performed within the length range of the fuel pipe 4. The detailed registration of the second registration unit 7c can be performed using a known appropriate algorithm.

[0036] After the detailed registration performed by the second registration unit 7c, the third registration unit 7d performs so-called non-rigid registration for the non-rigid component (the fuel pipe 4 in this embodiment) in consideration of deformation. Here, a known appropriate 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 that have been previously registered as a rigid body, and the parameters of rotation, enlargement, and translation are obtained as parameters that make the two points of the pair approach each other. For example, the outer shape of the fuel pipe 4 is downsampled to form a shape in which the outer surface is composed of a plurality of triangles having vertices and edges, and the vertices of the point cloud (cluster) representing each area obtained by downsampling, that is, each area including a plurality of adjacent triangles are used, and the constraint that the length of the edge does not change (strictly speaking, the length change is minimized) is added, and the deformation of the cluster is decomposed into the parameters of rotation, enlargement, and translation. The overall deformation of the fuel pipe 4 is obtained as a collection of such deformations in cluster units. The third registration unit 7 d deforms the reference point cloud data on the fuel pipe 4 by using such a non-rigid registration method taking deformation into consideration, and registers the data with the target point cloud data in space.

[0037] The reliability calculation unit 7e calculates the reliability of the registration for each target component (i.e., the ignition coil 3 and the fuel pipe 4). In other words, the reliability calculation unit 7e calculates the reliability of the point cloud data indicating how many targets are included in the vicinity of the reference point cloud data after registration for each of the ignition coil 3 and the fuel pipe 4.

[0038] Figure 5 This is an explanatory diagram schematically showing the point cloud data of the fuel pipe 4 after registration in order to illustrate the reliability. In order to simplify the explanation, it is assumed that the circular outer surface at a certain cross section of the fuel pipe 4 is formed by 13 point cloud data. The 13 point cloud data Dr arranged in a circle are reference point cloud data based on the design data, and the 7 point cloud data Dt arranged in a semicircle are target point cloud data based on the measurement data. For example, the three-dimensional laser scanner 5 is scanned only from the upper side of the figure, and as a result, the lower half becomes an unscanned area (missing area), and the target point cloud data Dt is arranged in a semicircle.

[0039] Reliability is represented, for example, by the ratio of the number of points of the reference point cloud data Dr to the number of points of the target point cloud data Dt included in the range of radius L from each point of the reference point cloud data Dr. In addition, in the figure, the range of radius L from a large number of points of the reference point cloud data Dr is represented by an outer circle C1 and an inner circle C2 represented by dotted lines, respectively. Figure 5 In the example (a), the four point cloud data Dt of the target are included in the range R of the circles C1 and C2, so the reliability is 4 / 13. Figure 5In the example shown in (b), there are two target point cloud data Dt included in the range R of circles C1 and C2, so the reliability is 2 / 13. Figure 5 In the example shown in (c), all the target points, that is, 7 point cloud data Dt are included in the region R, and the reliability is 7 / 13. As described above, the reliability is affected by both the accuracy of registration and the size or ratio of the missing area in the measurement data.

[0040] The first filling unit 7f fills in the missing part that is not scanned in the measurement data of the ignition coil 3, that is, the target point cloud data, using the reference point cloud data. In other words, the outer surface part of the back side (lower side) of the ignition coil 3 that is hidden and cannot be observed from the upper side of the engine compartment 1 is filled in with the reference point cloud data to generate point cloud data including the hidden part. Then, the first filling unit 7f transforms the generated point cloud data into mesh data constituting a surface using a well-known transformation method.

[0041] Similarly, the second filling unit 7g fills in the missing portion that is not scanned in the measurement data of the fuel pipe 4, that is, the target point cloud data, using the reference point cloud data. In other words, the outer surface portion of the back side (lower side) of the fuel pipe 4 that is hidden and cannot be observed from the upper side of the engine compartment 1 is filled in with the reference point cloud data to generate point cloud data including the hidden portion of the fuel pipe 4. Then, the second filling unit 7g transforms the generated point cloud data into mesh data constituting a surface using a well-known transformation method.

[0042] The distance calculation unit 7h calculates the distance from each point on the surface of the ignition coil 3 to each point on the surface of the fuel pipe 4 based on the mesh data of the ignition coil 3 obtained by the first filling unit 7f and the mesh data of the fuel pipe 4 obtained by the second filling unit 7g. And the distance calculation unit 7h finds the minimum distance by comparing the calculated distances. In addition, instead of converting the point cloud data of the ignition coil 3 and the point cloud data of the fuel pipe 4 into mesh data, the distance calculation unit 7h calculates the distance from each point of the ignition coil 3 to each point of the fuel pipe 4 based on each point cloud data. In addition, 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, the display 8 presents information that the minimum distance is less than the threshold value. In addition, when presenting information to the operator that the minimum distance is less than the threshold value, in addition to the image-based presentation using the aforementioned display, a speaker or other audio device may be used for sound presentation, and a scanner held in the hand of the operator or a wearable device such as a watch worn by the operator may be used for vibration presentation. When presenting information based on vibration, whether the value is above or below a threshold value may be presented using a predetermined vibration pattern.

[0043] When the minimum distance is less than a prescribed threshold, the displacement calculation unit 7i quantitatively calculates the required movement amount of the fuel pipe 4, that is, the displacement amount of the fuel pipe 4 required to make the minimum distance above the threshold, for the portion where the minimum distance occurs and several representative points, and displays the information on the display 8.

[0044] The display 8 displays the minimum distance between the ignition coil 3 and the fuel pipe 4 and the position thereof together with the required displacement of the fuel pipe 4. Figure 6 The area between the two curves W1 and W2 shown by dashed lines in the figure shows the desired arrangement of the fuel pipe 4 in the engine compartment 1. When the minimum distance is less than the threshold, the operator displaces the fuel pipe 4 based on the displacement amount (not shown) displayed on the display 8, thereby bringing the fuel pipe 4 into the area between the curves W1 and W2. In addition, the portion adjacent to the side of the fuel pipe 4 shown in dark color shows a portion of the fuel pipe 4 before the operator displaces the fuel pipe 4. In this embodiment, Figure 6 As shown, the displacement calculation unit 7i displays a displacement of 20 mm in a direction P away from the intake manifold 2 for a point on the straight portion 4a extending straightly along the side of the intake manifold 2, and displays a displacement of 20 mm ... in a direction P away from the intake manifold 2 for a point on the ignition coil 3 (see Figure 1 ) side, a location of the inclined portion 4b that is inclined shows a displacement of 10 mm in the other direction Q away from the intake manifold 2. Figure 6In the figure, the minimum distance and the position of the minimum distance are omitted, but the position of the minimum distance is located at the lower left side of the position to which the displacement amount is applied in the direction Q in the inclined portion 4b and is close to the ignition coil 3 (refer to Figure 1 )between.

[0045] Next, based on Figure 7 The gap checking method of this embodiment is described with reference to the flowchart of FIG.

[0046] First, in step S1, the operator operates the three-dimensional laser scanner 5 to scan a predetermined area including the ignition coil 3 and the fuel pipe 4 as target components in the engine compartment 1 from the outside, thereby acquiring point cloud data including a portion of the outer surface of each component. The scanning and generation of point cloud data gradually progresses along with the scanning operation.

[0047] Next, in step S2 , CAD data of the ignition coil 3 , the fuel pipe 4 , and other peripheral components as target components, and CAD data indicating the spatial positional relationship between them are acquired from the database 6 .

[0048] Then, in step S3, the CAD data is transformed into point cloud data using a known appropriate transformation method.

[0049] Next, in step S4, the first registration unit 7a performs a rough registration of the entire target region with the entire reference region. As described above, the point cloud data of the entire region including the ignition coil 3, the fuel pipe 4 and other components is registered with the point cloud data of the entire region including the ignition coil, the fuel pipe and other components in the design data accumulated in the database 6 by searching for key points and combining paired key points, thereby performing a rough registration.

[0050] After the rough registration in step S4, in step S5, the progress calculation unit 7b as described above calculates the progress of the scan based on the ratio between the number of points in the point cloud data of the reference area and the number of matching points in the point cloud data of the scanned area.

[0051] Then, in step S6, it is determined whether the progress exceeds a predetermined progress threshold (40% in this embodiment, but the threshold is not limited thereto). If the progress is below 40%, the process proceeds to step S7, where the progress is displayed on the display 8, and the operator continues scanning. That is, the process after step S1 is repeated.

[0052] In addition, if the progress exceeds 40% in step S6, the process proceeds to step S8, and the ignition coil 3 and the fuel pipe 4 as the target parts are extracted from the point cloud data of the measurement data and the point cloud data of the design data, respectively. The point cloud data extracted from the measurement data becomes the so-called target, and the point cloud data extracted from the design data becomes the so-called reference. The point cloud data of the target part as a reference can also be generated based on the CAD data of the component itself.

[0053] Next, in step S9, as the second registration unit 7c, a known appropriate algorithm is used to perform detailed registration of the ignition coil 3 and the fuel pipe 4. Here, the fuel pipe 4 is regarded as a rigid body. For example, as described above, a pair of points is searched between the point cloud data of the target that has undergone rough registration and the point cloud data of the reference, and detailed registration is performed in a manner that the reference and the target are close.

[0054] Next, the third registration unit 7d described above performs downsampling on the data of the fuel pipe 4 in step S10 to perform non-rigid registration of the fuel pipe 4 as a non-rigid body. Then, in step S11, non-rigid registration of the fuel pipe 4 is performed in consideration of deformation. That is, the reference point cloud data is deformed while being registered to the position of the target. In this non-rigid registration, the nearest neighbor pair is searched from the reference point cloud data and the target point cloud data registered as a rigid body as described above, and rotation, enlargement, and translation as mutually close parameters are obtained.

[0055] Next, the process proceeds to step S12 to calculate the reliability of the registration for the ignition coil 3 and the fuel pipe 4. The reliability is expressed, for example, by the ratio of the number of points in the reference point cloud data to the number of points in the target point cloud data within a predetermined radius from each point in the reference point cloud data.

[0056] Then, in step S13, it is determined whether the reliability of the ignition coil 3 and the reliability of the fuel pipe 4 satisfy the predetermined reliability. If both reliability satisfy the predetermined reliability, the registration is considered complete and the process proceeds to step S14.

[0057] In step S14, the first filling unit 7f and the second filling unit 7g fill in the unscanned parts of the point cloud data of the ignition coil 3 and the fuel pipe 4 with the reference point cloud data registered with the target. Thus, the point cloud data of the ignition coil 3 and the fuel pipe 4 including the unscanned parts (that is, the hidden parts) at the positions of the respective targets are generated.

[0058] Then, in step S15 , the point cloud data including the unscanned portions of both the ignition coil 3 and the fuel pipe 4 are converted into mesh data constituting a surface using a known conversion method.

[0059] Next, in step S16, the distance calculator 7h calculates the minimum distance between the ignition coil 3 and the fuel pipe 4 based on the mesh data of the ignition coil 3 and the mesh data of the fuel pipe 4. That is, the distance between any two points on each surface is obtained, and the minimum value is set as the minimum distance.

[0060] 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 value, the process proceeds to step S18, and information indicating that the minimum distance is greater than or equal to the threshold value is presented on the display 8.

[0061] If the minimum threshold is smaller than the threshold in step S17 , the process proceeds to step S19 , where the displacement amount calculation unit 7 i calculates the displacement amount of the fuel pipe 4 required to make the minimum distance equal to or greater than the threshold.

[0062] In addition, if the reliability is less than the specified reliability in step S13, the process proceeds to step S20 to determine whether the scanned data is insufficient. If the data is insufficient, the process proceeds to step S21 to inform the operator that another scan is required using the three-dimensional laser scanner 5, and the process returns to step S1.

[0063] If it is determined in step S20 that the data is not insufficient, it is assumed that the reliability in step S13 is determined to be low due to excessive deformation of the fuel pipe 4, and the process proceeds to step S18, whereby the display 8 displays this fact.

[0064] As described above, in this embodiment, as the first filling part 7f, after registration, the hidden outer surface portion of the back side of the ignition coil 3 as a rigid body is filled with the reference point cloud data, and the point cloud data including the hidden portion is generated to obtain the outer shape. Similarly, as the second filling part 7g, after registration, the hidden outer surface portion of the back side of the fuel pipe 4 as a non-rigid body is filled with the reference point cloud data, and the point cloud data including the hidden portion is generated to obtain the outer shape. With regard to the fuel pipe 4 as a non-rigid body, which is deformed, it is difficult to grasp the outer surface shape of the back side, and it is difficult to fill it by simply applying the design data. However, as in this embodiment, registration is performed to generate the point cloud data including the hidden portion of the fuel pipe 4 to obtain the outer shape, and it is used together with the outer shape of the ignition coil 3, thereby making it easy to calculate the distance between any point of the ignition coil 3 and any point of the fuel pipe 4.

[0065] In addition, in the present embodiment, the distance calculation unit 7h calculates the minimum distance between the ignition coil 3 and the fuel pipe 4. Then, the distance calculation unit 7h compares the minimum distance with the threshold value, and when the minimum distance is less than the threshold value, the display 8 presents information 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 portion where the minimum distance is obtained and the displacement amount of the fuel pipe 4 required to make the minimum distance greater than the threshold value, and presents the information on the display 8. Thus, when the minimum distance is less than the threshold value, the operator can accurately displace the fuel pipe 4 toward the desired position while observing the fuel pipe 4 displayed on the display 8. In addition, the information indicating that the minimum distance is less than the threshold value is presented through sound and vibration, so that the operator can recognize that the minimum distance is less than the threshold value while continuing to work without looking away.

[0066] In addition, in the present embodiment, after roughly registering the point cloud data generated based on the design data of the area including the ignition coil 3 and the fuel pipe 4 with the point cloud data of the area acquired by scanning as the measurement data using key points, the point cloud data of the ignition coil 3 based on the design data is registered with the point cloud data of the ignition coil 3 extracted from the measurement data, and the point cloud data of the fuel pipe 4 based on the design data is registered with the point cloud data of the fuel pipe 4 extracted from the measurement data as a non-rigid body. That is, after the positional relationship between the ignition coil 3 and the fuel pipe 4 in the scanned area is acquired in the rough registration, detailed registration is performed for each. 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 pipe 4.

[0067] Furthermore, in the present embodiment, the minimum distance between the ignition coil 3 and the fuel pipe 4 is checked during the whole vehicle inspection process of the automobile. During the whole vehicle inspection of the automobile, the ignition coil 3 and the fuel pipe 4 have been assembled together with various components such as the intake manifold 2, and the ignition coil 3 is located in a difficult-to-measure position that is deeper than the intake manifold 2 when viewed from the upper side of the engine compartment 1. Furthermore, the fuel pipe 4 is a non-rigid body with deformation, and therefore, is difficult to measure compared to a rigid body. Therefore, by using the gap inspection method of the present embodiment, the minimum distance between the two can be efficiently checked during the whole vehicle inspection process of the automobile including the ignition coil 3 and the fuel pipe 4 that are difficult to measure, and the time spent on the whole vehicle inspection process of the automobile can be shortened compared to the case where the operator performs the inspection using, for example, a ruler.

[0068] Furthermore, in the present embodiment, the designed minimum distance between the ignition coil 3 and the fuel pipe 4 may be defined at a position of an outer surface of at least one of the ignition coil 3 and the fuel pipe 4 that cannot be visually confirmed from the outside. Even in the case of such an outer surface that cannot be visually confirmed including the ignition coil 3 and the fuel pipe 4, the minimum distance between the ignition coil 3 and the fuel pipe 4 can be calculated as long as the outer surface that cannot be visually confirmed is filled using the first filling portion 7f and the second filling portion 7g of the gap inspection device of the present embodiment.

[0069] In addition, in this embodiment, an example of calculating the distance between the ignition coil 3 as a rigid body and the fuel pipe 4 as a non-rigid body is disclosed, but the distance between other rigid body components and non-rigid body components arranged in the engine compartment 1 can also be calculated.

[0070] In the present embodiment, an example of non-rigid registration of the fuel pipe 4 having a circular radial cross section is described. However, the present invention can also be applied to non-rigid registration of pipes having a rectangular radial cross section other than a circular shape.

[0071] In addition, in the present embodiment, an example of calculating the distance between a rigid body component and a non-rigid body component of a car is disclosed. However, the distance between a rigid body component and a non-rigid body component other than a car may be calculated.

[0072] Furthermore, in the above-described embodiment, an example is described in which an operator operates the three-dimensional laser scanner 5 by hand, but the present invention is also applicable when a robot performs scanning using a three-dimensional sensor.

[0073] In addition, in this embodiment, the three-dimensional laser scanner 5 is described as a three-dimensional sensor, but other types of three-dimensional sensors, such as a ToF type three-dimensional sensor, a three-dimensional sensor of a triangulation type such as a stereo camera, etc., can be widely applied.

Claims

1. A gap inspection method for inspecting a distance between a first component and a second component in an assembly formed by assembling a plurality of components including a first component as a rigid body and a second component as a non-rigid body, wherein: Scanning an area including the first component and the second component from the outside using a three-dimensional sensor to obtain measurement data including a portion of the outer surface of each component, acquiring design data including the outer shapes of the first component and the second component and the positional relationship between the first component and the second component in the assembly, registering the design data of the first component as a rigid body to the position of the measurement data of the first component, and generating an outer shape of the first component including a hidden outer surface portion, registering the design data of the second component as a non-rigid body to the position of the measurement data of the second component, and generating an outer shape of the second component including a hidden outer surface portion, The distance between an arbitrary point of the first component and an arbitrary point of the second component is calculated.

2. The gap inspection method according to claim 1, wherein: The method further includes calculating a minimum distance between the first component and the second component.

3. The gap inspection method according to claim 2, wherein: The method further includes comparing the minimum distance with a threshold value, and presenting information on a situation where the minimum distance is less than the threshold value when the minimum distance is less than the threshold value.

4. The gap inspection method according to claim 3, wherein: The method further includes calculating, when the minimum distance is smaller than the threshold, a location where the minimum distance occurs and an amount of displacement of the second member required to make the minimum distance equal to or greater than the threshold, and presenting the information.

5. The gap inspection method according to claim 3, wherein: The method further includes: when presenting information for a situation where the situation is less than the threshold, presenting the information using one or more of an image, a sound, and a vibration.

6. The gap inspection method according to claim 1, wherein: After roughly registering point cloud data generated from design data of a region including the first component and the second component with point cloud data of a region acquired by scanning as measurement data using key points, The point cloud data of the first component based on the design data is registered with the point cloud data of the first component extracted from the measurement data, and the point cloud data of the second component based on the design data is registered as a non-rigid body with the point cloud data of the second component extracted from the measurement data.

7. The gap inspection method according to claim 1, wherein: The assembly is an automobile, the second member is a pipe disposed in an engine room, and the first member is a member in the engine room for which a minimum distance from the pipe is specified.

8. The gap inspection method according to claim 1, wherein: During a complete vehicle inspection of the motor vehicle, a minimum distance between the first component and the second component is checked.

9. The gap inspection method according to claim 1, wherein: The minimum distance between the first member and the second member in design is defined at a position of an outer surface of at least one of the first member and the second member that cannot be visually recognized from the outside.

10. A gap inspection device for inspecting a distance between a first component and a second component in an assembly formed by assembling a plurality of components including a first component as a rigid body and a second component as a non-rigid body, the gap inspection device comprising: a three-dimensional sensor that scans an area including the first component and the second component from the outside to acquire measurement data including a portion of an outer surface of each component; a database storing design data including the outer shapes of the first component and the second component and the positional relationship between the first component and the second component within the assembly; a rigid body registration unit for registering the design data of the first component as a rigid body to the position of the measurement data of the first component; a first filling unit filling the hidden outer surface portion of the first component based on the design data of the first component to generate an outer shape of the first component including the hidden outer surface portion; a non-rigid body registration unit, which registers the design data of the second component to the position of the design data of the second component as a non-rigid body; a second filling unit filling the hidden outer surface portion of the second component based on the design data of the second component to generate an outer shape of the second component including the hidden outer surface portion; as well as The distance calculation unit calculates a distance between an arbitrary point of the first member and an arbitrary point of the second member.

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