Processing assistance device, processing assistance method, program, and measuring machine
Patent Information
- Application Number
- PCT/JP2026/008891
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-18
- Filing Date
- 2026-03-09
- Publication Date
- 2026-09-24
Smart Images
Figure JP2026008891_24092026_PF_FP_ABST
Abstract
Description
Machining support device, machining support method, program, and measuring machine
[0001] The present invention relates to a processing support device, a processing support method, a program, and a measuring machine.
[0002] Workpieces processed using a machining tool are measured at specified measurement points using measuring machines such as a three-dimensional measuring machine, and measurement values are obtained for measurement items such as dimensions and geometric tolerances. The error from the design value is then calculated using these measurement values.
[0003] Workpiece errors are fed back into the machining program applied to the machine. Conventionally, when workpiece errors are fed back into the machining program used to machine the workpiece, the machining sequence corresponding to the machining element to be corrected is corrected.
[0004] Patent Document 1 describes a numerical control device in which the measurement results of a workpiece processed using a machine tool are fed back to an NC program executed in the machine tool.
[0005] Patent No. 3827951
[0006] However, if the error in the workpiece is primarily due to a system error in the machining center, then a cumbersome process of measuring the workpiece and correcting the machining sequence based on the measurement results must be repeated for all workpieces machined using that center. Furthermore, a large number of defective products may be generated during the process of correcting the machining sequence. The apparatus described in Patent Document 1 does not solve the above problems.
[0007] This invention has been made in view of these circumstances, and aims to provide a machining support device, a machining support method, a program, and a measuring machine that eliminate the need to modify each individual machining sequence in a machining program.
[0008] A machining support device according to a first aspect of this disclosure is a machining support device comprising: a design information acquisition unit that acquires design information of a workpiece applied to a machining machine for each of a plurality of types of workpieces machined using a machining machine; a measurement information acquisition unit that acquires measurement information obtained by measuring the workpiece using a measuring machine, and acquires measurement information for each measurement point of the workpiece to which a work coordinate system is applied; an error information acquisition unit that uses the design information and measurement information to acquire the error for each measurement point to which the work coordinate system is applied for each type of workpiece; a coordinate transformation unit that transforms the measurement points to which the work coordinate system is applied to a machining machine coordinate system applied to the machining machine; and an error distribution element integration unit that represents the error for each measurement point of the workpiece transformed into the machining machine coordinate system, integrates error distribution elements generated for each type of workpiece, and generates an error distribution in the machining space of the machining machine.
[0009] Measurement information may include measured values for one or more measurement points defined on the workpiece. Measured values may be the coordinate values of the measurement points. Error information may include errors for each measurement point. Errors in multidimensional space may be represented as multidimensional vectors.
[0010] In the second embodiment of the machining support apparatus, in the first embodiment, the error distribution element integration unit may generate an error distribution by interpolating the second error distribution element of the second workpiece to the first error distribution element of the first workpiece in the overlapping region where the first machining region based on the machining position and machining orientation of the first workpiece in the machining space and the second machining region based on the machining position and machining orientation of the second workpiece of a different type from the first workpiece overlap.
[0011] The area where the first processing area and the second processing area overlap may include the area where the first processing area and the second processing area are in contact.
[0012] The processing support device according to the third embodiment may include an error interpolation unit that interpolates error data for error distribution elements, in the first or second embodiment.
[0013] The processing support device according to the fourth embodiment may include a statistical processing unit that performs statistical processing on the error for each measurement point for multiple workpieces of each workpiece type, in any one embodiment from the first to the third embodiment.
[0014] A fifth aspect of the present disclosure is a machining support method in which a computer functioning as a machining support device performs the following steps for each of a plurality of types of workpieces machined using a machining machine: acquiring workpiece design information applicable to the machining machine; acquiring measurement information obtained by measuring the workpiece using a measuring machine, and measurement information for each measurement point of the workpiece to which the workpiece coordinate system is applied; acquiring errors for each type of workpiece to which the workpiece coordinate system is applied, using the design information and measurement information; converting the measurement points to which the workpiece coordinate system is applied to the machining machine coordinate system applicable to the machining machine; and integrating error distribution elements generated for each type of workpiece, which represent the errors for each measurement point of the workpiece converted to the machining machine coordinate system, to generate an error distribution in the machining space of the machining machine.
[0015] The program according to the sixth aspect of this disclosure is a program that enables a computer functioning as a machining support device to implement the following functions for each of several types of workpieces machined using a machining machine: a function to acquire design information of the workpiece applied to the machining machine; a function to acquire measurement information obtained by measuring the workpiece using a measuring machine, which is measurement information for each measurement point of the workpiece to which the work coordinate system is applied; a function to acquire the error for each measurement point to which the work coordinate system is applied, for each type of workpiece, using the design information and measurement information; a function to convert the measurement points to which the work coordinate system is applied to the machining machine coordinate system applied to the machining machine; and a function to generate an error distribution in the machining space of the machining machine by integrating the error distribution elements generated for each type of workpiece, which represent the error for each measurement point of the workpiece converted to the machining machine coordinate system.
[0016] A measuring machine according to a seventh aspect of this disclosure is a measuring machine that measures a workpiece processed using a processing machine, and comprises: a design information acquisition unit that acquires design information of a workpiece applied to a processing machine for each of a plurality of types of workpieces; a measurement information acquisition unit that acquires measurement information obtained by measuring the workpiece, and which acquires measurement information for each measurement point of the workpiece to which a workpiece coordinate system is applied; an error information acquisition unit that uses the design information and measurement information to acquire the error for each measurement point to which a workpiece coordinate system is applied for each type of workpiece; a coordinate transformation unit that transforms the measurement points to which a workpiece coordinate system is applied to a processing machine coordinate system applied to the processing machine; and an error distribution element integration unit that represents the error for each measurement point of the workpiece transformed into a processing machine coordinate system, integrates error distribution elements generated for each type of workpiece, and generates an error distribution in the processing space of the processing machine.
[0017] According to this disclosure, using the design and measurement information of multiple types of workpieces, error distribution elements representing the error distribution in the machining space of the machine for each type of workpiece are generated. These error distribution elements for each type of workpiece are then integrated to generate the error distribution in the machining space of the machine. This allows the machining program to be modified for systematic errors using the error distribution in the machining space of the machine, eliminating the need to modify each individual machining sequence for each machining element.
[0018] This is a schematic diagram of a machining system equipped with a machining center and a measuring machine. This is a schematic diagram showing an example of an error calculation method. This is a graph showing an example of an error distribution to which the machining center coordinate system is applied. This is a graph showing an optimized error distribution with offsets occurring between error distributions for each type of workpiece. This is a schematic diagram representing the distribution of probing points to which the machining center coordinate system is applied. This is an explanatory diagram of a specific example of merging error distributions. This is a functional block diagram of a machining support device according to an embodiment. This is an overall configuration diagram of a three-dimensional measuring machine according to an embodiment.
[0019] The embodiments for carrying out this disclosure will be described in detail below with reference to the attached drawings. In the following description and attached drawings, the same components are denoted by the same reference numerals, and redundant descriptions are omitted. Furthermore, when multiple components are listed as examples in the following embodiments, it can be interpreted that at least one of the multiple components is included.
[0020] [Example of a Processing System Configuration] Figure 1 is a schematic diagram of a processing system equipped with a processing machine and a measuring machine. The processing system 1 shown in the figure includes a processing machine 2 that processes material M based on the design information of the workpiece W, and a measuring machine 3 that performs measurements at measurement points specified on the workpiece W. The processing system 1 also includes a processing support device. The processing support device is not shown in Figure 1. The processing support device is denoted by reference numeral 100 and is shown in Figure 7.
[0021] The design information includes the overall shape and dimensions of the workpiece W, as well as the shape and dimensions of machining elements such as holes. The design information may also include tolerances for numerical values such as dimensions. The design information may be represented as a three-dimensional model.
[0022] An example of a processing machine 2 is an NC processing machine to which numerical control is applied. An NC processing machine processes material M by executing an NC processing program that specifies the operating conditions and processing conditions for material M. Note that NC is an abbreviation for Numerical Control. A processing machine may also be called a processing device.
[0023] The measuring machine 3 performs measurements at one or more measurement points specified on the workpiece W and calculates the error for each measurement point. An example of the measuring machine 3 is a three-dimensional measuring machine. The three-dimensional measuring machine performs measurements at measurement points specified on the workpiece W and obtains measurement values for measurement items such as dimensions and geometric tolerances. The measuring machine may also be referred to as a measuring device.
[0024] Examples of geometric tolerances include straightness, flatness, roundness, cylindricity, profile (line), profile (surface), parallelism, perpendicularity, inclination, position, concentricity (coaxiality), symmetry, circumferential runout, and total runout. Geometric tolerances specified in ISO 8015:1985 may be applied.
[0025] Based on the measured values at each measurement point, the error from the design value of the workpiece W is calculated for each measurement point. The error can be broadly classified into at least one of the following: systematic errors of the processing machine 2, systematic errors of the measuring machine 3, random errors that occur when processing the workpiece W, and random errors that occur when measuring the workpiece W.
[0026] In the case of mass-produced products, random errors that occur when processing the workpiece W, and random errors that occur when measuring the workpiece W, can be eliminated by performing processes such as averaging the errors for each measurement point and taking the median value of the errors for each measurement point.
[0027] Normally, the measuring instrument 3 is inspected and calibrated at predetermined intervals, such as once a year, to ensure its measurement accuracy. During operation of the measuring instrument 3, the utmost care is taken to maintain its measurement accuracy. Examples of such care include not applying strong external forces to the measuring instrument 3 and accelerating the replacement cycle of parts that come into contact with the workpiece W.
[0028] Assuming that the measurement error caused by the measuring device 3 is sufficiently small, additional machining is performed on the workpiece W, and the machining program applied to the machining machine 2 is modified, resulting in a workpiece W that meets the predetermined requirements.
[0029] [Example of Error Calculation Method] Figure 2 is a schematic diagram showing an example of an error calculation method. Below, an example is given where a three-dimensional measuring machine is used as the measuring machine 3 shown in Figure 1. The figure illustrates the procedure for an error calculation method in which the error of the workpiece W caused by the processing machine 2 is calculated from the measurement results of the workpiece W obtained using the three-dimensional measuring machine. Note that the calculation may be referred to as calculation or calculation.
[0030] The error calculation method for workpiece W is implemented using a computer equipped with a processor and memory, wherein the processor executes a program stored in memory to perform each step of the error calculation method for workpiece W.
[0031] The method for calculating the error of workpiece W may include a step in which a computer acquires various information entered by the operator. Note that the method for calculating the error of workpiece W is just one example of a component in the processing support method of this disclosure.
[0032] In the method for calculating the error of workpiece W, position and orientation information for each workpiece W, representing the position of workpiece W in the machining center 2, is obtained. If R is the rotation matrix representing the orientation of workpiece W in the machining center coordinate system applied to the machining space of the machining center 2, and t is the vector representing the position of workpiece W in the machining center coordinate system, then the transformation from the workpiece coordinate system to the machining center coordinate system is expressed as the matrix in Equation 1.
[0033] The position of the workpiece W in the processing machine 2 is an example of a processing position in this disclosure, and the orientation of the workpiece W in the processing machine 2 is an example of a processing orientation in this disclosure.
[0034] In the error calculation method for workpiece W, a 3D CAD model of workpiece W is obtained as design information for each type of workpiece. The acquisition of the 3D CAD model may include obtaining pre-generated 3D CAD models for each type of workpiece, and generating 3D CAD models from CAD data for each type of workpiece. Note that 3D represents three dimensions, and D is an abbreviation for Dimensional. Also, CAD is an abbreviation for Computer-Assisted Drafting or Computer-Aided Drafting.
[0035] Here, the type of workpiece is defined based on differences in design information. Workpieces W to which the same design information applies are recognized as workpieces W of the same type, while workpieces W to which different design information applies are recognized as workpieces W of different types.
[0036] The type of workpiece may be defined based on the machining position of the workpiece W, or based on the machining orientation of the workpiece W. For example, workpieces W with the same design information but different machining positions and orientations are considered to be different types of workpieces W.
[0037] In step S10, for each of the multiple types of workpieces W, the coordinate values of all probing points in each of the multiple workpieces W are obtained. Figure 2 illustrates three different types of workpieces: type A, type B, and type C.
[0038] The coordinate values of the probing points may be obtained using a three-dimensional Cartesian coordinate system with mutually orthogonal X, Y, and Z axes. The coordinate values for each probing point obtained in step S10 are to be obtained using the work coordinate system.
[0039] In step S12, for all workpieces W for which coordinate values for each probing point have been obtained, the probing points are best-fitted to the 3D CAD model, and error vectors are obtained as error information for each probing point.
[0040] In other words, in step S12, the number of probing points p is equal to the total number of probing points for each workpiece W. ｉ = [x ｉ , y ｉ , z ｉ ] and error vector E ｉ = [u ｉ ,v ｉ ,w ｉ A pair is obtained with ]. The total number of probing points for each workpiece W may be a different value for each type of workpiece. Note that i is an integer from 1 to the total number of probing points.
[0041] In step S14, for multiple workpieces W of the same type, an averaging process or median filtering process is performed on the error vector for each probing point to obtain the average error for each type of workpiece. Median filtering is a process that derives the median value.
[0042] In step S14, statistical processing may be performed to calculate a representative error vector for each probing point, such as extracting the mode of the error vector for each probing point. Random errors can be eliminated as a result of the statistical processing in step S14.
[0043] In step S16, the coordinate values of the probing point to which the work coordinate system is applied are converted to the coordinate values of the machine coordinate system. Position and orientation information shown in Equation 1 is used for the conversion from the work coordinate system to the machine coordinate system.
[0044] In other words, in step S16, based on the average error for each type of workpiece to which the machine coordinate system is applied, which is derived from the average error for each type of workpiece to which the work coordinate system is applied, the error distribution in the machining space of the machine 2 to which the machine coordinate system is applied is obtained for each type of workpiece.
[0045] In step S18, error vectors are interpolated for the error distribution for each type of workpiece to which the machine coordinate system is applied, for positions other than the probing point in the machining space of the machine 2. The interpolated error vectors are an example of error data to be interpolated for the error distribution elements of this disclosure.
[0046] Furthermore, in step S18, the error distributions for each workpiece type are merged to obtain an error distribution to which the machine coordinate system is applied. In merging the error distributions for each workpiece type, the offsets that occur between the error distributions for each workpiece type are optimized.
[0047] Through steps S10 to S18, an error distribution representing the systematic error of the machining center 2 is obtained. The error distribution in the machining space of the machining center 2 is fed back to the machining program applied to the machining center 2.
[0048] Figure 3 is a graph showing an example of an error distribution to which the machine coordinate system is applied. The figure illustrates the error distribution on any one axis of the three-dimensional Cartesian coordinate system. The horizontal axis of graph G1 shown in Figure 3 represents the x-axis in the machine coordinate system.
[0049] The vertical axis of graph G1 represents the value of the error vector. The value of the error vector may be a scalar value calculated as the square root of the sum of the squares of each component of the error vector. Graph G1 shows the normalized value of the error vector. The same applies to graph G2 shown in Figure 4.
[0050] The probing points for each type of workpiece, and the error vectors for each probing point, which are represented using coordinate values to which the machine coordinate system is applied, exist discretely within the machine coordinate system, and an offset occurs in the error vector for each type of workpiece.
[0051] In other words, because the error vector is determined after the best-fit processing is performed for each type of workpiece in the work coordinate system, the error distribution of workpiece type A, when converted to the machine coordinate system, is not continuous with the error distribution of workpiece type B. Similarly, the error distribution of workpiece type B and the error distribution of workpiece type C are also not continuous. For both the y-axis and z-axis in the machine coordinate system, an offset occurs in the error vector for each type of workpiece, similar to graph G1 shown in Figure 3, resulting in a non-continuous error distribution.
[0052] Figure 4 is a graph showing an optimized error distribution with offsets occurring between the error distributions for each type of workpiece. The horizontal axis of graph G2 shown in the figure is the x-axis, which is any axis of the machining coordinate system, similar to the horizontal axis of graph G1 shown in Figure 3, and the vertical axis of graph G2 is the value of the error vector, similar to the vertical axis of graph G1.
[0053] In step S18, shown in Figure 2, it is assumed that the error distribution for each type of workpiece is continuous, as shown in graph G2 in Figure 4, and a systematic error distribution in the machining space of the machining machine 2 is obtained by merging the error distributions for each type of workpiece.
[0054] The machining program applied to the machining center 2 can be modified based on the error distribution exemplified as graph G2 in Figure 4, eliminating the need to modify each individual machining sequence for each type of workpiece and each machining element. The error distributions for workpiece type A, workpiece type B, and workpiece type C are examples of the error distribution elements of this disclosure.
[0055] [Outline of Error Distribution Merging] Figure 5 is a schematic diagram illustrating the distribution of probing points to which a processing machine coordinate system is applied. In this diagram, the xy plane in a processing space to which the processing machine coordinate system is applied is illustrated. Probing points p on a workpiece WA belonging to workpiece type A ＮＣ Ａｉ , and probing points p on a workpiece WB belonging to workpiece type B ＮＣ Ｂｊ are illustrated.
[0056] In this diagram, a workpiece WA that is a rectangular parallelepiped having three holes H1, H2, and H3, and a workpiece WB that is a cylinder having three holes H4, H5, and H6 are illustrated as examples. A processing region of the workpiece WA where the probing points p ＮＣ Ａｉ of the workpiece WA exist, and a processing region of the workpiece WB where the probing points p ＮＣ Ｂｊ of the workpiece WB exist partially overlap each other.
[0057] Note that the workpiece WA is an example of the first workpiece of the present disclosure, and the workpiece WB is an example of the second workpiece of the present disclosure.
[0058] As illustrated in Figure 5, in the processing machine coordinate system, the probing points p ＮＣ Ａｉ of the workpiece WA, and the probing points p ＮＣ Ｂｊ of the workpiece WB are unevenly distributed. A set of a plurality of error vectors E ＮＣ Ａｉ for the workpiece WA, and a set of a plurality of error vectors E ＮＣ Ｂｊ for the workpiece WB need to be optimized after the following interpolation is performed to superimpose the sets.
[0059] As an example of a method for interpolating unevenly distributed data, Radial Basis Function Interpolation can be mentioned. For example, with a function that attenuates around 0, such as a Gaussian function, used as a basis function φ(r), an error vector at an arbitrary position p in the processing machine coordinate system is derived using s(p) represented by Equation 2, and interpolation of error vectors with respect to the error distribution of the processing machine coordinate system is realized.
[0060] P in Equation 2 ＮＣ ｉ This represents the probing point to which the machine coordinate system is applied. The coefficient vector w in Equation 2. ｉ This can be determined in advance using Equation 3.
[0061] Next, an offset term is added to the error for each type of workpiece, and the offset in the error distribution for each type of workpiece is optimized.
[0062] Let m be the index of the workpiece type, and for workpieces of the type with index m, the probing point is P. ＮＣ ｍ，ｉ Let the error vector be E ＮＣ ｍ，ｉ Let the offset value be c ｍ Let's assume that the offset term is added to s. ｍ (p, c ｍ This is expressed as equation 4.
[0063] Offset term c in Equation 4 ｍ For this, the error function ε(c) is expressed as equation 5. １ , ..., c Ｍ The error function ε(c) is defined. １ , ..., c Ｍ Nonlinear optimization is performed on c １ , ..., c Ｍ The solution is calculated. Note that M is the total number of work types. Also, in order to use work types with an index of 0 as the basis, c ０ It is set to = 0.
[0064] In Equation 5, n is an index representing the type of work, and m ≠ n. ｍ，ｎ，ｉ This is expressed as equation 6.
[0065] p in Equation 6 ＮＣ ｎ，ｉ The case where the workpiece m is within the effective range is when there are multiple probing points p in the workpiece W whose workpiece type index is m.ＮＣ ｍ，ｉ Within the convex hull formed by , there is a probing point p of workpiece W whose workpiece type index is n. ＮＣ ｎ，ｉ This indicates that it is included.
[0066] Also, v in equation 5 ｍ，ｎ，ｉ This can be expressed as equation 7 below.
[0067] p in Equation 7 ＮＣ ｍ，ｊ The case where the workpiece n is within the valid range is when there are multiple probing points p in the workpiece W whose workpiece type index is n. ＮＣ ｎ，ｊ Within the convex hull formed by this, there is a probing point p of workpiece W whose workpiece type index is m. ＮＣ ｍ，ｊ This indicates that it is included.
[0068] In this way, for multiple workpieces W of different types, the offset between the error distributions for each workpiece type is optimized, the merging of error distributions for different workpiece types is achieved, and the error distribution in the machining space of the machining machine 2 is derived based on the measurement data of multiple types of workpieces machined using the machining machine 2.
[0069] [Specific Example of Error Distribution Merging] Figure 6 is an explanatory diagram of a specific example of error distribution merging. The figure shows work W with a work type index of 0. ０ Probing point p in ＮＣ ０，ｉ , and workpiece W whose workpiece type index is 1 １ Probing point p in ＮＣ １，ｉ This is schematically illustrated. Below are two workpieces W of different types. ０ , and work W １ The merging of error distributions in the machine coordinate system will be explained.
[0070] Work W ０ The probing point is p ＮＣ ０，０ From probing point p ＮＣ ０，５５has 56 probing points up to this point, and an error vector is calculated for each of the 56 probing points. Work W １ has probing point p ＮＣ １，０ to probing point p ＮＣ １，１５ has 16 probing points up to this point, and an error vector is calculated for each of the 16 probing points.
[0071] Work W ０ error s at any point p in the processing machine coordinate system interpolated from the error of ０ (p, c ０ ) is expressed as Equation 8.
[0072] Further, error s at any point p in the processing machine coordinate system interpolated based on the error of work W １ error s at any point p in the processing machine coordinate system interpolated based on the error of １ (p, c １ ) is expressed as Equation 9.
[0073] s expressed as Equation 8 ０ (p, c ０ ) and s expressed as Equation 9 １ (p, c １ ), the offset value c is adjusted so that ０ and offset value c １ are optimized. That is, the offset value c ０ and offset value c １ may match, or may differ within a practical range. When there are two types of workpieces as illustrated in FIG. 6, the error function ε(c to be minimized １ ) is expressed as Equation 10. However, c in Equation 8 ０ is set to 0.
[0074] Here, referring to Equation 6, u in Equation 10 ｍ，ｎ，ｉ is defined as shown in Equation 11.
[0075] Work 0 in Equation 11 is the workpiece W illustrated in FIG. 6 ０ represents. p in Equation 11 ＮＣ １，ｉmeans that when is within the effective range of workpiece 0, the workpiece W ０ probing point p ＮＣ ０，ｉ is within the convex hull formed by the workpiece W １ probing point p ＮＣ １，ｉ .
[0076] That is, the workpiece W ０ probing point p ＮＣ ０，ｉ is located within the convex hull formed by the workpiece W １ probing point p ＮＣ １，８ , probing point p ＮＣ １，９ , probing point p ＮＣ １，１０ , and probing point p ＮＣ １，１１ are applied to u expressed as Equation 11 ０，１，ｉ . Furthermore, v in Equation 10 ｍ，ｎ，ｊ is defined as shown in Equation 12.
[0077] Workpiece 1 in Equation 12 refers to the workpiece W illustrated in FIG. 6 １ . p in Equation 12 ＮＣ ０，ｊ means that when is within the effective range of workpiece 1, the workpiece W １ probing point p ＮＣ １，ｊ is within the convex hull formed by the workpiece W ０ probing point p ＮＣ ０，ｊ .
[0078] That is, the workpiece W ０ probing point p ＮＣ ０，１６ , probing point p ＮＣ ０，１７ , and probing point p ＮＣ ０，１８ are applied to v expressed as Equation 12 ０，１，ｊ .
[0079] The error function ε(c to be minimized expressed as Equation 10 １ ) is as shown in Equation 13.
[0080] The method of merging error distributions in a two-dimensional plane, as illustrated here, can be extended to three-dimensional space to obtain the three-dimensional error distribution in the machining space of the machining center 2.
[0081] Note: Work W ０ This is an example of the first work of this disclosure, and work W １ This is an example of the second workpiece of this disclosure. Workpiece W is shown in Figure 6. ０ Probing point p ＮＣ ０，ｉ A shape including is an example of the first processing area of the present disclosure, and workpiece W １ Probing point p ＮＣ １，ｉ A shape including this is an example of the second processing area of this disclosure.
[0082] Workpiece W shown in Figure 6 ０ Probing point p ＮＣ ０，ｉ Shape including and workpiece W １ Probing point p ＮＣ １，ｉ A region in which the shape including the overlapping area is an example of an overlapping region in which the first processing area and the second processing area of this disclosure overlap.
[0083] Work W ０ Probing point p ＮＣ ０，ｉ In contrast, Work W １ Probing point p ＮＣ １，８ , probing point p ＮＣ １，９ , probing point p ＮＣ １，１０ , and probing point p ＮＣ １，１１ The interpolation process is an example of the process of interpolating the second error distribution element of the second workpiece to the first error distribution element of the first workpiece of the present disclosure.
[0084] [Example of the configuration of the machining support device] Figure 7 is a functional block diagram of the machining support device according to the embodiment. The machining support device 100 includes a posture position information acquisition unit 102. The posture position information acquisition unit 102 acquires posture position information which includes the position information of the material to be machined M in the machining space of the machining machine 2, and the posture information of the material M. The posture position information acquisition unit 102 may acquire the machining conditions set for the machining machine 2 and acquire the position information of the material M and the posture information of the material M from the machining conditions. An example of posture position information is a combination of the position vector t and the rotation matrix R of Equation 1. Note that the position information of the material to be machined M may be grasped as the position information of the workpiece W, and the posture information of the material to be machined M may be grasped as the posture information of the workpiece W.
[0085] The machining support device 100 includes a design information acquisition unit 104. The design information acquisition unit 104 acquires design information for the workpiece W. The design information acquisition unit 104 may acquire a 3D CAD model of the workpiece W as design information for the workpiece W, acquire information that forms the basis of the 3D CAD model of the workpiece W, and acquire a 3D CAD model of the workpiece W from the information that forms the basis of the 3D CAD model of the workpiece W.
[0086] The machining support device 100 includes a measurement information acquisition unit 106. The measurement information acquisition unit 106 acquires measurement information of the workpiece W from the measuring machine 3. The measurement information acquisition unit 106 may perform step S10 in Figure 2 to acquire the coordinate values of each probing point to which the workpiece coordinate system is applied as measurement information. The measurement information acquisition unit 106 may acquire measurement information associated with identification information representing the type of workpiece, such as an index of the type of workpiece.
[0087] The machining support device 100 includes a best-fit processing unit 108. The best-fit processing unit 108 executes step S12 to perform a best-fit process that best fits the measurement information of the workpiece W to the 3D CAD model of the workpiece W. An example of the best-fit process is a process that superimposes the measurement information onto the design information so that the sum of the squares of the errors between the design information and the measurement information is minimized.
[0088] The machining support device 100 includes an error calculation unit 110. The error calculation unit 110 calculates the error of measurement information relative to design information. The error calculation unit 110 may perform step S12 to calculate an error vector for each probing point of the workpiece W. Note that the error calculation unit 110 is an example of an error information acquisition unit of this disclosure.
[0089] The processing support device 100 includes a statistical processing unit 111. The statistical processing unit 111 executes step S14 to perform statistical processing, such as error averaging, for multiple workpieces W of each type of workpiece.
[0090] The machining support device 100 includes a coordinate transformation unit 112. The coordinate transformation unit 112 executes step S16 to perform a coordinate transformation process that uses the position and orientation information of each workpiece W to convert the coordinate values of the workpiece coordinate system to the coordinate values of the machining center coordinate system.
[0091] The machining support device 100 includes an error distribution generation unit 114. The error distribution generation unit 114 executes step S18 to generate an error distribution in the machining space of the machining machine 2, which represents the systematic error of the machining machine 2.
[0092] The error distribution generation unit 114 may include an interpolation processing unit and a merge processing unit. The interpolation processing unit and the merge processing unit are not limited to being integrated into the error distribution generation unit 114, and may be configured as separate processing units. The error distribution generation unit 114 is an example of the error interpolation unit and an example of the error distribution element integration unit of this disclosure.
[0093] The machining support device 100 includes an error distribution storage unit 116 that stores error distributions. The error distributions stored in the error distribution storage unit 116 may be updated periodically or as needed. The error distribution storage unit 116 may store error distributions for each of the multiple machining centers 2 that are associated with identification information for each of the machining centers 2.
[0094] The machining support device 100 includes an error distribution output unit 118 that outputs an error distribution to the machining machine 2. The error distribution output unit 118 transmits a signal representing the error distribution in a format corresponding to the communication format between the machining support device 100 and the machining machine 2 to the machining machine 2. The communication between the machining support device 100 and the machining machine 2 may be wired or wireless.
[0095] [Example of application to a program] A program that enables a computer to implement some or all of the various functions of the processing support apparatus 100 according to the embodiment can be stored on a computer-readable medium, such as an optical disk, magnetic disk, semiconductor memory, or other tangible non-temporary information storage medium, and the program or program product can be provided through the information storage medium.
[0096] Alternatively, instead of storing and applying a program on a tangible, non-temporary computer-readable medium as described above, it is also possible to provide program signals as a download service using telecommunication lines.
[0097] Furthermore, some or all of the functions of the processing support device 100 may be implemented as cloud computing and provided as SaaS. SaaS is an abbreviation for Software as a Service.
[0098] [Specific Example of a Measuring Machine] Figure 8 is an overall configuration diagram of a three-dimensional measuring machine according to an embodiment. In this figure, a three-dimensional measuring machine 10 is shown as a specific example of the measuring machine 3 shown in Figure 1. The three-dimensional measuring machine 10 measures the shape of the measurement elements of the workpiece W while displacing the position and orientation of the probe 12a. The XYZ axes in Figure 8 are a machine coordinate system determined based on the machine coordinate origin unique to the three-dimensional measuring machine 10.
[0099] As shown in Figure 8, the three-dimensional measuring machine 10 comprises a base plate 16 mounted on a plurality of legs 14, a right Y carriage 18R and a left Y carriage 18L erected at both ends of the base plate 16, and an X guide 20 connecting the upper parts of the right Y carriage 18R and the left Y carriage 18L. The right Y carriage 18R, the left Y carriage 18L and the X guide 20 constitute a gantry frame 22.
[0100] Sliding surfaces are formed on the upper and side surfaces of both ends of the surface plate 16 in the X-axis direction, on which the right Y carriage 18R and the left Y carriage 18L slide along the Y-axis direction. In addition, air bearings (not shown) are provided on the right Y carriage 18R and the left Y carriage 18L at positions facing the sliding surfaces of the surface plate 16. As a result, the right Y carriage 18R and the left Y carriage 18L can move freely in the Y-axis direction together with the X guide 20.
[0101] An X-carriage 24 is attached to the X-guide 20. The X-guide 20 has a sliding surface formed along the X-axis direction on which the X-carriage 24 slides. In addition, an air bearing (not shown) is provided on the X-carriage 24 at a position opposite to the sliding surface of the X-guide 20. This allows the X-carriage 24 to move freely in the X-axis direction.
[0102] A Z-carriage (also called a Z-spindle) 26 is attached to the X-carriage 24. The X-carriage 24 is also provided with an air bearing (not shown) for Z-axis direction guidance, which guides the Z-carriage 26 in the Z-axis direction. As a result, the Z-carriage 26 is held by the X-carriage 24 so as to be movable in the Z-axis direction. A probe head 12 is attached to the lower end of the Z-carriage 26.
[0103] The probe head 12 holds the base end of the contact-type probe 12a. The base end of the stylus 12b is attached to the tip of the probe 12a. A contact element 12c is attached to the tip of the stylus 12b. The stylus 12b and the contact element 12c constitute the measuring element of the probe 12a. The type of probe 12a is not particularly limited.
[0104] The probe 12a is rotated by a drive unit (not shown) around two mutually orthogonal rotation axes (not shown).
[0105] The three-dimensional measuring machine 10 is equipped with drive units that include a Y-axis drive unit for moving the gantry frame 22 in the Y-axis direction, an X-axis drive unit for moving the X carriage 24 in the X-axis direction, and a Z-axis drive unit for moving the Z carriage 26 in the Z-axis direction. Each axis drive unit is composed of a known drive mechanism including a motor. This makes it possible to move the probe head 12 and probe 12a in the three axes of X, Y, and Z.
[0106] A linear scale (not shown) for detecting the Y-axis position is provided at the right Y-carriage 18R side end of the surface plate 16. Additionally, a linear scale (not shown) for detecting the X-axis position is provided on the X-guide 20, and a linear scale (not shown) for detecting the Z-axis position is provided on the Z-carriage 26.
[0107] The right Y carriage 18R is equipped with a Y-axis position detection head (not shown) for reading a linear scale for detecting the Y-axis position. The X carriage 24 is equipped with an X-axis position detection head (not shown) for reading a linear scale for detecting the X-axis position, and a Z-axis position detection head (not shown) for reading a linear scale for detecting the Z-axis position. Furthermore, the probe head 12 is equipped with a rotation angle detection unit (not shown), such as a rotary encoder, for detecting the rotation angle of the probe 12a.
[0108] Based on the detection results of the direction position detection heads for each of the XYZ axes and the detection results of the rotation angle detection unit, the three-dimensional measuring machine 10 detects the coordinates in the XYZ axis direction of each measurement point (such as the inner surface) when the contact element 12c at the tip of the probe 12a contacts each measurement point (such as the inner surface) of the measurement element of the workpiece W.
[0109] The three-dimensional measuring machine 10 is equipped with a drive controller 32 that controls the drive unit to control the movement of the probe head 12, that is, the displacement of the position and orientation of the probe 12a (stylus 12b). The three-dimensional measuring machine 10 has an automatic measurement mode in which measurements are performed automatically and a manual measurement mode in which measurements are performed manually.
[0110] Furthermore, the drive controller 32 is provided with a controller operation unit 32a for instructing the direction of movement of the probe 12a. Therefore, in manual measurement mode, the drive controller 32 displaces the position and orientation of the probe 12a by controlling the drive unit in accordance with the manual operation received by the controller operation unit 32a. The controller operation unit 32a may be equipped with a joystick (not shown) or the like.
[0111] The drive controller 32 is connected to a contact detection sensor (not shown) of the probe 12a, a direction position detection head (not shown) for each of the XYZ axes (not shown), and a rotation angle detection unit (not shown). The moment the contact detection sensor detects that the contact element 12c of the probe 12a has come into contact with a measurement point of the workpiece W, the drive controller 32 acquires the detection results from the direction position detection head and the rotation angle detection unit for each of the XYZ axes, and detects the coordinates of each measurement point in the XYZ axis direction. The coordinates of each measurement point are output from the drive controller 32 to the computer 34.
[0112] The computer 34 is connected to the drive controller 32 via various communication interfaces such as a LAN (Local Area Network) to enable data communication.
[0113] Computer 34 has the software program 34a installed. By executing the software program 34a, computer 34 performs various measurement operations, including acquiring the coordinates of each measurement point.
[0114] The computer 34 includes an arithmetic circuit composed of various processors and memory. These various processors include CPUs (Central Processing Units), GPUs (Graphics Processing Units), ASICs (Application Specific Integrated Circuits), and programmable logic devices [e.g., SPLDs (Simple Programmable Logic Devices), CPLDs (Complex Programmable Logic Devices), and FPGAs (Field Programmable Gate Arrays)]. The various functions of the computer 34 may be implemented by a single processor, or by multiple processors of the same or different types.
[0115] The computer 34 shown in Figure 8 may include a computer that functions as a machining support device as shown in Figure 7. That is, the computer 34 may function as a control device for the three-dimensional measuring machine 10, or it may function as a machining support device 100 that uses the measurement results of the three-dimensional measuring machine 10 to acquire the error distribution of the machining coordinate system in the machining machine 2.
[0116] The three-dimensional measuring machine 10 may be equipped with a computer separate from the computer 34 that implements the functions of various processing units of the machining support device 100 shown in Figure 7. In this embodiment, the computer functioning as the machining support device 100 may be electrically connected to the computer 34 for flexible data communication. The computer functioning as the machining support device 100 and the computer 34 may share some processing units.
[0117] As a specific example of the measuring machine 3 shown in Figure 1, Figure 8 shows a contact-type three-dimensional measuring machine 10 that measures the workpiece W by bringing a contact element 12c into contact with the workpiece W. However, the measuring machine 3 shown in Figure 1 may be a non-contact measuring method.
[0118] [Effects of the Embodiment] The processing support apparatus and processing support method according to the embodiment can obtain the following effects.
[0119] [1] For each of the multiple types of workpieces W, a pair of probing points to which the workpiece coordinate system is applied and an error vector for each probing point is obtained. The probing points to which the workpiece coordinate system is applied are converted to the machine coordinate system, and the error vectors are interpolated for positions other than the probing points, generating an error distribution for each type of workpiece in the machining space of the machine 2. The error distributions for each of the multiple types of workpieces W are merged to generate an error distribution for the entire machining space of the machine 2. This makes it possible to systematically correct errors in the machining program using this error distribution.
[0120] [2] For the overlapping area between the machining area of workpiece WA and the machining area of workpiece WB, the error of workpiece WB is interpolated into the error distribution of workpiece WA. This generates an error distribution for the entire machining space in which the error distribution of workpiece WA and the error distribution of workpiece WB are continuously connected within the machining space of the machining machine 2.
[0121] [3] Radial basis function interpolation is applied to the interpolation of the error vector. This enables a favorable interpolation process for the error vector for each probing point that is unevenly distributed in the machining space.
[0122] [4] For each type of workpiece, statistical processing such as averaging and median extraction is performed on the error vectors for each probing point in multiple workpieces W. As a result, an error distribution is generated based on the error vectors from which random errors for each workpiece W have been eliminated.
[0123] [5] The measurement information is made to best fit the design information. This makes it possible to feed back the error factors of the workpiece W to the machining center 2.
[0124] This disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the technical idea of this disclosure.
[0125] 1...Processing system, 2...Processing machine, 3...Measuring machine, 10...Three-dimensional measuring machine, 34...Computer, 100...Processing support device, 102...Position and orientation information acquisition unit, 104...Design information acquisition unit, 106...Measurement information acquisition unit, 108...Best fit processing unit, 110...Error calculation unit, 111...Statistical processing unit, 112...Coordinate transformation unit, 114...Error distribution generation unit
Claims
1. A machining support device comprising: a design information acquisition unit that acquires design information of a workpiece applied to a machining machine for each of several types of workpieces machined using the machining machine; a measurement information acquisition unit that acquires measurement information obtained by measuring the workpiece using a measuring machine, and which acquires measurement information for each measurement point of the workpiece to which the workpiece coordinate system is applied; an error information acquisition unit that uses the design information and the measurement information to acquire the error for each measurement point to which the workpiece coordinate system is applied, for each type of workpiece; a coordinate transformation unit that transforms the measurement points to which the workpiece coordinate system is applied to the machining machine coordinate system applied to the machining machine; and an error distribution element integration unit that represents the error for each measurement point of the workpiece transformed into the machining machine coordinate system, and integrates error distribution elements generated for each type of workpiece to generate an error distribution in the machining space of the machining machine.
2. The machining support apparatus according to claim 1, wherein the error distribution element integration unit generates the error distribution by interpolating the second error distribution element of the second workpiece to the first error distribution element of the first workpiece in the overlapping region where the first machining region based on the machining position and machining orientation of the first workpiece in the machining space and the second machining region based on the machining position and machining orientation of a second workpiece of a different type from the first workpiece overlap.
3. The machining support apparatus according to claim 1, further comprising an error interpolation unit for interpolating error data with respect to the error distribution elements.
4. The machining support apparatus according to claim 1, further comprising a statistical processing unit that performs statistical processing on the error for each measurement point for a plurality of workpieces of each type.
5. A machining support method comprising: a computer functioning as a machining support device, which performs the following steps for each of several types of workpieces machined using a machining machine: acquiring design information of the workpiece applied to the machining machine; acquiring measurement information obtained by measuring the workpiece using a measuring machine, and measuring measurement information for each measurement point of the workpiece to which the work coordinate system is applied; acquiring the error for each measurement point to which the work coordinate system is applied, for each type of workpiece, using the design information and the measurement information; converting the measurement points to which the work coordinate system is applied to the machining machine coordinate system applied to the machining machine; and integrating error distribution elements generated for each type of workpiece, which represent the error for each measurement point of the workpiece converted to the machining machine coordinate system, to generate an error distribution in the machining space of the machining machine.
6. A program that enables a computer functioning as a machining support device to implement the following functions for each of several types of workpieces machined using a machining machine: a function to acquire design information of the workpiece applied to the machining machine; a function to acquire measurement information obtained by measuring the workpiece using a measuring machine, with measurement information for each measurement point of the workpiece to which the workpiece coordinate system is applied; a function to acquire the error for each measurement point to which the workpiece coordinate system is applied, for each type of workpiece, using the design information and the measurement information; a function to convert the measurement points to which the workpiece coordinate system is applied to the machining machine coordinate system applied to the machining machine; and a function to generate an error distribution in the machining space of the machining machine by representing the error for each measurement point of the workpiece converted to the machining machine coordinate system and integrating the error distribution elements generated for each type of workpiece.
7. A non-temporary and computer-readable recording medium on which the program described in claim 6 is recorded.
8. A measuring machine for measuring a workpiece processed using a processing machine, comprising: a design information acquisition unit for acquiring design information of the workpiece applied to the processing machine for each of a plurality of types of workpieces; a measurement information acquisition unit for acquiring measurement information obtained by measuring the workpiece, which is measurement information for each measurement point of the workpiece to which the workpiece coordinate system is applied; an error information acquisition unit for acquiring the error for each measurement point to which the workpiece coordinate system is applied, for each type of workpiece, using the design information and the measurement information; a coordinate transformation unit for transforming the measurement points to which the workpiece coordinate system is applied to the processing machine coordinate system applied to the processing machine; and an error distribution element integration unit for integrating error distribution elements generated for each type of workpiece, which represent the error for each measurement point of the workpiece transformed into the processing machine coordinate system, to generate an error distribution in the processing space of the processing machine.