Calibration curve generation device, calibration curve generation method, and calibration curve generation program

Abstract

To provide a calibration curve generation device, a calibration curve generation method, and a calibration curve generation program, which reduce the chances of an inspection device erroneously determining inspection results.SOLUTION: A calibration curve generation device 2 for generating a calibration curve to be referenced by an inspection device 11 configured to inspect an article based on a spectroscopic spectrum of the article as measured by a spectrometric device 10, comprises: a preprocessing unit 20 configured to preprocess multiple absorption spectra obtained by the spectrometric device 10 for multiple articles with known true values; and a calibration curve computation unit 22 configured to compute a calibration curve from the preprocessed absorption spectra and the true values for the multiple articles. The preprocessing unit 20 has a wavelength range setting unit 31 for setting a wavelength range subjected to the preprocessing.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a calibration curve generating device, a calibration curve generating method, and a calibration curve generating program. [Background technology]

[0002] Patent Document 1 discloses an inspection device that detects whether the components of a molded product are appropriate by directing the transmitted light emitted from a light source that has passed through the molded product into a sensor as signal light and analyzing the signal light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-112199 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the inspection device described in Patent Document 1 has a problem in that it analyzes signal light of unnecessary wavelengths that has passed through the molded product, which can lead to erroneous judgments of the inspection results.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a calibration curve generating device, a calibration curve generating method, and a calibration curve generating program that can reduce the likelihood of the inspection device making an erroneous judgment on the inspection results. [Means for solving the problem]

[0006] The calibration curve generating device according to the present invention is a calibration curve generating device (2) that generates a calibration curve to be referenced by an inspection device (11) that inspects an article based on the spectroscopic spectrum of the article measured by a spectroscopic measuring device (10), and includes a pre-processing unit (20) that pre-processes a plurality of absorption spectra obtained by the spectroscopic measuring device for a plurality of articles whose true values ​​are known, and a calibration curve calculation unit (22) that calculates the calibration curve from the absorption spectra after the pre-processing and the true values ​​for the plurality of articles, and the pre-processing unit has a wavelength range setting unit (31) that sets a wavelength range in which the pre-processing is performed.

[0007] With this configuration, the calibration curve generating device according to the present invention can generate a calibration curve by excluding unnecessary wavelength ranges with large variations from the absorption spectra of multiple articles whose true values ​​are known, thereby reducing the chance of the inspection device making an erroneous judgment on the inspection results.

[0008] In the calibration curve generating device according to the present invention, the wavelength range setting unit may set a wavelength range in which the evaluation value of the calibration curve is equal to or greater than a threshold value as the wavelength range of the absorption spectrum for which the preprocessing is performed.

[0009] With this configuration, the calibration curve generating device of the present invention sets the wavelength range of the absorption spectrum for which preprocessing is performed, in which the evaluation value of the calibration curve is equal to or greater than a threshold value, thereby reducing the chance of the inspection device making an erroneous judgment about the inspection results.

[0010] Furthermore, in the calibration curve generating device according to the present invention, the preprocessing unit may perform normalization for the wavelength range set by the wavelength range setting unit as the preprocessing, and may further include a normalized wavelength range setting unit that sets a wavelength range from which calculation elements to be used for performing the normalization are obtained, and the normalization may be performed based on the calculation elements of the wavelength range set by the normalized wavelength range setting unit.

[0011] With this configuration, the calibration curve generating device according to the present invention generates a calibration curve by accurately performing normalization to suppress variations between wavelengths in the absorption spectrum, thereby reducing the likelihood of the testing device making erroneous judgments about the test results.

[0012] The calibration curve generating method according to the present invention is a calibration curve generating method for generating a calibration curve to be referenced by an inspection device (11) that inspects an article based on the spectroscopic spectrum of the article measured by a spectroscopic measurement device (10), and includes a preprocessing step of preprocessing a plurality of absorption spectra obtained by the spectroscopic measurement device for a plurality of articles whose true values ​​are known, and a calibration curve calculation step of calculating the calibration curve from the absorption spectra after the preprocessing and the true values ​​for the plurality of articles, wherein the preprocessing step includes a wavelength range setting step of setting a wavelength range in which the preprocessing is performed.

[0013] In this way, the calibration curve generation method according to the present invention can generate a calibration curve by excluding unnecessary wavelength ranges with large variations from the absorption spectra of multiple articles whose true values ​​are known, thereby reducing the chance of the inspection device making an erroneous judgment on the inspection results.

[0014] The calibration curve generation program according to the present invention is a calibration curve generation program that causes a computer to generate a calibration curve to be referenced by an inspection device (11) that inspects an article based on the spectroscopic spectrum of the article measured by a spectroscopic measurement device (10), and includes a preprocessing step of preprocessing a plurality of absorption spectra obtained by the spectroscopic measurement device for a plurality of articles whose true values ​​are known, and a calibration curve calculation step of calculating the calibration curve from the absorption spectra after the preprocessing and the true values ​​for the plurality of articles, and the preprocessing step includes a wavelength range setting step of setting a wavelength range in which the preprocessing is performed.

[0015] In this way, the calibration curve generation program according to the present invention can generate a calibration curve by excluding unnecessary wavelength ranges with large variations from the absorption spectra of multiple articles whose true values ​​are known, thereby reducing the chance of the inspection device making an erroneous judgment on the inspection results. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a calibration curve generating device, a calibration curve generating method, and a calibration curve generating program that can reduce the likelihood of an inspection device making an erroneous judgment on an inspection result. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a functional block diagram of an article inspection device equipped with a calibration curve generating device according to one embodiment of the present invention. [Figure 2] FIG. 2 is a functional block diagram showing in detail the input and output of a calibration curve calculation unit that constitutes a calibration curve generating device according to one embodiment of the present invention. [Figure 3] FIG. 3 is a functional block diagram showing in detail the input and output of a calibration curve evaluation unit that constitutes a calibration curve generating device according to one embodiment of the present invention. [Figure 4] FIG. 4 is a conceptual diagram showing an example of display of a wavelength range set by a wavelength range setting unit constituting a calibration curve generating device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an article inspection system including a calibration curve generating device according to one embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the article inspection system according to this embodiment includes an article inspection device 1 and a calibration curve generating device 2.

[0019] When an item to be inspected, which is being transported individually along a transport path by a transport unit, reaches a predetermined inspection position, the item inspection device 1 irradiates light onto the item, which is in a fixed position at the predetermined inspection position, and inspects the quality of the item based on the spectral spectrum of the transmitted light that passes through the item upon irradiation with this light (also called irradiated light).

[0020] The items to be inspected include unpackaged items with an outer diameter of several to several tens of mm that can be transported individually, bite-sized items, as well as items and molded products of a predetermined shape manufactured using existing manufacturing equipment or manufacturing equipment without inspection capabilities, and especially items that do not change shape during transportation.

[0021] Examples of such articles include pharmaceutical preparations such as tablets, capsules, lozenges, and drops, as well as candy and chocolate. The following description will be given taking as an example an article to be inspected a tablet W that is circular in plan view, has a height (thickness) smaller than its diameter, and is roughly cylindrical in side view. Note that the article to be inspected is not limited to a circular shape in plan view, and articles of various shapes such as an oval shape or a polygonal shape can also be used.

[0022] Examples of the conveying unit include a conveying belt, a conveying disk, a conveying chute, and the like, which are configured to align and convey articles individually.

[0023] The article inspection device 1 according to this embodiment includes a spectroscopic measurement device 10 and an inspection device 11.

[0024] The spectroscopic measurement device 10 includes a light source unit and a light detection unit. The spectroscopic measurement device 10 irradiates a tablet W to be measured with broadband light (visible light, near-infrared to terahertz light (terahertz waves)), and measures the spectrum of the light transmitted through the tablet W in response to the irradiation of this light.

[0025] In this embodiment, the inspection device 11 is composed of a computer unit equipped with a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), a storage device such as a hard disk drive, and a communication port.

[0026] The ROM and storage device of this computer unit store a program for causing the computer device to function as the inspection device 11. That is, the CPU executes the program stored in the ROM and storage device using the RAM as a working area, causing the computer unit to function as the inspection device 11 in this embodiment.

[0027] The inspection device 11 calculates the absorbance A of the tablet W at each wavelength λ from the light intensity Ii at the wavelength λ of the reference spectrum stored in the storage device and the light intensity I at the wavelength λ of the spectrum of the tablet W measured by the spectrometer 10, as follows: A=-log 10 The absorption spectrum of the tablet W is calculated by performing calculation according to (I / Ii). In this embodiment, the spectrum measured by the spectroscopic measurement device 10 in the absence of a measurement object is used as the reference spectrum.

[0028] The inspection device 11 performs preprocessing for a predetermined wavelength range of the absorption spectrum of the tablet W. The predetermined wavelength range is received from the calibration curve generating device 2 connected via a communication port and stored in the storage device of the inspection device 11.

[0029] The preprocessing performed by the inspection device 11 is the same as the preprocessing performed by the preprocessing unit 20 of the calibration curve generating device 2 described later, and therefore will not be described again. When the preprocessing of the absorption spectrum of the tablet W is completed, the inspection device 11 refers to the calibration curve stored in the storage device and calculates a measurement value corresponding to the absorption spectrum of the tablet W.

[0030] In this embodiment, the measured value represents the content of the test component contained in the tablet W. The calibration curve is received from the calibration curve generating device 2 connected via a communication port and stored in the storage device of the inspection device 11.

[0031] The inspection device 11 judges whether the quality of the tablets W is good or bad based on the measured values. The inspection device 11 outputs a sorting signal based on the quality or bad result of the judgment to a sorting device (not shown) that sorts the tablets W into normal products and defective products. The sorting device sorts the tablets W into normal products and defective products based on the sorting signal.

[0032] The calibration curve generating device 2 generates a calibration curve to be referenced by the inspection device 11 in order to inspect the tablet W measured by the spectroscopic measurement device 10. In this embodiment, the calibration curve generating device 2 is configured by a computer device including a CPU, RAM, ROM, a storage device such as a hard disk drive, a communication port, a display device, and an input device.

[0033] The ROM and storage device of this computer device store a program for causing the computer device to function as the calibration curve generating device 2. That is, the CPU executes the program stored in the ROM and storage device using the RAM as a working area, causing the computer device to function as the calibration curve generating device 2 in this embodiment.

[0034] The display device is, for example, a liquid crystal display device. The input device is, for example, a keyboard device or a pointing device. The input device may be, for example, a touch pad integrated with the display device. A cable for communicating with the inspection device 11 is connected to the communication port.

[0035] The storage device of the calibration curve generating device 2 stores the absorption spectra of a plurality of tablets whose true values ​​are known in association with the true values. The true values ​​of the plurality of tablets are measured in advance by an apparatus capable of high-precision measurement, such as a high-performance liquid chromatography apparatus. The absorption spectra of the plurality of tablets are measured in advance by the article inspection device 1.

[0036] In this embodiment, the absorption spectra of a plurality of tablets are grouped according to true values ​​and stored in the storage device of the calibration curve generating device 2. For example, the absorption spectra of 80 tablets with a true value of around 2 are assigned to the first group. The absorption spectra of 80 tablets with a true value of around 4 are assigned to the second group. The absorption spectra of 80 tablets with a true value of around 8 are assigned to the third group. The absorption spectra of 80 tablets with a true value of around 12 are assigned to the fourth group.

[0037] The calibration curve generating device 2 includes a preprocessing unit 20, a classification unit 21, a calibration curve calculation unit 22, and a calibration curve evaluation unit .

[0038] The preprocessing unit 20 performs predetermined preprocessing on the absorption spectra stored in the storage device to convert them into a data format suitable for multivariate analysis, which will be described later. The predetermined preprocessing includes at least one of the four arithmetic operations, differentiation, integration, and normalization.

[0039] The classification unit 21 classifies the preprocessed absorption spectra into teacher data Tr and test data Te. In this embodiment, the classification unit 21 classifies the preprocessed absorption spectra of 40 tablets from each of the first to fourth groups as teacher data Tr, and classifies the preprocessed absorption spectra of the remaining 40 tablets from each of the first to fourth groups as test data Te.

[0040] 2, the calibration curve calculation unit 22 calculates a calibration curve representing the correlation between the teacher data Tr and the true value by performing multivariate analysis on the teacher data Tr and the true value associated with the teacher data Tr. The calibration curve calculation unit 22 performs multivariate analysis using, for example, simple regression analysis, multiple regression analysis, quantification type 1, quantification type 2, quantification type 3, discriminant analysis, logistic regression analysis, principal component analysis, partial least squares regression (PLS regression), factor analysis, cluster analysis, correspondence analysis, multidimensional scaling, conjoint analysis, support vector machine, decision tree, random forest, naive Bayes, neural network, deep learning, etc.

[0041] In this embodiment, the calibration curve calculation unit 22 performs multivariate analysis using PLS regression. The calibration curve calculated by the calibration curve calculation unit 22 is transmitted to the inspection device 11 via a communication port in response to an operation of the input device, for example, and stored in a storage device of the inspection device 11.

[0042] As shown in Figure 3, the calibration curve evaluation unit 23 calculates an evaluation value of the calibration curve calculated by the calibration curve calculation unit 22 using the test data Te and the true value associated with the test data Te, and evaluates the accuracy of the calibration curve based on the evaluation value.

[0043] In this embodiment, the calibration curve evaluation unit 23 calculates an evaluation value of the calibration curve based on at least one index such as the mean square error, the root mean square error, the mean absolute error, the average error, the prediction standard error, the coefficient of determination, and the coefficient of determination corrected for degrees of freedom, etc. The calibration curve evaluation unit 23 displays the calculated evaluation value on, for example, a display device.

[0044] 1, the pre-processing unit 20 has a wavelength range setting unit 31 that sets the wavelength range in which pre-processing is performed. In this embodiment, the wavelength range setting unit 31 is configured by an input device.

[0045] The wavelength range set by the wavelength range setting unit 31 is transmitted to the inspection device 11 via the communication port together with the calibration curve calculated by the calibration curve calculation unit 22 and stored in the storage device of the inspection device 11.

[0046] For example, as shown in FIG. 4, the wavelength range setting unit 31 allows a wavelength range 40 for pre-processing to be set by an input device while the absorption spectrum stored in the storage device is displayed as a graph on the display device.

[0047] Here, when a predetermined operation is performed on the input device, the preprocessed absorption spectrum is displayed on the display device in graph form instead of the absorption spectrum stored in the storage device, the wavelength range 40 is displayed so as to be superimposed on the preprocessed absorption spectrum, and the evaluation result by the calibration curve evaluation unit 23 is displayed in a region different from the preprocessed absorption spectrum.

[0048] In this way, by having the wavelength range setting unit 31 set the wavelength range while referring to the evaluation results by the calibration curve evaluation unit 23, the calibration curve generating device 2 can generate a calibration curve by excluding unnecessary wavelength ranges with large variations from the teacher data Tr.

[0049] As described above, the calibration curve generating device 2 according to this embodiment can generate a calibration curve by excluding unnecessary wavelength ranges with large variations from the absorption spectra of multiple articles whose true values ​​are known, thereby reducing the likelihood of the inspection device 11 making erroneous judgments about the inspection results.

[0050] In the above-described embodiment, an example has been described in which the wavelength range setting unit 31 is configured with an input device. However, the wavelength range setting unit 31 may set a wavelength range in which the evaluation value of the calibration curve obtained by the calibration curve evaluation unit 23 is equal to or greater than a threshold value as the wavelength range of the absorption spectrum for which preprocessing is performed.

[0051] For example, while changing the wavelength range set by wavelength range setting unit 31, preprocessing by preprocessing unit 20, calculation of the calibration curve by calibration curve calculation unit 22, and evaluation of the calibration curve by calibration curve evaluation unit 23 are repeatedly performed until the evaluation value of the calibration curve by calibration curve evaluation unit 23 becomes equal to or greater than the threshold value. By configuring in this way, it is possible to eliminate the need for an operator to set the wavelength range for preprocessing.

[0052] Furthermore, the wavelength range setting unit 31 may set the wavelength range using artificial intelligence (e.g., reinforcement learning, Bayesian statistics, or deep learning) based on the absorption spectrum stored in the storage device so that the evaluation value of the calibration curve by the calibration curve evaluation unit 23 becomes higher.

[0053] In addition, the preprocessing unit 20 may further include a normalized wavelength range setting unit that performs normalization on the wavelength range set by the wavelength range setting unit 31 as preprocessing and sets a wavelength range for obtaining calculation elements used to perform the normalization.

[0054] In this case, the preprocessing unit 20 calculates a normalized value Yi of the intensity xi of each wavelength in the wavelength range set by the wavelength range setting unit 31 (hereinafter also referred to as the "second wavelength range") based on the average value μ and standard deviation σ of the intensity in the wavelength range set by the normalized wavelength range setting unit (hereinafter also referred to as the "first wavelength range"), using the formula Yi = (xi - μ) / σ.

[0055] The first wavelength range may be the same as the second wavelength range, or may be outside the second wavelength range, or may be within the second wavelength range. Similar to the wavelength range setting unit 31, the normalized wavelength range setting unit is configured by, for example, an input device.

[0056] While embodiments of the present invention have been disclosed above, it will be apparent to those skilled in the art that modifications may be made without departing from the scope of the present invention. All such modifications and equivalents are intended to be encompassed by the following claims. [Explanation of symbols]

[0057] 2. Calibration curve generator 10 Spectrometer 11 Inspection equipment 20 Pretreatment section 22 Calibration curve calculation section 31 Wavelength range setting section

Claims

1. A calibration curve generating device (2) that generates a calibration curve to be referenced by an inspection device (11) that inspects an article based on a spectroscopic spectrum of the article measured by a spectroscopic measurement device (10), comprising: a pre-processing unit (20) that pre-processes a plurality of absorption spectra obtained by the spectroscopic measurement device for a plurality of articles whose true values ​​are known; a calibration curve calculation unit (22) that calculates the calibration curve from the absorption spectra after the pretreatment and the true values ​​for the plurality of articles, The pre-processing unit is a calibration curve generating device having a wavelength range setting unit (31) that sets a wavelength range for performing the pre-processing.

2. The calibration curve generating device according to claim 1 , wherein the wavelength range setting unit sets a wavelength range in which the evaluation value of the calibration curve is equal to or greater than a threshold value as the wavelength range of the absorption spectrum for which the preprocessing is performed.

3. The pre-treatment unit performing normalization for the wavelength range set by the wavelength range setting unit as the pre-processing; a normalization wavelength range setting unit that sets a wavelength range for obtaining calculation elements used to perform the normalization; The calibration curve generating device according to claim 1 , wherein the normalization is performed based on calculation elements of the wavelength range set by the normalization wavelength range setting unit.

4. A calibration curve generating method for generating a calibration curve to be referenced by an inspection device (11) that inspects an object based on a spectroscopic spectrum of the object measured by a spectroscopic measurement device (10), comprising: a pre-processing step of pre-processing a plurality of absorption spectra obtained by the spectroscopic measurement device for a plurality of articles whose true values ​​are known; a calibration curve calculation step of calculating the calibration curve from the post-pretreatment absorption spectra and the true values ​​for the plurality of articles, The calibration curve generating method includes a wavelength range setting step in which the pre-processing step sets a wavelength range in which the pre-processing is performed.

5. A calibration curve generation program that causes a computer to generate a calibration curve to be referenced by an inspection device (11) that inspects an item based on a spectroscopic spectrum of the item measured by a spectroscopic measurement device (10), comprising: a pre-processing step of pre-processing a plurality of absorption spectra obtained by the spectroscopic measurement device for a plurality of articles whose true values ​​are known; a calibration curve calculation step of calculating the calibration curve from the post-pretreatment absorption spectra and the true values ​​for the plurality of articles, The calibration curve generating program includes a wavelength range setting step in which the pre-processing step sets a wavelength range in which the pre-processing is performed.

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