JP2006059014A - Device for calculating distance of three-dimensional cad data and measured three-dimensional data, distance calculating method, and its program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve shape evaluation in relation between a design reference surface and its slave surface concerning the whole surfaces of a three-dimensional shape object having not less than two design reference surfaces in a coaxial direction. <P>SOLUTION: A distance calculating device positions the three-dimensional CAD data and measured three-dimensional data of the three-dimensional shape object so as to calculate mutual distances. A three-dimensional CAD data storage means 6 stores the design reference surface and the slave surface, to which relating information for marking the design reference surface is given, as the three-dimensional CAD data. A measured three-dimensional data storage means 7 stores the measured three-dimensional data, and also, stores information which is obtained by relating the measured three-dimensional data to the design reference surface and the slave surface, respectively, by a relating means 8. A positioning means 9 positions the measured three-dimensional data on the basis of the design reference surface and the measured three-dimensional data related to the deign reference surface. A distance calculating means 10 calculates the distance between the positioned slave surface and the measured three-dimensional data related to the slave surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is used for, for example, shape evaluation and pass / fail judgment of a three-dimensional shaped object such as a molded product, and calculates the distance between the three-dimensional CAD data of the three-dimensional shaped object and the measured three-dimensional data. The present invention relates to a distance calculation device, a distance calculation method, and a distance calculation program for dimensional CAD data and measured three-dimensional data.

  Conventionally, when a processing accuracy is evaluated by comparing a three-dimensional object processed based on three-dimensional CAD data with the three-dimensional CAD data, the three-dimensional object is represented by three-dimensional space coordinates. A method is employed in which each point is converted into a set of points and the distance between each point and three-dimensional CAD data is calculated to calculate each other's distance. (For example, patent document 1).

  More specifically, first, the surface shape of a three-dimensional object is scanned by a contact-type three-dimensional measurement device or a non-contact-type three-dimensional measurement device to obtain a three-dimensional spatial coordinate value, and this is obtained as measurement three-dimensional data. To do. Next, a three-dimensional image of the three-dimensional CAD data of the three-dimensional object and a three-dimensional image formed by each point of the measurement three-dimensional data are displayed on a monitor or the like.

  Next, the measurement three-dimensional data is moved to a position where the sum of squares of the distance to the three-dimensional CAD data is minimized for any three surfaces in different axial directions of the stereoscopic image of the three-dimensional CAD data. The operation of moving the measured three-dimensional data with respect to the three-dimensional CAD data is referred to as alignment, and the error sum of squares of the distance from the surface serving as a reference for the alignment, that is, the measured three-dimensional data is calculated. The design reference plane of the three-dimensional CAD data is used as the plane to be minimized.

  Here, in general, the design reference plane refers to a plane that serves as a reference in defining the dimensions of each surface constituting the three-dimensional shape object when designing an actual three-dimensional shape object. The design reference plane of the three-dimensional CAD data refers to the three-dimensional CAD data corresponding to the design reference plane of the three-dimensional shape object, and is a plane that serves as a reference when aligning the measured three-dimensional data (for example, Patent Document 2). Further, among the surfaces of the three-dimensional shape object, a surface whose dimension is defined based on the design reference surface is referred to as a dependent surface.

Thereafter, the three-dimensional CAD data aligned as described above and the measured three-dimensional data are compared, and processing accuracy is obtained based on the distance of the measured three-dimensional data with respect to the three-dimensional CAD data. If necessary, the evaluation result is displayed to the user so that the evaluation result can be visually recognized by color-coding according to the distance between the three-dimensional CAD data and the measured three-dimensional data.
Japanese Patent No. 30579960 JP 2001-82951 A

  However, in the conventional three-dimensional shape evaluation method described above, the three-dimensional shape object to be evaluated for machining accuracy actually has a plurality of design reference planes in the coaxial direction, and the three-dimensional shape object has a dimensional error. In the case where there is an error, the distance from each dependent surface to the corresponding three-dimensional CAD data can be calculated and the dimensional error can be evaluated, but the reference for the alignment of the three-dimensional CAD data and the measured three-dimensional data There is a problem that it is impossible to evaluate whether or not the dimension from the design reference plane that does not become the dependent plane is appropriate.

  For example, as shown in FIGS. 3A, 3B, and 3C, it is assumed that the three-dimensional shape has a shape in which square holes are formed on the upper surface of a rectangular parallelepiped. The surface B and the surface C of the three-dimensionally shaped object are dimensionally defined based on the surface A, and the surface D is dimensionally defined based on the surface C. That is, surface A and surface C are design reference surfaces, surface B and surface C are dependent surfaces of surface A, and surface D is a dependent surface of surface C.

  Under such a premise, in order to evaluate the shape of whether or not the square hole of the three-dimensional shape has been machined to a size suitable for inserting a square member (not shown), it is necessary to determine from the C plane that forms the square hole to D It is necessary to calculate the distance to the surface and evaluate whether this is within the allowable range.

  However, in the above-described conventional three-dimensional shape evaluation method, the three-dimensional CAD data and the measured three-dimensional shape of the three-dimensional shape object based on only the surface A out of the two design reference surfaces A and C. Since the data is aligned, for example, when there is a dimensional error between the surface A and the surface C of the three-dimensional shape object, the dimensional error is a dependent surface of the surface A in the alignment process. It extends to plane C and plane D. For this reason, even if the dimension from the surface C to the surface D is processed within the allowable range, it is uniformly evaluated as defective based on the distance between the measured three-dimensional data and the three-dimensional CAD data. It was not possible to properly evaluate the dimensions from the design reference plane, which is not the reference, to the dependent plane.

  The present invention has been made in view of the above problems, and 3D CAD data and measurement capable of performing appropriate shape evaluation on all surfaces of a 3D shape object having a plurality of design reference surfaces in the coaxial direction. It is an object to provide a distance calculation device, a distance calculation method, and a distance calculation program for three-dimensional data.

  In order to achieve the above object, the distance calculation apparatus for 3D CAD data and measured 3D data according to the present invention calculates the distance between the 3D CAD data and the measured 3D data of a 3D shape object by aligning them. 3D CAD data storage for storing a design reference plane and a dependent plane provided with association information for indicating the design reference plane as the three-dimensional CAD data in a distance calculation apparatus between the three-dimensional CAD data to be measured and the measured three-dimensional data And means for storing the measurement three-dimensional data storage means for storing the measurement three-dimensional data, and information for associating the measurement three-dimensional data with the design reference plane or the dependent plane, respectively, in the measurement three-dimensional data storage means The design reference plane and the design reference plane are matched with the design reference plane and the design three-dimensional data associated with the design reference plane. Alignment means for aligning the attached measurement three-dimensional data, the dependent surface and the measurement three-dimensional data associated with the dependent surface, the measured dependent surface and the measurement 3 associated with the dependent surface A distance calculating means for calculating the distance of the dimension data is provided.

  Preferably, the positioning means associates the design reference plane with the design reference plane so that a distance between the design reference plane and the measurement three-dimensional data associated with the design reference plane is minimized. The coordinate calculation is performed on the measurement three-dimensional data, the dependent surface, and the position of the measurement three-dimensional data associated with the dependent surface, and the distance calculation unit is configured to convert the dependent surface and the dependent surface based on the converted coordinates. The distance of the measurement three-dimensional data associated with is calculated.

  Preferably, the three-dimensional CAD data storage means stores a plurality of the design reference planes, assigns association information indicating one design reference plane to another design reference plane, and the positioning means Using the one design reference plane and the measurement three-dimensional data associated with the one design reference plane as a reference, the other design reference plane and the three-dimensional measurement data associated with the other design reference plane and the one design reference plane The dependent plane associated with the design reference plane is aligned with the measurement three-dimensional data corresponding to the dependent plane, and the measurement three-dimensional data associated with the other design reference plane and the other design reference plane Is used as a reference, and a dependent surface associated with the other design reference surface is aligned with the measurement three-dimensional data corresponding to the dependent surface.

  Preferably, a plurality of the design reference planes are stored, and the three-dimensional CAD data storage means in which association information indicating one design reference plane is given to another design reference plane, the one design reference plane, and the Using the three-dimensional measurement data associated with one design reference plane as a reference, the one design reference plane and the three-dimensional measurement data associated with the one design reference plane, the other design reference plane and the other The measurement three-dimensional data associated with the design reference plane, and the alignment means for aligning the dependent plane and the measurement three-dimensional data associated with the dependent plane, and the other design reference plane aligned Correction distance calculating means for calculating a distance between the measured three-dimensional data associated with the other design reference plane, and calculating the distance between the aligned dependent plane and the measured three-dimensional data associated with the dependent plane Distance A calculation unit, on the basis of the corrected distance distance calculating means is calculated, a structure in which a correcting means for correcting the distance which the distance calculating means has calculated.

  Preferably, the correction distance calculation unit calculates an average distance between the other design reference plane and the measurement three-dimensional data associated with the other design reference plane, and the correction unit includes the distance calculation unit The calculated distance is corrected by adding or subtracting the average distance calculated by the correction distance calculating means.

  Preferably, the design reference plane and dependent plane association information, the configuration in which the one and other design reference plane association information is included in three-dimensional CAD data, or the design reference plane and dependent plane association information, And an input means for inputting association information between other design reference planes.

  In order to achieve the above object, the distance calculation method between the three-dimensional CAD data and the measured three-dimensional data according to the present invention aligns the three-dimensional CAD data of the three-dimensional shape object and the measured three-dimensional data, and distances each other. Storing a design reference plane and a dependent plane to which association information indicating the design reference plane is added as the three-dimensional CAD data in the distance calculation method between the three-dimensional CAD data and the measured three-dimensional data. Storing the measurement three-dimensional data, storing information in which the measurement three-dimensional data is associated with the design reference plane or the dependent plane, the design reference plane, and the design reference plane Using the measurement three-dimensional data as a reference, the measurement reference surface and the measurement three-dimensional data associated with the design reference surface, and the measurement 3 associated with the dependent surface and the dependent surface Aligning the original data, there a procedure comprising the step of calculating the distance measured three-dimensional data associated with the slave surface and the driven metal surface which aligned.

  Preferably, a plurality of the design reference planes are stored, association information indicating one design reference plane is given to another design reference plane, the one design reference plane, and the one design reference plane Corresponding to the one design reference plane and the one measurement reference plane, the other design reference plane and the other design reference plane based on the corresponding measurement three-dimensional data The measured three-dimensional data attached, and the step of aligning the dependent plane and the measured three-dimensional data associated with the dependent plane; corresponding to the aligned other design reference plane and the other design reference plane Calculating the distance of the attached measurement three-dimensional data, calculating the distance between the aligned dependent surface and the measurement three-dimensional data associated with the dependent surface, the other design reference plane, Map to other design reference plane Based on the distance of the measuring three-dimensional data, the procedure including the step of correcting the distance of the measured three-dimensional data associated with the slave surface and the driven metal surface.

  Furthermore, in order to achieve the above object, the distance calculation program for the three-dimensional CAD data and the measured three-dimensional data according to the present invention aligns the three-dimensional CAD data and the measured three-dimensional data of the three-dimensional shape object to each other. In the program for causing a computer to calculate the distance between the three-dimensional CAD data for calculating and the measured three-dimensional data, the design reference plane and the dependent plane to which the association information indicating the design reference plane is given Storing as CAD data; storing the measurement three-dimensional data; storing information in which the measurement three-dimensional data is associated with the design reference plane or the dependent plane; and the design reference plane; Using the measurement three-dimensional data associated with the design reference plane as a reference, the design reference plane and the measurement three-dimensional data associated with the design reference plane And a step of aligning the dependent surface and the measured three-dimensional data associated with the dependent surface, and calculating a distance between the aligned dependent surface and the measured three-dimensional data associated with the dependent surface; Is executed on a computer.

  Preferably, a plurality of the design reference planes are stored, association information indicating one design reference plane is given to another design reference plane, the one design reference plane, and the one design reference plane Corresponding to the one design reference plane and the one measurement reference plane, the other design reference plane and the other design reference plane based on the corresponding measurement three-dimensional data The measured three-dimensional data attached, and the step of aligning the dependent plane and the measured three-dimensional data associated with the dependent plane; corresponding to the aligned other design reference plane and the other design reference plane Calculating the distance of the attached measurement three-dimensional data, calculating the distance between the aligned dependent surface and the measurement three-dimensional data associated with the dependent surface, the other design reference plane, Map to other design reference plane Based on the distance of the measuring three-dimensional data, so as to execute a step of correcting the distance of the measured three-dimensional data associated with the slave surface and the driven metal surface on the computer.

  According to the distance calculation apparatus, the distance calculation method, and the distance calculation program for the three-dimensional CAD data and the measured three-dimensional data according to the present invention, the three-dimensional shape object to be evaluated for machining accuracy has a plurality of design reference planes in the coaxial direction. Even if it has, associating information between design reference plane and dependent plane as 3D CAD data, or design reference plane, alignment of 3D CAD data and measurement 3D data, and 3D CAD data and measurement 3D data Therefore, it is possible to optimize the shape evaluation in the relationship between the design reference plane and its dependent plane.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a distance calculation apparatus, a distance calculation method, and a distance calculation program for 3D CAD data and measurement 3D data according to the present invention will be described in detail with reference to the drawings.
<Embodiment 1>
FIG. 1 is a block diagram showing a distance calculation apparatus for 3D CAD data and measured 3D data according to the present embodiment. In this figure, the distance calculation device 1 includes a CPU 2, a memory 3, an input means 4, an output means 5, a three-dimensional CAD data storage means 6, a measurement three-dimensional data storage means 7, an association means 8, an alignment means 9 and The distance calculation means 10 is provided, which is connected to a CAD device 11 and a measurement three-dimensional data acquisition device 12. These devices can be connected to each other via a network such as a cable or a wireless LAN, or can exchange data with a portable recording medium such as a disk.

  As the CAD apparatus 11, an information processing apparatus such as a personal computer or a workstation capable of executing three-dimensional CAD software can be used. As the measurement three-dimensional data acquisition device 12, for example, a probe-type three-dimensional measurement device, a laser-type three-dimensional digitizer, a camera-type three-dimensional digitizer, or the like can be used. The measurement three-dimensional data acquisition device 12 scans a three-dimensional object such as a component of various equipment and its housing, for example, so that the three-dimensional object is a set of point data having three-dimensional coordinates. Some measured three-dimensional data is used. In this embodiment, the measurement three-dimensional data is point data. However, the present invention is not limited to this, and the present invention can be applied even when line data, surface data, or the like is used as the measurement three-dimensional data. Is possible.

  Such a distance calculation device 1 is realized by an information processing device such as a personal computer or a workstation. The CPU 2 controls the entire distance calculation device 1 by executing a control program stored in the memory 3. In addition to the control program, the memory 3 stores data read from the CAD device 11 or the measurement three-dimensional data acquisition device 12. The input unit 4 is a unit for the user to input data, such as a keyboard or a pointing device. The output means 5 is, for example, a monitor such as a liquid crystal display or a CRT display, and outputs data such as three-dimensional CAD data, measurement three-dimensional data, and evaluation results.

  The three-dimensional CAD data storage means 6 stores, as three-dimensional CAD data, a design reference surface of a three-dimensional shape object and a dependent surface to which association information indicating the design reference surface is given. The measurement three-dimensional data storage means 7 stores measurement three-dimensional data. The association unit 8 associates the measurement three-dimensional data with the design reference plane or the dependent plane, and stores the association information in the measurement three-dimensional data storage unit. The alignment means 9 uses the design reference plane and the measurement three-dimensional data associated with the design reference plane as a reference, the design reference plane, the measurement three-dimensional data associated with the design reference plane, the dependent plane, and the The measurement three-dimensional data associated with the dependent plane is aligned. The distance calculation means 10 calculates the distance between the aligned dependent surface and the measured three-dimensional data associated with the dependent surface.

  FIG. 2 is a flowchart showing the operation of the three-dimensional shape evaluation apparatus according to this embodiment. The outline of the distance calculation process between the three-dimensional CAD data and the measured three-dimensional data will be described below with reference to FIG.

  First, in step S1, 3D CAD data is read. Three-dimensional CAD data, which is design data for a three-dimensional object, is stored in the memory 3 from the CAD device 11 via a network such as a LAN or a recording medium.

  Next, in step S2, the measurement three-dimensional data is read. The measurement three-dimensional data acquired by scanning the actually processed three-dimensional shape object from the measurement three-dimensional data acquisition device 12 is stored in the memory 3 via a network such as a LAN or a recording medium.

  In step S3, a dependent surface of the three-dimensional CAD data is selected, and then a design reference surface used for designing the dependent surface is selected. The dependent surface selected by this process is associated with the design of the selected design reference surface. The association information indicating the design reference plane may be included in the three-dimensional CAD data in advance or may be input from an input unit such as a keyboard.

  3A, 3B, and 3C are drawings for explaining a design reference plane and a dependent plane that is designed by defining a dimension based on the design reference plane. FIG. 3A is a perspective view of a three-dimensional shape object. 3B is a top view of the three-dimensional shape object of FIG. 3A, and FIG. 3C is a side view of FIG. 3A.

  In these drawings, there are a surface A, a surface B opposed to the surface A, a surface C and a surface D parallel to the surface A at the concave portions. The plane C is closer to the plane A than the plane D. It is assumed that the surface B and the surface C are evaluated by the distance from the surface A, and the surface D is evaluated by the distance from the surface C. In this case, the surface B and the surface C of the three-dimensionally shaped object are dimensionally defined with respect to the surface A, and the surface D is dimensionally defined with respect to the surface C. That is, surface A and surface C are design reference surfaces, surface B and surface C are dependent surfaces of surface A, and surface D is a dependent surface of surface C.

  The user selects the dependent surface and the design reference surface used to design the dependent surface from the 3D CAD data displayed on the monitor or the like via a pointing device or the like. The shape evaluation for the selected dependent surface is made based on the distance from the next selected design reference surface. Here, all the dependent surfaces are associated with the design reference surface, but there is a dependency relationship such as the above-described A surface (one design reference surface) and C surface (other design reference surfaces). When there are a plurality of design reference planes, these design reference planes are associated with each other. For example, in FIG. 3A, although the surface C is the design reference surface of the surface D, the surface C itself is evaluated by the surface A, so that the surface C is a dependent surface having the surface A as the design reference surface. Make an association.

  In step S4, the user associates the design reference plane and the dependent plane with the corresponding measurement three-dimensional data. The user selects the design reference plane and the dependent plane displayed on the output unit 5 by using a pointing device or the like, and then selects the corresponding measurement three-dimensional data, for example, by surrounding it with a rectangle. Thus, the association is performed. All design reference planes and dependent planes are associated with measured three-dimensional data.

  In step S5, a coordinate transformation matrix for aligning the measurement three-dimensional data associated with the design reference plane is obtained. Specifically, a perpendicular is drawn from the measured three-dimensional data associated with the design reference plane to the design reference plane, the distance from the measured three-dimensional data to the intersection of the perpendicular and the design reference plane is obtained, and the square of the distance is obtained. Find the coordinate transformation matrix that minimizes the sum. In step S5, coordinate transformation matrices are obtained for the number of design reference planes. Here, when the surface is a design reference surface in relation to the surface D as in the surface C described above, but is a dependent surface in the relationship with the surface A, the surface C is handled as the design reference surface of the surface D. A coordinate conversion sequence for aligning the measurement three-dimensional data associated with the surface C with the surface C is obtained.

  In step S6, using the coordinate transformation matrix obtained in the previous step S5, coordinate transformation of the measurement three-dimensional data respectively associated with the design reference plane or the dependent plane is performed. Here, as in the case of the surface C described above, when the surface is a design reference surface in relation to the surface D but is a dependent surface in the relationship with the surface A, the surface C is handled as a dependent surface of the surface A. Using the coordinate transformation matrix of the measurement three-dimensional data associated with the surface A obtained in the previous step S5, the coordinate transformation of the measurement three-dimensional data of the surface C is performed.

  In step S7, a perpendicular is drawn from the measurement three-dimensional data coordinate-transformed in the previous step S6 to the dependent surface associated therewith, and the intersection of the perpendicular and the dependent surface is obtained from the measurement three-dimensional data. In step 8, the distance from the measured three-dimensional data to the intersection of the perpendicular and the dependent surface is obtained.

  In step S9, the result of shape evaluation is displayed by color coding or the like according to the distance obtained in the previous step S8, and the process ends. Here, when there is a dimensional error exceeding the allowable range between the surface A and the surface C, the measurement three-dimensional data associated with the surface C is the coordinate transformation matrix of the measurement three-dimensional data associated with the surface A. Since the coordinate conversion is performed using, it is evaluated as “defective” under the influence of the dimensional error. On the other hand, the measurement three-dimensional data associated with the surface D is coordinated using the coordinate transformation matrix of the measurement three-dimensional data associated with the surface C for alignment with the surface C as a design reference surface. Since conversion is performed, it is evaluated as “good” without being affected by the dimensional error. That is, the distance or dimension from the surface C that is the design reference surface to the surface D that is the dependent surface is appropriately evaluated.

  Note that the reading of the three-dimensional CAD data in step S1 and the reading of the measurement three-dimensional data in step S2 are not limited to the above order, and step S1 may be executed after step S2 is executed first.

Hereinafter, the structures of the three-dimensional CAD data and the measured three-dimensional data will be described with reference to FIGS.
FIG. 4 is a structural diagram of a directory section of three-dimensional CAD data. As the format of the three-dimensional CAD data, for example, IGES (Initial Graphic Exchange Specification) widely used as an intermediate format between different types of CAD is used. The data format of IGES is an ASCII text file of 80 bytes per record (one card). The IGES is classified into a start section, a global section, a directory section, a parameter section, and a terminate section. The start section is used to describe a data name, data generation date and time, and the like. The global section is used to transmit the system information of the system that generated the IGES file to the receiving system. The directory section stores attribute information such as element type, layer, and line font of CAD data representing a three-dimensional shape. Specific CAD data is stored in the parameter section. The terminator section manages the number of cards (number of records) included in the previous four sections.

  As shown in FIG. 4, the data stored in the directory section of the three-dimensional CAD data is composed of two records per element, that is, one unit of CAD data stored in the parameter section. Each record is described in a fixed field format divided into 10 fields composed of 8 characters. Among these, the 16th parameter stores the sequence number of the design reference plane that is used as a reference when the element plane is evaluated. Here, the sequence number refers to a number indicating the order of cards. The sequence number starts at 1 and increases by 1 for each card.

  FIG. 5 is a data structure diagram of measured three-dimensional data obtained by scanning a three-dimensional shape object created from three-dimensional CAD data according to the present embodiment. The measured three-dimensional data is an ASCII text file. A three-dimensional shape is regarded as a set of points, for example, and is represented by one record per point. One record of the measured three-dimensional data is composed of four parameters and is described in a fixed field format divided into four fields. As the first parameter, the coordinate value of the measured three-dimensional data is stored. In the second parameter, the sequence number of the directory section of the associated design reference plane and dependent plane is stored as correlation information. The third parameter stores the coordinate value of the intersection point of the perpendicular line and the dependent surface that are lowered from the measured three-dimensional data to the associated dependent surface. The fourth parameter stores the distance between the point represented by the first parameter and the point represented by the third parameter. Initially, at the stage where the measured data is scanned by the measurement three-dimensional data acquisition device 12 and the obtained data is stored in the memory 3 of FIG. 1, only the value of the first parameter is stored. In accordance with the processing of FIG. 2, values are sequentially stored from the second parameter to the fourth parameter. The measurement three-dimensional data coordinate-transformed in step S6 in FIG. 2 is overwritten on the first parameter.

  The 16th parameter of the directory section of the three-dimensional CAD data shown in FIG. 4 stores the sequence number of a surface (design reference surface) that is used as a reference when a certain surface is evaluated. When the design reference plane and the dependent plane are associated with the measurement three-dimensional data, the sequence numbers of the associated design reference plane and the dependent plane are stored as the second parameter of the measurement three-dimensional data in FIG. The

  First, a coordinate transformation matrix that minimizes the sum of squares of the distance between the design reference plane and the measured three-dimensional data associated therewith is obtained. Based on the obtained coordinate transformation matrix, the measurement reference plane and the measured three-dimensional data associated with the plane designed on the basis of the design reference plane are coordinate transformed by the coordinate transformation matrix. The coordinate value of the intersection point between the perpendicular line and the dependent surface, which is drawn from the coordinate-converted measurement three-dimensional data to the dependent surface associated with the measurement three-dimensional data, is the third parameter, and the distance between the measurement three-dimensional data and the intersection point is the third parameter. Stored in 4 parameters. Based on the value of the fourth parameter, display is performed by color coding or the like.

As described above, according to the distance calculation apparatus between the three-dimensional CAD data and the measured three-dimensional data according to this embodiment, the three-dimensional shape object having the design reference surface having two or more design reference surfaces in the coaxial direction. By aligning each design reference plane using the association information indicating the design reference plane held by the subordinate plane, the distance from the design reference plane is within the allowable range for all planes. It is possible to determine whether or not there is.
<Embodiment 2>
First, the difference between the above-described first embodiment and the second embodiment described below will be briefly described. In the first embodiment, the positions of the three-dimensional CAD data and the measured three-dimensional data are each based on a plurality of design reference planes. The distance was calculated and the distance was calculated. On the other hand, in the second embodiment, the three-dimensional CAD data and the measurement three-dimensional data are aligned by using one design reference plane as a reference among the plurality of design reference planes. When calculating the distance to the dimensional data, there is a difference in that correction is performed using the distance between the other design reference plane that has not become the alignment reference and the measured three-dimensional data associated therewith.

  In the following, the distance calculation apparatus, the distance calculation method, and the distance calculation program for the three-dimensional CAD data and the measured three-dimensional data according to the second embodiment will be described with a focus on differences from the first embodiment. The configuration of the distance calculation device is substantially the same as that of the distance calculation device shown in FIG. Other parts similar to those of the first embodiment will be described with reference to the same figure numbers.

  FIG. 6 is a flowchart showing the operation of the distance calculation apparatus for 3D CAD data and measured 3D data according to this embodiment. With reference to FIG. 6, the process of the distance calculation apparatus 1 which concerns on this embodiment is demonstrated. At that time, FIG. 7 is used as an example of a three-dimensional shape.

  FIG. 7 is a side view of the three-dimensional shape object. The right direction in the figure is the positive x-axis direction. Assume that the distance between surface C and surface D in the figure is evaluated. Regarding the surface C and the surface D, in the figure, the solid line represents the three-dimensional CAD data, and the broken line represents the actual measurement three-dimensional data. For the other surfaces, the measurement three-dimensional data is omitted. In plane A, the three-dimensional CAD data and the measured three-dimensional data are aligned.

  First, since the process from step S11 to step S14 is the same process as Embodiment 1, detailed description is abbreviate | omitted. In step S15, among the design reference planes constituting the three-dimensional CAD data, a measurement reference associated with a design reference plane (one design reference plane, for example, plane A in FIG. 7) for which there is no upper design reference plane. A coordinate transformation matrix that minimizes the sum of squares of the distance to the three-dimensional data is obtained. In step S16, all the measured three-dimensional data are coordinate-transformed using the coordinate transformation matrix obtained in the previous step S15.

  The processing in steps S17 and S18 is the same as that in steps S7 and S8 in FIG. 2, and the perpendicular and the dependent surface drawn with respect to the dependent surface (for example, the surface D in FIG. 7) associated with each measurement three-dimensional data. , The measured three-dimensional data, and the distance between the intersection and the intersection are obtained by each processing. The distance obtained in step S18 corresponds to X in FIG.

  In step S19, the average distance between the design reference planes other than the design reference plane used in step S15 (other design reference planes, for example, the plane C in FIG. 7) and the measured three-dimensional data associated therewith (ΔXave in FIG. 7) is obtained. The average value has a minus sign when the measured three-dimensional data is on the design reference plane side higher than the design reference plane. The average value is calculated for each design reference plane.

  In step S20, the distance between the design reference plane obtained in step S19 and the measured three-dimensional data associated with the design reference plane from the distance X between the dependent plane associated with the measurement three-dimensional data obtained in step S18. Is obtained by subtracting the average value ΔXave (average distance, X − (− ΔXave) = X + ΔXave in FIG. 7).

  In step S21, the result is displayed by color coding or the like according to the distance obtained in the previous step S20, and the process ends. Here, as shown in FIG. 7, when there is a dimensional error (−ΔXave in FIG. 7) that exceeds the allowable range between the surfaces A and C, the measured three-dimensional data associated with the surface C is Since the coordinate transformation is performed using the coordinate transformation matrix of the measurement three-dimensional data associated with A, it is evaluated as “bad” due to the influence of the dimensional error. On the other hand, the measured three-dimensional data associated with the surface D is corrected to the average distance (X + ΔXave) and the distance is calculated up to the three-dimensional CAD data, so that it is “good” without being affected by the dimensional error. It is evaluated. That is, the distance or dimension from the surface C that is the design reference surface to the surface D that is the dependent surface is appropriately evaluated.

  FIG. 8 is a data structure diagram of measurement three-dimensional data according to the present embodiment. The structure diagram of the three-dimensional CAD data is the same as the structure according to FIG. 4 of the first embodiment, and a description thereof will be omitted.

  In FIG. 8, the first parameter to the fourth parameter are the same as the data structure of FIG. 5, and therefore only the fifth and sixth parameters will be described here. The fifth parameter is an average value of the distance between the design reference plane associated with the dependent plane associated with the measurement three-dimensional data and the measurement three-dimensional data associated with the design reference plane (in FIG. 7). ΔXave) is stored. The sixth parameter includes a design reference plane associated with the dependent plane associated with the measurement three-dimensional data and the value X stored in the fourth parameter, and the measurement 3 associated with the design reference plane. A value (X + ΔXave in FIG. 7) obtained by subtracting the average value of the distance from the dimension data is stored.

  In FIG. 7, even when the surface C needs to calculate the distance by calculating the distance with respect to the surface A, and the surface F needs to calculate the distance by calculating the distance with respect to the surface E, the surface error Distance calculation is possible for both C and surface F.

  As described above, according to the distance calculation apparatus, the distance calculation method, and the distance calculation program between the three-dimensional CAD data and the measured three-dimensional data according to the first and second embodiments, the three-dimensional shape object to be evaluated for machining accuracy. However, even when there are a plurality of design reference planes in the coaxial direction, the alignment information between the design reference plane and the dependent plane as the three-dimensional CAD data or the design reference planes is aligned between the three-dimensional CAD data and the measured three-dimensional data. Further, by using it for calculating the distance between the three-dimensional CAD data and the measured three-dimensional data, it is possible to optimize the shape evaluation in the relationship between the design reference plane and its dependent plane.

It is a block diagram of the distance calculation apparatus of 3D CAD data and measurement 3D data concerning Embodiment 1. 6 is a flowchart showing the operation of the distance calculation apparatus between the three-dimensional CAD data and the measured three-dimensional data according to the first embodiment. It is an example of the perspective view of a three-dimensional shape thing. It is a top view of the three-dimensional shape object of FIG. 3A. It is a side view of the three-dimensional shape object of FIG. 3A. It is a structure figure of the directory section of three-dimensional CAD data. 3 is a data structure diagram of measured three-dimensional data according to Embodiment 1. FIG. 10 is a flowchart showing the operation of the distance calculation device between the three-dimensional CAD data and the measured three-dimensional data according to the second embodiment. It is a side view of a three-dimensional shape object. 6 is a data structure diagram of measurement three-dimensional data according to Embodiment 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Distance calculation apparatus of 3D CAD data and measurement 3D data 6 3D CAD data storage means 7 Measurement 3D data storage means 8 Association means 9 Positioning means 10 Distance calculation means 11 CAD apparatus 12 Measurement 3D data acquisition apparatus

Claims (11)

In the distance calculation apparatus for 3D CAD data and measurement 3D data, in which the 3D CAD data of the 3D shape and the measurement 3D data are aligned and the distance between them is calculated.
A three-dimensional CAD data storage means for storing a design reference plane and a dependent plane to which association information indicating the design reference plane is given as the three-dimensional CAD data;
Measurement three-dimensional data storage means for storing the measurement three-dimensional data;
Association means for storing in the measurement three-dimensional data storage means information that associates the measurement three-dimensional data with the design reference plane or the dependent plane, respectively;
Based on the design reference plane and the measurement three-dimensional data associated with the design reference plane, the design reference plane and the measurement three-dimensional data associated with the design reference plane, and the dependent plane and the dependent plane Alignment means for aligning the measurement three-dimensional data associated with
A distance calculation device for three-dimensional CAD data and measured three-dimensional data, comprising: the aligned dependent surface and a distance calculating unit that calculates a distance between the measured three-dimensional data associated with the dependent surface.   The alignment means is configured to associate the design reference plane with the design reference plane so that the distance between the design reference plane and the measurement three-dimensional data associated with the design reference plane is minimized. The coordinates of the data, the dependent surface, and the position of the measurement three-dimensional data associated with the dependent surface are coordinate-converted, and the distance calculation means associates the dependent surface with the dependent surface based on the converted coordinates. 2. The distance calculation apparatus between the three-dimensional CAD data and the measured three-dimensional data according to claim 1, wherein the distance between the measured three-dimensional data is calculated. The three-dimensional CAD data storage means stores a plurality of the design reference planes, and gives association information indicating one design reference plane to another design reference plane,
The alignment means uses the one design reference plane and the measurement three-dimensional data associated with the one design reference plane as a reference, and associates the other design reference plane with the other design reference plane. Align the measurement three-dimensional data and the dependent plane associated with the one design reference plane with the measurement three-dimensional data corresponding to the dependent plane, and correspond to the other design reference plane and the other design reference plane 3. The alignment of the dependent plane associated with the other design reference plane and the measured three-dimensional data corresponding to the dependent plane with the measured three-dimensional data attached as a reference. 4. A distance calculation device for 3D CAD data and measured 3D data. A plurality of the design reference planes, and the three-dimensional CAD data storage means for giving association information indicating one design reference plane to another design reference plane;
Based on the one design reference plane and the measurement three-dimensional data associated with the one design reference plane, the measurement three-dimensional data associated with the one design reference plane and the one design reference plane; The positioning means for aligning the other design reference plane and the measurement three-dimensional data associated with the other design reference plane, and the dependent plane and the measurement three-dimensional data associated with the dependent plane;
Correction distance calculation means for calculating a distance between the other design reference plane aligned and the measurement three-dimensional data associated with the other design reference plane;
Distance calculating means for calculating a distance between the aligned dependent surface and the measured three-dimensional data associated with the dependent surface;
The three-dimensional CAD data and measurement according to any one of claims 1 to 3, further comprising correction means for correcting the distance calculated by the distance calculation means based on the distance calculated by the correction distance calculation means. A distance calculation device for three-dimensional data.   The correction distance calculation means calculates an average distance between the other design reference plane and the measurement three-dimensional data associated with the other design reference plane, and the correction means calculates the distance calculated by the distance calculation means. 5. The distance calculation apparatus for three-dimensional CAD data and measurement three-dimensional data according to claim 4, wherein the correction is performed by adjusting the average distance calculated by the correction distance calculation means.   6. The three-dimensional CAD data and measurement according to claim 1, wherein association information between the design reference plane and the dependent plane and association information between the one and another design reference plane are included in the three-dimensional CAD data. A distance calculation device for three-dimensional data.   6. The three-dimensional CAD data and measurement according to claim 1, further comprising input means for inputting association information between the design reference plane and the dependent plane, and association information between the one and another design reference plane. A distance calculation device for three-dimensional data. In the method for calculating the distance between the three-dimensional CAD data and the measured three-dimensional data, the three-dimensional CAD data of the three-dimensional object and the measured three-dimensional data are aligned and the distance between them is calculated.
Storing a design reference plane and a dependent plane provided with association information indicating the design reference plane as the three-dimensional CAD data;
Storing the measured three-dimensional data;
Storing information associating the measurement three-dimensional data with the design reference plane or the dependent plane,
Based on the design reference plane and the measurement three-dimensional data associated with the design reference plane, the design reference plane and the measurement three-dimensional data associated with the design reference plane, and the dependent plane and the dependent plane Aligning the measured three-dimensional data associated with
A method for calculating the distance between the three-dimensional CAD data and the measured three-dimensional data, comprising: calculating the distance between the aligned dependent surface and the measured three-dimensional data associated with the dependent surface. A step of storing a plurality of the design reference planes and giving association information indicating one design reference plane to other design reference planes;
Based on the one design reference plane and the measurement three-dimensional data associated with the one design reference plane, the measurement three-dimensional data associated with the one design reference plane and the one design reference plane; Aligning the other design reference plane with the measurement three-dimensional data associated with the other design reference plane, and the dependent plane with the measurement three-dimensional data associated with the dependent plane;
Calculating a distance between the aligned other design reference plane and the measured three-dimensional data associated with the other design reference plane;
Calculating the distance between the aligned dependent surface and the measured three-dimensional data associated with the dependent surface;
Correcting a distance between the dependent surface and the measurement three-dimensional data associated with the dependent surface based on a distance between the other design reference surface and the measured three-dimensional data associated with the other design reference surface. The method for calculating the distance between the three-dimensional CAD data and the measured three-dimensional data according to claim 8. In a program for causing a computer to calculate the distance between the three-dimensional CAD data and the measured three-dimensional data by aligning the three-dimensional CAD data of the three-dimensional shape and the measured three-dimensional data and calculating the distance between them,
Storing a design reference plane and a dependent plane provided with association information indicating the design reference plane as the three-dimensional CAD data;
Storing the measured three-dimensional data;
Storing information associating the measurement three-dimensional data with the design reference plane or the dependent plane,
Based on the design reference plane and the measurement three-dimensional data associated with the design reference plane, the design reference plane and the measurement three-dimensional data associated with the design reference plane, and the dependent plane and the dependent plane Aligning the measured three-dimensional data associated with
A program for calculating the distance between three-dimensional CAD data and measured three-dimensional data, causing a computer to execute the step of calculating the distance between the aligned dependent surface and the measured three-dimensional data associated with the dependent surface. A step of storing a plurality of the design reference planes and giving association information indicating one design reference plane to other design reference planes;
Based on the one design reference plane and the measurement three-dimensional data associated with the one design reference plane, the measurement three-dimensional data associated with the one design reference plane and the one design reference plane; Aligning the other design reference plane with the measurement three-dimensional data associated with the other design reference plane, and the dependent plane with the measurement three-dimensional data associated with the dependent plane;
Calculating a distance between the aligned other design reference plane and the measured three-dimensional data associated with the other design reference plane;
Calculating the distance between the aligned dependent surface and the measured three-dimensional data associated with the dependent surface;
Correcting a distance between the dependent surface and the measurement three-dimensional data associated with the dependent surface based on a distance between the other design reference surface and the measured three-dimensional data associated with the other design reference surface. 11. The computer-executable program for calculating the distance between the three-dimensional CAD data and the measured three-dimensional data according to claim 10.

Images